bitset_sandbox.go

package bitset

var popcount_tab = [256]uint32 {
    0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,
    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
    3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
    1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
    3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
    2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
    3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
    3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
    4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8,
}

// alter popcount_tab type uint32|uint64 for benchmarking
func gcc_popcount_2(x uint64) uint64 {
	ret := popcount_tab[x & 0xff]
	ret += popcount_tab[(x >> 8) & 0xff]
	ret += popcount_tab[(x >> 16) & 0xff]
	ret += popcount_tab[(x >> 24) & 0xff]
	ret += popcount_tab[(x >> 32) & 0xff]
	ret += popcount_tab[(x >> 40) & 0xff]
	ret += popcount_tab[(x >> 48) & 0xff]
	ret += popcount_tab[(x >> 56) & 0xff]
	return uint64(ret)
}

func asmhamming_popcount_2(x uint64) uint64