New upstream version 6.9.4upstream/6.9.4

75 files changed, 3350 insertions, 2775 deletions

diff --git a/src/Makefile.windows b/src/Makefile.windows
index 762cf07..1e87504 100644
--- a/src/Makefile.windows
+++ b/src/Makefile.windows
@@ -2,6 +2,9 @@
 
 product_name = oniguruma
 
+TEST_DIR = $(ONIG_DIR)/../test
+WIN_DIR  = $(ONIG_DIR)/../windows
+
 CPPFLAGS =
 CFLAGS = -O2 -nologo /W3
 LDFLAGS =
@@ -152,25 +155,24 @@ $(BUILD_DIR)/unicode_fold1_key.obj: $(ONIG_DIR)/unicode_fold1_key.c $(ONIG_DIR)/
 $(BUILD_DIR)/unicode_fold2_key.obj: $(ONIG_DIR)/unicode_fold2_key.c $(ONIG_DIR)/regenc.h $(BUILD_DIR)/config.h
 $(BUILD_DIR)/unicode_fold3_key.obj: $(ONIG_DIR)/unicode_fold3_key.c $(ONIG_DIR)/regenc.h $(BUILD_DIR)/config.h
 
-# C library test
-ctest: $(testc)
-	.\$(testc)
 
-# POSIX C library test
-ptest: $(testp)
-	.\$(testp)
+test_regset: $(TEST_DIR)/test_regset.c $(libname)
+	$(CC) -nologo /Fe:$@ /I. /I$(ONIG_DIR) /DONIG_EXTERN=extern /utf-8 $(TEST_DIR)/test_regset.c $(libname)
+
+test_utf8: $(TEST_DIR)/test_utf8.c $(libname)
+	$(CC) -nologo /Fe:$@ /I. /I$(ONIG_DIR) /DONIG_EXTERN=extern /utf-8 $(TEST_DIR)/test_utf8.c $(libname)
 
-$(testc): $(testc).c $(libname)
-	$(CC) -nologo /Fe:$(testc) -DONIG_EXTERN=extern $(testc).c $(libname)
+testc: $(WIN_DIR)/testc.c $(libname)
+	$(CC) -nologo /Fe:$@ /I. /I$(ONIG_DIR) /DONIG_EXTERN=extern $(WIN_DIR)/testc.c $(libname)
 
-$(testp): $(testc).c $(dlllib)
-	$(CC) -nologo -DPOSIX_TEST /Fe:$(testp) $(testc).c $(dlllib)
+testp: $(WIN_DIR)/testc.c $(libname)
+	$(CC) -nologo /Fe:$@ /I. /I$(ONIG_DIR) /DONIG_EXTERN=extern /DPOSIX_TEST $(WIN_DIR)/testc.c $(libname)
 
-$(testc)u: $(testc)u.c $(libname)
-	$(CC) -nologo /Fe:$(testc)u -DONIG_EXTERN=extern $(testc)u.c $(libname)
+testu: $(TEST_DIR)/testu.c $(libname)
+	$(CC) -nologo /Fe:$@ /I. /I$(ONIG_DIR) /DONIG_EXTERN=extern $(TEST_DIR)/testu.c $(libname)
 
 clean:
-	del $(BUILD_DIR)\*.obj $(BUILD_DIR)\*.lib $(BUILD_DIR)\*.exp $(BUILD_DIR)\*.dll $(BUILD_DIR)\$(testp).exe $(BUILD_DIR)\$(testc).exe $(BUILD_DIR)\$(testc).obj
+	del $(BUILD_DIR)\*.obj $(BUILD_DIR)\*.lib $(BUILD_DIR)\*.exp $(BUILD_DIR)\*.dll $(BUILD_DIR)\test_regset.exe $(BUILD_DIR)\test_utf8.exe $(BUILD_DIR)\testp.exe $(BUILD_DIR)\testc.exe $(BUILD_DIR)\testu.exe
 
 
 samples: all
diff --git a/src/ascii.c b/src/ascii.c
index e83e4d6..f2dc0d3 100644
--- a/src/ascii.c
+++ b/src/ascii.c
@@ -2,7 +2,7 @@
   ascii.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/big5.c b/src/big5.c
index ff8bd3b..79ae1e3 100644
--- a/src/big5.c
+++ b/src/big5.c
@@ -2,7 +2,7 @@
   big5.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,6 +55,16 @@ big5_mbc_enc_len(const UChar* p)
 }
 
 static int
+big5_code_to_mbclen(OnigCodePoint code)
+{
+  if ((code & (~0xffff)) != 0) return ONIGERR_INVALID_CODE_POINT_VALUE;
+  if ((code &    0xff00) != 0) return 2;
+  if (EncLen_BIG5[(int )(code & 0xff)] == 1) return 1;
+
+  return ONIGERR_INVALID_CODE_POINT_VALUE;
+}
+
+static int
 is_valid_mbc_string(const UChar* p, const UChar* end)
 {
   while (p < end) {
@@ -99,15 +109,6 @@ big5_mbc_case_fold(OnigCaseFoldType flag, const UChar** pp, const UChar* end,
                                    pp, end, lower);
 }
 
-#if 0
-static int
-big5_is_mbc_ambiguous(OnigCaseFoldType flag,
-                      const UChar** pp, const UChar* end)
-{
-  return onigenc_mbn_is_mbc_ambiguous(ONIG_ENCODING_BIG5, flag, pp, end);
-}
-#endif
-
 static int
 big5_is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
@@ -174,7 +175,7 @@ OnigEncodingType OnigEncodingBIG5 = {
   1,          /* min enc length */
   onigenc_is_mbc_newline_0x0a,
   big5_mbc_to_code,
-  onigenc_mb2_code_to_mbclen,
+  big5_code_to_mbclen,
   big5_code_to_mbc,
   big5_mbc_case_fold,
   onigenc_ascii_apply_all_case_fold,
diff --git a/src/config.h.win32 b/src/config.h.win32
index 1f848e2..82a35b9 100644
--- a/src/config.h.win32
+++ b/src/config.h.win32
@@ -1,3 +1,9 @@
+#if defined(__MINGW32__) || _MSC_VER >= 1600
+#define HAVE_STDINT_H 1
+#endif
+#if defined(__MINGW32__) || _MSC_VER >= 1800
+#define HAVE_INTTYPES_H 1
+#endif
 #define HAVE_SYS_TYPES_H 1
 #define HAVE_SYS_STAT_H 1
 #define HAVE_MEMORY_H 1
diff --git a/src/config.h.win64 b/src/config.h.win64
index f72671b..7f19699 100644
--- a/src/config.h.win64
+++ b/src/config.h.win64
@@ -1,3 +1,9 @@
+#if defined(__MINGW32__) || _MSC_VER >= 1600
+#define HAVE_STDINT_H 1
+#endif
+#if defined(__MINGW32__) || _MSC_VER >= 1800
+#define HAVE_INTTYPES_H 1
+#endif
 #define HAVE_SYS_TYPES_H 1
 #define HAVE_SYS_STAT_H 1
 #define HAVE_MEMORY_H 1
diff --git a/src/config.h.windows.in b/src/config.h.windows.in
index d8de1dd..d4f73d7 100644
--- a/src/config.h.windows.in
+++ b/src/config.h.windows.in
@@ -1,7 +1,14 @@
+#if defined(__MINGW32__) || _MSC_VER >= 1600
+#define HAVE_STDINT_H 1
+#endif
+#if defined(__MINGW32__) || _MSC_VER >= 1800
+#define HAVE_INTTYPES_H 1
+#endif
 #define HAVE_SYS_TYPES_H 1
 #define HAVE_SYS_STAT_H 1
 #define HAVE_MEMORY_H 1
 #define HAVE_OFF_T 1
+
 #define SIZEOF_INT 4
 #define SIZEOF_LONG 4
 #define SIZEOF_LONG_LONG 8
diff --git a/src/cp1251.c b/src/cp1251.c
index b4ce4d8..fa20780 100644
--- a/src/cp1251.c
+++ b/src/cp1251.c
@@ -2,8 +2,8 @@
   cp1251.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2006-2018  Byte      <byte AT mail DOT kna DOT ru>
- *                          K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2006-2019  Byte      <byte AT mail DOT kna DOT ru>
+ *                          K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/euc_jp.c b/src/euc_jp.c
index d17386d..640b3e3 100644
--- a/src/euc_jp.c
+++ b/src/euc_jp.c
@@ -2,7 +2,7 @@
   euc_jp.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -120,25 +120,6 @@ code_to_mbclen(OnigCodePoint code)
     return ONIGERR_INVALID_CODE_POINT_VALUE;
 }
 
-#if 0
-static int
-code_to_mbc_first(OnigCodePoint code)
-{
-  int first;
-
-  if ((code & 0xff0000) != 0) {
-    first = (code >> 16) & 0xff;
-  }
-  else if ((code & 0xff00) != 0) {
-    first = (code >> 8) & 0xff;
-  }
-  else {
-    return (int )code;
-  }
-  return first;
-}
-#endif
-
 static int
 code_to_mbc(OnigCodePoint code, UChar *buf)
 {
diff --git a/src/euc_jp_prop.c b/src/euc_jp_prop.c
index be719cf..a816f48 100644
--- a/src/euc_jp_prop.c
+++ b/src/euc_jp_prop.c
@@ -1,5 +1,5 @@
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -pt -T -L ANSI-C -N onigenc_euc_jp_lookup_property_name --output-file gperf1.tmp euc_jp_prop.gperf  */
+/* Command-line: gperf -pt -T -L ANSI-C -N onigenc_euc_jp_lookup_property_name --output-file gperf1.tmp euc_jp_prop.gperf  */
 /* Computed positions: -k'1,3' */
 
 #if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
diff --git a/src/euc_kr.c b/src/euc_kr.c
index bb968b0..7fa50af 100644
--- a/src/euc_kr.c
+++ b/src/euc_kr.c
@@ -2,7 +2,7 @@
   euc_kr.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,6 +55,16 @@ euckr_mbc_enc_len(const UChar* p)
 }
 
 static int
+euckr_code_to_mbclen(OnigCodePoint code)
+{
+  if ((code & (~0xffff)) != 0) return ONIGERR_INVALID_CODE_POINT_VALUE;
+  if ((code &    0xff00) != 0) return 2;
+  if (EncLen_EUCKR[(int )(code & 0xff)] == 1) return 1;
+
+  return ONIGERR_INVALID_CODE_POINT_VALUE;
+}
+
+static int
 is_valid_mbc_string(const UChar* p, const UChar* end)
 {
   while (p < end) {
@@ -98,15 +108,6 @@ euckr_mbc_case_fold(OnigCaseFoldType flag, const UChar** pp, const UChar* end,
                                    pp, end, lower);
 }
 
-#if 0
-static int
-euckr_is_mbc_ambiguous(OnigCaseFoldType flag,
-                       const UChar** pp, const UChar* end)
-{
-  return onigenc_mbn_is_mbc_ambiguous(ONIG_ENCODING_EUC_KR, flag, pp, end);
-}
-#endif
-
 static int
 euckr_is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
@@ -149,7 +150,7 @@ OnigEncodingType OnigEncodingEUC_KR = {
   1,          /* min enc length */
   onigenc_is_mbc_newline_0x0a,
   euckr_mbc_to_code,
-  onigenc_mb2_code_to_mbclen,
+  euckr_code_to_mbclen,
   euckr_code_to_mbc,
   euckr_mbc_case_fold,
   onigenc_ascii_apply_all_case_fold,
@@ -174,7 +175,7 @@ OnigEncodingType OnigEncodingEUC_CN = {
   1,          /* min enc length */
   onigenc_is_mbc_newline_0x0a,
   euckr_mbc_to_code,
-  onigenc_mb2_code_to_mbclen,
+  euckr_code_to_mbclen,
   euckr_code_to_mbc,
   euckr_mbc_case_fold,
   onigenc_ascii_apply_all_case_fold,
diff --git a/src/euc_tw.c b/src/euc_tw.c
index c9acaf1..8e72b97 100644
--- a/src/euc_tw.c
+++ b/src/euc_tw.c
@@ -2,7 +2,7 @@
   euc_tw.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,6 +55,20 @@ euctw_mbc_enc_len(const UChar* p)
 }
 
 static int
+euctw_code_to_mbclen(OnigCodePoint code)
+{
+       if ((code & 0xff000000) != 0) return 4;
+  else if ((code &   0xff0000) != 0) return ONIGERR_INVALID_CODE_POINT_VALUE;
+  else if ((code &     0xff00) != 0) return 2;
+  else {
+    if (EncLen_EUCTW[(int )(code & 0xff)] == 1)
+      return 1;
+
+    return ONIGERR_INVALID_CODE_POINT_VALUE;
+  }
+}
+
+static int
 is_valid_mbc_string(const UChar* p, const UChar* end)
 {
   while (p < end) {
@@ -155,7 +169,7 @@ OnigEncodingType OnigEncodingEUC_TW = {
   1,          /* min enc length */
   onigenc_is_mbc_newline_0x0a,
   euctw_mbc_to_code,
-  onigenc_mb4_code_to_mbclen,
+  euctw_code_to_mbclen,
   euctw_code_to_mbc,
   euctw_mbc_case_fold,
   onigenc_ascii_apply_all_case_fold,
diff --git a/src/gb18030.c b/src/gb18030.c
index 8d415b0..50898eb 100644
--- a/src/gb18030.c
+++ b/src/gb18030.c
@@ -3,7 +3,7 @@
 **********************************************************************/
 /*-
  * Copyright (c) 2005-2019  KUBO Takehiro <kubo AT jiubao DOT org>
- *                          K.Kosako <sndgk393 AT ybb DOT ne DOT jp>
+ *                          K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,7 @@
 #if 1
 #define DEBUG_GB18030(arg)
 #else
+#include <stdio.h>
 #define DEBUG_GB18030(arg) printf arg
 #endif
 
@@ -76,6 +77,20 @@ gb18030_mbc_enc_len(const UChar* p)
 }
 
 static int
+gb18030_code_to_mbclen(OnigCodePoint code)
+{
+       if ((code & 0xff000000) != 0) return 4;
+  else if ((code &   0xff0000) != 0) return ONIGERR_INVALID_CODE_POINT_VALUE;
+  else if ((code &     0xff00) != 0) return 2;
+  else {
+    if (GB18030_MAP[(int )(code & 0xff)] == CM)
+      return ONIGERR_INVALID_CODE_POINT_VALUE;
+
+    return 1;
+  }
+}
+
+static int
 is_valid_mbc_string(const UChar* p, const UChar* end)
 {
   while (p < end) {
@@ -135,15 +150,6 @@ gb18030_mbc_case_fold(OnigCaseFoldType flag, const UChar** pp, const UChar* end,
                                    pp, end, lower);
 }
 
-#if 0
-static int
-gb18030_is_mbc_ambiguous(OnigCaseFoldType flag,
-                         const UChar** pp, const UChar* end)
-{
-  return onigenc_mbn_is_mbc_ambiguous(ONIG_ENCODING_GB18030, flag, pp, end);
-}
-#endif
-
 static int
 gb18030_is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
@@ -522,7 +528,7 @@ OnigEncodingType OnigEncodingGB18030 = {
   1,          /* min enc length */
   onigenc_is_mbc_newline_0x0a,
   gb18030_mbc_to_code,
-  onigenc_mb4_code_to_mbclen,
+  gb18030_code_to_mbclen,
   gb18030_code_to_mbc,
   gb18030_mbc_case_fold,
   onigenc_ascii_apply_all_case_fold,
diff --git a/src/gperf_fold_key_conv.py b/src/gperf_fold_key_conv.py
index f453186..c633100 100755
--- a/src/gperf_fold_key_conv.py
+++ b/src/gperf_fold_key_conv.py
@@ -12,7 +12,7 @@ REG_STR_AT = re.compile('str\[(\d+)\]')
 REG_RETURN_TYPE = re.compile('^const\s+short\s+int\s*\*')
 REG_FOLD_KEY = re.compile('unicode_fold(\d)_key\s*\(register\s+const\s+char\s*\*\s*str,\s*register\s+size_t\s+len\)')
 REG_ENTRY = re.compile('\{".*?",\s*(-?\d+)\s*\}')
-REG_IF_LEN = re.compile('if\s*\(\s*len\s*<=\s*MAX_WORD_LENGTH.+')
+REG_IF_LEN = re.compile('\s*if\s*\(\s*len\s*<=\s*MAX_WORD_LENGTH.+')
 REG_GET_HASH = re.compile('(?:register\s+)?(?:unsigned\s+)?int\s+key\s*=\s*hash\s*\(str,\s*len\);')
 REG_GET_CODE = re.compile('(?:register\s+)?const\s+char\s*\*\s*s\s*=\s*wordlist\[key\]\.name;')
 REG_CODE_CHECK = re.compile('if\s*\(\*str\s*==\s*\*s\s*&&\s*!strncmp.+\)')
@@ -34,7 +34,7 @@ def parse_line(s, key_len):
     if r != s: return r
     r = re.sub(REG_ENTRY, '\\1', s)
     if r != s: return r
-    r = re.sub(REG_IF_LEN, 'if (0 == 0)', s)
+    r = re.sub(REG_IF_LEN, '', s)
     if r != s: return r
     r = re.sub(REG_GET_HASH, 'int key = hash(codes);', s)
     if r != s: return r
diff --git a/src/gperf_unfold_key_conv.py b/src/gperf_unfold_key_conv.py
index 3cf4836..d999d4e 100755
--- a/src/gperf_unfold_key_conv.py
+++ b/src/gperf_unfold_key_conv.py
@@ -12,7 +12,7 @@ REG_STR_AT = re.compile('str\[(\d+)\]')
 REG_UNFOLD_KEY = re.compile('onigenc_unicode_unfold_key\s*\(register\s+const\s+char\s*\*\s*str,\s*register\s+size_t\s+len\)')
 REG_ENTRY = re.compile('\{".+?",\s*/\*(.+?)\*/\s*(-?\d+),\s*(\d)\}')
 REG_EMPTY_ENTRY = re.compile('\{"",\s*(-?\d+),\s*(\d)\}')
-REG_IF_LEN = re.compile('if\s*\(\s*len\s*<=\s*MAX_WORD_LENGTH.+')
+REG_IF_LEN = re.compile('\s*if\s*\(\s*len\s*<=\s*MAX_WORD_LENGTH.+')
 REG_GET_HASH = re.compile('(?:register\s+)?(?:unsigned\s+)?int\s+key\s*=\s*hash\s*\(str,\s*len\);')
 REG_GET_CODE = re.compile('(?:register\s+)?const\s+char\s*\*\s*s\s*=\s*wordlist\[key\]\.name;')
 REG_CODE_CHECK = re.compile('if\s*\(\*str\s*==\s*\*s\s*&&\s*!strncmp.+\)')
@@ -32,7 +32,7 @@ def parse_line(s):
     if r != s: return r
     r = re.sub(REG_EMPTY_ENTRY, '{0xffffffff, \\1, \\2}', s)
     if r != s: return r
-    r = re.sub(REG_IF_LEN, 'if (0 == 0)', s)
+    r = re.sub(REG_IF_LEN, '', s)
     if r != s: return r
     r = re.sub(REG_GET_HASH, 'int key = hash(&code);', s)
     if r != s: return r
diff --git a/src/iso8859_1.c b/src/iso8859_1.c
index 3b64942..e681c2a 100644
--- a/src/iso8859_1.c
+++ b/src/iso8859_1.c
@@ -2,7 +2,7 @@
   iso8859_1.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -216,32 +216,6 @@ mbc_case_fold(OnigCaseFoldType flag, const UChar** pp,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_1_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    /* 0xdf, 0xaa, 0xb5, 0xba are lower case letter, but can't convert. */
-    if (*p >= 0xaa && *p <= 0xba)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_10.c b/src/iso8859_10.c
index f5882bc..e98cffb 100644
--- a/src/iso8859_10.c
+++ b/src/iso8859_10.c
@@ -2,7 +2,7 @@
   iso8859_10.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,28 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_10_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_11.c b/src/iso8859_11.c
index da8fda0..8639ce2 100644
--- a/src/iso8859_11.c
+++ b/src/iso8859_11.c
@@ -2,7 +2,7 @@
   iso8859_11.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/iso8859_13.c b/src/iso8859_13.c
index 0cf251c..2bd460f 100644
--- a/src/iso8859_13.c
+++ b/src/iso8859_13.c
@@ -2,7 +2,7 @@
   iso8859_13.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,32 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_13_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    /* 0xdf, 0xb5 are lower case letter, but can't convert. */
-    if (*p == 0xb5)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_14.c b/src/iso8859_14.c
index 030e9f5..5030b55 100644
--- a/src/iso8859_14.c
+++ b/src/iso8859_14.c
@@ -2,7 +2,7 @@
   iso8859_14.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,29 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1; /* return byte length of converted char to lower */
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag,
-                 const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_14_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_15.c b/src/iso8859_15.c
index 859d727..f32c3de 100644
--- a/src/iso8859_15.c
+++ b/src/iso8859_15.c
@@ -2,7 +2,7 @@
   iso8859_15.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,32 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1; /* return byte length of converted char to lower */
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_15_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    /* 0xdf etc.. are lower case letter, but can't convert. */
-    if (*p == 0xaa || *p == 0xb5 || *p == 0xba)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_16.c b/src/iso8859_16.c
index 2614e56..22a653a 100644
--- a/src/iso8859_16.c
+++ b/src/iso8859_16.c
@@ -2,7 +2,7 @@
   iso8859_16.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,28 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1; /* return byte length of converted char to lower */
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_16_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_2.c b/src/iso8859_2.c
index ba030d5..dc3d0a1 100644
--- a/src/iso8859_2.c
+++ b/src/iso8859_2.c
@@ -2,7 +2,7 @@
   iso8859_2.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,28 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1; /* return byte length of converted char to lower */
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_2_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static const OnigPairCaseFoldCodes CaseFoldMap[] = {
  { 0xa1, 0xb1 },
  { 0xa3, 0xb3 },
diff --git a/src/iso8859_3.c b/src/iso8859_3.c
index f090d0b..49dc6b2 100644
--- a/src/iso8859_3.c
+++ b/src/iso8859_3.c
@@ -2,7 +2,7 @@
   iso8859_3.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,32 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag, const UChar** pp,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_3_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    /* 0xaa, 0xb5, 0xba are lower case letter, but can't convert. */
-    if (*p == 0xb5)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_4.c b/src/iso8859_4.c
index 57dc9fe..f3f6ba9 100644
--- a/src/iso8859_4.c
+++ b/src/iso8859_4.c
@@ -2,7 +2,7 @@
   iso8859_4.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,31 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1; /* return byte length of converted char to lower */
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_4_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    if (*p == 0xa2)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_5.c b/src/iso8859_5.c
index a090d25..a5f587c 100644
--- a/src/iso8859_5.c
+++ b/src/iso8859_5.c
@@ -2,7 +2,7 @@
   iso8859_5.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -114,19 +114,6 @@ mbc_case_fold(OnigCaseFoldType flag ARG_UNUSED,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  (*pp)++;
-  v = (EncISO_8859_5_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_6.c b/src/iso8859_6.c
index 1c16c79..fb72442 100644
--- a/src/iso8859_6.c
+++ b/src/iso8859_6.c
@@ -2,7 +2,7 @@
   iso8859_6.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/iso8859_7.c b/src/iso8859_7.c
index 8c88351..018efac 100644
--- a/src/iso8859_7.c
+++ b/src/iso8859_7.c
@@ -2,7 +2,7 @@
   iso8859_7.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -114,26 +114,6 @@ mbc_case_fold(OnigCaseFoldType flag ARG_UNUSED,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  (*pp)++;
-  v = (EncISO_8859_7_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    if (*p == 0xc0 || *p == 0xe0)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/iso8859_8.c b/src/iso8859_8.c
index bd3e94d..92a5eb1 100644
--- a/src/iso8859_8.c
+++ b/src/iso8859_8.c
@@ -2,7 +2,7 @@
   iso8859_8.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/iso8859_9.c b/src/iso8859_9.c
index 1d291d5..1f9bdea 100644
--- a/src/iso8859_9.c
+++ b/src/iso8859_9.c
@@ -2,7 +2,7 @@
   iso8859_9.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,32 +121,6 @@ mbc_case_fold(OnigCaseFoldType flag,
   return 1;
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-    (*pp)++;
-    return TRUE;
-  }
-
-  (*pp)++;
-  v = (EncISO_8859_9_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  if ((v | BIT_CTYPE_LOWER) != 0) {
-    /* 0xdf etc..  are lower case letter, but can't convert. */
-    if (*p >= 0xaa && *p <= 0xba)
-      return FALSE;
-    else
-      return TRUE;
-  }
-
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/koi8.c b/src/koi8.c
index 94c95a0..37023c6 100644
--- a/src/koi8.c
+++ b/src/koi8.c
@@ -2,7 +2,7 @@
   koi8.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -115,25 +115,6 @@ koi8_mbc_case_fold(OnigCaseFoldType flag ARG_UNUSED,
   return 1;
 }
 
-#if 0
-static int
-koi8_is_mbc_ambiguous(OnigAmbigType flag, const OnigUChar** pp, const OnigUChar* end)
-{
-  const OnigUChar* p = *pp;
-
-  (*pp)++;
-  if (((flag & ONIGENC_CASE_FOLD_ASCII_CASE) != 0 &&
-       ONIGENC_IS_MBC_ASCII(p)) ||
-      ((flag & ONIGENC_CASE_FOLD_NONASCII_CASE) != 0 &&
-       !ONIGENC_IS_MBC_ASCII(p))) {
-    int v = (EncKOI8_CtypeTable[*p] &
-             (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-    return (v != 0 ? TRUE : FALSE);
-  }
-  return FALSE;
-}
-#endif
-
 static int
 koi8_is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/koi8_r.c b/src/koi8_r.c
index 1284f7f..c77302f 100644
--- a/src/koi8_r.c
+++ b/src/koi8_r.c
@@ -2,7 +2,7 @@
   koi8_r.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -114,19 +114,6 @@ koi8_r_mbc_case_fold(OnigCaseFoldType flag ARG_UNUSED,
   return 1;
 }
 
-#if 0
-static int
-koi8_r_is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  int v;
-  const UChar* p = *pp;
-
-  (*pp)++;
-  v = (EncKOI8_R_CtypeTable[*p] & (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-  return (v != 0 ? TRUE : FALSE);
-}
-#endif
-
 static int
 koi8_r_is_code_ctype(OnigCodePoint code, unsigned int ctype)
 {
diff --git a/src/make_property.sh b/src/make_property.sh
index bc5cf98..cef0a96 100755
--- a/src/make_property.sh
+++ b/src/make_property.sh
@@ -1,8 +1,9 @@
 #!/bin/sh
 
+GPERF=gperf
+
 TMP1=gperf1.tmp
 TMP2=gperf2.tmp
-GPERF=/usr/local/bin/gperf
 
 GPERF_OPT='-pt -T -L ANSI-C'
 
diff --git a/src/make_unicode_egcb_data.py b/src/make_unicode_egcb_data.py
index 0f63f97..9c71796 100755
--- a/src/make_unicode_egcb_data.py
+++ b/src/make_unicode_egcb_data.py
@@ -1,7 +1,7 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 # make_unicode_egcb_data.py
-# Copyright (c) 2017-2018  K.Kosako
+# Copyright (c) 2017-2019  K.Kosako
 
 import sys
 import re
@@ -13,18 +13,19 @@ PR_LINE_REG  = re.compile("([0-9A-Fa-f]+)(?:..([0-9A-Fa-f]+))?\s*;\s*(\w+)")
 PA_LINE_REG  = re.compile("(\w+)\s*;\s*(\w+)")
 PVA_LINE_REG = re.compile("(sc|gc)\s*;\s*(\w+)\s*;\s*(\w+)(?:\s*;\s*(\w+))?")
 BL_LINE_REG  = re.compile("([0-9A-Fa-f]+)\.\.([0-9A-Fa-f]+)\s*;\s*(.*)")
-VERSION_REG  = re.compile("#\s*.*-(\d+\.\d+\.\d+)\.txt")
+VERSION_REG  = re.compile("#\s*.*-(\d+)\.(\d+)\.(\d+)\.txt")
 
-VERSION_INFO = None
+VERSION_INFO = [-1, -1, -1]
 DIC  = { }
 PROPS = []
 PropIndex = { }
 
 def check_version_info(s):
-  global VERSION_INFO
   m = VERSION_REG.match(s)
   if m is not None:
-    VERSION_INFO = m.group(1)
+    VERSION_INFO[0] = int(m.group(1))
+    VERSION_INFO[1] = int(m.group(2))
+    VERSION_INFO[2] = int(m.group(3))
 
 def print_ranges(ranges):
   for (start, end) in ranges:
@@ -160,7 +161,7 @@ def parse_properties(path):
         continue
 
       if s[0] == '#':
-        if VERSION_INFO is None:
+        if VERSION_INFO[0] < 0:
           check_version_info(s)
 
       m = PR_LINE_REG.match(s)
@@ -194,7 +195,7 @@ PROPS = sorted(PROPS)
 print '/* unicode_egcb_data.c: Generated by make_unicode_egcb_data.py. */'
 COPYRIGHT = '''
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -222,9 +223,11 @@ COPYRIGHT = '''
 
 print COPYRIGHT
 print ''
-if VERSION_INFO is not None:
-  print "#define GRAPHEME_BREAK_PROPERTY_VERSION  %s" % re.sub(r'[\.-]', '_', VERSION_INFO)
-  print ''
+if VERSION_INFO[0] < 0:
+  raise RuntimeError("Version is not found")
+
+print "#define GRAPHEME_BREAK_PROPERTY_VERSION  %02d%02d%02d" % (VERSION_INFO[0], VERSION_INFO[1], VERSION_INFO[2])
+print ''
 
 ranges = []
 for prop in PROPS:
diff --git a/src/make_unicode_fold.sh b/src/make_unicode_fold.sh
index 35ce974..1d5cc1e 100755
--- a/src/make_unicode_fold.sh
+++ b/src/make_unicode_fold.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-GPERF=/usr/local/bin/gperf
+GPERF=gperf
 
 TMP0=gperf0.tmp
 TMP1=gperf1.tmp
diff --git a/src/make_unicode_fold_data.py b/src/make_unicode_fold_data.py
index 783988c..55d5b88 100755
--- a/src/make_unicode_fold_data.py
+++ b/src/make_unicode_fold_data.py
@@ -1,7 +1,7 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 # make_unicode_fold_data.py
-# Copyright (c) 2016-2018  K.Kosako
+# Copyright (c) 2016-2019  K.Kosako
 
 import sys
 import re
@@ -16,9 +16,9 @@ DataName = 'OnigUnicodeFolds'
 ENCODING = 'utf-8'
 
 LINE_REG = re.compile("([0-9A-F]{1,6}); (.); ([0-9A-F]{1,6})(?: ([0-9A-F]{1,6}))?(?: ([0-9A-F]{1,6}))?;(?:\s*#\s*)(.*)")
-VERSION_REG  = re.compile("#.*-(\d+\.\d+\.\d+)\.txt")
+VERSION_REG  = re.compile("#.*-(\d+)\.(\d+)\.(\d+)\.txt")
 
-VERSION_INFO = None
+VERSION_INFO = [-1, -1, -1]
 
 FOLDS = {}
 TURKISH_FOLDS = {}
@@ -56,18 +56,19 @@ def form3bytes(x):
     return "\\x%02x\\x%02x\\x%02x" % (x2, x1, x0)
 
 def check_version_info(s):
-    global VERSION_INFO
-    if VERSION_INFO is None:
-        m = VERSION_REG.match(s)
-        if m is not None:
-            VERSION_INFO = m.group(1)
+  m = VERSION_REG.match(s)
+  if m is not None:
+    VERSION_INFO[0] = int(m.group(1))
+    VERSION_INFO[1] = int(m.group(2))
+    VERSION_INFO[2] = int(m.group(3))
 
 def parse_line(s):
     if len(s) == 0:
-        return False
+      return False
     if s[0] == '#':
+      if VERSION_INFO[0] < 0:
         check_version_info(s)
-        return False
+      return False
 
     m = LINE_REG.match(s)
     if m is None:
@@ -232,9 +233,11 @@ def output_fold_source(f, out_comment):
     print >> f, "/* This file was generated by make_unicode_fold_data.py. */"
     print >> f, '#include "regenc.h"'
     print >> f, ''
-    if VERSION_INFO is not None:
-        print "#define UNICODE_CASEFOLD_VERSION  %s" % re.sub(r'[\.-]', '_', VERSION_INFO)
-        print ''
+    if VERSION_INFO[0] < 0:
+      raise RuntimeError("Version is not found")
+
+    print "#define UNICODE_CASEFOLD_VERSION  %02d%02d%02d" % (VERSION_INFO[0], VERSION_INFO[1], VERSION_INFO[2])
+    print ''
     #output_macros(f, DataName)
     print >> f, ''
     #output_typedef(f)
@@ -246,7 +249,7 @@ HEAD = '''
 /* This gperf source file was generated by make_unicode_fold_data.py */
 
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/make_unicode_property.sh b/src/make_unicode_property.sh
index 124d76a..51c8951 100755
--- a/src/make_unicode_property.sh
+++ b/src/make_unicode_property.sh
@@ -1,10 +1,11 @@
 #!/bin/sh
 
+GPERF=gperf
+
 NAME=unicode_property_data
 TMP1=gperf1.tmp
 TMP2=gperf2.tmp
 TMP=
-GPERF=/usr/local/bin/gperf
 
 GPERF_OPT='-T -C -c -t -j1 -L ANSI-C --ignore-case --pic -Q unicode_prop_name_pool'
 POOL_CAST='s/\(int *\)\(size_t *\)&\(\(struct +unicode_prop_name_pool_t *\* *\) *0\)->unicode_prop_name_pool_str([^,]+)/pool_offset(\1)/g'
diff --git a/src/make_unicode_property_data.py b/src/make_unicode_property_data.py
index dc3071a..9776628 100755
--- a/src/make_unicode_property_data.py
+++ b/src/make_unicode_property_data.py
@@ -1,7 +1,7 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 # make_unicode_property_data.py
-# Copyright (c) 2016-2018  K.Kosako
+# Copyright (c) 2016-2019  K.Kosako
 
 import sys
 import re
@@ -22,9 +22,12 @@ PR_LINE_REG  = re.compile("([0-9A-Fa-f]+)(?:..([0-9A-Fa-f]+))?\s*;\s*(\w+)")
 PA_LINE_REG  = re.compile("(\w+)\s*;\s*(\w+)")
 PVA_LINE_REG = re.compile("(sc|gc)\s*;\s*(\w+)\s*;\s*(\w+)(?:\s*;\s*(\w+))?")
 BL_LINE_REG  = re.compile("([0-9A-Fa-f]+)\.\.([0-9A-Fa-f]+)\s*;\s*(.*)")
-VERSION_REG  = re.compile("#\s*.*-(\d+\.\d+\.\d+)\.txt")
+UNICODE_VERSION_REG = re.compile("#\s*.*-(\d+)\.(\d+)\.(\d+)\.txt")
+EMOJI_VERSION_REG   = re.compile("(?i)#\s*Version:\s*(\d+)\.(\d+)")
+
+VERSION_INFO = [-1, -1, -1]
+EMOJI_VERSION_INFO = [-1, -1]
 
-VERSION_INFO = None
 DIC  = { }
 KDIC = { }
 PropIndex = { }
@@ -40,13 +43,6 @@ def fix_block_name(name):
   s = re.sub(r'[- ]+', '_', name)
   return 'In_' + s
 
-def check_version_info(s):
-  global VERSION_INFO
-  m = VERSION_REG.match(s)
-  if m is not None:
-    VERSION_INFO = m.group(1)
-
-
 def print_ranges(ranges):
   for (start, end) in ranges:
     print "0x%06x, 0x%06x" % (start, end)
@@ -233,7 +229,8 @@ def parse_unicode_data_file(f):
   normalize_ranges_in_dic(dic)
   return dic, assigned
 
-def parse_properties(path, klass, prop_prefix = None):
+def parse_properties(path, klass, prop_prefix = None, version_reg = None):
+  version_match = None
   with open(path, 'r') as f:
     dic = { }
     prop = None
@@ -243,9 +240,10 @@ def parse_properties(path, klass, prop_prefix = None):
       if len(s) == 0:
         continue
 
-      if s[0] == '#':
-        if VERSION_INFO is None:
-          check_version_info(s)
+      if s[0] == '#' and version_reg is not None and version_match is None:
+        version_match = version_reg.match(s)
+        if version_match is not None:
+          continue
 
       m = PR_LINE_REG.match(s)
       if m:
@@ -266,7 +264,7 @@ def parse_properties(path, klass, prop_prefix = None):
         props.append(prop)
 
   normalize_ranges_in_dic(dic)
-  return (dic, props)
+  return (dic, props, version_match)
 
 def parse_property_aliases(path):
   a = { }
@@ -414,11 +412,11 @@ def entry_and_print_prop_and_index(name, index):
   nname = normalize_prop_name(name)
   print_prop_and_index(nname, index)
 
-def parse_and_merge_properties(path, klass):
-  dic, props = parse_properties(path, klass)
+def parse_and_merge_properties(path, klass, prop_prefix = None, version_reg = None):
+  dic, props, ver_m = parse_properties(path, klass, prop_prefix, version_reg)
   merge_dic(DIC, dic)
   merge_props(PROPS, props)
-  return dic, props
+  return dic, props, ver_m
 
 ### main ###
 argv = sys.argv
@@ -447,11 +445,21 @@ with open('UnicodeData.txt', 'r') as f:
 PROPS = DIC.keys()
 PROPS = list_sub(PROPS, POSIX_LIST)
 
-parse_and_merge_properties('DerivedCoreProperties.txt', 'Derived Property')
-dic, props = parse_and_merge_properties('Scripts.txt', 'Script')
+_, _, ver_m = parse_and_merge_properties('DerivedCoreProperties.txt', 'Derived Property', None, UNICODE_VERSION_REG)
+if ver_m is not None:
+  VERSION_INFO[0] = int(ver_m.group(1))
+  VERSION_INFO[1] = int(ver_m.group(2))
+  VERSION_INFO[2] = int(ver_m.group(3))
+
+dic, props, _ = parse_and_merge_properties('Scripts.txt', 'Script')
 DIC['Unknown'] = inverse_ranges(add_ranges_in_dic(dic))
+
 parse_and_merge_properties('PropList.txt',   'Binary Property')
-parse_and_merge_properties('emoji-data.txt', 'Emoji Property')
+
+_, _, ver_m = parse_and_merge_properties('emoji-data.txt', 'Emoji Property', None, EMOJI_VERSION_REG)
+if ver_m is not None:
+  EMOJI_VERSION_INFO[0] = int(ver_m.group(1))
+  EMOJI_VERSION_INFO[1] = int(ver_m.group(2))
 
 PROPS.append('Unknown')
 KDIC['Unknown'] = 'Script'
@@ -464,9 +472,9 @@ dic, BLOCKS = parse_blocks('Blocks.txt')
 merge_dic(DIC, dic)
 
 if INCLUDE_GRAPHEME_CLUSTER_DATA:
-  dic, props = parse_properties('GraphemeBreakProperty.txt',
-                                'GraphemeBreak Property',
-                                GRAPHEME_CLUSTER_BREAK_NAME_PREFIX)
+  dic, props, _ = parse_properties('GraphemeBreakProperty.txt',
+                                   'GraphemeBreak Property',
+                                   GRAPHEME_CLUSTER_BREAK_NAME_PREFIX)
   merge_dic(DIC, dic)
   merge_props(PROPS, props)
   #prop = GRAPHEME_CLUSTER_BREAK_NAME_PREFIX + 'Other'
@@ -533,9 +541,13 @@ sys.stdout.write(s)
 
 if OUTPUT_LIST_MODE:
   UPF = open("UNICODE_PROPERTIES", "w")
-  if VERSION_INFO is not None:
-    print >> UPF, "Unicode Properties (from Unicode Version: %s)" % VERSION_INFO
-    print >> UPF, ''
+  if VERSION_INFO[0] < 0:
+    raise RuntimeError("Unicode Version is not found")
+  if EMOJI_VERSION_INFO[0] < 0:
+    raise RuntimeError("Emoji Version is not found")
+
+  print >> UPF, "Unicode Properties (Unicode Version: %d.%d.%d,  Emoji: %d.%d)" % (VERSION_INFO[0], VERSION_INFO[1], VERSION_INFO[2], EMOJI_VERSION_INFO[0], EMOJI_VERSION_INFO[1])
+  print >> UPF, ''
 
 index = -1
 for prop in POSIX_LIST:
@@ -569,9 +581,14 @@ if not(POSIX_ONLY):
 print '%%'
 print ''
 if not(POSIX_ONLY):
-  if VERSION_INFO is not None:
-    print "#define UNICODE_PROPERTY_VERSION  %s" % re.sub(r'[\.-]', '_', VERSION_INFO)
-    print ''
+  if VERSION_INFO[0] < 0:
+    raise RuntimeError("Unicode Version is not found")
+  if EMOJI_VERSION_INFO[0] < 0:
+    raise RuntimeError("Emoji Version is not found")
+
+  print "#define UNICODE_PROPERTY_VERSION  %02d%02d%02d" % (VERSION_INFO[0], VERSION_INFO[1], VERSION_INFO[2])
+  print "#define UNICODE_EMOJI_VERSION     %02d%02d" % (EMOJI_VERSION_INFO[0], EMOJI_VERSION_INFO[1])
+  print ''
 
 print "#define PROPERTY_NAME_MAX_SIZE  %d" % (PROPERTY_NAME_MAX_LEN + 10)
 print "#define CODE_RANGES_NUM         %d" % (index + 1)
diff --git a/src/make_unicode_wb_data.py b/src/make_unicode_wb_data.py
index 624fa7e..ddedd5d 100755
--- a/src/make_unicode_wb_data.py
+++ b/src/make_unicode_wb_data.py
@@ -13,18 +13,19 @@ PR_LINE_REG  = re.compile("([0-9A-Fa-f]+)(?:..([0-9A-Fa-f]+))?\s*;\s*(\w+)")
 PA_LINE_REG  = re.compile("(\w+)\s*;\s*(\w+)")
 PVA_LINE_REG = re.compile("(sc|gc)\s*;\s*(\w+)\s*;\s*(\w+)(?:\s*;\s*(\w+))?")
 BL_LINE_REG  = re.compile("([0-9A-Fa-f]+)\.\.([0-9A-Fa-f]+)\s*;\s*(.*)")
-VERSION_REG  = re.compile("#\s*.*-(\d+\.\d+\.\d+)\.txt")
+VERSION_REG  = re.compile("#\s*.*-(\d+)\.(\d+)\.(\d+)\.txt")
 
-VERSION_INFO = None
+VERSION_INFO = [-1, -1, -1]
 DIC  = { }
 PROPS = []
 PropIndex = { }
 
 def check_version_info(s):
-  global VERSION_INFO
   m = VERSION_REG.match(s)
   if m is not None:
-    VERSION_INFO = m.group(1)
+    VERSION_INFO[0] = int(m.group(1))
+    VERSION_INFO[1] = int(m.group(2))
+    VERSION_INFO[2] = int(m.group(3))
 
 def print_ranges(ranges):
   for (start, end) in ranges:
@@ -160,7 +161,7 @@ def parse_properties(path):
         continue
 
       if s[0] == '#':
-        if VERSION_INFO is None:
+        if VERSION_INFO[0] < 0:
           check_version_info(s)
 
       m = PR_LINE_REG.match(s)
@@ -194,7 +195,7 @@ PROPS = sorted(PROPS)
 print '/* unicode_wb_data.c: Generated by make_unicode_wb_data.py. */'
 COPYRIGHT = '''
 /*-
- * Copyright (c) 2019  K.Kosako  <kkosako0 AT gmail DOT com>
+ * Copyright (c) 2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -222,9 +223,11 @@ COPYRIGHT = '''
 
 print COPYRIGHT
 print ''
-if VERSION_INFO is not None:
-  print "#define WORD_BREAK_PROPERTY_VERSION  %s" % re.sub(r'[\.-]', '_', VERSION_INFO)
-  print ''
+if VERSION_INFO[0] < 0:
+  raise RuntimeError("Version is not found.")
+
+print "#define WORD_BREAK_PROPERTY_VERSION  %02d%02d%02d" % (VERSION_INFO[0], VERSION_INFO[1], VERSION_INFO[2])
+print ''
 
 ranges = []
 for prop in PROPS:
diff --git a/src/mktable.c b/src/mktable.c
index 80ac08a..318bac0 100644
--- a/src/mktable.c
+++ b/src/mktable.c
@@ -2,7 +2,7 @@
   mktable.c
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/onig_init.c b/src/onig_init.c
index 7ad98b7..c660e7d 100644
--- a/src/onig_init.c
+++ b/src/onig_init.c
@@ -2,7 +2,7 @@
   onig_init.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2016-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2016-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/oniggnu.h b/src/oniggnu.h
index d688883..96d9085 100644
--- a/src/oniggnu.h
+++ b/src/oniggnu.h
@@ -4,7 +4,7 @@
   oniggnu.h - Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2005  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/onigposix.h b/src/onigposix.h
index da0f919..5ff779f 100644
--- a/src/onigposix.h
+++ b/src/onigposix.h
@@ -4,7 +4,7 @@
   onigposix.h - Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -95,6 +95,7 @@ typedef struct {
 #endif
 #endif
 
+#ifndef ONIG_STATIC
 #ifndef ONIG_EXTERN
 #if defined(_WIN32) && !defined(__GNUC__)
 #if defined(ONIGURUMA_EXPORT)
@@ -108,6 +109,9 @@ typedef struct {
 #ifndef ONIG_EXTERN
 #define ONIG_EXTERN   extern
 #endif
+#else
+#define ONIG_EXTERN   extern
+#endif
 
 #ifndef ONIGURUMA_H
 typedef unsigned int        OnigOptionType;
diff --git a/src/oniguruma.h b/src/oniguruma.h
index 90cf2d9..08ac6f7 100644
--- a/src/oniguruma.h
+++ b/src/oniguruma.h
@@ -4,7 +4,7 @@
   oniguruma.h - Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,9 +36,9 @@ extern "C" {
 #define ONIGURUMA
 #define ONIGURUMA_VERSION_MAJOR   6
 #define ONIGURUMA_VERSION_MINOR   9
-#define ONIGURUMA_VERSION_TEENY   3
+#define ONIGURUMA_VERSION_TEENY   4
 
-#define ONIGURUMA_VERSION_INT     60903
+#define ONIGURUMA_VERSION_INT     60904
 
 #ifndef P_
 #if defined(__STDC__) || defined(_WIN32)
@@ -687,6 +687,14 @@ typedef OnigRegexType*  OnigRegex;
   typedef OnigRegexType  regex_t;
 #endif
 
+struct OnigRegSetStruct;
+typedef struct OnigRegSetStruct OnigRegSet;
+
+typedef enum {
+  ONIG_REGSET_POSITION_LEAD = 0,
+  ONIG_REGSET_REGEX_LEAD    = 1,
+  ONIG_REGSET_PRIORITY_TO_REGEX_ORDER = 2
+} OnigRegSetLead;
 
 typedef struct {
   int             num_of_elements;
@@ -797,6 +805,26 @@ ONIG_EXTERN
 int onig_match P_((OnigRegex, const OnigUChar* str, const OnigUChar* end, const OnigUChar* at, OnigRegion* region, OnigOptionType option));
 ONIG_EXTERN
 int onig_match_with_param P_((OnigRegex, const OnigUChar* str, const OnigUChar* end, const OnigUChar* at, OnigRegion* region, OnigOptionType option, OnigMatchParam* mp));
+
+ONIG_EXTERN
+int onig_regset_new P_((OnigRegSet** rset, int n, regex_t* regs[]));
+ONIG_EXTERN
+int onig_regset_add P_((OnigRegSet* set, regex_t* reg));
+ONIG_EXTERN
+int onig_regset_replace P_((OnigRegSet* set, int at, regex_t* reg));
+ONIG_EXTERN
+void onig_regset_free P_((OnigRegSet* set));
+ONIG_EXTERN
+int onig_regset_number_of_regex P_((OnigRegSet* set));
+ONIG_EXTERN
+regex_t* onig_regset_get_regex P_((OnigRegSet* set, int at));
+ONIG_EXTERN
+OnigRegion* onig_regset_get_region P_((OnigRegSet* set, int at));
+ONIG_EXTERN
+int onig_regset_search P_((OnigRegSet* set, const OnigUChar* str, const OnigUChar* end, const OnigUChar* start, const OnigUChar* range, OnigRegSetLead lead, OnigOptionType option, int* rmatch_pos));
+ONIG_EXTERN
+int onig_regset_search_with_param P_((OnigRegSet* set, const OnigUChar* str, const OnigUChar* end, const OnigUChar* start, const OnigUChar* range,  OnigRegSetLead lead, OnigOptionType option, OnigMatchParam* mps[], int* rmatch_pos));
+
 ONIG_EXTERN
 OnigRegion* onig_region_new P_((void));
 ONIG_EXTERN
diff --git a/src/regcomp.c b/src/regcomp.c
index b96c793..69d4b95 100644
--- a/src/regcomp.c
+++ b/src/regcomp.c
@@ -2,7 +2,7 @@
   regcomp.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -224,17 +224,17 @@ ops_free(regex_t* reg)
 #endif
 
     switch (opcode) {
-    case OP_EXACTMBN:
+    case OP_STR_MBN:
       if (! is_in_string_pool(reg, op->exact_len_n.s))
         xfree(op->exact_len_n.s);
       break;
-    case OP_EXACTN: case OP_EXACTMB2N: case OP_EXACTMB3N: case OP_EXACTN_IC:
+    case OP_STR_N: case OP_STR_MB2N: case OP_STR_MB3N: case OP_STR_N_IC:
       if (! is_in_string_pool(reg, op->exact_n.s))
         xfree(op->exact_n.s);
       break;
-    case OP_EXACT1: case OP_EXACT2: case OP_EXACT3: case OP_EXACT4:
-    case OP_EXACT5: case OP_EXACTMB2N1: case OP_EXACTMB2N2:
-    case OP_EXACTMB2N3: case OP_EXACT1_IC:
+    case OP_STR_1: case OP_STR_2: case OP_STR_3: case OP_STR_4:
+    case OP_STR_5: case OP_STR_MB2N1: case OP_STR_MB2N2:
+    case OP_STR_MB2N3: case OP_STR_1_IC:
       break;
 
     case OP_CCLASS_NOT: case OP_CCLASS:
@@ -298,17 +298,17 @@ ops_calc_size_of_string_pool(regex_t* reg)
 #endif
 
     switch (opcode) {
-    case OP_EXACTMBN:
+    case OP_STR_MBN:
       total += op->exact_len_n.len * op->exact_len_n.n;
       break;
-    case OP_EXACTN:
-    case OP_EXACTN_IC:
+    case OP_STR_N:
+    case OP_STR_N_IC:
       total += op->exact_n.n;
       break;
-    case OP_EXACTMB2N:
+    case OP_STR_MB2N:
       total += op->exact_n.n * 2;
       break;
-    case OP_EXACTMB3N:
+    case OP_STR_MB3N:
       total += op->exact_n.n * 3;
       break;
 
@@ -349,15 +349,15 @@ ops_make_string_pool(regex_t* reg)
 #endif
 
     switch (opcode) {
-    case OP_EXACTMBN:
+    case OP_STR_MBN:
       len = op->exact_len_n.len * op->exact_len_n.n;
       xmemcpy(curr, op->exact_len_n.s, len);
       xfree(op->exact_len_n.s);
       op->exact_len_n.s = curr;
       curr += len;
       break;
-    case OP_EXACTN:
-    case OP_EXACTN_IC:
+    case OP_STR_N:
+    case OP_STR_N_IC:
       len = op->exact_n.n;
     copy:
       xmemcpy(curr, op->exact_n.s, len);
@@ -365,11 +365,11 @@ ops_make_string_pool(regex_t* reg)
       op->exact_n.s = curr;
       curr += len;
       break;
-    case OP_EXACTMB2N:
+    case OP_STR_MB2N:
       len = op->exact_n.n * 2;
       goto copy;
       break;
-    case OP_EXACTMB3N:
+    case OP_STR_MB3N:
       len = op->exact_n.n * 3;
       goto copy;
       break;
@@ -427,7 +427,7 @@ onig_positive_int_multiply(int x, int y)
 
 
 static void
-swap_node(Node* a, Node* b)
+node_swap(Node* a, Node* b)
 {
   Node c;
 
@@ -452,6 +452,81 @@ swap_node(Node* a, Node* b)
   }
 }
 
+static int
+node_list_len(Node* list)
+{
+  int len;
+
+  len = 1;
+  while (IS_NOT_NULL(NODE_CDR(list))) {
+    list = NODE_CDR(list);
+    len++;
+  }
+
+  return len;
+}
+
+static Node*
+node_list_add(Node* list, Node* x)
+{
+  Node *n;
+
+  n = onig_node_new_list(x, NULL);
+  if (IS_NULL(n)) return NULL_NODE;
+
+  if (IS_NOT_NULL(list)) {
+    while (IS_NOT_NULL(NODE_CDR(list)))
+      list = NODE_CDR(list);
+
+    NODE_CDR(list) = n;
+  }
+
+  return n;
+}
+
+static int
+node_str_node_cat(Node* node, Node* add)
+{
+  int r;
+
+  if (STR_(node)->flag != STR_(add)->flag)
+    return ONIGERR_TYPE_BUG;
+
+  r = onig_node_str_cat(node, STR_(add)->s, STR_(add)->end);
+  if (r != 0) return r;
+
+  if (NODE_STRING_IS_CASE_FOLD_MATCH(node))
+    STR_(node)->case_min_len += STR_(add)->case_min_len;
+
+  return 0;
+}
+
+static int
+node_str_cat_case_fold(Node* node, const UChar* s, const UChar* end, int case_min_len)
+{
+  int r;
+
+  if (! NODE_STRING_IS_CASE_FOLD_MATCH(node))
+    return ONIGERR_TYPE_BUG;
+
+  r = onig_node_str_cat(node, s, end);
+  if (r != 0) return r;
+
+  STR_(node)->case_min_len += case_min_len;
+  return 0;
+}
+
+static void
+node_conv_to_str_node(Node* node, int flag)
+{
+  NODE_SET_TYPE(node, NODE_STRING);
+  STR_(node)->flag     = flag;
+  STR_(node)->s        = STR_(node)->buf;
+  STR_(node)->end      = STR_(node)->buf;
+  STR_(node)->capacity = 0;
+  STR_(node)->case_min_len = 0;
+}
+
 static OnigLen
 distance_add(OnigLen d1, OnigLen d2)
 {
@@ -549,52 +624,45 @@ static int compile_length_tree(Node* node, regex_t* reg);
 static int compile_tree(Node* node, regex_t* reg, ScanEnv* env);
 
 
-#define IS_NEED_STR_LEN_OP_EXACT(op) \
-   ((op) == OP_EXACTN    || (op) == OP_EXACTMB2N ||\
-    (op) == OP_EXACTMB3N || (op) == OP_EXACTMBN  || (op) == OP_EXACTN_IC)
+#define IS_NEED_STR_LEN_OP(op) \
+   ((op) == OP_STR_N    || (op) == OP_STR_MB2N ||\
+    (op) == OP_STR_MB3N || (op) == OP_STR_MBN  || (op) == OP_STR_N_IC)
 
 static int
-select_str_opcode(int mb_len, int str_len, int ignore_case)
+select_str_opcode(int mb_len, int str_len)
 {
   int op;
 
