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-rw-r--r--tests/intprops.h272
1 files changed, 208 insertions, 64 deletions
diff --git a/tests/intprops.h b/tests/intprops.h
index f85ccade..8add5def 100644
--- a/tests/intprops.h
+++ b/tests/intprops.h
@@ -1,10 +1,10 @@
/* intprops.h -- properties of integer types
- Copyright (C) 2001-2005, 2009-2015 Free Software Foundation, Inc.
+ Copyright (C) 2001-2016 Free Software Foundation, Inc.
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
@@ -21,9 +21,13 @@
#define _GL_INTPROPS_H
#include <limits.h>
+#include <verify.h>
-/* Return an integer value, converted to the same type as the integer
- expression E after integer type promotion. V is the unconverted value. */
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
+/* Return a value with the common real type of E and V and the value of V. */
#define _GL_INT_CONVERT(e, v) (0 * (e) + (v))
/* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see
@@ -37,59 +41,72 @@
an integer. */
#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
-/* True if negative values of the signed integer type T use two's
- complement, ones' complement, or signed magnitude representation,
- respectively. Much GNU code assumes two's complement, but some
- people like to be portable to all possible C hosts. */
-#define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
-#define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
-#define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
-
-/* True if the signed integer expression E uses two's complement. */
-#define _GL_INT_TWOS_COMPLEMENT(e) (~ _GL_INT_CONVERT (e, 0) == -1)
-
-/* True if the arithmetic type T is signed. */
+/* True if the real type T is signed. */
#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
-/* Return 1 if the integer expression E, after integer promotion, has
- a signed type. */
-#define _GL_INT_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0)
+/* Return 1 if the real expression E, after promotion, has a
+ signed or floating type. */
+#define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0)
-/* Minimum and maximum values for integer types and expressions. These
- macros have undefined behavior if T is signed and has padding bits.
- If this is a problem for you, please let us know how to fix it for
- your host. */
+/* Minimum and maximum values for integer types and expressions. */
+
+/* The width in bits of the integer type or expression T.
+ Padding bits are not supported; this is checked at compile-time below. */
+#define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT)
/* The maximum and minimum values for the integer type T. */
-#define TYPE_MINIMUM(t) \
- ((t) (! TYPE_SIGNED (t) \
- ? (t) 0 \
- : TYPE_SIGNED_MAGNITUDE (t) \
- ? ~ (t) 0 \
- : ~ TYPE_MAXIMUM (t)))
+#define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t))
#define TYPE_MAXIMUM(t) \
((t) (! TYPE_SIGNED (t) \
? (t) -1 \
- : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
+ : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1)))
/* The maximum and minimum values for the type of the expression E,
after integer promotion. E should not have side effects. */
#define _GL_INT_MINIMUM(e) \
- (_GL_INT_SIGNED (e) \
- ? - _GL_INT_TWOS_COMPLEMENT (e) - _GL_SIGNED_INT_MAXIMUM (e) \
+ (EXPR_SIGNED (e) \
+ ? ~ _GL_SIGNED_INT_MAXIMUM (e) \
: _GL_INT_CONVERT (e, 0))
#define _GL_INT_MAXIMUM(e) \
- (_GL_INT_SIGNED (e) \
+ (EXPR_SIGNED (e) \
? _GL_SIGNED_INT_MAXIMUM (e) \
: _GL_INT_NEGATE_CONVERT (e, 1))
#define _GL_SIGNED_INT_MAXIMUM(e) \
- (((_GL_INT_CONVERT (e, 1) << (sizeof ((e) + 0) * CHAR_BIT - 2)) - 1) * 2 + 1)
+ (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH ((e) + 0) - 2)) - 1) * 2 + 1)
+
+/* Work around OpenVMS incompatibility with C99. */
+#if !defined LLONG_MAX && defined __INT64_MAX
+# define LLONG_MAX __INT64_MAX
+# define LLONG_MIN __INT64_MIN
+#endif
+/* This include file assumes that signed types are two's complement without
+ padding bits; the above macros have undefined behavior otherwise.
