strings: use Builder in Repeat to avoid an allocation
name old time/op new time/op delta
Repeat/5x1-4 95.9ns ± 2% 70.1ns ± 2% -26.93% (p=0.000 n=9+10)
Repeat/5x2-4 146ns ± 3% 100ns ± 2% -31.99% (p=0.000 n=10+10)
Repeat/5x6-4 203ns ± 3% 140ns ± 4% -30.77% (p=0.000 n=10+10)
Repeat/10x1-4 139ns ± 3% 92ns ± 4% -34.08% (p=0.000 n=10+10)
Repeat/10x2-4 188ns ± 4% 122ns ± 2% -35.34% (p=0.000 n=10+10)
Repeat/10x6-4 264ns ± 5% 179ns ± 4% -32.15% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
Repeat/5x1-4 10.0B ± 0% 5.0B ± 0% -50.00% (p=0.000 n=10+10)
Repeat/5x2-4 32.0B ± 0% 16.0B ± 0% -50.00% (p=0.000 n=10+10)
Repeat/5x6-4 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.000 n=10+10)
Repeat/10x1-4 32.0B ± 0% 16.0B ± 0% -50.00% (p=0.000 n=10+10)
Repeat/10x2-4 64.0B ± 0% 32.0B ± 0% -50.00% (p=0.000 n=10+10)
Repeat/10x6-4 128B ± 0% 64B ± 0% -50.00% (p=0.000 n=10+10)
Change-Id: I6619336da636df39c560f6cc481519f48c6e8176
GitHub-Last-Rev:
4b2c73f3bfa0b3789268b9ea6e1ecdb984e8087c
GitHub-Pull-Request: golang/go#25894
Reviewed-on: https://go-review.googlesource.com/118855
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>