-  if (ignore_case) {
+  switch (mb_len) {
+  case 1:
     switch (str_len) {
-    case 1:  op = OP_EXACT1_IC; break;
-    default: op = OP_EXACTN_IC; break;
+    case 1:  op = OP_STR_1; break;
+    case 2:  op = OP_STR_2; break;
+    case 3:  op = OP_STR_3; break;
+    case 4:  op = OP_STR_4; break;
+    case 5:  op = OP_STR_5; break;
+    default: op = OP_STR_N; break;
     }
-  }
-  else {
-    switch (mb_len) {
-    case 1:
-      switch (str_len) {
-      case 1:  op = OP_EXACT1; break;
-      case 2:  op = OP_EXACT2; break;
-      case 3:  op = OP_EXACT3; break;
-      case 4:  op = OP_EXACT4; break;
-      case 5:  op = OP_EXACT5; break;
-      default: op = OP_EXACTN; break;
-      }
-      break;
+    break;
 
-    case 2:
-      switch (str_len) {
-      case 1:  op = OP_EXACTMB2N1; break;
-      case 2:  op = OP_EXACTMB2N2; break;
-      case 3:  op = OP_EXACTMB2N3; break;
-      default: op = OP_EXACTMB2N;  break;
-      }
-      break;
+  case 2:
+    switch (str_len) {
+    case 1:  op = OP_STR_MB2N1; break;
+    case 2:  op = OP_STR_MB2N2; break;
+    case 3:  op = OP_STR_MB2N3; break;
+    default: op = OP_STR_MB2N;  break;
+    }
+    break;
 
-    case 3:
-      op = OP_EXACTMB3N;
-      break;
+  case 3:
+    op = OP_STR_MB3N;
+    break;
 
-    default:
-      op = OP_EXACTMBN;
-      break;
-    }
+  default:
+    op = OP_STR_MBN;
+    break;
   }
+
   return op;
 }
 
@@ -621,31 +689,43 @@ is_strict_real_node(Node* node)
 }
 
 static int
-compile_tree_empty_check(Node* node, regex_t* reg, int emptiness, ScanEnv* env)
+compile_quant_body_with_empty_check(QuantNode* qn, regex_t* reg, ScanEnv* env)
 {
   int r;
-  int saved_num_null_check = reg->num_null_check;
+  int saved_num_empty_check;
+  int emptiness;
+  Node* body;
+
+  body = NODE_BODY((Node* )qn);
+  emptiness = qn->emptiness;
+  saved_num_empty_check = reg->num_empty_check;
 
   if (emptiness != BODY_IS_NOT_EMPTY) {
     r = add_op(reg, OP_EMPTY_CHECK_START);
     if (r != 0) return r;
-    COP(reg)->empty_check_start.mem = reg->num_null_check; /* NULL CHECK ID */
-    reg->num_null_check++;
+    COP(reg)->empty_check_start.mem = reg->num_empty_check; /* NULL CHECK ID */
+    reg->num_empty_check++;
   }
 
-  r = compile_tree(node, reg, env);
+  r = compile_tree(body, reg, env);
   if (r != 0) return r;
 
   if (emptiness != BODY_IS_NOT_EMPTY) {
     if (emptiness == BODY_IS_EMPTY_POSSIBILITY)
       r = add_op(reg, OP_EMPTY_CHECK_END);
-    else if (emptiness == BODY_IS_EMPTY_POSSIBILITY_MEM)
-      r = add_op(reg, OP_EMPTY_CHECK_END_MEMST);
+    else if (emptiness == BODY_IS_EMPTY_POSSIBILITY_MEM) {
+      if (NODE_IS_EMPTY_STATUS_CHECK(qn) != 0)
+        r = add_op(reg, OP_EMPTY_CHECK_END_MEMST);
+      else
+        r = add_op(reg, OP_EMPTY_CHECK_END);
+    }
+#ifdef USE_CALL
     else if (emptiness == BODY_IS_EMPTY_POSSIBILITY_REC)
       r = add_op(reg, OP_EMPTY_CHECK_END_MEMST_PUSH);
+#endif
 
     if (r != 0) return r;
-    COP(reg)->empty_check_end.mem = saved_num_null_check; /* NULL CHECK ID */
+    COP(reg)->empty_check_end.mem = saved_num_empty_check; /* NULL CHECK ID */
   }
   return r;
 }
@@ -682,14 +762,13 @@ compile_tree_n_times(Node* node, int n, regex_t* reg, ScanEnv* env)
 
 static int
 add_compile_string_length(UChar* s ARG_UNUSED, int mb_len, int str_len,
-                          regex_t* reg ARG_UNUSED, int ignore_case)
+                          regex_t* reg ARG_UNUSED)
 {
   return 1;
 }
 
 static int
-add_compile_string(UChar* s, int mb_len, int str_len,
-                   regex_t* reg, int ignore_case)
+add_compile_string(UChar* s, int mb_len, int str_len, regex_t* reg)
 {
   int op;
   int r;
@@ -697,14 +776,14 @@ add_compile_string(UChar* s, int mb_len, int str_len,
   UChar* p;
   UChar* end;
 
-  op = select_str_opcode(mb_len, str_len, ignore_case);
+  op = select_str_opcode(mb_len, str_len);
   r = add_op(reg, op);
   if (r != 0) return r;
 
   byte_len = mb_len * str_len;
   end = s + byte_len;
 
-  if (op == OP_EXACTMBN) {
+  if (op == OP_STR_MBN) {
     p = onigenc_strdup(reg->enc, s, end);
     CHECK_NULL_RETURN_MEMERR(p);
 
@@ -712,11 +791,11 @@ add_compile_string(UChar* s, int mb_len, int str_len,
     COP(reg)->exact_len_n.n   = str_len;
     COP(reg)->exact_len_n.s   = p;
   }
-  else if (IS_NEED_STR_LEN_OP_EXACT(op)) {
+  else if (IS_NEED_STR_LEN_OP(op)) {
     p = onigenc_strdup(reg->enc, s, end);
     CHECK_NULL_RETURN_MEMERR(p);
 
-    if (op == OP_EXACTN_IC)
+    if (op == OP_STR_N_IC)
       COP(reg)->exact_n.n = byte_len;
     else
       COP(reg)->exact_n.n = str_len;
@@ -724,8 +803,8 @@ add_compile_string(UChar* s, int mb_len, int str_len,
     COP(reg)->exact_n.s = p;
   }
   else {
+    xmemset(COP(reg)->exact.s, 0, sizeof(COP(reg)->exact.s));
     xmemcpy(COP(reg)->exact.s, s, (size_t )byte_len);
-    COP(reg)->exact.s[byte_len] = '\0';
   }
 
   return 0;
@@ -734,7 +813,7 @@ add_compile_string(UChar* s, int mb_len, int str_len,
 static int
 compile_length_string_node(Node* node, regex_t* reg)
 {
-  int rlen, r, len, prev_len, slen, ambig;
+  int rlen, r, len, prev_len, slen;
   UChar *p, *prev;
   StrNode* sn;
   OnigEncoding enc = reg->enc;
@@ -743,7 +822,7 @@ compile_length_string_node(Node* node, regex_t* reg)
   if (sn->end <= sn->s)
     return 0;
 
-  ambig = NODE_STRING_IS_AMBIG(node);
+  if (NODE_STRING_IS_CASE_FOLD_MATCH(node) != 0) return 1;
 
   p = prev = sn->s;
   prev_len = enclen(enc, p);
@@ -757,7 +836,7 @@ compile_length_string_node(Node* node, regex_t* reg)
       slen++;
     }
     else {
-      r = add_compile_string_length(prev, prev_len, slen, reg, ambig);
+      r = add_compile_string_length(prev, prev_len, slen, reg);
       rlen += r;
       prev = p;
       slen = 1;
@@ -766,25 +845,59 @@ compile_length_string_node(Node* node, regex_t* reg)
     p += len;
   }
 
-  r = add_compile_string_length(prev, prev_len, slen, reg, ambig);
+  r = add_compile_string_length(prev, prev_len, slen, reg);
   rlen += r;
   return rlen;
 }
 
 static int
-compile_length_string_raw_node(StrNode* sn, regex_t* reg)
+compile_length_string_crude_node(StrNode* sn, regex_t* reg)
 {
   if (sn->end <= sn->s)
     return 0;
 
   return add_compile_string_length(sn->s, 1 /* sb */, (int )(sn->end - sn->s),
-                                   reg, 0);
+                                   reg);
+}
+
+static int
+compile_ambig_string_node(Node* node, regex_t* reg)
+{
+  int r;
+  int len;
+  int byte_len;
+  UChar* p;
+  StrNode* sn;
+  OnigEncoding enc = reg->enc;
+
+  sn = STR_(node);
+  len = enclen(enc, sn->s);
+  byte_len = (int )(sn->end - sn->s);
+  if (len == byte_len) {
+    r = add_op(reg, OP_STR_1_IC);
+    if (r != 0) return r;
+
+    xmemset(COP(reg)->exact.s, 0, sizeof(COP(reg)->exact.s));
+    xmemcpy(COP(reg)->exact.s, sn->s, (size_t )byte_len);
+  }
+  else {
+    r = add_op(reg, OP_STR_N_IC);
+    if (r != 0) return r;
+
+    p = onigenc_strdup(enc, sn->s, sn->end);
+    CHECK_NULL_RETURN_MEMERR(p);
+
+    COP(reg)->exact_n.s = p;
+    COP(reg)->exact_n.n = byte_len;
+  }
+
+  return 0;
 }
 
 static int
 compile_string_node(Node* node, regex_t* reg)
 {
-  int r, len, prev_len, slen, ambig;
+  int r, len, prev_len, slen;
   UChar *p, *prev, *end;
   StrNode* sn;
   OnigEncoding enc = reg->enc;
@@ -794,7 +907,9 @@ compile_string_node(Node* node, regex_t* reg)
     return 0;
 
   end = sn->end;
-  ambig = NODE_STRING_IS_AMBIG(node);
+  if (NODE_STRING_IS_CASE_FOLD_MATCH(node) != 0) {
+    return compile_ambig_string_node(node, reg);
+  }
 
   p = prev = sn->s;
   prev_len = enclen(enc, p);
@@ -807,7 +922,7 @@ compile_string_node(Node* node, regex_t* reg)
       slen++;
     }
     else {
-      r = add_compile_string(prev, prev_len, slen, reg, ambig);
+      r = add_compile_string(prev, prev_len, slen, reg);
       if (r != 0) return r;
 
       prev  = p;
@@ -818,16 +933,16 @@ compile_string_node(Node* node, regex_t* reg)
     p += len;
   }
 
-  return add_compile_string(prev, prev_len, slen, reg, ambig);
+  return add_compile_string(prev, prev_len, slen, reg);
 }
 
 static int
-compile_string_raw_node(StrNode* sn, regex_t* reg)
+compile_string_crude_node(StrNode* sn, regex_t* reg)
 {
   if (sn->end <= sn->s)
     return 0;
 
-  return add_compile_string(sn->s, 1 /* sb */, (int )(sn->end - sn->s), reg, 0);
+  return add_compile_string(sn->s, 1 /* sb */, (int )(sn->end - sn->s), reg);
 }
 
 static void*
@@ -891,15 +1006,27 @@ compile_cclass_node(CClassNode* cc, regex_t* reg)
   return 0;
 }
 
+static void
+set_addr_in_repeat_range(regex_t* reg)
+{
+  int i;
+
+  for (i = 0; i < reg->num_repeat; i++) {
+    RepeatRange* p = reg->repeat_range + i;
+    int offset = p->u.offset;
+    p->u.pcode = reg->ops + offset;
+  }
+}
+
 static int
-entry_repeat_range(regex_t* reg, int id, int lower, int upper)
+entry_repeat_range(regex_t* reg, int id, int lower, int upper, int ops_index)
 {
 #define REPEAT_RANGE_ALLOC  4
 
-  OnigRepeatRange* p;
+  RepeatRange* p;
 
   if (reg->repeat_range_alloc == 0) {
-    p = (OnigRepeatRange* )xmalloc(sizeof(OnigRepeatRange) * REPEAT_RANGE_ALLOC);
+    p = (RepeatRange* )xmalloc(sizeof(RepeatRange) * REPEAT_RANGE_ALLOC);
     CHECK_NULL_RETURN_MEMERR(p);
     reg->repeat_range = p;
     reg->repeat_range_alloc = REPEAT_RANGE_ALLOC;
@@ -907,7 +1034,7 @@ entry_repeat_range(regex_t* reg, int id, int lower, int upper)
   else if (reg->repeat_range_alloc <= id) {
     int n;
     n = reg->repeat_range_alloc + REPEAT_RANGE_ALLOC;
-    p = (OnigRepeatRange* )xrealloc(reg->repeat_range, sizeof(OnigRepeatRange) * n);
+    p = (RepeatRange* )xrealloc(reg->repeat_range, sizeof(RepeatRange) * n);
     CHECK_NULL_RETURN_MEMERR(p);
     reg->repeat_range = p;
     reg->repeat_range_alloc = n;
@@ -916,8 +1043,9 @@ entry_repeat_range(regex_t* reg, int id, int lower, int upper)
     p = reg->repeat_range;
   }
 
-  p[id].lower = lower;
-  p[id].upper = (IS_INFINITE_REPEAT(upper) ? 0x7fffffff : upper);
+  p[id].lower    = lower;
+  p[id].upper    = (IS_INFINITE_REPEAT(upper) ? 0x7fffffff : upper);
+  p[id].u.offset = ops_index;
   return 0;
 }
 
@@ -932,24 +1060,16 @@ compile_range_repeat_node(QuantNode* qn, int target_len, int emptiness,
   if (r != 0) return r;
 
   COP(reg)->repeat.id   = num_repeat;
-  COP(reg)->repeat.addr = SIZE_INC_OP + target_len + SIZE_OP_REPEAT_INC;
+  COP(reg)->repeat.addr = SIZE_INC + target_len + OPSIZE_REPEAT_INC;
 
-  r = entry_repeat_range(reg, num_repeat, qn->lower, qn->upper);
+  r = entry_repeat_range(reg, num_repeat, qn->lower, qn->upper,
+                         COP_CURR_OFFSET(reg) + OPSIZE_REPEAT);
   if (r != 0) return r;
 
-  r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, emptiness, env);
+  r = compile_quant_body_with_empty_check(qn, reg, env);
   if (r != 0) return r;
 
-  if (
-#ifdef USE_CALL
-      NODE_IS_IN_MULTI_ENTRY(qn) ||
-#endif
-      NODE_IS_IN_REAL_REPEAT(qn)) {
-    r = add_op(reg, qn->greedy ? OP_REPEAT_INC_SG : OP_REPEAT_INC_NG_SG);
-  }
-  else {
-    r = add_op(reg, qn->greedy ? OP_REPEAT_INC : OP_REPEAT_INC_NG);
-  }
+  r = add_op(reg, qn->greedy ? OP_REPEAT_INC : OP_REPEAT_INC_NG);
   if (r != 0) return r;
 
   COP(reg)->repeat_inc.id = num_repeat;
@@ -985,21 +1105,21 @@ compile_length_quantifier_node(QuantNode* qn, regex_t* reg)
     if (qn->lower <= 1 ||
         int_multiply_cmp(tlen, qn->lower, QUANTIFIER_EXPAND_LIMIT_SIZE) <= 0) {
       if (IS_NOT_NULL(qn->next_head_exact))
-        return SIZE_OP_ANYCHAR_STAR_PEEK_NEXT + tlen * qn->lower;
+        return OPSIZE_ANYCHAR_STAR_PEEK_NEXT + tlen * qn->lower;
       else
-        return SIZE_OP_ANYCHAR_STAR + tlen * qn->lower;
+        return OPSIZE_ANYCHAR_STAR + tlen * qn->lower;
     }
   }
 
   mod_tlen = tlen;
   if (emptiness != BODY_IS_NOT_EMPTY)
-    mod_tlen += SIZE_OP_EMPTY_CHECK_START + SIZE_OP_EMPTY_CHECK_END;
+    mod_tlen += OPSIZE_EMPTY_CHECK_START + OPSIZE_EMPTY_CHECK_END;
 
   if (infinite &&
       (qn->lower <= 1 ||
        int_multiply_cmp(tlen, qn->lower, QUANTIFIER_EXPAND_LIMIT_SIZE) <= 0)) {
     if (qn->lower == 1 && tlen > QUANTIFIER_EXPAND_LIMIT_SIZE) {
-      len = SIZE_OP_JUMP;
+      len = OPSIZE_JUMP;
     }
     else {
       len = tlen * qn->lower;
@@ -1008,36 +1128,36 @@ compile_length_quantifier_node(QuantNode* qn, regex_t* reg)
     if (qn->greedy) {
 #ifdef USE_OP_PUSH_OR_JUMP_EXACT
       if (IS_NOT_NULL(qn->head_exact))
-        len += SIZE_OP_PUSH_OR_JUMP_EXACT1 + mod_tlen + SIZE_OP_JUMP;
+        len += OPSIZE_PUSH_OR_JUMP_EXACT1 + mod_tlen + OPSIZE_JUMP;
       else
 #endif
       if (IS_NOT_NULL(qn->next_head_exact))
-        len += SIZE_OP_PUSH_IF_PEEK_NEXT + mod_tlen + SIZE_OP_JUMP;
+        len += OPSIZE_PUSH_IF_PEEK_NEXT + mod_tlen + OPSIZE_JUMP;
       else
-        len += SIZE_OP_PUSH + mod_tlen + SIZE_OP_JUMP;
+        len += OPSIZE_PUSH + mod_tlen + OPSIZE_JUMP;
     }
     else
-      len += SIZE_OP_JUMP + mod_tlen + SIZE_OP_PUSH;
+      len += OPSIZE_JUMP + mod_tlen + OPSIZE_PUSH;
   }
   else if (qn->upper == 0) {
-    if (qn->is_refered != 0) { /* /(?<n>..){0}/ */
-      len = SIZE_OP_JUMP + tlen;
+    if (qn->include_referred != 0) { /* /(?<n>..){0}/ */
+      len = OPSIZE_JUMP + tlen;
     }
     else
       len = 0;
   }
   else if (!infinite && qn->greedy &&
            (qn->upper == 1 ||
-            int_multiply_cmp(tlen + SIZE_OP_PUSH, qn->upper,
+            int_multiply_cmp(tlen + OPSIZE_PUSH, qn->upper,
                              QUANTIFIER_EXPAND_LIMIT_SIZE) <= 0)) {
     len = tlen * qn->lower;
-    len += (SIZE_OP_PUSH + tlen) * (qn->upper - qn->lower);
+    len += (OPSIZE_PUSH + tlen) * (qn->upper - qn->lower);
   }
   else if (!qn->greedy && qn->upper == 1 && qn->lower == 0) { /* '??' */
-    len = SIZE_OP_PUSH + SIZE_OP_JUMP + tlen;
+    len = OPSIZE_PUSH + OPSIZE_JUMP + tlen;
   }
   else {
-    len = SIZE_OP_REPEAT_INC + mod_tlen + SIZE_OP_REPEAT;
+    len = OPSIZE_REPEAT_INC + mod_tlen + OPSIZE_REPEAT;
   }
 
   return len;
@@ -1078,7 +1198,7 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
 
   mod_tlen = tlen;
   if (emptiness != BODY_IS_NOT_EMPTY)
-    mod_tlen += SIZE_OP_EMPTY_CHECK_START + SIZE_OP_EMPTY_CHECK_END;
+    mod_tlen += OPSIZE_EMPTY_CHECK_START + OPSIZE_EMPTY_CHECK_END;
 
   if (infinite &&
       (qn->lower <= 1 ||
@@ -1091,16 +1211,16 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
       if (qn->greedy) {
 #ifdef USE_OP_PUSH_OR_JUMP_EXACT
         if (IS_NOT_NULL(qn->head_exact))
-          COP(reg)->jump.addr = SIZE_OP_PUSH_OR_JUMP_EXACT1 + SIZE_INC_OP;
+          COP(reg)->jump.addr = OPSIZE_PUSH_OR_JUMP_EXACT1 + SIZE_INC;
         else
 #endif
         if (IS_NOT_NULL(qn->next_head_exact))
-          COP(reg)->jump.addr = SIZE_OP_PUSH_IF_PEEK_NEXT + SIZE_INC_OP;
+          COP(reg)->jump.addr = OPSIZE_PUSH_IF_PEEK_NEXT + SIZE_INC;
         else
-          COP(reg)->jump.addr = SIZE_OP_PUSH + SIZE_INC_OP;
+          COP(reg)->jump.addr = OPSIZE_PUSH + SIZE_INC;
       }
       else {
-        COP(reg)->jump.addr = SIZE_OP_JUMP + SIZE_INC_OP;
+        COP(reg)->jump.addr = OPSIZE_JUMP + SIZE_INC;
       }
     }
     else {
@@ -1113,36 +1233,36 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
       if (IS_NOT_NULL(qn->head_exact)) {
         r = add_op(reg, OP_PUSH_OR_JUMP_EXACT1);
         if (r != 0) return r;
-        COP(reg)->push_or_jump_exact1.addr = SIZE_INC_OP + mod_tlen + SIZE_OP_JUMP;
+        COP(reg)->push_or_jump_exact1.addr = SIZE_INC + mod_tlen + OPSIZE_JUMP;
         COP(reg)->push_or_jump_exact1.c    = STR_(qn->head_exact)->s[0];
 
-        r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, emptiness, env);
+        r = compile_quant_body_with_empty_check(qn, reg, env);
         if (r != 0) return r;
 
-        addr = -(mod_tlen + (int )SIZE_OP_PUSH_OR_JUMP_EXACT1);
+        addr = -(mod_tlen + (int )OPSIZE_PUSH_OR_JUMP_EXACT1);
       }
       else
 #endif
       if (IS_NOT_NULL(qn->next_head_exact)) {
         r = add_op(reg, OP_PUSH_IF_PEEK_NEXT);
         if (r != 0) return r;
-        COP(reg)->push_if_peek_next.addr = SIZE_INC_OP + mod_tlen + SIZE_OP_JUMP;
+        COP(reg)->push_if_peek_next.addr = SIZE_INC + mod_tlen + OPSIZE_JUMP;
         COP(reg)->push_if_peek_next.c    = STR_(qn->next_head_exact)->s[0];
 
-        r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, emptiness, env);
+        r = compile_quant_body_with_empty_check(qn, reg, env);
         if (r != 0) return r;
 
-        addr = -(mod_tlen + (int )SIZE_OP_PUSH_IF_PEEK_NEXT);
+        addr = -(mod_tlen + (int )OPSIZE_PUSH_IF_PEEK_NEXT);
       }
       else {
         r = add_op(reg, OP_PUSH);
         if (r != 0) return r;
-        COP(reg)->push.addr = SIZE_INC_OP + mod_tlen + SIZE_OP_JUMP;
+        COP(reg)->push.addr = SIZE_INC + mod_tlen + OPSIZE_JUMP;
 
-        r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, emptiness, env);
+        r = compile_quant_body_with_empty_check(qn, reg, env);
         if (r != 0) return r;
 
-        addr = -(mod_tlen + (int )SIZE_OP_PUSH);
+        addr = -(mod_tlen + (int )OPSIZE_PUSH);
       }
 
       r = add_op(reg, OP_JUMP);
@@ -1152,9 +1272,9 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
     else {
       r = add_op(reg, OP_JUMP);
       if (r != 0) return r;
-      COP(reg)->jump.addr = mod_tlen + SIZE_INC_OP;
+      COP(reg)->jump.addr = mod_tlen + SIZE_INC;
 
-      r = compile_tree_empty_check(NODE_QUANT_BODY(qn), reg, emptiness, env);
+      r = compile_quant_body_with_empty_check(qn, reg, env);
       if (r != 0) return r;
 
       r = add_op(reg, OP_PUSH);
@@ -1163,10 +1283,10 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
     }
   }
   else if (qn->upper == 0) {
-    if (qn->is_refered != 0) { /* /(?<n>..){0}/ */
+    if (qn->include_referred != 0) { /* /(?<n>..){0}/ */
       r = add_op(reg, OP_JUMP);
       if (r != 0) return r;
-      COP(reg)->jump.addr = tlen + SIZE_INC_OP;
+      COP(reg)->jump.addr = tlen + SIZE_INC;
 
       r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
     }
@@ -1177,7 +1297,7 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
   }
   else if (! infinite && qn->greedy &&
            (qn->upper == 1 ||
-            int_multiply_cmp(tlen + SIZE_OP_PUSH, qn->upper,
+            int_multiply_cmp(tlen + OPSIZE_PUSH, qn->upper,
                              QUANTIFIER_EXPAND_LIMIT_SIZE) <= 0)) {
     int n = qn->upper - qn->lower;
 
@@ -1185,7 +1305,7 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
     if (r != 0) return r;
 
     for (i = 0; i < n; i++) {
-      int v = onig_positive_int_multiply(n - i, tlen + SIZE_OP_PUSH);
+      int v = onig_positive_int_multiply(n - i, tlen + OPSIZE_PUSH);
       if (v < 0) return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
 
       r = add_op(reg, OP_PUSH);
@@ -1199,11 +1319,11 @@ compile_quantifier_node(QuantNode* qn, regex_t* reg, ScanEnv* env)
   else if (! qn->greedy && qn->upper == 1 && qn->lower == 0) { /* '??' */
     r = add_op(reg, OP_PUSH);
     if (r != 0) return r;
-    COP(reg)->push.addr = SIZE_INC_OP + SIZE_OP_JUMP;
+    COP(reg)->push.addr = SIZE_INC + OPSIZE_JUMP;
 
     r = add_op(reg, OP_JUMP);
     if (r != 0) return r;
-    COP(reg)->jump.addr = tlen + SIZE_INC_OP;
+    COP(reg)->jump.addr = tlen + SIZE_INC;
 
     r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
   }
@@ -1260,35 +1380,35 @@ compile_length_bag_node(BagNode* node, regex_t* reg)
 #ifdef USE_CALL
 
     if (node->m.regnum == 0 && NODE_IS_CALLED(node)) {
-      len = tlen + SIZE_OP_CALL + SIZE_OP_JUMP + SIZE_OP_RETURN;
+      len = tlen + OPSIZE_CALL + OPSIZE_JUMP + OPSIZE_RETURN;
       return len;
     }
 
     if (NODE_IS_CALLED(node)) {
-      len = SIZE_OP_MEMORY_START_PUSH + tlen
-        + SIZE_OP_CALL + SIZE_OP_JUMP + SIZE_OP_RETURN;
-      if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+      len = OPSIZE_MEM_START_PUSH + tlen
+        + OPSIZE_CALL + OPSIZE_JUMP + OPSIZE_RETURN;
+      if (MEM_STATUS_AT0(reg->push_mem_end, node->m.regnum))
         len += (NODE_IS_RECURSION(node)
-                ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_PUSH);
+                ? OPSIZE_MEM_END_PUSH_REC : OPSIZE_MEM_END_PUSH);
       else
         len += (NODE_IS_RECURSION(node)
-                ? SIZE_OP_MEMORY_END_REC : SIZE_OP_MEMORY_END);
+                ? OPSIZE_MEM_END_REC : OPSIZE_MEM_END);
     }
     else if (NODE_IS_RECURSION(node)) {
-      len = SIZE_OP_MEMORY_START_PUSH;
-      len += tlen + (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum)
-                     ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_REC);
+      len = OPSIZE_MEM_START_PUSH;
+      len += tlen + (MEM_STATUS_AT0(reg->push_mem_end, node->m.regnum)
+                     ? OPSIZE_MEM_END_PUSH_REC : OPSIZE_MEM_END_REC);
     }
     else
 #endif
     {
-      if (MEM_STATUS_AT0(reg->bt_mem_start, node->m.regnum))
-        len = SIZE_OP_MEMORY_START_PUSH;
+      if (MEM_STATUS_AT0(reg->push_mem_start, node->m.regnum))
+        len = OPSIZE_MEM_START_PUSH;
       else
-        len = SIZE_OP_MEMORY_START;
+        len = OPSIZE_MEM_START;
 
-      len += tlen + (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum)
-                     ? SIZE_OP_MEMORY_END_PUSH : SIZE_OP_MEMORY_END);
+      len += tlen + (MEM_STATUS_AT0(reg->push_mem_end, node->m.regnum)
+                     ? OPSIZE_MEM_END_PUSH : OPSIZE_MEM_END);
     }
     break;
 
@@ -1303,10 +1423,10 @@ compile_length_bag_node(BagNode* node, regex_t* reg)
 
       v = onig_positive_int_multiply(qn->lower, tlen);
       if (v < 0) return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
-      len = v + SIZE_OP_PUSH + tlen + SIZE_OP_POP_OUT + SIZE_OP_JUMP;
+      len = v + OPSIZE_PUSH + tlen + OPSIZE_POP_OUT + OPSIZE_JUMP;
     }
     else {
-      len = SIZE_OP_ATOMIC_START + tlen + SIZE_OP_ATOMIC_END;
+      len = OPSIZE_ATOMIC_START + tlen + OPSIZE_ATOMIC_END;
     }
     break;
 
@@ -1318,8 +1438,8 @@ compile_length_bag_node(BagNode* node, regex_t* reg)
 
       len = compile_length_tree(cond, reg);
       if (len < 0) return len;
-      len += SIZE_OP_PUSH;
-      len += SIZE_OP_ATOMIC_START + SIZE_OP_ATOMIC_END;
+      len += OPSIZE_PUSH;
+      len += OPSIZE_ATOMIC_START + OPSIZE_ATOMIC_END;
 
       if (IS_NOT_NULL(Then)) {
         tlen = compile_length_tree(Then, reg);
@@ -1327,7 +1447,7 @@ compile_length_bag_node(BagNode* node, regex_t* reg)
         len += tlen;
       }
 
-      len += SIZE_OP_JUMP + SIZE_OP_ATOMIC_END;
+      len += OPSIZE_JUMP + OPSIZE_ATOMIC_END;
 
       if (IS_NOT_NULL(Else)) {
         tlen = compile_length_tree(Else, reg);
@@ -1352,24 +1472,25 @@ static int
 compile_bag_memory_node(BagNode* node, regex_t* reg, ScanEnv* env)
 {
   int r;
-  int len;
 
 #ifdef USE_CALL
   if (NODE_IS_CALLED(node)) {
+    int len;
+
     r = add_op(reg, OP_CALL);
     if (r != 0) return r;
 
-    node->m.called_addr = COP_CURR_OFFSET(reg) + 1 + SIZE_OP_JUMP;
+    node->m.called_addr = COP_CURR_OFFSET(reg) + 1 + OPSIZE_JUMP;
     NODE_STATUS_ADD(node, ADDR_FIXED);
     COP(reg)->call.addr = (int )node->m.called_addr;
 
     if (node->m.regnum == 0) {
       len = compile_length_tree(NODE_BAG_BODY(node), reg);
-      len += SIZE_OP_RETURN;
+      len += OPSIZE_RETURN;
 
       r = add_op(reg, OP_JUMP);
       if (r != 0) return r;
-      COP(reg)->jump.addr = len + SIZE_INC_OP;
+      COP(reg)->jump.addr = len + SIZE_INC;
 
       r = compile_tree(NODE_BAG_BODY(node), reg, env);
       if (r != 0) return r;
@@ -1379,25 +1500,24 @@ compile_bag_memory_node(BagNode* node, regex_t* reg, ScanEnv* env)
     }
     else {
       len = compile_length_tree(NODE_BAG_BODY(node), reg);
-      len += (SIZE_OP_MEMORY_START_PUSH + SIZE_OP_RETURN);
-      if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+      len += (OPSIZE_MEM_START_PUSH + OPSIZE_RETURN);
+      if (MEM_STATUS_AT0(reg->push_mem_end, node->m.regnum))
         len += (NODE_IS_RECURSION(node)
-                ? SIZE_OP_MEMORY_END_PUSH_REC : SIZE_OP_MEMORY_END_PUSH);
+                ? OPSIZE_MEM_END_PUSH_REC : OPSIZE_MEM_END_PUSH);
       else
-        len += (NODE_IS_RECURSION(node)
-                ? SIZE_OP_MEMORY_END_REC : SIZE_OP_MEMORY_END);
+        len += (NODE_IS_RECURSION(node) ? OPSIZE_MEM_END_REC : OPSIZE_MEM_END);
 
       r = add_op(reg, OP_JUMP);
       if (r != 0) return r;
-      COP(reg)->jump.addr = len + SIZE_INC_OP;
+      COP(reg)->jump.addr = len + SIZE_INC;
     }
   }
 #endif
 
-  if (MEM_STATUS_AT0(reg->bt_mem_start, node->m.regnum))
-    r = add_op(reg, OP_MEMORY_START_PUSH);
+  if (MEM_STATUS_AT0(reg->push_mem_start, node->m.regnum))
+    r = add_op(reg, OP_MEM_START_PUSH);
   else
-    r = add_op(reg, OP_MEMORY_START);
+    r = add_op(reg, OP_MEM_START);
   if (r != 0) return r;
   COP(reg)->memory_start.num = node->m.regnum;
 
@@ -1405,11 +1525,11 @@ compile_bag_memory_node(BagNode* node, regex_t* reg, ScanEnv* env)
   if (r != 0) return r;
 
 #ifdef USE_CALL
-  if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
+  if (MEM_STATUS_AT0(reg->push_mem_end, node->m.regnum))
     r = add_op(reg, (NODE_IS_RECURSION(node)
-                     ? OP_MEMORY_END_PUSH_REC : OP_MEMORY_END_PUSH));
+                     ? OP_MEM_END_PUSH_REC : OP_MEM_END_PUSH));
   else
-    r = add_op(reg, (NODE_IS_RECURSION(node) ? OP_MEMORY_END_REC : OP_MEMORY_END));
+    r = add_op(reg, (NODE_IS_RECURSION(node) ? OP_MEM_END_REC : OP_MEM_END));
   if (r != 0) return r;
   COP(reg)->memory_end.num = node->m.regnum;
 
@@ -1418,10 +1538,10 @@ compile_bag_memory_node(BagNode* node, regex_t* reg, ScanEnv* env)
     r = add_op(reg, OP_RETURN);
   }
 #else
-  if (MEM_STATUS_AT0(reg->bt_mem_end, node->m.regnum))
-    r = add_op(reg, OP_MEMORY_END_PUSH);
+  if (MEM_STATUS_AT0(reg->push_mem_end, node->m.regnum))
+    r = add_op(reg, OP_MEM_END_PUSH);
   else
-    r = add_op(reg, OP_MEMORY_END);
+    r = add_op(reg, OP_MEM_END);
   if (r != 0) return r;
   COP(reg)->memory_end.num = node->m.regnum;
 #endif
@@ -1454,7 +1574,7 @@ compile_bag_node(BagNode* node, regex_t* reg, ScanEnv* env)
 
       r = add_op(reg, OP_PUSH);
       if (r != 0) return r;
-      COP(reg)->push.addr = SIZE_INC_OP + len + SIZE_OP_POP_OUT + SIZE_OP_JUMP;
+      COP(reg)->push.addr = SIZE_INC + len + OPSIZE_POP_OUT + OPSIZE_JUMP;
 
       r = compile_tree(NODE_QUANT_BODY(qn), reg, env);
       if (r != 0) return r;
@@ -1463,7 +1583,7 @@ compile_bag_node(BagNode* node, regex_t* reg, ScanEnv* env)
 
       r = add_op(reg, OP_JUMP);
       if (r != 0) return r;
-      COP(reg)->jump.addr = -((int )SIZE_OP_PUSH + len + (int )SIZE_OP_POP_OUT);
+      COP(reg)->jump.addr = -((int )OPSIZE_PUSH + len + (int )OPSIZE_POP_OUT);
     }
     else {
       r = add_op(reg, OP_ATOMIC_START);
@@ -1493,11 +1613,11 @@ compile_bag_node(BagNode* node, regex_t* reg, ScanEnv* env)
       else
         then_len = 0;
 
-      jump_len = cond_len + then_len + SIZE_OP_ATOMIC_END + SIZE_OP_JUMP;
+      jump_len = cond_len + then_len + OPSIZE_ATOMIC_END + OPSIZE_JUMP;
 
       r = add_op(reg, OP_PUSH);
       if (r != 0) return r;
-      COP(reg)->push.addr = SIZE_INC_OP + jump_len;
+      COP(reg)->push.addr = SIZE_INC + jump_len;
 
       r = compile_tree(cond, reg, env);
       if (r != 0) return r;
@@ -1518,7 +1638,7 @@ compile_bag_node(BagNode* node, regex_t* reg, ScanEnv* env)
 
       r = add_op(reg, OP_JUMP);
       if (r != 0) return r;
-      COP(reg)->jump.addr = SIZE_OP_ATOMIC_END + else_len + SIZE_INC_OP;
+      COP(reg)->jump.addr = OPSIZE_ATOMIC_END + else_len + SIZE_INC;
 
       r = add_op(reg, OP_ATOMIC_END);
       if (r != 0) return r;
@@ -1546,16 +1666,16 @@ compile_length_anchor_node(AnchorNode* node, regex_t* reg)
 
   switch (node->type) {
   case ANCR_PREC_READ:
-    len = SIZE_OP_PREC_READ_START + tlen + SIZE_OP_PREC_READ_END;
+    len = OPSIZE_PREC_READ_START + tlen + OPSIZE_PREC_READ_END;
     break;
   case ANCR_PREC_READ_NOT:
-    len = SIZE_OP_PREC_READ_NOT_START + tlen + SIZE_OP_PREC_READ_NOT_END;
+    len = OPSIZE_PREC_READ_NOT_START + tlen + OPSIZE_PREC_READ_NOT_END;
     break;
   case ANCR_LOOK_BEHIND:
-    len = SIZE_OP_LOOK_BEHIND + tlen;
+    len = OPSIZE_LOOK_BEHIND + tlen;
     break;
   case ANCR_LOOK_BEHIND_NOT:
-    len = SIZE_OP_LOOK_BEHIND_NOT_START + tlen + SIZE_OP_LOOK_BEHIND_NOT_END;
+    len = OPSIZE_LOOK_BEHIND_NOT_START + tlen + OPSIZE_LOOK_BEHIND_NOT_END;
     break;
 
   case ANCR_WORD_BOUNDARY:
@@ -1564,7 +1684,7 @@ compile_length_anchor_node(AnchorNode* node, regex_t* reg)
   case ANCR_WORD_BEGIN:
   case ANCR_WORD_END:
 #endif
-    len = SIZE_OP_WORD_BOUNDARY;
+    len = OPSIZE_WORD_BOUNDARY;
     break;
 
   case ANCR_TEXT_SEGMENT_BOUNDARY:
@@ -1648,7 +1768,7 @@ compile_anchor_node(AnchorNode* node, regex_t* reg, ScanEnv* env)
 
     r = add_op(reg, OP_PREC_READ_NOT_START);
     if (r != 0) return r;
-    COP(reg)->prec_read_not_start.addr = SIZE_INC_OP + len + SIZE_OP_PREC_READ_NOT_END;
+    COP(reg)->prec_read_not_start.addr = SIZE_INC + len + OPSIZE_PREC_READ_NOT_END;
     r = compile_tree(NODE_ANCHOR_BODY(node), reg, env);
     if (r != 0) return r;
     r = add_op(reg, OP_PREC_READ_NOT_END);
@@ -1678,7 +1798,7 @@ compile_anchor_node(AnchorNode* node, regex_t* reg, ScanEnv* env)
       len = compile_length_tree(NODE_ANCHOR_BODY(node), reg);
       r = add_op(reg, OP_LOOK_BEHIND_NOT_START);
       if (r != 0) return r;
-      COP(reg)->look_behind_not_start.addr = SIZE_INC_OP + len + SIZE_OP_LOOK_BEHIND_NOT_END;
+      COP(reg)->look_behind_not_start.addr = SIZE_INC + len + OPSIZE_LOOK_BEHIND_NOT_END;
 
       if (node->char_len < 0) {
         r = get_char_len_node(NODE_ANCHOR_BODY(node), reg, &n);
@@ -1764,25 +1884,25 @@ compile_length_gimmick_node(GimmickNode* node, regex_t* reg)
 
   switch (node->type) {
   case GIMMICK_FAIL:
-    len = SIZE_OP_FAIL;
+    len = OPSIZE_FAIL;
     break;
 
   case GIMMICK_SAVE:
-    len = SIZE_OP_PUSH_SAVE_VAL;
+    len = OPSIZE_PUSH_SAVE_VAL;
     break;
 
   case GIMMICK_UPDATE_VAR:
-    len = SIZE_OP_UPDATE_VAR;
+    len = OPSIZE_UPDATE_VAR;
     break;
 
 #ifdef USE_CALLOUT
   case GIMMICK_CALLOUT:
     switch (node->detail_type) {
     case ONIG_CALLOUT_OF_CONTENTS:
-      len = SIZE_OP_CALLOUT_CONTENTS;
+      len = OPSIZE_CALLOUT_CONTENTS;
       break;
     case ONIG_CALLOUT_OF_NAME:
-      len = SIZE_OP_CALLOUT_NAME;
+      len = OPSIZE_CALLOUT_NAME;
       break;
 
     default:
@@ -1821,13 +1941,13 @@ compile_length_tree(Node* node, regex_t* reg)
         r += compile_length_tree(NODE_CAR(node), reg);
         n++;
       } while (IS_NOT_NULL(node = NODE_CDR(node)));
-      r += (SIZE_OP_PUSH + SIZE_OP_JUMP) * (n - 1);
+      r += (OPSIZE_PUSH + OPSIZE_JUMP) * (n - 1);
     }
     break;
 
   case NODE_STRING:
-    if (NODE_STRING_IS_RAW(node))
-      r = compile_length_string_raw_node(STR_(node), reg);
+    if (NODE_STRING_IS_CRUDE(node))
+      r = compile_length_string_crude_node(STR_(node), reg);
     else
       r = compile_length_string_node(node, reg);
     break;
@@ -1841,12 +1961,12 @@ compile_length_tree(Node* node, regex_t* reg)
     break;
 
   case NODE_BACKREF:
-    r = SIZE_OP_BACKREF;
+    r = OPSIZE_BACKREF;
     break;
 
 #ifdef USE_CALL
   case NODE_CALL:
-    r = SIZE_OP_CALL;
+    r = OPSIZE_CALL;
     break;
 #endif
 
@@ -1893,7 +2013,7 @@ compile_tree(Node* node, regex_t* reg, ScanEnv* env)
       do {
         len += compile_length_tree(NODE_CAR(x), reg);
         if (IS_NOT_NULL(NODE_CDR(x))) {
-          len += SIZE_OP_PUSH + SIZE_OP_JUMP;
+          len += OPSIZE_PUSH + OPSIZE_JUMP;
         }
       } while (IS_NOT_NULL(x = NODE_CDR(x)));
       pos = COP_CURR_OFFSET(reg) + 1 + len;  /* goal position */
@@ -1904,7 +2024,7 @@ compile_tree(Node* node, regex_t* reg, ScanEnv* env)
           enum OpCode push = NODE_IS_SUPER(node) ? OP_PUSH_SUPER : OP_PUSH;
           r = add_op(reg, push);
           if (r != 0) break;
-          COP(reg)->push.addr = SIZE_INC_OP + len + SIZE_OP_JUMP;
+          COP(reg)->push.addr = SIZE_INC + len + OPSIZE_JUMP;
         }
         r = compile_tree(NODE_CAR(node), reg, env);
         if (r != 0) break;
@@ -1919,8 +2039,8 @@ compile_tree(Node* node, regex_t* reg, ScanEnv* env)
     break;
 
   case NODE_STRING:
-    if (NODE_STRING_IS_RAW(node))
-      r = compile_string_raw_node(STR_(node), reg);
+    if (NODE_STRING_IS_CRUDE(node))
+      r = compile_string_crude_node(STR_(node), reg);
     else
       r = compile_string_node(node, reg);
     break;
@@ -2090,8 +2210,9 @@ noname_disable_map(Node** plink, GroupNumRemap* map, int* counter)
       Node** ptarget = &(NODE_BODY(node));
       Node*  old = *ptarget;
       r = noname_disable_map(ptarget, map, counter);
+      if (r != 0) return r;
       if (*ptarget != old && NODE_TYPE(*ptarget) == NODE_QUANT) {
-        onig_reduce_nested_quantifier(node, *ptarget);
+        r = onig_reduce_nested_quantifier(node);
       }
     }
     break;
@@ -2303,11 +2424,11 @@ disable_noname_group_capture(Node** root, regex_t* reg, ScanEnv* env)
     }
   }
 
-  loc = env->capture_history;
-  MEM_STATUS_CLEAR(env->capture_history);
+  loc = env->cap_history;
+  MEM_STATUS_CLEAR(env->cap_history);
   for (i = 1; i <= ONIG_MAX_CAPTURE_HISTORY_GROUP; i++) {
     if (MEM_STATUS_AT(loc, i)) {
-      MEM_STATUS_ON_SIMPLE(env->capture_history, map[i].new_val);
+      MEM_STATUS_ON_SIMPLE(env->cap_history, map[i].new_val);
     }
   }
 
@@ -2683,7 +2804,7 @@ is_exclusive(Node* x, Node* y, regex_t* reg)
 
           len = NODE_STRING_LEN(x);
           if (len > NODE_STRING_LEN(y)) len = NODE_STRING_LEN(y);
-          if (NODE_STRING_IS_AMBIG(x) || NODE_STRING_IS_AMBIG(y)) {
+          if (NODE_STRING_IS_CASE_FOLD_MATCH(x) || NODE_STRING_IS_CASE_FOLD_MATCH(y)) {
             /* tiny version */
             return 0;
           }
@@ -2743,7 +2864,7 @@ get_head_value_node(Node* node, int exact, regex_t* reg)
         break;
 
       if (exact == 0 ||
-          ! IS_IGNORECASE(reg->options) || NODE_STRING_IS_RAW(node)) {
+          ! IS_IGNORECASE(reg->options) || NODE_STRING_IS_CRUDE(node)) {
         n = node;
       }
     }
@@ -2871,9 +2992,9 @@ tree_min_len(Node* node, ScanEnv* env)
       if (NODE_IS_RECURSION(node)) break;
 
       backs = BACKREFS_P(br);
-      len = tree_min_len(mem_env[backs[0]].node, env);
+      len = tree_min_len(mem_env[backs[0]].mem_node, env);
       for (i = 1; i < br->back_num; i++) {
-        tmin = tree_min_len(mem_env[backs[i]].node, env);
+        tmin = tree_min_len(mem_env[backs[i]].mem_node, env);
         if (len > tmin) len = tmin;
       }
     }
@@ -3042,7 +3163,7 @@ tree_max_len(Node* node, ScanEnv* env)
       }
       backs = BACKREFS_P(br);
       for (i = 0; i < br->back_num; i++) {
-        tmax = tree_max_len(mem_env[backs[i]].node, env);
+        tmax = tree_max_len(mem_env[backs[i]].mem_node, env);
         if (len < tmax) len = tmax;
       }
     }
@@ -3179,7 +3300,7 @@ check_backrefs(Node* node, ScanEnv* env)
         if (backs[i] > env->num_mem)
           return ONIGERR_INVALID_BACKREF;
 
-        NODE_STATUS_ADD(mem_env[backs[i]].node, BACKREF);
+        NODE_STATUS_ADD(mem_env[backs[i]].mem_node, BACKREF);
       }
       r = 0;
     }
@@ -3193,6 +3314,204 @@ check_backrefs(Node* node, ScanEnv* env)
   return r;
 }
 
+static int
+set_empty_repeat_node_trav(Node* node, Node* empty, ScanEnv* env)
+{
+  int r;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      r = set_empty_repeat_node_trav(NODE_CAR(node), empty, env);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_ANCHOR:
+    {
+      AnchorNode* an = ANCHOR_(node);
+
+      if (! ANCHOR_HAS_BODY(an)) {
+        r = 0;
+        break;
+      }
+
+      switch (an->type) {
+      case ANCR_PREC_READ:
+      case ANCR_LOOK_BEHIND:
+        empty = NULL_NODE;
+        break;
+      default:
+        break;
+      }
+      r = set_empty_repeat_node_trav(NODE_BODY(node), empty, env);
+    }
+    break;
+
+  case NODE_QUANT:
+    {
+      QuantNode* qn = QUANT_(node);
+
+      if (qn->emptiness != BODY_IS_NOT_EMPTY) empty = node;
+      r = set_empty_repeat_node_trav(NODE_BODY(node), empty, env);
+    }
+    break;
+
+  case NODE_BAG:
+    if (IS_NOT_NULL(NODE_BODY(node))) {
+      r = set_empty_repeat_node_trav(NODE_BODY(node), empty, env);
+      if (r != 0) return r;
+    }
+    {
+      BagNode* en = BAG_(node);
+
+      if (en->type == BAG_MEMORY) {
+        if (NODE_IS_BACKREF(node)) {
+          if (IS_NOT_NULL(empty))
+            SCANENV_MEMENV(env)[en->m.regnum].empty_repeat_node = empty;
+        }
+      }
+      else if (en->type == BAG_IF_ELSE) {
+        if (IS_NOT_NULL(en->te.Then)) {
+          r = set_empty_repeat_node_trav(en->te.Then, empty, env);
+          if (r != 0) return r;
+        }
+        if (IS_NOT_NULL(en->te.Else)) {
+          r = set_empty_repeat_node_trav(en->te.Else, empty, env);
+        }
+      }
+    }
+    break;
+
+  default:
+    r = 0;
+    break;
+  }
+
+  return r;
+}
+
+static int
+is_ancestor_node(Node* node, Node* me)
+{
+  Node* parent;
+
+  while ((parent = NODE_PARENT(me)) != NULL_NODE) {
+    if (parent == node) return 1;
+    me = parent;
+  }
+  return 0;
+}
+
+static void
+set_empty_status_check_trav(Node* node, ScanEnv* env)
+{
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      set_empty_status_check_trav(NODE_CAR(node), env);
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_ANCHOR:
+    {
+      AnchorNode* an = ANCHOR_(node);
+
+      if (! ANCHOR_HAS_BODY(an)) break;
+      set_empty_status_check_trav(NODE_BODY(node), env);
+    }
+    break;
+
+  case NODE_QUANT:
+    set_empty_status_check_trav(NODE_BODY(node), env);
+    break;
+
+  case NODE_BAG:
+    if (IS_NOT_NULL(NODE_BODY(node)))
+      set_empty_status_check_trav(NODE_BODY(node), env);
+    {
+      BagNode* en = BAG_(node);
+
+      if (en->type == BAG_IF_ELSE) {
+        if (IS_NOT_NULL(en->te.Then)) {
+          set_empty_status_check_trav(en->te.Then, env);
+        }
+        if (IS_NOT_NULL(en->te.Else)) {
+          set_empty_status_check_trav(en->te.Else, env);
+        }
+      }
+    }
+    break;
+
+  case NODE_BACKREF:
+    {
+      int i;
+      int* backs;
+      MemEnv* mem_env = SCANENV_MEMENV(env);
+      BackRefNode* br = BACKREF_(node);
+      backs = BACKREFS_P(br);
+      for (i = 0; i < br->back_num; i++) {
+        Node* ernode = mem_env[backs[i]].empty_repeat_node;
+        if (IS_NOT_NULL(ernode)) {
+          if (! is_ancestor_node(ernode, node)) {
+            MEM_STATUS_LIMIT_ON(env->reg->empty_status_mem, backs[i]);
+            NODE_STATUS_ADD(ernode, EMPTY_STATUS_CHECK);
+            NODE_STATUS_ADD(mem_env[backs[i]].mem_node, EMPTY_STATUS_CHECK);
+          }
+        }
+      }
+    }
+    break;
+
+  default:
+    break;
+  }
+}
+
+static void
+set_parent_node_trav(Node* node, Node* parent)
+{
+  NODE_PARENT(node) = parent;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      set_parent_node_trav(NODE_CAR(node), node);
+    } while (IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_ANCHOR:
+    if (! ANCHOR_HAS_BODY(ANCHOR_(node))) break;
+    set_parent_node_trav(NODE_BODY(node), node);
+    break;
+
+  case NODE_QUANT:
+    set_parent_node_trav(NODE_BODY(node), node);
+    break;
+
+  case NODE_BAG:
+    if (IS_NOT_NULL(NODE_BODY(node)))
+      set_parent_node_trav(NODE_BODY(node), node);
+    {
+      BagNode* en = BAG_(node);
+
+      if (en->type == BAG_IF_ELSE) {
+        if (IS_NOT_NULL(en->te.Then))
+          set_parent_node_trav(en->te.Then, node);
+        if (IS_NOT_NULL(en->te.Else)) {
+          set_parent_node_trav(en->te.Else, node);
+        }
+      }
+    }
+    break;
+
+  default:
+    break;
+  }
+}
+
 
 #ifdef USE_CALL
 
@@ -3298,6 +3617,9 @@ infinite_recursive_call_check(Node* node, ScanEnv* env, int head)
           if ((eret & RECURSION_MUST) == 0)
             r &= ~RECURSION_MUST;
         }
+        else {
+          r &= ~RECURSION_MUST;
+        }
       }
       else {
         r = infinite_recursive_call_check(NODE_BODY(node), env, head);
@@ -3472,7 +3794,7 @@ recursive_call_check_trav(Node* node, ScanEnv* env, int state)
     r = recursive_call_check_trav(NODE_BODY(node), env, state);
     if (QUANT_(node)->upper == 0) {
       if (r == FOUND_CALLED_NODE)
-        QUANT_(node)->is_refered = 1;
+        QUANT_(node)->include_referred = 1;
     }
     break;
 
@@ -3495,8 +3817,10 @@ recursive_call_check_trav(Node* node, ScanEnv* env, int state)
           if (! NODE_IS_RECURSION(node)) {
             NODE_STATUS_ADD(node, MARK1);
             r = recursive_call_check(NODE_BODY(node));
-            if (r != 0)
+            if (r != 0) {
               NODE_STATUS_ADD(node, RECURSION);
+              MEM_STATUS_ON(env->backtrack_mem, en->m.regnum);
+            }
             NODE_STATUS_REMOVE(node, MARK1);
           }
 
@@ -3537,6 +3861,96 @@ recursive_call_check_trav(Node* node, ScanEnv* env, int state)
 
