diff options
Diffstat (limited to 'gnulib/import/intprops.h')
| -rw-r--r-- | gnulib/import/intprops.h | 48 |
1 files changed, 30 insertions, 18 deletions
diff --git a/gnulib/import/intprops.h b/gnulib/import/intprops.h index 2a420ac8319..d4a917f72a0 100644 --- a/gnulib/import/intprops.h +++ b/gnulib/import/intprops.h @@ -1,21 +1,20 @@ /* intprops.h -- properties of integer types - Copyright (C) 2001-2021 Free Software Foundation, Inc. + Copyright (C) 2001-2022 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 + 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 + You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ -/* Written by Paul Eggert. */ #ifndef _GL_INTPROPS_H #define _GL_INTPROPS_H @@ -133,7 +132,8 @@ 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 + and straightforward, but they are harder to use and may be less + efficient than the INT_<op>_WRAPV, INT_<op>_OK, and INT_<op>_OVERFLOW macros described below. Example usage: @@ -158,6 +158,9 @@ 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. */ @@ -226,18 +229,22 @@ /* True if __builtin_add_overflow (A, B, P) and __builtin_sub_overflow (A, B, P) work when P is non-null. */ +#ifdef __EDG__ +/* EDG-based compilers like nvc 22.1 cannot add 64-bit signed to unsigned + <https://bugs.gnu.org/53256>. */ +# define _GL_HAS_BUILTIN_ADD_OVERFLOW 0 +#elif defined __has_builtin +# define _GL_HAS_BUILTIN_ADD_OVERFLOW __has_builtin (__builtin_add_overflow) /* __builtin_{add,sub}_overflow exists but is not reliable in GCC 5.x and 6.x, see <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98269>. */ -#if 7 <= __GNUC__ && !defined __ICC +#elif 7 <= __GNUC__ # define _GL_HAS_BUILTIN_ADD_OVERFLOW 1 -#elif defined __has_builtin -# define _GL_HAS_BUILTIN_ADD_OVERFLOW __has_builtin (__builtin_add_overflow) #else # define _GL_HAS_BUILTIN_ADD_OVERFLOW 0 #endif /* True if __builtin_mul_overflow (A, B, P) works when P is non-null. */ -#ifdef __clang__ +#if defined __clang_major__ && __clang_major__ < 14 /* Work around Clang bug <https://bugs.llvm.org/show_bug.cgi?id=16404>. */ # define _GL_HAS_BUILTIN_MUL_OVERFLOW 0 #else @@ -246,9 +253,8 @@ /* True if __builtin_add_overflow_p (A, B, C) works, and similarly for __builtin_sub_overflow_p and __builtin_mul_overflow_p. */ -#if defined __clang__ || defined __ICC -/* Clang 11 lacks __builtin_mul_overflow_p, and even if it did it - would presumably run afoul of Clang bug 16404. ICC 2021.1's +#ifdef __EDG__ +/* In EDG-based compilers like ICC 2021.3 and earlier, __builtin_add_overflow_p etc. are not treated as integral constant expressions even when all arguments are. */ # define _GL_HAS_BUILTIN_OVERFLOW_P 0 @@ -339,9 +345,15 @@ arguments should not have side effects. 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. + +, 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. @@ -391,7 +403,7 @@ #if _GL_HAS_BUILTIN_MUL_OVERFLOW # if ((9 < __GNUC__ + (3 <= __GNUC_MINOR__) \ || (__GNUC__ == 8 && 4 <= __GNUC_MINOR__)) \ - && !defined __ICC) + && !defined __EDG__) # define INT_MULTIPLY_WRAPV(a, b, r) __builtin_mul_overflow (a, b, r) # else /* Work around GCC bug 91450. */ |