1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
//go:build go1.9
// +build go1.9
package bitset
import "math/bits"
func popcntSlice(s []uint64) uint64 {
var cnt int
for _, x := range s {
cnt += bits.OnesCount64(x)
}
return uint64(cnt)
}
func popcntMaskSlice(s, m []uint64) uint64 {
var cnt int
// this explicit check eliminates a bounds check in the loop
if len(m) < len(s) {
panic("mask slice is too short")
}
for i := range s {
cnt += bits.OnesCount64(s[i] &^ m[i])
}
return uint64(cnt)
}
func popcntAndSlice(s, m []uint64) uint64 {
var cnt int
// this explicit check eliminates a bounds check in the loop
if len(m) < len(s) {
panic("mask slice is too short")
}
for i := range s {
cnt += bits.OnesCount64(s[i] & m[i])
}
return uint64(cnt)
}
func popcntOrSlice(s, m []uint64) uint64 {
var cnt int
// this explicit check eliminates a bounds check in the loop
if len(m) < len(s) {
panic("mask slice is too short")
}
for i := range s {
cnt += bits.OnesCount64(s[i] | m[i])
}
return uint64(cnt)
}
func popcntXorSlice(s, m []uint64) uint64 {
var cnt int
// this explicit check eliminates a bounds check in the loop
if len(m) < len(s) {
panic("mask slice is too short")
}
for i := range s {
cnt += bits.OnesCount64(s[i] ^ m[i])
}
return uint64(cnt)
}
|
