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-rw-r--r--gl/intprops.h358
1 files changed, 27 insertions, 331 deletions
diff --git a/gl/intprops.h b/gl/intprops.h
index 3fe64e8..f182ddc 100644
--- a/gl/intprops.h
+++ b/gl/intprops.h
@@ -1,6 +1,6 @@
1/* intprops.h -- properties of integer types 1/* intprops.h -- properties of integer types
2 2
3 Copyright (C) 2001-2021 Free Software Foundation, Inc. 3 Copyright (C) 2001-2022 Free Software Foundation, Inc.
4 4
5 This program is free software: you can redistribute it and/or modify it 5 This program is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Lesser General Public License as published 6 under the terms of the GNU Lesser General Public License as published
@@ -15,19 +15,10 @@
15 You should have received a copy of the GNU Lesser General Public License 15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17 17
18
19#ifndef _GL_INTPROPS_H 18#ifndef _GL_INTPROPS_H
20#define _GL_INTPROPS_H 19#define _GL_INTPROPS_H
21 20
22#include <limits.h> 21#include "intprops-internal.h"
23
24/* Return a value with the common real type of E and V and the value of V.
25 Do not evaluate E. */
26#define _GL_INT_CONVERT(e, v) ((1 ? 0 : (e)) + (v))
27
28/* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see
29 <https://lists.gnu.org/r/bug-gnulib/2011-05/msg00406.html>. */
30#define _GL_INT_NEGATE_CONVERT(e, v) ((1 ? 0 : (e)) - (v))
31 22
32/* The extra casts in the following macros work around compiler bugs, 23/* The extra casts in the following macros work around compiler bugs,
33 e.g., in Cray C 5.0.3.0. */ 24 e.g., in Cray C 5.0.3.0. */
@@ -37,11 +28,11 @@
37#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) 28#define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
38 29
39/* True if the real type T is signed. */ 30/* True if the real type T is signed. */
40#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) 31#define TYPE_SIGNED(t) _GL_TYPE_SIGNED (t)
41 32
42/* Return 1 if the real expression E, after promotion, has a 33/* Return 1 if the real expression E, after promotion, has a
43 signed or floating type. Do not evaluate E. */ 34 signed or floating type. Do not evaluate E. */
44#define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0) 35#define EXPR_SIGNED(e) _GL_EXPR_SIGNED (e)
45 36
46 37
47/* Minimum and maximum values for integer types and expressions. */ 38/* Minimum and maximum values for integer types and expressions. */
@@ -49,7 +40,7 @@
49/* The width in bits of the integer type or expression T. 40/* The width in bits of the integer type or expression T.
50 Do not evaluate T. T must not be a bit-field expression. 41 Do not evaluate T. T must not be a bit-field expression.
51 Padding bits are not supported; this is checked at compile-time below. */ 42 Padding bits are not supported; this is checked at compile-time below. */
52#define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT) 43#define TYPE_WIDTH(t) _GL_TYPE_WIDTH (t)
53 44
54/* The maximum and minimum values for the integer type T. */ 45/* The maximum and minimum values for the integer type T. */
55#define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t)) 46#define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t))
@@ -58,51 +49,6 @@
58 ? (t) -1 \ 49 ? (t) -1 \
59 : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1))) 50 : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1)))
60 51
61/* The maximum and minimum values for the type of the expression E,
62 after integer promotion. E is not evaluated. */
63#define _GL_INT_MINIMUM(e) \
64 (EXPR_SIGNED (e) \
65 ? ~ _GL_SIGNED_INT_MAXIMUM (e) \
66 : _GL_INT_CONVERT (e, 0))
67#define _GL_INT_MAXIMUM(e) \
68 (EXPR_SIGNED (e) \
69 ? _GL_SIGNED_INT_MAXIMUM (e) \
70 : _GL_INT_NEGATE_CONVERT (e, 1))
71#define _GL_SIGNED_INT_MAXIMUM(e) \
72 (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH (+ (e)) - 2)) - 1) * 2 + 1)
73
74/* Work around OpenVMS incompatibility with C99. */
75#if !defined LLONG_MAX && defined __INT64_MAX
76# define LLONG_MAX __INT64_MAX
77# define LLONG_MIN __INT64_MIN
78#endif
79
80/* This include file assumes that signed types are two's complement without
81 padding bits; the above macros have undefined behavior otherwise.
