From: Tom Thorogood Date: Wed, 26 Sep 2018 11:29:18 +0000 (+0000) Subject: strings: use Builder in ToUpper and ToLower X-Git-Tag: go1.12beta1~1004 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=14e7f174c1bfb80192274b049487716cdde0b4ee;p=gostls13.git strings: use Builder in ToUpper and ToLower Map was optimized to use Builder in 45c7d80832, which avoided the []byte to string converstion. This left the ToUpper and ToLower ASCII fast path with an extra allocation over Map. name old time/op new time/op delta ToUpper/#00-12 3.59ns ± 4% 3.71ns ± 1% ~ (p=0.056 n=5+5) ToUpper/ONLYUPPER-12 11.8ns ± 2% 10.5ns ± 2% -10.85% (p=0.008 n=5+5) ToUpper/abc-12 31.8ns ± 1% 25.3ns ± 1% -20.40% (p=0.008 n=5+5) ToUpper/AbC123-12 46.2ns ± 7% 31.9ns ± 8% -30.89% (p=0.008 n=5+5) ToUpper/azAZ09_-12 47.1ns ± 8% 32.6ns ± 4% -30.77% (p=0.008 n=5+5) ToUpper/longStrinGwitHmixofsmaLLandcAps-12 137ns ±15% 104ns ±11% -24.11% (p=0.008 n=5+5) ToUpper/longɐstringɐwithɐnonasciiⱯchars-12 231ns ± 1% 228ns ± 1% ~ (p=0.079 n=5+5) ToUpper/ɐɐɐɐɐ-12 207ns ± 3% 206ns ± 1% ~ (p=0.913 n=5+5) ToUpper/a\u0080\U0010ffff-12 90.8ns ± 1% 89.6ns ± 1% -1.30% (p=0.024 n=5+5) ToLower/#00-12 3.59ns ± 1% 4.26ns ± 2% +18.66% (p=0.008 n=5+5) ToLower/abc-12 6.32ns ± 1% 6.62ns ± 1% +4.72% (p=0.008 n=5+5) ToLower/AbC123-12 45.0ns ±13% 31.5ns ± 4% -29.89% (p=0.008 n=5+5) ToLower/azAZ09_-12 48.8ns ± 6% 33.2ns ± 3% -31.91% (p=0.008 n=5+5) ToLower/longStrinGwitHmixofsmaLLandcAps-12 149ns ±13% 98ns ± 8% -34.30% (p=0.008 n=5+5) ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-12 237ns ± 4% 237ns ± 2% ~ (p=0.635 n=5+5) ToLower/ⱭⱭⱭⱭⱭ-12 181ns ± 1% 181ns ± 1% ~ (p=0.762 n=5+5) ToLower/A\u0080\U0010ffff-12 90.6ns ± 1% 92.5ns ± 1% +2.05% (p=0.016 n=5+5) name old alloc/op new alloc/op delta ToUpper/#00-12 0.00B 0.00B ~ (all equal) ToUpper/ONLYUPPER-12 0.00B 0.00B ~ (all equal) ToUpper/abc-12 6.00B ± 0% 3.00B ± 0% -50.00% (p=0.008 n=5+5) ToUpper/AbC123-12 16.0B ± 0% 8.0B ± 0% -50.00% (p=0.008 n=5+5) ToUpper/azAZ09_-12 16.0B ± 0% 8.0B ± 0% -50.00% (p=0.008 n=5+5) ToUpper/longStrinGwitHmixofsmaLLandcAps-12 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.008 n=5+5) ToUpper/longɐstringɐwithɐnonasciiⱯchars-12 48.0B ± 0% 48.0B ± 0% ~ (all equal) ToUpper/ɐɐɐɐɐ-12 48.0B ± 0% 48.0B ± 0% ~ (all equal) ToUpper/a\u0080\U0010ffff-12 16.0B ± 0% 16.0B ± 0% ~ (all equal) ToLower/#00-12 0.00B 0.00B ~ (all equal) ToLower/abc-12 0.00B 0.00B ~ (all equal) ToLower/AbC123-12 16.0B ± 0% 8.0B ± 0% -50.00% (p=0.008 n=5+5) ToLower/azAZ09_-12 16.0B ± 0% 8.0B ± 0% -50.00% (p=0.008 n=5+5) ToLower/longStrinGwitHmixofsmaLLandcAps-12 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.008 n=5+5) ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-12 48.0B ± 0% 48.0B ± 0% ~ (all equal) ToLower/ⱭⱭⱭⱭⱭ-12 32.0B ± 0% 32.0B ± 0% ~ (all equal) ToLower/A\u0080\U0010ffff-12 16.0B ± 0% 16.0B ± 0% ~ (all equal) name old allocs/op new allocs/op delta ToUpper/#00-12 0.00 0.00 ~ (all equal) ToUpper/ONLYUPPER-12 0.00 0.00 ~ (all equal) ToUpper/abc-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToUpper/AbC123-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToUpper/azAZ09_-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToUpper/longStrinGwitHmixofsmaLLandcAps-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToUpper/longɐstringɐwithɐnonasciiⱯchars-12 1.00 ± 0% 1.00 ± 0% ~ (all equal) ToUpper/ɐɐɐɐɐ-12 2.00 ± 0% 2.00 ± 0% ~ (all equal) ToUpper/a\u0080\U0010ffff-12 1.00 ± 0% 1.00 ± 0% ~ (all equal) ToLower/#00-12 0.00 0.00 ~ (all equal) ToLower/abc-12 0.00 0.00 ~ (all equal) ToLower/AbC123-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToLower/azAZ09_-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToLower/longStrinGwitHmixofsmaLLandcAps-12 2.00 ± 0% 1.00 ± 0% -50.00% (p=0.008 n=5+5) ToLower/LONGⱯSTRINGⱯWITHⱯNONASCIIⱯCHARS-12 1.00 ± 0% 1.00 ± 0% ~ (all equal) ToLower/ⱭⱭⱭⱭⱭ-12 1.00 ± 0% 1.00 ± 0% ~ (all equal) ToLower/A\u0080\U0010ffff-12 1.00 ± 0% 1.00 ± 0% ~ (all equal) Updates #26304 Change-Id: I4179e21d5e60d950b925fe3ffc74b376b82812d2 GitHub-Last-Rev: 2c7c3bb75b8fb16fed5f0c8979ee9941675ed6bf GitHub-Pull-Request: golang/go#27872 Reviewed-on: https://go-review.googlesource.com/137575 Run-TryBot: Ian Lance Taylor TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick --- diff --git a/src/strings/strings.go b/src/strings/strings.go index 26aceda212..b033c38e91 100644 --- a/src/strings/strings.go +++ b/src/strings/strings.go @@ -561,15 +561,16 @@ func ToUpper(s string) string { if !hasLower { return s } - b := make([]byte, len(s)) + var b Builder + b.Grow(len(s)) for i := 0; i < len(s); i++ { c := s[i] if c >= 'a' && c <= 'z' { c -= 'a' - 'A' } - b[i] = c + b.WriteByte(c) } - return string(b) + return b.String() } return Map(unicode.ToUpper, s) } @@ -590,15 +591,16 @@ func ToLower(s string) string { if !hasUpper { return s } - b := make([]byte, len(s)) + var b Builder + b.Grow(len(s)) for i := 0; i < len(s); i++ { c := s[i] if c >= 'A' && c <= 'Z' { c += 'a' - 'A' } - b[i] = c + b.WriteByte(c) } - return string(b) + return b.String() } return Map(unicode.ToLower, s) }