From e8bd88d1fcded01ccd066572eeaae1b507989cb3 Mon Sep 17 00:00:00 2001
From: RincewindsHat <12514511+RincewindsHat@users.noreply.github.com>
Date: Tue, 31 Jan 2023 14:46:01 +0100
Subject: Sync with the latest Gnulib code 668c0b8ffa
---
gl/intprops.h | 250 +++++++++++++++++++++++++++++++---------------------------
1 file changed, 133 insertions(+), 117 deletions(-)
(limited to 'gl/intprops.h')
diff --git a/gl/intprops.h b/gl/intprops.h
index f57f9b4d..44b5e60f 100644
--- a/gl/intprops.h
+++ b/gl/intprops.h
@@ -1,34 +1,24 @@
/* intprops.h -- properties of integer types
- Copyright (C) 2001-2005, 2009-2013 Free Software Foundation, Inc.
+ Copyright (C) 2001-2023 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 Lesser General Public License as published
+ by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
+ GNU Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see . */
-
-/* Written by Paul Eggert. */
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see . */
#ifndef _GL_INTPROPS_H
#define _GL_INTPROPS_H
-#include
-
-/* Return an integer value, converted to the same type as the integer
- expression E after integer type promotion. V is the unconverted value. */
-#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
- . */
-#define _GL_INT_NEGATE_CONVERT(e, v) (0 * (e) - (v))
+#include "intprops-internal.h"
/* The extra casts in the following macros work around compiler bugs,
e.g., in Cray C 5.0.3.0. */
@@ -37,72 +27,27 @@
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 real type T is signed. */
+#define TYPE_SIGNED(t) _GL_TYPE_SIGNED (t)
-/* True if the signed integer expression E uses two's complement. */
-#define _GL_INT_TWOS_COMPLEMENT(e) (~ _GL_INT_CONVERT (e, 0) == -1)
+/* Return 1 if the real expression E, after promotion, has a
+ signed or floating type. Do not evaluate E. */
+#define EXPR_SIGNED(e) _GL_EXPR_SIGNED (e)
-/* True if the arithmetic 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)
+/* Minimum and maximum values for integer types and expressions. */
-
-/* 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. */
+/* The width in bits of the integer type or expression T.
+ Do not evaluate T. T must not be a bit-field expression.
+ Padding bits are not supported; this is checked at compile-time below. */
+#define TYPE_WIDTH(t) _GL_TYPE_WIDTH (t)
/* 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)))
-
-/* 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) \
- : _GL_INT_CONVERT (e, 0))
-#define _GL_INT_MAXIMUM(e) \
- (_GL_INT_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)
-
-
-/* Return 1 if the __typeof__ keyword works. This could be done by
- 'configure', but for now it's easier to do it by hand. */
-#if 2 <= __GNUC__ || defined __IBM__TYPEOF__ || 0x5110 <= __SUNPRO_C
-# define _GL_HAVE___TYPEOF__ 1
-#else
-# define _GL_HAVE___TYPEOF__ 0
-#endif
-
-/* Return 1 if the integer type or expression T might be signed. Return 0
- if it is definitely unsigned. This macro does not evaluate its argument,
- and expands to an integer constant expression. */
-#if _GL_HAVE___TYPEOF__
-# define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t))
-#else
-# define _GL_SIGNED_TYPE_OR_EXPR(t) 1
-#endif
+ : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1)))
/* Bound on length of the string representing an unsigned integer
value representable in B bits. log10 (2.0) < 146/485. The
@@ -110,30 +55,31 @@
#define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485)
/* Bound on length of the string representing an integer type or expression T.
+ T must not be a bit-field expression.
+
Subtract 1 for the sign bit if T is signed, and then add 1 more for
a minus sign if needed.
- Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 0 when its argument is
- signed, this macro may overestimate the true bound by one byte when
+ Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 1 when its argument is
+ unsigned, 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,
- including the terminating null. */
+ including the terminating null. T must not be a bit-field expression. */
#define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
/* Range overflow checks.
The INT__RANGE_OVERFLOW macros return 1 if the corresponding C
- operators might not yield numerically correct answers due to
- arithmetic overflow. They do not rely on undefined or
- implementation-defined behavior. Their implementations are simple
- and straightforward, but they are a bit harder to use than the
- INT__OVERFLOW macros described below.
+ operators overflow arithmetically when given the same arguments.
+ These macros do not rely on undefined or implementation-defined behavior.
+ Although their implementations are simple and straightforward,
+ they are harder to use and may be less efficient than the
+ INT__WRAPV, INT__OK, and INT__OVERFLOW macros described below.
Example usage:
@@ -157,6 +103,9 @@
must have minimum value MIN and maximum MAX. Unsigned types should
use a zero MIN of the proper type.
