1 /* -*- buffer-read-only: t -*- vi: set ro: */ 2 /* DO NOT EDIT! GENERATED AUTOMATICALLY! */ 3 /* intprops.h -- properties of integer types 4 5 Copyright (C) 2001-2019 Free Software Foundation, Inc. 6 7 This program is free software: you can redistribute it and/or modify it 8 under the terms of the GNU General Public License as published 9 by the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 19 20 /* Written by Paul Eggert. */ 21 22 #ifndef _GL_INTPROPS_H 23 #define _GL_INTPROPS_H 24 25 #include <limits.h> 26 27 /* Return a value with the common real type of E and V and the value of V. 28 Do not evaluate E. */ 29 #define _GL_INT_CONVERT(e, v) ((1 ? 0 : (e)) + (v)) 30 31 /* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see 32 <https://lists.gnu.org/r/bug-gnulib/2011-05/msg00406.html>. */ 33 #define _GL_INT_NEGATE_CONVERT(e, v) ((1 ? 0 : (e)) - (v)) 34 35 /* The extra casts in the following macros work around compiler bugs, 36 e.g., in Cray C 5.0.3.0. */ 37 38 /* True if the arithmetic type T is an integer type. bool counts as 39 an integer. */ 40 #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) 41 42 /* True if the real type T is signed. */ 43 #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) 44 45 /* Return 1 if the real expression E, after promotion, has a 46 signed or floating type. Do not evaluate E. */ 47 #define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0) 48 49 50 /* Minimum and maximum values for integer types and expressions. */ 51 52 /* The width in bits of the integer type or expression T. 53 Do not evaluate T. 54 Padding bits are not supported; this is checked at compile-time below. */ 55 #define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT) 56 57 /* The maximum and minimum values for the integer type T. */ 58 #define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t)) 59 #define TYPE_MAXIMUM(t) \ 60 ((t) (! TYPE_SIGNED (t) \ 61 ? (t) -1 \ 62 : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1))) 63 64 /* The maximum and minimum values for the type of the expression E, 65 after integer promotion. E is not evaluated. */ 66 #define _GL_INT_MINIMUM(e) \ 67 (EXPR_SIGNED (e) \ 68 ? ~ _GL_SIGNED_INT_MAXIMUM (e) \ 69 : _GL_INT_CONVERT (e, 0)) 70 #define _GL_INT_MAXIMUM(e) \ 71 (EXPR_SIGNED (e) \ 72 ? _GL_SIGNED_INT_MAXIMUM (e) \ 73 : _GL_INT_NEGATE_CONVERT (e, 1)) 74 #define _GL_SIGNED_INT_MAXIMUM(e) \ 75 (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH ((e) + 0) - 2)) - 1) * 2 + 1) 76 77 /* Work around OpenVMS incompatibility with C99. */ 78 #if !defined LLONG_MAX && defined __INT64_MAX 79 # define LLONG_MAX __INT64_MAX 80 # define LLONG_MIN __INT64_MIN 81 #endif 82 83 /* This include file assumes that signed types are two's complement without 84 padding bits; the above macros have undefined behavior otherwise. 85 If this is a problem for you, please let us know how to fix it for your host. 86 This assumption is tested by the intprops-tests module. */ 87 88 /* Does the __typeof__ keyword work? This could be done by 89 'configure', but for now it's easier to do it by hand. */ 90 #if (2 <= __GNUC__ \ 91 || (1210 <= __IBMC__ && defined __IBM__TYPEOF__) \ 92 || (0x5110 <= __SUNPRO_C && !__STDC__)) 93 # define _GL_HAVE___TYPEOF__ 1 94 #else 95 # define _GL_HAVE___TYPEOF__ 0 96 #endif 97 98 /* Return 1 if the integer type or expression T might be signed. Return 0 99 if it is definitely unsigned. This macro does not evaluate its argument, 100 and expands to an integer constant expression. */ 101 #if _GL_HAVE___TYPEOF__ 102 # define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t)) 103 #else 104 # define _GL_SIGNED_TYPE_OR_EXPR(t) 1 105 #endif 106 107 /* Bound on length of the string representing an unsigned integer 108 value representable in B bits. log10 (2.0) < 146/485. The 109 smallest value of B where this bound is not tight is 2621. */ 110 #define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485) 111 112 /* Bound on length of the string representing an integer type or expression T. 113 Subtract 1 for the sign bit if T is signed, and then add 1 more for 114 a minus sign if needed. 