diff options
Diffstat (limited to 'base/intmath.hh')
-rw-r--r-- | base/intmath.hh | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/base/intmath.hh b/base/intmath.hh index 5ffe27103..0cf48b41b 100644 --- a/base/intmath.hh +++ b/base/intmath.hh @@ -73,7 +73,7 @@ IsPowerOf2(T n) } inline int -FloorLog2(uint32_t x) +FloorLog2(unsigned x) { assert(x > 0); @@ -89,7 +89,26 @@ FloorLog2(uint32_t x) } inline int -FloorLog2(uint64_t x) +FloorLog2(unsigned long x) +{ + assert(x > 0); + + int y = 0; + +#if defined(__LP64__) + if (x & ULL(0xffffffff00000000)) { y += 32; x >>= 32; } +#endif + if (x & 0xffff0000) { y += 16; x >>= 16; } + if (x & 0x0000ff00) { y += 8; x >>= 8; } + if (x & 0x000000f0) { y += 4; x >>= 4; } + if (x & 0x0000000c) { y += 2; x >>= 2; } + if (x & 0x00000002) { y += 1; } + + return y; +} + +inline int +FloorLog2(unsigned long long x) { assert(x > 0); @@ -106,17 +125,24 @@ FloorLog2(uint64_t x) } inline int -FloorLog2(int32_t x) +FloorLog2(int x) +{ + assert(x > 0); + return FloorLog2((unsigned)x); +} + +inline int +FloorLog2(long x) { assert(x > 0); - return FloorLog2((uint32_t)x); + return FloorLog2((unsigned long)x); } inline int -FloorLog2(int64_t x) +FloorLog2(long long x) { assert(x > 0); - return FloorLog2((uint64_t)x); + return FloorLog2((unsigned long long)x); } #if defined(__APPLE__) |