 #endif
 
+static void
+remove_from_list(Node* prev, Node* a)
+{
+  if (NODE_CDR(prev) != a) return ;
+
+  NODE_CDR(prev) = NODE_CDR(a);
+  NODE_CDR(a) = NULL_NODE;
+}
+
+static int
+reduce_string_list(Node* node)
+{
+  int r = 0;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+    {
+      Node* prev;
+      Node* curr;
+      Node* prev_node;
+      Node* next_node;
+
+      prev = NULL_NODE;
+      do {
+        next_node = NODE_CDR(node);
+        curr = NODE_CAR(node);
+        if (NODE_TYPE(curr) == NODE_STRING) {
+          if (IS_NULL(prev) || STR_(curr)->flag != STR_(prev)->flag) {
+            prev = curr;
+            prev_node = node;
+          }
+          else {
+            r = node_str_node_cat(prev, curr);
+            if (r != 0) return r;
+            remove_from_list(prev_node, node);
+            onig_node_free(node);
+          }
+        }
+        else {
+          prev = NULL_NODE;
+          prev_node = node;
+        }
+
+        node = next_node;
+      } while (r == 0 && IS_NOT_NULL(node));
+    }
+    break;
+
+  case NODE_ALT:
+    do {
+      r = reduce_string_list(NODE_CAR(node));
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_ANCHOR:
+    if (IS_NULL(NODE_BODY(node)))
+      break;
+    /* fall */
+  case NODE_QUANT:
+    r = reduce_string_list(NODE_BODY(node));
+    break;
+
+  case NODE_BAG:
+    {
+      BagNode* en = BAG_(node);
+
+      r = reduce_string_list(NODE_BODY(node));
+      if (r != 0) return r;
+
+      if (en->type == BAG_IF_ELSE) {
+        if (IS_NOT_NULL(en->te.Then)) {
+          r = reduce_string_list(en->te.Then);
+          if (r != 0) return r;
+        }
+        if (IS_NOT_NULL(en->te.Else)) {
+          r = reduce_string_list(en->te.Else);
+          if (r != 0) return r;
+        }
+      }
+    }
+    break;
+
+  default:
+    break;
+  }
+
+  return r;
+}
+
+
 #define IN_ALT          (1<<0)
 #define IN_NOT          (1<<1)
 #define IN_REAL_REPEAT  (1<<2)
@@ -3559,7 +3973,7 @@ divide_look_behind_alternatives(Node* node)
 
   head = NODE_ANCHOR_BODY(an);
   np = NODE_CAR(head);
-  swap_node(node, head);
+  node_swap(node, head);
   NODE_CAR(node) = head;
   NODE_BODY(head) = np;
 
@@ -3581,7 +3995,7 @@ divide_look_behind_alternatives(Node* node)
 }
 
 static int
-setup_look_behind(Node* node, regex_t* reg, ScanEnv* env)
+tune_look_behind(Node* node, regex_t* reg, ScanEnv* env)
 {
   int r, len;
   AnchorNode* an = ANCHOR_(node);
@@ -3602,7 +4016,7 @@ setup_look_behind(Node* node, regex_t* reg, ScanEnv* env)
 }
 
 static int
-next_setup(Node* node, Node* next_node, regex_t* reg)
+tune_next(Node* node, Node* next_node, regex_t* reg)
 {
   NodeType type;
 
@@ -3629,7 +4043,7 @@ next_setup(Node* node, Node* next_node, regex_t* reg)
               Node* en = onig_node_new_bag(BAG_STOP_BACKTRACK);
               CHECK_NULL_RETURN_MEMERR(en);
               NODE_STATUS_ADD(en, STRICT_REAL_REPEAT);
-              swap_node(node, en);
+              node_swap(node, en);
               NODE_BODY(node) = en;
             }
           }
@@ -3649,23 +4063,57 @@ next_setup(Node* node, Node* next_node, regex_t* reg)
 
 
 static int
-update_string_node_case_fold(regex_t* reg, Node *node)
+is_all_code_len_1_items(int n, OnigCaseFoldCodeItem items[])
 {
-  UChar *p, *end, buf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
+  int i;
+
+  for (i = 0; i < n; i++) {
+    OnigCaseFoldCodeItem* item = items + i;
+    if (item->code_len != 1) return 0;
+  }
+
+  return 1;
+}
+
+static int
+get_min_max_byte_len_case_fold_items(int n, OnigCaseFoldCodeItem items[], int* rmin, int* rmax)
+{
+  int i, len, minlen, maxlen;
+
+  minlen = INT_MAX;
+  maxlen = 0;
+  for (i = 0; i < n; i++) {
+    OnigCaseFoldCodeItem* item = items + i;
+
+    len = item->byte_len;
+    if (len < minlen) minlen = len;
+    if (len > maxlen) maxlen = len;
+  }
+
+  *rmin = minlen;
+  *rmax = maxlen;
+  return 0;
+}
+
+static int
+conv_string_case_fold(OnigEncoding enc, OnigCaseFoldType case_fold_flag,
+           UChar* s, UChar* end, UChar** rs, UChar** rend, int* rcase_min_len)
+{
+  UChar *p, buf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
   UChar *sbuf, *ebuf, *sp;
-  int r, i, len, sbuf_size;
-  StrNode* sn = STR_(node);
+  int i, n, len, sbuf_size;
 
-  end = sn->end;
-  sbuf_size = (int )(end - sn->s) * 2;
+  *rs = NULL;
+  sbuf_size = (int )(end - s) * 2;
   sbuf = (UChar* )xmalloc(sbuf_size);
   CHECK_NULL_RETURN_MEMERR(sbuf);
   ebuf = sbuf + sbuf_size;
 
+  n = 0;
   sp = sbuf;
-  p = sn->s;
+  p = s;
   while (p < end) {
-    len = ONIGENC_MBC_CASE_FOLD(reg->enc, reg->case_fold_flag, &p, end, buf);
+    len = ONIGENC_MBC_CASE_FOLD(enc, case_fold_flag, &p, end, buf);
     for (i = 0; i < len; i++) {
       if (sp >= ebuf) {
         sbuf = (UChar* )xrealloc(sbuf, sbuf_size * 2);
@@ -3677,356 +4125,302 @@ update_string_node_case_fold(regex_t* reg, Node *node)
 
       *sp++ = buf[i];
     }
+    n++;
   }
 
-  r = onig_node_str_set(node, sbuf, sp);
-  if (r != 0) {
-    xfree(sbuf);
-    return r;
-  }
-
-  xfree(sbuf);
+  *rs = sbuf;
+  *rend = sp;
+  *rcase_min_len = n;
   return 0;
 }
 
 static int
-expand_case_fold_make_rem_string(Node** rnode, UChar *s, UChar *end, regex_t* reg)
+make_code_list_to_string(Node** rnode, OnigEncoding enc,
+                         int n, OnigCodePoint codes[])
 {
-  int r;
-  Node *node;
+  int r, i, len;
+  Node* node;
+  UChar buf[ONIGENC_CODE_TO_MBC_MAXLEN];
 
-  node = onig_node_new_str(s, end);
-  if (IS_NULL(node)) return ONIGERR_MEMORY;
+  *rnode = NULL_NODE;
+  node = onig_node_new_str(NULL, NULL);
+  CHECK_NULL_RETURN_MEMERR(node);
 
-  r = update_string_node_case_fold(reg, node);
-  if (r != 0) {
-    onig_node_free(node);
-    return r;
+  for (i = 0; i < n; i++) {
+    len = ONIGENC_CODE_TO_MBC(enc, codes[i], buf);
+    if (len < 0) {
+      r = len;
+      goto err;
+    }
+
+    r = onig_node_str_cat(node, buf, buf + len);
+    if (r != 0) goto err;
   }
 
-  NODE_STRING_SET_AMBIG(node);
-  NODE_STRING_SET_DONT_GET_OPT_INFO(node);
   *rnode = node;
   return 0;
+
+ err:
+  onig_node_free(node);
+  return r;
 }
 
 static int
-expand_case_fold_string_alt(int item_num, OnigCaseFoldCodeItem items[], UChar *p,
-                            int slen, UChar *end, regex_t* reg, Node **rnode)
+unravel_cf_node_add(Node** rlist, Node* add)
 {
-  int r, i, j;
-  int len;
-  int varlen;
-  Node *anode, *var_anode, *snode, *xnode, *an;
-  UChar buf[ONIGENC_CODE_TO_MBC_MAXLEN];
-
-  *rnode = var_anode = NULL_NODE;
+  Node *list;
 
-  varlen = 0;
-  for (i = 0; i < item_num; i++) {
-    if (items[i].byte_len != slen) {
-      varlen = 1;
-      break;
-    }
+  list = *rlist;
+  if (IS_NULL(list)) {
+    list = onig_node_new_list(add, NULL);
+    CHECK_NULL_RETURN_MEMERR(list);
+    *rlist = list;
   }
+  else {
+    Node* r = node_list_add(list, add);
+    CHECK_NULL_RETURN_MEMERR(r);
+  }
+
+  return 0;
+}
 
-  if (varlen != 0) {
-    *rnode = var_anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
-    if (IS_NULL(var_anode)) return ONIGERR_MEMORY;
+static int
+unravel_cf_string_add(Node** rlist, Node** rsn, UChar* s, UChar* end,
+                      unsigned int flag, int case_min_len)
+{
+  int r;
+  Node *sn, *list;
 
-    xnode = onig_node_new_list(NULL, NULL);
-    if (IS_NULL(xnode)) goto mem_err;
-    NODE_CAR(var_anode) = xnode;
+  list = *rlist;
+  sn   = *rsn;
 
-    anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
-    if (IS_NULL(anode)) goto mem_err;
-    NODE_CAR(xnode) = anode;
+  if (IS_NOT_NULL(sn) && STR_(sn)->flag == flag) {
+    if (NODE_STRING_IS_CASE_FOLD_MATCH(sn))
+      r = node_str_cat_case_fold(sn, s, end, case_min_len);
+    else
+      r = onig_node_str_cat(sn, s, end);
   }
   else {
-    *rnode = anode = onig_node_new_alt(NULL_NODE, NULL_NODE);
-    if (IS_NULL(anode)) return ONIGERR_MEMORY;
+    sn = onig_node_new_str(s, end);
+    CHECK_NULL_RETURN_MEMERR(sn);
+
+    STR_(sn)->flag = flag;
+    STR_(sn)->case_min_len = case_min_len;
+    r = unravel_cf_node_add(&list, sn);
   }
 
-  snode = onig_node_new_str(p, p + slen);
-  if (IS_NULL(snode)) goto mem_err;
+  if (r == 0) {
+    *rlist = list;
+    *rsn = sn;
+  }
+  return r;
+}
 
-  NODE_CAR(anode) = snode;
+static int
+unravel_cf_string_fold_add(Node** rlist, Node** rsn, OnigEncoding enc,
+                      OnigCaseFoldType case_fold_flag, UChar* s, UChar* end)
+{
+  int r;
+  int case_min_len;
+  UChar *rs, *rend;
 
-  for (i = 0; i < item_num; i++) {
-    snode = onig_node_new_str(NULL, NULL);
-    if (IS_NULL(snode)) goto mem_err;
+  r = conv_string_case_fold(enc, case_fold_flag, s, end,
+                            &rs, &rend, &case_min_len);
+  if (r != 0) return r;
 
-    for (j = 0; j < items[i].code_len; j++) {
-      len = ONIGENC_CODE_TO_MBC(reg->enc, items[i].code[j], buf);
-      if (len < 0) {
-        r = len;
-        goto mem_err2;
-      }
+  r = unravel_cf_string_add(rlist, rsn, rs, rend,
+                            NODE_STRING_CASE_FOLD_MATCH, case_min_len);
+  xfree(rs);
 
-      r = onig_node_str_cat(snode, buf, buf + len);
-      if (r != 0) goto mem_err2;
-    }
+  return r;
+}
 
-    an = onig_node_new_alt(NULL_NODE, NULL_NODE);
-    if (IS_NULL(an)) {
-      goto mem_err2;
-    }
+static int
+unravel_cf_string_alt_or_cc_add(Node** rlist, int n,
+            OnigCaseFoldCodeItem items[], int byte_len, OnigEncoding enc,
+            OnigCaseFoldType case_fold_flag, UChar* s, UChar* end)
+{
+  int r, i;
+  Node* node;
 
-    if (items[i].byte_len != slen && IS_NOT_NULL(var_anode)) {
-      Node *rem;
-      UChar *q = p + items[i].byte_len;
+  if (is_all_code_len_1_items(n, items)) {
+    OnigCodePoint codes[14];/* least ONIGENC_GET_CASE_FOLD_CODES_MAX_NUM + 1 */
 
-      if (q < end) {
-        r = expand_case_fold_make_rem_string(&rem, q, end, reg);
-        if (r != 0) {
-          onig_node_free(an);
-          goto mem_err2;
-        }
+    codes[0] = ONIGENC_MBC_TO_CODE(enc, s, end);
+    for (i = 0; i < n; i++) {
+      OnigCaseFoldCodeItem* item = items + i;
+      codes[i+1] = item->code[0];
+    }
+    r = onig_new_cclass_with_code_list(&node, enc, n + 1, codes);
+    if (r != 0) return r;
+  }
+  else {
+    Node *snode, *alt, *curr;
 
-        xnode = onig_node_list_add(NULL_NODE, snode);
-        if (IS_NULL(xnode)) {
-          onig_node_free(an);
-          onig_node_free(rem);
-          goto mem_err2;
-        }
-        if (IS_NULL(onig_node_list_add(xnode, rem))) {
-          onig_node_free(an);
-          onig_node_free(xnode);
-          onig_node_free(rem);
-          goto mem_err;
-        }
+    snode = onig_node_new_str(s, end);
+    CHECK_NULL_RETURN_MEMERR(snode);
+    node = curr = onig_node_new_alt(snode, NULL_NODE);
+    if (IS_NULL(curr)) {
+      onig_node_free(snode);
+      return ONIGERR_MEMORY;
+    }
 
-        NODE_CAR(an) = xnode;
+    r = 0;
+    for (i = 0; i < n; i++) {
+      OnigCaseFoldCodeItem* item = items + i;
+      r = make_code_list_to_string(&snode, enc, item->code_len, item->code);
+      if (r != 0) {
+        onig_node_free(node);
+        return r;
       }
-      else {
-        NODE_CAR(an) = snode;
+
+      alt = onig_node_new_alt(snode, NULL_NODE);
+      if (IS_NULL(alt)) {
+        onig_node_free(snode);
+        onig_node_free(node);
+        return ONIGERR_MEMORY;
       }
 
-      NODE_CDR(var_anode) = an;
-      var_anode = an;
-    }
-    else {
-      NODE_CAR(an)     = snode;
-      NODE_CDR(anode) = an;
-      anode = an;
+      NODE_CDR(curr) = alt;
+      curr = alt;
     }
   }
 
-  return varlen;
-
- mem_err2:
-  onig_node_free(snode);
-
- mem_err:
-  onig_node_free(*rnode);
-
-  return ONIGERR_MEMORY;
+  r = unravel_cf_node_add(rlist, node);
+  if (r != 0) onig_node_free(node);
+  return r;
 }
 
 static int
-is_good_case_fold_items_for_search(OnigEncoding enc, int slen,
-                                   int n, OnigCaseFoldCodeItem items[])
+unravel_cf_look_behind_add(Node** rlist, Node** rsn,
+                int n, OnigCaseFoldCodeItem items[], OnigEncoding enc,
+                UChar* s, int one_len)
 {
-  int i, len;
-  UChar buf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
+  int r, i, found;
 
+  found = 0;
   for (i = 0; i < n; i++) {
     OnigCaseFoldCodeItem* item = items + i;
+    if (item->byte_len == one_len) {
+      if (item->code_len == 1) {
+        found = 1;
+      }
+    }
+  }
 
-    if (item->code_len != 1)    return 0;
-    if (item->byte_len != slen) return 0;
-    len = ONIGENC_CODE_TO_MBC(enc, item->code[0], buf);
-    if (len != slen) return 0;
+  if (found == 0) {
+    r = unravel_cf_string_add(rlist, rsn, s, s + one_len, 0 /* flag */, 0);
   }
+  else {
+    Node* node;
+    OnigCodePoint codes[14];/* least ONIGENC_GET_CASE_FOLD_CODES_MAX_NUM + 1 */
 
-  return 1;
-}
+    found = 0;
+    codes[found++] = ONIGENC_MBC_TO_CODE(enc, s, s + one_len);
+    for (i = 0; i < n; i++) {
+      OnigCaseFoldCodeItem* item = items + i;
+      if (item->byte_len == one_len) {
+        if (item->code_len == 1) {
+          codes[found++] = item->code[0];
+        }
+      }
+    }
+    r = onig_new_cclass_with_code_list(&node, enc, found, codes);
+    if (r != 0) return r;
 
-#define THRESHOLD_CASE_FOLD_ALT_FOR_EXPANSION  8
+    r = unravel_cf_node_add(rlist, node);
+    if (r != 0) onig_node_free(node);
+
+    *rsn = NULL_NODE;
+  }
+
+  return r;
+}
 
 static int
-expand_case_fold_string(Node* node, regex_t* reg, int state)
-{
-  int r, n, len, alt_num;
-  int fold_len;
-  int prev_is_ambig, prev_is_good, is_good, is_in_look_behind;
-  UChar *start, *end, *p;
-  UChar* foldp;
-  Node *top_root, *root, *snode, *prev_node;
+unravel_case_fold_string(Node* node, regex_t* reg, int state)
+{
+  int r, n, one_len, min_len, max_len, in_look_behind;
+  UChar *start, *end, *p, *q;
+  StrNode* snode;
+  Node *sn, *list;
+  OnigEncoding enc;
   OnigCaseFoldCodeItem items[ONIGENC_GET_CASE_FOLD_CODES_MAX_NUM];
-  UChar buf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
-  StrNode* sn;
 
-  if (NODE_STRING_IS_AMBIG(node)) return 0;
+  if (NODE_STRING_IS_CASE_EXPANDED(node)) return 0;
 
-  sn = STR_(node);
+  snode = STR_(node);
 
-  start = sn->s;
-  end   = sn->end;
+  start = snode->s;
+  end   = snode->end;
   if (start >= end) return 0;
 
-  is_in_look_behind = (state & IN_LOOK_BEHIND) != 0;
+  in_look_behind = (state & IN_LOOK_BEHIND) != 0;
+  enc = reg->enc;
 
-  r = 0;
-  top_root = root = prev_node = snode = NULL_NODE;
-  alt_num = 1;
+  list = sn = NULL_NODE;
   p = start;
   while (p < end) {
-    n = ONIGENC_GET_CASE_FOLD_CODES_BY_STR(reg->enc, reg->case_fold_flag,
-                                           p, end, items);
+    n = ONIGENC_GET_CASE_FOLD_CODES_BY_STR(enc, reg->case_fold_flag, p, end,
+                                           items);
     if (n < 0) {
       r = n;
       goto err;
     }
 
-    len = enclen(reg->enc, p);
-    is_good = is_good_case_fold_items_for_search(reg->enc, len, n, items);
-
-    if (is_in_look_behind ||
-        (IS_NOT_NULL(snode) ||
-         (is_good
-          /* expand single char case: ex. /(?i:a)/ */
-          && !(p == start && p + len >= end)))) {
-      if (IS_NULL(snode)) {
-        if (IS_NULL(root) && IS_NOT_NULL(prev_node)) {
-          top_root = root = onig_node_list_add(NULL_NODE, prev_node);
-          if (IS_NULL(root)) {
-            onig_node_free(prev_node);
-            goto mem_err;
-          }
-        }
-
-        prev_node = snode = onig_node_new_str(NULL, NULL);
-        if (IS_NULL(snode)) goto mem_err;
-        if (IS_NOT_NULL(root)) {
-          if (IS_NULL(onig_node_list_add(root, snode))) {
-            onig_node_free(snode);
-            goto mem_err;
-          }
-        }
-
-        prev_is_ambig = -1; /* -1: new */
-        prev_is_good  =  0; /* escape compiler warning */
-      }
-      else {
-        prev_is_ambig = NODE_STRING_IS_AMBIG(snode);
-        prev_is_good  = NODE_STRING_IS_GOOD_AMBIG(snode);
-      }
-
-      if (n != 0) {
-        foldp = p;
-        fold_len = ONIGENC_MBC_CASE_FOLD(reg->enc, reg->case_fold_flag,
-                                         &foldp, end, buf);
-        foldp = buf;
-      }
-      else {
-        foldp = p; fold_len = len;
-      }
-
-      if ((prev_is_ambig == 0 && n != 0) ||
-          (prev_is_ambig > 0 && (n == 0 || prev_is_good != is_good))) {
-        if (IS_NULL(root) /* && IS_NOT_NULL(prev_node) */) {
-          top_root = root = onig_node_list_add(NULL_NODE, prev_node);
-          if (IS_NULL(root)) {
-            onig_node_free(prev_node);
-            goto mem_err;
-          }
-        }
-
-        prev_node = snode = onig_node_new_str(foldp, foldp + fold_len);
-        if (IS_NULL(snode)) goto mem_err;
-        if (IS_NULL(onig_node_list_add(root, snode))) {
-          onig_node_free(snode);
-          goto mem_err;
-        }
-      }
-      else {
-        r = onig_node_str_cat(snode, foldp, foldp + fold_len);
-        if (r != 0) goto err;
-      }
-
-      if (n != 0) NODE_STRING_SET_AMBIG(snode);
-      if (is_good != 0) NODE_STRING_SET_GOOD_AMBIG(snode);
+    one_len = enclen(enc, p);
+    if (n == 0) {
+      q = p + one_len;
+      r = unravel_cf_string_add(&list, &sn, p, q, 0 /* flag */, 0);
+      if (r != 0) goto err;
     }
     else {
-      alt_num *= (n + 1);
-      if (alt_num > THRESHOLD_CASE_FOLD_ALT_FOR_EXPANSION) break;
-
-      if (IS_NULL(root) && IS_NOT_NULL(prev_node)) {
-        top_root = root = onig_node_list_add(NULL_NODE, prev_node);
-        if (IS_NULL(root)) {
-          onig_node_free(prev_node);
-          goto mem_err;
-        }
+      if (in_look_behind != 0) {
+        q = p + one_len;
+        r = unravel_cf_look_behind_add(&list, &sn, n, items, enc, p, one_len);
+        if (r != 0) goto err;
       }
-
-      r = expand_case_fold_string_alt(n, items, p, len, end, reg, &prev_node);
-      if (r < 0) goto mem_err;
-      if (r == 1) {
-        if (IS_NULL(root)) {
-          top_root = prev_node;
+      else {
+        get_min_max_byte_len_case_fold_items(n, items, &min_len, &max_len);
+        q = p + max_len;
+        if (one_len == max_len && min_len == max_len) {
+          r = unravel_cf_string_alt_or_cc_add(&list, n, items, max_len, enc,
+                                              reg->case_fold_flag, p, q);
+          if (r != 0) goto err;
+          sn = NULL_NODE;
         }
         else {
-          if (IS_NULL(onig_node_list_add(root, prev_node))) {
-            onig_node_free(prev_node);
-            goto mem_err;
-          }
-        }
-
-        root = NODE_CAR(prev_node);
-      }
-      else { /* r == 0 */
-        if (IS_NOT_NULL(root)) {
-          if (IS_NULL(onig_node_list_add(root, prev_node))) {
-            onig_node_free(prev_node);
-            goto mem_err;
-          }
+          r = unravel_cf_string_fold_add(&list, &sn, enc, reg->case_fold_flag,
+                                         p, q);
+          if (r != 0) goto err;
         }
       }
-
-      snode = NULL_NODE;
     }
 
-    p += len;
+    p = q;
   }
 
-  if (p < end) {
-    Node *srem;
-
-    r = expand_case_fold_make_rem_string(&srem, p, end, reg);
-    if (r != 0) goto mem_err;
-
-    if (IS_NOT_NULL(prev_node) && IS_NULL(root)) {
-      top_root = root = onig_node_list_add(NULL_NODE, prev_node);
-      if (IS_NULL(root)) {
-        onig_node_free(srem);
-        onig_node_free(prev_node);
-        goto mem_err;
-      }
-    }
-
-    if (IS_NULL(root)) {
-      prev_node = srem;
+  if (IS_NOT_NULL(list)) {
+    if (node_list_len(list) == 1) {
+      node_swap(node, NODE_CAR(list));
     }
     else {
-      if (IS_NULL(onig_node_list_add(root, srem))) {
-        onig_node_free(srem);
-        goto mem_err;
-      }
+      node_swap(node, list);
     }
+    onig_node_free(list);
+  }
+  else {
+    node_swap(node, sn);
+    onig_node_free(sn);
   }
-
-  /* ending */
-  top_root = (IS_NOT_NULL(top_root) ? top_root : prev_node);
-  swap_node(node, top_root);
-  onig_node_free(top_root);
   return 0;
 
- mem_err:
-  r = ONIGERR_MEMORY;
-
  err:
-  onig_node_free(top_root);
+  if (IS_NOT_NULL(list))
+    onig_node_free(list);
+  else if (IS_NOT_NULL(sn))
+    onig_node_free(sn);
+
   return r;
 }
 
@@ -4121,7 +4515,7 @@ quantifiers_memory_node_info(Node* node)
 __inline
 #endif
 static int
-setup_call_node_call(CallNode* cn, ScanEnv* env, int state)
+tune_call_node_call(CallNode* cn, ScanEnv* env, int state)
 {
   MemEnv* mem_env = SCANENV_MEMENV(env);
 
@@ -4141,7 +4535,7 @@ setup_call_node_call(CallNode* cn, ScanEnv* env, int state)
     }
 
   set_call_attr:
-    NODE_CALL_BODY(cn) = mem_env[cn->group_num].node;
+    NODE_CALL_BODY(cn) = mem_env[cn->group_num].mem_node;
     if (IS_NULL(NODE_CALL_BODY(cn))) {
       onig_scan_env_set_error_string(env, ONIGERR_UNDEFINED_NAME_REFERENCE,
                                      cn->name, cn->name_end);
@@ -4172,23 +4566,23 @@ setup_call_node_call(CallNode* cn, ScanEnv* env, int state)
 }
 
 static void
-setup_call2_call(Node* node)
+tune_call2_call(Node* node)
 {
   switch (NODE_TYPE(node)) {
   case NODE_LIST:
   case NODE_ALT:
     do {
-      setup_call2_call(NODE_CAR(node));
+      tune_call2_call(NODE_CAR(node));
     } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
   case NODE_QUANT:
-    setup_call2_call(NODE_BODY(node));
+    tune_call2_call(NODE_BODY(node));
     break;
 
   case NODE_ANCHOR:
     if (ANCHOR_HAS_BODY(ANCHOR_(node)))
-      setup_call2_call(NODE_BODY(node));
+      tune_call2_call(NODE_BODY(node));
     break;
 
   case NODE_BAG:
@@ -4198,19 +4592,19 @@ setup_call2_call(Node* node)
       if (en->type == BAG_MEMORY) {
         if (! NODE_IS_MARK1(node)) {
           NODE_STATUS_ADD(node, MARK1);
-          setup_call2_call(NODE_BODY(node));
+          tune_call2_call(NODE_BODY(node));
           NODE_STATUS_REMOVE(node, MARK1);
         }
       }
       else if (en->type == BAG_IF_ELSE) {
-        setup_call2_call(NODE_BODY(node));
+        tune_call2_call(NODE_BODY(node));
         if (IS_NOT_NULL(en->te.Then))
-          setup_call2_call(en->te.Then);
+          tune_call2_call(en->te.Then);
         if (IS_NOT_NULL(en->te.Else))
-          setup_call2_call(en->te.Else);
+          tune_call2_call(en->te.Else);
       }
       else {
-        setup_call2_call(NODE_BODY(node));
+        tune_call2_call(NODE_BODY(node));
       }
     }
     break;
@@ -4226,7 +4620,7 @@ setup_call2_call(Node* node)
 
         NODE_STATUS_ADD(called, CALLED);
         BAG_(called)->m.entry_count++;
-        setup_call2_call(called);
+        tune_call2_call(called);
       }
       NODE_STATUS_REMOVE(node, MARK1);
     }
@@ -4238,7 +4632,7 @@ setup_call2_call(Node* node)
 }
 
 static int
-setup_call(Node* node, ScanEnv* env, int state)
+tune_call(Node* node, ScanEnv* env, int state)
 {
   int r;
 
@@ -4246,7 +4640,7 @@ setup_call(Node* node, ScanEnv* env, int state)
   case NODE_LIST:
   case NODE_ALT:
     do {
-      r = setup_call(NODE_CAR(node), env, state);
+      r = tune_call(NODE_CAR(node), env, state);
     } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
@@ -4254,12 +4648,12 @@ setup_call(Node* node, ScanEnv* env, int state)
     if (QUANT_(node)->upper == 0)
       state |= IN_ZERO_REPEAT;
 
-    r = setup_call(NODE_BODY(node), env, state);
+    r = tune_call(NODE_BODY(node), env, state);
     break;
 
   case NODE_ANCHOR:
     if (ANCHOR_HAS_BODY(ANCHOR_(node)))
-      r = setup_call(NODE_BODY(node), env, state);
+      r = tune_call(NODE_BODY(node), env, state);
     else
       r = 0;
     break;
@@ -4273,20 +4667,20 @@ setup_call(Node* node, ScanEnv* env, int state)
           NODE_STATUS_ADD(node, IN_ZERO_REPEAT);
           BAG_(node)->m.entry_count--;
         }
-        r = setup_call(NODE_BODY(node), env, state);
+        r = tune_call(NODE_BODY(node), env, state);
       }
       else if (en->type == BAG_IF_ELSE) {
-        r = setup_call(NODE_BODY(node), env, state);
+        r = tune_call(NODE_BODY(node), env, state);
         if (r != 0) return r;
         if (IS_NOT_NULL(en->te.Then)) {
-          r = setup_call(en->te.Then, env, state);
+          r = tune_call(en->te.Then, env, state);
           if (r != 0) return r;
         }
         if (IS_NOT_NULL(en->te.Else))
-          r = setup_call(en->te.Else, env, state);
+          r = tune_call(en->te.Else, env, state);
       }
       else
-        r = setup_call(NODE_BODY(node), env, state);
+        r = tune_call(NODE_BODY(node), env, state);
     }
     break;
 
@@ -4296,7 +4690,7 @@ setup_call(Node* node, ScanEnv* env, int state)
       CALL_(node)->entry_count--;
     }
 
-    r = setup_call_node_call(CALL_(node), env, state);
+    r = tune_call_node_call(CALL_(node), env, state);
     break;
 
   default:
@@ -4308,7 +4702,7 @@ setup_call(Node* node, ScanEnv* env, int state)
 }
 
 static int
-setup_call2(Node* node)
+tune_call2(Node* node)
 {
   int r = 0;
 
@@ -4316,23 +4710,23 @@ setup_call2(Node* node)
   case NODE_LIST:
   case NODE_ALT:
     do {
-      r = setup_call2(NODE_CAR(node));
+      r = tune_call2(NODE_CAR(node));
     } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
   case NODE_QUANT:
     if (QUANT_(node)->upper != 0)
-      r = setup_call2(NODE_BODY(node));
+      r = tune_call2(NODE_BODY(node));
     break;
 
   case NODE_ANCHOR:
     if (ANCHOR_HAS_BODY(ANCHOR_(node)))
-      r = setup_call2(NODE_BODY(node));
+      r = tune_call2(NODE_BODY(node));
     break;
 
   case NODE_BAG:
     if (! NODE_IS_IN_ZERO_REPEAT(node))
-      r = setup_call2(NODE_BODY(node));
+      r = tune_call2(NODE_BODY(node));
 
     {
       BagNode* en = BAG_(node);
@@ -4340,18 +4734,18 @@ setup_call2(Node* node)
       if (r != 0) return r;
       if (en->type == BAG_IF_ELSE) {
         if (IS_NOT_NULL(en->te.Then)) {
-          r = setup_call2(en->te.Then);
+          r = tune_call2(en->te.Then);
           if (r != 0) return r;
         }
         if (IS_NOT_NULL(en->te.Else))
-          r = setup_call2(en->te.Else);
+          r = tune_call2(en->te.Else);
       }
     }
     break;
 
   case NODE_CALL:
     if (! NODE_IS_IN_ZERO_REPEAT(node)) {
-      setup_call2_call(node);
+      tune_call2_call(node);
     }
     break;
 
@@ -4364,7 +4758,7 @@ setup_call2(Node* node)
 
 
 static void
-setup_called_state_call(Node* node, int state)
+tune_called_state_call(Node* node, int state)
 {
   switch (NODE_TYPE(node)) {
   case NODE_ALT:
@@ -4372,7 +4766,7 @@ setup_called_state_call(Node* node, int state)
     /* fall */
   case NODE_LIST:
     do {
-      setup_called_state_call(NODE_CAR(node), state);
+      tune_called_state_call(NODE_CAR(node), state);
     } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
@@ -4385,7 +4779,7 @@ setup_called_state_call(Node* node, int state)
       if (qn->lower != qn->upper)
         state |= IN_VAR_REPEAT;
 
-      setup_called_state_call(NODE_QUANT_BODY(qn), state);
+      tune_called_state_call(NODE_QUANT_BODY(qn), state);
     }
     break;
 
@@ -4400,7 +4794,7 @@ setup_called_state_call(Node* node, int state)
         /* fall */
       case ANCR_PREC_READ:
       case ANCR_LOOK_BEHIND:
-        setup_called_state_call(NODE_ANCHOR_BODY(an), state);
+        tune_called_state_call(NODE_ANCHOR_BODY(an), state);
         break;
       default:
         break;
@@ -4416,31 +4810,33 @@ setup_called_state_call(Node* node, int state)
         if (NODE_IS_MARK1(node)) {
           if ((~en->m.called_state & state) != 0) {
             en->m.called_state |= state;
-            setup_called_state_call(NODE_BODY(node), state);
+            tune_called_state_call(NODE_BODY(node), state);
           }
         }
         else {
           NODE_STATUS_ADD(node, MARK1);
           en->m.called_state |= state;
-          setup_called_state_call(NODE_BODY(node), state);
+          tune_called_state_call(NODE_BODY(node), state);
           NODE_STATUS_REMOVE(node, MARK1);
         }
       }
       else if (en->type == BAG_IF_ELSE) {
+        state |= IN_ALT;
+        tune_called_state_call(NODE_BODY(node), state);
         if (IS_NOT_NULL(en->te.Then)) {
-          setup_called_state_call(en->te.Then, state);
+          tune_called_state_call(en->te.Then, state);
         }
         if (IS_NOT_NULL(en->te.Else))
-          setup_called_state_call(en->te.Else, state);
+          tune_called_state_call(en->te.Else, state);
       }
       else {
-        setup_called_state_call(NODE_BODY(node), state);
+        tune_called_state_call(NODE_BODY(node), state);
       }
     }
     break;
 
   case NODE_CALL:
-    setup_called_state_call(NODE_BODY(node), state);
+    tune_called_state_call(NODE_BODY(node), state);
     break;
 
   default:
@@ -4449,7 +4845,7 @@ setup_called_state_call(Node* node, int state)
 }
 
 static void
-setup_called_state(Node* node, int state)
+tune_called_state(Node* node, int state)
 {
   switch (NODE_TYPE(node)) {
   case NODE_ALT:
@@ -4457,13 +4853,13 @@ setup_called_state(Node* node, int state)
     /* fall */
   case NODE_LIST:
     do {
-      setup_called_state(NODE_CAR(node), state);
+      tune_called_state(NODE_CAR(node), state);
     } while (IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
 #ifdef USE_CALL
   case NODE_CALL:
-    setup_called_state_call(node, state);
+    tune_called_state_call(node, state);
     break;
 #endif
 
@@ -4480,14 +4876,15 @@ setup_called_state(Node* node, int state)
         /* fall */
       case BAG_OPTION:
       case BAG_STOP_BACKTRACK:
-        setup_called_state(NODE_BODY(node), state);
+        tune_called_state(NODE_BODY(node), state);
         break;
       case BAG_IF_ELSE:
-        setup_called_state(NODE_BODY(node), state);
+        state |= IN_ALT;
+        tune_called_state(NODE_BODY(node), state);
         if (IS_NOT_NULL(en->te.Then))
-          setup_called_state(en->te.Then, state);
+          tune_called_state(en->te.Then, state);
         if (IS_NOT_NULL(en->te.Else))
-          setup_called_state(en->te.Else, state);
+          tune_called_state(en->te.Else, state);
         break;
       }
     }
@@ -4502,7 +4899,7 @@ setup_called_state(Node* node, int state)
       if (qn->lower != qn->upper)
         state |= IN_VAR_REPEAT;
 
-      setup_called_state(NODE_QUANT_BODY(qn), state);
+      tune_called_state(NODE_QUANT_BODY(qn), state);
     }
     break;
 
@@ -4517,7 +4914,7 @@ setup_called_state(Node* node, int state)
         /* fall */
       case ANCR_PREC_READ:
       case ANCR_LOOK_BEHIND:
-        setup_called_state(NODE_ANCHOR_BODY(an), state);
+        tune_called_state(NODE_ANCHOR_BODY(an), state);
         break;
       default:
         break;
@@ -4538,13 +4935,13 @@ setup_called_state(Node* node, int state)
 #endif  /* USE_CALL */
 
 
-static int setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env);
+static int tune_tree(Node* node, regex_t* reg, int state, ScanEnv* env);
 
 #ifdef __GNUC__
 __inline
 #endif
 static int
-setup_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
+tune_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
 {
 /* allowed node types in look-behind */
 #define ALLOWED_TYPE_IN_LB \
@@ -4572,10 +4969,10 @@ setup_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
 
   switch (an->type) {
   case ANCR_PREC_READ:
-    r = setup_tree(NODE_ANCHOR_BODY(an), reg, state, env);
+    r = tune_tree(NODE_ANCHOR_BODY(an), reg, state, env);
     break;
   case ANCR_PREC_READ_NOT:
-    r = setup_tree(NODE_ANCHOR_BODY(an), reg, (state | IN_NOT), env);
+    r = tune_tree(NODE_ANCHOR_BODY(an), reg, (state | IN_NOT), env);
     break;
 
   case ANCR_LOOK_BEHIND:
@@ -4584,9 +4981,9 @@ setup_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
                           ALLOWED_BAG_IN_LB, ALLOWED_ANCHOR_IN_LB);
       if (r < 0) return r;
       if (r > 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
-      r = setup_tree(NODE_ANCHOR_BODY(an), reg, (state|IN_LOOK_BEHIND), env);
+      r = tune_tree(NODE_ANCHOR_BODY(an), reg, (state|IN_LOOK_BEHIND), env);
       if (r != 0) return r;
-      r = setup_look_behind(node, reg, env);
+      r = tune_look_behind(node, reg, env);
     }
     break;
 
@@ -4596,10 +4993,10 @@ setup_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
                           ALLOWED_BAG_IN_LB_NOT, ALLOWED_ANCHOR_IN_LB_NOT);
       if (r < 0) return r;
       if (r > 0) return ONIGERR_INVALID_LOOK_BEHIND_PATTERN;
-      r = setup_tree(NODE_ANCHOR_BODY(an), reg, (state|IN_NOT|IN_LOOK_BEHIND),
-                     env);
+      r = tune_tree(NODE_ANCHOR_BODY(an), reg, (state|IN_NOT|IN_LOOK_BEHIND),
+                    env);
       if (r != 0) return r;
-      r = setup_look_behind(node, reg, env);
+      r = tune_look_behind(node, reg, env);
     }
     break;
 
@@ -4615,7 +5012,7 @@ setup_anchor(Node* node, regex_t* reg, int state, ScanEnv* env)
 __inline
 #endif
 static int
-setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
+tune_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
 {
   int r;
   OnigLen d;
@@ -4634,12 +5031,6 @@ setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
     if (d == 0) {
 #ifdef USE_STUBBORN_CHECK_CAPTURES_IN_EMPTY_REPEAT
       qn->emptiness = quantifiers_memory_node_info(body);
-      if (qn->emptiness == BODY_IS_EMPTY_POSSIBILITY_REC) {
-        if (NODE_TYPE(body) == NODE_BAG &&
-            BAG_(body)->type == BAG_MEMORY) {
-          MEM_STATUS_ON(env->bt_mem_end, BAG_(body)->m.regnum);
-        }
-      }
 #else
       qn->emptiness = BODY_IS_EMPTY_POSSIBILITY;
 #endif
@@ -4651,7 +5042,7 @@ setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
   if (qn->lower != qn->upper)
     state |= IN_VAR_REPEAT;
 
-  r = setup_tree(body, reg, state, env);
+  r = tune_tree(body, reg, state, env);
   if (r != 0) return r;
 
   /* expand string */
@@ -4660,13 +5051,12 @@ setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
     if (!IS_INFINITE_REPEAT(qn->lower) && qn->lower == qn->upper &&
         qn->lower > 1 && qn->lower <= EXPAND_STRING_MAX_LENGTH) {
       int len = NODE_STRING_LEN(body);
-      StrNode* sn = STR_(body);
 
       if (len * qn->lower <= EXPAND_STRING_MAX_LENGTH) {
         int i, n = qn->lower;
-        onig_node_conv_to_str_node(node, STR_(body)->flag);
+        node_conv_to_str_node(node, STR_(body)->flag);
         for (i = 0; i < n; i++) {
-          r = onig_node_str_cat(node, sn->s, sn->end);
+          r = node_str_node_cat(node, body);
           if (r != 0) return r;
         }
         onig_node_free(body);
@@ -4691,7 +5081,7 @@ setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
   return r;
 }
 
-/* setup_tree does the following work.
+/* tune_tree does the following work.
  1. check empty loop. (set qn->emptiness)
  2. expand ignore-case in char class.
  3. set memory status bit flags. (reg->mem_stats)
@@ -4700,7 +5090,7 @@ setup_quant(Node* node, regex_t* reg, int state, ScanEnv* env)
  6. expand repeated string.
  */
 static int
-setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
+tune_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
 {
   int r = 0;
 
@@ -4709,9 +5099,9 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
     {
       Node* prev = NULL_NODE;
       do {
-        r = setup_tree(NODE_CAR(node), reg, state, env);
+        r = tune_tree(NODE_CAR(node), reg, state, env);
         if (IS_NOT_NULL(prev) && r == 0) {
-          r = next_setup(prev, NODE_CAR(node), reg);
+          r = tune_next(prev, NODE_CAR(node), reg);
         }
         prev = NODE_CAR(node);
       } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
@@ -4720,13 +5110,13 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
 
   case NODE_ALT:
     do {
-      r = setup_tree(NODE_CAR(node), reg, (state | IN_ALT), env);
+      r = tune_tree(NODE_CAR(node), reg, (state | IN_ALT), env);
     } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
     break;
 
   case NODE_STRING:
-    if (IS_IGNORECASE(reg->options) && !NODE_STRING_IS_RAW(node)) {
-      r = expand_case_fold_string(node, reg, state);
+    if (IS_IGNORECASE(reg->options) && !NODE_STRING_IS_CRUDE(node)) {
+      r = unravel_case_fold_string(node, reg, state);
     }
     break;
 
@@ -4739,12 +5129,18 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
       for (i = 0; i < br->back_num; i++) {
         if (p[i] > env->num_mem)  return ONIGERR_INVALID_BACKREF;
         MEM_STATUS_ON(env->backrefed_mem, p[i]);
-        MEM_STATUS_ON(env->bt_mem_start, p[i]);
+#if 0
 #ifdef USE_BACKREF_WITH_LEVEL
         if (NODE_IS_NEST_LEVEL(node)) {
-          MEM_STATUS_ON(env->bt_mem_end, p[i]);
+          MEM_STATUS_ON(env->backtrack_mem, p[i]);
         }
 #endif
+#else
+        /* More precisely, it should be checked whether alt/repeat exists before
+           the subject capture node, and then this backreference position
+           exists before (or in) the capture node. */
+        MEM_STATUS_ON(env->backtrack_mem, p[i]);
+#endif
       }
     }
     break;
@@ -4758,7 +5154,7 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
         {
           OnigOptionType options = reg->options;
           reg->options = BAG_(node)->o.options;
-          r = setup_tree(NODE_BODY(node), reg, state, env);
+          r = tune_tree(NODE_BODY(node), reg, state, env);
           reg->options = options;
         }
         break;
@@ -4770,15 +5166,15 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
 
         if ((state & (IN_ALT | IN_NOT | IN_VAR_REPEAT | IN_MULTI_ENTRY)) != 0
             || NODE_IS_RECURSION(node)) {
-          MEM_STATUS_ON(env->bt_mem_start, en->m.regnum);
+          MEM_STATUS_ON(env->backtrack_mem, en->m.regnum);
         }
-        r = setup_tree(NODE_BODY(node), reg, state, env);
+        r = tune_tree(NODE_BODY(node), reg, state, env);
         break;
 
       case BAG_STOP_BACKTRACK:
         {
           Node* target = NODE_BODY(node);
-          r = setup_tree(target, reg, state, env);
+          r = tune_tree(target, reg, state, env);
           if (NODE_TYPE(target) == NODE_QUANT) {
             QuantNode* tqn = QUANT_(target);
             if (IS_INFINITE_REPEAT(tqn->upper) && tqn->lower <= 1 &&
@@ -4791,25 +5187,25 @@ setup_tree(Node* node, regex_t* reg, int state, ScanEnv* env)
         break;
 
       case BAG_IF_ELSE:
-        r = setup_tree(NODE_BODY(node), reg, (state | IN_ALT), env);
+        r = tune_tree(NODE_BODY(node), reg, (state | IN_ALT), env);
         if (r != 0) return r;
         if (IS_NOT_NULL(en->te.Then)) {
-          r = setup_tree(en->te.Then, reg, (state | IN_ALT), env);
+          r = tune_tree(en->te.Then, reg, (state | IN_ALT), env);
           if (r != 0) return r;
         }
         if (IS_NOT_NULL(en->te.Else))
-          r = setup_tree(en->te.Else, reg, (state | IN_ALT), env);
+          r = tune_tree(en->te.Else, reg, (state | IN_ALT), env);
         break;
       }
     }
     break;
 
   case NODE_QUANT:
-    r = setup_quant(node, reg, state, env);
+    r = tune_quant(node, reg, state, env);
     break;
 
   case NODE_ANCHOR:
-    r = setup_anchor(node, reg, state, env);
+    r = tune_anchor(node, reg, state, env);
     break;
 
 #ifdef USE_CALL
@@ -4908,7 +5304,7 @@ typedef struct {
 } MinMax;
 
 typedef struct {
-  MinMax           mmd;
+  MinMax           mm;
   OnigEncoding     enc;
   OnigOptionType   options;
   OnigCaseFoldType case_fold_flag;
@@ -4921,17 +5317,16 @@ typedef struct {
 } OptAnc;
 
 typedef struct {
-  MinMax     mmd;   /* position */
+  MinMax     mm;   /* position */
   OptAnc     anc;
   int        reach_end;
   int        case_fold;
-  int        good_case_fold;
   int        len;
   UChar      s[OPT_EXACT_MAXLEN];
 } OptStr;
 
 typedef struct {
-  MinMax    mmd;    /* position */
+  MinMax    mm;     /* position */
   OptAnc    anc;
   int       value;  /* weighted value */
   UChar     map[CHAR_MAP_SIZE];
@@ -5148,11 +5543,10 @@ is_full_opt_exact(OptStr* e)
 static void
 clear_opt_exact(OptStr* e)
 {
-  clear_mml(&e->mmd);
+  clear_mml(&e->mm);
   clear_opt_anc_info(&e->anc);
   e->reach_end      = 0;
   e->case_fold      = 0;
-  e->good_case_fold = 0;
   e->len            = 0;
   e->s[0]           = '\0';
 }
@@ -5176,11 +5570,6 @@ concat_opt_exact(OptStr* to, OptStr* add, OnigEncoding enc)
 
       to->case_fold = 1;
     }
-    else {
-      if (to->good_case_fold != 0) {
-        if (add->good_case_fold == 0) return 0;
-      }
-    }
   }
 
   r = 0;
@@ -5235,7 +5624,7 @@ alt_merge_opt_exact(OptStr* to, OptStr* add, OptEnv* env)
     return ;
   }
 
-  if (! is_equal_mml(&to->mmd, &add->mmd)) {
+  if (! is_equal_mml(&to->mm, &add->mm)) {
     clear_opt_exact(to);
     return ;
   }
@@ -5257,8 +5646,6 @@ alt_merge_opt_exact(OptStr* to, OptStr* add, OptEnv* env)
   to->len = i;
   if (add->case_fold != 0)
     to->case_fold = 1;
-  if (add->good_case_fold == 0)
-    to->good_case_fold = 0;
 
   alt_merge_opt_anc_info(&to->anc, &add->anc);
   if (! to->reach_end) to->anc.right = 0;
@@ -5291,10 +5678,7 @@ select_opt_exact(OnigEncoding enc, OptStr* now, OptStr* alt)
   if (now->case_fold == 0) vn *= 2;
   if (alt->case_fold == 0) va *= 2;
 
-  if (now->good_case_fold != 0) vn *= 4;
-  if (alt->good_case_fold != 0) va *= 4;
-
-  if (comp_distance_value(&now->mmd, &alt->mmd, vn, va) > 0)
+  if (comp_distance_value(&now->mm, &alt->mm, vn, va) > 0)
     copy_opt_exact(now, alt);
 }
 
@@ -5378,7 +5762,7 @@ select_opt_map(OptMap* now, OptMap* alt)
 
   vn = z / now->value;
   va = z / alt->value;
-  if (comp_distance_value(&now->mmd, &alt->mmd, vn, va) > 0)
+  if (comp_distance_value(&now->mm, &alt->mm, vn, va) > 0)
     copy_opt_map(now, alt);
 }
 
@@ -5392,17 +5776,14 @@ comp_opt_exact_or_map(OptStr* e, OptMap* m)
   if (m->value <= 0) return -1;
 
   if (e->case_fold != 0) {
-    if (e->good_case_fold != 0)
-      case_value = 2;
-    else
-      case_value = 1;
+    case_value = 1;
   }
   else
     case_value = 3;
 
   ae = COMP_EM_BASE * e->len * case_value;
   am = COMP_EM_BASE * 5 * 2 / m->value;
-  return comp_distance_value(&e->mmd, &m->mmd, ae, am);
+  return comp_distance_value(&e->mm, &m->mm, ae, am);
 }
 
 static void
@@ -5410,14 +5791,14 @@ alt_merge_opt_map(OnigEncoding enc, OptMap* to, OptMap* add)
 {
   int i, val;
 
-  /* if (! is_equal_mml(&to->mmd, &add->mmd)) return ; */
+  /* if (! is_equal_mml(&to->mm, &add->mm)) return ; */
   if (to->value == 0) return ;
-  if (add->value == 0 || to->mmd.max < add->mmd.min) {
+  if (add->value == 0 || to->mm.max < add->mm.min) {
     clear_opt_map(to);
     return ;
   }
 
-  alt_merge_mml(&to->mmd, &add->mmd);
+  alt_merge_mml(&to->mm, &add->mm);
 
   val = 0;
   for (i = 0; i < CHAR_MAP_SIZE; i++) {
@@ -5435,9 +5816,9 @@ alt_merge_opt_map(OnigEncoding enc, OptMap* to, OptMap* add)
 static void
 set_bound_node_opt_info(OptNode* opt, MinMax* plen)
 {
-  copy_mml(&(opt->sb.mmd),  plen);
-  copy_mml(&(opt->spr.mmd), plen);
-  copy_mml(&(opt->map.mmd), plen);
+  copy_mml(&(opt->sb.mm),  plen);
+  copy_mml(&(opt->spr.mm), plen);
+  copy_mml(&(opt->map.mm), plen);
 }
 
 static void
@@ -5472,7 +5853,7 @@ concat_left_node_opt_info(OnigEncoding enc, OptNode* to, OptNode* add)
   }
 
   if (add->map.value > 0 && to->len.max == 0) {
-    if (add->map.mmd.max == 0)
+    if (add->map.mm.max == 0)
       add->map.anc.left |= to->anc.left;
   }
 
@@ -5497,10 +5878,7 @@ concat_left_node_opt_info(OnigEncoding enc, OptNode* to, OptNode* add)
 
   if (to->spr.len > 0) {
     if (add->len.max > 0) {
-      if (to->spr.len > (int )add->len.max)
-        to->spr.len = add->len.max;
-
-      if (to->spr.mmd.max == 0)
+      if (to->spr.mm.max == 0)
         select_opt_exact(enc, &to->sb, &to->spr);
       else
         select_opt_exact(enc, &to->sm, &to->spr);
@@ -5540,7 +5918,7 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
   r = 0;
   enc = env->enc;
   clear_node_opt_info(opt);
-  set_bound_node_opt_info(opt, &env->mmd);
+  set_bound_node_opt_info(opt, &env->mm);
 
   switch (NODE_TYPE(node)) {
   case NODE_LIST:
@@ -5552,7 +5930,7 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
       do {
         r = optimize_nodes(NODE_CAR(nd), &xo, &nenv);
         if (r == 0) {
-          add_mml(&nenv.mmd, &xo.len);
+          add_mml(&nenv.mm, &xo.len);
           concat_left_node_opt_info(enc, opt, &xo);
         }
       } while (r == 0 && IS_NOT_NULL(nd = NODE_CDR(nd)));
@@ -5577,9 +5955,8 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
     {
       StrNode* sn = STR_(node);
       int slen = (int )(sn->end - sn->s);
-      /* int is_raw = NODE_STRING_IS_RAW(node); */
 
-      if (! NODE_STRING_IS_AMBIG(node)) {
+      if (! NODE_STRING_IS_CASE_FOLD_MATCH(node)) {
         concat_opt_exact_str(&opt->sb, sn->s, sn->end, enc);
         if (slen > 0) {
           add_char_opt_map(&opt->map, *(sn->s), enc);
@@ -5587,28 +5964,20 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
         set_mml(&opt->len, slen, slen);
       }
       else {
-        int max;
+        int max, min;
 
-        if (NODE_STRING_IS_DONT_GET_OPT_INFO(node)) {
-          int n = onigenc_strlen(enc, sn->s, sn->end);
-          max = ONIGENC_MBC_MAXLEN_DIST(enc) * n;
-        }
-        else {
-          concat_opt_exact_str(&opt->sb, sn->s, sn->end, enc);
-          opt->sb.case_fold = 1;
-          if (NODE_STRING_IS_GOOD_AMBIG(node))
-            opt->sb.good_case_fold = 1;
-
-          if (slen > 0) {
-            r = add_char_amb_opt_map(&opt->map, sn->s, sn->end,
-                                     enc, env->case_fold_flag);
-            if (r != 0) break;
-          }
+        concat_opt_exact_str(&opt->sb, sn->s, sn->end, enc);
+        opt->sb.case_fold = 1;
 
-          max = slen;
+        if (slen > 0) {
+          r = add_char_amb_opt_map(&opt->map, sn->s, sn->end,
+                                   enc, env->case_fold_flag);
+          if (r != 0) break;
         }
 
-        set_mml(&opt->len, slen, max);
+        max = slen;
+        min = sn->case_min_len * ONIGENC_MBC_MINLEN(enc);
+        set_mml(&opt->len, min, max);
       }
     }
     break;
@@ -5618,7 +5987,7 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
       int z;
       CClassNode* cc = CCLASS_(node);
 
