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| author | Brad Fitzpatrick <bradfitz@golang.org> | 2013-02-07 16:00:06 -0800 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2013-02-07 16:00:06 -0800 |
| commit | 30a9957aacb21fef5195a43dba99669465a789e7 (patch) | |
| tree | 87acc5cdf127b2977402111ec22a9b8b9ff296e2 /src/pkg/bytes/bytes.go | |
| parent | 7594440ef134ddebc2864d207815eb325adda13f (diff) | |
| download | go-30a9957aacb21fef5195a43dba99669465a789e7.tar.xz | |
bytes: minor optimization to lastIndexFunc
Before and after:
BenchmarkTrimSpace 20000000 81.3 ns/op
BenchmarkTrimSpace 50000000 58.0 ns/op
(most whitespace trimming is ASCII whitespace)
Same optimization appeared a handful of other places
in this file, but not here.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/7305063
Diffstat (limited to 'src/pkg/bytes/bytes.go')
| -rw-r--r-- | src/pkg/bytes/bytes.go | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/pkg/bytes/bytes.go b/src/pkg/bytes/bytes.go index 31cf89ea87..6d40af4436 100644 --- a/src/pkg/bytes/bytes.go +++ b/src/pkg/bytes/bytes.go @@ -571,7 +571,10 @@ func indexFunc(s []byte, f func(r rune) bool, truth bool) int { // inverted. func lastIndexFunc(s []byte, f func(r rune) bool, truth bool) int { for i := len(s); i > 0; { - r, size := utf8.DecodeLastRune(s[0:i]) + r, size := rune(s[i-1]), 1 + if r >= utf8.RuneSelf { + r, size = utf8.DecodeLastRune(s[0:i]) + } i -= size if f(r) == truth { return i |