popcount_test.go

package popcount

import "testing"

type (
	testCase64 struct {
		n uint64
		x uint64
	}
)

var (
	cases64 = []testCase64{
		{64, 0xFFFFFFFFFFFFFFFF},
		{0, 0x0},
		{1, 0x1},
		{1, 0x8000000000000000},
		{2, 0x8000000000000001},
		{4, 0xF0},
		{7, 0xFE},
		{32, 0x123456789ABCDEF},
	}
)

func TestPopCount64(t *testing.T) {
	for _, tc := range cases64 {
		var count uint64 = Count(tc.x)
		if count != tc.n {
			t.Error("Expected", tc.n, "got", count)
		}
	}
}

type (
	testCaseSlice struct {
		n uint64
		s []uint64
	}
)

var (
	caseSlice = []testCaseSlice{
		{120, []uint64{0xFF, 0xFFFF, 0xFFFFFFFF, 0xFFFFFFFFFFFFFFFF}},
		{17, []uint64{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}},
	}
)

func TestPopCountSlice(t *testing.T) {
	for _, tc := range caseSlice {
		var count = CountSlice(tc.s)
		if count != tc.n {
			t.Error("Expected", tc.n, "got", count)
		}
	}
}

func BenchmarkGeneric(b *testing.B) {
	for i := 0; i < b.N; i++ {
		popcnt64Go(0x123456789ABCDEF)
	}
}