From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Mon, 6 Oct 2014 22:10:51 +0000 (-0700)
Subject: strings: use fast path for IndexRune
X-Git-Tag: go1.4beta1~181
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=4731c382f6875863dc27f33088f53bce8f82c620;p=gostls13.git

strings: use fast path for IndexRune

Noticed while reviewing https://golang.org/cl/147690043/

I'd never seen anybody use IndexRune before, and
unsurprisingly it doesn't use the other fast paths in the
strings/bytes packages. IndexByte uses assembly.

Also, less code this way.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/147700043
---

diff --git a/src/strings/strings.go b/src/strings/strings.go
index 1b9df2e757..27d384983e 100644
--- a/src/strings/strings.go
+++ b/src/strings/strings.go
@@ -225,13 +225,8 @@ func LastIndex(s, sep string) int {
 // r, or -1 if rune is not present in s.
 func IndexRune(s string, r rune) int {
 	switch {
-	case r < 0x80:
-		b := byte(r)
-		for i := 0; i < len(s); i++ {
-			if s[i] == b {
-				return i
-			}
-		}
+	case r < utf8.RuneSelf:
+		return IndexByte(s, byte(r))
 	default:
 		for i, c := range s {
 			if c == r {