+ If this is a problem for you, please let us know how to fix it for your host.
+ As a sanity check, test the assumption for some signed types that
+ <limits.h> bounds. */
+verify (TYPE_MINIMUM (signed char) == SCHAR_MIN);
+verify (TYPE_MAXIMUM (signed char) == SCHAR_MAX);
+verify (TYPE_MINIMUM (short int) == SHRT_MIN);
+verify (TYPE_MAXIMUM (short int) == SHRT_MAX);
+verify (TYPE_MINIMUM (int) == INT_MIN);
+verify (TYPE_MAXIMUM (int) == INT_MAX);
+verify (TYPE_MINIMUM (long int) == LONG_MIN);
+verify (TYPE_MAXIMUM (long int) == LONG_MAX);
+#ifdef LLONG_MAX
+verify (TYPE_MINIMUM (long long int) == LLONG_MIN);
+verify (TYPE_MAXIMUM (long long int) == LLONG_MAX);
+#endif
+/* Similarly, sanity-check one ISO/IEC TS 18661-1:2014 macro if defined. */
+#ifdef UINT_WIDTH
+verify (TYPE_WIDTH (unsigned int) == UINT_WIDTH);
+#endif
-/* Return 1 if the __typeof__ keyword works. This could be done by
+/* Does the __typeof__ keyword work? This could be done by
'configure', but for now it's easier to do it by hand. */
-#if (2 <= __GNUC__ || defined __IBM__TYPEOF__ \
+#if (2 <= __GNUC__ \
+ || (1210 <= __IBMC__ && defined __IBM__TYPEOF__) \
|| (0x5110 <= __SUNPRO_C && !__STDC__))
# define _GL_HAVE___TYPEOF__ 1
#else
@@ -118,8 +135,7 @@
signed, this macro may overestimate the true bound by one byte when
applied to unsigned types of size 2, 4, 16, ... bytes. */
#define INT_STRLEN_BOUND(t) \
- (INT_BITS_STRLEN_BOUND (sizeof (t) * CHAR_BIT \
- - _GL_SIGNED_TYPE_OR_EXPR (t)) \
+ (INT_BITS_STRLEN_BOUND (TYPE_WIDTH (t) - _GL_SIGNED_TYPE_OR_EXPR (t)) \
+ _GL_SIGNED_TYPE_OR_EXPR (t))
/* Bound on buffer size needed to represent an integer type or expression T,
@@ -224,24 +240,40 @@
? (a) < (min) >> (b) \
: (max) >> (b) < (a))
+/* True if __builtin_add_overflow (A, B, P) works when P is non-null. */
+#define _GL_HAS_BUILTIN_OVERFLOW \
+ (5 <= __GNUC__ || __has_builtin (__builtin_add_overflow))
+
+/* True if __builtin_add_overflow_p (A, B, C) works. */
+#define _GL_HAS_BUILTIN_OVERFLOW_P \
+ (7 <= __GNUC__ || __has_builtin (__builtin_add_overflow_p))
/* The _GL*_OVERFLOW macros have the same restrictions as the
*_RANGE_OVERFLOW macros, except that they do not assume that operands
(e.g., A and B) have the same type as MIN and MAX. Instead, they assume
that the result (e.g., A + B) has that type. */
-#define _GL_ADD_OVERFLOW(a, b, min, max) \
- ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \
- : (a) < 0 ? (b) <= (a) + (b) \
- : (b) < 0 ? (a) <= (a) + (b) \
- : (a) + (b) < (b))
-#define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \
- ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max) \
- : (a) < 0 ? 1 \
- : (b) < 0 ? (a) - (b) <= (a) \
- : (a) < (b))
-#define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \
- (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \
- || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max))
+#if _GL_HAS_BUILTIN_OVERFLOW_P
+# define _GL_ADD_OVERFLOW(a, b, min, max) \
+ __builtin_add_overflow_p (a, b, (__typeof__ ((a) + (b))) 0)
+# define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \
+ __builtin_sub_overflow_p (a, b, (__typeof__ ((a) - (b))) 0)
+# define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \
+ __builtin_mul_overflow_p (a, b, (__typeof__ ((a) * (b))) 0)
+#else
+# define _GL_ADD_OVERFLOW(a, b, min, max) \
+ ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \
+ : (a) < 0 ? (b) <= (a) + (b) \
+ : (b) < 0 ? (a) <= (a) + (b) \
+ : (a) + (b) < (b))
+# define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \
+ ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max) \
+ : (a) < 0 ? 1 \
+ : (b) < 0 ? (a) - (b) <= (a) \
+ : (a) < (b))
+# define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \
+ (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \
+ || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max))
+#endif
#define _GL_DIVIDE_OVERFLOW(a, b, min, max) \
((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \
: (a) < 0 ? (b) <= (a) + (b) - 1 \
@@ -263,22 +295,29 @@
: (a) % - (b)) \
== 0)
-
-/* Integer overflow checks.