-      /* no need to check ignore case. (set in setup_tree()) */
+      /* no need to check ignore case. (set in tune_tree()) */
 
       if (IS_NOT_NULL(cc->mbuf) || IS_NCCLASS_NOT(cc)) {
         OnigLen min = ONIGENC_MBC_MINLEN(enc);
@@ -5728,11 +6097,11 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
         break;
       }
       backs = BACKREFS_P(br);
-      min = tree_min_len(mem_env[backs[0]].node, env->scan_env);
-      max = tree_max_len(mem_env[backs[0]].node, env->scan_env);
+      min = tree_min_len(mem_env[backs[0]].mem_node, env->scan_env);
+      max = tree_max_len(mem_env[backs[0]].mem_node, env->scan_env);
       for (i = 1; i < br->back_num; i++) {
-        tmin = tree_min_len(mem_env[backs[i]].node, env->scan_env);
-        tmax = tree_max_len(mem_env[backs[i]].node, env->scan_env);
+        tmin = tree_min_len(mem_env[backs[i]].mem_node, env->scan_env);
+        tmax = tree_max_len(mem_env[backs[i]].mem_node, env->scan_env);
         if (min > tmin) min = tmin;
         if (max < tmax) max = tmax;
       }
@@ -5782,7 +6151,7 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
       }
 
       if (IS_INFINITE_REPEAT(qn->upper)) {
-        if (env->mmd.max == 0 &&
+        if (env->mm.max == 0 &&
             NODE_IS_ANYCHAR(NODE_BODY(node)) && qn->greedy != 0) {
           if (IS_MULTILINE(CTYPE_OPTION(NODE_QUANT_BODY(qn), env)))
             add_opt_anc_info(&opt->anc, ANCR_ANYCHAR_INF_ML);
@@ -5850,7 +6219,7 @@ optimize_nodes(Node* node, OptNode* opt, OptEnv* env)
           copy_opt_env(&nenv, env);
           r = optimize_nodes(NODE_BAG_BODY(en), &xo, &nenv);
           if (r == 0) {
-            add_mml(&nenv.mmd, &xo.len);
+            add_mml(&nenv.mm, &xo.len);
             concat_left_node_opt_info(enc, opt, &xo);
             if (IS_NOT_NULL(en->te.Then)) {
               r = optimize_nodes(en->te.Then, &xo, &nenv);
@@ -5899,15 +6268,6 @@ set_optimize_exact(regex_t* reg, OptStr* e)
 
   if (e->case_fold) {
     reg->optimize = OPTIMIZE_STR_CASE_FOLD;
-    if (e->good_case_fold != 0) {
-      if (e->len >= 2) {
-        r = set_sunday_quick_search_or_bmh_skip_table(reg, 1,
-                             reg->exact, reg->exact_end,
-                             reg->map, &(reg->map_offset));
-        if (r != 0) return r;
-        reg->optimize = OPTIMIZE_STR_CASE_FOLD_FAST;
-      }
-    }
   }
   else {
     int allow_reverse;
@@ -5930,11 +6290,17 @@ set_optimize_exact(regex_t* reg, OptStr* e)
     }
   }
 
-  reg->dmin = e->mmd.min;
-  reg->dmax = e->mmd.max;
+  reg->dist_min = e->mm.min;
+  reg->dist_max = e->mm.max;
 
-  if (reg->dmin != INFINITE_LEN) {
-    reg->threshold_len = reg->dmin + (int )(reg->exact_end - reg->exact);
+  if (reg->dist_min != INFINITE_LEN) {
+    int n;
+    if (e->case_fold != 0)
+      n = 1;
+    else
+      n = (int )(reg->exact_end - reg->exact);
+
+    reg->threshold_len = reg->dist_min + n;
   }
 
   return 0;
@@ -5949,11 +6315,11 @@ set_optimize_map(regex_t* reg, OptMap* m)
     reg->map[i] = m->map[i];
 
   reg->optimize   = OPTIMIZE_MAP;
-  reg->dmin       = m->mmd.min;
-  reg->dmax       = m->mmd.max;
+  reg->dist_min   = m->mm.min;
+  reg->dist_max   = m->mm.max;
 
-  if (reg->dmin != INFINITE_LEN) {
-    reg->threshold_len = reg->dmin + 1;
+  if (reg->dist_min != INFINITE_LEN) {
+    reg->threshold_len = reg->dist_min + 1;
   }
 }
 
@@ -5979,7 +6345,7 @@ set_optimize_info_from_tree(Node* node, regex_t* reg, ScanEnv* scan_env)
   env.options        = reg->options;
   env.case_fold_flag = reg->case_fold_flag;
   env.scan_env       = scan_env;
-  clear_mml(&env.mmd);
+  clear_mml(&env.mm);
 
   r = optimize_nodes(node, &opt, &env);
   if (r != 0) return r;
@@ -5995,8 +6361,8 @@ set_optimize_info_from_tree(Node* node, regex_t* reg, ScanEnv* scan_env)
                                   ANCR_PREC_READ_NOT);
 
   if (reg->anchor & (ANCR_END_BUF | ANCR_SEMI_END_BUF)) {
-    reg->anchor_dmin = opt.len.min;
-    reg->anchor_dmax = opt.len.max;
+    reg->anc_dist_min = opt.len.min;
+    reg->anc_dist_max = opt.len.max;
   }
 
   if (opt.sb.len > 0 || opt.sm.len > 0) {
@@ -6031,8 +6397,8 @@ clear_optimize_info(regex_t* reg)
 {
   reg->optimize      = OPTIMIZE_NONE;
   reg->anchor        = 0;
-  reg->anchor_dmin   = 0;
-  reg->anchor_dmax   = 0;
+  reg->anc_dist_min  = 0;
+  reg->anc_dist_max  = 0;
   reg->sub_anchor    = 0;
   reg->exact_end     = (UChar* )NULL;
   reg->map_offset    = 0;
@@ -6151,12 +6517,12 @@ print_optimize_info(FILE* f, regex_t* reg)
 {
   static const char* on[] = { "NONE", "STR",
                               "STR_FAST", "STR_FAST_STEP_FORWARD",
-                              "STR_CASE_FOLD_FAST", "STR_CASE_FOLD", "MAP" };
+                              "STR_CASE_FOLD", "MAP" };
 
   fprintf(f, "optimize: %s\n", on[reg->optimize]);
   fprintf(f, "  anchor: "); print_anchor(f, reg->anchor);
   if ((reg->anchor & ANCR_END_BUF_MASK) != 0)
-    print_distance_range(f, reg->anchor_dmin, reg->anchor_dmax);
+    print_distance_range(f, reg->anc_dist_min, reg->anc_dist_max);
   fprintf(f, "\n");
 
   if (reg->optimize) {
@@ -6304,7 +6670,7 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   Node*  root;
   ScanEnv  scan_env;
 #ifdef USE_CALL
-  UnsetAddrList  uslist;
+  UnsetAddrList  uslist = {0};
 #endif
 
   root = 0;
@@ -6328,13 +6694,17 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
   reg->string_pool_end    = 0;
   reg->num_mem            = 0;
   reg->num_repeat         = 0;
-  reg->num_null_check     = 0;
+  reg->num_empty_check    = 0;
   reg->repeat_range_alloc = 0;
-  reg->repeat_range       = (OnigRepeatRange* )NULL;
+  reg->repeat_range       = (RepeatRange* )NULL;
+  reg->empty_status_mem   = 0;
 
   r = onig_parse_tree(&root, pattern, pattern_end, reg, &scan_env);
   if (r != 0) goto err;
 
+  r = reduce_string_list(root);
+  if (r != 0) goto err;
+
   /* mixed use named group and no-named group */
   if (scan_env.num_named > 0 &&
       IS_SYNTAX_BV(scan_env.syntax, ONIG_SYN_CAPTURE_ONLY_NAMED_GROUP) &&
@@ -6355,38 +6725,65 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
     r = unset_addr_list_init(&uslist, scan_env.num_call);
     if (r != 0) goto err;
     scan_env.unset_addr_list = &uslist;
-    r = setup_call(root, &scan_env, 0);
+    r = tune_call(root, &scan_env, 0);
     if (r != 0) goto err_unset;
-    r = setup_call2(root);
+    r = tune_call2(root);
     if (r != 0) goto err_unset;
     r = recursive_call_check_trav(root, &scan_env, 0);
     if (r  < 0) goto err_unset;
     r = infinite_recursive_call_check_trav(root, &scan_env);
     if (r != 0) goto err_unset;
 
-    setup_called_state(root, 0);
+    tune_called_state(root, 0);
   }
 
   reg->num_call = scan_env.num_call;
 #endif
 
-  r = setup_tree(root, reg, 0, &scan_env);
+#ifdef ONIG_DEBUG_PARSE
+  fprintf(stderr, "MAX PARSE DEPTH: %d\n", scan_env.max_parse_depth);
+  fprintf(stderr, "TREE (parsed)\n");
+  print_tree(stderr, root);
+  fprintf(stderr, "\n");
+#endif
+
+  r = tune_tree(root, reg, 0, &scan_env);
   if (r != 0) goto err_unset;
 
+  if (scan_env.backref_num != 0) {
+    set_parent_node_trav(root, NULL_NODE);
+    r = set_empty_repeat_node_trav(root, NULL_NODE, &scan_env);
+    if (r != 0) goto err_unset;
+    set_empty_status_check_trav(root, &scan_env);
+  }
+
 #ifdef ONIG_DEBUG_PARSE
+  fprintf(stderr, "TREE (after tune)\n");
   print_tree(stderr, root);
+  fprintf(stderr, "\n");
 #endif
 
-  reg->capture_history  = scan_env.capture_history;
-  reg->bt_mem_start     = scan_env.bt_mem_start;
-  reg->bt_mem_start    |= reg->capture_history;
-  if (IS_FIND_CONDITION(reg->options))
-    MEM_STATUS_ON_ALL(reg->bt_mem_end);
+  reg->capture_history  = scan_env.cap_history;
+  reg->push_mem_start   = scan_env.backtrack_mem | scan_env.cap_history;
+
+#ifdef USE_CALLOUT
+  if (IS_NOT_NULL(reg->extp) && reg->extp->callout_num != 0) {
+    reg->push_mem_end = reg->push_mem_start;
+  }
   else {
-    reg->bt_mem_end  = scan_env.bt_mem_end;
-    reg->bt_mem_end |= reg->capture_history;
+    if (MEM_STATUS_IS_ALL_ON(reg->push_mem_start))
+      reg->push_mem_end = scan_env.backrefed_mem | scan_env.cap_history;
+    else
+      reg->push_mem_end = reg->push_mem_start &
+                        (scan_env.backrefed_mem | scan_env.cap_history);
   }
-  reg->bt_mem_start |= reg->bt_mem_end;
+#else
+  if (MEM_STATUS_IS_ALL_ON(reg->push_mem_start))
+    reg->push_mem_end = scan_env.backrefed_mem | scan_env.cap_history;
+  else
+    reg->push_mem_end = reg->push_mem_start &
+                      (scan_env.backrefed_mem | scan_env.cap_history);
+#endif
 
   clear_optimize_info(reg);
 #ifndef ONIG_DONT_OPTIMIZE
@@ -6420,14 +6817,20 @@ onig_compile(regex_t* reg, const UChar* pattern, const UChar* pattern_end,
     }
 #endif
 
-    if ((reg->num_repeat != 0) || (reg->bt_mem_end != 0)
+    set_addr_in_repeat_range(reg);
+
+    if ((reg->push_mem_end != 0)
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+        || (reg->num_repeat      != 0)
+        || (reg->num_empty_check != 0)
+#endif
 #ifdef USE_CALLOUT
         || (IS_NOT_NULL(reg->extp) && reg->extp->callout_num != 0)
 #endif
         )
       reg->stack_pop_level = STACK_POP_LEVEL_ALL;
     else {
-      if (reg->bt_mem_start != 0)
+      if (reg->push_mem_start != 0)
         reg->stack_pop_level = STACK_POP_LEVEL_MEM_START;
       else
         reg->stack_pop_level = STACK_POP_LEVEL_FREE;
@@ -6560,11 +6963,14 @@ onig_new(regex_t** reg, const UChar* pattern, const UChar* pattern_end,
   if (IS_NULL(*reg)) return ONIGERR_MEMORY;
 
   r = onig_reg_init(*reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
-  if (r != 0) goto err;
+  if (r != 0) {
+    xfree(*reg);
+    *reg = NULL;
+    return r;
+  }
 
   r = onig_compile(*reg, pattern, pattern_end, einfo);
   if (r != 0) {
-  err:
     onig_free(*reg);
     *reg = NULL;
   }
@@ -6709,12 +7115,14 @@ onig_is_code_in_cc(OnigEncoding enc, OnigCodePoint code, CClassNode* cc)
 
 #ifdef ONIG_DEBUG_PARSE
 
+#ifdef USE_CALL
 static void
 p_string(FILE* f, int len, UChar* s)
 {
   fputs(":", f);
   while (len-- > 0) { fputc(*s++, f); }
 }
+#endif
 
 static void
 Indent(FILE* f, int indent)
@@ -6734,7 +7142,7 @@ print_indent_tree(FILE* f, Node* node, int indent)
   Indent(f, indent);
   if (IS_NULL(node)) {
     fprintf(f, "ERROR: null node!!!\n");
-    exit (0);
+    exit(0);
   }
 
   type = NODE_TYPE(node);
@@ -6758,28 +7166,22 @@ print_indent_tree(FILE* f, Node* node, int indent)
 
   case NODE_STRING:
     {
+      char* str;
       char* mode;
-      char* dont;
-      char* good;
 
-      if (NODE_STRING_IS_RAW(node))
-        mode = "-raw";
-      else if (NODE_STRING_IS_AMBIG(node))
-        mode = "-ambig";
+      if (NODE_STRING_IS_CRUDE(node))
+        mode = "-crude";
+      else if (NODE_STRING_IS_CASE_FOLD_MATCH(node))
+        mode = "-case_fold_match";
       else
         mode = "";
 
-      if (NODE_STRING_IS_GOOD_AMBIG(node))
-        good = "-good";
+      if (STR_(node)->s == STR_(node)->end)
+        str = "empty-string";
       else
-        good = "";
+        str = "string";
 
-      if (NODE_STRING_IS_DONT_GET_OPT_INFO(node))
-        dont = " (dont-opt)";
-      else
-        dont = "";
-
-      fprintf(f, "<string%s%s%s:%p>", mode, good, dont, node);
+      fprintf(f, "<%s%s:%p>", str, mode, node);
       for (p = STR_(node)->s; p < STR_(node)->end; p++) {
         if (*p >= 0x20 && *p < 0x7f)
           fputc(*p, f);
@@ -6901,6 +7303,34 @@ print_indent_tree(FILE* f, Node* node, int indent)
 
   case NODE_BAG:
     fprintf(f, "<bag:%p> ", node);
+    if (BAG_(node)->type == BAG_IF_ELSE) {
+      Node* Then;
+      Node* Else;
+      BagNode* bn;
+
+      bn = BAG_(node);
+      fprintf(f, "if-else\n");
+      print_indent_tree(f, NODE_BODY(node), indent + add);
+
+      Then = bn->te.Then;
+      Else = bn->te.Else;
+      if (IS_NULL(Then)) {
+        Indent(f, indent + add);
+        fprintf(f, "THEN empty\n");
+      }
+      else
+        print_indent_tree(f, Then, indent + add);
+
+      if (IS_NULL(Else)) {
+        Indent(f, indent + add);
+        fprintf(f, "ELSE empty\n");
+      }
+      else
+        print_indent_tree(f, Else, indent + add);
+
+      break;
+    }
+
     switch (BAG_(node)->type) {
     case BAG_OPTION:
       fprintf(f, "option:%d", BAG_(node)->o.options);
@@ -6911,8 +7341,7 @@ print_indent_tree(FILE* f, Node* node, int indent)
     case BAG_STOP_BACKTRACK:
       fprintf(f, "stop-bt");
       break;
-    case BAG_IF_ELSE:
-      fprintf(f, "if-else");
+    default:
       break;
     }
     fprintf(f, "\n");
diff --git a/src/regenc.c b/src/regenc.c
index 9fab721..16ac313 100644
--- a/src/regenc.c
+++ b/src/regenc.c
@@ -2,7 +2,7 @@
   regenc.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -182,7 +182,8 @@ onigenc_get_right_adjust_char_head_with_prev(OnigEncoding enc,
     p += enclen(enc, p);
   }
   else {
-    if (prev) *prev = (const UChar* )NULL; /* Sorry */
+    if (prev)
+      *prev = onigenc_get_prev_char_head(enc, start, p);
   }
   return p;
 }
@@ -208,20 +209,6 @@ onigenc_step_back(OnigEncoding enc, const UChar* start, const UChar* s, int n)
   return (UChar* )s;
 }
 
-#if 0
-extern int
-onigenc_mbc_enc_len_end(OnigEncoding enc, const UChar* p, const UChar* end)
-{
-  int len;
-  int n;
-
-  len = ONIGENC_MBC_ENC_LEN(enc, p);
-  n = (int )(end - p);
-
-  return (n < len ? n : len);
-}
-#endif
-
 extern UChar*
 onigenc_step(OnigEncoding enc, const UChar* p, const UChar* end, int n)
 {
@@ -705,18 +692,6 @@ onigenc_ascii_mbc_case_fold(OnigCaseFoldType flag ARG_UNUSED, const UChar** p,
   return 1; /* return byte length of converted char to lower */
 }
 
-#if 0
-extern int
-onigenc_ascii_is_mbc_ambiguous(OnigCaseFoldType flag,
-                               const UChar** pp, const UChar* end)
-{
-  const UChar* p = *pp;
-
-  (*pp)++;
-  return ONIGENC_IS_ASCII_CODE_CASE_AMBIG(*p);
-}
-#endif
-
 extern int
 onigenc_single_byte_mbc_enc_len(const UChar* p ARG_UNUSED)
 {
@@ -833,41 +808,6 @@ onigenc_mbn_mbc_case_fold(OnigEncoding enc, OnigCaseFoldType flag ARG_UNUSED,
   }
 }
 
-#if 0
-extern int
-onigenc_mbn_is_mbc_ambiguous(OnigEncoding enc, OnigCaseFoldType flag,
-                             const UChar** pp, const UChar* end)
-{
-  const UChar* p = *pp;
-
-  if (ONIGENC_IS_MBC_ASCII(p)) {
-    (*pp)++;
-    return ONIGENC_IS_ASCII_CODE_CASE_AMBIG(*p);
-  }
-
-  (*pp) += enclen(enc, p);
-  return FALSE;
-}
-#endif
-
-extern int
-onigenc_mb2_code_to_mbclen(OnigCodePoint code)
-{
-  if ((code & (~0xffff)) != 0) return ONIGERR_INVALID_CODE_POINT_VALUE;
-
-  if ((code & 0xff00) != 0) return 2;
-  else return 1;
-}
-
-extern int
-onigenc_mb4_code_to_mbclen(OnigCodePoint code)
-{
-       if ((code & 0xff000000) != 0) return 4;
-  else if ((code & 0xff0000) != 0) return 3;
-  else if ((code & 0xff00) != 0) return 2;
-  else return 1;
-}
-
 extern int
 onigenc_mb2_code_to_mbc(OnigEncoding enc, OnigCodePoint code, UChar *buf)
 {
diff --git a/src/regenc.h b/src/regenc.h
index bd2819e..db35841 100644
--- a/src/regenc.h
+++ b/src/regenc.h
@@ -4,7 +4,7 @@
   regenc.h -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -163,13 +163,11 @@ extern int onigenc_length_check_is_valid_mbc_string P_((OnigEncoding enc, const
 /* methods for multi byte encoding */
 extern OnigCodePoint onigenc_mbn_mbc_to_code P_((OnigEncoding enc, const UChar* p, const UChar* end));
 extern int onigenc_mbn_mbc_case_fold P_((OnigEncoding enc, OnigCaseFoldType flag, const UChar** p, const UChar* end, UChar* lower));
-extern int onigenc_mb2_code_to_mbclen P_((OnigCodePoint code));
 extern int onigenc_mb2_code_to_mbc P_((OnigEncoding enc, OnigCodePoint code, UChar *buf));
 extern int onigenc_minimum_property_name_to_ctype P_((OnigEncoding enc, UChar* p, UChar* end));
 extern int onigenc_unicode_property_name_to_ctype P_((OnigEncoding enc, UChar* p, UChar* end));
 extern int onigenc_is_mbc_word_ascii P_((OnigEncoding enc, UChar* s, const UChar* end));
 extern int onigenc_mb2_is_code_ctype P_((OnigEncoding enc, OnigCodePoint code, unsigned int ctype));
-extern int onigenc_mb4_code_to_mbclen P_((OnigCodePoint code));
 extern int onigenc_mb4_code_to_mbc P_((OnigEncoding enc, OnigCodePoint code, UChar *buf));
 extern int onigenc_mb4_is_code_ctype P_((OnigEncoding enc, OnigCodePoint code, unsigned int ctype));
 extern struct PropertyNameCtype* onigenc_euc_jp_lookup_property_name P_((register const char *str, register size_t len));
diff --git a/src/regerror.c b/src/regerror.c
index e6d1806..b57a276 100644
--- a/src/regerror.c
+++ b/src/regerror.c
@@ -2,7 +2,7 @@
   regerror.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/regexec.c b/src/regexec.c
index f957b75..ce498c6 100644
--- a/src/regexec.c
+++ b/src/regexec.c
@@ -2,7 +2,7 @@
   regexec.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -39,6 +39,20 @@
 
 #define CHECK_INTERRUPT_IN_MATCH
 
+#define STACK_MEM_START(reg, i) \
+  (MEM_STATUS_AT((reg)->push_mem_start, (i)) != 0 ? \
+   STACK_AT(mem_start_stk[i])->u.mem.pstr : (UChar* )((void* )(mem_start_stk[i])))
+
+#define STACK_MEM_END(reg, i) \
+  (MEM_STATUS_AT((reg)->push_mem_end, (i)) != 0 ? \
+   STACK_AT(mem_end_stk[i])->u.mem.pstr : (UChar* )((void* )(mem_end_stk[i])))
+
+static int forward_search(regex_t* reg, const UChar* str, const UChar* end, UChar* start, UChar* range, UChar** low, UChar** high, UChar** low_prev);
+
+static int
+search_in_range(regex_t* reg, const UChar* str, const UChar* end, const UChar* start, const UChar* range, /* match range */ const UChar* data_range, /* subject string range */ OnigRegion* region, OnigOptionType option, OnigMatchParam* mp);
+
+
 #ifdef USE_CALLOUT
 typedef struct {
   int last_match_at_call_counter;
@@ -129,7 +143,7 @@ typedef struct {
 } MatchArg;
 
 
-#ifdef ONIG_DEBUG
+#if defined(ONIG_DEBUG_COMPILE) || defined(ONIG_DEBUG_MATCH)
 
 /* arguments type */
 typedef enum {
@@ -149,102 +163,108 @@ typedef struct {
 } OpInfoType;
 
 static OpInfoType OpInfo[] = {
-  { OP_FINISH,            "finish" },
-  { OP_END,               "end"    },
-  { OP_EXACT1,            "exact1" },
-  { OP_EXACT2,            "exact2" },
-  { OP_EXACT3,            "exact3" },
-  { OP_EXACT4,            "exact4" },
-  { OP_EXACT5,            "exact5" },
-  { OP_EXACTN,            "exactn" },
-  { OP_EXACTMB2N1,        "exactmb2-n1" },
-  { OP_EXACTMB2N2,        "exactmb2-n2" },
-  { OP_EXACTMB2N3,        "exactmb2-n3" },
-  { OP_EXACTMB2N,         "exactmb2-n"  },
-  { OP_EXACTMB3N,         "exactmb3n"   },
-  { OP_EXACTMBN,          "exactmbn"    },
-  { OP_EXACT1_IC,         "exact1-ic"   },
-  { OP_EXACTN_IC,         "exactn-ic"   },
-  { OP_CCLASS,            "cclass"      },
-  { OP_CCLASS_MB,         "cclass-mb"   },
-  { OP_CCLASS_MIX,        "cclass-mix"  },
-  { OP_CCLASS_NOT,        "cclass-not"  },
-  { OP_CCLASS_MB_NOT,     "cclass-mb-not"  },
-  { OP_CCLASS_MIX_NOT,    "cclass-mix-not" },
-  { OP_ANYCHAR,               "anychar"     },
-  { OP_ANYCHAR_ML,            "anychar-ml"  },
-  { OP_ANYCHAR_STAR,          "anychar*"    },
-  { OP_ANYCHAR_ML_STAR,       "anychar-ml*" },
-  { OP_ANYCHAR_STAR_PEEK_NEXT,    "anychar*-peek-next" },
-  { OP_ANYCHAR_ML_STAR_PEEK_NEXT, "anychar-ml*-peek-next" },
-  { OP_WORD,                  "word"       },
-  { OP_WORD_ASCII,            "word-ascii" },
-  { OP_NO_WORD,               "not-word"   },
-  { OP_NO_WORD_ASCII,         "not-word-ascii" },
-  { OP_WORD_BOUNDARY,         "word-boundary"  },
-  { OP_NO_WORD_BOUNDARY,      "not-word-boundary" },
-  { OP_WORD_BEGIN,            "word-begin" },
-  { OP_WORD_END,              "word-end"   },
-  { OP_TEXT_SEGMENT_BOUNDARY, "text-segment-boundary" },
-  { OP_BEGIN_BUF,             "begin-buf"  },
-  { OP_END_BUF,               "end-buf"    },
-  { OP_BEGIN_LINE,            "begin-line" },
-  { OP_END_LINE,              "end-line"   },
-  { OP_SEMI_END_BUF,          "semi-end-buf"   },
-  { OP_BEGIN_POSITION,        "begin-position" },
-  { OP_BACKREF1,              "backref1"       },
-  { OP_BACKREF2,              "backref2"       },
-  { OP_BACKREF_N,             "backref-n"      },
-  { OP_BACKREF_N_IC,          "backref-n-ic"   },
-  { OP_BACKREF_MULTI,         "backref_multi"  },
-  { OP_BACKREF_MULTI_IC,      "backref_multi-ic"     },
-  { OP_BACKREF_WITH_LEVEL,    "backref_with_level"   },
-  { OP_BACKREF_WITH_LEVEL_IC, "backref_with_level-c" },
-  { OP_BACKREF_CHECK,         "backref_check"        },
-  { OP_BACKREF_CHECK_WITH_LEVEL, "backref_check_with_level" },
-  { OP_MEMORY_START_PUSH,     "mem-start-push"        },
-  { OP_MEMORY_START,          "mem-start"             },
-  { OP_MEMORY_END_PUSH,       "mem-end-push"          },
-  { OP_MEMORY_END_PUSH_REC,   "mem-end-push-rec"      },
-  { OP_MEMORY_END,            "mem-end"               },
-  { OP_MEMORY_END_REC,        "mem-end-rec"           },
-  { OP_FAIL,                  "fail"                  },
-  { OP_JUMP,                  "jump"                  },
-  { OP_PUSH,                  "push"                  },
-  { OP_PUSH_SUPER,            "push-super"            },
-  { OP_POP_OUT,               "pop-out"               },
+  { OP_FINISH,         "finish"},
+  { OP_END,            "end"},
+  { OP_STR_1,          "str_1"},
+  { OP_STR_2,          "str_2"},
+  { OP_STR_3,          "str_3"},
+  { OP_STR_4,          "str_4"},
+  { OP_STR_5,          "str_5"},
+  { OP_STR_N,          "str_n"},
+  { OP_STR_MB2N1,      "str_mb2-n1"},
+  { OP_STR_MB2N2,      "str_mb2-n2"},
+  { OP_STR_MB2N3,      "str_mb2-n3"},
+  { OP_STR_MB2N,       "str_mb2-n"},
+  { OP_STR_MB3N,       "str_mb3n"},
+  { OP_STR_MBN,        "str_mbn"},
+  { OP_STR_1_IC,       "str_1-ic"},
+  { OP_STR_N_IC,       "str_n-ic"},
+  { OP_CCLASS,         "cclass"},
+  { OP_CCLASS_MB,      "cclass-mb"},
+  { OP_CCLASS_MIX,     "cclass-mix"},
+  { OP_CCLASS_NOT,     "cclass-not"},
+  { OP_CCLASS_MB_NOT,  "cclass-mb-not"},
+  { OP_CCLASS_MIX_NOT, "cclass-mix-not"},
+  { OP_ANYCHAR,               "anychar"},
+  { OP_ANYCHAR_ML,            "anychar-ml"},
+  { OP_ANYCHAR_STAR,          "anychar*"},
+  { OP_ANYCHAR_ML_STAR,       "anychar-ml*"},
+  { OP_ANYCHAR_STAR_PEEK_NEXT,    "anychar*-peek-next"},
+  { OP_ANYCHAR_ML_STAR_PEEK_NEXT, "anychar-ml*-peek-next"},
+  { OP_WORD,                  "word"},
+  { OP_WORD_ASCII,            "word-ascii"},
+  { OP_NO_WORD,               "not-word"},
+  { OP_NO_WORD_ASCII,         "not-word-ascii"},
+  { OP_WORD_BOUNDARY,         "word-boundary"},
+  { OP_NO_WORD_BOUNDARY,      "not-word-boundary"},
+  { OP_WORD_BEGIN,            "word-begin"},
+  { OP_WORD_END,              "word-end"},
+  { OP_TEXT_SEGMENT_BOUNDARY, "text-segment-boundary"},
+  { OP_BEGIN_BUF,             "begin-buf"},
+  { OP_END_BUF,               "end-buf"},
+  { OP_BEGIN_LINE,            "begin-line"},
+  { OP_END_LINE,              "end-line"},
+  { OP_SEMI_END_BUF,          "semi-end-buf"},
+  { OP_BEGIN_POSITION,        "begin-position"},
+  { OP_BACKREF1,              "backref1"},
+  { OP_BACKREF2,              "backref2"},
+  { OP_BACKREF_N,             "backref-n"},
+  { OP_BACKREF_N_IC,          "backref-n-ic"},
+  { OP_BACKREF_MULTI,         "backref_multi"},
+  { OP_BACKREF_MULTI_IC,      "backref_multi-ic"},
+  { OP_BACKREF_WITH_LEVEL,    "backref_with_level"},
+  { OP_BACKREF_WITH_LEVEL_IC, "backref_with_level-c"},
+  { OP_BACKREF_CHECK,         "backref_check"},
+  { OP_BACKREF_CHECK_WITH_LEVEL, "backref_check_with_level"},
+  { OP_MEM_START_PUSH,        "mem-start-push"},
+  { OP_MEM_START,             "mem-start"},
+  { OP_MEM_END_PUSH,          "mem-end-push"},
+#ifdef USE_CALL
+  { OP_MEM_END_PUSH_REC,      "mem-end-push-rec"},
+#endif
+  { OP_MEM_END,               "mem-end"},
+#ifdef USE_CALL
+  { OP_MEM_END_REC,           "mem-end-rec"},
+#endif
+  { OP_FAIL,                  "fail"},
+  { OP_JUMP,                  "jump"},
+  { OP_PUSH,                  "push"},
+  { OP_PUSH_SUPER,            "push-super"},
+  { OP_POP_OUT,               "pop-out"},
 #ifdef USE_OP_PUSH_OR_JUMP_EXACT
-  { OP_PUSH_OR_JUMP_EXACT1,   "push-or-jump-e1"       },
+  { OP_PUSH_OR_JUMP_EXACT1,   "push-or-jump-e1"},
+#endif
+  { OP_PUSH_IF_PEEK_NEXT,     "push-if-peek-next"},
+  { OP_REPEAT,                "repeat"},
+  { OP_REPEAT_NG,             "repeat-ng"},
+  { OP_REPEAT_INC,            "repeat-inc"},
+  { OP_REPEAT_INC_NG,         "repeat-inc-ng"},
+  { OP_EMPTY_CHECK_START,     "empty-check-start"},
+  { OP_EMPTY_CHECK_END,       "empty-check-end"},
+  { OP_EMPTY_CHECK_END_MEMST, "empty-check-end-memst"},
+#ifdef USE_CALL
+  { OP_EMPTY_CHECK_END_MEMST_PUSH,"empty-check-end-memst-push"},
+#endif
+  { OP_PREC_READ_START,       "push-pos"},
+  { OP_PREC_READ_END,         "pop-pos"},
+  { OP_PREC_READ_NOT_START,   "prec-read-not-start"},
+  { OP_PREC_READ_NOT_END,     "prec-read-not-end"},
+  { OP_ATOMIC_START,          "atomic-start"},
+  { OP_ATOMIC_END,            "atomic-end"},
+  { OP_LOOK_BEHIND,           "look-behind"},
+  { OP_LOOK_BEHIND_NOT_START, "look-behind-not-start"},
+  { OP_LOOK_BEHIND_NOT_END,   "look-behind-not-end"},
+  { OP_PUSH_SAVE_VAL,         "push-save-val"},
+  { OP_UPDATE_VAR,            "update-var"},
+#ifdef USE_CALL
+  { OP_CALL,                  "call"},
+  { OP_RETURN,                "return"},
 #endif
-  { OP_PUSH_IF_PEEK_NEXT,     "push-if-peek-next"     },
-  { OP_REPEAT,                "repeat"                },
-  { OP_REPEAT_NG,             "repeat-ng"             },
-  { OP_REPEAT_INC,            "repeat-inc"            },
-  { OP_REPEAT_INC_NG,         "repeat-inc-ng"         },
-  { OP_REPEAT_INC_SG,         "repeat-inc-sg"         },
-  { OP_REPEAT_INC_NG_SG,      "repeat-inc-ng-sg"      },
-  { OP_EMPTY_CHECK_START,     "empty-check-start"     },
-  { OP_EMPTY_CHECK_END,       "empty-check-end"       },
-  { OP_EMPTY_CHECK_END_MEMST, "empty-check-end-memst" },
-  { OP_EMPTY_CHECK_END_MEMST_PUSH,"empty-check-end-memst-push" },
-  { OP_PREC_READ_START,       "push-pos"              },
-  { OP_PREC_READ_END,         "pop-pos"               },
-  { OP_PREC_READ_NOT_START,   "prec-read-not-start"   },
-  { OP_PREC_READ_NOT_END,     "prec-read-not-end"     },
-  { OP_ATOMIC_START,          "atomic-start"          },
-  { OP_ATOMIC_END,            "atomic-end"            },
-  { OP_LOOK_BEHIND,           "look-behind"           },
-  { OP_LOOK_BEHIND_NOT_START, "look-behind-not-start" },
-  { OP_LOOK_BEHIND_NOT_END,   "look-behind-not-end"   },
-  { OP_CALL,                  "call"                  },
-  { OP_RETURN,                "return"                },
-  { OP_PUSH_SAVE_VAL,         "push-save-val"         },
-  { OP_UPDATE_VAR,            "update-var"            },
 #ifdef USE_CALLOUT
-  { OP_CALLOUT_CONTENTS,      "callout-contents"      },
-  { OP_CALLOUT_NAME,          "callout-name"          },
+  { OP_CALLOUT_CONTENTS,      "callout-contents"},
+  { OP_CALLOUT_NAME,          "callout-name"},
 #endif
-  { -1, "" }
+  { -1, ""}
 };
 
 static char*
@@ -320,32 +340,32 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
 
   fprintf(f, "%s", op2name(opcode));
   switch (opcode) {
-  case OP_EXACT1:
+  case OP_STR_1:
     p_string(f, 1, p->exact.s); break;
-  case OP_EXACT2:
+  case OP_STR_2:
     p_string(f, 2, p->exact.s); break;
-  case OP_EXACT3:
+  case OP_STR_3:
     p_string(f, 3, p->exact.s); break;
-  case OP_EXACT4:
+  case OP_STR_4:
     p_string(f, 4, p->exact.s); break;
-  case OP_EXACT5:
+  case OP_STR_5:
     p_string(f, 5, p->exact.s); break;
-  case OP_EXACTN:
+  case OP_STR_N:
     len = p->exact_n.n;
     p_string(f, len, p->exact_n.s); break;
-  case OP_EXACTMB2N1:
+  case OP_STR_MB2N1:
     p_string(f, 2, p->exact.s); break;
-  case OP_EXACTMB2N2:
+  case OP_STR_MB2N2:
     p_string(f, 4, p->exact.s); break;
-  case OP_EXACTMB2N3:
+  case OP_STR_MB2N3:
     p_string(f, 3, p->exact.s); break;
-  case OP_EXACTMB2N:
+  case OP_STR_MB2N:
     len = p->exact_n.n;
     p_len_string(f, len, 2, p->exact_n.s); break;
-  case OP_EXACTMB3N:
+  case OP_STR_MB3N:
     len = p->exact_n.n;
     p_len_string(f, len, 3, p->exact_n.s); break;
-  case OP_EXACTMBN:
+  case OP_STR_MBN:
     {
       int mb_len;
 
@@ -357,11 +377,11 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
       while (n-- > 0) { fputc(*q++, f); }
     }
     break;
-  case OP_EXACT1_IC:
+  case OP_STR_1_IC:
     len = enclen(enc, p->exact.s);
     p_string(f, len, p->exact.s);
     break;
-  case OP_EXACTN_IC:
+  case OP_STR_N_IC:
     len = p->exact_n.n;
     p_len_string(f, len, 1, p->exact_n.s);
     break;
@@ -375,13 +395,13 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
   case OP_CCLASS_MB_NOT:
     {
       OnigCodePoint ncode;
-      OnigCodePoint* codes;      
+      OnigCodePoint* codes;
 
       codes = (OnigCodePoint* )p->cclass_mb.mb;
       GET_CODE_POINT(ncode, codes);
       codes++;
       GET_CODE_POINT(code, codes);
-      fprintf(f, ":%u:%u", code, ncode);
+      fprintf(f, ":%d:0x%x", ncode, code);
     }
     break;
   case OP_CCLASS_MIX:
@@ -447,15 +467,18 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
     }
     break;
 
-  case OP_MEMORY_START:
-  case OP_MEMORY_START_PUSH:
+  case OP_MEM_START:
+  case OP_MEM_START_PUSH:
     mem = p->memory_start.num;
     fprintf(f, ":%d", mem);
     break;
-  case OP_MEMORY_END_PUSH:
-  case OP_MEMORY_END_PUSH_REC:
-  case OP_MEMORY_END:
-  case OP_MEMORY_END_REC:
+
+  case OP_MEM_END:
+  case OP_MEM_END_PUSH:
+#ifdef USE_CALL
+  case OP_MEM_END_REC:
+  case OP_MEM_END_PUSH_REC:
+#endif
     mem = p->memory_end.num;
     fprintf(f, ":%d", mem);
     break;
@@ -499,8 +522,6 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
 
   case OP_REPEAT_INC:
   case OP_REPEAT_INC_NG:
-  case OP_REPEAT_INC_SG:
-  case OP_REPEAT_INC_NG_SG:
     mem = p->repeat.id;
     fprintf(f, ":%d", mem);
     break;
@@ -511,7 +532,9 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
     break;
   case OP_EMPTY_CHECK_END:
   case OP_EMPTY_CHECK_END_MEMST:
+#ifdef USE_CALL
   case OP_EMPTY_CHECK_END_MEMST_PUSH:
+#endif
     mem = p->empty_check_end.mem;
     fprintf(f, ":%d", mem);
     break;
@@ -534,10 +557,12 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
     p_rel_addr(f, addr, p, start);
     break;
 
+#ifdef USE_CALL
   case OP_CALL:
     addr = p->call.addr;
     fprintf(f, ":{/%d}", addr);
     break;
+#endif
 
   case OP_PUSH_SAVE_VAL:
     {
@@ -607,7 +632,9 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
   case OP_ATOMIC_START:
   case OP_ATOMIC_END:
   case OP_LOOK_BEHIND_NOT_END:
+#ifdef USE_CALL
   case OP_RETURN:
+#endif
     break;
 
   default:
@@ -615,7 +642,7 @@ print_compiled_byte_code(FILE* f, regex_t* reg, int index,
     break;
   }
 }
-#endif /* ONIG_DEBUG */
+#endif /* defined(ONIG_DEBUG_COMPILE) || defined(ONIG_DEBUG_MATCH) */
 
 #ifdef ONIG_DEBUG_COMPILE
 extern void
@@ -625,8 +652,8 @@ onig_print_compiled_byte_code_list(FILE* f, regex_t* reg)
   Operation* start = reg->ops;
   Operation* end   = reg->ops + reg->ops_used;
 
-  fprintf(f, "bt_mem_start: 0x%x, bt_mem_end: 0x%x\n",
-          reg->bt_mem_start, reg->bt_mem_end);
+  fprintf(f, "push_mem_start: 0x%x, push_mem_end: 0x%x\n",
+          reg->push_mem_start, reg->push_mem_end);
   fprintf(f, "code-length: %d\n", reg->ops_used);
 
   bp = start;
@@ -943,7 +970,7 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
       result = ONIGERR_INVALID_ARGUMENT;\
     }\
     best_len = result;\
-    goto finish;\
+    goto match_at_end;\
     break;\
   }\
 } while(0)
@@ -965,18 +992,26 @@ onig_region_copy(OnigRegion* to, OnigRegion* from)
 /* handled by normal-POP */
 #define STK_MEM_START              0x0010
 #define STK_MEM_END                0x8030
-#define STK_REPEAT_INC             0x0050
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+#define STK_REPEAT_INC             (0x0040 | STK_MASK_POP_HANDLED)
+#else
+#define STK_REPEAT_INC             0x0040
+#endif
 #ifdef USE_CALLOUT
 #define STK_CALLOUT                0x0070
 #endif
 
 /* avoided by normal-POP */
 #define STK_VOID                   0x0000  /* for fill a blank */
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+#define STK_EMPTY_CHECK_START      (0x3000 | STK_MASK_POP_HANDLED)
+#else
 #define STK_EMPTY_CHECK_START      0x3000
+#endif
 #define STK_EMPTY_CHECK_END        0x5000  /* for recursive call */
 #define STK_MEM_END_MARK           0x8100
 #define STK_TO_VOID_START          0x1200  /* mark for "(?>...)" */
-#define STK_REPEAT                 0x0300
+/* #define STK_REPEAT                 0x0300 */
 #define STK_CALL_FRAME             0x0400
 #define STK_RETURN                 0x0500
 #define STK_SAVE_VAL               0x0600
@@ -1002,11 +1037,10 @@ typedef struct _StackType {
       UChar*     pstr_prev; /* previous char position of pstr */
     } state;
     struct {
-      int        count;  /* for OP_REPEAT_INC, OP_REPEAT_INC_NG */
-      Operation* pcode;  /* byte code position (head of repeated target) */
-    } repeat;
-    struct {
-      StackIndex si;     /* index of stack */
+      int        count;
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+      StackIndex prev_index;  /* index of stack */
+#endif
     } repeat_inc;
     struct {
       UChar *pstr;       /* start/end position */
@@ -1015,7 +1049,10 @@ typedef struct _StackType {
       StackIndex prev_end;    /* prev. info (for backtrack  "(...)*" ) */
     } mem;
     struct {
-      UChar *pstr;       /* start position */
+      UChar *pstr;            /* start position */
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+      StackIndex prev_index;  /* index of stack */
+#endif
     } empty_check;
 #ifdef USE_CALL
     struct {
@@ -1061,29 +1098,64 @@ struct OnigCalloutArgsStruct {
 
 #endif
 
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+
+#define PTR_NUM_SIZE(reg)  ((reg)->num_repeat + (reg)->num_empty_check + ((reg)->num_mem + 1) * 2)
+#define UPDATE_FOR_STACK_REALLOC do{\
+  repeat_stk      = (StackIndex* )alloc_base;\
+  empty_check_stk = (StackIndex* )(repeat_stk + reg->num_repeat);\
+  mem_start_stk   = (StackIndex* )(empty_check_stk + reg->num_empty_check);\
+  mem_end_stk     = mem_start_stk + num_mem + 1;\
+} while(0)
+
+#define SAVE_REPEAT_STK_VAR(sid) stk->u.repeat_inc.prev_index = repeat_stk[sid]
+#define LOAD_TO_REPEAT_STK_VAR(sid)  repeat_stk[sid] = GET_STACK_INDEX(stk)
+#define POP_REPEAT_INC  else if (stk->type == STK_REPEAT_INC) {repeat_stk[stk->zid] = stk->u.repeat_inc.prev_index;}
+
+#define SAVE_EMPTY_CHECK_STK_VAR(sid) stk->u.empty_check.prev_index = empty_check_stk[sid]
+#define LOAD_TO_EMPTY_CHECK_STK_VAR(sid)  empty_check_stk[sid] = GET_STACK_INDEX(stk)
+#define POP_EMPTY_CHECK_START  else if (stk->type == STK_EMPTY_CHECK_START) {empty_check_stk[stk->zid] = stk->u.empty_check.prev_index;}
+
+#else
+
+#define PTR_NUM_SIZE(reg)  (((reg)->num_mem + 1) * 2)
+#define UPDATE_FOR_STACK_REALLOC do{\
+  mem_start_stk = (StackIndex* )alloc_base;\
+  mem_end_stk   = mem_start_stk + num_mem + 1;\
+} while(0)
+
+#define SAVE_REPEAT_STK_VAR(sid)
+#define LOAD_TO_REPEAT_STK_VAR(sid)
+#define POP_REPEAT_INC
+
+#define SAVE_EMPTY_CHECK_STK_VAR(sid)
+#define LOAD_TO_EMPTY_CHECK_STK_VAR(sid)
+#define POP_EMPTY_CHECK_START
+
+#endif /* USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR */
 
 #ifdef USE_FIND_LONGEST_SEARCH_ALL_OF_RANGE
-#define MATCH_ARG_INIT(msa, reg, arg_option, arg_region, arg_start, mp) do { \
+#define MATCH_ARG_INIT(msa, reg, arg_option, arg_region, arg_start, mpv) do { \
   (msa).stack_p  = (void* )0;\
   (msa).options  = (arg_option);\
   (msa).region   = (arg_region);\
   (msa).start    = (arg_start);\
-  (msa).match_stack_limit  = (mp)->match_stack_limit;\
-  (msa).retry_limit_in_match = (mp)->retry_limit_in_match;\
-  (msa).mp = mp;\
+  (msa).match_stack_limit  = (mpv)->match_stack_limit;\
+  (msa).retry_limit_in_match = (mpv)->retry_limit_in_match;\
+  (msa).mp = mpv;\
   (msa).best_len = ONIG_MISMATCH;\
-  (msa).ptr_num  = (reg)->num_repeat + ((reg)->num_mem + 1) * 2; \
+  (msa).ptr_num  = PTR_NUM_SIZE(reg);\
 } while(0)
 #else
-#define MATCH_ARG_INIT(msa, reg, arg_option, arg_region, arg_start, mp) do { \
+#define MATCH_ARG_INIT(msa, reg, arg_option, arg_region, arg_start, mpv) do { \
   (msa).stack_p  = (void* )0;\
   (msa).options  = (arg_option);\
   (msa).region   = (arg_region);\
   (msa).start    = (arg_start);\
-  (msa).match_stack_limit  = (mp)->match_stack_limit;\
-  (msa).retry_limit_in_match = (mp)->retry_limit_in_match;\
-  (msa).mp = mp;\
-  (msa).ptr_num  = (reg)->num_repeat + ((reg)->num_mem + 1) * 2; \
+  (msa).match_stack_limit  = (mpv)->match_stack_limit;\
+  (msa).retry_limit_in_match = (mpv)->retry_limit_in_match;\
+  (msa).mp = mpv;\
+  (msa).ptr_num  = PTR_NUM_SIZE(reg);\
 } while(0)
 #endif
 
@@ -1138,12 +1210,6 @@ struct OnigCalloutArgsStruct {
   };\
 } while(0)
 
-#define UPDATE_FOR_STACK_REALLOC do{\
-  repeat_stk    = (StackIndex* )alloc_base;\
-  mem_start_stk = (StackIndex* )(repeat_stk + reg->num_repeat);\
-  mem_end_stk   = mem_start_stk + num_mem + 1;\
-} while(0)
-
 static unsigned int MatchStackLimit = DEFAULT_MATCH_STACK_LIMIT_SIZE;
 
 extern unsigned int
@@ -1164,7 +1230,9 @@ onig_set_match_stack_limit_size(unsigned int size)
 static unsigned long RetryLimitInMatch = DEFAULT_RETRY_LIMIT_IN_MATCH;
 
 #define CHECK_RETRY_LIMIT_IN_MATCH  do {\
-  if (retry_in_match_counter++ > retry_limit_in_match) goto retry_limit_in_match_over;\
+  if (retry_in_match_counter++ > retry_limit_in_match) {\
+    MATCH_AT_ERROR_RETURN(ONIGERR_RETRY_LIMIT_IN_MATCH_OVER);\
+  }\
 } while (0)
 
 #else
@@ -1554,19 +1622,23 @@ stack_double(int is_alloca, char** arg_alloc_base,
 #define STACK_PUSH_ALT_LOOK_BEHIND_NOT(pat,s,sprev) \
   STACK_PUSH(STK_ALT_LOOK_BEHIND_NOT,pat,s,sprev)
 
+#if 0
 #define STACK_PUSH_REPEAT(sid, pat) do {\
   STACK_ENSURE(1);\
   stk->type = STK_REPEAT;\
   stk->zid  = (sid);\
-  stk->u.repeat.pcode  = (pat);\
-  stk->u.repeat.count  = 0;\
+  stk->u.repeat.pcode = (pat);\
   STACK_INC;\
 } while(0)
+#endif
 
-#define STACK_PUSH_REPEAT_INC(sindex) do {\
+#define STACK_PUSH_REPEAT_INC(sid, ct) do {\
   STACK_ENSURE(1);\
   stk->type = STK_REPEAT_INC;\
-  stk->u.repeat_inc.si  = (sindex);\
+  stk->zid  = (sid);\
+  stk->u.repeat_inc.count = (ct);\
+  SAVE_REPEAT_STK_VAR(sid);\
+  LOAD_TO_REPEAT_STK_VAR(sid);\
   STACK_INC;\
 } while(0)
 
@@ -1639,6 +1711,8 @@ stack_double(int is_alloca, char** arg_alloc_base,
   stk->type = STK_EMPTY_CHECK_START;\
   stk->zid  = (cnum);\
   stk->u.empty_check.pstr = (s);\
+  SAVE_EMPTY_CHECK_STK_VAR(cnum);\
+  LOAD_TO_EMPTY_CHECK_STK_VAR(cnum);\
   STACK_INC;\
 } while(0)
 
@@ -1776,7 +1850,7 @@ stack_double(int is_alloca, char** arg_alloc_base,
 #define STACK_BASE_CHECK(p, at) \
   if ((p) < stk_base) {\
     fprintf(stderr, "at %s\n", at);\
-    goto stack_error;\
+    MATCH_AT_ERROR_RETURN(ONIGERR_STACK_BUG);\
   }
 #else
 #define STACK_BASE_CHECK(p, at)
@@ -1827,13 +1901,12 @@ stack_double(int is_alloca, char** arg_alloc_base,
           mem_start_stk[stk->zid] = stk->u.mem.prev_start;\
           mem_end_stk[stk->zid]   = stk->u.mem.prev_end;\
         }\
-        else if (stk->type == STK_REPEAT_INC) {\
-          STACK_AT(stk->u.repeat_inc.si)->u.repeat.count--;\
-        }\
         else if (stk->type == STK_MEM_END) {\
           mem_start_stk[stk->zid] = stk->u.mem.prev_start;\
           mem_end_stk[stk->zid]   = stk->u.mem.prev_end;\
         }\
+        POP_REPEAT_INC \
+        POP_EMPTY_CHECK_START \
         POP_CALLOUT_CASE\
       }\
     }\
@@ -1852,13 +1925,12 @@ stack_double(int is_alloca, char** arg_alloc_base,
           mem_start_stk[stk->zid] = stk->u.mem.prev_start;\
           mem_end_stk[stk->zid]   = stk->u.mem.prev_end;\
         }\
-        else if (stk->type == STK_REPEAT_INC) {\
-          STACK_AT(stk->u.repeat_inc.si)->u.repeat.count--;\
-        }\
         else if (stk->type == STK_MEM_END) {\
           mem_start_stk[stk->zid] = stk->u.mem.prev_start;\
           mem_end_stk[stk->zid]   = stk->u.mem.prev_end;\
         }\
+        POP_REPEAT_INC \
+        POP_EMPTY_CHECK_START \
         /* Don't call callout here because negation of total success by (?!..) (?<!..) */\
       }\
     }\
@@ -1910,26 +1982,47 @@ stack_double(int is_alloca, char** arg_alloc_base,
   }\
 } while(0)
 
-#define STACK_EMPTY_CHECK(isnull,sid,s) do {\
-  StackType* k = stk;\
+
+#define EMPTY_CHECK_START_SEARCH(sid, k) do {\
+  k = stk;\
   while (1) {\
     k--;\
-    STACK_BASE_CHECK(k, "STACK_EMPTY_CHECK"); \
+    STACK_BASE_CHECK(k, "EMPTY_CHECK_START_SEARCH"); \
     if (k->type == STK_EMPTY_CHECK_START) {\
-      if (k->zid == (sid)) {\
-        (isnull) = (k->u.empty_check.pstr == (s));\
-        break;\
-      }\
+      if (k->zid == (sid)) break;\
     }\
   }\
 } while(0)
 
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+
+#define GET_EMPTY_CHECK_START(sid, k) do {\
+  if (reg->num_call == 0) {\
+    k = STACK_AT(empty_check_stk[sid]);\
+  }\
+  else {\
+    EMPTY_CHECK_START_SEARCH(sid, k);\
+  }\
+} while(0)
+#else
+
+#define GET_EMPTY_CHECK_START(sid, k)  EMPTY_CHECK_START_SEARCH(sid, k)
+
+#endif
+
+
+#define STACK_EMPTY_CHECK(isnull, sid, s) do {\
+  StackType* k;\
+  GET_EMPTY_CHECK_START(sid, k);\
+  (isnull) = (k->u.empty_check.pstr == (s));\
+} while(0)
+
 #define STACK_MEM_START_GET_PREV_END_ADDR(k /* STK_MEM_START*/, reg, addr) do {\
   if (k->u.mem.prev_end == INVALID_STACK_INDEX) {\
     (addr) = 0;\
   }\
   else {\
-    if (MEM_STATUS_AT((reg)->bt_mem_end, k->zid))\
+    if (MEM_STATUS_AT((reg)->push_mem_end, k->zid))\
       (addr) = STACK_AT(k->u.mem.prev_end)->u.mem.pstr;\
     else\
       (addr) = (UChar* )k->u.mem.prev_end;\
@@ -1937,45 +2030,30 @@ stack_double(int is_alloca, char** arg_alloc_base,
 } while (0)
 
