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. 4 5 /* 6 Deprecated: benchcmp is deprecated in favor of benchstat: golang.org/x/perf/cmd/benchstat 7 8 The benchcmp command displays performance changes between benchmarks. 9 10 Benchcmp parses the output of two 'go test' benchmark runs, 11 correlates the results per benchmark, and displays the deltas. 12 13 To measure the performance impact of a change, use 'go test' 14 to run benchmarks before and after the change: 15 16 go test -run=NONE -bench=. ./... > old.txt 17 # make changes 18 go test -run=NONE -bench=. ./... > new.txt 19 20 Then feed the benchmark results to benchcmp: 21 22 benchcmp old.txt new.txt 23 24 Benchcmp will summarize and display the performance changes, 25 in a format like this: 26 27 $ benchcmp old.txt new.txt 28 benchmark old ns/op new ns/op delta 29 BenchmarkConcat 523 68.6 -86.88% 30 31 benchmark old allocs new allocs delta 32 BenchmarkConcat 3 1 -66.67% 33 34 benchmark old bytes new bytes delta 35 BenchmarkConcat 80 48 -40.00% 36 */ 37 package main // import "golang.org/x/tools/cmd/benchcmp" 38