82 If this is a problem for you, please let us know how to fix it for your host.
83 This assumption is tested by the intprops-tests module. */
84
85/* Does the __typeof__ keyword work? This could be done by
86 'configure', but for now it's easier to do it by hand. */
87#if (2 <= __GNUC__ \
88 || (4 <= __clang_major__) \
89 || (1210 <= __IBMC__ && defined __IBM__TYPEOF__) \
90 || (0x5110 <= __SUNPRO_C && !__STDC__))
91# define _GL_HAVE___TYPEOF__ 1
92#else
93# define _GL_HAVE___TYPEOF__ 0
94#endif
95
96/* Return 1 if the integer type or expression T might be signed. Return 0
97 if it is definitely unsigned. T must not be a bit-field expression.
98 This macro does not evaluate its argument, and expands to an
99 integer constant expression. */
100#if _GL_HAVE___TYPEOF__
101# define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t))
102#else
103# define _GL_SIGNED_TYPE_OR_EXPR(t) 1
104#endif
105
106/* Bound on length of the string representing an unsigned integer 52/* Bound on length of the string representing an unsigned integer
107 value representable in B bits. log10 (2.0) < 146/485. The 53 value representable in B bits. log10 (2.0) < 146/485. The
108 smallest value of B where this bound is not tight is 2621. */ 54 smallest value of B where this bound is not tight is 2621. */
@@ -129,12 +75,11 @@
129/* Range overflow checks. 75/* Range overflow checks.
130 76
131 The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C 77 The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C
132 operators might not yield numerically correct answers due to 78 operators overflow arithmetically when given the same arguments.
133 arithmetic overflow. They do not rely on undefined or 79 These macros do not rely on undefined or implementation-defined behavior.
134 implementation-defined behavior. Their implementations are simple 80 Although their implementations are simple and straightforward,
135 and straightforward, but they are harder to use and may be less 81 they are harder to use and may be less efficient than the
136 efficient than the INT_<op>_WRAPV, INT_<op>_OK, and 82 INT_<op>_WRAPV, INT_<op>_OK, and INT_<op>_OVERFLOW macros described below.
137 INT_<op>_OVERFLOW macros described below.
138 83
139 Example usage: 84 Example usage:
140 85
@@ -181,9 +126,7 @@
181/* Return 1 if - A would overflow in [MIN,MAX] arithmetic. 126/* Return 1 if - A would overflow in [MIN,MAX] arithmetic.
182 See above for restrictions. */ 127 See above for restrictions. */
183#define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \ 128#define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \
184 ((min) < 0 \ 129 _GL_INT_NEGATE_RANGE_OVERFLOW (a, min, max)
185 ? (a) < - (max) \
186 : 0 < (a))
187 130
188/* Return 1 if A * B would overflow in [MIN,MAX] arithmetic. 131/* Return 1 if A * B would overflow in [MIN,MAX] arithmetic.
189 See above for restrictions. Avoid && and || as they tickle 132 See above for restrictions. Avoid && and || as they tickle
@@ -227,40 +170,6 @@
227 ? (a) < (min) >> (b) \ 170 ? (a) < (min) >> (b) \
228 : (max) >> (b) < (a)) 171 : (max) >> (b) < (a))
229 172
230/* True if __builtin_add_overflow (A, B, P) and __builtin_sub_overflow
231 (A, B, P) work when P is non-null. */
232/* __builtin_{add,sub}_overflow exists but is not reliable in GCC 5.x and 6.x,
233 see <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98269>. */
234#if 7 <= __GNUC__ && !defined __ICC
235# define _GL_HAS_BUILTIN_ADD_OVERFLOW 1
236#elif defined __has_builtin
237# define _GL_HAS_BUILTIN_ADD_OVERFLOW __has_builtin (__builtin_add_overflow)
238#else
239# define _GL_HAS_BUILTIN_ADD_OVERFLOW 0
240#endif
241
242/* True if __builtin_mul_overflow (A, B, P) works when P is non-null. */
243#ifdef __clang__
244/* Work around Clang bug <https://bugs.llvm.org/show_bug.cgi?id=16404>. */
245# define _GL_HAS_BUILTIN_MUL_OVERFLOW 0
246#else
