diff options
| author | Martin Möhrmann <moehrmann@google.com> | 2017-04-03 22:38:09 +0200 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2017-05-10 17:02:21 +0000 |
| commit | 69972aea74de6a0397a05281475d1ca006da7bb0 (patch) | |
| tree | f2147a8505d70bd63a2f51ffe57a33a4df2a1444 /src/strings | |
| parent | 4fc498d89a1e7cef854ed95c00ce7fed817e75a4 (diff) | |
| download | go-69972aea74de6a0397a05281475d1ca006da7bb0.tar.xz | |
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 <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/strings')
| -rw-r--r-- | src/strings/strings_amd64.go | 12 |
1 files changed, 6 insertions, 6 deletions
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) |