summaryrefslogtreecommitdiff
path: root/vendor/github.com/bits-and-blooms/bitset/popcnt.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/bits-and-blooms/bitset/popcnt.go')
-rw-r--r--vendor/github.com/bits-and-blooms/bitset/popcnt.go53
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
+}