115 116 Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 0 when its argument is 117 signed, this macro may overestimate the true bound by one byte when 118 applied to unsigned types of size 2, 4, 16, ... bytes. */ 119 #define INT_STRLEN_BOUND(t) \ 120 (INT_BITS_STRLEN_BOUND (TYPE_WIDTH (t) - _GL_SIGNED_TYPE_OR_EXPR (t)) \ 121 + _GL_SIGNED_TYPE_OR_EXPR (t)) 122 123 /* Bound on buffer size needed to represent an integer type or expression T, 124 including the terminating null. */ 125 #define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) 126 127 128 /* Range overflow checks. 129 130 The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C 131 operators might not yield numerically correct answers due to 132 arithmetic overflow. They do not rely on undefined or 133 implementation-defined behavior. Their implementations are simple 134 and straightforward, but they are a bit harder to use than the 135 INT_<op>_OVERFLOW macros described below. 136 137 Example usage: 138 139 long int i = ...; 140 long int j = ...; 141 if (INT_MULTIPLY_RANGE_OVERFLOW (i, j, LONG_MIN, LONG_MAX)) 142 printf ("multiply would overflow"); 143 else 144 printf ("product is %ld", i * j); 145 146 Restrictions on *_RANGE_OVERFLOW macros: 147 148 These macros do not check for all possible numerical problems or 149 undefined or unspecified behavior: they do not check for division 150 by zero, for bad shift counts, or for shifting negative numbers. 151 152 These macros may evaluate their arguments zero or multiple times, 153 so the arguments should not have side effects. The arithmetic 154 arguments (including the MIN and MAX arguments) must be of the same 155 integer type after the usual arithmetic conversions, and the type 156 must have minimum value MIN and maximum MAX. Unsigned types should 157 use a zero MIN of the proper type. 158 159 These macros are tuned for constant MIN and MAX. For commutative 160 operations such as A + B, they are also tuned for constant B. */ 161 162 /* Return 1 if A + B would overflow in [MIN,MAX] arithmetic. 163 See above for restrictions. */ 164 #define INT_ADD_RANGE_OVERFLOW(a, b, min, max) \ 165 ((b) < 0 \ 166 ? (a) < (min) - (b) \ 167 : (max) - (b) < (a)) 168 169 /* Return 1 if A - B would overflow in [MIN,MAX] arithmetic. 170 See above for restrictions. */ 171 #define INT_SUBTRACT_RANGE_OVERFLOW(a, b, min, max) \ 172 ((b) < 0 \ 173 ? (max) + (b) < (a) \ 174 : (a) < (min) + (b)) 175 176 /* Return 1 if - A would overflow in [MIN,MAX] arithmetic. 177 See above for restrictions. */ 178 #define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \ 179 ((min) < 0 \ 180 ? (a) < - (max) \ 181 : 0 < (a)) 182 183 /* Return 1 if A * B would overflow in [MIN,MAX] arithmetic. 184 See above for restrictions. Avoid && and || as they tickle 185 bugs in Sun C 5.11 2010/08/13 and other compilers; see 186 <https://lists.gnu.org/r/bug-gnulib/2011-05/msg00401.html>. */ 187 #define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max) \ 188 ((b) < 0 \ 189 ? ((a) < 0 \ 190 ? (a) < (max) / (b) \ 191 : (b) == -1 \ 192 ? 0 \ 193 : (min) / (b) < (a)) \ 194 : (b) == 0 \ 195 ? 0 \ 196 : ((a) < 0 \ 197 ? (a) < (min) / (b) \ 198 : (max) / (b) < (a))) 199 200 /* Return 1 if A / B would overflow in [MIN,MAX] arithmetic. 201 See above for restrictions. Do not check for division by zero. */ 202 #define INT_DIVIDE_RANGE_OVERFLOW(a, b, min, max) \ 203 ((min) < 0 && (b) == -1 && (a) < - (max)) 204 205 /* Return 1 if A % B would overflow in [MIN,MAX] arithmetic. 