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Remove duplicated mi_bsr and add bsr64 fastpath

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File memory.c contained duplicated mi_bsr implementation, which is
almost identical to _mi_bsr. This patch enforces the use of internal
functions _mi_bsr and ensure the availability of its 64-bit fastpath.
This commit is contained in:
Jim Huang 2019-10-20 10:01:13 +08:00
parent 25246070ae
commit e04029fb23
2 changed files with 15 additions and 14 deletions
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15
src/memory.c
View file

@ -247,24 +247,11 @@ static inline size_t mi_bsf(uintptr_t x) {
#endif
return idx;
}
static inline size_t mi_bsr(uintptr_t x) {
if (x==0) return 8*MI_INTPTR_SIZE;
DWORD idx;
#if (MI_INTPTR_SIZE==8)
_BitScanReverse64(&idx, x);
#else
_BitScanReverse(&idx, x);
#endif
return idx;
}
#elif defined(__GNUC__) || defined(__clang__)
#define MI_HAVE_BITSCAN
static inline size_t mi_bsf(uintptr_t x) {
return (x==0 ? 8*MI_INTPTR_SIZE : __builtin_ctzl(x));
}
static inline size_t mi_bsr(uintptr_t x) {
return (x==0 ? 8*MI_INTPTR_SIZE : (8*MI_INTPTR_SIZE - 1) - __builtin_clzl(x));
}
#endif
// Allocate `blocks` in a `region` at `idx` of a given `size`.
@ -310,7 +297,7 @@ static bool mi_region_alloc_blocks(mem_region_t* region, size_t idx, size_t bloc
else {
// on to the next bit range
#ifdef MI_HAVE_BITSCAN
size_t shift = (blocks == 1 ? 1 : mi_bsr(map & m) - bitidx + 1);
size_t shift = (blocks == 1 ? 1 : _mi_bsr(map & m) - bitidx + 1);
mi_assert_internal(shift > 0 && shift <= blocks);
#else
size_t shift = 1;

14
src/page-queue.c
View file

@ -59,10 +59,20 @@ static inline uint8_t mi_bsr32(uint32_t x) {
_BitScanReverse((DWORD*)&idx, x);
return (uint8_t)idx;
}
#define HAVE_MI_BSR64
static inline size_t mi_bsr64(uint64_t x) {
uint64_t idx;
_BitScanReverse64((DWORD*)&idx, x);
return (uint8_t)idx;
}
#elif defined(__GNUC__) || defined(__clang__)
static inline uint8_t mi_bsr32(uint32_t x) {
return (31 - __builtin_clz(x));
}
#define HAVE_MI_BSR64
static inline size_t mi_bsr64(uint64_t x) {
return (63 - __builtin_clzl(x));
}
#else
static inline uint8_t mi_bsr32(uint32_t x) {
// de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf>
@ -84,8 +94,12 @@ static inline uint8_t mi_bsr32(uint32_t x) {
uint8_t _mi_bsr(uintptr_t x) {
if (x == 0) return 0;
#if MI_INTPTR_SIZE==8
#ifdef HAVE_MI_BSR64
return mi_bsr64(x);
#else
uint32_t hi = (x >> 32);
return (hi == 0 ? mi_bsr32((uint32_t)x) : 32 + mi_bsr32(hi));
#endif
#elif MI_INTPTR_SIZE==4
return mi_bsr32(x);
#else