247# define _GL_HAS_BUILTIN_MUL_OVERFLOW _GL_HAS_BUILTIN_ADD_OVERFLOW
248#endif
249
250/* True if __builtin_add_overflow_p (A, B, C) works, and similarly for
251 __builtin_sub_overflow_p and __builtin_mul_overflow_p. */
252#if defined __clang__ || defined __ICC
253/* Clang 11 lacks __builtin_mul_overflow_p, and even if it did it
254 would presumably run afoul of Clang bug 16404. ICC 2021.1's
255 __builtin_add_overflow_p etc. are not treated as integral constant
256 expressions even when all arguments are. */
257# define _GL_HAS_BUILTIN_OVERFLOW_P 0
258#elif defined __has_builtin
259# define _GL_HAS_BUILTIN_OVERFLOW_P __has_builtin (__builtin_mul_overflow_p)
260#else
261# define _GL_HAS_BUILTIN_OVERFLOW_P (7 <= __GNUC__)
262#endif
263
264/* The _GL*_OVERFLOW macros have the same restrictions as the 173/* The _GL*_OVERFLOW macros have the same restrictions as the
265 *_RANGE_OVERFLOW macros, except that they do not assume that operands 174 *_RANGE_OVERFLOW macros, except that they do not assume that operands
266 (e.g., A and B) have the same type as MIN and MAX. Instead, they assume 175 (e.g., A and B) have the same type as MIN and MAX. Instead, they assume
@@ -347,13 +256,18 @@
347 Because the WRAPV macros convert the result, they report overflow 256 Because the WRAPV macros convert the result, they report overflow
348 in different circumstances than the OVERFLOW macros do. For 257 in different circumstances than the OVERFLOW macros do. For
349 example, in the typical case with 16-bit 'short' and 32-bit 'int', 258 example, in the typical case with 16-bit 'short' and 32-bit 'int',
350 if A, B and R are all of type 'short' then INT_ADD_OVERFLOW (A, B) 259 if A, B and *R are all of type 'short' then INT_ADD_OVERFLOW (A, B)
351 returns false because the addition cannot overflow after A and B 260 returns false because the addition cannot overflow after A and B
352 are converted to 'int', whereas INT_ADD_WRAPV (A, B, &R) returns 261 are converted to 'int', whereas INT_ADD_WRAPV (A, B, R) returns
353 true or false depending on whether the sum fits into 'short'. 262 true or false depending on whether the sum fits into 'short'.
354 263
355 These macros are tuned for their last input argument being a constant. 264 These macros are tuned for their last input argument being a constant.
356 265
266 A, B, and *R should be integers; they need not be the same type,
267 and they need not be all signed or all unsigned.
268 However, none of the integer types should be bit-precise,
269 and *R's type should not be char, bool, or an enumeration type.
270
357 Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B, 271 Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B,
358 A % B, and A << B would overflow, respectively. */ 272 A % B, and A << B would overflow, respectively. */
359 273
@@ -361,12 +275,7 @@
361 _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW) 275 _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW)
362#define INT_SUBTRACT_OVERFLOW(a, b) \ 276#define INT_SUBTRACT_OVERFLOW(a, b) \
363 _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW) 277 _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW)
364#if _GL_HAS_BUILTIN_OVERFLOW_P 278#define INT_NEGATE_OVERFLOW(a) _GL_INT_NEGATE_OVERFLOW (a)
365# define INT_NEGATE_OVERFLOW(a) INT_SUBTRACT_OVERFLOW (0, a)
366#else
367# define INT_NEGATE_OVERFLOW(a) \
368 INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a))
369#endif
370#define INT_MULTIPLY_OVERFLOW(a, b) \ 279#define INT_MULTIPLY_OVERFLOW(a, b) \
371 _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW) 280 _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW)
372#define INT_DIVIDE_OVERFLOW(a, b) \ 281#define INT_DIVIDE_OVERFLOW(a, b) \
@@ -388,224 +297,9 @@
388 297
389/* Store the low-order bits of A + B, A - B, A * B, respectively, into *R. 298/* Store the low-order bits of A + B, A - B, A * B, respectively, into *R.
