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| author | Ilya Tocar <ilya.tocar@intel.com> | 2016-04-28 17:39:55 +0300 |
|---|---|---|
| committer | Ilya Tocar <ilya.tocar@intel.com> | 2016-09-07 10:43:13 +0000 |
| commit | 0cff219c1279cb76f042004bffcefba0a169cb67 (patch) | |
| tree | a929e6aaf14d9307523a72b278d053854676d7bb /src/bytes | |
| parent | 83c73a85db84a04c8e60e52cfa348fc6b675fbf7 (diff) | |
| download | go-0cff219c1279cb76f042004bffcefba0a169cb67.tar.xz | |
strings: use AVX2 for Index if available
IndexHard4-4 1.50ms ± 2% 0.71ms ± 0% -52.36% (p=0.000 n=20+19)
This also fixes a bug, that caused a string of length 16 to use
two 8-byte comparisons instead of one 16-byte. And adds a test for
cases when partial_match fails.
Change-Id: I1ee8fc4e068bb36c95c45de78f067c822c0d9df0
Reviewed-on: https://go-review.googlesource.com/22551
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/bytes')
| -rw-r--r-- | src/bytes/bytes_amd64.go | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/bytes/bytes_amd64.go b/src/bytes/bytes_amd64.go index b683e6721c..198962322a 100644 --- a/src/bytes/bytes_amd64.go +++ b/src/bytes/bytes_amd64.go @@ -9,7 +9,17 @@ package bytes // 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 []byte) int // ../runtime/asm_$GOARCH.s -const shortStringLen = 31 +func supportAVX2() bool // ../runtime/asm_$GOARCH.s + +var shortStringLen int + +func init() { + if supportAVX2() { + shortStringLen = 63 + } else { + shortStringLen = 31 + } +} // Index returns the index of the first instance of sep in s, or -1 if sep is not present in s. func Index(s, sep []byte) int { |