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| author | Ilya Tocar <ilya.tocar@intel.com> | 2017-09-12 15:31:09 -0500 |
|---|---|---|
| committer | Ilya Tocar <ilya.tocar@intel.com> | 2017-09-12 21:32:50 +0000 |
| commit | bc8bb5b27a5abe48fbfc79ae4a1ce4c87ca90bbc (patch) | |
| tree | c17b73091936a27551c1a9f985340f109f40e81f /src/unicode | |
| parent | 6237ab2c3155ed4c4fa064d1f0cb4f81eda10be1 (diff) | |
| download | go-bc8bb5b27a5abe48fbfc79ae4a1ce4c87ca90bbc.tar.gz go-bc8bb5b27a5abe48fbfc79ae4a1ce4c87ca90bbc.zip | |
unicode: speed-up is16/is32
Avoid division in common case. There are 5438 ranges in unicode/tables.go
4110 of them have stride 1.
Stride 1 case got significantly faster. Other stride is a bit slower.
Measured by
import (
"testing"
"unicode"
)
func BenchmarkDiv1(b *testing.B) {
rtb := &unicode.RangeTable{
R16: []unicode.Range16{
{0xa800, 0xdfff, 1}, // or 3
},
}
for i := 0; i < b.N; i++ {
unicode.Is(rtb, rune(0xc700))
}
}
Div1-6 15.6ns ± 1% 9.9ns ± 1% -36.54% (p=0.000 n=10+10)
Div3-6 15.5ns ± 1% 16.1ns ± 1% +3.67% (p=0.000 n=10+10)
Helps a bit with xml parsing from issue #21823
XMLsax-6 30.9s ± 0% 29.6s ± 0% -4.15% (p=0.000 n=10+9)
Change-Id: Ibac1a91d7b9474d0c134b0add83e56caa62daa20
Reviewed-on: https://go-review.googlesource.com/63390
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/unicode')
| -rw-r--r-- | src/unicode/letter.go | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/unicode/letter.go b/src/unicode/letter.go index 90b0b414da..4d9fc67165 100644 --- a/src/unicode/letter.go +++ b/src/unicode/letter.go @@ -97,7 +97,7 @@ func is16(ranges []Range16, r uint16) bool { return false } if r <= range_.Hi { - return (r-range_.Lo)%range_.Stride == 0 + return range_.Stride == 1 || (r-range_.Lo)%range_.Stride == 0 } } return false @@ -110,7 +110,7 @@ func is16(ranges []Range16, r uint16) bool { m := lo + (hi-lo)/2 range_ := &ranges[m] if range_.Lo <= r && r <= range_.Hi { - return (r-range_.Lo)%range_.Stride == 0 + return range_.Stride == 1 || (r-range_.Lo)%range_.Stride == 0 } if r < range_.Lo { hi = m @@ -130,7 +130,7 @@ func is32(ranges []Range32, r uint32) bool { return false } if r <= range_.Hi { - return (r-range_.Lo)%range_.Stride == 0 + return range_.Stride == 1 || (r-range_.Lo)%range_.Stride == 0 } } return false @@ -143,7 +143,7 @@ func is32(ranges []Range32, r uint32) bool { m := lo + (hi-lo)/2 range_ := ranges[m] if range_.Lo <= r && r <= range_.Hi { - return (r-range_.Lo)%range_.Stride == 0 + return range_.Stride == 1 || (r-range_.Lo)%range_.Stride == 0 } if r < range_.Lo { hi = m |