From 0253580a75decdaf22b6abce60d8265b2adb7dea Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 21 Dec 2018 09:49:37 -0200 Subject: Replace check_mul_overflow_size_t with __builtin_mul_overflow Checked on x86_64-linux-gnu and i686-linux-gnu. * malloc/alloc_buffer_alloc_array.c (__libc_alloc_buffer_alloc_array): Use __builtin_mul_overflow in place of check_mul_overflow_size_t. * malloc/dynarray_emplace_enlarge.c (__libc_dynarray_emplace_enlarge): Likewise. * malloc/dynarray_resize.c (__libc_dynarray_resize): Likewise. * malloc/reallocarray.c (__libc_reallocarray): Likewise. * malloc/malloc-internal.h (check_mul_overflow_size_t): Remove function. * support/blob_repeat.c (check_mul_overflow_size_t, (minimum_stride_size, support_blob_repeat_allocate): Likewise. --- support/blob_repeat.c | 26 +++----------------------- 1 file changed, 3 insertions(+), 23 deletions(-) (limited to 'support/blob_repeat.c') diff --git a/support/blob_repeat.c b/support/blob_repeat.c index 718846d..daa1b7f 100644 --- a/support/blob_repeat.c +++ b/support/blob_repeat.c @@ -34,26 +34,6 @@ optimization because mappings carry a lot of overhead. */ static const size_t maximum_small_size = 4 * 1024 * 1024; -/* Set *RESULT to LEFT * RIGHT. Return true if the multiplication - overflowed. See . */ -static inline bool -check_mul_overflow_size_t (size_t left, size_t right, size_t *result) -{ -#if __GNUC__ >= 5 - return __builtin_mul_overflow (left, right, result); -#else - /* size_t is unsigned so the behavior on overflow is defined. */ - *result = left * right; - size_t half_size_t = ((size_t) 1) << (8 * sizeof (size_t) / 2); - if (__glibc_unlikely ((left | right) >= half_size_t)) - { - if (__glibc_unlikely (right != 0 && *result / right != left)) - return true; - } - return false; -#endif -} - /* Internal helper for fill. */ static void fill0 (char *target, const char *element, size_t element_size, @@ -138,8 +118,8 @@ minimum_stride_size (size_t page_size, size_t element_size) common multiple, it appears only once. Therefore, shift one factor. */ size_t multiple; - if (check_mul_overflow_size_t (page_size >> common_zeros, element_size, - &multiple)) + if (__builtin_mul_overflow (page_size >> common_zeros, element_size, + &multiple)) return 0; return multiple; } @@ -275,7 +255,7 @@ support_blob_repeat_allocate (const void *element, size_t element_size, size_t count) { size_t total_size; - if (check_mul_overflow_size_t (element_size, count, &total_size)) + if (__builtin_mul_overflow (element_size, count, &total_size)) { errno = EOVERFLOW; return (struct support_blob_repeat) { 0 }; -- cgit v1.1