 #ifdef USE_STUBBORN_CHECK_CAPTURES_IN_EMPTY_REPEAT
-#define STACK_EMPTY_CHECK_MEM(isnull,sid,s,reg) do {\
-  StackType* k = stk;\
-  while (1) {\
-    k--;\
-    STACK_BASE_CHECK(k, "STACK_EMPTY_CHECK_MEM"); \
-    if (k->type == STK_EMPTY_CHECK_START) {\
-      if (k->zid == (sid)) {\
-        if (k->u.empty_check.pstr != (s)) {\
-          (isnull) = 0;\
-          break;\
+#define STACK_EMPTY_CHECK_MEM(isnull, sid, s, reg) do {\
+  StackType* k;\
+  GET_EMPTY_CHECK_START(sid, k);\
+  if (k->u.empty_check.pstr != (s)) {\
+    (isnull) = 0;\
+  }\
+  else {\
+    UChar* endp;\
+    (isnull) = 1;\
+    while (k < stk) {\
+      if (k->type == STK_MEM_START &&\
+        MEM_STATUS_LIMIT_AT((reg)->empty_status_mem, k->zid)) {\
+        STACK_MEM_START_GET_PREV_END_ADDR(k, reg, endp);\
+        if (endp == 0) {\
+          (isnull) = 0; break;\
         }\
-        else {\
-          UChar* endp;\
-          int level = 0;\
-          (isnull) = 1;\
-          while (k < stk) {\
-            if (k->type == STK_MEM_START && level == 0) {\
-              STACK_MEM_START_GET_PREV_END_ADDR(k, reg, endp);\
-              if (endp == 0) {\
-                (isnull) = 0; break;\
-              }\
-              else if (STACK_AT(k->u.mem.prev_start)->u.mem.pstr != endp) {\
-                (isnull) = 0; break;\
-              }\
-              else if (endp != s) {\
-                (isnull) = -1; /* empty, but position changed */ \
-              }\
-            }\
-            else if (k->type == STK_PREC_READ_START) {\
-              level++;\
-            }\
-            else if (k->type == STK_PREC_READ_END) {\
-              level--;\
-            }\
-            k++;\
-          }\
-          break;\
+        else if (STACK_AT(k->u.mem.prev_start)->u.mem.pstr != endp) {\
+          (isnull) = 0; break;\
+        }\
+        else if (endp != s) {\
+          (isnull) = -1; /* empty, but position changed */ \
         }\
       }\
+      k++;\
     }\
   }\
 } while(0)
@@ -1995,11 +2073,11 @@ stack_double(int is_alloca, char** arg_alloc_base,
           }\
           else {\
             UChar* endp;\
-            int prec_level = 0;\
             (isnull) = 1;\
             while (k < stk) {\
               if (k->type == STK_MEM_START) {\
-                if (level == 0 && prec_level == 0) {\
+                if (level == 0 && \
+                  MEM_STATUS_LIMIT_AT((reg)->empty_status_mem, k->zid) !=0) {\
                   STACK_MEM_START_GET_PREV_END_ADDR(k, reg, endp);\
                   if (endp == 0) {\
                     (isnull) = 0; break;\
@@ -2018,12 +2096,6 @@ stack_double(int is_alloca, char** arg_alloc_base,
               else if (k->type == STK_EMPTY_CHECK_END) {\
                 if (k->zid == (sid)) level--;\
               }\
-              else if (k->type == STK_PREC_READ_START) {\
-                prec_level++;\
-              }\
-              else if (k->type == STK_PREC_READ_END) {\
-                prec_level--;\
-              }\
               k++;\
             }\
             break;\
@@ -2062,24 +2134,45 @@ stack_double(int is_alloca, char** arg_alloc_base,
 } while(0)
 #endif /* USE_STUBBORN_CHECK_CAPTURES_IN_EMPTY_REPEAT */
 
-#define STACK_GET_REPEAT(sid, k) do {\
-  int level = 0;\
-  k = stk;\
+#define STACK_GET_REPEAT_COUNT_SEARCH(sid, c) do {\
+  StackType* k = stk;\
   while (1) {\
-    k--;\
-    STACK_BASE_CHECK(k, "STACK_GET_REPEAT"); \
-    if (k->type == STK_REPEAT) {\
-      if (level == 0) {\
-        if (k->zid == (sid)) {\
-          break;\
+    (k)--;\
+    STACK_BASE_CHECK(k, "STACK_GET_REPEAT_COUNT_SEARCH");\
+    if ((k)->type == STK_REPEAT_INC) {\
+      if ((k)->zid == (sid)) {\
+        (c) = (k)->u.repeat_inc.count;\
+        break;\
+      }\
+    }\
+    else if ((k)->type == STK_RETURN) {\
+      int level = -1;\
+      while (1) {\
+        (k)--;\
+        if ((k)->type == STK_CALL_FRAME) {\
+          level++;\
+          if (level == 0) break;\
         }\
+        else if ((k)->type == STK_RETURN) level--;\
       }\
     }\
-    else if (k->type == STK_CALL_FRAME) level--;\
-    else if (k->type == STK_RETURN)     level++;\
   }\
 } while(0)
 
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+
+#define STACK_GET_REPEAT_COUNT(sid, c) do {\
+  if (reg->num_call == 0) {\
+    (c) = (STACK_AT(repeat_stk[sid]))->u.repeat_inc.count;\
+  }\
+  else {\
+    STACK_GET_REPEAT_COUNT_SEARCH(sid, c);\
+  }\
+} while(0)
+#else
+#define STACK_GET_REPEAT_COUNT(sid, c) STACK_GET_REPEAT_COUNT_SEARCH(sid, c)
+#endif
+
 #define STACK_RETURN(addr)  do {\
   int level = 0;\
   StackType* k = stk;\
@@ -2481,6 +2574,8 @@ typedef struct {
 #define MATCH_DEBUG_OUT(offset)
 #endif
 
+#define MATCH_AT_ERROR_RETURN(err_code)  best_len = err_code; goto match_at_end
+
 
 /* match data(str - end) from position (sstart). */
 /* if sstart == str then set sprev to NULL. */
@@ -2500,20 +2595,20 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   static const void *opcode_to_label[] = {
   &&L_FINISH,
   &&L_END,
-  &&L_EXACT1,
-  &&L_EXACT2,
-  &&L_EXACT3,
-  &&L_EXACT4,
-  &&L_EXACT5,
-  &&L_EXACTN,
-  &&L_EXACTMB2N1,
-  &&L_EXACTMB2N2,
-  &&L_EXACTMB2N3,
-  &&L_EXACTMB2N,
-  &&L_EXACTMB3N,
-  &&L_EXACTMBN,
-  &&L_EXACT1_IC,
-  &&L_EXACTN_IC,
+  &&L_STR_1,
+  &&L_STR_2,
+  &&L_STR_3,
+  &&L_STR_4,
+  &&L_STR_5,
+  &&L_STR_N,
+  &&L_STR_MB2N1,
+  &&L_STR_MB2N2,
+  &&L_STR_MB2N3,
+  &&L_STR_MB2N,
+  &&L_STR_MB3N,
+  &&L_STR_MBN,
+  &&L_STR_1_IC,
+  &&L_STR_N_IC,
   &&L_CCLASS,
   &&L_CCLASS_MB,
   &&L_CCLASS_MIX,
@@ -2551,12 +2646,16 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   &&L_BACKREF_WITH_LEVEL_IC,
   &&L_BACKREF_CHECK,
   &&L_BACKREF_CHECK_WITH_LEVEL,
-  &&L_MEMORY_START,
-  &&L_MEMORY_START_PUSH,
-  &&L_MEMORY_END_PUSH,
-  &&L_MEMORY_END_PUSH_REC,
-  &&L_MEMORY_END,
-  &&L_MEMORY_END_REC,
+  &&L_MEM_START,
+  &&L_MEM_START_PUSH,
+  &&L_MEM_END_PUSH,
+#ifdef USE_CALL
+  &&L_MEM_END_PUSH_REC,
+#endif
+  &&L_MEM_END,
+#ifdef USE_CALL
+  &&L_MEM_END_REC,
+#endif
   &&L_FAIL,
   &&L_JUMP,
   &&L_PUSH,
@@ -2570,12 +2669,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   &&L_REPEAT_NG,
   &&L_REPEAT_INC,
   &&L_REPEAT_INC_NG,
-  &&L_REPEAT_INC_SG,
-  &&L_REPEAT_INC_NG_SG,
   &&L_EMPTY_CHECK_START,
   &&L_EMPTY_CHECK_END,
   &&L_EMPTY_CHECK_END_MEMST,
+#ifdef USE_CALL
   &&L_EMPTY_CHECK_END_MEMST_PUSH,
+#endif
   &&L_PREC_READ_START,
   &&L_PREC_READ_END,
   &&L_PREC_READ_NOT_START,
@@ -2585,10 +2684,12 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   &&L_LOOK_BEHIND,
   &&L_LOOK_BEHIND_NOT_START,
   &&L_LOOK_BEHIND_NOT_END,
-  &&L_CALL,
-  &&L_RETURN,
   &&L_PUSH_SAVE_VAL,
   &&L_UPDATE_VAR,
+#ifdef USE_CALL
+  &&L_CALL,
+  &&L_RETURN,
+#endif
 #ifdef USE_CALLOUT
   &&L_CALLOUT_CONTENTS,
   &&L_CALLOUT_NAME,
@@ -2606,15 +2707,17 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
   char *alloc_base;
   StackType *stk_base, *stk, *stk_end;
   StackType *stkp; /* used as any purpose. */
-  StackIndex si;
-  StackIndex *repeat_stk;
   StackIndex *mem_start_stk, *mem_end_stk;
   UChar* keep;
+
+#ifdef USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR
+  StackIndex *repeat_stk;
+  StackIndex *empty_check_stk;
+#endif
 #ifdef USE_RETRY_LIMIT_IN_MATCH
   unsigned long retry_limit_in_match;
   unsigned long retry_in_match_counter;
 #endif
-
 #ifdef USE_CALLOUT
   int of;
 #endif
@@ -2700,15 +2803,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
             rmt[0].rm_eo = (regoff_t )(s    - str);
             for (i = 1; i <= num_mem; i++) {
               if (mem_end_stk[i] != INVALID_STACK_INDEX) {
-                if (MEM_STATUS_AT(reg->bt_mem_start, i))
-                  rmt[i].rm_so = (regoff_t )(STACK_AT(mem_start_stk[i])->u.mem.pstr - str);
-                else
-                  rmt[i].rm_so = (regoff_t )((UChar* )((void* )(mem_start_stk[i])) - str);
-
-                rmt[i].rm_eo = (regoff_t )((MEM_STATUS_AT(reg->bt_mem_end, i)
-                                            ? STACK_AT(mem_end_stk[i])->u.mem.pstr
-                                            : (UChar* )((void* )mem_end_stk[i]))
-                                           - str);
+                rmt[i].rm_so = (regoff_t )(STACK_MEM_START(reg, i) - str);
+                rmt[i].rm_eo = (regoff_t )(STACK_MEM_END(reg, i)   - str);
               }
               else {
                 rmt[i].rm_so = rmt[i].rm_eo = ONIG_REGION_NOTPOS;
@@ -2721,14 +2817,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
             region->end[0] = (int )(s    - str);
             for (i = 1; i <= num_mem; i++) {
               if (mem_end_stk[i] != INVALID_STACK_INDEX) {
-                if (MEM_STATUS_AT(reg->bt_mem_start, i))
-                  region->beg[i] = (int )(STACK_AT(mem_start_stk[i])->u.mem.pstr - str);
-                else
-                  region->beg[i] = (int )((UChar* )((void* )mem_start_stk[i]) - str);
-
-                region->end[i] = (int )((MEM_STATUS_AT(reg->bt_mem_end, i)
-                                         ? STACK_AT(mem_end_stk[i])->u.mem.pstr
-                                         : (UChar* )((void* )mem_end_stk[i])) - str);
+                region->beg[i] = (int )(STACK_MEM_START(reg, i) - str);
+                region->end[i] = (int )(STACK_MEM_END(reg, i)   - str);
               }
               else {
                 region->beg[i] = region->end[i] = ONIG_REGION_NOTPOS;
@@ -2756,10 +2846,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
               stkp = stk_base;
               r = make_capture_history_tree(region->history_root, &stkp,
                                             stk, (UChar* )str, reg);
-              if (r < 0) {
-                best_len = r; /* error code */
-                goto finish;
-              }
+              if (r < 0) MATCH_AT_ERROR_RETURN(r);
             }
 #endif /* USE_CAPTURE_HISTORY */
 #ifdef USE_POSIX_API_REGION_OPTION
@@ -2784,9 +2871,9 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       }
 
       /* default behavior: return first-matching result. */
-      goto finish;
+      goto match_at_end;
 
-    CASE_OP(EXACT1)
+    CASE_OP(STR_1)
       DATA_ENSURE(1);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2794,7 +2881,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       NEXT_OUT;
 
-    CASE_OP(EXACT1_IC)
+    CASE_OP(STR_1_IC)
       {
         int len;
         UChar *q, lowbuf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
@@ -2815,7 +2902,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       NEXT_OUT;
 
-    CASE_OP(EXACT2)
+    CASE_OP(STR_2)
       DATA_ENSURE(2);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2826,7 +2913,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACT3)
+    CASE_OP(STR_3)
       DATA_ENSURE(3);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2839,7 +2926,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACT4)
+    CASE_OP(STR_4)
       DATA_ENSURE(4);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2854,7 +2941,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACT5)
+    CASE_OP(STR_5)
       DATA_ENSURE(5);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2871,7 +2958,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTN)
+    CASE_OP(STR_N)
       tlen = p->exact_n.n;
       DATA_ENSURE(tlen);
       ps = p->exact_n.s;
@@ -2882,7 +2969,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTN_IC)
+    CASE_OP(STR_N_IC)
       {
         int len;
         UChar *q, *endp, lowbuf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
@@ -2900,6 +2987,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           DATA_ENSURE(0);
           q = lowbuf;
           while (len-- > 0) {
+            if (ps >= endp) goto fail;
             if (*ps != *q) goto fail;
             ps++; q++;
           }
@@ -2909,7 +2997,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTMB2N1)
+    CASE_OP(STR_MB2N1)
       DATA_ENSURE(2);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2919,7 +3007,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       NEXT_OUT;
 
-    CASE_OP(EXACTMB2N2)
+    CASE_OP(STR_MB2N2)
       DATA_ENSURE(4);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2934,7 +3022,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTMB2N3)
+    CASE_OP(STR_MB2N3)
       DATA_ENSURE(6);
       ps = p->exact.s;
       if (*ps != *s) goto fail;
@@ -2953,7 +3041,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTMB2N)
+    CASE_OP(STR_MB2N)
       tlen = p->exact_n.n;
       DATA_ENSURE(tlen * 2);
       ps = p->exact_n.s;
@@ -2967,7 +3055,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTMB3N)
+    CASE_OP(STR_MB3N)
       tlen = p->exact_n.n;
       DATA_ENSURE(tlen * 3);
       ps = p->exact_n.s;
@@ -2983,7 +3071,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(EXACTMBN)
+    CASE_OP(STR_MBN)
       tlen  = p->exact_len_n.len; /* mb byte len */
       tlen2 = p->exact_len_n.n;   /* number of chars */
       tlen2 *= tlen;
@@ -3014,7 +3102,6 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         UChar *ss;
         int mb_len;
 
-        DATA_ENSURE(1);
         mb_len = enclen(encode, s);
         DATA_ENSURE(mb_len);
         ss = s;
@@ -3303,7 +3390,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           break;
 #endif
         default:
-          goto bytecode_error;
+          MATCH_AT_ERROR_RETURN(ONIGERR_UNDEFINED_BYTECODE);
           break;
         }
 
@@ -3403,46 +3490,50 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(MEMORY_START_PUSH)
+    CASE_OP(MEM_START_PUSH)
       mem = p->memory_start.num;
       STACK_PUSH_MEM_START(mem, s);
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(MEMORY_START)
+    CASE_OP(MEM_START)
       mem = p->memory_start.num;
       mem_start_stk[mem] = (StackIndex )((void* )s);
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(MEMORY_END_PUSH)
+    CASE_OP(MEM_END_PUSH)
       mem = p->memory_end.num;
       STACK_PUSH_MEM_END(mem, s);
       INC_OP;
       JUMP_OUT;
 
-    CASE_OP(MEMORY_END)
+    CASE_OP(MEM_END)
       mem = p->memory_end.num;
       mem_end_stk[mem] = (StackIndex )((void* )s);
       INC_OP;
       JUMP_OUT;
 
 #ifdef USE_CALL
-    CASE_OP(MEMORY_END_PUSH_REC)
-      mem = p->memory_end.num;
-      STACK_GET_MEM_START(mem, stkp); /* should be before push mem-end. */
-      si = GET_STACK_INDEX(stkp);
-      STACK_PUSH_MEM_END(mem, s);
-      mem_start_stk[mem] = si;
-      INC_OP;
-      JUMP_OUT;
+    CASE_OP(MEM_END_PUSH_REC)
+      {
+        StackIndex si;
+
+        mem = p->memory_end.num;
+        STACK_GET_MEM_START(mem, stkp); /* should be before push mem-end. */
+        si = GET_STACK_INDEX(stkp);
+        STACK_PUSH_MEM_END(mem, s);
+        mem_start_stk[mem] = si;
+        INC_OP;
+        JUMP_OUT;
+      }
 
-    CASE_OP(MEMORY_END_REC)
+    CASE_OP(MEM_END_REC)
       mem = p->memory_end.num;
       mem_end_stk[mem] = (StackIndex )((void* )s);
       STACK_GET_MEM_START(mem, stkp);
 
-      if (MEM_STATUS_AT(reg->bt_mem_start, mem))
+      if (MEM_STATUS_AT(reg->push_mem_start, mem))
         mem_start_stk[mem] = GET_STACK_INDEX(stkp);
       else
         mem_start_stk[mem] = (StackIndex )((void* )stkp->u.mem.pstr);
@@ -3470,14 +3561,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         if (mem_end_stk[mem]   == INVALID_STACK_INDEX) goto fail;
         if (mem_start_stk[mem] == INVALID_STACK_INDEX) goto fail;
 
-        if (MEM_STATUS_AT(reg->bt_mem_start, mem))
-          pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
-        else
-          pstart = (UChar* )((void* )mem_start_stk[mem]);
-
-        pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
-                ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
-                : (UChar* )((void* )mem_end_stk[mem]));
+        pstart = STACK_MEM_START(reg, mem);
+        pend   = STACK_MEM_END(reg, mem);
         n = (int )(pend - pstart);
         if (n != 0) {
           DATA_ENSURE(n);
@@ -3499,14 +3584,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         if (mem_end_stk[mem]   == INVALID_STACK_INDEX) goto fail;
         if (mem_start_stk[mem] == INVALID_STACK_INDEX) goto fail;
 
-        if (MEM_STATUS_AT(reg->bt_mem_start, mem))
-          pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
-        else
-          pstart = (UChar* )((void* )mem_start_stk[mem]);
-
-        pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
-                ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
-                : (UChar* )((void* )mem_end_stk[mem]));
+        pstart = STACK_MEM_START(reg, mem);
+        pend   = STACK_MEM_END(reg, mem);
         n = (int )(pend - pstart);
         if (n != 0) {
           DATA_ENSURE(n);
@@ -3531,14 +3610,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           if (mem_end_stk[mem]   == INVALID_STACK_INDEX) continue;
           if (mem_start_stk[mem] == INVALID_STACK_INDEX) continue;
 
-          if (MEM_STATUS_AT(reg->bt_mem_start, mem))
-            pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
-          else
-            pstart = (UChar* )((void* )mem_start_stk[mem]);
-
-          pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
-                  ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
-                  : (UChar* )((void* )mem_end_stk[mem]));
+          pstart = STACK_MEM_START(reg, mem);
+          pend   = STACK_MEM_END(reg, mem);
           n = (int )(pend - pstart);
           if (n != 0) {
             DATA_ENSURE(n);
@@ -3569,14 +3642,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           if (mem_end_stk[mem]   == INVALID_STACK_INDEX) continue;
           if (mem_start_stk[mem] == INVALID_STACK_INDEX) continue;
 
-          if (MEM_STATUS_AT(reg->bt_mem_start, mem))
-            pstart = STACK_AT(mem_start_stk[mem])->u.mem.pstr;
-          else
-            pstart = (UChar* )((void* )mem_start_stk[mem]);
-
-          pend = (MEM_STATUS_AT(reg->bt_mem_end, mem)
-                  ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
-                  : (UChar* )((void* )mem_end_stk[mem]));
+          pstart = STACK_MEM_START(reg, mem);
+          pend   = STACK_MEM_END(reg, mem);
           n = (int )(pend - pstart);
           if (n != 0) {
             DATA_ENSURE(n);
@@ -3689,12 +3756,10 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
           case OP_PUSH:
           case OP_REPEAT_INC:
           case OP_REPEAT_INC_NG:
-          case OP_REPEAT_INC_SG:
-          case OP_REPEAT_INC_NG_SG:
             INC_OP;
             break;
           default:
-            goto unexpected_bytecode_error;
+            MATCH_AT_ERROR_RETURN(ONIGERR_UNEXPECTED_BYTECODE);
             break;
           }
 #else
@@ -3797,7 +3862,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 
         addr = p->push_if_peek_next.addr;
         c    = p->push_if_peek_next.c;
-        if (c == *s) {
+        if (DATA_ENSURE_CHECK1 && c == *s) {
           STACK_PUSH_ALT(p + addr, s, sprev);
           INC_OP;
           JUMP_OUT;
@@ -3810,10 +3875,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       mem  = p->repeat.id;  /* mem: OP_REPEAT ID */
       addr = p->repeat.addr;
 
-      STACK_ENSURE(1);
-      repeat_stk[mem] = GET_STACK_INDEX(stk);
-      STACK_PUSH_REPEAT(mem, p + 1);
-
+      STACK_PUSH_REPEAT_INC(mem, 0);
       if (reg->repeat_range[mem].lower == 0) {
         STACK_PUSH_ALT(p + addr, s, sprev);
       }
@@ -3824,10 +3886,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       mem  = p->repeat.id;  /* mem: OP_REPEAT ID */
       addr = p->repeat.addr;
 
-      STACK_ENSURE(1);
-      repeat_stk[mem] = GET_STACK_INDEX(stk);
-      STACK_PUSH_REPEAT(mem, p + 1);
-
+      STACK_PUSH_REPEAT_INC(mem, 0);
       if (reg->repeat_range[mem].lower == 0) {
         STACK_PUSH_ALT(p + 1, s, sprev);
         p += addr;
@@ -3838,64 +3897,42 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 
     CASE_OP(REPEAT_INC)
       mem  = p->repeat_inc.id;  /* mem: OP_REPEAT ID */
-      si   = repeat_stk[mem];
-      stkp = STACK_AT(si);
-
-    repeat_inc:
-      stkp->u.repeat.count++;
-      if (stkp->u.repeat.count >= reg->repeat_range[mem].upper) {
+      STACK_GET_REPEAT_COUNT(mem, n);
+      n++;
+      if (n >= reg->repeat_range[mem].upper) {
         /* end of repeat. Nothing to do. */
         INC_OP;
       }
-      else if (stkp->u.repeat.count >= reg->repeat_range[mem].lower) {
+      else if (n >= reg->repeat_range[mem].lower) {
         INC_OP;
         STACK_PUSH_ALT(p, s, sprev);
-        p = STACK_AT(si)->u.repeat.pcode; /* Don't use stkp after PUSH. */
+        p = reg->repeat_range[mem].u.pcode;
       }
       else {
-        p = stkp->u.repeat.pcode;
+        p = reg->repeat_range[mem].u.pcode;
       }
-      STACK_PUSH_REPEAT_INC(si);
+      STACK_PUSH_REPEAT_INC(mem, n);
       CHECK_INTERRUPT_JUMP_OUT;
 
-    CASE_OP(REPEAT_INC_SG)
-      mem = p->repeat_inc.id;  /* mem: OP_REPEAT ID */
-      STACK_GET_REPEAT(mem, stkp);
-      si = GET_STACK_INDEX(stkp);
-      goto repeat_inc;
-
     CASE_OP(REPEAT_INC_NG)
       mem = p->repeat_inc.id;  /* mem: OP_REPEAT ID */
-      si = repeat_stk[mem];
-      stkp = STACK_AT(si);
-
-    repeat_inc_ng:
-      stkp->u.repeat.count++;
-      if (stkp->u.repeat.count < reg->repeat_range[mem].upper) {
-        if (stkp->u.repeat.count >= reg->repeat_range[mem].lower) {
-          Operation* pcode = stkp->u.repeat.pcode;
-
-          STACK_PUSH_REPEAT_INC(si);
-          STACK_PUSH_ALT(pcode, s, sprev);
+      STACK_GET_REPEAT_COUNT(mem, n);
+      n++;
+      STACK_PUSH_REPEAT_INC(mem, n);
+      if (n == reg->repeat_range[mem].upper) {
+        INC_OP;
+      }
+      else {
+        if (n >= reg->repeat_range[mem].lower) {
+          STACK_PUSH_ALT(reg->repeat_range[mem].u.pcode, s, sprev);
           INC_OP;
         }
         else {
-          p = stkp->u.repeat.pcode;
-          STACK_PUSH_REPEAT_INC(si);
+          p = reg->repeat_range[mem].u.pcode;
         }
       }
-      else if (stkp->u.repeat.count == reg->repeat_range[mem].upper) {
-        STACK_PUSH_REPEAT_INC(si);
-        INC_OP;
-      }
       CHECK_INTERRUPT_JUMP_OUT;
 
-    CASE_OP(REPEAT_INC_NG_SG)
-      mem = p->repeat_inc.id;  /* mem: OP_REPEAT ID */
-      STACK_GET_REPEAT(mem, stkp);
-      si = GET_STACK_INDEX(stkp);
-      goto repeat_inc_ng;
-
     CASE_OP(PREC_READ_START)
       STACK_PUSH_PREC_READ_START(s, sprev);
       INC_OP;
@@ -4044,14 +4081,14 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
         OnigCalloutFunc func;
         OnigCalloutArgs args;
 
-        of = ONIG_CALLOUT_OF_NAME;
-        name_id = p->callout_name.id;
-        mem     = p->callout_name.num;
+        of  = ONIG_CALLOUT_OF_NAME;
+        mem = p->callout_name.num;
 
       callout_common_entry:
         e = onig_reg_callout_list_at(reg, mem);
         in = e->in;
         if (of == ONIG_CALLOUT_OF_NAME) {
+          name_id = p->callout_name.id;
           func = onig_get_callout_start_func(reg, mem);
         }
         else {
@@ -4074,7 +4111,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
               call_result = ONIGERR_INVALID_ARGUMENT;
             }
             best_len = call_result;
-            goto finish;
+            goto match_at_end;
             break;
           }
         }
@@ -4100,7 +4137,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 #endif
 
     CASE_OP(FINISH)
-      goto finish;
+      goto match_at_end;
 
 #ifdef ONIG_DEBUG_STATISTICS
     fail:
@@ -4121,37 +4158,472 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
       JUMP_OUT;
 
     DEFAULT_OP
-      goto bytecode_error;
+      MATCH_AT_ERROR_RETURN(ONIGERR_UNDEFINED_BYTECODE);
 
   } BYTECODE_INTERPRETER_END;
 
- finish:
+ match_at_end:
   STACK_SAVE;
   return best_len;
+}
 
-#ifdef ONIG_DEBUG
- stack_error:
-  STACK_SAVE;
-  return ONIGERR_STACK_BUG;
-#endif
+typedef struct {
+  regex_t*    reg;
+  OnigRegion* region;
+} RR;
+
+struct OnigRegSetStruct {
+  RR*          rs;
+  int          n;
+  int          alloc;
+  OnigEncoding enc;
+  int          anchor;      /* BEGIN_BUF, BEGIN_POS, (SEMI_)END_BUF */
+  OnigLen      anc_dmin;    /* (SEMI_)END_BUF anchor distance */
+  OnigLen      anc_dmax;    /* (SEMI_)END_BUF anchor distance */
+  int          all_low_high;
+  int          anychar_inf;
+};
 
- bytecode_error:
-  STACK_SAVE;
-  return ONIGERR_UNDEFINED_BYTECODE;
+enum SearchRangeStatus {
+  SRS_DEAD      = 0,
+  SRS_LOW_HIGH  = 1,
+  SRS_ALL_RANGE = 2
+};
 
-#if defined(ONIG_DEBUG) && !defined(USE_DIRECT_THREADED_CODE)
- unexpected_bytecode_error:
-  STACK_SAVE;
-  return ONIGERR_UNEXPECTED_BYTECODE;
-#endif
+typedef struct {
+  int    state;  /* value of enum SearchRangeStatus */
+  UChar* low;
+  UChar* high;
+  UChar* low_prev;
+  UChar* sch_range;
+} SearchRange;
+
+#define REGSET_MATCH_AND_RETURN_CHECK(upper_range) \
+  r = match_at(reg, str, end, (upper_range), s, prev, msas + i); \
+  if (r != ONIG_MISMATCH) {\
+    if (r >= 0) {\
+      goto match;\
+    }\
+    else goto finish; /* error */ \
+  }
 
-#ifdef USE_RETRY_LIMIT_IN_MATCH
- retry_limit_in_match_over:
-  STACK_SAVE;
-  return ONIGERR_RETRY_LIMIT_IN_MATCH_OVER;
+static inline int
+regset_search_body_position_lead(OnigRegSet* set,
+           const UChar* str, const UChar* end,
+           const UChar* start, const UChar* range, /* match start range */
+           const UChar* orig_range, /* data range */
+           OnigOptionType option, MatchArg* msas, int* rmatch_pos)
+{
+  int r, n, i;
+  UChar *s, *prev;
+  UChar *low, *high, *low_prev;
+  UChar* sch_range;
+  regex_t* reg;
+  OnigEncoding enc;
+  SearchRange* sr;
+
+  n   = set->n;
+  enc = set->enc;
+
+  s = (UChar* )start;
+  if (s > str)
+    prev = onigenc_get_prev_char_head(enc, str, s);
+  else
+    prev = (UChar* )NULL;
+
+  sr = (SearchRange* )xmalloc(sizeof(*sr) * n);
+  CHECK_NULL_RETURN_MEMERR(sr);
+
+  for (i = 0; i < n; i++) {
+    reg = set->rs[i].reg;
+
+    sr[i].state = SRS_DEAD;
+    if (reg->optimize != OPTIMIZE_NONE) {
+      if (reg->dist_max != INFINITE_LEN) {
+        if (end - range > reg->dist_max)
+          sch_range = (UChar* )range + reg->dist_max;
+        else
+          sch_range = (UChar* )end;
+
+        if (forward_search(reg, str, end, s, sch_range, &low, &high, &low_prev)) {
+          sr[i].state = SRS_LOW_HIGH;
+          sr[i].low  = low;
+          sr[i].high = high;
+          sr[i].low_prev = low_prev;
+          sr[i].sch_range = sch_range;
+        }
+      }
+      else {
+        sch_range = (UChar* )end;
+        if (forward_search(reg, str, end, s, sch_range,
+                           &low, &high, (UChar** )NULL)) {
+          goto total_active;
+        }
+      }
+    }
+    else {
+    total_active:
+      sr[i].state    = SRS_ALL_RANGE;
+      sr[i].low      = s;
+      sr[i].high     = (UChar* )range;
+      sr[i].low_prev = prev;
+    }
+  }
+
+#define ACTIVATE_ALL_LOW_HIGH_SEARCH_THRESHOLD_LEN   500
+
+  if (set->all_low_high != 0
+      && range - start > ACTIVATE_ALL_LOW_HIGH_SEARCH_THRESHOLD_LEN) {
+    do {
+      int try_count = 0;
+      for (i = 0; i < n; i++) {
+        if (sr[i].state == SRS_DEAD) continue;
+
+        if (s <  sr[i].low) continue;
+        if (s >= sr[i].high) {
+          if (forward_search(set->rs[i].reg, str, end, s, sr[i].sch_range,
+                             &low, &high, &low_prev) != 0) {
+            sr[i].low      = low;
+            sr[i].high     = high;
+            sr[i].low_prev = low_prev;
+            if (s < low) continue;
+          }
+          else {
+            sr[i].state = SRS_DEAD;
+            continue;
+          }
+        }
+
+        reg = set->rs[i].reg;
+        REGSET_MATCH_AND_RETURN_CHECK(orig_range);
+        try_count++;
+      } /* for (i) */
+
+      if (s >= range) break;
+
+      if (try_count == 0) {
+        low = (UChar* )range;
+        for (i = 0; i < n; i++) {
+          if (sr[i].state == SRS_LOW_HIGH && low > sr[i].low) {
+            low = sr[i].low;
+            low_prev = sr[i].low_prev;
+          }
+        }
+        if (low == range) break;
+
+        s = low;
+        prev = low_prev;
+      }
+      else {
+        prev = s;
+        s += enclen(enc, s);
+      }
+    } while (1);
+  }
+  else {
+    int prev_is_newline = 1;
+    do {
+      for (i = 0; i < n; i++) {
+        if (sr[i].state == SRS_DEAD) continue;
+        if (sr[i].state == SRS_LOW_HIGH) {
+          if (s <  sr[i].low) continue;
+          if (s >= sr[i].high) {
+            if (forward_search(set->rs[i].reg, str, end, s, sr[i].sch_range,
+                               &low, &high, &low_prev) != 0) {
+              sr[i].low      = low;
+              sr[i].high     = high;
+              /* sr[i].low_prev = low_prev; */
+              if (s < low) continue;
+            }
+            else {
+              sr[i].state = SRS_DEAD;
+              continue;
+            }
+          }
+        }
+
+        reg = set->rs[i].reg;
+        if ((reg->anchor & ANCR_ANYCHAR_INF) == 0 || prev_is_newline != 0) {
+          REGSET_MATCH_AND_RETURN_CHECK(orig_range);
+        }
+      }
+
+      if (s >= range) break;
+
+      if (set->anychar_inf != 0)
+        prev_is_newline = ONIGENC_IS_MBC_NEWLINE(set->enc, s, end);
+
+      prev = s;
+      s += enclen(enc, s);
+    } while (1);
+  }
+
+  xfree(sr);
+  return ONIG_MISMATCH;
+
+ finish:
+  xfree(sr);
+  return r;
+
+ match:
+  xfree(sr);
+  *rmatch_pos = (int )(s - str);
+  return i;
+}
+
+static inline int
+regset_search_body_regex_lead(OnigRegSet* set,
+              const UChar* str, const UChar* end,
+              const UChar* start, const UChar* orig_range, OnigRegSetLead lead,
+              OnigOptionType option, OnigMatchParam* mps[], int* rmatch_pos)
+{
+  int r;
+  int i;
+  int n;
+  int match_index;
+  const UChar* ep;
+  regex_t* reg;
+  OnigRegion* region;
+
+  n = set->n;
+
+  match_index = ONIG_MISMATCH;
+  ep = orig_range;
+  for (i = 0; i < n; i++) {
+    reg    = set->rs[i].reg;
+    region = set->rs[i].region;
+    r = search_in_range(reg, str, end, start, ep, orig_range, region, option, mps[i]);
+    if (r > 0) {
+      if (str + r < ep) {
+        match_index = i;
+        *rmatch_pos = r;
+        if (lead == ONIG_REGSET_PRIORITY_TO_REGEX_ORDER)
+          break;
+
+        ep = str + r;
+      }
+    }
+    else if (r == 0) {
+      match_index = i;
+      *rmatch_pos = r;
+      break;
+    }
+  }
+
+  return match_index;
+}
+
+extern int
+onig_regset_search_with_param(OnigRegSet* set,
+           const UChar* str, const UChar* end,
+           const UChar* start, const UChar* range,
+           OnigRegSetLead lead, OnigOptionType option, OnigMatchParam* mps[],
+           int* rmatch_pos)
+{
+  int r;
+  int i;
+  UChar *s, *prev;
+  regex_t* reg;
+  OnigEncoding enc;
+  OnigRegion* region;
+  MatchArg* msas;
+  const UChar *orig_start = start;
+  const UChar *orig_range = range;
+
+  if (set->n == 0)
+    return ONIG_MISMATCH;
+
+  if (IS_POSIX_REGION(option))
+    return ONIGERR_INVALID_ARGUMENT;
+
+  r = 0;
+  enc = set->enc;
+  msas = (MatchArg* )NULL;
+
+  for (i = 0; i < set->n; i++) {
+    reg    = set->rs[i].reg;
+    region = set->rs[i].region;
+    ADJUST_MATCH_PARAM(reg, mps[i]);
+    if (IS_NOT_NULL(region)) {
+      r = onig_region_resize_clear(region, reg->num_mem + 1);
+      if (r != 0) goto finish_no_msa;
+    }
+  }
+
+  if (start > end || start < str) goto mismatch_no_msa;
+  if (str < end) {
+    /* forward search only */
+    if (range <= start)
+      return ONIGERR_INVALID_ARGUMENT;
+  }
+
+  if (ONIG_IS_OPTION_ON(option, ONIG_OPTION_CHECK_VALIDITY_OF_STRING)) {
+    if (! ONIGENC_IS_VALID_MBC_STRING(enc, str, end)) {
+      r = ONIGERR_INVALID_WIDE_CHAR_VALUE;
+      goto finish_no_msa;
+    }
+  }
+
+  if (set->anchor != OPTIMIZE_NONE && str < end) {
+    UChar *min_semi_end, *max_semi_end;
+
+    if ((set->anchor & ANCR_BEGIN_POSITION) != 0) {
+      /* search start-position only */
+    begin_position:
+      range = start + 1;
+    }
+    else if ((set->anchor & ANCR_BEGIN_BUF) != 0) {
+      /* search str-position only */
+      if (start != str) goto mismatch_no_msa;
+      range = str + 1;
+    }
+    else if ((set->anchor & ANCR_END_BUF) != 0) {
+      min_semi_end = max_semi_end = (UChar* )end;
+
+    end_buf:
+      if ((OnigLen )(max_semi_end - str) < set->anc_dmin)
+        goto mismatch_no_msa;
+
+      if ((OnigLen )(min_semi_end - start) > set->anc_dmax) {
+        start = min_semi_end - set->anc_dmax;
+        if (start < end)
+          start = onigenc_get_right_adjust_char_head(enc, str, start);
+      }
+      if ((OnigLen )(max_semi_end - (range - 1)) < set->anc_dmin) {
+        range = max_semi_end - set->anc_dmin + 1;
+      }
+      if (start > range) goto mismatch_no_msa;
+    }
+    else if ((set->anchor & ANCR_SEMI_END_BUF) != 0) {
+      UChar* pre_end = ONIGENC_STEP_BACK(enc, str, end, 1);
+
+      max_semi_end = (UChar* )end;
+      if (ONIGENC_IS_MBC_NEWLINE(enc, pre_end, end)) {
+        min_semi_end = pre_end;
+
+#ifdef USE_CRNL_AS_LINE_TERMINATOR
+        pre_end = ONIGENC_STEP_BACK(enc, str, pre_end, 1);
+        if (IS_NOT_NULL(pre_end) &&
+            ONIGENC_IS_MBC_CRNL(enc, pre_end, end)) {
+          min_semi_end = pre_end;
+        }
 #endif
+        if (min_semi_end > str && start <= min_semi_end) {
+          goto end_buf;
+        }
+      }
+      else {
+        min_semi_end = (UChar* )end;
+        goto end_buf;
+      }
+    }
+    else if ((set->anchor & ANCR_ANYCHAR_INF_ML) != 0) {
+      goto begin_position;
+    }
+  }
+  else if (str == end) { /* empty string */
+    start = end = str;
+    s = (UChar* )start;
+    prev = (UChar* )NULL;
+
+    msas = (MatchArg* )xmalloc(sizeof(*msas) * set->n);
+    CHECK_NULL_RETURN_MEMERR(msas);
+    for (i = 0; i < set->n; i++) {
+      reg = set->rs[i].reg;
+      MATCH_ARG_INIT(msas[i], reg, option, set->rs[i].region, start, mps[i]);
+    }
+    for (i = 0; i < set->n; i++) {
+      reg = set->rs[i].reg;
+      if (reg->threshold_len == 0) {
+        REGSET_MATCH_AND_RETURN_CHECK(end);
+      }
+    }
+
+    goto mismatch;
+  }
+
+  if (lead == ONIG_REGSET_POSITION_LEAD) {
+    msas = (MatchArg* )xmalloc(sizeof(*msas) * set->n);
+    CHECK_NULL_RETURN_MEMERR(msas);
+
+    for (i = 0; i < set->n; i++) {
+      MATCH_ARG_INIT(msas[i], set->rs[i].reg, option, set->rs[i].region,
+                     orig_start, mps[i]);
+    }
+
+    r = regset_search_body_position_lead(set, str, end, start, range,
+                                         orig_range, option, msas, rmatch_pos);
+  }
+  else {
+    r = regset_search_body_regex_lead(set, str, end, start, orig_range,
+                                      lead, option, mps, rmatch_pos);
+  }
+  if (r < 0) goto finish;
+  else       goto match2;
+
+ mismatch:
+  r = ONIG_MISMATCH;
+ finish:
+  for (i = 0; i < set->n; i++) {
+    if (IS_NOT_NULL(msas))
+      MATCH_ARG_FREE(msas[i]);
+    if (IS_FIND_NOT_EMPTY(set->rs[i].reg->options) &&
+        IS_NOT_NULL(set->rs[i].region)) {
+      onig_region_clear(set->rs[i].region);
+    }
+  }
+  if (IS_NOT_NULL(msas)) xfree(msas);
+  return r;
+
+ mismatch_no_msa:
+  r = ONIG_MISMATCH;
+ finish_no_msa:
+  return r;
+
+ match:
+  *rmatch_pos = (int )(s - str);
+ match2:
+  for (i = 0; i < set->n; i++) {
+    if (IS_NOT_NULL(msas))
+      MATCH_ARG_FREE(msas[i]);
+    if (IS_FIND_NOT_EMPTY(set->rs[i].reg->options) &&
+        IS_NOT_NULL(set->rs[i].region)) {
+      onig_region_clear(set->rs[i].region);
+    }
+  }
+  if (IS_NOT_NULL(msas)) xfree(msas);
+  return r; /* regex index */
 }
 
+extern int
+onig_regset_search(OnigRegSet* set, const UChar* str, const UChar* end,
+                   const UChar* start, const UChar* range,
+                   OnigRegSetLead lead, OnigOptionType option, int* rmatch_pos)
+{
+  int r;
+  int i;
+  OnigMatchParam* mp;
+  OnigMatchParam** mps;
+
+  mps = (OnigMatchParam** )xmalloc((sizeof(OnigMatchParam*) + sizeof(OnigMatchParam)) * set->n);
+  CHECK_NULL_RETURN_MEMERR(mps);
+
+  mp = (OnigMatchParam* )(mps + set->n);
+
+  for (i = 0; i < set->n; i++) {
+    onig_initialize_match_param(mp + i);
+    mps[i] = mp + i;
+  }
+
+  r = onig_regset_search_with_param(set, str, end, start, range, lead, option, mps,
+                                    rmatch_pos);
+  for (i = 0; i < set->n; i++)
+    onig_free_match_param_content(mp + i);
+
+  xfree(mps);
+
+  return r;
+}
 
 static UChar*
 slow_search(OnigEncoding enc, UChar* target, UChar* target_end,
@@ -4193,9 +4665,11 @@ str_lower_case_match(OnigEncoding enc, int case_fold_flag,
   UChar *q, lowbuf[ONIGENC_MBC_CASE_FOLD_MAXLEN];
 
   while (t < tend) {
+    if (p >= end) return 0;
     lowlen = ONIGENC_MBC_CASE_FOLD(enc, case_fold_flag, &p, end, lowbuf);
     q = lowbuf;
     while (lowlen > 0) {
+      if (t >= tend)    return 0;
       if (*t++ != *q++) return 0;
       lowlen--;
     }
@@ -4209,16 +4683,11 @@ slow_search_ic(OnigEncoding enc, int case_fold_flag,
                UChar* target, UChar* target_end,
                const UChar* text, const UChar* text_end, UChar* text_range)
 {
-  UChar *s, *end;
-
-  end = (UChar* )text_end;
-  end -= target_end - target - 1;
-  if (end > text_range)
-    end = text_range;
+  UChar *s;
 
   s = (UChar* )text;
 
-  while (s < end) {
+  while (s < text_range) {
     if (str_lower_case_match(enc, case_fold_flag, target, target_end,
                              s, text_end))
       return s;
@@ -4372,60 +4841,6 @@ sunday_quick_search(regex_t* reg, const UChar* target, const UChar* target_end,
 }
 
 static UChar*
-sunday_quick_search_case_fold(regex_t* reg,
-                              const UChar* target, const UChar* target_end,
-                              const UChar* text,   const UChar* text_end,
-                              const UChar* text_range)
-{
-  const UChar *s, *se, *end;
-  const UChar *tail;
-  int skip, tlen1;
-  int map_offset;
-  int case_fold_flag;
-  OnigEncoding enc;
-
-#ifdef ONIG_DEBUG_SEARCH
-  fprintf(stderr,
-          "sunday_quick_search_case_fold: text: %p, text_end: %p, text_range: %p\n", text, text_end, text_range);
-#endif
-
-  enc = reg->enc;
-  case_fold_flag = reg->case_fold_flag;
-
-  tail = target_end - 1;
-  tlen1 = (int )(tail - target);
-  end = text_range;
-  if (end + tlen1 > text_end)
-    end = text_end - tlen1;
-
-  map_offset = reg->map_offset;
-  s = text;
-
-  while (s < end) {
-    if (str_lower_case_match(enc, case_fold_flag, target, target_end,
-                             s, text_end))
-      return (UChar* )s;
-
-    se = s + tlen1;
-    if (se + map_offset >= text_end) break;
-    skip = reg->map[*(se + map_offset)];
-#if 0
-    p = s;
-    do {
-      s += enclen(enc, s);
-    } while ((s - p) < skip && s < end);
-#else
-    /* This is faster than prev code for long text.  ex: /(?i)Twain/  */
-    s += skip;
-    if (s < end)
-      s = onigenc_get_right_adjust_char_head(enc, text, s);
-#endif
-  }
-
-  return (UChar* )NULL;
-}
-
-static UChar*
 map_search(OnigEncoding enc, UChar map[],
            const UChar* text, const UChar* text_range)
 {
@@ -4505,25 +4920,26 @@ onig_match_with_param(regex_t* reg, const UChar* str, const UChar* end,
 }
 
 static int
-forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
-                     UChar* range, UChar** low, UChar** high, UChar** low_prev)
+forward_search(regex_t* reg, const UChar* str, const UChar* end, UChar* start,
+               UChar* range, UChar** low, UChar** high, UChar** low_prev)
 {
   UChar *p, *pprev = (UChar* )NULL;
 
 #ifdef ONIG_DEBUG_SEARCH
-  fprintf(stderr, "forward_search_range: str: %p, end: %p, s: %p, range: %p\n",
-          str, end, s, range);
+  fprintf(stderr, "forward_search: str: %p, end: %p, start: %p, range: %p\n",
+          str, end, start, range);
 #endif
 
-  p = s;
-  if (reg->dmin > 0) {
+  p = start;
+  if (reg->dist_min != 0) {
+    if (end - p <= reg->dist_min)
+      return 0; /* fail */
+
     if (ONIGENC_IS_SINGLEBYTE(reg->enc)) {
-      p += reg->dmin;
+      p += reg->dist_min;
     }
     else {
-      UChar *q = p + reg->dmin;
-
-      if (q >= end) return 0; /* fail */
+      UChar *q = p + reg->dist_min;
       while (p < q) p += enclen(reg->enc, p);
     }
   }
@@ -4538,11 +4954,6 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
                        reg->exact, reg->exact_end, p, end, range);
     break;
 
-  case OPTIMIZE_STR_CASE_FOLD_FAST:
-    p = sunday_quick_search_case_fold(reg, reg->exact, reg->exact_end, p, end,
-                                      range);
-    break;
-
   case OPTIMIZE_STR_FAST:
     p = sunday_quick_search(reg, reg->exact, reg->exact_end, p, end, range);
     break;
@@ -4558,7 +4969,7 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
   }
 
   if (p && p < range) {
-    if (p - reg->dmin < s) {
+    if (p - start < reg->dist_min) {
     retry_gate:
       pprev = p;
       p += enclen(reg->enc, p);
@@ -4571,8 +4982,7 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
       switch (reg->sub_anchor) {
       case ANCR_BEGIN_LINE:
         if (!ON_STR_BEGIN(p)) {
-          prev = onigenc_get_prev_char_head(reg->enc,
-                                            (pprev ? pprev : str), p);
+          prev = onigenc_get_prev_char_head(reg->enc, (pprev ? pprev : str), p);
           if (!ONIGENC_IS_MBC_NEWLINE(reg->enc, prev, end))
             goto retry_gate;
         }
@@ -4593,35 +5003,34 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
 #endif
                  )
           goto retry_gate;
+
         break;
       }
     }
 
-    if (reg->dmax == 0) {
+    if (reg->dist_max == 0) {
       *low = p;
       if (low_prev) {
-        if (*low > s)
-          *low_prev = onigenc_get_prev_char_head(reg->enc, s, p);
+        if (*low > start)
+          *low_prev = onigenc_get_prev_char_head(reg->enc, start, p);
         else
           *low_prev = onigenc_get_prev_char_head(reg->enc,
                                                  (pprev ? pprev : str), p);
       }
+      *high = p;
     }
     else {
-      if (reg->dmax != INFINITE_LEN) {
-        if (p - str < reg->dmax) {
+      if (reg->dist_max != INFINITE_LEN) {
+        if (p - str < reg->dist_max) {
           *low = (UChar* )str;
           if (low_prev)
             *low_prev = onigenc_get_prev_char_head(reg->enc, str, *low);
         }
         else {
-          *low = p - reg->dmax;
-          if (*low > s) {
-            *low = onigenc_get_right_adjust_char_head_with_prev(reg->enc, s,
+          *low = p - reg->dist_max;
+          if (*low > start) {
+            *low = onigenc_get_right_adjust_char_head_with_prev(reg->enc, start,
                                                  *low, (const UChar** )low_prev);
-            if (low_prev && IS_NULL(*low_prev))
-              *low_prev = onigenc_get_prev_char_head(reg->enc,
-                                                     (pprev ? pprev : s), *low);
           }
           else {
             if (low_prev)
@@ -4630,14 +5039,18 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
           }
         }
       }
+      /* no needs to adjust *high, *high is used as range check only */
+      if (p - str < reg->dist_min)
+        *high = (UChar* )str;
+      else
+        *high = p - reg->dist_min;
     }
-    /* no needs to adjust *high, *high is used as range check only */
-    *high = p - reg->dmin;
 
 #ifdef ONIG_DEBUG_SEARCH
     fprintf(stderr,
-            "forward_search_range success: low: %d, high: %d, dmin: %d, dmax: %d\n",
-            (int )(*low - str), (int )(*high - str), reg->dmin, reg->dmax);
+            "forward_search success: low: %d, high: %d, dmin: %u, dmax: %u\n",
+            (int )(*low - str), (int )(*high - str),
+            reg->dist_min, reg->dist_max);
 #endif
     return 1; /* success */
   }
@@ -4647,15 +5060,11 @@ forward_search_range(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
 
 
 static int
-backward_search_range(regex_t* reg, const UChar* str, const UChar* end,
-                      UChar* s, const UChar* range, UChar* adjrange,
-                      UChar** low, UChar** high)
+backward_search(regex_t* reg, const UChar* str, const UChar* end, UChar* s,
+                const UChar* range, UChar* adjrange, UChar** low, UChar** high)
 {
   UChar *p;
 
-  if (range == 0) goto fail;
-
-  range += reg->dmin;
   p = s;
 
  retry:
@@ -4667,7 +5076,6 @@ backward_search_range(regex_t* reg, const UChar* str, const UChar* end,
     break;
 
   case OPTIMIZE_STR_CASE_FOLD:
-  case OPTIMIZE_STR_CASE_FOLD_FAST:
     p = slow_search_backward_ic(reg->enc, reg->case_fold_flag,
                                 reg->exact, reg->exact_end,
                                 range, adjrange, end, p);
@@ -4722,15 +5130,27 @@ backward_search_range(regex_t* reg, const UChar* str, const UChar* end,
       }
     }
 
-    /* no needs to adjust *high, *high is used as range check only */
-    if (reg->dmax != INFINITE_LEN) {
-      *low  = p - reg->dmax;
-      *high = p - reg->dmin;
+    if (reg->dist_max != INFINITE_LEN) {
+      if (p - str < reg->dist_max)
+        *low = (UChar* )str;
+      else
+        *low = p - reg->dist_max;
+
+      if (reg->dist_min != 0) {
+        if (p - str < reg->dist_min)
+          *high = (UChar* )str;
+        else
+          *high = p - reg->dist_min;
+      }
+      else {
+        *high = p;
+      }
+
       *high = onigenc_get_right_adjust_char_head(reg->enc, adjrange, *high);
     }
 
 #ifdef ONIG_DEBUG_SEARCH
-    fprintf(stderr, "backward_search_range: low: %d, high: %d\n",
+    fprintf(stderr, "backward_search: low: %d, high: %d\n",
             (int )(*low - str), (int )(*high - str));
 #endif
     return 1; /* success */
@@ -4738,7 +5158,7 @@ backward_search_range(regex_t* reg, const UChar* str, const UChar* end,
 
  fail:
 #ifdef ONIG_DEBUG_SEARCH
-  fprintf(stderr, "backward_search_range: fail.\n");
+  fprintf(stderr, "backward_search: fail.\n");
 #endif
   return 0; /* fail */
 }
@@ -4751,24 +5171,35 @@ onig_search(regex_t* reg, const UChar* str, const UChar* end,
 {
   int r;
   OnigMatchParam mp;
+  const UChar* data_range;
 
   onig_initialize_match_param(&mp);
-  r = onig_search_with_param(reg, str, end, start, range, region, option, &mp);
+
+  /* The following is an expanded code of onig_search_with_param()  */
+  if (range > start)
+    data_range = range;
+  else
+    data_range = end;
+
+  r = search_in_range(reg, str, end, start, range, data_range, region,
+                      option, &mp);
+
   onig_free_match_param_content(&mp);
   return r;
 
 }
 
-extern int
-onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
-                       const UChar* start, const UChar* range, OnigRegion* region,
-                       OnigOptionType option, OnigMatchParam* mp)
+static int
+search_in_range(regex_t* reg, const UChar* str, const UChar* end,
+                const UChar* start, const UChar* range, /* match start range */
+                const UChar* data_range, /* subject string range */
+                OnigRegion* region,
+                OnigOptionType option, OnigMatchParam* mp)
 {
   int r;
   UChar *s, *prev;
   MatchArg msa;
   const UChar *orig_start = start;
-  const UChar *orig_range = range;
 
 #ifdef ONIG_DEBUG_SEARCH
   fprintf(stderr,
@@ -4851,17 +5282,21 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
       min_semi_end = max_semi_end = (UChar* )end;
 
     end_buf:
-      if ((OnigLen )(max_semi_end - str) < reg->anchor_dmin)
+      if ((OnigLen )(max_semi_end - str) < reg->anc_dist_min)
         goto mismatch_no_msa;
 
       if (range > start) {
-        if ((OnigLen )(min_semi_end - start) > reg->anchor_dmax) {
-          start = min_semi_end - reg->anchor_dmax;
+        if (reg->anc_dist_max != INFINITE_LEN &&
+            min_semi_end - start > reg->anc_dist_max) {
+          start = min_semi_end - reg->anc_dist_max;
           if (start < end)
             start = onigenc_get_right_adjust_char_head(reg->enc, str, start);
         }
-        if ((OnigLen )(max_semi_end - (range - 1)) < reg->anchor_dmin) {
-          range = max_semi_end - reg->anchor_dmin + 1;
+        if (max_semi_end - (range - 1) < reg->anc_dist_min) {
+          if (max_semi_end - str + 1 < reg->anc_dist_min)
+            goto mismatch_no_msa;
+          else
+            range = max_semi_end - reg->anc_dist_min + 1;
         }
 
         if (start > range) goto mismatch_no_msa;
@@ -4869,12 +5304,17 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
            Backward search is used. */
       }
       else {
-        if ((OnigLen )(min_semi_end - range) > reg->anchor_dmax) {
-          range = min_semi_end - reg->anchor_dmax;
+        if (reg->anc_dist_max != INFINITE_LEN &&
+            min_semi_end - range > reg->anc_dist_max) {
+          range = min_semi_end - reg->anc_dist_max;
         }
-        if ((OnigLen )(max_semi_end - start) < reg->anchor_dmin) {
-          start = max_semi_end - reg->anchor_dmin;
-          start = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc, str, start);
+        if (max_semi_end - start < reg->anc_dist_min) {
+          if (max_semi_end - str < reg->anc_dist_min)
+            goto mismatch_no_msa;
+          else {
+            start = max_semi_end - reg->anc_dist_min;
+            start = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc, str, start);
+          }
         }
         if (range > start) goto mismatch_no_msa;
       }
@@ -4942,29 +5382,33 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
     if (reg->optimize != OPTIMIZE_NONE) {
       UChar *sch_range, *low, *high, *low_prev;
 
