erigon-pulse/common/bitutil/bitutil_test.go
David Chase 31a1f164d9 common/bitutil: use result of TestBytes to prevent dead code elimination (#19846)
Gollvm has very aggressive dead code elimination that completely
removes one of these two benchmarks.  To prevent this, use the
result of the benchmark (a boolean), and to be "fair", make the
transformation to both benchmarks.

To be reliably assured of not removing the code, "use" means
assigning to an exported global.  Non-exported globals and
//go:noinline functions are possibly subject to this optimization.
2019-07-17 10:23:43 +02:00

222 lines
6.0 KiB
Go

// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Adapted from: https://golang.org/src/crypto/cipher/xor_test.go
package bitutil
import (
"bytes"
"testing"
)
// Tests that bitwise XOR works for various alignments.
func TestXOR(t *testing.T) {
for alignP := 0; alignP < 2; alignP++ {
for alignQ := 0; alignQ < 2; alignQ++ {
for alignD := 0; alignD < 2; alignD++ {
p := make([]byte, 1023)[alignP:]
q := make([]byte, 1023)[alignQ:]
for i := 0; i < len(p); i++ {
p[i] = byte(i)
}
for i := 0; i < len(q); i++ {
q[i] = byte(len(q) - i)
}
d1 := make([]byte, 1023+alignD)[alignD:]
d2 := make([]byte, 1023+alignD)[alignD:]
XORBytes(d1, p, q)
safeXORBytes(d2, p, q)
if !bytes.Equal(d1, d2) {
t.Error("not equal", d1, d2)
}
}
}
}
}
// Tests that bitwise AND works for various alignments.
func TestAND(t *testing.T) {
for alignP := 0; alignP < 2; alignP++ {
for alignQ := 0; alignQ < 2; alignQ++ {
for alignD := 0; alignD < 2; alignD++ {
p := make([]byte, 1023)[alignP:]
q := make([]byte, 1023)[alignQ:]
for i := 0; i < len(p); i++ {
p[i] = byte(i)
}
for i := 0; i < len(q); i++ {
q[i] = byte(len(q) - i)
}
d1 := make([]byte, 1023+alignD)[alignD:]
d2 := make([]byte, 1023+alignD)[alignD:]
ANDBytes(d1, p, q)
safeANDBytes(d2, p, q)
if !bytes.Equal(d1, d2) {
t.Error("not equal")
}
}
}
}
}
// Tests that bitwise OR works for various alignments.
func TestOR(t *testing.T) {
for alignP := 0; alignP < 2; alignP++ {
for alignQ := 0; alignQ < 2; alignQ++ {
for alignD := 0; alignD < 2; alignD++ {
p := make([]byte, 1023)[alignP:]
q := make([]byte, 1023)[alignQ:]
for i := 0; i < len(p); i++ {
p[i] = byte(i)
}
for i := 0; i < len(q); i++ {
q[i] = byte(len(q) - i)
}
d1 := make([]byte, 1023+alignD)[alignD:]
d2 := make([]byte, 1023+alignD)[alignD:]
ORBytes(d1, p, q)
safeORBytes(d2, p, q)
if !bytes.Equal(d1, d2) {
t.Error("not equal")
}
}
}
}
}
// Tests that bit testing works for various alignments.
func TestTest(t *testing.T) {
for align := 0; align < 2; align++ {
// Test for bits set in the bulk part
p := make([]byte, 1023)[align:]
p[100] = 1
if TestBytes(p) != safeTestBytes(p) {
t.Error("not equal")
}
// Test for bits set in the tail part
q := make([]byte, 1023)[align:]
q[len(q)-1] = 1
if TestBytes(q) != safeTestBytes(q) {
t.Error("not equal")
}
}
}
// Benchmarks the potentially optimized XOR performance.
func BenchmarkFastXOR1KB(b *testing.B) { benchmarkFastXOR(b, 1024) }
func BenchmarkFastXOR2KB(b *testing.B) { benchmarkFastXOR(b, 2048) }
func BenchmarkFastXOR4KB(b *testing.B) { benchmarkFastXOR(b, 4096) }
func benchmarkFastXOR(b *testing.B, size int) {