390 Return 1 if the result overflows. See above for restrictions. */ 299 Return 1 if the result overflows. See above for restrictions. */
391#if _GL_HAS_BUILTIN_ADD_OVERFLOW 300#define INT_ADD_WRAPV(a, b, r) _GL_INT_ADD_WRAPV (a, b, r)
392# define INT_ADD_WRAPV(a, b, r) __builtin_add_overflow (a, b, r) 301#define INT_SUBTRACT_WRAPV(a, b, r) _GL_INT_SUBTRACT_WRAPV (a, b, r)
393# define INT_SUBTRACT_WRAPV(a, b, r) __builtin_sub_overflow (a, b, r) 302#define INT_MULTIPLY_WRAPV(a, b, r) _GL_INT_MULTIPLY_WRAPV (a, b, r)
394#else
395# define INT_ADD_WRAPV(a, b, r) \
396 _GL_INT_OP_WRAPV (a, b, r, +, _GL_INT_ADD_RANGE_OVERFLOW)
397# define INT_SUBTRACT_WRAPV(a, b, r) \
398 _GL_INT_OP_WRAPV (a, b, r, -, _GL_INT_SUBTRACT_RANGE_OVERFLOW)
399#endif
400#if _GL_HAS_BUILTIN_MUL_OVERFLOW
401# if ((9 < __GNUC__ + (3 <= __GNUC_MINOR__) \
402 || (__GNUC__ == 8 && 4 <= __GNUC_MINOR__)) \
403 && !defined __ICC)
404# define INT_MULTIPLY_WRAPV(a, b, r) __builtin_mul_overflow (a, b, r)
405# else
406 /* Work around GCC bug 91450. */
407# define INT_MULTIPLY_WRAPV(a, b, r) \
408 ((!_GL_SIGNED_TYPE_OR_EXPR (*(r)) && EXPR_SIGNED (a) && EXPR_SIGNED (b) \
409 && _GL_INT_MULTIPLY_RANGE_OVERFLOW (a, b, 0, (__typeof__ (*(r))) -1)) \
410 ? ((void) __builtin_mul_overflow (a, b, r), 1) \
411 : __builtin_mul_overflow (a, b, r))
412# endif
413#else
414# define INT_MULTIPLY_WRAPV(a, b, r) \
415 _GL_INT_OP_WRAPV (a, b, r, *, _GL_INT_MULTIPLY_RANGE_OVERFLOW)
416#endif
417
418/* Nonzero if this compiler has GCC bug 68193 or Clang bug 25390. See:
419 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193
420 https://llvm.org/bugs/show_bug.cgi?id=25390
421 For now, assume all versions of GCC-like compilers generate bogus
422 warnings for _Generic. This matters only for compilers that
423 lack relevant builtins. */
424#if __GNUC__ || defined __clang__
425# define _GL__GENERIC_BOGUS 1
426#else
427# define _GL__GENERIC_BOGUS 0
428#endif
429
430/* Store the low-order bits of A <op> B into *R, where OP specifies
431 the operation and OVERFLOW the overflow predicate. Return 1 if the
432 result overflows. See above for restrictions. */
433#if 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS
434# define _GL_INT_OP_WRAPV(a, b, r, op, overflow) \
435 (_Generic \
436 (*(r), \
437 signed char: \
438 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
439 signed char, SCHAR_MIN, SCHAR_MAX), \
440 unsigned char: \
441 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
442 unsigned char, 0, UCHAR_MAX), \
443 short int: \
444 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
445 short int, SHRT_MIN, SHRT_MAX), \
446 unsigned short int: \
447 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
448 unsigned short int, 0, USHRT_MAX), \
449 int: \
450 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
451 int, INT_MIN, INT_MAX), \
452 unsigned int: \
453 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
454 unsigned int, 0, UINT_MAX), \
455 long int: \
456 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
457 long int, LONG_MIN, LONG_MAX), \
458 unsigned long int: \
459 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
460 unsigned long int, 0, ULONG_MAX), \
461 long long int: \
462 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
463 long long int, LLONG_MIN, LLONG_MAX), \
464 unsigned long long int: \
465 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
466 unsigned long long int, 0, ULLONG_MAX)))
467#else
468/* Store the low-order bits of A <op> B into *R, where OP specifies
469 the operation and OVERFLOW the overflow predicate. If *R is
470 signed, its type is ST with bounds SMIN..SMAX; otherwise its type
471 is UT with bounds U..UMAX. ST and UT are narrower than int.
