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Use bitwise operation to divide constant

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This commit is contained in:
YangHau 2019-07-08 15:32:28 +08:00
parent 1125271c27
commit 73cddd53d7
4 changed files with 4 additions and 4 deletions
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2
include/mimalloc-internal.h
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@ -243,7 +243,7 @@ static inline bool mi_page_all_used(mi_page_t* page) {
// is more than 7/8th of a page in use? // is more than 7/8th of a page in use?
static inline bool mi_page_mostly_used(const mi_page_t* page) { static inline bool mi_page_mostly_used(const mi_page_t* page) {
if (page==NULL) return true; if (page==NULL) return true;
uint16_t frac = page->reserved / 8U; uint16_t frac = page->reserved >> 3;
return (page->reserved - page->used + page->thread_freed < frac); return (page->reserved - page->used + page->thread_freed < frac);
} }

2
src/alloc-aligned.c
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@ -90,7 +90,7 @@ static void* mi_realloc_zero_aligned_at(void* p, size_t newsize, size_t alignmen
if (alignment <= sizeof(uintptr_t)) return _mi_realloc_zero(p,newsize,zero); if (alignment <= sizeof(uintptr_t)) return _mi_realloc_zero(p,newsize,zero);
if (p == NULL) return mi_malloc_zero_aligned_at(newsize,alignment,offset,zero); if (p == NULL) return mi_malloc_zero_aligned_at(newsize,alignment,offset,zero);
size_t size = mi_usable_size(p); size_t size = mi_usable_size(p);
if (newsize <= size && newsize >= (size - (size / 2)) if (newsize <= size && newsize >= (size - (size >> 1))
&& (((uintptr_t)p + offset) % alignment) == 0) { && (((uintptr_t)p + offset) % alignment) == 0) {
return p; // reallocation still fits, is aligned and not more than 50% waste return p; // reallocation still fits, is aligned and not more than 50% waste
} }

2
src/alloc.c
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@ -326,7 +326,7 @@ void* mi_expand(void* p, size_t newsize) mi_attr_noexcept {
void* _mi_realloc_zero(void* p, size_t newsize, bool zero) { void* _mi_realloc_zero(void* p, size_t newsize, bool zero) {
if (p == NULL) return _mi_heap_malloc_zero(mi_get_default_heap(),newsize,zero); if (p == NULL) return _mi_heap_malloc_zero(mi_get_default_heap(),newsize,zero);
size_t size = mi_usable_size(p); size_t size = mi_usable_size(p);
if (newsize <= size && newsize >= (size / 2)) { if (newsize <= size && newsize >= (size >> 1)) {
return p; // reallocation still fits and not more than 50% waste return p; // reallocation still fits and not more than 50% waste
} }
void* newp = mi_malloc(newsize); // maybe in another heap void* newp = mi_malloc(newsize); // maybe in another heap

2
src/segment.c
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@ -681,7 +681,7 @@ static mi_page_t* mi_segment_huge_page_alloc(size_t size, mi_segments_tld_t* tld
mi_page_t* _mi_segment_page_alloc(size_t block_size, mi_segments_tld_t* tld, mi_os_tld_t* os_tld) { mi_page_t* _mi_segment_page_alloc(size_t block_size, mi_segments_tld_t* tld, mi_os_tld_t* os_tld) {
mi_page_t* page; mi_page_t* page;
if (block_size < MI_SMALL_PAGE_SIZE / 8) if (block_size < MI_SMALL_PAGE_SIZE >> 3)
// smaller blocks than 8kb (assuming MI_SMALL_PAGE_SIZE == 64kb) // smaller blocks than 8kb (assuming MI_SMALL_PAGE_SIZE == 64kb)
page = mi_segment_small_page_alloc(tld,os_tld); page = mi_segment_small_page_alloc(tld,os_tld);
else if (block_size < (MI_LARGE_SIZE_MAX - sizeof(mi_segment_t))) else if (block_size < (MI_LARGE_SIZE_MAX - sizeof(mi_segment_t)))