diff options
Diffstat (limited to 'src/unicode/utf8/utf8.go')
| -rw-r--r-- | src/unicode/utf8/utf8.go | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/unicode/utf8/utf8.go b/src/unicode/utf8/utf8.go index 01cad1cc81..68283341d9 100644 --- a/src/unicode/utf8/utf8.go +++ b/src/unicode/utf8/utf8.go @@ -155,6 +155,20 @@ func FullRuneInString(s string) bool { // out of range, or is not the shortest possible UTF-8 encoding for the // value. No other validation is performed. func DecodeRune(p []byte) (r rune, size int) { + // Inlineable fast path for ASCII characters; see #48195. + // This implementation is weird but effective at rendering the + // function inlineable. + for _, b := range p { + if b < RuneSelf { + return rune(b), 1 + } + break + } + r, size = decodeRuneSlow(p) + return +} + +func decodeRuneSlow(p []byte) (r rune, size int) { n := len(p) if n < 1 { return RuneError, 0 @@ -203,6 +217,18 @@ func DecodeRune(p []byte) (r rune, size int) { // out of range, or is not the shortest possible UTF-8 encoding for the // value. No other validation is performed. func DecodeRuneInString(s string) (r rune, size int) { + // Inlineable fast path for ASCII characters; see #48195. + // This implementation is a bit weird but effective at rendering the + // function inlineable. + if s != "" && s[0] < RuneSelf { + return rune(s[0]), 1 + } else { + r, size = decodeRuneInStringSlow(s) + } + return +} + +func decodeRuneInStringSlow(s string) (rune, int) { n := len(s) if n < 1 { return RuneError, 0 |