server-skynet-source-3rd-je.../include/jemalloc/internal/bit_util.h

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#ifndef JEMALLOC_INTERNAL_BIT_UTIL_H
#define JEMALLOC_INTERNAL_BIT_UTIL_H
#include "jemalloc/internal/assert.h"
#define BIT_UTIL_INLINE static inline
2014-12-09 06:40:14 +08:00
/* Sanity check. */
#if !defined(JEMALLOC_INTERNAL_FFSLL) || !defined(JEMALLOC_INTERNAL_FFSL) \
|| !defined(JEMALLOC_INTERNAL_FFS)
# error JEMALLOC_INTERNAL_FFS{,L,LL} should have been defined by configure
#endif
BIT_UTIL_INLINE unsigned
ffs_llu(unsigned long long bitmap) {
return JEMALLOC_INTERNAL_FFSLL(bitmap);
}
BIT_UTIL_INLINE unsigned
ffs_lu(unsigned long bitmap) {
return JEMALLOC_INTERNAL_FFSL(bitmap);
}
BIT_UTIL_INLINE unsigned
ffs_u(unsigned bitmap) {
return JEMALLOC_INTERNAL_FFS(bitmap);
}
BIT_UTIL_INLINE unsigned
ffs_zu(size_t bitmap) {
#if LG_SIZEOF_PTR == LG_SIZEOF_INT
return ffs_u(bitmap);
#elif LG_SIZEOF_PTR == LG_SIZEOF_LONG
return ffs_lu(bitmap);
#elif LG_SIZEOF_PTR == LG_SIZEOF_LONG_LONG
return ffs_llu(bitmap);
#else
#error No implementation for size_t ffs()
#endif
}
BIT_UTIL_INLINE unsigned
ffs_u64(uint64_t bitmap) {
#if LG_SIZEOF_LONG == 3
return ffs_lu(bitmap);
#elif LG_SIZEOF_LONG_LONG == 3
return ffs_llu(bitmap);
#else
#error No implementation for 64-bit ffs()
#endif
}
BIT_UTIL_INLINE unsigned
ffs_u32(uint32_t bitmap) {
#if LG_SIZEOF_INT == 2
return ffs_u(bitmap);
#else
#error No implementation for 32-bit ffs()
#endif
return ffs_u(bitmap);
}
BIT_UTIL_INLINE uint64_t
pow2_ceil_u64(uint64_t x) {
x--;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
x |= x >> 32;
x++;
return x;
}
BIT_UTIL_INLINE uint32_t
pow2_ceil_u32(uint32_t x) {
x--;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
x++;
return x;
}
/* Compute the smallest power of 2 that is >= x. */
BIT_UTIL_INLINE size_t
pow2_ceil_zu(size_t x) {
#if (LG_SIZEOF_PTR == 3)
return pow2_ceil_u64(x);
#else
return pow2_ceil_u32(x);
#endif
}
#if (defined(__i386__) || defined(__amd64__) || defined(__x86_64__))
BIT_UTIL_INLINE unsigned
lg_floor(size_t x) {
size_t ret;
assert(x != 0);
asm ("bsr %1, %0"
: "=r"(ret) // Outputs.
: "r"(x) // Inputs.
);
assert(ret < UINT_MAX);
return (unsigned)ret;
}
#elif (defined(_MSC_VER))
BIT_UTIL_INLINE unsigned
lg_floor(size_t x) {
unsigned long ret;
assert(x != 0);
#if (LG_SIZEOF_PTR == 3)
_BitScanReverse64(&ret, x);
#elif (LG_SIZEOF_PTR == 2)
_BitScanReverse(&ret, x);
#else
# error "Unsupported type size for lg_floor()"
#endif
assert(ret < UINT_MAX);
return (unsigned)ret;
}
#elif (defined(JEMALLOC_HAVE_BUILTIN_CLZ))
BIT_UTIL_INLINE unsigned
lg_floor(size_t x) {
assert(x != 0);
#if (LG_SIZEOF_PTR == LG_SIZEOF_INT)
return ((8 << LG_SIZEOF_PTR) - 1) - __builtin_clz(x);
#elif (LG_SIZEOF_PTR == LG_SIZEOF_LONG)
return ((8 << LG_SIZEOF_PTR) - 1) - __builtin_clzl(x);
#else
# error "Unsupported type size for lg_floor()"
#endif
}
#else
BIT_UTIL_INLINE unsigned
lg_floor(size_t x) {
assert(x != 0);
x |= (x >> 1);
x |= (x >> 2);
x |= (x >> 4);
x |= (x >> 8);
x |= (x >> 16);
#if (LG_SIZEOF_PTR == 3)
x |= (x >> 32);
#endif
if (x == SIZE_T_MAX) {
return (8 << LG_SIZEOF_PTR) - 1;
}
x++;
return ffs_zu(x) - 2;
}
#endif
#undef BIT_UTIL_INLINE
#endif /* JEMALLOC_INTERNAL_BIT_UTIL_H */