472 Return 1 if the result overflows. See above for restrictions. */
473# if _GL_HAVE___TYPEOF__
474# define _GL_INT_OP_WRAPV_SMALLISH(a,b,r,op,overflow,st,smin,smax,ut,umax) \
475 (TYPE_SIGNED (__typeof__ (*(r))) \
476 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, st, smin, smax) \
477 : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, ut, 0, umax))
478# else
479# define _GL_INT_OP_WRAPV_SMALLISH(a,b,r,op,overflow,st,smin,smax,ut,umax) \
480 (overflow (a, b, smin, smax) \
481 ? (overflow (a, b, 0, umax) \
482 ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st), 1) \
483 : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st)) < 0) \
484 : (overflow (a, b, 0, umax) \
485 ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st)) >= 0 \
486 : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a,b,op,unsigned,st), 0)))
487# endif
488
489# define _GL_INT_OP_WRAPV(a, b, r, op, overflow) \
490 (sizeof *(r) == sizeof (signed char) \
491 ? _GL_INT_OP_WRAPV_SMALLISH (a, b, r, op, overflow, \
492 signed char, SCHAR_MIN, SCHAR_MAX, \
493 unsigned char, UCHAR_MAX) \
494 : sizeof *(r) == sizeof (short int) \
495 ? _GL_INT_OP_WRAPV_SMALLISH (a, b, r, op, overflow, \
496 short int, SHRT_MIN, SHRT_MAX, \
497 unsigned short int, USHRT_MAX) \
498 : sizeof *(r) == sizeof (int) \
499 ? (EXPR_SIGNED (*(r)) \
500 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
501 int, INT_MIN, INT_MAX) \
502 : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \
503 unsigned int, 0, UINT_MAX)) \
504 : _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow))
505# ifdef LLONG_MAX
506# define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
507 (sizeof *(r) == sizeof (long int) \
508 ? (EXPR_SIGNED (*(r)) \
509 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
510 long int, LONG_MIN, LONG_MAX) \
511 : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
512 unsigned long int, 0, ULONG_MAX)) \
513 : (EXPR_SIGNED (*(r)) \
514 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
515 long long int, LLONG_MIN, LLONG_MAX) \
516 : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \
517 unsigned long long int, 0, ULLONG_MAX)))
518# else
519# define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \
520 (EXPR_SIGNED (*(r)) \
521 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
522 long int, LONG_MIN, LONG_MAX) \
523 : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \
524 unsigned long int, 0, ULONG_MAX))
525# endif
526#endif
527
528/* Store the low-order bits of A <op> B into *R, where the operation
529 is given by OP. Use the unsigned type UT for calculation to avoid
530 overflow problems. *R's type is T, with extrema TMIN and TMAX.
531 T must be a signed integer type. Return 1 if the result overflows. */
532#define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \
533 (overflow (a, b, tmin, tmax) \
534 ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 1) \
535 : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 0))
536
537/* Return the low-order bits of A <op> B, where the operation is given
538 by OP. Use the unsigned type UT for calculation to avoid undefined
539 behavior on signed integer overflow, and convert the result to type T.
540 UT is at least as wide as T and is no narrower than unsigned int,
541 T is two's complement, and there is no padding or trap representations.
542 Assume that converting UT to T yields the low-order bits, as is
543 done in all known two's-complement C compilers. E.g., see:
544 https://gcc.gnu.org/onlinedocs/gcc/Integers-implementation.html
545
546 According to the C standard, converting UT to T yields an
547 implementation-defined result or signal for values outside T's
548 range. However, code that works around this theoretical problem
549 runs afoul of a compiler bug in Oracle Studio 12.3 x86. See:
550 https://lists.gnu.org/r/bug-gnulib/2017-04/msg00049.html
551 As the compiler bug is real, don't try to work around the
552 theoretical problem. */
553
554#define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t) \
555 ((t) ((ut) (a) op (ut) (b)))
556
557/* Return true if the numeric values A + B, A - B, A * B fall outside
558 the range TMIN..TMAX. Arguments should be integer expressions
559 without side effects. TMIN should be signed and nonpositive.