-      sch_range = (UChar* )range;
-      if (reg->dmax != 0) {
-        if (reg->dmax == INFINITE_LEN)
+      if (reg->dist_max != 0) {
+        if (reg->dist_max == INFINITE_LEN)
           sch_range = (UChar* )end;
         else {
-          sch_range += reg->dmax;
-          if (sch_range > end) sch_range = (UChar* )end;
+          if ((end - range) < reg->dist_max)
+            sch_range = (UChar* )end;
+          else {
+            sch_range = (UChar* )range + reg->dist_max;
+          }
         }
       }
+      else
+        sch_range = (UChar* )range;
 
       if ((end - start) < reg->threshold_len)
         goto mismatch;
 
-      if (reg->dmax != INFINITE_LEN) {
+      if (reg->dist_max != INFINITE_LEN) {
         do {
-          if (! forward_search_range(reg, str, end, s, sch_range,
-                                     &low, &high, &low_prev)) goto mismatch;
+          if (! forward_search(reg, str, end, s, sch_range, &low, &high,
+                               &low_prev)) goto mismatch;
           if (s < low) {
             s    = low;
             prev = low_prev;
           }
           while (s <= high) {
-            MATCH_AND_RETURN_CHECK(orig_range);
+            MATCH_AND_RETURN_CHECK(data_range);
             prev = s;
             s += enclen(reg->enc, s);
           }
@@ -4972,12 +5416,12 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
         goto mismatch;
       }
       else { /* check only. */
-        if (! forward_search_range(reg, str, end, s, sch_range,
-                                   &low, &high, (UChar** )NULL)) goto mismatch;
+        if (! forward_search(reg, str, end, s, sch_range, &low, &high,
+                             (UChar** )NULL)) goto mismatch;
 
         if ((reg->anchor & ANCR_ANYCHAR_INF) != 0) {
           do {
-            MATCH_AND_RETURN_CHECK(orig_range);
+            MATCH_AND_RETURN_CHECK(data_range);
             prev = s;
             s += enclen(reg->enc, s);
 
@@ -4994,13 +5438,13 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
     }
 
     do {
-      MATCH_AND_RETURN_CHECK(orig_range);
+      MATCH_AND_RETURN_CHECK(data_range);
       prev = s;
       s += enclen(reg->enc, s);
     } while (s < range);
 
     if (s == range) { /* because empty match with /$/. */
-      MATCH_AND_RETURN_CHECK(orig_range);
+      MATCH_AND_RETURN_CHECK(data_range);
     }
   }
   else {  /* backward search */
@@ -5011,19 +5455,30 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
 
     if (reg->optimize != OPTIMIZE_NONE) {
       UChar *low, *high, *adjrange, *sch_start;
+      const UChar *min_range;
+
+      if ((end - range) < reg->threshold_len) goto mismatch;
 
       if (range < end)
         adjrange = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc, str, range);
       else
         adjrange = (UChar* )end;
 
-      if (reg->dmax != INFINITE_LEN &&
-          (end - range) >= reg->threshold_len) {
+      if (end - range > reg->dist_min)
+        min_range = range + reg->dist_min;
+      else
+        min_range = end;
+
+      if (reg->dist_max != INFINITE_LEN) {
         do {
-          sch_start = s + reg->dmax;
-          if (sch_start > end) sch_start = (UChar* )end;
-          if (backward_search_range(reg, str, end, sch_start, range, adjrange,
-                                    &low, &high) <= 0)
+          if (end - s > reg->dist_max)
+            sch_start = s + reg->dist_max;
+          else {
+            sch_start = onigenc_get_prev_char_head(reg->enc, str, end);
+          }
+
+          if (backward_search(reg, str, end, sch_start, min_range, adjrange,
+                              &low, &high) <= 0)
             goto mismatch;
 
           if (s > high)
@@ -5038,22 +5493,10 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
         goto mismatch;
       }
       else { /* check only. */
-        if ((end - range) < reg->threshold_len) goto mismatch;
+        sch_start = onigenc_get_prev_char_head(reg->enc, str, end);
 
-        sch_start = s;
-        if (reg->dmax != 0) {
-          if (reg->dmax == INFINITE_LEN)
-            sch_start = (UChar* )end;
-          else {
-            sch_start += reg->dmax;
-            if (sch_start > end) sch_start = (UChar* )end;
-            else
-              sch_start = ONIGENC_LEFT_ADJUST_CHAR_HEAD(reg->enc,
-                                                        start, sch_start);
-          }
-        }
-        if (backward_search_range(reg, str, end, sch_start, range, adjrange,
-                                  &low, &high) <= 0) goto mismatch;
+        if (backward_search(reg, str, end, sch_start, min_range, adjrange,
+                            &low, &high) <= 0) goto mismatch;
       }
     }
 
@@ -5109,6 +5552,22 @@ onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
 }
 
 extern int
+onig_search_with_param(regex_t* reg, const UChar* str, const UChar* end,
+                       const UChar* start, const UChar* range, OnigRegion* region,
+                       OnigOptionType option, OnigMatchParam* mp)
+{
+  const UChar* data_range;
+
+  if (range > start)
+    data_range = range;
+  else
+    data_range = end;
+
+  return search_in_range(reg, str, end, start, range, data_range, region,
+                         option, mp);
+}
+
+extern int
 onig_scan(regex_t* reg, const UChar* str, const UChar* end,
           OnigRegion* region, OnigOptionType option,
           int (*scan_callback)(int, int, OnigRegion*, void*),
@@ -5210,6 +5669,202 @@ onig_copy_encoding(OnigEncoding to, OnigEncoding from)
   *to = *from;
 }
 
+extern int
+onig_regset_new(OnigRegSet** rset, int n, regex_t* regs[])
+{
+#define REGSET_INITIAL_ALLOC_SIZE   10
+
+  int i;
+  int r;
+  int alloc;
+  OnigRegSet* set;
+  RR* rs;
+
+  *rset = 0;
+
+  set = (OnigRegSet* )xmalloc(sizeof(*set));
+  CHECK_NULL_RETURN_MEMERR(set);
+
+  alloc = n > REGSET_INITIAL_ALLOC_SIZE ? n : REGSET_INITIAL_ALLOC_SIZE;
+  rs = (RR* )xmalloc(sizeof(set->rs[0]) * alloc);
+  if (IS_NULL(rs)) {
+    xfree(set);
+    return ONIGERR_MEMORY;
+  }
+
+  set->rs    = rs;
+  set->n     = 0;
+  set->alloc = alloc;
+
+  for (i = 0; i < n; i++) {
+    regex_t* reg = regs[i];
+
+    r = onig_regset_add(set, reg);
+    if (r != 0) {
+      for (i = 0; i < set->n; i++) {
+        OnigRegion* region = set->rs[i].region;
+        if (IS_NOT_NULL(region))
+          onig_region_free(region, 1);
+      }
+      xfree(set->rs);
+      xfree(set);
+      return r;
+    }
+  }
+
+  *rset = set;
+  return 0;
+}
+
+static void
+update_regset_by_reg(OnigRegSet* set, regex_t* reg)
+{
+  if (set->n == 1) {
+    set->enc          = reg->enc;
+    set->anchor       = reg->anchor;
+    set->anc_dmin     = reg->anc_dist_min;
+    set->anc_dmax     = reg->anc_dist_max;
+    set->all_low_high =
+      (reg->optimize == OPTIMIZE_NONE || reg->dist_max == INFINITE_LEN) ? 0 : 1;
+    set->anychar_inf  = (reg->anchor & ANCR_ANYCHAR_INF) != 0 ? 1 : 0;
+  }
+  else {
+    int anchor;
+
+    anchor = set->anchor & reg->anchor;
+    if (anchor != 0) {
+      OnigLen anc_dmin;
+      OnigLen anc_dmax;
+
+      anc_dmin = set->anc_dmin;
+      anc_dmax = set->anc_dmax;
+      if (anc_dmin > reg->anc_dist_min) anc_dmin = reg->anc_dist_min;
+      if (anc_dmax < reg->anc_dist_max) anc_dmax = reg->anc_dist_max;
+      set->anc_dmin = anc_dmin;
+      set->anc_dmax = anc_dmax;
+    }
+
+    set->anchor = anchor;
+
+    if (reg->optimize == OPTIMIZE_NONE || reg->dist_max == INFINITE_LEN)
+      set->all_low_high = 0;
+
+    if ((reg->anchor & ANCR_ANYCHAR_INF) != 0)
+      set->anychar_inf = 1;
+  }
+}
+
+extern int
+onig_regset_add(OnigRegSet* set, regex_t* reg)
+{
+  OnigRegion* region;
+
+  if (IS_FIND_LONGEST(reg->options))
+    return ONIGERR_INVALID_ARGUMENT;
+
+  if (set->n != 0 && reg->enc != set->enc)
+    return ONIGERR_INVALID_ARGUMENT;
+
+  if (set->n >= set->alloc) {
+    RR* nrs;
+    int new_alloc;
+
+    new_alloc = set->alloc * 2;
+    nrs = (RR* )xrealloc(set->rs, sizeof(set->rs[0]) * new_alloc);
+    CHECK_NULL_RETURN_MEMERR(nrs);
+
+    set->rs    = nrs;
+    set->alloc = new_alloc;
+  }
+
+  region = onig_region_new();
+  CHECK_NULL_RETURN_MEMERR(region);
+
+  set->rs[set->n].reg    = reg;
+  set->rs[set->n].region = region;
+  set->n++;
+
+  update_regset_by_reg(set, reg);
+  return 0;
+}
+
+extern int
+onig_regset_replace(OnigRegSet* set, int at, regex_t* reg)
+{
+  int i;
+
+  if (at < 0 || at >= set->n)
+    return ONIGERR_INVALID_ARGUMENT;
+
+  if (IS_NULL(reg)) {
+    onig_region_free(set->rs[at].region, 1);
+    for (i = at; i < set->n - 1; i++) {
+      set->rs[i].reg    = set->rs[i+1].reg;
+      set->rs[i].region = set->rs[i+1].region;
+    }
+    set->n--;
+  }
+  else {
+    if (IS_FIND_LONGEST(reg->options))
+      return ONIGERR_INVALID_ARGUMENT;
+
+    if (set->n > 1 && reg->enc != set->enc)
+      return ONIGERR_INVALID_ARGUMENT;
+
+    set->rs[at].reg = reg;
+  }
+
+  for (i = 0; i < set->n; i++)
+    update_regset_by_reg(set, set->rs[i].reg);
+
+  return 0;
+}
+
+extern void
+onig_regset_free(OnigRegSet* set)
+{
+  int i;
+
+  for (i = 0; i < set->n; i++) {
+    regex_t* reg;
+    OnigRegion* region;
+
+    reg    = set->rs[i].reg;
+    region = set->rs[i].region;
+    onig_free(reg);
+    if (IS_NOT_NULL(region))
+      onig_region_free(region, 1);
+  }
+
+  xfree(set->rs);
+  xfree(set);
+}
+
+extern int
+onig_regset_number_of_regex(OnigRegSet* set)
+{
+  return set->n;
+}
+
+extern regex_t*
+onig_regset_get_regex(OnigRegSet* set, int at)
+{
+  if (at < 0 || at >= set->n)
+    return (regex_t* )0;
+
+  return set->rs[at].reg;
+}
+
+extern OnigRegion*
+onig_regset_get_region(OnigRegSet* set, int at)
+{
+  if (at < 0 || at >= set->n)
+    return (OnigRegion* )0;
+
+  return set->rs[at].region;
+}
+
+
 #ifdef USE_DIRECT_THREADED_CODE
 extern int
 onig_init_for_match_at(regex_t* reg)
@@ -5402,35 +6057,25 @@ onig_get_capture_range_in_callout(OnigCalloutArgs* a, int mem_num, int* begin, i
   const UChar* str;
   StackType*   stk_base;
   int i;
+  StackIndex* mem_start_stk;
+  StackIndex* mem_end_stk;
 
   i = mem_num;
   reg = a->regex;
   str = a->string;
   stk_base = a->stk_base;
+  mem_start_stk = a->mem_start_stk;
+  mem_end_stk   = a->mem_end_stk;
 
   if (i > 0) {
     if (a->mem_end_stk[i] != INVALID_STACK_INDEX) {
-      if (MEM_STATUS_AT(reg->bt_mem_start, i))
-        *begin = (int )(STACK_AT(a->mem_start_stk[i])->u.mem.pstr - str);
-      else
-        *begin = (int )((UChar* )((void* )a->mem_start_stk[i]) - str);
-
-      *end = (int )((MEM_STATUS_AT(reg->bt_mem_end, i)
-                     ? STACK_AT(a->mem_end_stk[i])->u.mem.pstr
-                     : (UChar* )((void* )a->mem_end_stk[i])) - str);
+      *begin = (int )(STACK_MEM_START(reg, i) - str);
+      *end   = (int )(STACK_MEM_END(reg, i)   - str);
     }
     else {
       *begin = *end = ONIG_REGION_NOTPOS;
     }
   }
-  else if (i == 0) {
-#if 0
-    *begin = a->start   - str;
-    *end   = a->current - str;
-#else
-    return ONIGERR_INVALID_ARGUMENT;
-#endif
-  }
   else
     return ONIGERR_INVALID_ARGUMENT;
 
@@ -5468,14 +6113,6 @@ onig_builtin_mismatch(OnigCalloutArgs* args ARG_UNUSED, void* user_data ARG_UNUS
   return ONIG_MISMATCH;
 }
 
-#if 0
-extern int
-onig_builtin_success(OnigCalloutArgs* args ARG_UNUSED, void* user_data ARG_UNUSED)
-{
-  return ONIG_CALLOUT_SUCCESS;
-}
-#endif
-
 extern int
 onig_builtin_error(OnigCalloutArgs* args, void* user_data ARG_UNUSED)
 {
diff --git a/src/regext.c b/src/regext.c
index 965c793..c46f630 100644
--- a/src/regext.c
+++ b/src/regext.c
@@ -2,7 +2,7 @@
   regext.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/reggnu.c b/src/reggnu.c
index a124ae8..8a45078 100644
--- a/src/reggnu.c
+++ b/src/reggnu.c
@@ -2,7 +2,7 @@
   reggnu.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/regint.h b/src/regint.h
index 38389a1..cc540da 100644
--- a/src/regint.h
+++ b/src/regint.h
@@ -4,7 +4,7 @@
   regint.h -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,16 +47,11 @@
 #endif
 #endif
 
-#if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
-    (defined(__ppc__) && defined(__APPLE__)) || \
-    defined(__x86_64) || defined(__x86_64__) || \
-    defined(__mc68020__)
-#define PLATFORM_UNALIGNED_WORD_ACCESS
-#endif
-
+#ifndef ONIG_DISABLE_DIRECT_THREADING
 #ifdef __GNUC__
 #define USE_GOTO_LABELS_AS_VALUES
 #endif
+#endif
 
 /* config */
 /* spec. config */
@@ -82,6 +77,8 @@
 #define USE_VARIABLE_META_CHARS
 #define USE_POSIX_API_REGION_OPTION
 #define USE_FIND_LONGEST_SEARCH_ALL_OF_RANGE
+/* #define USE_REPEAT_AND_EMPTY_CHECK_LOCAL_VAR */
+
 
 #include "regenc.h"
 
@@ -197,49 +194,16 @@ typedef unsigned int  uintptr_t;
 #define CHAR_MAP_SIZE       256
 #define INFINITE_LEN        ONIG_INFINITE_DISTANCE
 
-#ifdef PLATFORM_UNALIGNED_WORD_ACCESS
-
-#define PLATFORM_GET_INC(val,p,type) do{\
-  val  = *(type* )p;\
-  (p) += sizeof(type);\
-} while(0)
-
-#else
-
-#define PLATFORM_GET_INC(val,p,type) do{\
-  xmemcpy(&val, (p), sizeof(type));\
-  (p) += sizeof(type);\
-} while(0)
-
-/* sizeof(OnigCodePoint) */
-#ifdef SIZEOF_SIZE_T
-# define WORD_ALIGNMENT_SIZE     SIZEOF_SIZE_T
-#else
-# define WORD_ALIGNMENT_SIZE     SIZEOF_LONG
-#endif
-
-#define GET_ALIGNMENT_PAD_SIZE(addr,pad_size) do {\
-  (pad_size) = WORD_ALIGNMENT_SIZE - ((uintptr_t )(addr) % WORD_ALIGNMENT_SIZE);\
-  if ((pad_size) == WORD_ALIGNMENT_SIZE) (pad_size) = 0;\
-} while (0)
-
-#define ALIGNMENT_RIGHT(addr) do {\
-  (addr) += (WORD_ALIGNMENT_SIZE - 1);\
-  (addr) -= ((uintptr_t )(addr) % WORD_ALIGNMENT_SIZE);\
-} while (0)
-
-#endif /* PLATFORM_UNALIGNED_WORD_ACCESS */
-
 
 #ifdef USE_CALLOUT
 
 typedef struct {
-  int           flag;
-  OnigCalloutOf of;
-  int           in;
-  int           name_id;
-  const UChar*  tag_start;
-  const UChar*  tag_end;
+  int             flag;
+  OnigCalloutOf   of;
+  int             in;
+  int             name_id;
+  const UChar*    tag_start;
+  const UChar*    tag_end;
   OnigCalloutType type;
   OnigCalloutFunc start_func;
   OnigCalloutFunc end_func;
@@ -272,7 +236,6 @@ enum OptimizeType {
   OPTIMIZE_STR,                   /* Slow Search */
   OPTIMIZE_STR_FAST,              /* Sunday quick search / BMH */
   OPTIMIZE_STR_FAST_STEP_FORWARD, /* Sunday quick search / BMH */
-  OPTIMIZE_STR_CASE_FOLD_FAST,    /* Sunday quick search / BMH (ignore case) */
   OPTIMIZE_STR_CASE_FOLD,         /* Slow Search (ignore case) */
   OPTIMIZE_MAP                    /* char map */
 };
@@ -288,6 +251,8 @@ typedef unsigned int  MemStatusType;
 #define MEM_STATUS_AT0(stats,n) \
   ((n) > 0 && (n) < (int )MEM_STATUS_BITS_NUM  ?  ((stats) & ((MemStatusType )1 << n)) : ((stats) & 1))
 
+#define MEM_STATUS_IS_ALL_ON(stats)  (((stats) & 1) != 0)
+
 #define MEM_STATUS_ON(stats,n) do {\
   if ((n) < (int )MEM_STATUS_BITS_NUM) {\
     if ((n) != 0)\
@@ -302,8 +267,14 @@ typedef unsigned int  MemStatusType;
     (stats) |= ((MemStatusType )1 << (n));\
 } while (0)
 
+#define MEM_STATUS_LIMIT_AT(stats,n) \
+  ((n) < (int )MEM_STATUS_BITS_NUM  ?  ((stats) & ((MemStatusType )1 << n)) : 0)
+#define MEM_STATUS_LIMIT_ON(stats,n) do {\
+  if ((n) < (int )MEM_STATUS_BITS_NUM && (n) != 0) {\
+    (stats) |= ((MemStatusType )1 << (n));\
+  }\
+} while (0)
 
-#define INT_MAX_LIMIT           ((1UL << (SIZEOF_INT * 8 - 1)) - 1)
 
 #define IS_CODE_WORD_ASCII(enc,code) \
   (ONIGENC_IS_CODE_ASCII(code) && ONIGENC_IS_CODE_WORD(enc,code))
@@ -354,16 +325,12 @@ typedef unsigned int  MemStatusType;
 /* bitset */
 #define BITS_PER_BYTE      8
 #define SINGLE_BYTE_SIZE   (1 << BITS_PER_BYTE)
-#define BITS_IN_ROOM       (sizeof(Bits) * BITS_PER_BYTE)
+#define BITS_IN_ROOM       32   /* 4 * BITS_PER_BYTE */
 #define BITSET_SIZE        (SINGLE_BYTE_SIZE / BITS_IN_ROOM)
 
-#ifdef PLATFORM_UNALIGNED_WORD_ACCESS
-typedef unsigned int   Bits;
-#else
-typedef unsigned char  Bits;
-#endif
-typedef Bits           BitSet[BITSET_SIZE];
-typedef Bits*          BitSetRef;
+typedef uint32_t  Bits;
+typedef Bits      BitSet[BITSET_SIZE];
+typedef Bits*     BitSetRef;
 
 #define SIZE_BITSET        sizeof(BitSet)
 
@@ -372,8 +339,8 @@ typedef Bits*          BitSetRef;
   for (i = 0; i < (int )BITSET_SIZE; i++) { (bs)[i] = 0; } \
 } while (0)
 
-#define BS_ROOM(bs,pos)            (bs)[pos / BITS_IN_ROOM]
-#define BS_BIT(pos)                (1 << (pos % BITS_IN_ROOM))
+#define BS_ROOM(bs,pos)            (bs)[(unsigned int )(pos) >> 5]
+#define BS_BIT(pos)                (1u << ((unsigned int )(pos) & 0x1f))
 
 #define BITSET_AT(bs, pos)         (BS_ROOM(bs,pos) & BS_BIT(pos))
 #define BITSET_SET_BIT(bs, pos)     BS_ROOM(bs,pos) |= BS_BIT(pos)
@@ -389,11 +356,13 @@ typedef struct _BBuf {
 
 #define BB_INIT(buf,size)    bbuf_init((BBuf* )(buf), (size))
 
+/*
 #define BB_SIZE_INC(buf,inc) do{\
   (buf)->alloc += (inc);\
   (buf)->p = (UChar* )xrealloc((buf)->p, (buf)->alloc);\
   if (IS_NULL((buf)->p)) return(ONIGERR_MEMORY);\
 } while (0)
+*/
 
 #define BB_EXPAND(buf,low) do{\
   do { (buf)->alloc *= 2; } while ((buf)->alloc < (unsigned int )low);\
@@ -491,39 +460,34 @@ typedef struct _BBuf {
 
 /* operation code */
 enum OpCode {
-  OP_FINISH = 0,        /* matching process terminator (no more alternative) */
-  OP_END    = 1,        /* pattern code terminator (success end) */
-
-  OP_EXACT1 = 2,        /* single byte, N = 1 */
-  OP_EXACT2,            /* single byte, N = 2 */
-  OP_EXACT3,            /* single byte, N = 3 */
-  OP_EXACT4,            /* single byte, N = 4 */
-  OP_EXACT5,            /* single byte, N = 5 */
-  OP_EXACTN,            /* single byte */
-  OP_EXACTMB2N1,        /* mb-length = 2 N = 1 */
-  OP_EXACTMB2N2,        /* mb-length = 2 N = 2 */
-  OP_EXACTMB2N3,        /* mb-length = 2 N = 3 */
-  OP_EXACTMB2N,         /* mb-length = 2 */
-  OP_EXACTMB3N,         /* mb-length = 3 */
-  OP_EXACTMBN,          /* other length */
-
-  OP_EXACT1_IC,         /* single byte, N = 1, ignore case */
-  OP_EXACTN_IC,         /* single byte,        ignore case */
-
+  OP_FINISH = 0,       /* matching process terminator (no more alternative) */
+  OP_END    = 1,       /* pattern code terminator (success end) */
+  OP_STR_1 = 2,        /* single byte, N = 1 */
+  OP_STR_2,            /* single byte, N = 2 */
+  OP_STR_3,            /* single byte, N = 3 */
+  OP_STR_4,            /* single byte, N = 4 */
+  OP_STR_5,            /* single byte, N = 5 */
+  OP_STR_N,            /* single byte */
+  OP_STR_MB2N1,        /* mb-length = 2 N = 1 */
+  OP_STR_MB2N2,        /* mb-length = 2 N = 2 */
+  OP_STR_MB2N3,        /* mb-length = 2 N = 3 */
+  OP_STR_MB2N,         /* mb-length = 2 */
+  OP_STR_MB3N,         /* mb-length = 3 */
+  OP_STR_MBN,          /* other length */
+  OP_STR_1_IC,         /* single byte, N = 1, ignore case */
+  OP_STR_N_IC,         /* single byte,        ignore case */
   OP_CCLASS,
   OP_CCLASS_MB,
   OP_CCLASS_MIX,
   OP_CCLASS_NOT,
   OP_CCLASS_MB_NOT,
   OP_CCLASS_MIX_NOT,
-
   OP_ANYCHAR,                 /* "."  */
   OP_ANYCHAR_ML,              /* "."  multi-line */
   OP_ANYCHAR_STAR,            /* ".*" */
   OP_ANYCHAR_ML_STAR,         /* ".*" multi-line */
   OP_ANYCHAR_STAR_PEEK_NEXT,
   OP_ANYCHAR_ML_STAR_PEEK_NEXT,
-
   OP_WORD,
   OP_WORD_ASCII,
   OP_NO_WORD,
@@ -532,16 +496,13 @@ enum OpCode {
   OP_NO_WORD_BOUNDARY,
   OP_WORD_BEGIN,
   OP_WORD_END,
-
   OP_TEXT_SEGMENT_BOUNDARY,
-
   OP_BEGIN_BUF,
   OP_END_BUF,
   OP_BEGIN_LINE,
   OP_END_LINE,
   OP_SEMI_END_BUF,
   OP_BEGIN_POSITION,
-
   OP_BACKREF1,
   OP_BACKREF2,
   OP_BACKREF_N,
@@ -552,34 +513,35 @@ enum OpCode {
   OP_BACKREF_WITH_LEVEL_IC,     /* \k<xxx+n>, \k<xxx-n> */
   OP_BACKREF_CHECK,             /* (?(n)), (?('name')) */
   OP_BACKREF_CHECK_WITH_LEVEL,  /* (?(n-level)), (?('name-level')) */
-
-  OP_MEMORY_START,
-  OP_MEMORY_START_PUSH,   /* push back-tracker to stack */
-  OP_MEMORY_END_PUSH,     /* push back-tracker to stack */
-  OP_MEMORY_END_PUSH_REC, /* push back-tracker to stack */
-  OP_MEMORY_END,
-  OP_MEMORY_END_REC,      /* push marker to stack */
-
+  OP_MEM_START,
+  OP_MEM_START_PUSH,     /* push back-tracker to stack */
+  OP_MEM_END_PUSH,       /* push back-tracker to stack */
+#ifdef USE_CALL
+  OP_MEM_END_PUSH_REC,   /* push back-tracker to stack */
+#endif
+  OP_MEM_END,
+#ifdef USE_CALL
+  OP_MEM_END_REC,        /* push marker to stack */
+#endif
   OP_FAIL,               /* pop stack and move */
   OP_JUMP,
   OP_PUSH,
   OP_PUSH_SUPER,
   OP_POP_OUT,
 #ifdef USE_OP_PUSH_OR_JUMP_EXACT
-  OP_PUSH_OR_JUMP_EXACT1,  /* if match exact then push, else jump. */
+  OP_PUSH_OR_JUMP_EXACT1,   /* if match exact then push, else jump. */
 #endif
-  OP_PUSH_IF_PEEK_NEXT,    /* if match exact then push, else none. */
-  OP_REPEAT,               /* {n,m} */
-  OP_REPEAT_NG,            /* {n,m}? (non greedy) */
+  OP_PUSH_IF_PEEK_NEXT,     /* if match exact then push, else none. */
+  OP_REPEAT,                /* {n,m} */
+  OP_REPEAT_NG,             /* {n,m}? (non greedy) */
   OP_REPEAT_INC,
-  OP_REPEAT_INC_NG,        /* non greedy */
-  OP_REPEAT_INC_SG,        /* search and get in stack */
-  OP_REPEAT_INC_NG_SG,     /* search and get in stack (non greedy) */
+  OP_REPEAT_INC_NG,         /* non greedy */
   OP_EMPTY_CHECK_START,     /* null loop checker start */
   OP_EMPTY_CHECK_END,       /* null loop checker end   */
   OP_EMPTY_CHECK_END_MEMST, /* null loop checker end (with capture status) */
+#ifdef USE_CALL
   OP_EMPTY_CHECK_END_MEMST_PUSH, /* with capture status and push check-end */
-
+#endif
   OP_PREC_READ_START,       /* (?=...)  start */
   OP_PREC_READ_END,         /* (?=...)  end   */
   OP_PREC_READ_NOT_START,   /* (?!...)  start */
@@ -589,11 +551,12 @@ enum OpCode {
   OP_LOOK_BEHIND,           /* (?<=...) start (no needs end opcode) */
   OP_LOOK_BEHIND_NOT_START, /* (?<!...) start */
   OP_LOOK_BEHIND_NOT_END,   /* (?<!...) end   */
-
-  OP_CALL,                  /* \g<name> */
-  OP_RETURN,
   OP_PUSH_SAVE_VAL,
   OP_UPDATE_VAR,
+#ifdef USE_CALL
+  OP_CALL,                  /* \g<name> */
+  OP_RETURN,
+#endif
 #ifdef USE_CALLOUT
   OP_CALLOUT_CONTENTS,      /* (?{...}) (?{{...}}) */
   OP_CALLOUT_NAME,          /* (*name) (*name[tag](args...)) */
@@ -601,8 +564,8 @@ enum OpCode {
 };
 
 enum SaveType {
-  SAVE_KEEP = 0, /* SAVE S */
-  SAVE_S = 1,
+  SAVE_KEEP        = 0, /* SAVE S */
+  SAVE_S           = 1,
   SAVE_RIGHT_RANGE = 2,
 };
 
@@ -642,116 +605,57 @@ typedef int ModeType;
 #define SIZE_UPDATE_VAR_TYPE  sizeof(UpdateVarType)
 #define SIZE_MODE             sizeof(ModeType)
 
-#define GET_RELADDR_INC(addr,p)    PLATFORM_GET_INC(addr,   p, RelAddrType)
-#define GET_ABSADDR_INC(addr,p)    PLATFORM_GET_INC(addr,   p, AbsAddrType)
-#define GET_LENGTH_INC(len,p)      PLATFORM_GET_INC(len,    p, LengthType)
-#define GET_MEMNUM_INC(num,p)      PLATFORM_GET_INC(num,    p, MemNumType)
-#define GET_REPEATNUM_INC(num,p)   PLATFORM_GET_INC(num,    p, RepeatNumType)
-#define GET_OPTION_INC(option,p)   PLATFORM_GET_INC(option, p, OnigOptionType)
-#define GET_POINTER_INC(ptr,p)     PLATFORM_GET_INC(ptr,    p, PointerType)
-#define GET_SAVE_TYPE_INC(type,p)       PLATFORM_GET_INC(type, p, SaveType)
-#define GET_UPDATE_VAR_TYPE_INC(type,p) PLATFORM_GET_INC(type, p, UpdateVarType)
-#define GET_MODE_INC(mode,p)            PLATFORM_GET_INC(mode, p, ModeType)
-
 /* code point's address must be aligned address. */
 #define GET_CODE_POINT(code,p)   code = *((OnigCodePoint* )(p))
-#define GET_BYTE_INC(byte,p) do{\
-  byte = *(p);\
-  (p)++;\
-} while(0)
 
 
 /* op-code + arg size */
-#if 0
-#define SIZE_OP_ANYCHAR_STAR            SIZE_OPCODE
-#define SIZE_OP_ANYCHAR_STAR_PEEK_NEXT (SIZE_OPCODE + 1)
-#define SIZE_OP_JUMP                   (SIZE_OPCODE + SIZE_RELADDR)
-#define SIZE_OP_PUSH                   (SIZE_OPCODE + SIZE_RELADDR)
-#define SIZE_OP_PUSH_SUPER             (SIZE_OPCODE + SIZE_RELADDR)
-#define SIZE_OP_POP_OUT                 SIZE_OPCODE
-#ifdef USE_OP_PUSH_OR_JUMP_EXACT
-#define SIZE_OP_PUSH_OR_JUMP_EXACT1    (SIZE_OPCODE + SIZE_RELADDR + 1)
-#endif
-#define SIZE_OP_PUSH_IF_PEEK_NEXT      (SIZE_OPCODE + SIZE_RELADDR + 1)
-#define SIZE_OP_REPEAT_INC             (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_REPEAT_INC_NG          (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_WORD_BOUNDARY          (SIZE_OPCODE + SIZE_MODE)
-#define SIZE_OP_PREC_READ_START         SIZE_OPCODE
-#define SIZE_OP_PREC_READ_NOT_START    (SIZE_OPCODE + SIZE_RELADDR)
-#define SIZE_OP_PREC_READ_END           SIZE_OPCODE
-#define SIZE_OP_PREC_READ_NOT_END       SIZE_OPCODE
-#define SIZE_OP_FAIL                    SIZE_OPCODE
-#define SIZE_OP_MEMORY_START           (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_MEMORY_START_PUSH      (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_MEMORY_END_PUSH        (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_MEMORY_END_PUSH_REC    (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_MEMORY_END             (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_MEMORY_END_REC         (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_ATOMIC_START            SIZE_OPCODE
-#define SIZE_OP_ATOMIC_END              SIZE_OPCODE
-#define SIZE_OP_EMPTY_CHECK_START       (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_EMPTY_CHECK_END         (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_LOOK_BEHIND            (SIZE_OPCODE + SIZE_LENGTH)
-#define SIZE_OP_LOOK_BEHIND_NOT_START  (SIZE_OPCODE + SIZE_RELADDR + SIZE_LENGTH)
-#define SIZE_OP_LOOK_BEHIND_NOT_END     SIZE_OPCODE
-#define SIZE_OP_CALL                   (SIZE_OPCODE + SIZE_ABSADDR)
-#define SIZE_OP_RETURN                  SIZE_OPCODE
-#define SIZE_OP_PUSH_SAVE_VAL          (SIZE_OPCODE + SIZE_SAVE_TYPE + SIZE_MEMNUM)
-#define SIZE_OP_UPDATE_VAR             (SIZE_OPCODE + SIZE_UPDATE_VAR_TYPE + SIZE_MEMNUM)
-
-#ifdef USE_CALLOUT
-#define SIZE_OP_CALLOUT_CONTENTS       (SIZE_OPCODE + SIZE_MEMNUM)
-#define SIZE_OP_CALLOUT_NAME           (SIZE_OPCODE + SIZE_MEMNUM + SIZE_MEMNUM)
-#endif
-
-#else  /* if 0 */
 
 /* for relative address increment to go next op. */
-#define SIZE_INC_OP                     1
-
-#define SIZE_OP_ANYCHAR_STAR            1
-#define SIZE_OP_ANYCHAR_STAR_PEEK_NEXT  1
-#define SIZE_OP_JUMP                    1
-#define SIZE_OP_PUSH                    1
-#define SIZE_OP_PUSH_SUPER              1
-#define SIZE_OP_POP_OUT                 1
+#define SIZE_INC                       1
+
+#define OPSIZE_ANYCHAR_STAR            1
+#define OPSIZE_ANYCHAR_STAR_PEEK_NEXT  1
+#define OPSIZE_JUMP                    1
+#define OPSIZE_PUSH                    1
+#define OPSIZE_PUSH_SUPER              1
+#define OPSIZE_POP_OUT                 1
 #ifdef USE_OP_PUSH_OR_JUMP_EXACT
-#define SIZE_OP_PUSH_OR_JUMP_EXACT1     1
-#endif
-#define SIZE_OP_PUSH_IF_PEEK_NEXT       1
-#define SIZE_OP_REPEAT                  1
-#define SIZE_OP_REPEAT_INC              1
-#define SIZE_OP_REPEAT_INC_NG           1
-#define SIZE_OP_WORD_BOUNDARY           1
-#define SIZE_OP_PREC_READ_START         1
-#define SIZE_OP_PREC_READ_NOT_START     1
-#define SIZE_OP_PREC_READ_END           1
-#define SIZE_OP_PREC_READ_NOT_END       1
-#define SIZE_OP_BACKREF                 1
-#define SIZE_OP_FAIL                    1
-#define SIZE_OP_MEMORY_START            1
-#define SIZE_OP_MEMORY_START_PUSH       1
-#define SIZE_OP_MEMORY_END_PUSH         1
-#define SIZE_OP_MEMORY_END_PUSH_REC     1
-#define SIZE_OP_MEMORY_END              1
-#define SIZE_OP_MEMORY_END_REC          1
-#define SIZE_OP_ATOMIC_START            1
-#define SIZE_OP_ATOMIC_END              1
-#define SIZE_OP_EMPTY_CHECK_START       1
-#define SIZE_OP_EMPTY_CHECK_END         1
-#define SIZE_OP_LOOK_BEHIND             1
-#define SIZE_OP_LOOK_BEHIND_NOT_START   1
-#define SIZE_OP_LOOK_BEHIND_NOT_END     1
-#define SIZE_OP_CALL                    1
-#define SIZE_OP_RETURN                  1
-#define SIZE_OP_PUSH_SAVE_VAL           1
-#define SIZE_OP_UPDATE_VAR              1
+#define OPSIZE_PUSH_OR_JUMP_EXACT1     1
+#endif
+#define OPSIZE_PUSH_IF_PEEK_NEXT       1
+#define OPSIZE_REPEAT                  1
+#define OPSIZE_REPEAT_INC              1
+#define OPSIZE_REPEAT_INC_NG           1
+#define OPSIZE_WORD_BOUNDARY           1
+#define OPSIZE_PREC_READ_START         1
+#define OPSIZE_PREC_READ_NOT_START     1
+#define OPSIZE_PREC_READ_END           1
+#define OPSIZE_PREC_READ_NOT_END       1
+#define OPSIZE_BACKREF                 1
+#define OPSIZE_FAIL                    1
+#define OPSIZE_MEM_START               1
+#define OPSIZE_MEM_START_PUSH          1
+#define OPSIZE_MEM_END_PUSH            1
+#define OPSIZE_MEM_END_PUSH_REC        1
+#define OPSIZE_MEM_END                 1
+#define OPSIZE_MEM_END_REC             1
+#define OPSIZE_ATOMIC_START            1
+#define OPSIZE_ATOMIC_END              1
+#define OPSIZE_EMPTY_CHECK_START       1
+#define OPSIZE_EMPTY_CHECK_END         1
+#define OPSIZE_LOOK_BEHIND             1
+#define OPSIZE_LOOK_BEHIND_NOT_START   1
+#define OPSIZE_LOOK_BEHIND_NOT_END     1
+#define OPSIZE_CALL                    1
+#define OPSIZE_RETURN                  1
+#define OPSIZE_PUSH_SAVE_VAL           1
+#define OPSIZE_UPDATE_VAR              1
 
 #ifdef USE_CALLOUT
-#define SIZE_OP_CALLOUT_CONTENTS        1
-#define SIZE_OP_CALLOUT_NAME            1
+#define OPSIZE_CALLOUT_CONTENTS        1
+#define OPSIZE_CALLOUT_NAME            1
 #endif
-#endif /* if 0 */
 
 
 #define MC_ESC(syn)               (syn)->meta_char_table.esc
@@ -882,7 +786,7 @@ typedef struct {
     } repeat; /* REPEAT, REPEAT_NG */
     struct {
       MemNumType  id;
-    } repeat_inc; /* REPEAT_INC, REPEAT_INC_SG, REPEAT_INC_NG, REPEAT_INC_NG_SG */
+    } repeat_inc; /* REPEAT_INC, REPEAT_INC_NG */
     struct {
       MemNumType mem;
     } empty_check_start;
@@ -933,48 +837,58 @@ typedef struct {
 #endif
 } RegexExt;
 
+typedef struct {
+  int lower;
+  int upper;
+  union {
+    Operation* pcode; /* address of repeated body */
+    int offset;
+  } u;
+} RepeatRange;
+
 struct re_pattern_buffer {
   /* common members of BBuf(bytes-buffer) */
   Operation*   ops;
 #ifdef USE_DIRECT_THREADED_CODE
   enum OpCode* ocs;
 #endif
-  Operation*   ops_curr;
-  unsigned int ops_used;    /* used space for ops */
-  unsigned int ops_alloc;   /* allocated space for ops */
+  Operation*     ops_curr;
+  unsigned int   ops_used;    /* used space for ops */
+  unsigned int   ops_alloc;   /* allocated space for ops */
   unsigned char* string_pool;
   unsigned char* string_pool_end;
 
-  int num_mem;                   /* used memory(...) num counted from 1 */
-  int num_repeat;                /* OP_REPEAT/OP_REPEAT_NG id-counter */
-  int num_null_check;            /* OP_EMPTY_CHECK_START/END id counter */
-  int num_call;                  /* number of subexp call */
-  unsigned int capture_history;  /* (?@...) flag (1-31) */
-  unsigned int bt_mem_start;     /* need backtrack flag */
-  unsigned int bt_mem_end;       /* need backtrack flag */
-  int stack_pop_level;
-  int repeat_range_alloc;
-  OnigRepeatRange* repeat_range;
-
-  OnigEncoding      enc;
-  OnigOptionType    options;
-  OnigSyntaxType*   syntax;
-  OnigCaseFoldType  case_fold_flag;
-  void*             name_table;
+  int            num_mem;          /* used memory(...) num counted from 1 */
+  int            num_repeat;       /* OP_REPEAT/OP_REPEAT_NG id-counter */
+  int            num_empty_check;  /* OP_EMPTY_CHECK_START/END id counter */
+  int            num_call;         /* number of subexp call */
+  MemStatusType  capture_history;  /* (?@...) flag (1-31) */
+  MemStatusType  push_mem_start;   /* need backtrack flag */
+  MemStatusType  push_mem_end;     /* need backtrack flag */
+  MemStatusType  empty_status_mem;
+  int            stack_pop_level;
+  int            repeat_range_alloc;
+  RepeatRange*   repeat_range;
+
+  OnigEncoding     enc;
+  OnigOptionType   options;
+  OnigSyntaxType*  syntax;
+  OnigCaseFoldType case_fold_flag;
+  void*            name_table;
 
   /* optimization info (string search, char-map and anchors) */
   int            optimize;          /* optimize flag */
   int            threshold_len;     /* search str-length for apply optimize */
   int            anchor;            /* BEGIN_BUF, BEGIN_POS, (SEMI_)END_BUF */
-  OnigLen        anchor_dmin;       /* (SEMI_)END_BUF anchor distance */
-  OnigLen        anchor_dmax;       /* (SEMI_)END_BUF anchor distance */
+  OnigLen        anc_dist_min;      /* (SEMI_)END_BUF anchor distance */
+  OnigLen        anc_dist_max;      /* (SEMI_)END_BUF anchor distance */
   int            sub_anchor;        /* start-anchor for exact or map */
   unsigned char *exact;
   unsigned char *exact_end;
   unsigned char  map[CHAR_MAP_SIZE]; /* used as BMH skip or char-map */
   int            map_offset;
-  OnigLen        dmin;                      /* min-distance of exact or map */
-  OnigLen        dmax;                      /* max-distance of exact or map */
+  OnigLen        dist_min;           /* min-distance of exact or map */
+  OnigLen        dist_max;           /* max-distance of exact or map */
   RegexExt*      extp;
 };
 
diff --git a/src/regparse.c b/src/regparse.c
index 7f8b1a9..fed53f7 100644
--- a/src/regparse.c
+++ b/src/regparse.c
@@ -2,7 +2,7 @@
   regparse.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -199,6 +199,24 @@ onig_set_parse_depth_limit(unsigned int depth)
   return 0;
 }
 
+#ifdef ONIG_DEBUG_PARSE
+#define INC_PARSE_DEPTH(d) do {\
+  (d)++;\
+  if (env->max_parse_depth < (d)) env->max_parse_depth = d;\
+  if ((d) > ParseDepthLimit) \
+    return ONIGERR_PARSE_DEPTH_LIMIT_OVER;\
+} while (0)
+#else
+#define INC_PARSE_DEPTH(d) do {\
+  (d)++;\
+  if ((d) > ParseDepthLimit) \
+    return ONIGERR_PARSE_DEPTH_LIMIT_OVER;\
+} while (0)
+#endif
+
+#define DEC_PARSE_DEPTH(d)  (d)--
+
+
 static int
 bbuf_init(BBuf* buf, int size)
 {
@@ -244,7 +262,8 @@ bbuf_clone(BBuf** rto, BBuf* from)
   return 0;
 }
 
-static int backref_rel_to_abs(int rel_no, ScanEnv* env)
+static int
+backref_rel_to_abs(int rel_no, ScanEnv* env)
 {
   if (rel_no > 0) {
     return env->num_mem + rel_no;
@@ -292,15 +311,6 @@ bitset_set_range(BitSetRef bs, int from, int to)
   }
 }
 
-#if 0
-static void
-bitset_set_all(BitSetRef bs)
-{
-  int i;
-  for (i = 0; i < BITSET_SIZE; i++) { bs[i] = ~((Bits )0); }
-}
-#endif
-
 static void
 bitset_invert(BitSetRef bs)
 {
@@ -363,24 +373,6 @@ save_entry(ScanEnv* env, enum SaveType type, int* id)
 {
   int nid = env->save_num;
 
-#if 0
-  if (IS_NULL(env->saves)) {
-    int n = 10;
-    env->saves = (SaveItem* )xmalloc(sizeof(SaveItem) * n);
-    CHECK_NULL_RETURN_MEMERR(env->saves);
-    env->save_alloc_num = n;
-  }
-  else if (env->save_alloc_num <= nid) {
-    int n = env->save_alloc_num * 2;
-    SaveItem* p = (SaveItem* )xrealloc(env->saves, sizeof(SaveItem) * n);
-    CHECK_NULL_RETURN_MEMERR(p);
-    env->saves = p;
-    env->save_alloc_num = n;
-  }
-
-  env->saves[nid].type = type;
-#endif
-
   env->save_num++;
   *id = nid;
   return 0;
@@ -476,14 +468,14 @@ static int
 str_end_hash(st_str_end_key* x)
 {
   UChar *p;
-  int val = 0;
+  unsigned val = 0;
 
   p = x->s;
   while (p < x->end) {
-    val = val * 997 + (int )*p++;
+    val = val * 997 + (unsigned )*p++;
   }
 
-  return val + (val >> 5);
+  return (int) (val + (val >> 5));
 }
 
 extern hash_table_type*
@@ -566,15 +558,15 @@ static int
 callout_name_table_hash(st_callout_name_key* x)
 {
   UChar *p;
-  int val = 0;
+  unsigned int val = 0;
 
   p = x->s;
   while (p < x->end) {
-    val = val * 997 + (int )*p++;
+    val = val * 997 + (unsigned int )*p++;
   }
 
   /* use intptr_t for escape warning in Windows */
-  return val + (val >> 5) + ((intptr_t )x->enc & 0xffff) + x->type;
+  return (int )(val + (val >> 5) + ((intptr_t )x->enc & 0xffff) + x->type);
 }
 
 extern hash_table_type*
@@ -1972,9 +1964,8 @@ callout_tag_entry(ScanEnv* env, regex_t* reg, UChar* name, UChar* name_end,
 static void
 scan_env_clear(ScanEnv* env)
 {
-  MEM_STATUS_CLEAR(env->capture_history);
-  MEM_STATUS_CLEAR(env->bt_mem_start);
-  MEM_STATUS_CLEAR(env->bt_mem_end);
+  MEM_STATUS_CLEAR(env->cap_history);
+  MEM_STATUS_CLEAR(env->backtrack_mem);
   MEM_STATUS_CLEAR(env->backrefed_mem);
   env->error      = (UChar* )NULL;
   env->error_end  = (UChar* )NULL;
@@ -1993,6 +1984,10 @@ scan_env_clear(ScanEnv* env)
   xmemset(env->mem_env_static, 0, sizeof(env->mem_env_static));
 
   env->parse_depth         = 0;
+#ifdef ONIG_DEBUG_PARSE
+  env->max_parse_depth     = 0;
+#endif
+  env->backref_num         = 0;
   env->keep_num            = 0;
   env->save_num            = 0;
   env->save_alloc_num      = 0;
@@ -2024,11 +2019,8 @@ scan_env_add_mem_entry(ScanEnv* env)
       }
 
       for (i = env->num_mem + 1; i < alloc; i++) {
-        p[i].node = NULL_NODE;
-#if 0
-        p[i].in   = 0;
-        p[i].recursion = 0;
-#endif
+        p[i].mem_node = NULL_NODE;
+        p[i].empty_repeat_node = NULL_NODE;
       }
 
       env->mem_env_dynamic = p;
@@ -2044,7 +2036,7 @@ static int
 scan_env_set_mem_node(ScanEnv* env, int num, Node* node)
 {
   if (env->num_mem >= num)
-    SCANENV_MEMENV(env)[num].node = node;
+    SCANENV_MEMENV(env)[num].mem_node = node;
   else
     return ONIGERR_PARSER_BUG;
   return 0;
@@ -2182,7 +2174,7 @@ node_new_ctype(int type, int not, OnigOptionType options)
 static Node*
 node_new_anychar(void)
 {
-  Node* node = node_new_ctype(CTYPE_ANYCHAR, 0, ONIG_OPTION_NONE);
+  Node* node = node_new_ctype(CTYPE_ANYCHAR, FALSE, ONIG_OPTION_NONE);
   return node;
 }
 
@@ -2242,24 +2234,6 @@ onig_node_new_list(Node* left, Node* right)
 }
 
 extern Node*
-onig_node_list_add(Node* list, Node* x)
-{
-  Node *n;
-
-  n = onig_node_new_list(x, NULL);
-  if (IS_NULL(n)) return NULL_NODE;
-
-  if (IS_NOT_NULL(list)) {
-    while (IS_NOT_NULL(NODE_CDR(list)))
-      list = NODE_CDR(list);
-
-    NODE_CDR(list) = n;
-  }
-
-  return n;
-}
-
-extern Node*
 onig_node_new_alt(Node* left, Node* right)
 {
   Node* node = node_new();
@@ -2357,7 +2331,7 @@ node_new_backref(int back_num, int* backrefs, int by_name,
 
   for (i = 0; i < back_num; i++) {
     if (backrefs[i] <= env->num_mem &&
-        IS_NULL(SCANENV_MEMENV(env)[backrefs[i]].node)) {
+        IS_NULL(SCANENV_MEMENV(env)[backrefs[i]].mem_node)) {
       NODE_STATUS_ADD(node, RECURSION);   /* /...(\1).../ */
       break;
     }
@@ -2377,6 +2351,8 @@ node_new_backref(int back_num, int* backrefs, int by_name,
     for (i = 0; i < back_num; i++)
       p[i] = backrefs[i];
   }
+
+  env->backref_num++;
   return node;
 }
 
@@ -2424,13 +2400,13 @@ node_new_quantifier(int lower, int upper, int by_number)
   CHECK_NULL_RETURN(node);
 
   NODE_SET_TYPE(node, NODE_QUANT);
-  QUANT_(node)->lower           = lower;
-  QUANT_(node)->upper           = upper;
-  QUANT_(node)->greedy          = 1;
-  QUANT_(node)->emptiness       = BODY_IS_NOT_EMPTY;
-  QUANT_(node)->head_exact      = NULL_NODE;
-  QUANT_(node)->next_head_exact = NULL_NODE;
-  QUANT_(node)->is_refered      = 0;
+  QUANT_(node)->lower            = lower;
+  QUANT_(node)->upper            = upper;
+  QUANT_(node)->greedy           = 1;
+  QUANT_(node)->emptiness        = BODY_IS_NOT_EMPTY;
+  QUANT_(node)->head_exact       = NULL_NODE;
+  QUANT_(node)->next_head_exact  = NULL_NODE;
+  QUANT_(node)->include_referred = 0;
   if (by_number != 0)
     NODE_STATUS_ADD(node, BY_NUMBER);
 
@@ -2716,7 +2692,7 @@ make_text_segment(Node** node, ScanEnv* env)
   ns[1] = NULL_NODE;
 
   r = ONIGERR_MEMORY;
-  ns[0] = onig_node_new_anchor(ANCR_NO_TEXT_SEGMENT_BOUNDARY, 0);
+  ns[0] = onig_node_new_anchor(ANCR_NO_TEXT_SEGMENT_BOUNDARY, FALSE);
   if (IS_NULL(ns[0])) goto err;
 
   r = node_new_true_anychar(&ns[1], env);
@@ -2727,7 +2703,7 @@ make_text_segment(Node** node, ScanEnv* env)
   ns[0] = x;
   ns[1] = NULL_NODE;
 
-  x = node_new_quantifier(0, INFINITE_REPEAT, 1);
+  x = node_new_quantifier(0, INFINITE_REPEAT, TRUE);
   if (IS_NULL(x)) goto err;
 
   NODE_BODY(x) = ns[0];
@@ -2796,7 +2772,7 @@ make_absent_engine(Node** node, int pre_save_right_id, Node* absent,
 
   ns[0] = x;
 
-  x = node_new_quantifier(lower, upper, 0);
+  x = node_new_quantifier(lower, upper, FALSE);
   if (IS_NULL(x)) goto err0;
 
   NODE_BODY(x) = ns[0];
@@ -2825,7 +2801,7 @@ make_absent_engine(Node** node, int pre_save_right_id, Node* absent,
   x = make_alt(2, ns);
   if (IS_NULL(x)) goto err0;
 
-  if (is_range_cutter != 0)
+  if (is_range_cutter != FALSE)
     NODE_STATUS_ADD(x, SUPER);
 
   *node = x;
@@ -2915,7 +2891,10 @@ make_range_clear(Node** node, ScanEnv* env)
 
   ns[0] = NULL_NODE; ns[1] = x;
 
-  r = node_new_update_var_gimmick(&ns[0], UPDATE_VAR_RIGHT_RANGE_INIT, 0, env);
+#define ID_NOT_USED_DONT_CARE_ME   0
+
+  r = node_new_update_var_gimmick(&ns[0], UPDATE_VAR_RIGHT_RANGE_INIT,
+                                  ID_NOT_USED_DONT_CARE_ME, env);
   if (r != 0) goto err;
 
   x = make_alt(2, ns);
@@ -3034,7 +3013,7 @@ make_absent_tree_for_simple_one_char_repeat(Node** node, Node* absent, Node* qua
   id1 = GIMMICK_(ns[0])->id;
 
   r = make_absent_engine(&ns[1], id1, absent, body, lower, upper, possessive,
-                         0, env);
+                         FALSE, env);
   if (r != 0) goto err;
 
   ns[2] = ns[3] = NULL_NODE;
@@ -3077,7 +3056,7 @@ make_absent_tree(Node** node, Node* absent, Node* expr, int is_range_cutter,
 
     if (expr == NULL_NODE) {
       /* default expr \O* */
-      quant = node_new_quantifier(0, INFINITE_REPEAT, 0);
+      quant = node_new_quantifier(0, INFINITE_REPEAT, FALSE);
       if (IS_NULL(quant)) goto err0;
 
       r = node_new_true_anychar(&body, env);
@@ -3204,16 +3183,6 @@ node_str_cat_char(Node* node, UChar c)
 }
 
 extern void
-onig_node_conv_to_str_node(Node* node, int flag)
-{
-  NODE_SET_TYPE(node, NODE_STRING);
-  STR_(node)->flag     = flag;
-  STR_(node)->capacity = 0;
-  STR_(node)->s        = STR_(node)->buf;
-  STR_(node)->end      = STR_(node)->buf;
-}
-
-extern void
 onig_node_str_clear(Node* node)
 {
   if (STR_(node)->capacity != 0 &&
@@ -3221,10 +3190,11 @@ onig_node_str_clear(Node* node)
     xfree(STR_(node)->s);
   }
 
