1 files changed, 44 insertions, 1 deletions
diff --git a/libgo/go/image/png/writer_test.go b/libgo/go/image/png/writer_test.go
index 644c4fb44b3..3116fc9ff94 100644
--- a/libgo/go/image/png/writer_test.go
+++ b/libgo/go/image/png/writer_test.go
@@ -101,6 +101,49 @@ func TestSubImage(t *testing.T) {
 	}
 }
 
+func BenchmarkEncodeGray(b *testing.B) {
+	b.StopTimer()
+	img := image.NewGray(image.Rect(0, 0, 640, 480))
+	b.SetBytes(640 * 480 * 1)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(ioutil.Discard, img)
+	}
+}
+
+func BenchmarkEncodeNRGBOpaque(b *testing.B) {
+	b.StopTimer()
+	img := image.NewNRGBA(image.Rect(0, 0, 640, 480))
+	// Set all pixels to 0xFF alpha to force opaque mode.
+	bo := img.Bounds()
+	for y := bo.Min.Y; y < bo.Max.Y; y++ {
+		for x := bo.Min.X; x < bo.Max.X; x++ {
+			img.Set(x, y, color.NRGBA{0, 0, 0, 255})
+		}
+	}
+	if !img.Opaque() {
+		b.Fatal("expected image to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(ioutil.Discard, img)
+	}
+}
+
+func BenchmarkEncodeNRGBA(b *testing.B) {
+	b.StopTimer()
+	img := image.NewNRGBA(image.Rect(0, 0, 640, 480))
+	if img.Opaque() {
+		b.Fatal("expected image not to be opaque")
+	}
+	b.SetBytes(640 * 480 * 4)
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		Encode(ioutil.Discard, img)
+	}
+}
+
 func BenchmarkEncodePaletted(b *testing.B) {
 	b.StopTimer()
 	img := image.NewPaletted(image.Rect(0, 0, 640, 480), color.Palette{
@@ -138,7 +181,7 @@ func BenchmarkEncodeRGBA(b *testing.B) {
 	b.StopTimer()
 	img := image.NewRGBA(image.Rect(0, 0, 640, 480))
 	if img.Opaque() {
-		b.Fatal("expected image to not be opaque")
+		b.Fatal("expected image not to be opaque")
 	}
 	b.SetBytes(640 * 480 * 4)
 	b.StartTimer()