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bytes: SSE for bytes.IndexByte on amd64

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Performance on 2.8 GHz Intel Core i7:

Before:
BenchmarkIndexByte4K  1000000              2997 ns/op        1366.70 MB/s
BenchmarkIndexByte4M      500           3049772 ns/op        1375.28 MB/s
BenchmarkIndexByte64M      50          49582280 ns/op        1353.48 MB/s

After:
BenchmarkIndexByte4K 10000000               298 ns/op       13744.97 MB/s
BenchmarkIndexByte4M    10000            285993 ns/op       14665.76 MB/s
BenchmarkIndexByte64M     500           4618172 ns/op       14531.48 MB/s

R=rsc, PeterGo, r2, r
CC=golang-dev
https://golang.org/cl/2888041
This commit is contained in:
Evan Shaw 2010-11-08 17:33:53 -08:00 • committed by Rob Pike
parent e9c901dbf4
commit 49fdfe21dd
2 changed files with 137 additions and 9 deletions
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53
src/pkg/bytes/bytes_test.go
View file

@ -93,6 +93,9 @@ var indexTests = []BinOpTest{
{"abc", "b", 1},
{"abc", "c", 2},
{"abc", "x", -1},
{"barfoobarfooyyyzzzyyyzzzyyyzzzyyyxxxzzzyyy", "x", 33},
{"foofyfoobarfoobar", "y", 4},
{"oooooooooooooooooooooo", "r", -1},
}
var lastIndexTests = []BinOpTest{
@ -177,6 +180,56 @@ func TestIndexByte(t *testing.T) {
}
}
// test a larger buffer with different sizes and alignments
func TestIndexByteBig(t *testing.T) {
const n = 1024
b := make([]byte, n)
for i := 0; i < n; i++ {
// different start alignments
b1 := b[i:]
for j := 0; j < len(b1); j++ {
b1[j] = 'x'
pos := IndexByte(b1, 'x')
if pos != j {
t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
}
b1[j] = 0
pos = IndexByte(b1, 'x')
if pos != -1 {
t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
}
}
// different end alignments
b1 = b[:i]
for j := 0; j < len(b1); j++ {
b1[j] = 'x'
pos := IndexByte(b1, 'x')
if pos != j {
t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
}
b1[j] = 0
pos = IndexByte(b1, 'x')
if pos != -1 {
t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
}
}
// different start and end alignments
b1 = b[i/2 : n-(i+1)/2]
for j := 0; j < len(b1); j++ {
b1[j] = 'x'
pos := IndexByte(b1, 'x')
if pos != j {
t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
}
b1[j] = 0
pos = IndexByte(b1, 'x')
if pos != -1 {
t.Errorf("IndexByte(%q, 'x') = %v", b1, pos)
}
}
}
}
func TestIndexRune(t *testing.T) {
for _, tt := range indexRuneTests {
a := []byte(tt.a)