-  STR_(node)->capacity = 0;
   STR_(node)->flag     = 0;
   STR_(node)->s        = STR_(node)->buf;
   STR_(node)->end      = STR_(node)->buf;
+  STR_(node)->capacity = 0;
+  STR_(node)->case_min_len = 0;
 }
 
 static Node*
@@ -3234,10 +3204,12 @@ node_new_str(const UChar* s, const UChar* end)
   CHECK_NULL_RETURN(node);
 
   NODE_SET_TYPE(node, NODE_STRING);
-  STR_(node)->capacity = 0;
   STR_(node)->flag     = 0;
   STR_(node)->s        = STR_(node)->buf;
   STR_(node)->end      = STR_(node)->buf;
+  STR_(node)->capacity = 0;
+  STR_(node)->case_min_len = 0;
+
   if (onig_node_str_cat(node, s, end)) {
     onig_node_free(node);
     return NULL;
@@ -3252,11 +3224,11 @@ onig_node_new_str(const UChar* s, const UChar* end)
 }
 
 static Node*
-node_new_str_raw(UChar* s, UChar* end)
+node_new_str_crude(UChar* s, UChar* end)
 {
   Node* node = node_new_str(s, end);
   CHECK_NULL_RETURN(node);
-  NODE_STRING_SET_RAW(node);
+  NODE_STRING_SET_CRUDE(node);
   return node;
 }
 
@@ -3267,14 +3239,14 @@ node_new_empty(void)
 }
 
 static Node*
-node_new_str_raw_char(UChar c)
+node_new_str_crude_char(UChar c)
 {
   int i;
   UChar p[1];
   Node* node;
 
   p[0] = c;
-  node = node_new_str_raw(p, p + 1);
+  node = node_new_str_crude(p, p + 1);
 
   /* clear buf tail */
   for (i = 1; i < NODE_STRING_BUF_SIZE; i++)
@@ -3297,8 +3269,8 @@ str_node_split_last_char(Node* node, OnigEncoding enc)
     if (p && p > sn->s) { /* can be split. */
       rn = node_new_str(p, sn->end);
       CHECK_NULL_RETURN(rn);
-      if (NODE_STRING_IS_RAW(node))
-        NODE_STRING_SET_RAW(rn);
+      if (NODE_STRING_IS_CRUDE(node))
+        NODE_STRING_SET_CRUDE(rn);
 
       sn->end = (UChar* )p;
     }
@@ -3316,10 +3288,10 @@ str_node_can_be_split(Node* node, OnigEncoding enc)
   return 0;
 }
 
-extern int
-onig_scan_unsigned_number(UChar** src, const UChar* end, OnigEncoding enc)
+static int
+scan_number(UChar** src, const UChar* end, OnigEncoding enc)
 {
-  unsigned int num, val;
+  int num, val;
   OnigCodePoint c;
   UChar* p = *src;
   PFETCH_READY;
@@ -3328,8 +3300,8 @@ onig_scan_unsigned_number(UChar** src, const UChar* end, OnigEncoding enc)
   while (! PEND) {
     PFETCH(c);
     if (IS_CODE_DIGIT_ASCII(enc, c)) {
-      val = (unsigned int )DIGITVAL(c);
-      if ((INT_MAX_LIMIT - val) / 10UL < num)
+      val = (int )DIGITVAL(c);
+      if ((INT_MAX - val) / 10 < num)
         return -1;  /* overflow */
 
       num = num * 10 + val;
@@ -3344,26 +3316,27 @@ onig_scan_unsigned_number(UChar** src, const UChar* end, OnigEncoding enc)
 }
 
 static int
-scan_unsigned_hexadecimal_number(UChar** src, UChar* end, int minlen,
-                                 int maxlen, OnigEncoding enc)
+scan_hexadecimal_number(UChar** src, UChar* end, int minlen, int maxlen,
+                        OnigEncoding enc, OnigCodePoint* rcode)
 {
+  OnigCodePoint code;
   OnigCodePoint c;
-  unsigned int num, val;
+  unsigned int val;
   int n;
   UChar* p = *src;
   PFETCH_READY;
 
-  num = 0;
+  code = 0;
   n = 0;
   while (! PEND && n < maxlen) {
     PFETCH(c);
     if (IS_CODE_XDIGIT_ASCII(enc, c)) {
       n++;
-      val = (unsigned int )XDIGITVAL(enc,c);
-      if ((INT_MAX_LIMIT - val) / 16UL < num)
+      val = (unsigned int )XDIGITVAL(enc, c);
+      if ((UINT_MAX - val) / 16UL < code)
         return ONIGERR_TOO_BIG_NUMBER; /* overflow */
 
-      num = (num << 4) + XDIGITVAL(enc,c);
+      code = (code << 4) + val;
     }
     else {
       PUNFETCH;
@@ -3374,36 +3347,46 @@ scan_unsigned_hexadecimal_number(UChar** src, UChar* end, int minlen,
   if (n < minlen)
     return ONIGERR_INVALID_CODE_POINT_VALUE;
 
+  *rcode = code;
   *src = p;
-  return num;
+  return ONIG_NORMAL;
 }
 
 static int
-scan_unsigned_octal_number(UChar** src, UChar* end, int maxlen,
-                           OnigEncoding enc)
+scan_octal_number(UChar** src, UChar* end, int minlen, int maxlen,
+                  OnigEncoding enc, OnigCodePoint* rcode)
 {
+  OnigCodePoint code;
   OnigCodePoint c;
-  unsigned int num, val;
+  unsigned int val;
+  int n;
   UChar* p = *src;
   PFETCH_READY;
 
-  num = 0;
-  while (! PEND && maxlen-- != 0) {
+  code = 0;
+  n = 0;
+  while (! PEND && n < maxlen) {
     PFETCH(c);
     if (IS_CODE_DIGIT_ASCII(enc, c) && c < '8') {
-      val = ODIGITVAL(c);
-      if ((INT_MAX_LIMIT - val) / 8UL < num)
-        return -1;  /* overflow */
+      n++;
+      val = (unsigned int )ODIGITVAL(c);
+      if ((UINT_MAX - val) / 8UL < code)
+        return ONIGERR_TOO_BIG_NUMBER; /* overflow */
 
-      num = (num << 3) + val;
+      code = (code << 3) + val;
     }
     else {
       PUNFETCH;
       break;
     }
   }
+
+  if (n < minlen)
+    return ONIGERR_INVALID_CODE_POINT_VALUE;
+
+  *rcode = code;
   *src = p;
-  return num;
+  return ONIG_NORMAL;
 }
 
 
@@ -3938,68 +3921,70 @@ static enum ReduceType ReduceTypeTable[6][6] = {
   {RQ_ASIS, RQ_PQ_Q, RQ_DEL, RQ_AQ,   RQ_AQ,   RQ_DEL}   /* '+?' */
 };
 
-extern void
-onig_reduce_nested_quantifier(Node* pnode, Node* cnode)
+extern int
+onig_reduce_nested_quantifier(Node* pnode)
 {
   int pnum, cnum;
   QuantNode *p, *c;
+  Node* cnode;
+
+  cnode = NODE_BODY(pnode);
 
   p = QUANT_(pnode);
   c = QUANT_(cnode);
   pnum = quantifier_type_num(p);
   cnum = quantifier_type_num(c);
   if (pnum < 0 || cnum < 0) {
-    if ((p->lower == p->upper) && ! IS_INFINITE_REPEAT(p->upper)) {
-      if ((c->lower == c->upper) && ! IS_INFINITE_REPEAT(c->upper)) {
-        int n = onig_positive_int_multiply(p->lower, c->lower);
-        if (n >= 0) {
-          p->lower = p->upper = n;
-          NODE_BODY(pnode) = NODE_BODY(cnode);
-          goto remove_cnode;
-        }
-      }
+    if (p->lower == p->upper && c->lower == c->upper) {
+      int n = onig_positive_int_multiply(p->lower, c->lower);
+      if (n < 0) return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
+
+      p->lower = p->upper = n;
+      NODE_BODY(pnode) = NODE_BODY(cnode);
+      goto remove_cnode;
     }
 
-    return ;
+    return 0;
   }
 
   switch(ReduceTypeTable[cnum][pnum]) {
   case RQ_DEL:
     *pnode = *cnode;
+    goto remove_cnode;
     break;
   case RQ_A:
     NODE_BODY(pnode) = NODE_BODY(cnode);
     p->lower  = 0;  p->upper = INFINITE_REPEAT;  p->greedy = 1;
+    goto remove_cnode;
     break;
   case RQ_AQ:
     NODE_BODY(pnode) = NODE_BODY(cnode);
     p->lower  = 0;  p->upper = INFINITE_REPEAT;  p->greedy = 0;
+    goto remove_cnode;
     break;
   case RQ_QQ:
     NODE_BODY(pnode) = NODE_BODY(cnode);
     p->lower  = 0;  p->upper = 1;  p->greedy = 0;
+    goto remove_cnode;
     break;
   case RQ_P_QQ:
-    NODE_BODY(pnode) = cnode;
     p->lower  = 0;  p->upper = 1;  p->greedy = 0;
     c->lower  = 1;  c->upper = INFINITE_REPEAT;  c->greedy = 1;
-    return ;
     break;
   case RQ_PQ_Q:
-    NODE_BODY(pnode) = cnode;
     p->lower  = 0;  p->upper = 1;  p->greedy = 1;
     c->lower  = 1;  c->upper = INFINITE_REPEAT;  c->greedy = 0;
-    return ;
     break;
   case RQ_ASIS:
-    NODE_BODY(pnode) = cnode;
-    return ;
     break;
   }
 
+  return 0;
+
  remove_cnode:
   NODE_BODY(cnode) = NULL_NODE;
   onig_node_free(cnode);
+  return 0;
 }
 
 static int
@@ -4018,7 +4003,7 @@ node_new_general_newline(Node** node, ScanEnv* env)
   alen = ONIGENC_CODE_TO_MBC(env->enc, 0x0a, buf + dlen);
   if (alen < 0) return alen;
 
-  crnl = node_new_str_raw(buf, buf + dlen + alen);
+  crnl = node_new_str_crude(buf, buf + dlen + alen);
   CHECK_NULL_RETURN_MEMERR(crnl);
 
   ncc = node_new_cclass();
@@ -4046,7 +4031,7 @@ node_new_general_newline(Node** node, ScanEnv* env)
     if (r != 0) goto err1;
   }
 
-  x = node_new_bag_if_else(crnl, 0, ncc);
+  x = node_new_bag_if_else(crnl, NULL_NODE, ncc);
   if (IS_NULL(x)) goto err1;
 
   *node = x;
@@ -4055,7 +4040,7 @@ node_new_general_newline(Node** node, ScanEnv* env)
 
 enum TokenSyms {
   TK_EOT      = 0,   /* end of token */
-  TK_RAW_BYTE = 1,
+  TK_CRUDE_BYTE = 1,
   TK_CHAR,
   TK_STRING,
   TK_CODE_POINT,
@@ -4070,7 +4055,7 @@ enum TokenSyms {
   TK_ALT,
   TK_SUBEXP_OPEN,
   TK_SUBEXP_CLOSE,
-  TK_CC_OPEN,
+  TK_OPEN_CC,
   TK_QUOTE_OPEN,
   TK_CHAR_PROPERTY,    /* \p{...}, \P{...} */
   TK_KEEP,             /* \K */
@@ -4082,9 +4067,9 @@ enum TokenSyms {
   /* in cc */
   TK_CC_CLOSE,
   TK_CC_RANGE,
-  TK_POSIX_BRACKET_OPEN,
-  TK_CC_AND,             /* && */
-  TK_CC_CC_OPEN          /* [ */
+  TK_CC_POSIX_BRACKET_OPEN,
+  TK_CC_AND,           /* && */
+  TK_CC_OPEN_CC        /* [ */
 };
 
 typedef struct {
@@ -4094,7 +4079,7 @@ typedef struct {
   UChar* backp;
   union {
     UChar* s;
-    int   c;
+    UChar byte;
     OnigCodePoint code;
     int   anchor;
     int   subtype;
@@ -4129,7 +4114,7 @@ typedef struct {
 
 
 static int
-fetch_interval_quantifier(UChar** src, UChar* end, PToken* tok, ScanEnv* env)
+fetch_interval(UChar** src, UChar* end, PToken* tok, ScanEnv* env)
 {
   int low, up, syn_allow, non_low = 0;
   int r = 0;
@@ -4154,7 +4139,7 @@ fetch_interval_quantifier(UChar** src, UChar* end, PToken* tok, ScanEnv* env)
     }
   }
 
-  low = onig_scan_unsigned_number(&p, end, env->enc);
+  low = scan_number(&p, end, env->enc);
   if (low < 0) return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
   if (low > ONIG_MAX_REPEAT_NUM)
     return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
@@ -4173,7 +4158,7 @@ fetch_interval_quantifier(UChar** src, UChar* end, PToken* tok, ScanEnv* env)
   PFETCH(c);
   if (c == ',') {
     UChar* prev = p;
-    up = onig_scan_unsigned_number(&p, end, env->enc);
+    up = scan_number(&p, end, env->enc);
     if (up < 0) return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
     if (up > ONIG_MAX_REPEAT_NUM)
       return ONIGERR_TOO_BIG_NUMBER_FOR_REPEAT_RANGE;
@@ -4196,7 +4181,7 @@ fetch_interval_quantifier(UChar** src, UChar* end, PToken* tok, ScanEnv* env)
   if (PEND) goto invalid;
   PFETCH(c);
   if (IS_SYNTAX_OP(env->syntax, ONIG_SYN_OP_ESC_BRACE_INTERVAL)) {
-    if (c != MC_ESC(env->syntax)) goto invalid;
+    if (c != MC_ESC(env->syntax) || PEND) goto invalid;
     PFETCH(c);
   }
   if (c != '}') goto invalid;
@@ -4419,7 +4404,7 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
       PFETCH(c);
       if (! IS_CODE_DIGIT_ASCII(enc, c)) goto err;
       PUNFETCH;
-      level = onig_scan_unsigned_number(&p, end, enc);
+      level = scan_number(&p, end, enc);
       if (level < 0) return ONIGERR_TOO_BIG_NUMBER;
       *rlevel = (level * flag);
       exist_level = 1;
@@ -4440,7 +4425,7 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
  end:
   if (r == 0) {
     if (*num_type != IS_NOT_NUM) {
-      *rback_num = onig_scan_unsigned_number(&pnum_head, name_end, enc);
+      *rback_num = scan_number(&pnum_head, name_end, enc);
       if (*rback_num < 0) return ONIGERR_TOO_BIG_NUMBER;
       else if (*rback_num == 0) {
         if (*num_type == IS_REL_NUM)
@@ -4468,7 +4453,7 @@ fetch_name_with_level(OnigCodePoint start_code, UChar** src, UChar* end,
 static int
 fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
            UChar** rname_end, ScanEnv* env, int* rback_num,
-           enum REF_NUM* num_type, int ref)
+           enum REF_NUM* num_type, int is_ref)
 {
   int r, sign;
   int digit_count;
@@ -4498,7 +4483,7 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
       return ONIGERR_EMPTY_GROUP_NAME;
 
     if (IS_CODE_DIGIT_ASCII(enc, c)) {
-      if (ref == 1)
+      if (is_ref == TRUE)
         *num_type = IS_ABS_NUM;
       else {
         r = ONIGERR_INVALID_GROUP_NAME;
@@ -4506,7 +4491,7 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
       digit_count++;
     }
     else if (c == '-') {
-      if (ref == 1) {
+      if (is_ref == TRUE) {
         *num_type = IS_REL_NUM;
         sign = -1;
         pnum_head = p;
@@ -4516,7 +4501,7 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
       }
     }
     else if (c == '+') {
-      if (ref == 1) {
+      if (is_ref == TRUE) {
         *num_type = IS_REL_NUM;
         sign = 1;
         pnum_head = p;
@@ -4566,7 +4551,7 @@ fetch_name(OnigCodePoint start_code, UChar** src, UChar* end,
     }
 
     if (*num_type != IS_NOT_NUM) {
-      *rback_num = onig_scan_unsigned_number(&pnum_head, name_end, enc);
+      *rback_num = scan_number(&pnum_head, name_end, enc);
       if (*rback_num < 0) return ONIGERR_TOO_BIG_NUMBER;
       else if (*rback_num == 0) {
         if (*num_type == IS_REL_NUM) {
@@ -4698,7 +4683,8 @@ str_exist_check_with_esc(OnigCodePoint s[], int n, UChar* from, UChar* to,
 static int
 fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 {
-  int num;
+  int r;
+  OnigCodePoint code;
   OnigCodePoint c, c2;
   OnigSyntaxType* syn = env->syntax;
   OnigEncoding enc = env->enc;
@@ -4714,7 +4700,7 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
   PFETCH(c);
   tok->type = TK_CHAR;
   tok->base = 0;
-  tok->u.c  = c;
+  tok->u.code = c;
   tok->escaped = 0;
 
   if (c == ']') {
@@ -4731,7 +4717,7 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
     PFETCH(c);
     tok->escaped = 1;
-    tok->u.c = c;
+    tok->u.code = c;
     switch (c) {
     case 'w':
       tok->type = TK_CHAR_TYPE;
@@ -4804,8 +4790,8 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       prev = p;
       if (PPEEK_IS('{') && IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_O_BRACE_OCTAL)) {
         PINC;
-        num = scan_unsigned_octal_number(&p, end, 11, enc);
-        if (num < 0) return ONIGERR_TOO_BIG_WIDE_CHAR_VALUE;
+        r = scan_octal_number(&p, end, 0, 11, enc, &code);
+        if (r < 0) return r;
         if (!PEND) {
           c2 = PPEEK;
           if (IS_CODE_DIGIT_ASCII(enc, c2))
@@ -4816,7 +4802,7 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
           PINC;
           tok->type   = TK_CODE_POINT;
           tok->base   = 8;
-          tok->u.code = (OnigCodePoint )num;
+          tok->u.code = code;
         }
         else {
           /* can't read nothing or invalid format */
@@ -4831,13 +4817,8 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       prev = p;
       if (PPEEK_IS('{') && IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_X_BRACE_HEX8)) {
         PINC;
-        num = scan_unsigned_hexadecimal_number(&p, end, 0, 8, enc);
-        if (num < 0) {
-          if (num == ONIGERR_TOO_BIG_NUMBER)
-            return ONIGERR_TOO_BIG_WIDE_CHAR_VALUE;
-          else
-            return num;
-        }
+        r = scan_hexadecimal_number(&p, end, 0, 8, enc, &code);
+        if (r < 0) return r;
         if (!PEND) {
           c2 = PPEEK;
           if (IS_CODE_XDIGIT_ASCII(enc, c2))
@@ -4848,7 +4829,7 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
           PINC;
           tok->type   = TK_CODE_POINT;
           tok->base   = 16;
-          tok->u.code = (OnigCodePoint )num;
+          tok->u.code = code;
         }
         else {
           /* can't read nothing or invalid format */
@@ -4856,14 +4837,14 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         }
       }
       else if (IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_X_HEX2)) {
-        num = scan_unsigned_hexadecimal_number(&p, end, 0, 2, enc);
-        if (num < 0) return num;
+        r = scan_hexadecimal_number(&p, end, 0, 2, enc, &code);
+        if (r < 0) return r;
         if (p == prev) {  /* can't read nothing. */
-          num = 0; /* but, it's not error */
+          code = 0; /* but, it's not error */
         }
-        tok->type = TK_RAW_BYTE;
+        tok->type = TK_CRUDE_BYTE;
         tok->base = 16;
-        tok->u.c  = num;
+        tok->u.byte = (UChar )code;
       }
       break;
 
@@ -4872,14 +4853,14 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
       prev = p;
       if (IS_SYNTAX_OP2(syn, ONIG_SYN_OP2_ESC_U_HEX4)) {
-        num = scan_unsigned_hexadecimal_number(&p, end, 4, 4, enc);
-        if (num < 0) return num;
+        r = scan_hexadecimal_number(&p, end, 4, 4, enc, &code);
+        if (r < 0) return r;
         if (p == prev) {  /* can't read nothing. */
-          num = 0; /* but, it's not error */
+          code = 0; /* but, it's not error */
         }
         tok->type   = TK_CODE_POINT;
         tok->base   = 16;
-        tok->u.code = (OnigCodePoint )num;
+        tok->u.code = code;
       }
       break;
 
@@ -4888,22 +4869,23 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       if (IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_OCTAL3)) {
         PUNFETCH;
         prev = p;
-        num = scan_unsigned_octal_number(&p, end, 3, enc);
-        if (num < 0 || num >= 256) return ONIGERR_TOO_BIG_NUMBER;
+        r = scan_octal_number(&p, end, 0, 3, enc, &code);
+        if (r < 0) return r;
+        if (code >= 256) return ONIGERR_TOO_BIG_NUMBER;
         if (p == prev) {  /* can't read nothing. */
-          num = 0; /* but, it's not error */
+          code = 0; /* but, it's not error */
         }
-        tok->type = TK_RAW_BYTE;
+        tok->type = TK_CRUDE_BYTE;
         tok->base = 8;
-        tok->u.c  = num;
+        tok->u.byte = (UChar )code;
       }
       break;
 
     default:
       PUNFETCH;
-      num = fetch_escaped_value(&p, end, env, &c2);
-      if (num < 0) return num;
-      if (tok->u.c != c2) {
+      r = fetch_escaped_value(&p, end, env, &c2);
+      if (r < 0) return r;
+      if (tok->u.code != c2) {
         tok->u.code = c2;
         tok->type   = TK_CODE_POINT;
       }
@@ -4917,7 +4899,7 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       PINC;
       if (str_exist_check_with_esc(send, 2, p, end,
                                    (OnigCodePoint )']', enc, syn)) {
-        tok->type = TK_POSIX_BRACKET_OPEN;
+        tok->type = TK_CC_POSIX_BRACKET_OPEN;
       }
       else {
         PUNFETCH;
@@ -4927,7 +4909,7 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     else {
     cc_in_cc:
       if (IS_SYNTAX_OP2(syn, ONIG_SYN_OP2_CCLASS_SET_OP)) {
-        tok->type = TK_CC_CC_OPEN;
+        tok->type = TK_CC_OPEN_CC;
       }
       else {
         CC_ESC_WARN(env, (UChar* )"[");
@@ -4950,7 +4932,8 @@ fetch_token_in_cc(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 static int
 fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 {
-  int r, num;
+  int r;
+  OnigCodePoint code;
   OnigCodePoint c;
   OnigEncoding enc = env->enc;
   OnigSyntaxType* syn = env->syntax;
@@ -4975,7 +4958,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     tok->backp = p;
     PFETCH(c);
 
-    tok->u.c = c;
+    tok->u.code = c;
     tok->escaped = 1;
     switch (c) {
     case '*':
@@ -5026,7 +5009,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
     case '{':
       if (! IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_BRACE_INTERVAL)) break;
-      r = fetch_interval_quantifier(&p, end, tok, env);
+      r = fetch_interval(&p, end, tok, env);
       if (r < 0) return r;  /* error */
       if (r == 0) goto greedy_check2;
       else if (r == 2) { /* {n} */
@@ -5214,8 +5197,8 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       prev = p;
       if (PPEEK_IS('{') && IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_O_BRACE_OCTAL)) {
         PINC;
-        num = scan_unsigned_octal_number(&p, end, 11, enc);
-        if (num < 0) return ONIGERR_TOO_BIG_WIDE_CHAR_VALUE;
+        r = scan_octal_number(&p, end, 0, 11, enc, &code);
+        if (r < 0) return r;
         if (!PEND) {
           if (IS_CODE_DIGIT_ASCII(enc, PPEEK))
             return ONIGERR_TOO_LONG_WIDE_CHAR_VALUE;
@@ -5224,7 +5207,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         if ((p > prev + enclen(enc, prev)) && !PEND && PPEEK_IS('}')) {
           PINC;
           tok->type   = TK_CODE_POINT;
-          tok->u.code = (OnigCodePoint )num;
+          tok->u.code = code;
         }
         else {
           /* can't read nothing or invalid format */
@@ -5239,13 +5222,8 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       prev = p;
       if (PPEEK_IS('{') && IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_X_BRACE_HEX8)) {
         PINC;
-        num = scan_unsigned_hexadecimal_number(&p, end, 0, 8, enc);
-        if (num < 0) {
-          if (num == ONIGERR_TOO_BIG_NUMBER)
-            return ONIGERR_TOO_BIG_WIDE_CHAR_VALUE;
-          else
-            return num;
-        }
+        r = scan_hexadecimal_number(&p, end, 0, 8, enc, &code);
+        if (r < 0) return r;
         if (!PEND) {
           if (IS_CODE_XDIGIT_ASCII(enc, PPEEK))
             return ONIGERR_TOO_LONG_WIDE_CHAR_VALUE;
@@ -5254,7 +5232,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         if ((p > prev + enclen(enc, prev)) && !PEND && PPEEK_IS('}')) {
           PINC;
           tok->type   = TK_CODE_POINT;
-          tok->u.code = (OnigCodePoint )num;
+          tok->u.code = code;
         }
         else {
           /* can't read nothing or invalid format */
@@ -5262,14 +5240,14 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         }
       }
       else if (IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_X_HEX2)) {
-        num = scan_unsigned_hexadecimal_number(&p, end, 0, 2, enc);
-        if (num < 0) return num;
+        r = scan_hexadecimal_number(&p, end, 0, 2, enc, &code);
+        if (r < 0) return r;
         if (p == prev) {  /* can't read nothing. */
-          num = 0; /* but, it's not error */
+          code = 0; /* but, it's not error */
         }
-        tok->type = TK_RAW_BYTE;
+        tok->type = TK_CRUDE_BYTE;
         tok->base = 16;
-        tok->u.c  = num;
+        tok->u.byte = (UChar )code;
       }
       break;
 
@@ -5278,14 +5256,14 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
       prev = p;
       if (IS_SYNTAX_OP2(syn, ONIG_SYN_OP2_ESC_U_HEX4)) {
-        num = scan_unsigned_hexadecimal_number(&p, end, 4, 4, enc);
-        if (num < 0) return num;
+        r = scan_hexadecimal_number(&p, end, 4, 4, enc, &code);
+        if (r < 0) return r;
         if (p == prev) {  /* can't read nothing. */
-          num = 0; /* but, it's not error */
+          code = 0; /* but, it's not error */
         }
         tok->type   = TK_CODE_POINT;
         tok->base   = 16;
-        tok->u.code = (OnigCodePoint )num;
+        tok->u.code = code;
       }
       break;
 
@@ -5293,21 +5271,21 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     case '5': case '6': case '7': case '8': case '9':
       PUNFETCH;
       prev = p;
-      num = onig_scan_unsigned_number(&p, end, enc);
-      if (num < 0 || num > ONIG_MAX_BACKREF_NUM) {
+      r = scan_number(&p, end, enc);
+      if (r < 0 || r > ONIG_MAX_BACKREF_NUM) {
         goto skip_backref;
       }
 
       if (IS_SYNTAX_OP(syn, ONIG_SYN_OP_DECIMAL_BACKREF) &&
-          (num <= env->num_mem || num <= 9)) { /* This spec. from GNU regex */
+          (r <= env->num_mem || r <= 9)) { /* This spec. from GNU regex */
         if (IS_SYNTAX_BV(syn, ONIG_SYN_STRICT_CHECK_BACKREF)) {
-          if (num > env->num_mem || IS_NULL(SCANENV_MEMENV(env)[num].node))
+          if (r > env->num_mem || IS_NULL(SCANENV_MEMENV(env)[r].mem_node))
             return ONIGERR_INVALID_BACKREF;
         }
 
         tok->type = TK_BACKREF;
         tok->u.backref.num     = 1;
-        tok->u.backref.ref1    = num;
+        tok->u.backref.ref1    = r;
         tok->u.backref.by_name = 0;
 #ifdef USE_BACKREF_WITH_LEVEL
         tok->u.backref.exist_level = 0;
@@ -5327,14 +5305,14 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     case '0':
       if (IS_SYNTAX_OP(syn, ONIG_SYN_OP_ESC_OCTAL3)) {
         prev = p;
-        num = scan_unsigned_octal_number(&p, end, (c == '0' ? 2:3), enc);
-        if (num < 0 || num >= 256) return ONIGERR_TOO_BIG_NUMBER;
+        r = scan_octal_number(&p, end, 0, (c == '0' ? 2:3), enc, &code);
+        if (r < 0 || r >= 256) return ONIGERR_TOO_BIG_NUMBER;
         if (p == prev) {  /* can't read nothing. */
-          num = 0; /* but, it's not error */
+          code = 0; /* but, it's not error */
         }
-        tok->type = TK_RAW_BYTE;
+        tok->type = TK_CRUDE_BYTE;
         tok->base = 8;
-        tok->u.c  = num;
+        tok->u.byte = (UChar )code;
       }
       else if (c != '0') {
         PINC;
@@ -5359,7 +5337,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
           if (r == 1) tok->u.backref.exist_level = 1;
           else        tok->u.backref.exist_level = 0;
 #else
-          r = fetch_name(c, &p, end, &name_end, env, &back_num, &num_type, 1);
+          r = fetch_name(c, &p, end, &name_end, env, &back_num, &num_type, TRUE);
 #endif
           if (r < 0) return r;
 
@@ -5372,7 +5350,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
             if (IS_SYNTAX_BV(syn, ONIG_SYN_STRICT_CHECK_BACKREF)) {
               if (back_num > env->num_mem ||
-                  IS_NULL(SCANENV_MEMENV(env)[back_num].node))
+                  IS_NULL(SCANENV_MEMENV(env)[back_num].mem_node))
                 return ONIGERR_INVALID_BACKREF;
             }
             tok->type = TK_BACKREF;
@@ -5381,7 +5359,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
             tok->u.backref.ref1 = back_num;
           }
           else {
-            num = name_to_group_numbers(env, prev, name_end, &backs);
+            int num = name_to_group_numbers(env, prev, name_end, &backs);
             if (num <= 0) {
               return ONIGERR_UNDEFINED_NAME_REFERENCE;
             }
@@ -5389,7 +5367,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
               int i;
               for (i = 0; i < num; i++) {
                 if (backs[i] > env->num_mem ||
-                    IS_NULL(SCANENV_MEMENV(env)[backs[i]].node))
+                    IS_NULL(SCANENV_MEMENV(env)[backs[i]].mem_node))
                   return ONIGERR_INVALID_BACKREF;
               }
             }
@@ -5422,7 +5400,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
           prev = p;
           r = fetch_name((OnigCodePoint )c, &p, end, &name_end, env,
-                         &gnum, &num_type, 1);
+                         &gnum, &num_type, TRUE);
           if (r < 0) return r;
 
           if (num_type != IS_NOT_NUM) {
@@ -5483,10 +5461,9 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         OnigCodePoint c2;
 
         PUNFETCH;
-        num = fetch_escaped_value(&p, end, env, &c2);
-        if (num < 0) return num;
-        /* set_raw: */
-        if (tok->u.c != c2) {
+        r = fetch_escaped_value(&p, end, env, &c2);
+        if (r < 0) return r;
+        if (tok->u.code != c2) {
           tok->type = TK_CODE_POINT;
           tok->u.code = c2;
         }
@@ -5498,7 +5475,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     }
   }
   else {
-    tok->u.c = c;
+    tok->u.code = c;
     tok->escaped = 0;
 
 #ifdef USE_VARIABLE_META_CHARS
@@ -5563,7 +5540,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
     case '{':
       if (! IS_SYNTAX_OP(syn, ONIG_SYN_OP_BRACE_INTERVAL)) break;
-      r = fetch_interval_quantifier(&p, end, tok, env);
+      r = fetch_interval(&p, end, tok, env);
       if (r < 0) return r;  /* error */
       if (r == 0) goto greedy_check2;
       else if (r == 2) { /* {n} */
@@ -5611,8 +5588,8 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
               {
                 PINC;
                 name = p;
-                r = fetch_name((OnigCodePoint )'(', &p, end, &name_end, env, &gnum,
-                               &num_type, 0);
+                r = fetch_name((OnigCodePoint )'(', &p, end, &name_end, env,
+                               &gnum, &num_type, FALSE);
                 if (r < 0) return r;
 
                 tok->type = TK_CALL;
@@ -5644,7 +5621,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
               {
                 name = p;
                 r = fetch_name((OnigCodePoint )'(', &p, end, &name_end, env,
-                               &gnum, &num_type, 1);
+                               &gnum, &num_type, TRUE);
                 if (r < 0) return r;
 
                 if (num_type == IS_NOT_NUM) {
@@ -5700,7 +5677,7 @@ fetch_token(PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
     case '[':
       if (! IS_SYNTAX_OP(syn, ONIG_SYN_OP_BRACKET_CC)) break;
-      tok->type = TK_CC_OPEN;
+      tok->type = TK_OPEN_CC;
       break;
 
     case ']':
@@ -5911,6 +5888,7 @@ add_ctype_to_cc(CClassNode* cc, int ctype, int not, ScanEnv* env)
 
   int c, r;
   int ascii_mode;
+  int is_single;
   const OnigCodePoint *ranges;
   OnigCodePoint limit;
   OnigCodePoint sb_out;
@@ -5932,6 +5910,7 @@ add_ctype_to_cc(CClassNode* cc, int ctype, int not, ScanEnv* env)
   }
 
   r = 0;
+  is_single = ONIGENC_IS_SINGLEBYTE(enc);
   limit = ascii_mode ? ASCII_LIMIT : SINGLE_BYTE_SIZE;
 
   switch (ctype) {
@@ -5948,19 +5927,25 @@ add_ctype_to_cc(CClassNode* cc, int ctype, int not, ScanEnv* env)
   case ONIGENC_CTYPE_ALNUM:
     if (not != 0) {
       for (c = 0; c < (int )limit; c++) {
-        if (! ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
-          BITSET_SET_BIT(cc->bs, c);
+        if (is_single != 0 || ONIGENC_CODE_TO_MBCLEN(enc, c) == 1) {
+          if (! ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
+            BITSET_SET_BIT(cc->bs, c);
+        }
       }
       for (c = limit; c < SINGLE_BYTE_SIZE; c++) {
-        BITSET_SET_BIT(cc->bs, c);
+        if (is_single != 0 || ONIGENC_CODE_TO_MBCLEN(enc, c) == 1)
+          BITSET_SET_BIT(cc->bs, c);
       }
 
-      ADD_ALL_MULTI_BYTE_RANGE(enc, cc->mbuf);
+      if (is_single == 0)
+        ADD_ALL_MULTI_BYTE_RANGE(enc, cc->mbuf);
     }
     else {
       for (c = 0; c < (int )limit; c++) {
-        if (ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
-          BITSET_SET_BIT(cc->bs, c);
+        if (is_single != 0 || ONIGENC_CODE_TO_MBCLEN(enc, c) == 1) {
+          if (ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
+            BITSET_SET_BIT(cc->bs, c);
+        }
       }
     }
     break;
@@ -5970,21 +5955,25 @@ add_ctype_to_cc(CClassNode* cc, int ctype, int not, ScanEnv* env)
   case ONIGENC_CTYPE_WORD:
     if (not != 0) {
       for (c = 0; c < (int )limit; c++) {
-        if (ONIGENC_CODE_TO_MBCLEN(enc, c) > 0 /* check invalid code point */
+        /* check invalid code point */
+        if ((is_single != 0 || ONIGENC_CODE_TO_MBCLEN(enc, c) == 1)
             && ! ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
           BITSET_SET_BIT(cc->bs, c);
       }
       for (c = limit; c < SINGLE_BYTE_SIZE; c++) {
-        if (ONIGENC_CODE_TO_MBCLEN(enc, c) > 0)
+        if (is_single != 0 || ONIGENC_CODE_TO_MBCLEN(enc, c) == 1)
           BITSET_SET_BIT(cc->bs, c);
       }
+      if (ascii_mode != 0 && is_single == 0)
+        ADD_ALL_MULTI_BYTE_RANGE(enc, cc->mbuf);
     }
     else {
       for (c = 0; c < (int )limit; c++) {
-        if (ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
+        if ((is_single != 0 || ONIGENC_CODE_TO_MBCLEN(enc, c) == 1)
+            && ONIGENC_IS_CODE_CTYPE(enc, (OnigCodePoint )c, ctype))
           BITSET_SET_BIT(cc->bs, c);
       }
-      if (ascii_mode == 0)
+      if (ascii_mode == 0 && is_single == 0)
         ADD_ALL_MULTI_BYTE_RANGE(enc, cc->mbuf);
     }
     break;
@@ -6076,10 +6065,12 @@ fetch_char_property_to_ctype(UChar** src, UChar* end, ScanEnv* env)
 {
   int r;
   OnigCodePoint c;
-  OnigEncoding enc = env->enc;
-  UChar *prev, *start, *p = *src;
+  OnigEncoding enc;
+  UChar *prev, *start, *p;
 
-  r = 0;
+  p = *src;
+  enc = env->enc;
+  r = ONIGERR_END_PATTERN_WITH_UNMATCHED_PARENTHESIS;
   start = prev = p;
 
   while (!PEND) {
@@ -6087,18 +6078,20 @@ fetch_char_property_to_ctype(UChar** src, UChar* end, ScanEnv* env)
     PFETCH_S(c);
     if (c == '}') {
       r = ONIGENC_PROPERTY_NAME_TO_CTYPE(enc, start, prev);
-      if (r < 0) break;
+      if (r >= 0) {
+        *src = p;
+      }
+      else {
+        onig_scan_env_set_error_string(env, r, *src, prev);
+      }
 
-      *src = p;
       return r;
     }
     else if (c == '(' || c == ')' || c == '{' || c == '|') {
-      r = ONIGERR_INVALID_CHAR_PROPERTY_NAME;
       break;
     }
   }
 
-  onig_scan_env_set_error_string(env, r, *src, prev);
   return r;
 }
 
@@ -6114,7 +6107,7 @@ parse_char_property(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* en
   *np = node_new_cclass();
   CHECK_NULL_RETURN_MEMERR(*np);
   cc = CCLASS_(*np);
-  r = add_ctype_to_cc(cc, ctype, 0, env);
+  r = add_ctype_to_cc(cc, ctype, FALSE, env);
   if (r != 0) return r;
   if (tok->u.prop.not != 0) NCCLASS_SET_NOT(cc);
 
@@ -6122,67 +6115,67 @@ parse_char_property(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* en
 }
 
 
-enum CCSTATE {
-  CCS_VALUE,
-  CCS_RANGE,
-  CCS_COMPLETE,
-  CCS_START
-};
+typedef enum {
+  CS_VALUE,
+  CS_RANGE,
+  CS_COMPLETE,
+  CS_START
+} CSTATE;
 
-enum CCVALTYPE {
-  CCV_SB,
-  CCV_CODE_POINT,
-  CCV_CLASS
-};
+typedef enum {
+  CV_UNDEF,
+  CV_SB,
+  CV_MB,
+  CV_CPROP
+} CVAL;
 
 static int
-next_state_class(CClassNode* cc, OnigCodePoint* vs, enum CCVALTYPE* type,
-                 enum CCSTATE* state, ScanEnv* env)
+cc_cprop_next(CClassNode* cc, OnigCodePoint* pcode, CVAL* val, CSTATE* state,
+              ScanEnv* env)
 {
   int r;
 
-  if (*state == CCS_RANGE)
+  if (*state == CS_RANGE)
     return ONIGERR_CHAR_CLASS_VALUE_AT_END_OF_RANGE;
 
-  if (*state == CCS_VALUE && *type != CCV_CLASS) {
-    if (*type == CCV_SB)
-      BITSET_SET_BIT(cc->bs, (int )(*vs));
-    else if (*type == CCV_CODE_POINT) {
-      r = add_code_range(&(cc->mbuf), env, *vs, *vs);
+  if (*state == CS_VALUE) {
+    if (*val == CV_SB)
+      BITSET_SET_BIT(cc->bs, (int )(*pcode));
+    else if (*val == CV_MB) {
+      r = add_code_range(&(cc->mbuf), env, *pcode, *pcode);
       if (r < 0) return r;
     }
   }
 
-  *state = CCS_VALUE;
-  *type  = CCV_CLASS;
+  *state = CS_VALUE;
+  *val   = CV_CPROP;
   return 0;
 }
 
 static int
-next_state_val(CClassNode* cc, OnigCodePoint *from, OnigCodePoint to,
-               int* from_israw, int to_israw,
-               enum CCVALTYPE intype, enum CCVALTYPE* type,
-               enum CCSTATE* state, ScanEnv* env)
+cc_char_next(CClassNode* cc, OnigCodePoint *from, OnigCodePoint to,
+             int* from_raw, int to_raw, CVAL intype, CVAL* type,
+             CSTATE* state, ScanEnv* env)
 {
   int r;
 
   switch (*state) {
-  case CCS_VALUE:
-    if (*type == CCV_SB) {
+  case CS_VALUE:
+    if (*type == CV_SB) {
       if (*from > 0xff)
           return ONIGERR_INVALID_CODE_POINT_VALUE;
 
       BITSET_SET_BIT(cc->bs, (int )(*from));
     }
-    else if (*type == CCV_CODE_POINT) {
+    else if (*type == CV_MB) {
       r = add_code_range(&(cc->mbuf), env, *from, *from);
       if (r < 0) return r;
     }
     break;
 
-  case CCS_RANGE:
+  case CS_RANGE:
     if (intype == *type) {
-      if (intype == CCV_SB) {
+      if (intype == CV_SB) {
         if (*from > 0xff || to > 0xff)
           return ONIGERR_INVALID_CODE_POINT_VALUE;
 
@@ -6211,21 +6204,21 @@ next_state_val(CClassNode* cc, OnigCodePoint *from, OnigCodePoint to,
       if (r < 0) return r;
     }
   ccs_range_end:
-    *state = CCS_COMPLETE;
+    *state = CS_COMPLETE;
     break;
 
-  case CCS_COMPLETE:
-  case CCS_START:
-    *state = CCS_VALUE;
+  case CS_COMPLETE:
+  case CS_START:
+    *state = CS_VALUE;
     break;
 
   default:
     break;
   }
 
-  *from_israw = to_israw;
-  *from       = to;
-  *type       = intype;
+  *from_raw = to_raw;
+  *from     = to;
+  *type     = intype;
   return 0;
 }
 
@@ -6253,27 +6246,25 @@ code_exist_check(OnigCodePoint c, UChar* from, UChar* end, int ignore_escaped,
 }
 
 static int
-parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
+parse_cc(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 {
   int r, neg, len, fetched, and_start;
-  OnigCodePoint v, vs;
+  OnigCodePoint in_code, curr_code;
   UChar *p;
   Node* node;
   CClassNode *cc, *prev_cc;
   CClassNode work_cc;
-
-  enum CCSTATE state;
-  enum CCVALTYPE val_type, in_type;
-  int val_israw, in_israw;
+  int curr_raw, in_raw;
+  CSTATE state;
+  CVAL in_type;
+  CVAL curr_type;
 
   *np = NULL_NODE;
-  env->parse_depth++;
-  if (env->parse_depth > ParseDepthLimit)
-    return ONIGERR_PARSE_DEPTH_LIMIT_OVER;
+  INC_PARSE_DEPTH(env->parse_depth);
 
   prev_cc = (CClassNode* )NULL;
   r = fetch_token_in_cc(tok, src, end, env);
-  if (r == TK_CHAR && tok->u.c == '^' && tok->escaped == 0) {
+  if (r == TK_CHAR && tok->u.code == (OnigCodePoint )'^' && tok->escaped == 0) {
     neg = 1;
     r = fetch_token_in_cc(tok, src, end, env);
   }
@@ -6296,31 +6287,27 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
   cc = CCLASS_(node);
 
   and_start = 0;
-  state = CCS_START;
+  state = CS_START;
+  curr_type = CV_UNDEF;
+
   p = *src;
   while (r != TK_CC_CLOSE) {
     fetched = 0;
     switch (r) {
     case TK_CHAR:
     any_char_in:
-      len = ONIGENC_CODE_TO_MBCLEN(env->enc, tok->u.c);
-      if (len > 1) {
-        in_type = CCV_CODE_POINT;
-      }
-      else if (len < 0) {
+      len = ONIGENC_CODE_TO_MBCLEN(env->enc, tok->u.code);
+      if (len < 0) {
         r = len;
         goto err;
       }
-      else {
-        /* sb_char: */
-        in_type = CCV_SB;
-      }
-      v = (OnigCodePoint )tok->u.c;
-      in_israw = 0;
+      in_type = (len == 1) ? CV_SB : CV_MB;
+      in_code = tok->u.code;
+      in_raw = 0;
       goto val_entry2;
       break;
 
-    case TK_RAW_BYTE:
+    case TK_CRUDE_BYTE:
       /* tok->base != 0 : octal or hexadec. */
       if (! ONIGENC_IS_SINGLEBYTE(env->enc) && tok->base != 0) {
         int i, j;
@@ -6329,15 +6316,15 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         UChar* psave = p;
         int base = tok->base;
 
-        buf[0] = tok->u.c;
+        buf[0] = tok->u.byte;
         for (i = 1; i < ONIGENC_MBC_MAXLEN(env->enc); i++) {
           r = fetch_token_in_cc(tok, &p, end, env);
           if (r < 0) goto err;
-          if (r != TK_RAW_BYTE || tok->base != base) {
+          if (r != TK_CRUDE_BYTE || tok->base != base) {
             fetched = 1;
             break;
           }
-          buf[i] = tok->u.c;
+          buf[i] = tok->u.byte;
         }
 
         if (i < ONIGENC_MBC_MINLEN(env->enc)) {
@@ -6362,63 +6349,63 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         }
 
         if (i == 1) {
-          v = (OnigCodePoint )buf[0];
-          goto raw_single;
+          in_code = (OnigCodePoint )buf[0];
+          goto crude_single;
         }
         else {
-          v = ONIGENC_MBC_TO_CODE(env->enc, buf, bufe);
-          in_type = CCV_CODE_POINT;
+          in_code = ONIGENC_MBC_TO_CODE(env->enc, buf, bufe);
+          in_type = CV_MB;
         }
       }
       else {
-        v = (OnigCodePoint )tok->u.c;
-      raw_single:
-        in_type = CCV_SB;
+        in_code = (OnigCodePoint )tok->u.byte;
+      crude_single:
+        in_type = CV_SB;
       }
-      in_israw = 1;
+      in_raw = 1;
       goto val_entry2;
       break;
 
     case TK_CODE_POINT:
-      v = tok->u.code;
-      in_israw = 1;
+      in_code = tok->u.code;
+      in_raw  = 1;
     val_entry:
-      len = ONIGENC_CODE_TO_MBCLEN(env->enc, v);
+      len = ONIGENC_CODE_TO_MBCLEN(env->enc, in_code);
       if (len < 0) {
-        if (state != CCS_RANGE ||
+        if (state != CS_RANGE ||
             ! IS_SYNTAX_BV(env->syntax,
                            ONIG_SYN_ALLOW_INVALID_CODE_END_OF_RANGE_IN_CC) ||
-            v < 0x100 || ONIGENC_MBC_MAXLEN(env->enc) == 1) {
+            in_code < 0x100 || ONIGENC_MBC_MAXLEN(env->enc) == 1) {
           r = len;
           goto err;
         }
       }
-      in_type = (len == 1 ? CCV_SB : CCV_CODE_POINT);
+      in_type = (len == 1 ? CV_SB : CV_MB);
     val_entry2:
-      r = next_state_val(cc, &vs, v, &val_israw, in_israw, in_type, &val_type,
-                         &state, env);
+      r = cc_char_next(cc, &curr_code, in_code, &curr_raw, in_raw, in_type,
+                       &curr_type, &state, env);
       if (r != 0) goto err;
       break;
 
-    case TK_POSIX_BRACKET_OPEN:
+    case TK_CC_POSIX_BRACKET_OPEN:
       r = parse_posix_bracket(cc, &p, end, env);
       if (r < 0) goto err;
       if (r == 1) {  /* is not POSIX bracket */
         CC_ESC_WARN(env, (UChar* )"[");
         p = tok->backp;
-        v = (OnigCodePoint )tok->u.c;
-        in_israw = 0;
+        in_code = tok->u.code;
+        in_raw = 0;
         goto val_entry;
       }
-      goto next_class;
+      goto next_cprop;
       break;
 
     case TK_CHAR_TYPE:
       r = add_ctype_to_cc(cc, tok->u.prop.ctype, tok->u.prop.not, env);
       if (r != 0) goto err;
 
-    next_class:
-      r = next_state_class(cc, &vs, &val_type, &state, env);
+    next_cprop:
+      r = cc_cprop_next(cc, &curr_code, &curr_type, &state, env);
       if (r != 0) goto err;
       break;
 
@@ -6431,19 +6418,20 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
         }
         r = add_ctype_to_cc(cc, ctype, tok->u.prop.not, env);
         if (r != 0) goto err;
-        goto next_class;
+        goto next_cprop;
       }
       break;
 
     case TK_CC_RANGE:
-      if (state == CCS_VALUE) {
+      if (state == CS_VALUE) {
         r = fetch_token_in_cc(tok, &p, end, env);
         if (r < 0) goto err;
+
         fetched = 1;
         if (r == TK_CC_CLOSE) { /* allow [x-] */
         range_end_val:
-          v = (OnigCodePoint )'-';
-          in_israw = 0;
+          in_code = (OnigCodePoint )'-';
+          in_raw = 0;
           goto val_entry;
         }
         else if (r == TK_CC_AND) {
@@ -6451,20 +6439,21 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
           goto range_end_val;
         }
 
-        if (val_type == CCV_CLASS) {
+        if (curr_type == CV_CPROP) {
           r = ONIGERR_UNMATCHED_RANGE_SPECIFIER_IN_CHAR_CLASS;
           goto err;
         }
 
-        state = CCS_RANGE;
+        state = CS_RANGE;
       }
-      else if (state == CCS_START) {
+      else if (state == CS_START) {
         /* [-xa] is allowed */
-        v = (OnigCodePoint )tok->u.c;
-        in_israw = 0;
+        in_code = tok->u.code;
+        in_raw = 0;
 
         r = fetch_token_in_cc(tok, &p, end, env);
         if (r < 0) goto err;
+
         fetched = 1;
         /* [--x] or [a&&-x] is warned. */
         if (r == TK_CC_RANGE || and_start != 0)
@@ -6472,15 +6461,17 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
         goto val_entry;
       }
-      else if (state == CCS_RANGE) {
+      else if (state == CS_RANGE) {
         CC_ESC_WARN(env, (UChar* )"-");
-        goto any_char_in;  /* [!--x] is allowed */
+        goto any_char_in;  /* [!--] is allowed */
       }
-      else { /* CCS_COMPLETE */
+      else { /* CS_COMPLETE */
         r = fetch_token_in_cc(tok, &p, end, env);
         if (r < 0) goto err;
+
         fetched = 1;
-        if (r == TK_CC_CLOSE) goto range_end_val; /* allow [a-b-] */
+        if (r == TK_CC_CLOSE)
+          goto range_end_val; /* allow [a-b-] */
         else if (r == TK_CC_AND) {
           CC_ESC_WARN(env, (UChar* )"-");
           goto range_end_val;
@@ -6495,12 +6486,19 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
       }
       break;
 
-    case TK_CC_CC_OPEN: /* [ */
+    case TK_CC_OPEN_CC: /* [ */
       {
         Node *anode;
         CClassNode* acc;
 
-        r = parse_char_class(&anode, tok, &p, end, env);
+        if (state == CS_VALUE) {
+          r = cc_char_next(cc, &curr_code, 0, &curr_raw, 0, curr_type, &curr_type,
+                           &state, env);
+          if (r != 0) goto err;
+        }
+        state = CS_COMPLETE;
+
+        r = parse_cc(&anode, tok, &p, end, env);
         if (r != 0) {
           onig_node_free(anode);
           goto cc_open_err;
@@ -6516,14 +6514,14 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
 
     case TK_CC_AND: /* && */
       {
-        if (state == CCS_VALUE) {
-          r = next_state_val(cc, &vs, 0, &val_israw, 0, val_type,
-                             &val_type, &state, env);
+        if (state == CS_VALUE) {
+          r = cc_char_next(cc, &curr_code, 0, &curr_raw, 0, curr_type, &curr_type,
+                           &state, env);
           if (r != 0) goto err;
         }
         /* initialize local variables */
         and_start = 1;
-        state = CCS_START;
+        state = CS_START;
 
         if (IS_NOT_NULL(prev_cc)) {
           r = and_cclass(prev_cc, cc, env->enc);
@@ -6556,9 +6554,9 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     }
   }
 
-  if (state == CCS_VALUE) {
-    r = next_state_val(cc, &vs, 0, &val_israw, 0, val_type,
-                       &val_type, &state, env);
+  if (state == CS_VALUE) {
+    r = cc_char_next(cc, &curr_code, 0, &curr_raw, 0, curr_type, &curr_type,
+                     &state, env);
     if (r != 0) goto err;
   }
 
@@ -6591,7 +6589,7 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
     }
   }
   *src = p;
-  env->parse_depth--;
+  DEC_PARSE_DEPTH(env->parse_depth);
   return 0;
 
  err:
@@ -6600,8 +6598,8 @@ parse_char_class(Node** np, PToken* tok, UChar** src, UChar* end, ScanEnv* env)
   return r;
 }
 
-static int parse_subexp(Node** top, PToken* tok, int term,
-                        UChar** src, UChar* end, ScanEnv* env, int group_head);
+static int parse_alts(Node** top, PToken* tok, int term,
+                      UChar** src, UChar* end, ScanEnv* env, int group_head);
 
 #ifdef USE_CALLOUT
 
@@ -6772,7 +6770,8 @@ parse_long(OnigEncoding enc, UChar* s, UChar* end, int sign_on, long max, long*
 
 static int
 parse_callout_args(int skip_mode, int cterm, UChar** src, UChar* end,
-                   unsigned int types[], OnigValue vals[], ScanEnv* env)
+                   int max_arg_num, unsigned int types[], OnigValue vals[],
+                   ScanEnv* env)
 {
 #define MAX_CALLOUT_ARG_BYTE_LENGTH   128
 
@@ -6791,9 +6790,9 @@ parse_callout_args(int skip_mode, int cterm, UChar** src, UChar* end,
 
   if (PEND) return ONIGERR_INVALID_CALLOUT_PATTERN;
 
