1 // Copyright 2014 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.
15 "golang.org/x/tools/benchmark/parse"
19 changedOnly = flag.Bool("changed", false, "show only benchmarks that have changed")
20 magSort = flag.Bool("mag", false, "sort benchmarks by magnitude of change")
21 best = flag.Bool("best", false, "compare best times from old and new")
25 Each input file should be from:
26 go test -run=NONE -bench=. > [old,new].txt
28 Benchcmp compares old and new for each benchmark.
30 If -test.benchmem=true is added to the "go test" command
31 benchcmp will also compare memory allocations.
35 fmt.Fprintf(os.Stderr, "benchcmp is deprecated in favor of benchstat: https://pkg.go.dev/golang.org/x/perf/cmd/benchstat\n")
37 fmt.Fprintf(os.Stderr, "usage: %s old.txt new.txt\n\n", os.Args[0])
39 fmt.Fprint(os.Stderr, usageFooter)
47 before := parseFile(flag.Arg(0))
48 after := parseFile(flag.Arg(1))
50 cmps, warnings := Correlate(before, after)
52 for _, warn := range warnings {
53 fmt.Fprintln(os.Stderr, warn)
57 fatal("benchcmp: no repeated benchmarks")
60 w := new(tabwriter.Writer)
61 w.Init(os.Stdout, 0, 0, 5, ' ', 0)
64 var header bool // Has the header has been displayed yet for a given block?
67 sort.Sort(ByDeltaNsPerOp(cmps))
69 sort.Sort(ByParseOrder(cmps))
71 for _, cmp := range cmps {
72 if !cmp.Measured(parse.NsPerOp) {
75 if delta := cmp.DeltaNsPerOp(); !*changedOnly || delta.Changed() {
77 fmt.Fprint(w, "benchmark\told ns/op\tnew ns/op\tdelta\n")
80 fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", cmp.Name(), formatNs(cmp.Before.NsPerOp), formatNs(cmp.After.NsPerOp), delta.Percent())
86 sort.Sort(ByDeltaMBPerS(cmps))
88 for _, cmp := range cmps {
89 if !cmp.Measured(parse.MBPerS) {
92 if delta := cmp.DeltaMBPerS(); !*changedOnly || delta.Changed() {
94 fmt.Fprint(w, "\nbenchmark\told MB/s\tnew MB/s\tspeedup\n")
97 fmt.Fprintf(w, "%s\t%.2f\t%.2f\t%s\n", cmp.Name(), cmp.Before.MBPerS, cmp.After.MBPerS, delta.Multiple())
103 sort.Sort(ByDeltaAllocsPerOp(cmps))
105 for _, cmp := range cmps {
106 if !cmp.Measured(parse.AllocsPerOp) {
109 if delta := cmp.DeltaAllocsPerOp(); !*changedOnly || delta.Changed() {
111 fmt.Fprint(w, "\nbenchmark\told allocs\tnew allocs\tdelta\n")
114 fmt.Fprintf(w, "%s\t%d\t%d\t%s\n", cmp.Name(), cmp.Before.AllocsPerOp, cmp.After.AllocsPerOp, delta.Percent())
120 sort.Sort(ByDeltaAllocedBytesPerOp(cmps))
122 for _, cmp := range cmps {
123 if !cmp.Measured(parse.AllocedBytesPerOp) {
126 if delta := cmp.DeltaAllocedBytesPerOp(); !*changedOnly || delta.Changed() {
128 fmt.Fprint(w, "\nbenchmark\told bytes\tnew bytes\tdelta\n")
131 fmt.Fprintf(w, "%s\t%d\t%d\t%s\n", cmp.Name(), cmp.Before.AllocedBytesPerOp, cmp.After.AllocedBytesPerOp, cmp.DeltaAllocedBytesPerOp().Percent())
136 func fatal(msg interface{}) {
137 fmt.Fprintln(os.Stderr, msg)
141 func parseFile(path string) parse.Set {
142 f, err := os.Open(path)
147 bb, err := parse.ParseSet(f)
157 func selectBest(bs parse.Set) {
158 for name, bb := range bs {
164 for _, b := range bb {
165 if b.NsPerOp < best.NsPerOp {
170 bs[name] = []*parse.Benchmark{best}
174 // formatNs formats ns measurements to expose a useful amount of
175 // precision. It mirrors the ns precision logic of testing.B.
176 func formatNs(ns float64) string {
184 return strconv.FormatFloat(ns, 'f', prec, 64)