crypto/subtle: add additional benchmarks for XORBytes

Provide alignment benchmarks for XORBytes, as well as including
8192 byte blocks in the existing benchmarks. This allows us to
better evaluate performance with unaligned inputs.

Change-Id: Iad497c594c0425389ae02ca848aede5cb0ac3afd
Reviewed-on: https://go-review.googlesource.com/c/go/+/639316
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>

diff --git a/src/crypto/subtle/xor_test.go b/src/crypto/subtle/xor_test.go
index 2e2169db0aac627eff8cb176e9e7750ee41aa64f..855e54d82bb26f68159fe0e2be7282da8fa985e1 100644 (file)
--- a/src/crypto/subtle/xor_test.go
+++ b/src/crypto/subtle/xor_test.go
@@ -92,7 +92,7 @@ func BenchmarkXORBytes(b *testing.B) {
        dst := make([]byte, 1<<15)
        data0 := make([]byte, 1<<15)
        data1 := make([]byte, 1<<15)
-       sizes := []int64{1 << 3, 1 << 7, 1 << 11, 1 << 15}
+       sizes := []int64{1 << 3, 1 << 7, 1 << 11, 1 << 13, 1 << 15}
        for _, size := range sizes {
                b.Run(fmt.Sprintf("%dBytes", size), func(b *testing.B) {
                        s0 := data0[:size]
@@ -105,6 +105,26 @@ func BenchmarkXORBytes(b *testing.B) {
        }
 }
 
+func BenchmarkXORBytesAlignment(b *testing.B) {
+       dst := make([]byte, 8+1<<11)
+       data0 := make([]byte, 8+1<<11)
+       data1 := make([]byte, 8+1<<11)
+       sizes := []int64{1 << 3, 1 << 7, 1 << 11}
+       for _, size := range sizes {
+               for offset := int64(0); offset < 8; offset++ {
+                       b.Run(fmt.Sprintf("%dBytes%dOffset", size, offset), func(b *testing.B) {
+                               d := dst[offset : offset+size]
+                               s0 := data0[offset : offset+size]
+                               s1 := data1[offset : offset+size]
+                               b.SetBytes(int64(size))
+                               for i := 0; i < b.N; i++ {
+                                       XORBytes(d, s0, s1)
+                               }
+                       })
+               }
+       }
+}
+
 func mustPanic(t *testing.T, expected string, f func()) {
        t.Helper()
        defer func() {