+  c = 0;
   n = 0;
   while (n < ONIG_CALLOUT_MAX_ARGS_NUM) {
-    c   = 0;
     cn  = 0;
     esc = 0;
     eesc = 0;
@@ -6826,7 +6825,7 @@ parse_callout_args(int skip_mode, int cterm, UChar** src, UChar* end,
           size_t clen;
 
         add_char:
-          if (skip_mode == 0) {
+          if (skip_mode == FALSE) {
             clen = p - e;
             if (bufend + clen > buf + MAX_CALLOUT_ARG_BYTE_LENGTH)
               return ONIGERR_INVALID_CALLOUT_ARG; /* too long argument */
@@ -6840,7 +6839,10 @@ parse_callout_args(int skip_mode, int cterm, UChar** src, UChar* end,
     }
 
     if (cn != 0) {
-      if (skip_mode == 0) {
+      if (max_arg_num >= 0 && n >= max_arg_num)
+        return ONIGERR_INVALID_CALLOUT_ARG;
+
+      if (skip_mode == FALSE) {
         if ((types[n] & ONIG_TYPE_LONG) != 0) {
           int fixed = 0;
           if (cn > 0) {
@@ -6972,7 +6974,7 @@ parse_callout_of_name(Node** np, int cterm, UChar** src, UChar* end, ScanEnv* en
 
     /* read for single check only */
     save = p;
-    arg_num = parse_callout_args(1, '}', &p, end, 0, 0, env);
+    arg_num = parse_callout_args(TRUE, '}', &p, end, -1, NULL, NULL, env);
     if (arg_num < 0) return arg_num;
 
     is_not_single = PPEEK_IS(cterm) ?  0 : 1;
@@ -6986,7 +6988,7 @@ parse_callout_of_name(Node** np, int cterm, UChar** src, UChar* end, ScanEnv* en
       types[i] = get_callout_arg_type_by_name_id(name_id, i);
     }
 
-    arg_num = parse_callout_args(0, '}', &p, end, types, vals, env);
+    arg_num = parse_callout_args(FALSE, '}', &p, end, max_arg_num, types, vals, env);
     if (arg_num < 0) return arg_num;
 
     if (PEND) return ONIGERR_END_PATTERN_IN_GROUP;
@@ -7086,17 +7088,17 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
     group:
       r = fetch_token(tok, &p, end, env);
       if (r < 0) return r;
-      r = parse_subexp(np, tok, term, &p, end, env, 0);
+      r = parse_alts(np, tok, term, &p, end, env, FALSE);
       if (r < 0) return r;
       *src = p;
       return 1; /* group */
       break;
 
     case '=':
-      *np = onig_node_new_anchor(ANCR_PREC_READ, 0);
+      *np = onig_node_new_anchor(ANCR_PREC_READ, FALSE);
       break;
     case '!':  /*         preceding read */
-      *np = onig_node_new_anchor(ANCR_PREC_READ_NOT, 0);
+      *np = onig_node_new_anchor(ANCR_PREC_READ_NOT, FALSE);
       break;
     case '>':            /* (?>...) stop backtrack */
       *np = node_new_bag(BAG_STOP_BACKTRACK);
@@ -7114,9 +7116,9 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
       if (PEND) return ONIGERR_END_PATTERN_WITH_UNMATCHED_PARENTHESIS;
       PFETCH(c);
       if (c == '=')
-        *np = onig_node_new_anchor(ANCR_LOOK_BEHIND, 0);
+        *np = onig_node_new_anchor(ANCR_LOOK_BEHIND, FALSE);
       else if (c == '!')
-        *np = onig_node_new_anchor(ANCR_LOOK_BEHIND_NOT, 0);
+        *np = onig_node_new_anchor(ANCR_LOOK_BEHIND_NOT, FALSE);
       else {
         if (IS_SYNTAX_OP2(env->syntax, ONIG_SYN_OP2_QMARK_LT_NAMED_GROUP)) {
           UChar *name;
@@ -7132,7 +7134,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
         named_group2:
           name = p;
           r = fetch_name((OnigCodePoint )c, &p, end, &name_end, env, &num,
-                         &num_type, 0);
+                         &num_type, FALSE);
           if (r < 0) return r;
 
           num = scan_env_add_mem_entry(env);
@@ -7146,7 +7148,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
           CHECK_NULL_RETURN_MEMERR(*np);
           BAG_(*np)->m.regnum = num;
           if (list_capture != 0)
-            MEM_STATUS_ON_SIMPLE(env->capture_history, num);
+            MEM_STATUS_ON_SIMPLE(env->cap_history, num);
           env->num_named++;
         }
         else {
@@ -7181,7 +7183,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
 
         r = fetch_token(tok, &p, end, env);
         if (r < 0) return r;
-        r = parse_subexp(&absent, tok, term, &p, end, env, 1);
+        r = parse_alts(&absent, tok, term, &p, end, env, TRUE);
         if (r < 0) {
           onig_node_free(absent);
           return r;
@@ -7268,7 +7270,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
           if (r == 1) exist_level = 1;
 #else
           r = fetch_name((OnigCodePoint )(is_enclosed != 0 ? c : '('),
-                         &p, end, &name_end, env, &back_num, &num_type, 1);
+                         &p, end, &name_end, env, &back_num, &num_type, TRUE);
 #endif
           if (r < 0) {
             if (is_enclosed == 0) {
@@ -7288,11 +7290,11 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
 
             if (IS_SYNTAX_BV(env->syntax, ONIG_SYN_STRICT_CHECK_BACKREF)) {
               if (back_num > env->num_mem ||
-                  IS_NULL(SCANENV_MEMENV(env)[back_num].node))
+                  IS_NULL(SCANENV_MEMENV(env)[back_num].mem_node))
                 return ONIGERR_INVALID_BACKREF;
             }
 
-            condition = node_new_backref_checker(1, &back_num, 0,
+            condition = node_new_backref_checker(1, &back_num, FALSE,
 #ifdef USE_BACKREF_WITH_LEVEL
                                                  exist_level, level,
 #endif
@@ -7310,12 +7312,12 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
               int i;
               for (i = 0; i < num; i++) {
                 if (backs[i] > env->num_mem ||
-                    IS_NULL(SCANENV_MEMENV(env)[backs[i]].node))
+                    IS_NULL(SCANENV_MEMENV(env)[backs[i]].mem_node))
                   return ONIGERR_INVALID_BACKREF;
               }
             }
 
-            condition = node_new_backref_checker(num, backs, 1,
+            condition = node_new_backref_checker(num, backs, TRUE,
 #ifdef USE_BACKREF_WITH_LEVEL
                                                  exist_level, level,
 #endif
@@ -7357,7 +7359,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
           condition_is_checker = 0;
           r = fetch_token(tok, &p, end, env);
           if (r < 0) return r;
-          r = parse_subexp(&condition, tok, term, &p, end, env, 0);
+          r = parse_alts(&condition, tok, term, &p, end, env, FALSE);
           if (r < 0) {
             onig_node_free(condition);
             return r;
@@ -7400,7 +7402,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
             onig_node_free(condition);
             return r;
           }
-          r = parse_subexp(&target, tok, term, &p, end, env, 1);
+          r = parse_alts(&target, tok, term, &p, end, env, TRUE);
           if (r < 0) {
             onig_node_free(condition);
             onig_node_free(target);
@@ -7465,7 +7467,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
           return ONIGERR_GROUP_NUMBER_OVER_FOR_CAPTURE_HISTORY;
         }
         BAG_(*np)->m.regnum = num;
-        MEM_STATUS_ON_SIMPLE(env->capture_history, num);
+        MEM_STATUS_ON_SIMPLE(env->cap_history, num);
       }
       else {
         return ONIGERR_UNDEFINED_GROUP_OPTION;
@@ -7501,7 +7503,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
 
           case 'm':
             if (IS_SYNTAX_OP2(env->syntax, ONIG_SYN_OP2_OPTION_PERL)) {
-              OPTION_NEGATE(option, ONIG_OPTION_SINGLELINE, (neg == 0 ? 1 : 0));
+              OPTION_NEGATE(option, ONIG_OPTION_SINGLELINE, (neg == 0 ? TRUE : FALSE));
             }
             else if (IS_SYNTAX_OP2(env->syntax,
                         ONIG_SYN_OP2_OPTION_ONIGURUMA|ONIG_SYN_OP2_OPTION_RUBY)) {
@@ -7537,16 +7539,16 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
                 if (! ONIGENC_IS_UNICODE_ENCODING(enc))
                   return ONIGERR_UNDEFINED_GROUP_OPTION;
 
-                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_EXTENDED_GRAPHEME_CLUSTER, 0);
-                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_WORD, 1);
+                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_EXTENDED_GRAPHEME_CLUSTER, FALSE);
+                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_WORD, TRUE);
                 break;
 #ifdef USE_UNICODE_WORD_BREAK
               case 'w':
                 if (! ONIGENC_IS_UNICODE_ENCODING(enc))
                   return ONIGERR_UNDEFINED_GROUP_OPTION;
 
-                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_WORD, 0);
-                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_EXTENDED_GRAPHEME_CLUSTER, 1);
+                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_WORD, FALSE);
+                OPTION_NEGATE(option, ONIG_OPTION_TEXT_SEGMENT_EXTENDED_GRAPHEME_CLUSTER, TRUE);
                 break;
 #endif
               default:
@@ -7576,7 +7578,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
             env->options = option;
             r = fetch_token(tok, &p, end, env);
             if (r < 0) return r;
-            r = parse_subexp(&target, tok, term, &p, end, env, 0);
+            r = parse_alts(&target, tok, term, &p, end, env, FALSE);
             env->options = prev;
             if (r < 0) {
               onig_node_free(target);
@@ -7623,7 +7625,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
   CHECK_NULL_RETURN_MEMERR(*np);
   r = fetch_token(tok, &p, end, env);
   if (r < 0) return r;
-  r = parse_subexp(&target, tok, term, &p, end, env, 0);
+  r = parse_alts(&target, tok, term, &p, end, env, FALSE);
   if (r < 0) {
     onig_node_free(target);
     return r;
@@ -7633,7 +7635,7 @@ parse_bag(Node** np, PToken* tok, int term, UChar** src, UChar* end,
 
   if (NODE_TYPE(*np) == NODE_BAG) {
     if (BAG_(*np)->type == BAG_MEMORY) {
-      /* Don't move this to previous of parse_subexp() */
+      /* Don't move this to previous of parse_alts() */
       r = scan_env_set_mem_node(env, BAG_(*np)->m.regnum, *np);
       if (r != 0) return r;
     }
@@ -7653,7 +7655,7 @@ static const char* ReduceQStr[] = {
 };
 
 static int
-set_quantifier(Node* qnode, Node* target, int group, ScanEnv* env)
+assign_quantifier_body(Node* qnode, Node* target, int group, ScanEnv* env)
 {
   QuantNode* qn;
 
@@ -7725,9 +7727,11 @@ set_quantifier(Node* qnode, Node* target, int group, ScanEnv* env)
         }
       }
       else {
+        int r;
+
         NODE_BODY(qnode) = target;
-        onig_reduce_nested_quantifier(qnode, target);
-        goto q_exit;
+        r = onig_reduce_nested_quantifier(qnode);
+        return r;
       }
     }
     break;
@@ -7737,7 +7741,6 @@ set_quantifier(Node* qnode, Node* target, int group, ScanEnv* env)
   }
 
   NODE_BODY(qnode) = target;
- q_exit:
   return 0;
 }
 
@@ -7767,6 +7770,38 @@ clear_not_flag_cclass(CClassNode* cc, OnigEncoding enc)
 }
 #endif /* CASE_FOLD_IS_APPLIED_INSIDE_NEGATIVE_CCLASS */
 
+#define ADD_CODE_INTO_CC(cc, code, enc) do {\
+  if (ONIGENC_MBC_MINLEN(enc) > 1 || ONIGENC_CODE_TO_MBCLEN(enc, code) != 1) {\
+    add_code_range_to_buf(&((cc)->mbuf), code, code);\
+  }\
+  else {\
+    BITSET_SET_BIT((cc)->bs, code);\
+  }\
+} while (0)
+
+extern int
+onig_new_cclass_with_code_list(Node** rnode, OnigEncoding enc,
+                               int n, OnigCodePoint codes[])
+{
+  int i;
+  Node* node;
+  CClassNode* cc;
+
+  *rnode = NULL_NODE;
+
+  node = node_new_cclass();
+  CHECK_NULL_RETURN_MEMERR(node);
+
+  cc = CCLASS_(node);
+
+  for (i = 0; i < n; i++) {
+    ADD_CODE_INTO_CC(cc, codes[i], enc);
+  }
+
+  *rnode = node;
+  return 0;
+}
+
 typedef struct {
   ScanEnv*    env;
   CClassNode* cc;
@@ -7780,37 +7815,31 @@ i_apply_case_fold(OnigCodePoint from, OnigCodePoint to[], int to_len, void* arg)
   IApplyCaseFoldArg* iarg;
   ScanEnv* env;
   CClassNode* cc;
-  BitSetRef bs;
 
   iarg = (IApplyCaseFoldArg* )arg;
   env = iarg->env;
   cc  = iarg->cc;
-  bs = cc->bs;
 
   if (to_len == 1) {
     int is_in = onig_is_code_in_cc(env->enc, from, cc);
 #ifdef CASE_FOLD_IS_APPLIED_INSIDE_NEGATIVE_CCLASS
     if ((is_in != 0 && !IS_NCCLASS_NOT(cc)) ||
         (is_in == 0 &&  IS_NCCLASS_NOT(cc))) {
-      if (ONIGENC_MBC_MINLEN(env->enc) > 1 || *to >= SINGLE_BYTE_SIZE) {
-        add_code_range(&(cc->mbuf), env, *to, *to);
-      }
-      else {
-        BITSET_SET_BIT(bs, *to);
-      }
+      ADD_CODE_INTO_CC(cc, *to, env->enc);
     }
 #else
     if (is_in != 0) {
-      if (ONIGENC_MBC_MINLEN(env->enc) > 1 || *to >= SINGLE_BYTE_SIZE) {
+      if (ONIGENC_MBC_MINLEN(env->enc) > 1 ||
+          ONIGENC_CODE_TO_MBCLEN(env->enc, *to) != 1) {
         if (IS_NCCLASS_NOT(cc)) clear_not_flag_cclass(cc, env->enc);
         add_code_range(&(cc->mbuf), env, *to, *to);
       }
       else {
         if (IS_NCCLASS_NOT(cc)) {
-          BITSET_CLEAR_BIT(bs, *to);
+          BITSET_CLEAR_BIT(cc->bs, *to);
         }
         else
-          BITSET_SET_BIT(bs, *to);
+          BITSET_SET_BIT(cc->bs, *to);
       }
     }
 #endif /* CASE_FOLD_IS_APPLIED_INSIDE_NEGATIVE_CCLASS */
@@ -7818,34 +7847,65 @@ i_apply_case_fold(OnigCodePoint from, OnigCodePoint to[], int to_len, void* arg)
   else {
     int r, i, len;
     UChar buf[ONIGENC_CODE_TO_MBC_MAXLEN];
-    Node *snode = NULL_NODE;
 
     if (onig_is_code_in_cc(env->enc, from, cc)
 #ifdef CASE_FOLD_IS_APPLIED_INSIDE_NEGATIVE_CCLASS
         && !IS_NCCLASS_NOT(cc)
 #endif
         ) {
+      int n, j, m, index;
+      Node* list_node;
+      Node* ns[3];
+
+      n = 0;
       for (i = 0; i < to_len; i++) {
-        len = ONIGENC_CODE_TO_MBC(env->enc, to[i], buf);
-        if (i == 0) {
-          snode = onig_node_new_str(buf, buf + len);
-          CHECK_NULL_RETURN_MEMERR(snode);
-
-          /* char-class expanded multi-char only
-             compare with string folded at match time. */
-          NODE_STRING_SET_AMBIG(snode);
+        OnigCodePoint code;
+        Node* csnode;
+        CClassNode* cs_cc;
+
+        index = onigenc_unicode_fold1_key(&to[i]);
+        if (index >= 0) {
+          csnode = node_new_cclass();
+          cs_cc = CCLASS_(csnode);
+          if (IS_NULL(csnode)) {
+          err_free_ns:
+            for (j = 0; j < n; j++) onig_node_free(ns[j]);
+            return ONIGERR_MEMORY;
+          }
+          m = FOLDS1_UNFOLDS_NUM(index);
+          for (j = 0; j < m; j++) {
+            code = FOLDS1_UNFOLDS(index)[j];
+            ADD_CODE_INTO_CC(cs_cc, code, env->enc);
+          }
+          ADD_CODE_INTO_CC(cs_cc, to[i], env->enc);
+          ns[n++] = csnode;
         }
         else {
-          r = onig_node_str_cat(snode, buf, buf + len);
-          if (r < 0) {
-            onig_node_free(snode);
-            return r;
+          len = ONIGENC_CODE_TO_MBC(env->enc, to[i], buf);
+          if (n == 0 || NODE_TYPE(ns[n-1]) != NODE_STRING) {
+            csnode = onig_node_new_str(buf, buf + len);
+            if (IS_NULL(csnode)) goto err_free_ns;
+
+            NODE_STRING_SET_CASE_EXPANDED(csnode);
+            ns[n++] = csnode;
+          }
+          else {
+            r = onig_node_str_cat(ns[n-1], buf, buf + len);
+            if (r < 0) goto err_free_ns;
           }
         }
       }
 
-      *(iarg->ptail) = onig_node_new_alt(snode, NULL_NODE);
-      CHECK_NULL_RETURN_MEMERR(*(iarg->ptail));
+      if (n == 1)
+        list_node = ns[0];
+      else
+        list_node = make_list(n, ns);
+
+      *(iarg->ptail) = onig_node_new_alt(list_node, NULL_NODE);
+      if (IS_NULL(*(iarg->ptail))) {
+        onig_node_free(list_node);
+        return ONIGERR_MEMORY;
+      }
       iarg->ptail = &(NODE_CDR((*(iarg->ptail))));
     }
   }
@@ -7901,7 +7961,7 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
       env->options = BAG_(*np)->o.options;
       r = fetch_token(tok, src, end, env);
       if (r < 0) return r;
-      r = parse_subexp(&target, tok, term, src, end, env, 0);
+      r = parse_alts(&target, tok, term, src, end, env, FALSE);
       env->options = prev;
       if (r < 0) {
         onig_node_free(target);
@@ -7916,7 +7976,7 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
     if (! IS_SYNTAX_BV(env->syntax, ONIG_SYN_ALLOW_UNMATCHED_CLOSE_SUBEXP))
       return ONIGERR_UNMATCHED_CLOSE_PARENTHESIS;
 
-    if (tok->escaped) goto tk_raw_byte;
+    if (tok->escaped) goto tk_crude_byte;
     else goto tk_byte;
     break;
 
@@ -7941,36 +8001,36 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
     }
     break;
 
-  case TK_RAW_BYTE:
-  tk_raw_byte:
+  case TK_CRUDE_BYTE:
+  tk_crude_byte:
     {
-      *np = node_new_str_raw_char((UChar )tok->u.c);
+      *np = node_new_str_crude_char(tok->u.byte);
       CHECK_NULL_RETURN_MEMERR(*np);
       len = 1;
       while (1) {
         if (len >= ONIGENC_MBC_MINLEN(env->enc)) {
           if (len == enclen(env->enc, STR_(*np)->s)) {
             r = fetch_token(tok, src, end, env);
-            goto tk_raw_byte_end;
+            goto tk_crude_byte_end;
           }
         }
 
         r = fetch_token(tok, src, end, env);
         if (r < 0) return r;
-        if (r != TK_RAW_BYTE)
+        if (r != TK_CRUDE_BYTE)
           return ONIGERR_TOO_SHORT_MULTI_BYTE_STRING;
 
-        r = node_str_cat_char(*np, (UChar )tok->u.c);
+        r = node_str_cat_char(*np, tok->u.byte);
         if (r < 0) return r;
 
         len++;
       }
 
-    tk_raw_byte_end:
+    tk_crude_byte_end:
       if (! ONIGENC_IS_VALID_MBC_STRING(env->enc, STR_(*np)->s, STR_(*np)->end))
         return ONIGERR_INVALID_WIDE_CHAR_VALUE;
 
-      NODE_STRING_CLEAR_RAW(*np);
+      NODE_STRING_CLEAR_CRUDE(*np);
       goto string_end;
     }
     break;
@@ -7981,7 +8041,7 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
       len = ONIGENC_CODE_TO_MBC(env->enc, tok->u.code, buf);
       if (len < 0) return len;
 #ifdef NUMBERED_CHAR_IS_NOT_CASE_AMBIG
-      *np = node_new_str_raw(buf, buf + len);
+      *np = node_new_str_crude(buf, buf + len);
 #else
       *np = node_new_str(buf, buf + len);
 #endif
@@ -8024,7 +8084,7 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
           *np = node_new_cclass();
           CHECK_NULL_RETURN_MEMERR(*np);
           cc = CCLASS_(*np);
-          add_ctype_to_cc(cc, tok->u.prop.ctype, 0, env);
+          add_ctype_to_cc(cc, tok->u.prop.ctype, FALSE, env);
           if (tok->u.prop.not != 0) NCCLASS_SET_NOT(cc);
         }
         break;
@@ -8041,11 +8101,11 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
     if (r != 0) return r;
     break;
 
-  case TK_CC_OPEN:
+  case TK_OPEN_CC:
     {
       CClassNode* cc;
 
-      r = parse_char_class(np, tok, src, end, env);
+      r = parse_cc(np, tok, src, end, env);
       if (r != 0) return r;
 
       cc = CCLASS_(*np);
@@ -8083,7 +8143,7 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
   case TK_ANYCHAR_ANYTIME:
     *np = node_new_anychar();
     CHECK_NULL_RETURN_MEMERR(*np);
-    qn = node_new_quantifier(0, INFINITE_REPEAT, 0);
+    qn = node_new_quantifier(0, INFINITE_REPEAT, FALSE);
     CHECK_NULL_RETURN_MEMERR(qn);
     NODE_BODY(qn) = *np;
     *np = qn;
@@ -8186,9 +8246,7 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
       if (is_invalid_quantifier_target(*tp))
         return ONIGERR_TARGET_OF_REPEAT_OPERATOR_INVALID;
 
-      parse_depth++;
-      if (parse_depth > ParseDepthLimit)
-        return ONIGERR_PARSE_DEPTH_LIMIT_OVER;
+      INC_PARSE_DEPTH(parse_depth);
 
       qn = node_new_quantifier(tok->u.repeat.lower, tok->u.repeat.upper,
                                r == TK_INTERVAL);
@@ -8201,9 +8259,10 @@ parse_exp(Node** np, PToken* tok, int term, UChar** src, UChar* end,
       else {
         target = *tp;
       }
-      r = set_quantifier(qn, target, group, env);
+      r = assign_quantifier_body(qn, target, group, env);
       if (r < 0) {
         onig_node_free(qn);
+        *tp = NULL_NODE;
         return r;
       }
 
@@ -8256,6 +8315,8 @@ parse_branch(Node** top, PToken* tok, int term, UChar** src, UChar* end,
   Node *node, **headp;
 
   *top = NULL;
+  INC_PARSE_DEPTH(env->parse_depth);
+
   r = parse_exp(&node, tok, term, src, end, env, group_head);
   if (r < 0) {
     onig_node_free(node);
@@ -8266,7 +8327,7 @@ parse_branch(Node** top, PToken* tok, int term, UChar** src, UChar* end,
     *top = node;
   }
   else {
-    *top  = node_new_list(node, NULL);
+    *top = node_new_list(node, NULL);
     if (IS_NULL(*top)) {
       onig_node_free(node);
       return ONIGERR_MEMORY;
@@ -8274,7 +8335,7 @@ parse_branch(Node** top, PToken* tok, int term, UChar** src, UChar* end,
 
     headp = &(NODE_CDR(*top));
     while (r != TK_EOT && r != term && r != TK_ALT) {
-      r = parse_exp(&node, tok, term, src, end, env, 0);
+      r = parse_exp(&node, tok, term, src, end, env, FALSE);
       if (r < 0) {
         onig_node_free(node);
         return r;
@@ -8292,21 +8353,20 @@ parse_branch(Node** top, PToken* tok, int term, UChar** src, UChar* end,
     }
   }
 
+  DEC_PARSE_DEPTH(env->parse_depth);
   return r;
 }
 
 /* term_tok: TK_EOT or TK_SUBEXP_CLOSE */
 static int
-parse_subexp(Node** top, PToken* tok, int term, UChar** src, UChar* end,
-             ScanEnv* env, int group_head)
+parse_alts(Node** top, PToken* tok, int term, UChar** src, UChar* end,
+           ScanEnv* env, int group_head)
 {
   int r;
   Node *node, **headp;
 
   *top = NULL;
-  env->parse_depth++;
-  if (env->parse_depth > ParseDepthLimit)
-    return ONIGERR_PARSE_DEPTH_LIMIT_OVER;
+  INC_PARSE_DEPTH(env->parse_depth);
 
   r = parse_branch(&node, tok, term, src, end, env, group_head);
   if (r < 0) {
@@ -8328,7 +8388,7 @@ parse_subexp(Node** top, PToken* tok, int term, UChar** src, UChar* end,
     while (r == TK_ALT) {
       r = fetch_token(tok, src, end, env);
       if (r < 0) return r;
-      r = parse_branch(&node, tok, term, src, end, env, 0);
+      r = parse_branch(&node, tok, term, src, end, env, FALSE);
       if (r < 0) {
         onig_node_free(node);
         return r;
@@ -8355,7 +8415,7 @@ parse_subexp(Node** top, PToken* tok, int term, UChar** src, UChar* end,
       return ONIGERR_PARSER_BUG;
   }
 
-  env->parse_depth--;
+  DEC_PARSE_DEPTH(env->parse_depth);
   return r;
 }
 
@@ -8367,7 +8427,7 @@ parse_regexp(Node** top, UChar** src, UChar* end, ScanEnv* env)
 
   r = fetch_token(&tok, src, end, env);
   if (r < 0) return r;
-  r = parse_subexp(top, &tok, TK_EOT, src, end, env, 0);
+  r = parse_alts(top, &tok, TK_EOT, src, end, env, FALSE);
   if (r < 0) return r;
 
   return 0;
diff --git a/src/regparse.h b/src/regparse.h
index 231f7b5..1525ccb 100644
--- a/src/regparse.h
+++ b/src/regparse.h
@@ -4,7 +4,7 @@
   regparse.h -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,7 +32,7 @@
 #include "regint.h"
 
 #define NODE_STRING_MARGIN         16
-#define NODE_STRING_BUF_SIZE       24  /* sizeof(CClassNode) - sizeof(int)*4 */
+#define NODE_STRING_BUF_SIZE       20  /* sizeof(CClassNode) - sizeof(int)*4 */
 #define NODE_BACKREFS_SIZE          6
 
 /* node type */
@@ -73,20 +73,25 @@ enum BodyEmptyType {
   BODY_IS_EMPTY_POSSIBILITY_REC = 3
 };
 
+struct _Node;
+
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
 
   UChar* s;
   UChar* end;
   unsigned int flag;
-  int    capacity;    /* (allocated size - 1) or 0: use buf[] */
   UChar  buf[NODE_STRING_BUF_SIZE];
+  int    capacity;    /* (allocated size - 1) or 0: use buf[] */
+  int    case_min_len;
 } StrNode;
 
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
 
   unsigned int flags;
   BitSet bs;
@@ -96,6 +101,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
   struct _Node* body;
 
   int lower;
@@ -104,12 +110,13 @@ typedef struct {
   enum BodyEmptyType emptiness;
   struct _Node* head_exact;
   struct _Node* next_head_exact;
-  int is_refered;     /* include called node. don't eliminate even if {0} */
+  int include_referred;   /* include called node. don't eliminate even if {0} */
 } QuantNode;
 
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
   struct _Node* body;
 
   enum BagType type;
@@ -152,6 +159,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
   struct _Node* body; /* to BagNode : BAG_MEMORY */
 
   int     by_number;
@@ -166,6 +174,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
 
   int  back_num;
   int  back_static[NODE_BACKREFS_SIZE];
@@ -176,6 +185,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
   struct _Node* body;
 
   int type;
@@ -186,6 +196,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
 
   struct _Node* car;
   struct _Node* cdr;
@@ -194,6 +205,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
 
   int ctype;
   int not;
@@ -204,6 +216,7 @@ typedef struct {
 typedef struct {
   NodeType node_type;
   int status;
+  struct _Node* parent;
 
   enum GimmickType type;
   int  detail_type;
@@ -216,6 +229,7 @@ typedef struct _Node {
     struct {
       NodeType node_type;
       int status;
+      struct _Node* parent;
       struct _Node* body;
     } base;
 
@@ -280,26 +294,21 @@ typedef struct _Node {
 #define ANCR_ANYCHAR_INF_MASK  (ANCR_ANYCHAR_INF | ANCR_ANYCHAR_INF_ML)
 #define ANCR_END_BUF_MASK      (ANCR_END_BUF | ANCR_SEMI_END_BUF)
 
-#define NODE_STRING_RAW                (1<<0) /* by backslashed number */
-#define NODE_STRING_AMBIG              (1<<1)
-#define NODE_STRING_GOOD_AMBIG         (1<<2)
-#define NODE_STRING_DONT_GET_OPT_INFO  (1<<3)
+#define NODE_STRING_CRUDE              (1<<0)
+#define NODE_STRING_CASE_EXPANDED      (1<<1)
+#define NODE_STRING_CASE_FOLD_MATCH    (1<<2)
 
 #define NODE_STRING_LEN(node)            (int )((node)->u.str.end - (node)->u.str.s)
-#define NODE_STRING_SET_RAW(node)        (node)->u.str.flag |= NODE_STRING_RAW
-#define NODE_STRING_CLEAR_RAW(node)      (node)->u.str.flag &= ~NODE_STRING_RAW
-#define NODE_STRING_SET_AMBIG(node)      (node)->u.str.flag |= NODE_STRING_AMBIG
-#define NODE_STRING_SET_GOOD_AMBIG(node) (node)->u.str.flag |= NODE_STRING_GOOD_AMBIG
-#define NODE_STRING_SET_DONT_GET_OPT_INFO(node) \
-  (node)->u.str.flag |= NODE_STRING_DONT_GET_OPT_INFO
-#define NODE_STRING_IS_RAW(node) \
-  (((node)->u.str.flag & NODE_STRING_RAW) != 0)
-#define NODE_STRING_IS_AMBIG(node) \
-  (((node)->u.str.flag & NODE_STRING_AMBIG) != 0)
-#define NODE_STRING_IS_GOOD_AMBIG(node) \
-  (((node)->u.str.flag & NODE_STRING_GOOD_AMBIG) != 0)
-#define NODE_STRING_IS_DONT_GET_OPT_INFO(node) \
-  (((node)->u.str.flag & NODE_STRING_DONT_GET_OPT_INFO) != 0)
+#define NODE_STRING_SET_CRUDE(node)         (node)->u.str.flag |= NODE_STRING_CRUDE
+#define NODE_STRING_CLEAR_CRUDE(node)       (node)->u.str.flag &= ~NODE_STRING_CRUDE
+#define NODE_STRING_SET_CASE_EXPANDED(node) (node)->u.str.flag |= NODE_STRING_CASE_EXPANDED
+#define NODE_STRING_SET_CASE_FOLD_MATCH(node) (node)->u.str.flag |= NODE_STRING_CASE_FOLD_MATCH
+#define NODE_STRING_IS_CRUDE(node) \
+  (((node)->u.str.flag & NODE_STRING_CRUDE) != 0)
+#define NODE_STRING_IS_CASE_EXPANDED(node) \
+  (((node)->u.str.flag & NODE_STRING_CASE_EXPANDED) != 0)
+#define NODE_STRING_IS_CASE_FOLD_MATCH(node) \
+  (((node)->u.str.flag & NODE_STRING_CASE_FOLD_MATCH) != 0)
 
 #define BACKREFS_P(br) \
   (IS_NOT_NULL((br)->back_dynamic) ? (br)->back_dynamic : (br)->back_static)
@@ -326,6 +335,7 @@ typedef struct _Node {
 #define NODE_ST_FIXED_OPTION          (1<<18)
 #define NODE_ST_PROHIBIT_RECURSION    (1<<19)
 #define NODE_ST_SUPER                 (1<<20)
+#define NODE_ST_EMPTY_STATUS_CHECK    (1<<21)
 
 
 #define NODE_STATUS(node)           (((Node* )node)->u.base.status)
@@ -355,7 +365,10 @@ typedef struct _Node {
     ((NODE_STATUS(node) & NODE_ST_PROHIBIT_RECURSION) != 0)
 #define NODE_IS_STRICT_REAL_REPEAT(node) \
     ((NODE_STATUS(node) & NODE_ST_STRICT_REAL_REPEAT) != 0)
+#define NODE_IS_EMPTY_STATUS_CHECK(node) \
+    ((NODE_STATUS(node) & NODE_ST_EMPTY_STATUS_CHECK) != 0)
 
+#define NODE_PARENT(node)         ((node)->u.base.parent)
 #define NODE_BODY(node)           ((node)->u.base.body)
 #define NODE_QUANT_BODY(node)     ((node)->body)
 #define NODE_BAG_BODY(node)       ((node)->body)
@@ -368,11 +381,8 @@ typedef struct _Node {
     (senv)->mem_env_dynamic : (senv)->mem_env_static)
 
 typedef struct {
-  Node* node;
-#if 0
-  int in;
-  int recursion;
-#endif
+  Node* mem_node;
+  Node* empty_repeat_node;
 } MemEnv;
 
 typedef struct {
@@ -384,9 +394,8 @@ typedef struct {
   OnigCaseFoldType case_fold_flag;
   OnigEncoding     enc;
   OnigSyntaxType*  syntax;
-  MemStatusType    capture_history;
-  MemStatusType    bt_mem_start;
-  MemStatusType    bt_mem_end;
+  MemStatusType    cap_history;
+  MemStatusType    backtrack_mem; /* backtrack/recursion */
   MemStatusType    backrefed_mem;
   UChar*           pattern;
   UChar*           pattern_end;
@@ -404,7 +413,10 @@ typedef struct {
   MemEnv           mem_env_static[SCANENV_MEMENV_SIZE];
   MemEnv*          mem_env_dynamic;
   unsigned int     parse_depth;
-
+#ifdef ONIG_DEBUG_PARSE
+  unsigned int     max_parse_depth;
+#endif
+  int backref_num;
   int keep_num;
   int save_num;
   int save_alloc_num;
@@ -425,9 +437,7 @@ extern int    onig_renumber_name_table P_((regex_t* reg, GroupNumRemap* map));
 extern int    onig_strncmp P_((const UChar* s1, const UChar* s2, int n));
 extern void   onig_strcpy P_((UChar* dest, const UChar* src, const UChar* end));
 extern void   onig_scan_env_set_error_string P_((ScanEnv* env, int ecode, UChar* arg, UChar* arg_end));
-extern int    onig_scan_unsigned_number P_((UChar** src, const UChar* end, OnigEncoding enc));
-extern void   onig_reduce_nested_quantifier P_((Node* pnode, Node* cnode));
-extern void   onig_node_conv_to_str_node P_((Node* node, int raw));
+extern int    onig_reduce_nested_quantifier P_((Node* pnode));
 extern int    onig_node_str_cat P_((Node* node, const UChar* s, const UChar* end));
 extern int    onig_node_str_set P_((Node* node, const UChar* s, const UChar* end));
 extern void   onig_node_free P_((Node* node));
@@ -435,13 +445,13 @@ extern Node*  onig_node_new_bag P_((enum BagType type));
 extern Node*  onig_node_new_anchor P_((int type, int ascii_mode));
 extern Node*  onig_node_new_str P_((const UChar* s, const UChar* end));
 extern Node*  onig_node_new_list P_((Node* left, Node* right));
-extern Node*  onig_node_list_add P_((Node* list, Node* x));
 extern Node*  onig_node_new_alt P_((Node* left, Node* right));
 extern void   onig_node_str_clear P_((Node* node));
 extern int    onig_names_free P_((regex_t* reg));
 extern int    onig_parse_tree P_((Node** root, const UChar* pattern, const UChar* end, regex_t* reg, ScanEnv* env));
 extern int    onig_free_shared_cclass_table P_((void));
 extern int    onig_is_code_in_cc P_((OnigEncoding enc, OnigCodePoint code, CClassNode* cc));
+extern int    onig_new_cclass_with_code_list(Node** rnode, OnigEncoding enc, int n, OnigCodePoint codes[]);
 extern OnigLen onig_get_tiny_min_len(Node* node, unsigned int inhibit_node_types, int* invalid_node);
 
 #ifdef USE_CALLOUT
diff --git a/src/regposerr.c b/src/regposerr.c
index e389531..e1747c5 100644
--- a/src/regposerr.c
+++ b/src/regposerr.c
@@ -2,7 +2,7 @@
   regposerr.c - Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/regposix.c b/src/regposix.c
index 09e16ac..b3e78ff 100644
--- a/src/regposix.c
+++ b/src/regposix.c
@@ -2,7 +2,7 @@
   regposix.c - Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/regsyntax.c b/src/regsyntax.c
index d4420cc..513c7f7 100644
--- a/src/regsyntax.c
+++ b/src/regsyntax.c
@@ -2,7 +2,7 @@
   regsyntax.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/regtrav.c b/src/regtrav.c
index 58a17f5..8307695 100644
--- a/src/regtrav.c
+++ b/src/regtrav.c
@@ -2,7 +2,7 @@
   regtrav.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2004  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/regversion.c b/src/regversion.c
index 594a52c..de993d3 100644
--- a/src/regversion.c
+++ b/src/regversion.c
@@ -2,7 +2,7 @@
   regversion.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/src/sjis.c b/src/sjis.c
index 4f90b72..1fd92d9 100644
--- a/src/sjis.c
+++ b/src/sjis.c
@@ -2,7 +2,7 @@
   sjis.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -149,10 +149,6 @@ code_to_mbc(OnigCodePoint code, UChar *buf)
   if ((code & 0xff00) != 0) *p++ = (UChar )(((code >>  8) & 0xff));
   *p++ = (UChar )(code & 0xff);
 
-#if 0
-  if (enclen(ONIG_ENCODING_SJIS, buf) != (p - buf))
-    return REGERR_INVALID_CODE_POINT_VALUE;
-#endif
   return (int )(p - buf);
 }
 
@@ -179,31 +175,6 @@ mbc_case_fold(OnigCaseFoldType flag ARG_UNUSED,
   }
 }
 
-#if 0
-static int
-is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  return onigenc_mbn_is_mbc_ambiguous(ONIG_ENCODING_SJIS, flag, pp, end);
-
-}
-#endif
-
-#if 0
-static int
-is_code_ctype(OnigCodePoint code, unsigned int ctype)
-{
-  if (code < 128)
-    return ONIGENC_IS_ASCII_CODE_CTYPE(code, ctype);
-  else {
-    if (CTYPE_IS_WORD_GRAPH_PRINT(ctype)) {
-      return (code_to_mbclen(code) > 1 ? TRUE : FALSE);
-    }
-  }
-
-  return FALSE;
-}
-#endif
-
 static UChar*
 left_adjust_char_head(const UChar* start, const UChar* s)
 {
diff --git a/src/sjis_prop.c b/src/sjis_prop.c
index 3a88a38..e33fbb2 100644
--- a/src/sjis_prop.c
+++ b/src/sjis_prop.c
@@ -1,5 +1,5 @@
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -pt -T -L ANSI-C -N onigenc_sjis_lookup_property_name --output-file gperf2.tmp sjis_prop.gperf  */
+/* Command-line: gperf -pt -T -L ANSI-C -N onigenc_sjis_lookup_property_name --output-file gperf2.tmp sjis_prop.gperf  */
 /* Computed positions: -k'1,3' */
 
 #if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
diff --git a/src/unicode.c b/src/unicode.c
index 5820319..474436a 100644
--- a/src/unicode.c
+++ b/src/unicode.c
@@ -2,7 +2,7 @@
   unicode.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -356,16 +356,15 @@ onigenc_unicode_get_case_fold_codes_by_str(OnigEncoding enc,
         for (fn = 0; fn < 2; fn++) {
           int index;
           cs[fn][0] = FOLDS2_FOLD(buk->index)[fn];
+          ncs[fn] = 1;
           index = onigenc_unicode_fold1_key(&cs[fn][0]);
           if (index >= 0) {
             int m = FOLDS1_UNFOLDS_NUM(index);
             for (i = 0; i < m; i++) {
               cs[fn][i+1] = FOLDS1_UNFOLDS(index)[i];
             }
-            ncs[fn] = m + 1;
+            ncs[fn] += m;
           }
-          else
-            ncs[fn] = 1;
         }
 
         for (i = 0; i < ncs[0]; i++) {
@@ -393,16 +392,15 @@ onigenc_unicode_get_case_fold_codes_by_str(OnigEncoding enc,
         for (fn = 0; fn < 3; fn++) {
           int index;
           cs[fn][0] = FOLDS3_FOLD(buk->index)[fn];
+          ncs[fn] = 1;
           index = onigenc_unicode_fold1_key(&cs[fn][0]);
           if (index >= 0) {
             int m = FOLDS1_UNFOLDS_NUM(index);
             for (i = 0; i < m; i++) {
               cs[fn][i+1] = FOLDS1_UNFOLDS(index)[i];
             }
-            ncs[fn] = m + 1;
+            ncs[fn] += m;
           }
-          else
-            ncs[fn] = 1;
         }
 
         for (i = 0; i < ncs[0]; i++) {
diff --git a/src/unicode_egcb_data.c b/src/unicode_egcb_data.c
index 6a74c77..3c49422 100644
--- a/src/unicode_egcb_data.c
+++ b/src/unicode_egcb_data.c
@@ -1,6 +1,6 @@
 /* unicode_egcb_data.c: Generated by make_unicode_egcb_data.py. */
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,7 +25,7 @@
  * SUCH DAMAGE.
  */
 
-#define GRAPHEME_BREAK_PROPERTY_VERSION  12_1_0
+#define GRAPHEME_BREAK_PROPERTY_VERSION  120100
 
 /*
 CR
diff --git a/src/unicode_fold1_key.c b/src/unicode_fold1_key.c
index b84b528..171a0fa 100644
--- a/src/unicode_fold1_key.c
+++ b/src/unicode_fold1_key.c
@@ -1,7 +1,7 @@
 /* This file was converted by gperf_fold_key_conv.py
       from gperf output file. */
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1 -N onigenc_unicode_fold1_key unicode_fold1_key.gperf  */
+/* Command-line: gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1 -N onigenc_unicode_fold1_key unicode_fold1_key.gperf  */
 /* Computed positions: -k'1-3' */
 
 
@@ -9,7 +9,7 @@
 /* This gperf source file was generated by make_unicode_fold_data.py */
 
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -2983,7 +2983,7 @@ onigenc_unicode_fold1_key(OnigCodePoint codes[])
       4026
     };
 
-  if (0 == 0)
+
     {
       int key = hash(codes);
 
diff --git a/src/unicode_fold2_key.c b/src/unicode_fold2_key.c
index 2310f0a..c39b19d 100644
--- a/src/unicode_fold2_key.c
+++ b/src/unicode_fold2_key.c
@@ -1,7 +1,7 @@
 /* This file was converted by gperf_fold_key_conv.py
       from gperf output file. */
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1 -N onigenc_unicode_fold2_key unicode_fold2_key.gperf  */
+/* Command-line: gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1 -N onigenc_unicode_fold2_key unicode_fold2_key.gperf  */
 /* Computed positions: -k'3,6' */
 
 
@@ -9,7 +9,7 @@
 /* This gperf source file was generated by make_unicode_fold_data.py */
 
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -211,7 +211,7 @@ onigenc_unicode_fold2_key(OnigCodePoint codes[])
       129
     };
 
-  if (0 == 0)
+
     {
       int key = hash(codes);
 
diff --git a/src/unicode_fold3_key.c b/src/unicode_fold3_key.c
index 0e02a62..295c447 100644
--- a/src/unicode_fold3_key.c
+++ b/src/unicode_fold3_key.c
@@ -1,7 +1,7 @@
 /* This file was converted by gperf_fold_key_conv.py
       from gperf output file. */
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1 -N onigenc_unicode_fold3_key unicode_fold3_key.gperf  */
+/* Command-line: gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1 -N onigenc_unicode_fold3_key unicode_fold3_key.gperf  */
 /* Computed positions: -k'3,6,9' */
 
 
@@ -9,7 +9,7 @@
 /* This gperf source file was generated by make_unicode_fold_data.py */
 
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -121,7 +121,7 @@ onigenc_unicode_fold3_key(OnigCodePoint codes[])
       0
     };
 
-  if (0 == 0)
+
     {
       int key = hash(codes);
 
diff --git a/src/unicode_fold_data.c b/src/unicode_fold_data.c
index 0dbf9ae..68694b0 100644
--- a/src/unicode_fold_data.c
+++ b/src/unicode_fold_data.c
@@ -1,7 +1,7 @@
 /* This file was generated by make_unicode_fold_data.py. */
 #include "regenc.h"
 
-#define UNICODE_CASEFOLD_VERSION  12_1_0
+#define UNICODE_CASEFOLD_VERSION  120100
 
 
 OnigCodePoint OnigUnicodeFolds1[] = {
diff --git a/src/unicode_property_data.c b/src/unicode_property_data.c
index 5c1c8a9..0083dd6 100644
--- a/src/unicode_property_data.c
+++ b/src/unicode_property_data.c
@@ -1,5 +1,5 @@
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -T -C -c -t -j1 -L ANSI-C --ignore-case --pic -Q unicode_prop_name_pool -N unicode_lookup_property_name --output-file gperf1.tmp unicode_property_data.gperf  */
+/* Command-line: gperf -T -C -c -t -j1 -L ANSI-C --ignore-case --pic -Q unicode_prop_name_pool -N unicode_lookup_property_name --output-file gperf1.tmp unicode_property_data.gperf  */
 /* Computed positions: -k'1-3,5-6,12,16,$' */
 
 #if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
@@ -29580,7 +29580,8 @@ unicode_lookup_property_name (register const char *str, register size_t len)
 
 
 
-#define UNICODE_PROPERTY_VERSION  12_1_0
+#define UNICODE_PROPERTY_VERSION  120100
+#define UNICODE_EMOJI_VERSION     1201
 
 #define PROPERTY_NAME_MAX_SIZE  59
 #define CODE_RANGES_NUM         568
diff --git a/src/unicode_property_data_posix.c b/src/unicode_property_data_posix.c
index eddc108..e299e85 100644
--- a/src/unicode_property_data_posix.c
+++ b/src/unicode_property_data_posix.c
@@ -1,5 +1,5 @@
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -T -C -c -t -j1 -L ANSI-C --ignore-case --pic -Q unicode_prop_name_pool -N unicode_lookup_property_name --output-file gperf2.tmp unicode_property_data_posix.gperf  */
+/* Command-line: gperf -T -C -c -t -j1 -L ANSI-C --ignore-case --pic -Q unicode_prop_name_pool -N unicode_lookup_property_name --output-file gperf2.tmp unicode_property_data_posix.gperf  */
 /* Computed positions: -k'1,3' */
 
 #if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
diff --git a/src/unicode_unfold_key.c b/src/unicode_unfold_key.c
index b2228e0..51a037b 100644
--- a/src/unicode_unfold_key.c
+++ b/src/unicode_unfold_key.c
@@ -1,7 +1,7 @@
 /* This file was converted by gperf_unfold_key_conv.py
       from gperf output file. */
 /* ANSI-C code produced by gperf version 3.1 */
-/* Command-line: /usr/local/bin/gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1,0 -N onigenc_unicode_unfold_key unicode_unfold_key.gperf  */
+/* Command-line: gperf -n -C -T -c -t -j1 -L ANSI-C -F,-1,0 -N onigenc_unicode_unfold_key unicode_unfold_key.gperf  */
 /* Computed positions: -k'1-3' */
 
 
@@ -9,7 +9,7 @@
 /* This gperf source file was generated by make_unicode_fold_data.py */
 
 /*-
- * Copyright (c) 2017-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2017-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -3288,7 +3288,7 @@ onigenc_unicode_unfold_key(OnigCodePoint code)
       {0x1e907, 4005, 1}
     };
 
-  if (0 == 0)
+
     {
       int key = hash(&code);
 
diff --git a/src/unicode_wb_data.c b/src/unicode_wb_data.c
index 7778157..8e1a267 100644
--- a/src/unicode_wb_data.c
+++ b/src/unicode_wb_data.c
@@ -1,6 +1,6 @@
 /* unicode_wb_data.c: Generated by make_unicode_wb_data.py. */
 /*-
- * Copyright (c) 2019  K.Kosako  <kkosako0 AT gmail DOT com>
+ * Copyright (c) 2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,7 +25,7 @@
  * SUCH DAMAGE.
  */
 
-#define WORD_BREAK_PROPERTY_VERSION  12_1_0
+#define WORD_BREAK_PROPERTY_VERSION  120100
 
 /*
 ALetter
diff --git a/src/utf16_be.c b/src/utf16_be.c
index b66d868..d99af71 100644
--- a/src/utf16_be.c
+++ b/src/utf16_be.c
@@ -2,7 +2,7 @@
   utf16_be.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -227,39 +227,6 @@ utf16be_mbc_case_fold(OnigCaseFoldType flag,
                                          pp, end, fold);
 }
 
-#if 0
-static int
-utf16be_is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  const UChar* p = *pp;
-
-  (*pp) += EncLen_UTF16[*p];
-
-  if (*p == 0) {
-    int c, v;
-
-    p++;
-    if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-      return TRUE;
-    }
-
-    c = *p;
-    v = ONIGENC_IS_UNICODE_ISO_8859_1_BIT_CTYPE(c, (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-
-    if ((v | BIT_CTYPE_LOWER) != 0) {
-      /* 0xaa, 0xb5, 0xba are lower case letter, but can't convert. */
-      if (c >= 0xaa && c <= 0xba)
-        return FALSE;
-      else
-        return TRUE;
-    }
-    return (v != 0 ? TRUE : FALSE);
-  }
-
-  return FALSE;
-}
-#endif
-
 static UChar*
 utf16be_left_adjust_char_head(const UChar* start, const UChar* s)
 {
diff --git a/src/utf16_le.c b/src/utf16_le.c
index cdc74b0..c6edd94 100644
--- a/src/utf16_le.c
+++ b/src/utf16_le.c
@@ -2,7 +2,7 @@
   utf16_le.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -227,39 +227,6 @@ utf16le_mbc_case_fold(OnigCaseFoldType flag,
                                          fold);
 }
 
-#if 0
-static int
-utf16le_is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp,
-                         const UChar* end)
-{
-  const UChar* p = *pp;
-
-  (*pp) += EncLen_UTF16[*(p+1)];
-
-  if (*(p+1) == 0) {
-    int c, v;
-
-    if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-      return TRUE;
-    }
-
-    c = *p;
-    v = ONIGENC_IS_UNICODE_ISO_8859_1_BIT_CTYPE(c,
-                       (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-    if ((v | BIT_CTYPE_LOWER) != 0) {
-      /* 0xaa, 0xb5, 0xba are lower case letter, but can't convert. */
-      if (c >= 0xaa && c <= 0xba)
-        return FALSE;
-      else
-        return TRUE;
-    }
-    return (v != 0 ? TRUE : FALSE);
-  }
-
-  return FALSE;
-}
-#endif
-
 static UChar*
 utf16le_left_adjust_char_head(const UChar* start, const UChar* s)
 {
diff --git a/src/utf32_be.c b/src/utf32_be.c
index dd17d3b..67e50a2 100644
--- a/src/utf32_be.c
+++ b/src/utf32_be.c
@@ -2,7 +2,7 @@
   utf32_be.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -119,39 +119,6 @@ utf32be_mbc_case_fold(OnigCaseFoldType flag,
                                          fold);
 }
 
-#if 0
-static int
-utf32be_is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  const UChar* p = *pp;
-
-  (*pp) += 4;
-
-  if (*(p+2) == 0 && *(p+1) == 0 && *p == 0) {
-    int c, v;
-
-    p += 3;
-    if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-      return TRUE;
-    }
-
-    c = *p;
-    v = ONIGENC_IS_UNICODE_ISO_8859_1_BIT_CTYPE(c,
-                       (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-    if ((v | BIT_CTYPE_LOWER) != 0) {
-      /* 0xaa, 0xb5, 0xba are lower case letter, but can't convert. */
-      if (c >= 0xaa && c <= 0xba)
-        return FALSE;
-      else
-        return TRUE;
-    }
-    return (v != 0 ? TRUE : FALSE);
-  }
-
-  return FALSE;
-}
-#endif
-
 static UChar*
 utf32be_left_adjust_char_head(const UChar* start, const UChar* s)
 {
diff --git a/src/utf32_le.c b/src/utf32_le.c
index d9fe3c6..2ae2275 100644
--- a/src/utf32_le.c
+++ b/src/utf32_le.c
@@ -2,7 +2,7 @@
   utf32_le.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2018  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -120,38 +120,6 @@ utf32le_mbc_case_fold(OnigCaseFoldType flag,
                                          fold);
 }
 
-#if 0
-static int
-utf32le_is_mbc_ambiguous(OnigCaseFoldType flag, const UChar** pp, const UChar* end)
-{
-  const UChar* p = *pp;
-
-  (*pp) += 4;
-
-  if (*(p+1) == 0 && *(p+2) == 0 && *(p+3) == 0) {
-    int c, v;
-
-    if (*p == 0xdf && (flag & INTERNAL_ONIGENC_CASE_FOLD_MULTI_CHAR) != 0) {
-      return TRUE;
-    }
-
-    c = *p;
-    v = ONIGENC_IS_UNICODE_ISO_8859_1_BIT_CTYPE(c,
-                       (BIT_CTYPE_UPPER | BIT_CTYPE_LOWER));
-    if ((v | BIT_CTYPE_LOWER) != 0) {
-      /* 0xaa, 0xb5, 0xba are lower case letter, but can't convert. */
-      if (c >= 0xaa && c <= 0xba)
-        return FALSE;
-      else
-        return TRUE;
-    }
-    return (v != 0 ? TRUE : FALSE);
-  }
-
-  return FALSE;
-}
-#endif
-
 static UChar*
 utf32le_left_adjust_char_head(const UChar* start, const UChar* s)
 {
diff --git a/src/utf8.c b/src/utf8.c
index 70c1503..1178d09 100644
--- a/src/utf8.c
+++ b/src/utf8.c
@@ -2,7 +2,7 @@
   utf8.c -  Oniguruma (regular expression library)
 **********************************************************************/
 /*-
- * Copyright (c) 2002-2019  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+ * Copyright (c) 2002-2019  K.Kosako
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -97,33 +97,6 @@ is_valid_mbc_string(const UChar* p, const UChar* end)
   return TRUE;
 }
 
-#if 0
-static int
-is_mbc_newline(const UChar* p, const UChar* end)
-{
-  if (p < end) {
-    if (*p == 0x0a) return 1;
-
-#ifdef USE_UNICODE_ALL_LINE_TERMINATORS
-#ifndef USE_CRNL_AS_LINE_TERMINATOR
-    if (*p == 0x0d) return 1;
-#endif
-    if (p + 1 < end) {
-      if (*(p+1) == 0x85 && *p == 0xc2) /* U+0085 */
-        return 1;
-      if (p + 2 < end) {
-        if ((*(p+2) == 0xa8 || *(p+2) == 0xa9)
-            && *(p+1) == 0x80 && *p == 0xe2)  /* U+2028, U+2029 */
-          return 1;
-      }
-    }
-#endif
-  }
-
-  return 0;
-}
-#endif
-
 static OnigCodePoint
 mbc_to_code(const UChar* p, const UChar* end)
 {