better alignment test

This commit is contained in:
daanx 2023-04-16 17:01:59 -07:00
parent 89e092d795
commit a8b9f2878a
2 changed files with 4 additions and 12 deletions

View File

@ -93,21 +93,13 @@ static mi_decl_noinline void* mi_heap_malloc_zero_aligned_at_fallback(mi_heap_t*
static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t size, const size_t alignment, const size_t offset, const bool zero) mi_attr_noexcept
{
// note: we don't require `size > offset`, we just guarantee that the address at offset is aligned regardless of the allocated size.
mi_assert(alignment > 0);
if mi_unlikely(alignment == 0 || !_mi_is_power_of_two(alignment)) { // require power-of-two (see <https://en.cppreference.com/w/c/memory/aligned_alloc>)
#if MI_DEBUG > 0
_mi_error_message(EOVERFLOW, "aligned allocation requires the alignment to be a power-of-two (size %zu, alignment %zu)\n", size, alignment);
#endif
return NULL;
}
/*
if mi_unlikely(alignment > MI_ALIGNMENT_MAX) { // we cannot align at a boundary larger than this (or otherwise we cannot find segment headers)
#if MI_DEBUG > 0
_mi_error_message(EOVERFLOW, "aligned allocation has a maximum alignment of %zu (size %zu, alignment %zu)\n", MI_ALIGNMENT_MAX, size, alignment);
#endif
return NULL;
}
*/
if mi_unlikely(size > PTRDIFF_MAX) { // we don't allocate more than PTRDIFF_MAX (see <https://sourceware.org/ml/libc-announce/2019/msg00001.html>)
#if MI_DEBUG > 0
_mi_error_message(EOVERFLOW, "aligned allocation request is too large (size %zu, alignment %zu)\n", size, alignment);
@ -147,9 +139,9 @@ mi_decl_nodiscard mi_decl_restrict void* mi_heap_malloc_aligned_at(mi_heap_t* he
}
mi_decl_nodiscard mi_decl_restrict void* mi_heap_malloc_aligned(mi_heap_t* heap, size_t size, size_t alignment) mi_attr_noexcept {
if (alignment == 0 || !_mi_is_power_of_two(alignment)) return NULL;
#if !MI_PADDING
// without padding, any small sized allocation is naturally aligned (see also `_mi_segment_page_start`)
if (!_mi_is_power_of_two(alignment)) return NULL;
if mi_likely(_mi_is_power_of_two(size) && size >= alignment && size <= MI_SMALL_SIZE_MAX)
#else
// with padding, we can only guarantee this for fixed alignments

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@ -56,8 +56,8 @@ int mi_posix_memalign(void** p, size_t alignment, size_t size) mi_attr_noexcept
// Note: The spec dictates we should not modify `*p` on an error. (issue#27)
// <http://man7.org/linux/man-pages/man3/posix_memalign.3.html>
if (p == NULL) return EINVAL;
if (alignment % sizeof(void*) != 0) return EINVAL; // natural alignment
if (alignment==0 || !_mi_is_power_of_two(alignment)) return EINVAL; // not a power of 2
if ((alignment % sizeof(void*)) != 0) return EINVAL; // natural alignment
// it is also required that alignment is a power of 2 and > 0; this is checked in `mi_malloc_aligned`
void* q = mi_malloc_aligned(size, alignment);
if (q==NULL && size != 0) return ENOMEM;
mi_assert_internal(((uintptr_t)q % alignment) == 0);