From 69972aea74de6a0397a05281475d1ca006da7bb0 Mon Sep 17 00:00:00 2001 From: Martin Möhrmann Date: Mon, 3 Apr 2017 22:38:09 +0200 Subject: internal/cpu: new package to detect cpu features Implements detection of x86 cpu features that are used in the go standard library. Changes all standard library packages to use the new cpu package instead of using runtime internal variables to check x86 cpu features. Updates: #15403 Change-Id: I2999a10cb4d9ec4863ffbed72f4e021a1dbc4bb9 Reviewed-on: https://go-review.googlesource.com/41476 Reviewed-by: Brad Fitzpatrick Reviewed-by: Keith Randall Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot --- src/strings/strings_amd64.go | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'src/strings') diff --git a/src/strings/strings_amd64.go b/src/strings/strings_amd64.go index 33771480a6..a9c01bbf7f 100644 --- a/src/strings/strings_amd64.go +++ b/src/strings/strings_amd64.go @@ -4,19 +4,19 @@ package strings +import "internal/cpu" + //go:noescape // indexShortStr returns the index of the first instance of c in s, or -1 if c is not present in s. // indexShortStr requires 2 <= len(c) <= shortStringLen -func indexShortStr(s, c string) int // ../runtime/asm_$GOARCH.s -func supportAVX2() bool // ../runtime/asm_$GOARCH.s -func supportPOPCNT() bool // ../runtime/asm_$GOARCH.s -func countByte(s string, c byte) int // ../runtime/asm_$GOARCH.s +func indexShortStr(s, c string) int // ../runtime/asm_amd64.s +func countByte(s string, c byte) int // ../runtime/asm_amd64.s var shortStringLen int func init() { - if supportAVX2() { + if cpu.X86.HasAVX2 { shortStringLen = 63 } else { shortStringLen = 31 @@ -99,7 +99,7 @@ func Index(s, substr string) int { // Count counts the number of non-overlapping instances of substr in s. // If substr is an empty string, Count returns 1 + the number of Unicode code points in s. func Count(s, substr string) int { - if len(substr) == 1 && supportPOPCNT() { + if len(substr) == 1 && cpu.X86.HasPOPCNT { return countByte(s, byte(substr[0])) } return countGeneric(s, substr) -- cgit v1.3-5-g9baa