From 7365fac2dbd01960268ee051ed03d961258d4ef4 Mon Sep 17 00:00:00 2001 From: Josh Bleecher Snyder Date: Tue, 13 Feb 2018 17:54:05 -0800 Subject: runtime: use bytes.IndexByte in findnull MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit bytes.IndexByte is heavily optimized. Use it in findnull. name old time/op new time/op delta GoString-8 65.5ns ± 1% 40.2ns ± 1% -38.62% (p=0.000 n=19+19) findnull is also used in gostringnocopy, which is used in many hot spots in the runtime. Fixes #23830 Change-Id: I2e6cb279c7d8078f8844065de684cc3567fe89d7 Reviewed-on: https://go-review.googlesource.com/97523 Run-TryBot: Josh Bleecher Snyder Reviewed-by: Brad Fitzpatrick Reviewed-by: Ian Lance Taylor TryBot-Result: Gobot Gobot --- src/runtime/string.go | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'src/runtime/string.go') diff --git a/src/runtime/string.go b/src/runtime/string.go index 5c83895995..0ea162235c 100644 --- a/src/runtime/string.go +++ b/src/runtime/string.go @@ -407,12 +407,9 @@ func findnull(s *byte) int { if s == nil { return 0 } - p := (*[maxAlloc/2 - 1]byte)(unsafe.Pointer(s)) - l := 0 - for p[l] != 0 { - l++ - } - return l + ss := stringStruct{unsafe.Pointer(s), maxAlloc/2 - 1} + t := *(*string)(unsafe.Pointer(&ss)) + return stringsIndexByte(t, 0) } func findnullw(s *uint16) int { -- cgit v1.3