+/* Check for integer overflow, and report low order bits of answer.
The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators
might not yield numerically correct answers due to arithmetic overflow.
- They work correctly on all known practical hosts, and do not rely
+ The INT_<op>_WRAPV macros also store the low-order bits of the answer.
+ These macros work correctly on all known practical hosts, and do not rely
on undefined behavior due to signed arithmetic overflow.
- Example usage:
+ Example usage, assuming A and B are long int:
- long int i = ...;
- long int j = ...;
- if (INT_MULTIPLY_OVERFLOW (i, j))
- printf ("multiply would overflow");
+ if (INT_MULTIPLY_OVERFLOW (a, b))
+ printf ("result would overflow\n");
else
- printf ("product is %ld", i * j);
+ printf ("result is %ld (no overflow)\n", a * b);
+
+ Example usage with WRAPV flavor:
+
+ long int result;
+ bool overflow = INT_MULTIPLY_WRAPV (a, b, &result);
+ printf ("result is %ld (%s)\n", result,
+ overflow ? "after overflow" : "no overflow");
+
+ Restrictions on these macros:
These macros do not check for all possible numerical problems or
undefined or unspecified behavior: they do not check for division
@@ -287,6 +326,9 @@
These macros may evaluate their arguments zero or multiple times, so the
arguments should not have side effects.
+ The WRAPV macros are not constant expressions. They support only
+ +, binary -, and *. The result type must be signed.
+
These macros are tuned for their last argument being a constant.
Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B,
@@ -296,8 +338,12 @@
_GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW)
#define INT_SUBTRACT_OVERFLOW(a, b) \
_GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW)
-#define INT_NEGATE_OVERFLOW(a) \
- INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
+#if _GL_HAS_BUILTIN_OVERFLOW_P
+# define INT_NEGATE_OVERFLOW(a) INT_SUBTRACT_OVERFLOW (0, a)
+#else
+# define INT_NEGATE_OVERFLOW(a) \
+ INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
+#endif
#define INT_MULTIPLY_OVERFLOW(a, b) \
_GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW)
#define INT_DIVIDE_OVERFLOW(a, b) \
@@ -317,4 +363,102 @@
_GL_INT_MINIMUM (0 * (b) + (a)), \
_GL_INT_MAXIMUM (0 * (b) + (a)))
+/* Store the low-order bits of A + B, A - B, A * B, respectively, into *R.