206 See above for restrictions. Do not check for division by zero. 207 Mathematically, % should never overflow, but on x86-like hosts 208 INT_MIN % -1 traps, and the C standard permits this, so treat this 209 as an overflow too. */ 210 #define INT_REMAINDER_RANGE_OVERFLOW(a, b, min, max) \ 211 INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max) 212 213 /* Return 1 if A << B would overflow in [MIN,MAX] arithmetic. 214 See above for restrictions. Here, MIN and MAX are for A only, and B need 215 not be of the same type as the other arguments. The C standard says that 216 behavior is undefined for shifts unless 0 <= B < wordwidth, and that when 217 A is negative then A << B has undefined behavior and A >> B has 218 implementation-defined behavior, but do not check these other 219 restrictions. */ 220 #define INT_LEFT_SHIFT_RANGE_OVERFLOW(a, b, min, max) \ 221 ((a) < 0 \ 222 ? (a) < (min) >> (b) \ 223 : (max) >> (b) < (a)) 224 225 /* True if __builtin_add_overflow (A, B, P) works when P is non-null. */ 226 #if 5 <= __GNUC__ && !defined __ICC 227 # define _GL_HAS_BUILTIN_OVERFLOW 1 228 #else 229 # define _GL_HAS_BUILTIN_OVERFLOW 0 230 #endif 231 232 /* True if __builtin_add_overflow_p (A, B, C) works. */ 233 #define _GL_HAS_BUILTIN_OVERFLOW_P (7 <= __GNUC__) 234 235 /* The _GL*_OVERFLOW macros have the same restrictions as the 236 *_RANGE_OVERFLOW macros, except that they do not assume that operands 237 (e.g., A and B) have the same type as MIN and MAX. Instead, they assume 238 that the result (e.g., A + B) has that type. */ 239 #if _GL_HAS_BUILTIN_OVERFLOW_P 240 # define _GL_ADD_OVERFLOW(a, b, min, max) \ 241 __builtin_add_overflow_p (a, b, (__typeof__ ((a) + (b))) 0) 242 # define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \ 243 __builtin_sub_overflow_p (a, b, (__typeof__ ((a) - (b))) 0) 244 # define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \ 245 __builtin_mul_overflow_p (a, b, (__typeof__ ((a) * (b))) 0) 246 #else 247 # define _GL_ADD_OVERFLOW(a, b, min, max) \ 248 ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \ 249 : (a) < 0 ? (b) <= (a) + (b) \ 250 : (b) < 0 ? (a) <= (a) + (b) \ 251 : (a) + (b) < (b)) 252 # define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \ 253 ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max) \ 254 : (a) < 0 ? 1 \ 255 : (b) < 0 ? (a) - (b) <= (a) \ 256 : (a) < (b)) 257 # define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \ 258 (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \ 259 || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max)) 260 #endif 261 #define _GL_DIVIDE_OVERFLOW(a, b, min, max) \ 262 ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \ 263 : (a) < 0 ? (b) <= (a) + (b) - 1 \ 264 : (b) < 0 && (a) + (b) <= (a)) 265 #define _GL_REMAINDER_OVERFLOW(a, b, min, max) \ 266 ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \ 267 : (a) < 0 ? (a) % (b) != ((max) - (b) + 1) % (b) \ 268 : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max)) 269 270 /* Return a nonzero value if A is a mathematical multiple of B, where 271 A is unsigned, B is negative, and MAX is the maximum value of A's 272 type. A's type must be the same as (A % B)'s type. Normally (A % 273 -B == 0) suffices, but things get tricky if -B would overflow. */ 274 #define _GL_UNSIGNED_NEG_MULTIPLE(a, b, max) \ 275 (((b) < -_GL_SIGNED_INT_MAXIMUM (b) \ 276 ? (_GL_SIGNED_INT_MAXIMUM (b) == (max) \ 277 ? (a) \ 278 : (a) % (_GL_INT_CONVERT (a, _GL_SIGNED_INT_MAXIMUM (b)) + 1)) \ 279 : (a) % - (b)) \ 280 == 0) 281 282 /* Check for integer overflow, and report low order bits of answer. 283 284 The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators 285 might not yield numerically correct answers due to arithmetic overflow. 286 The INT_<op>_WRAPV macros also store the low-order bits of the answer. 