diff options
Diffstat (limited to 'libc/include/sys/cdefs.h')
| -rw-r--r-- | libc/include/sys/cdefs.h | 21 |
1 files changed, 3 insertions, 18 deletions
diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h index a19ce2619..e587fe713 100644 --- a/libc/include/sys/cdefs.h +++ b/libc/include/sys/cdefs.h @@ -320,27 +320,12 @@ /* Used to rename functions so that the compiler emits a call to 'x' rather than the function this was applied to. */ #define __RENAME(x) __asm__(#x) -#if __has_builtin(__builtin_umul_overflow) || __GNUC__ >= 5 -#if defined(__LP64__) -#define __size_mul_overflow(a, b, result) __builtin_umull_overflow(a, b, result) -#else -#define __size_mul_overflow(a, b, result) __builtin_umul_overflow(a, b, result) -#endif -#else -extern inline __always_inline __attribute__((gnu_inline)) -int __size_mul_overflow(__SIZE_TYPE__ a, __SIZE_TYPE__ b, __SIZE_TYPE__ *result) { - *result = a * b; - static const __SIZE_TYPE__ mul_no_overflow = 1UL << (sizeof(__SIZE_TYPE__) * 4); - return (a >= mul_no_overflow || b >= mul_no_overflow) && a > 0 && (__SIZE_TYPE__)-1 / a < b; -} -#endif - /* * Used when we need to check for overflow when multiplying x and y. This - * should only be used where __size_mul_overflow can not work, because it makes - * assumptions that __size_mul_overflow doesn't (x and y are positive, ...), + * should only be used where __builtin_umull_overflow can not work, because it makes + * assumptions that __builtin_umull_overflow doesn't (x and y are positive, ...), * *and* doesn't make use of compiler intrinsics, so it's probably slower than - * __size_mul_overflow. + * __builtin_umull_overflow. */ #define __unsafe_check_mul_overflow(x, y) ((__SIZE_TYPE__)-1 / (x) < (y)) |