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-rw-r--r--lib/unistr/u8-strchr.c191
1 files changed, 26 insertions, 165 deletions
diff --git a/lib/unistr/u8-strchr.c b/lib/unistr/u8-strchr.c
index dd1cb84c..3be14c79 100644
--- a/lib/unistr/u8-strchr.c
+++ b/lib/unistr/u8-strchr.c
@@ -1,5 +1,5 @@
/* Search character in UTF-8 string.
- Copyright (C) 1999, 2002, 2006-2007, 2009-2015 Free Software Foundation,
+ Copyright (C) 1999, 2002, 2006-2007, 2009-2010 Free Software Foundation,
Inc.
Written by Bruno Haible <bruno@clisp.org>, 2002.
@@ -21,8 +21,6 @@
/* Specification. */
#include "unistr.h"
-#include <string.h>
-
uint8_t *
u8_strchr (const uint8_t *s, ucs4_t uc)
{
@@ -32,209 +30,72 @@ u8_strchr (const uint8_t *s, ucs4_t uc)
{
uint8_t c0 = uc;
- if (false)
- {
- /* Unoptimized code. */
- for (;;)
- {
- uint8_t s0 = *s;
- if (s0 == c0)
- return (uint8_t *) s;
- s++;
- if (s0 == 0)
- break;
- }
- }
- else
+ for (;; s++)
{
- /* Optimized code.
- strchr() is often so well optimized, that it's worth the
- added function call. */
- return (uint8_t *) strchr ((const char *) s, c0);
+ if (*s == c0)
+ break;
+ if (*s == 0)
+ goto notfound;
}
+ return (uint8_t *) s;
}
else
- /* Loops equivalent to strstr, optimized for a specific length (2, 3, 4)
- of the needle. We use an algorithm similar to Boyer-Moore which
- is documented in lib/unistr/u8-chr.c. There is additional
- complication because we need to check after every byte for
- a NUL byte, but the idea is the same. */
switch (u8_uctomb_aux (c, uc, 6))
{
case 2:
- if (*s == 0 || s[1] == 0)
- break;
+ if (*s == 0)
+ goto notfound;
{
uint8_t c0 = c[0];
uint8_t c1 = c[1];
- /* Search for { c0, c1 }. */
- uint8_t s1 = s[1];
- for (;;)
+ for (;; s++)
{
- /* Here s[0] != 0, s[1] != 0.
- Test whether s[0..1] == { c0, c1 }. */
- if (s1 == c1)
- {
- if (*s == c0)
- return (uint8_t *) s;
- else
- /* Skip the search at s + 1, because s[1] = c1 < c0. */
- goto case2_skip2;
- }
- else
- {
- if (s1 == c0)
- goto case2_skip1;
- else
- /* Skip the search at s + 1, because s[1] != c0. */
- goto case2_skip2;
- }
- case2_skip2:
- s++;
- s1 = s[1];
- if (s[1] == 0)
- break;
- case2_skip1:
- s++;
- s1 = s[1];
if (s[1] == 0)
+ goto notfound;
+ if (*s == c0 && s[1] == c1)
break;
}
+ return (uint8_t *) s;
}
- break;
case 3:
- if (*s == 0 || s[1] == 0 || s[2] == 0)
- break;
+ if (*s == 0 || s[1] == 0)
+ goto notfound;
{
uint8_t c0 = c[0];
uint8_t c1 = c[1];
uint8_t c2 = c[2];
- /* Search for { c0, c1, c2 }. */
- uint8_t s2 = s[2];
- for (;;)
+ for (;; s++)
{
- /* Here s[0] != 0, s[1] != 0, s[2] != 0.
- Test whether s[0..2] == { c0, c1, c2 }. */
- if (s2 == c2)
- {
- if (s[1] == c1 && *s == c0)
- return (uint8_t *) s;
- else
- /* If c2 != c1:
- Skip the search at s + 1, because s[2] == c2 != c1.
- Skip the search at s + 2, because s[2] == c2 < c0. */
- if (c2 == c1)
- goto case3_skip1;
- else
- goto case3_skip3;
- }
- else
- {
- if (s2 == c1)
- goto case3_skip1;
- else if (s2 == c0)
- /* Skip the search at s + 1, because s[2] != c1. */
- goto case3_skip2;
- else
- /* Skip the search at s + 1, because s[2] != c1.
- Skip the search at s + 2, because s[2] != c0. */
- goto case3_skip3;
- }
- case3_skip3:
- s++;
- s2 = s[2];
- if (s[2] == 0)
- break;
- case3_skip2:
- s++;
- s2 = s[2];
- if (s[2] == 0)
- break;
- case3_skip1:
- s++;
- s2 = s[2];
if (s[2] == 0)
+ goto notfound;
+ if (*s == c0 && s[1] == c1 && s[2] == c2)
break;
}
+ return (uint8_t *) s;
}
- break;
case 4:
- if (*s == 0 || s[1] == 0 || s[2] == 0 || s[3] == 0)
- break;
+ if (*s == 0 || s[1] == 0 || s[2] == 0)
+ goto notfound;
{
uint8_t c0 = c[0];
uint8_t c1 = c[1];
uint8_t c2 = c[2];
uint8_t c3 = c[3];
- /* Search for { c0, c1, c2, c3 }. */
- uint8_t s3 = s[3];
- for (;;)
+ for (;; s++)
{
- /* Here s[0] != 0, s[1] != 0, s[2] != 0, s[3] != 0.
- Test whether s[0..3] == { c0, c1, c2, c3 }. */
- if (s3 == c3)
- {
- if (s[2] == c2 && s[1] == c1 && *s == c0)
- return (uint8_t *) s;
- else
- /* If c3 != c2:
- Skip the search at s + 1, because s[3] == c3 != c2.
- If c3 != c1:
- Skip the search at s + 2, because s[3] == c3 != c1.
- Skip the search at s + 3, because s[3] == c3 < c0. */
- if (c3 == c2)
- goto case4_skip1;
- else if (c3 == c1)
- goto case4_skip2;
- else
- goto case4_skip4;
- }
- else
- {
- if (s3 == c2)
- goto case4_skip1;
- else if (s3 == c1)
- /* Skip the search at s + 1, because s[3] != c2. */
- goto case4_skip2;
- else if (s3 == c0)
- /* Skip the search at s + 1, because s[3] != c2.
- Skip the search at s + 2, because s[3] != c1. */
- goto case4_skip3;
- else
- /* Skip the search at s + 1, because s[3] != c2.
- Skip the search at s + 2, because s[3] != c1.
- Skip the search at s + 3, because s[3] != c0. */
- goto case4_skip4;
- }
- case4_skip4:
- s++;
- s3 = s[3];
- if (s[3] == 0)
- break;
- case4_skip3:
- s++;
- s3 = s[3];
- if (s[3] == 0)
- break;
- case4_skip2:
- s++;
- s3 = s[3];
- if (s[3] == 0)
- break;
- case4_skip1:
- s++;
- s3 = s[3];
if (s[3] == 0)
+ goto notfound;
+ if (*s == c0 && s[1] == c1 && s[2] == c2 && s[3] == c3)
break;
}
+ return (uint8_t *) s;
}
- break;
}
-
+notfound:
return NULL;
}