287 These macros work correctly on all known practical hosts, and do not rely 288 on undefined behavior due to signed arithmetic overflow. 289 290 Example usage, assuming A and B are long int: 291 292 if (INT_MULTIPLY_OVERFLOW (a, b)) 293 printf ("result would overflow\n"); 294 else 295 printf ("result is %ld (no overflow)\n", a * b); 296 297 Example usage with WRAPV flavor: 298 299 long int result; 300 bool overflow = INT_MULTIPLY_WRAPV (a, b, &result); 301 printf ("result is %ld (%s)\n", result, 302 overflow ? "after overflow" : "no overflow"); 303 304 Restrictions on these macros: 305 306 These macros do not check for all possible numerical problems or 307 undefined or unspecified behavior: they do not check for division 308 by zero, for bad shift counts, or for shifting negative numbers. 309 310 These macros may evaluate their arguments zero or multiple times, so the 311 arguments should not have side effects. 312 313 The WRAPV macros are not constant expressions. They support only 314 +, binary -, and *. The result type must be signed. 315 316 These macros are tuned for their last argument being a constant. 317 318 Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B, 319 A % B, and A << B would overflow, respectively. */ 320 321 #define INT_ADD_OVERFLOW(a, b) \ 322 _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW) 323 #define INT_SUBTRACT_OVERFLOW(a, b) \ 324 _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW) 325 #if _GL_HAS_BUILTIN_OVERFLOW_P 326 # define INT_NEGATE_OVERFLOW(a) INT_SUBTRACT_OVERFLOW (0, a) 327 #else 328 # define INT_NEGATE_OVERFLOW(a) \ 329 INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a)) 330 #endif 331 #define INT_MULTIPLY_OVERFLOW(a, b) \ 332 _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW) 333 #define INT_DIVIDE_OVERFLOW(a, b) \ 334 _GL_BINARY_OP_OVERFLOW (a, b, _GL_DIVIDE_OVERFLOW) 335 #define INT_REMAINDER_OVERFLOW(a, b) \ 336 _GL_BINARY_OP_OVERFLOW (a, b, _GL_REMAINDER_OVERFLOW) 337 #define INT_LEFT_SHIFT_OVERFLOW(a, b) \ 338 INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, \ 339 _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a)) 340 341 /* Return 1 if the expression A <op> B would overflow, 342 where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test, 343 assuming MIN and MAX are the minimum and maximum for the result type. 344 Arguments should be free of side effects. */ 345 #define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \ 346 op_result_overflow (a, b, \ 347 _GL_INT_MINIMUM (_GL_INT_CONVERT (a, b)), \ 348 _GL_INT_MAXIMUM (_GL_INT_CONVERT (a, b))) 349 350 /* Store the low-order bits of A + B, A - B, A * B, respectively, into *R. 351 Return 1 if the result overflows. See above for restrictions. */ 352 #define INT_ADD_WRAPV(a, b, r) \ 353 _GL_INT_OP_WRAPV (a, b, r, +, __builtin_add_overflow, INT_ADD_OVERFLOW) 354 #define INT_SUBTRACT_WRAPV(a, b, r) \ 355 _GL_INT_OP_WRAPV (a, b, r, -, __builtin_sub_overflow, INT_SUBTRACT_OVERFLOW) 356 #define INT_MULTIPLY_WRAPV(a, b, r) \ 357 _GL_INT_OP_WRAPV (a, b, r, *, __builtin_mul_overflow, INT_MULTIPLY_OVERFLOW) 358 359 /* Nonzero if this compiler has GCC bug 68193 or Clang bug 25390. See: 360 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 361 https://llvm.org/bugs/show_bug.cgi?id=25390 362 For now, assume all versions of GCC-like compilers generate bogus 363 warnings for _Generic. This matters only for older compilers that 364 lack __builtin_add_overflow. */ 365 #if __GNUC__ 366 # define _GL__GENERIC_BOGUS 1 367 #else 368 # define _GL__GENERIC_BOGUS 0 369 #endif 370 371 /* Store the low-order bits of A <op> B into *R, where OP specifies 372 the operation. BUILTIN is the builtin operation, and OVERFLOW the 373 overflow predicate. Return 1 if the result overflows. See above 374 for restrictions. */ 375 #if _GL_HAS_BUILTIN_OVERFLOW 376 # define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) builtin (a, b, r) 377 #elif 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS 378 # define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \ 379 (_Generic \ 380 (*(r), \ 381 signed char: \ 382 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ 383 signed char, SCHAR_MIN, SCHAR_MAX), \ 384 short int: \ 385 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ 386 short int, SHRT_MIN, SHRT_MAX), \ 387 int: \ 388 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ 389 int, INT_MIN, INT_MAX), \ 390 long int: \ 391 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \ 392 long int, LONG_MIN, LONG_MAX), \ 393 long long int: \ 394 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \ 395 long long int, LLONG_MIN, LLONG_MAX))) 396 #else 397 # define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \ 398 (sizeof *(r) == sizeof (signed char) \ 399 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ 400 signed char, SCHAR_MIN, SCHAR_MAX) \ 401 : sizeof *(r) == sizeof (short int) \ 402 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ 403 short int, SHRT_MIN, SHRT_MAX) \ 404 : sizeof *(r) == sizeof (int) \ 405 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ 406 int, INT_MIN, INT_MAX) \ 407 : _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow)) 408 # ifdef LLONG_MAX 409 # define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \ 410 (sizeof *(r) == sizeof (long int) \ 411 ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \ 412 long int, LONG_MIN, LONG_MAX) \ 413 : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \ 414 long long int, LLONG_MIN, LLONG_MAX)) 415 # else 416 # define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \ 417 _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \ 418 long int, LONG_MIN, LONG_MAX) 419 # endif 420 #endif 421 422 /* Store the low-order bits of A <op> B into *R, where the operation 423 is given by OP. Use the unsigned type UT for calculation to avoid 424 overflow problems. *R's type is T, with extrema TMIN and TMAX. 425 T must be a signed integer type. Return 1 if the result overflows. */ 426 #define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \ 427 (sizeof ((a) op (b)) < sizeof (t) \ 428 ? _GL_INT_OP_CALC1 ((t) (a), (t) (b), r, op, overflow, ut, t, tmin, tmax) \ 429 : _GL_INT_OP_CALC1 (a, b, r, op, overflow, ut, t, tmin, tmax)) 430 #define _GL_INT_OP_CALC1(a, b, r, op, overflow, ut, t, tmin, tmax) \ 431 ((overflow (a, b) \ 432 || (EXPR_SIGNED ((a) op (b)) && ((a) op (b)) < (tmin)) \ 433 || (tmax) < ((a) op (b))) \ 434 ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 1) \ 435 : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t), 0)) 436 437 /* Return the low-order bits of A <op> B, where the operation is given 438 by OP. Use the unsigned type UT for calculation to avoid undefined 439 behavior on signed integer overflow, and convert the result to type T. 440 UT is at least as wide as T and is no narrower than unsigned int, 441 T is two's complement, and there is no padding or trap representations. 442 Assume that converting UT to T yields the low-order bits, as is 443 done in all known two's-complement C compilers. E.g., see: 444 https://gcc.gnu.org/onlinedocs/gcc/Integers-implementation.html 445 446 According to the C standard, converting UT to T yields an 447 implementation-defined result or signal for values outside T's 448 range. However, code that works around this theoretical problem 449 runs afoul of a compiler bug in Oracle Studio 12.3 x86. See: 450 https://lists.gnu.org/r/bug-gnulib/2017-04/msg00049.html 451 As the compiler bug is real, don't try to work around the 452 theoretical problem. */ 453 454 #define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t) \ 455 ((t) ((ut) (a) op (ut) (b))) 456 457 #endif /* _GL_INTPROPS_H */ 458