+ Because all arguments are subject to integer promotions, these
+ macros typically do not work on types narrower than 'int'.
+
These macros are tuned for constant MIN and MAX. For commutative
operations such as A + B, they are also tuned for constant B. */
@@ -177,14 +126,12 @@
/* Return 1 if - A would overflow in [MIN,MAX] arithmetic.
See above for restrictions. */
#define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \
- ((min) < 0 \
- ? (a) < - (max) \
- : 0 < (a))
+ _GL_INT_NEGATE_RANGE_OVERFLOW (a, min, max)
/* Return 1 if A * B would overflow in [MIN,MAX] arithmetic.
See above for restrictions. Avoid && and || as they tickle
bugs in Sun C 5.11 2010/08/13 and other compilers; see
- . */
+ . */
#define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max) \
((b) < 0 \
? ((a) < 0 \
@@ -223,24 +170,32 @@
? (a) < (min) >> (b) \
: (max) >> (b) < (a))
-
/* 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 \
@@ -262,22 +217,31 @@
: (a) % - (b)) \
== 0)
-
-/* Integer overflow checks.
+/* Check for integer overflow, and report low order bits of answer.
The INT__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__WRAPV macros compute the low-order bits of the sum,
+ difference, and product of two C integers, and return 1 if these
+ low-order bits are not numerically correct.
+ 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
@@ -286,7 +250,23 @@
These macros may evaluate their arguments zero or multiple times, so the
arguments should not have side effects.
- These macros are tuned for their last argument being a constant.
+ The WRAPV macros are not constant expressions. They support only
+ +, binary -, and *.
+
+ Because the WRAPV macros convert the result, they report overflow
+ in different circumstances than the OVERFLOW macros do. For
+ example, in the typical case with 16-bit 'short' and 32-bit 'int',
+ if A, B and *R are all of type 'short' then INT_ADD_OVERFLOW (A, B)
+ returns false because the addition cannot overflow after A and B
+ are converted to 'int', whereas INT_ADD_WRAPV (A, B, R) returns
+ true or false depending on whether the sum fits into 'short'.
+
+ These macros are tuned for their last input argument being a constant.
+
+ A, B, and *R should be integers; they need not be the same type,
+ and they need not be all signed or all unsigned.
+ However, none of the integer types should be bit-precise,
+ and *R's type should not be char, bool, or an enumeration type.
Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B,
A % B, and A << B would overflow, respectively. */
@@ -295,8 +275,7 @@
_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))
+#define INT_NEGATE_OVERFLOW(a) _GL_INT_NEGATE_OVERFLOW (a)
#define INT_MULTIPLY_OVERFLOW(a, b) \
_GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW)
#define INT_DIVIDE_OVERFLOW(a, b) \
@@ -313,7 +292,44 @@
Arguments should be free of side effects. */
#define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \
op_result_overflow (a, b, \
- _GL_INT_MINIMUM (0 * (b) + (a)), \
- _GL_INT_MAXIMUM (0 * (b) + (a)))
+ _GL_INT_MINIMUM (_GL_INT_CONVERT (a, b)), \
+ _GL_INT_MAXIMUM (_GL_INT_CONVERT (a, b)))
+
+/* 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_ADD_WRAPV (a, b, r)
+#define INT_SUBTRACT_WRAPV(a, b, r) _GL_INT_SUBTRACT_WRAPV (a, b, r)
+#define INT_MULTIPLY_WRAPV(a, b, r) _GL_INT_MULTIPLY_WRAPV (a, b, r)
+
+/* The following macros compute A + B, A - B, and A * B, respectively.
+ If no overflow occurs, they set *R to the result and return 1;
+ otherwise, they return 0 and may modify *R.
+
+ Example usage:
+
+ long int result;
+ if (INT_ADD_OK (a, b, &result))
+ printf ("result is %ld\n", result);
+ else
+ printf ("overflow\n");
+
+ A, B, and *R should be integers; they need not be the same type,
+ and they need not be all signed or all unsigned.
+ However, none of the integer types should be bit-precise,
+ and *R's type should not be char, bool, or an enumeration type.
+
+ These macros work correctly on all known practical hosts, and do not rely
+ on undefined behavior due to signed arithmetic overflow.
+
+ These macros are not constant expressions.
+
+ These macros may evaluate their arguments zero or multiple times, so the
+ arguments should not have side effects.
+
+ These macros are tuned for B being a constant. */
+
+#define INT_ADD_OK(a, b, r) (! INT_ADD_WRAPV (a, b, r))
+#define INT_SUBTRACT_OK(a, b, r) (! INT_SUBTRACT_WRAPV (a, b, r))
+#define INT_MULTIPLY_OK(a, b, r) (! INT_MULTIPLY_WRAPV (a, b, r))
#endif /* _GL_INTPROPS_H */
--
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