main.go

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"flag"
     9  	"os"
    10  	"runtime"
    11  	"testing"
    12  
    13  	fast "./fast"
    14  	slow "./slow"
    15  )
    16  
    17  var buf = make([]byte, 1048576)
    18  
    19  func BenchmarkFastNonASCII(b *testing.B) {
    20  	for i := 0; i < b.N; i++ {
    21  		fast.NonASCII(buf, 0)
    22  	}
    23  }
    24  
    25  func BenchmarkSlowNonASCII(b *testing.B) {
    26  	for i := 0; i < b.N; i++ {
    27  		slow.NonASCII(buf, 0)
    28  	}
    29  }
    30  
    31  func main() {
    32  	testing.Init()
    33  	os.Args = []string{os.Args[0], "-test.benchtime=100ms"}
    34  	flag.Parse()
    35  
    36  	rslow := testing.Benchmark(BenchmarkSlowNonASCII)
    37  	rfast := testing.Benchmark(BenchmarkFastNonASCII)
    38  	tslow := rslow.NsPerOp()
    39  	tfast := rfast.NsPerOp()
    40  
    41  	// Optimization should be good for at least 2x, but be forgiving.
    42  	// On the ARM simulator we see closer to 1.5x.
    43  	speedup := float64(tslow) / float64(tfast)
    44  	want := 1.8
    45  	if runtime.GOARCH == "arm" {
    46  		want = 1.3
    47  	}
    48  	if speedup < want {
    49  		// TODO(rsc): doesn't work on linux-amd64 or darwin-amd64 builders, nor on
    50  		// a Lenovo x200 (linux-amd64) laptop.
    51  		// println("fast:", tfast, "slow:", tslow, "speedup:", speedup, "want:", want)
    52  		// println("not fast enough")
    53  		// os.Exit(1)
    54  	}
    55  }
    56
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