+ Return 1 if the result overflows. See above for restrictions. */
+#define INT_ADD_WRAPV(a, b, r) \
+ _GL_INT_OP_WRAPV (a, b, r, +, __builtin_add_overflow, INT_ADD_OVERFLOW)
+#define INT_SUBTRACT_WRAPV(a, b, r) \
+ _GL_INT_OP_WRAPV (a, b, r, -, __builtin_sub_overflow, INT_SUBTRACT_OVERFLOW)
+#define INT_MULTIPLY_WRAPV(a, b, r) \
+ _GL_INT_OP_WRAPV (a, b, r, *, __builtin_mul_overflow, INT_MULTIPLY_OVERFLOW)
+
+/* Nonzero if this compiler has GCC bug 68193 or Clang bug 25390. See:
+ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193
+ https://llvm.org/bugs/show_bug.cgi?id=25390
+ For now, assume all versions of GCC-like compilers generate bogus
+ warnings for _Generic. This matters only for older compilers that
+ lack __builtin_add_overflow. */
+#if __GNUC__
+# define _GL__GENERIC_BOGUS 1
+#else
+# define _GL__GENERIC_BOGUS 0
+#endif
+
+/* Store the low-order bits of A <op> B into *R, where OP specifies
+ the operation. BUILTIN is the builtin operation, and OVERFLOW the
+ overflow predicate. Return 1 if the result overflows. See above
+ for restrictions. */
+#if _GL_HAS_BUILTIN_OVERFLOW
+# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) builtin (a, b, r)
+#elif 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS
+# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
+ (_Generic \
+ (*(r), \
+ signed char: \
+ _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \
+ signed char, SCHAR_MIN, SCHAR_MAX), \
+ short int: \
+ _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \
+ short int, SHRT_MIN, SHRT_MAX), \
+ int: \
+ _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+ int, INT_MIN, INT_MAX), \
+ long int: \
+ _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+ long int, LONG_MIN, LONG_MAX), \
+ long long int: \
+ _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+ long long int, LLONG_MIN, LLONG_MAX)))
+#else
+# define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \
+ (sizeof *(r) == sizeof (signed char) \
+ ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \
+ signed char, SCHAR_MIN, SCHAR_MAX) \
+ : sizeof *(r) == sizeof (short int) \
+ ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \
+ short int, SHRT_MIN, SHRT_MAX) \
+ : sizeof *(r) == sizeof (int) \
+ ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
+ int, INT_MIN, INT_MAX) \
+ : _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow))
+# ifdef LLONG_MAX
+# define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
+ (sizeof *(r) == sizeof (long int) \
+ ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+ long int, LONG_MIN, LONG_MAX) \
+ : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
+ long long int, LLONG_MIN, LLONG_MAX))
+# else
+# define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
+ _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
+ long int, LONG_MIN, LONG_MAX)
+# endif
+#endif
+
+/* Store the low-order bits of A <op> B into *R, where the operation
+ is given by OP. Use the unsigned type UT for calculation to avoid
+ overflow problems. *R's type is T, with extremal values TMIN and
+ TMAX. T must be a signed integer type. Return 1 if the result
+ overflows. */
+#define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \
+ (sizeof ((a) op (b)) < sizeof (t) \
+ ? _GL_INT_OP_CALC1 ((t) (a), (t) (b), r, op, overflow, ut, t, tmin, tmax) \
+ : _GL_INT_OP_CALC1 (a, b, r, op, overflow, ut, t, tmin, tmax))
+#define _GL_INT_OP_CALC1(a, b, r, op, overflow, ut, t, tmin, tmax) \
+ ((overflow (a, b) \
+ || (EXPR_SIGNED ((a) op (b)) && ((a) op (b)) < (tmin)) \
+ || (tmax) < ((a) op (b))) \
+ ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 1) \
+ : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 0))
+
+/* Return A <op> B, where the operation is given by OP. Use the
+ unsigned type UT for calculation to avoid overflow problems.
+ Convert the result to type T without overflow by subtracting TMIN
+ from large values before converting, and adding it afterwards.
+ Compilers can optimize all the operations except OP. */
+#define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t, tmin, tmax) \
+ (((ut) (a) op (ut) (b)) <= (tmax) \
+ ? (t) ((ut) (a) op (ut) (b)) \
+ : ((t) (((ut) (a) op (ut) (b)) - (tmin)) + (tmin)))
+
#endif /* _GL_INTPROPS_H */