1 files changed, 116 insertions, 0 deletions
diff --git a/pkg/bits/uint64_test.go b/pkg/bits/uint64_test.go
new file mode 100644
index 000000000..906017e1a
--- /dev/null
+++ b/pkg/bits/uint64_test.go
@@ -0,0 +1,116 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package bits
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestTrailingZeros64(t *testing.T) {
+	for i := 0; i <= 64; i++ {
+		n := uint64(1) << uint(i)
+		if got, want := TrailingZeros64(n), i; got != want {
+			t.Errorf("TrailingZeros64(%#x): got %d, wanted %d", n, got, want)
+		}
+	}
+
+	for i := 0; i < 64; i++ {
+		n := ^uint64(0) << uint(i)
+		if got, want := TrailingZeros64(n), i; got != want {
+			t.Errorf("TrailingZeros64(%#x): got %d, wanted %d", n, got, want)
+		}
+	}
+
+	for i := 0; i < 64; i++ {
+		n := ^uint64(0) >> uint(i)
+		if got, want := TrailingZeros64(n), 0; got != want {
+			t.Errorf("TrailingZeros64(%#x): got %d, wanted %d", n, got, want)
+		}
+	}
+}
+
+func TestMostSignificantOne64(t *testing.T) {
+	for i := 0; i <= 64; i++ {
+		n := uint64(1) << uint(i)
+		if got, want := MostSignificantOne64(n), i; got != want {
+			t.Errorf("MostSignificantOne64(%#x): got %d, wanted %d", n, got, want)
+		}
+	}
+
+	for i := 0; i < 64; i++ {
+		n := ^uint64(0) >> uint(i)
+		if got, want := MostSignificantOne64(n), 63-i; got != want {
+			t.Errorf("MostSignificantOne64(%#x): got %d, wanted %d", n, got, want)
+		}
+	}
+
+	for i := 0; i < 64; i++ {
+		n := ^uint64(0) << uint(i)
+		if got, want := MostSignificantOne64(n), 63; got != want {
+			t.Errorf("MostSignificantOne64(%#x): got %d, wanted %d", n, got, want)
+		}
+	}
+}
+
+func TestForEachSetBit64(t *testing.T) {
+	for _, want := range [][]int{
+		{},
+		{0},
+		{1},
+		{63},
+		{0, 1},
+		{1, 3, 5},
+		{0, 63},
+	} {
+		n := Mask64(want...)
+		// "Slice values are deeply equal when ... they are both nil or both
+		// non-nil ..."
+		got := make([]int, 0)
+		ForEachSetBit64(n, func(i int) {
+			got = append(got, i)
+		})
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("ForEachSetBit64(%#x): iterated bits %v, wanted %v", n, got, want)
+		}
+	}
+}
+
+func TestIsOn(t *testing.T) {
+	type spec struct {
+		mask uint64
+		bits uint64
+		any  bool
+		all  bool
+	}
+	for _, s := range []spec{
+		{Mask64(0), Mask64(0), true, true},
+		{Mask64(63), Mask64(63), true, true},
+		{Mask64(0), Mask64(1), false, false},
+		{Mask64(0), Mask64(0, 1), true, false},
+
+		{Mask64(1, 63), Mask64(1), true, true},
+		{Mask64(1, 63), Mask64(1, 63), true, true},
+		{Mask64(1, 63), Mask64(0, 1, 63), true, false},
+		{Mask64(1, 63), Mask64(0, 62), false, false},
+	} {
+		if ok := IsAnyOn64(s.mask, s.bits); ok != s.any {
+			t.Errorf("IsAnyOn(%#x, %#x) = %v, wanted: %v", s.mask, s.bits, ok, s.any)
+		}
+		if ok := IsOn64(s.mask, s.bits); ok != s.all {
+			t.Errorf("IsOn(%#x, %#x) = %v, wanted: %v", s.mask, s.bits, ok, s.all)
+		}
+	}
+}