p, q := make([]byte, size), make([]byte, size)
for i := 0; i < b.N; i++ {
XORBytes(p, p, q)
}
}
// Benchmarks the baseline XOR performance.
func BenchmarkBaseXOR1KB(b *testing.B) { benchmarkBaseXOR(b, 1024) }
func BenchmarkBaseXOR2KB(b *testing.B) { benchmarkBaseXOR(b, 2048) }
func BenchmarkBaseXOR4KB(b *testing.B) { benchmarkBaseXOR(b, 4096) }
func benchmarkBaseXOR(b *testing.B, size int) {
p, q := make([]byte, size), make([]byte, size)
for i := 0; i < b.N; i++ {
safeXORBytes(p, p, q)
}
}
// Benchmarks the potentially optimized AND performance.
func BenchmarkFastAND1KB(b *testing.B) { benchmarkFastAND(b, 1024) }
func BenchmarkFastAND2KB(b *testing.B) { benchmarkFastAND(b, 2048) }
func BenchmarkFastAND4KB(b *testing.B) { benchmarkFastAND(b, 4096) }
func benchmarkFastAND(b *testing.B, size int) {
p, q := make([]byte, size), make([]byte, size)
for i := 0; i < b.N; i++ {
ANDBytes(p, p, q)
}
}
// Benchmarks the baseline AND performance.
func BenchmarkBaseAND1KB(b *testing.B) { benchmarkBaseAND(b, 1024) }
func BenchmarkBaseAND2KB(b *testing.B) { benchmarkBaseAND(b, 2048) }
func BenchmarkBaseAND4KB(b *testing.B) { benchmarkBaseAND(b, 4096) }
func benchmarkBaseAND(b *testing.B, size int) {
p, q := make([]byte, size), make([]byte, size)
for i := 0; i < b.N; i++ {
safeANDBytes(p, p, q)
}
}
// Benchmarks the potentially optimized OR performance.
func BenchmarkFastOR1KB(b *testing.B) { benchmarkFastOR(b, 1024) }
func BenchmarkFastOR2KB(b *testing.B) { benchmarkFastOR(b, 2048) }
func BenchmarkFastOR4KB(b *testing.B) { benchmarkFastOR(b, 4096) }
func benchmarkFastOR(b *testing.B, size int) {
p, q := make([]byte, size), make([]byte, size)
for i := 0; i < b.N; i++ {
ORBytes(p, p, q)
}
}
// Benchmarks the baseline OR performance.
func BenchmarkBaseOR1KB(b *testing.B) { benchmarkBaseOR(b, 1024) }
func BenchmarkBaseOR2KB(b *testing.B) { benchmarkBaseOR(b, 2048) }
func BenchmarkBaseOR4KB(b *testing.B) { benchmarkBaseOR(b, 4096) }
func benchmarkBaseOR(b *testing.B, size int) {
p, q := make([]byte, size), make([]byte, size)
for i := 0; i < b.N; i++ {
safeORBytes(p, p, q)
}
}
var GloBool bool // Exported global will not be dead-code eliminated, at least not yet.
// Benchmarks the potentially optimized bit testing performance.
func BenchmarkFastTest1KB(b *testing.B) { benchmarkFastTest(b, 1024) }
func BenchmarkFastTest2KB(b *testing.B) { benchmarkFastTest(b, 2048) }
func BenchmarkFastTest4KB(b *testing.B) { benchmarkFastTest(b, 4096) }
func benchmarkFastTest(b *testing.B, size int) {
p := make([]byte, size)
a := false
for i := 0; i < b.N; i++ {
a = a != TestBytes(p)
}
GloBool = a // Use of benchmark "result" to prevent total dead code elimination.
}
// Benchmarks the baseline bit testing performance.
func BenchmarkBaseTest1KB(b *testing.B) { benchmarkBaseTest(b, 1024) }
func BenchmarkBaseTest2KB(b *testing.B) { benchmarkBaseTest(b, 2048) }
func BenchmarkBaseTest4KB(b *testing.B) { benchmarkBaseTest(b, 4096) }
func benchmarkBaseTest(b *testing.B, size int) {
p := make([]byte, size)
a := false
for i := 0; i < b.N; i++ {
a = a != safeTestBytes(p)
}
GloBool = a // Use of benchmark "result" to prevent total dead code elimination.
}