diff options
Diffstat (limited to 'gl/intprops.h')
-rw-r--r-- | gl/intprops.h | 358 |
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 */ |