diff options
Diffstat (limited to 'vendor/github.com/bits-and-blooms/bitset/popcnt.go')
-rw-r--r-- | vendor/github.com/bits-and-blooms/bitset/popcnt.go | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/vendor/github.com/bits-and-blooms/bitset/popcnt.go b/vendor/github.com/bits-and-blooms/bitset/popcnt.go new file mode 100644 index 000000000..76577a838 --- /dev/null +++ b/vendor/github.com/bits-and-blooms/bitset/popcnt.go @@ -0,0 +1,53 @@ +package bitset + +// bit population count, take from +// https://code.google.com/p/go/issues/detail?id=4988#c11 +// credit: https://code.google.com/u/arnehormann/ +func popcount(x uint64) (n uint64) { + x -= (x >> 1) & 0x5555555555555555 + x = (x>>2)&0x3333333333333333 + x&0x3333333333333333 + x += x >> 4 + x &= 0x0f0f0f0f0f0f0f0f + x *= 0x0101010101010101 + return x >> 56 +} + +func popcntSliceGo(s []uint64) uint64 { + cnt := uint64(0) + for _, x := range s { + cnt += popcount(x) + } + return cnt +} + +func popcntMaskSliceGo(s, m []uint64) uint64 { + cnt := uint64(0) + for i := range s { + cnt += popcount(s[i] &^ m[i]) + } + return cnt +} + +func popcntAndSliceGo(s, m []uint64) uint64 { + cnt := uint64(0) + for i := range s { + cnt += popcount(s[i] & m[i]) + } + return cnt +} + +func popcntOrSliceGo(s, m []uint64) uint64 { + cnt := uint64(0) + for i := range s { + cnt += popcount(s[i] | m[i]) + } + return cnt +} + +func popcntXorSliceGo(s, m []uint64) uint64 { + cnt := uint64(0) + for i := range s { + cnt += popcount(s[i] ^ m[i]) + } + return cnt +} |