560 TMAX should be positive, and should be signed unless TMIN is zero. */
561#define _GL_INT_ADD_RANGE_OVERFLOW(a, b, tmin, tmax) \
562 ((b) < 0 \
563 ? (((tmin) \
564 ? ((EXPR_SIGNED (_GL_INT_CONVERT (a, (tmin) - (b))) || (b) < (tmin)) \
565 && (a) < (tmin) - (b)) \
566 : (a) <= -1 - (b)) \
567 || ((EXPR_SIGNED (a) ? 0 <= (a) : (tmax) < (a)) && (tmax) < (a) + (b))) \
568 : (a) < 0 \
569 ? (((tmin) \
570 ? ((EXPR_SIGNED (_GL_INT_CONVERT (b, (tmin) - (a))) || (a) < (tmin)) \
571 && (b) < (tmin) - (a)) \
572 : (b) <= -1 - (a)) \
573 || ((EXPR_SIGNED (_GL_INT_CONVERT (a, b)) || (tmax) < (b)) \
574 && (tmax) < (a) + (b))) \
575 : (tmax) < (b) || (tmax) - (b) < (a))
576#define _GL_INT_SUBTRACT_RANGE_OVERFLOW(a, b, tmin, tmax) \
577 (((a) < 0) == ((b) < 0) \
578 ? ((a) < (b) \
579 ? !(tmin) || -1 - (tmin) < (b) - (a) - 1 \
580 : (tmax) < (a) - (b)) \
581 : (a) < 0 \
582 ? ((!EXPR_SIGNED (_GL_INT_CONVERT ((a) - (tmin), b)) && (a) - (tmin) < 0) \
583 || (a) - (tmin) < (b)) \
584 : ((! (EXPR_SIGNED (_GL_INT_CONVERT (tmax, b)) \
585 && EXPR_SIGNED (_GL_INT_CONVERT ((tmax) + (b), a))) \
586 && (tmax) <= -1 - (b)) \
587 || (tmax) + (b) < (a)))
588#define _GL_INT_MULTIPLY_RANGE_OVERFLOW(a, b, tmin, tmax) \
589 ((b) < 0 \
590 ? ((a) < 0 \
591 ? (EXPR_SIGNED (_GL_INT_CONVERT (tmax, b)) \
592 ? (a) < (tmax) / (b) \
593 : ((INT_NEGATE_OVERFLOW (b) \
594 ? _GL_INT_CONVERT (b, tmax) >> (TYPE_WIDTH (+ (b)) - 1) \
595 : (tmax) / -(b)) \
596 <= -1 - (a))) \
597 : INT_NEGATE_OVERFLOW (_GL_INT_CONVERT (b, tmin)) && (b) == -1 \
598 ? (EXPR_SIGNED (a) \
599 ? 0 < (a) + (tmin) \
600 : 0 < (a) && -1 - (tmin) < (a) - 1) \
601 : (tmin) / (b) < (a)) \
602 : (b) == 0 \
603 ? 0 \
604 : ((a) < 0 \
605 ? (INT_NEGATE_OVERFLOW (_GL_INT_CONVERT (a, tmin)) && (a) == -1 \
606 ? (EXPR_SIGNED (b) ? 0 < (b) + (tmin) : -1 - (tmin) < (b) - 1) \
607 : (tmin) / (a) < (b)) \
608 : (tmax) / (b) < (a)))
609 303
610/* The following macros compute A + B, A - B, and A * B, respectively. 304/* The following macros compute A + B, A - B, and A * B, respectively.
611 If no overflow occurs, they set *R to the result and return 1; 305 If no overflow occurs, they set *R to the result and return 1;
@@ -621,6 +315,8 @@
621 315
622 A, B, and *R should be integers; they need not be the same type, 316 A, B, and *R should be integers; they need not be the same type,
623 and they need not be all signed or all unsigned. 317 and they need not be all signed or all unsigned.
318 However, none of the integer types should be bit-precise,
319 and *R's type should not be char, bool, or an enumeration type.
624 320
625 These macros work correctly on all known practical hosts, and do not rely 321 These macros work correctly on all known practical hosts, and do not rely
626 on undefined behavior due to signed arithmetic overflow. 322 on undefined behavior due to signed arithmetic overflow.
@@ -632,8 +328,8 @@
632 328
633 These macros are tuned for B being a constant. */ 329 These macros are tuned for B being a constant. */
634 330
635#define INT_ADD_OK(a, b, r) ! INT_ADD_WRAPV (a, b, r) 331#define INT_ADD_OK(a, b, r) (! INT_ADD_WRAPV (a, b, r))
636#define INT_SUBTRACT_OK(a, b, r) ! INT_SUBTRACT_WRAPV (a, b, r) 332#define INT_SUBTRACT_OK(a, b, r) (! INT_SUBTRACT_WRAPV (a, b, r))
637#define INT_MULTIPLY_OK(a, b, r) ! INT_MULTIPLY_WRAPV (a, b, r) 333#define INT_MULTIPLY_OK(a, b, r) (! INT_MULTIPLY_WRAPV (a, b, r))
638 334
639#endif /* _GL_INTPROPS_H */ 335#endif /* _GL_INTPROPS_H */