On Fri, 2 Feb 2024 13:54:46 GMT, Claes Redestad <redes...@openjdk.org> wrote:
> This patch streamlines and specializes various `String::indexOf` methods. > Mainly avoids the need for clamping and doing checks that are redundant in > almost all cases, moving the checks to the API boundary where they are > needed. > > This improves performance both at peak and during startup/warmup. Since > indexOf is heavily used in bootstrapping code it makes sense to slightly dial > back abstraction and delegation, which in this case also brought some benefit > to peak performance. > > Testing: tier1-3 M1 MacBook: ```Name Cnt Base Error Test Error Unit Change StringIndexOf.searchChar16LongSuccess 5 14,909 ± 3,284 14,480 ± 0,256 ns/op 1,03x (p = 0,324 ) StringIndexOf.searchChar16LongWithOffsetSuccess 5 14,715 ± 0,870 14,373 ± 0,382 ns/op 1,02x (p = 0,024 ) StringIndexOf.searchChar16MediumSuccess 5 6,611 ± 0,016 6,476 ± 0,050 ns/op 1,02x (p = 0,000*) StringIndexOf.searchChar16MediumWithOffsetSuccess 5 7,151 ± 0,026 6,884 ± 0,014 ns/op 1,04x (p = 0,000*) StringIndexOf.searchChar16ShortSuccess 5 2,667 ± 0,007 2,369 ± 0,005 ns/op 1,13x (p = 0,000*) StringIndexOf.searchChar16ShortWithOffsetSuccess 5 2,494 ± 0,112 2,102 ± 0,006 ns/op 1,19x (p = 0,000*) StringIndexOf.searchCharLongSuccess 5 5,995 ± 0,017 5,276 ± 0,017 ns/op 1,14x (p = 0,000*) StringIndexOf.searchCharLongWithOffsetSuccess 5 6,377 ± 0,118 5,735 ± 0,014 ns/op 1,11x (p = 0,000*) StringIndexOf.searchCharMediumSuccess 5 2,350 ± 0,013 1,927 ± 0,012 ns/op 1,22x (p = 0,000*) StringIndexOf.searchCharMediumWithOffsetSuccess 5 2,675 ± 0,002 2,247 ± 0,057 ns/op 1,19x (p = 0,000*) StringIndexOf.searchCharShortSuccess 5 1,719 ± 0,002 1,245 ± 0,005 ns/op 1,38x (p = 0,000*) StringIndexOf.searchCharShortWithOffsetSuccess 5 1,635 ± 0,006 1,247 ± 0,009 ns/op 1,31x (p = 0,000*) * = significant `-Xint`, M1 MacBook: ```Name Cnt Base Error Test Error Unit Change StringIndexOf.searchChar16LongSuccess 5 4683,186 ± 6,431 4482,179 ± 26,216 ns/op 1,04x (p = 0,000*) StringIndexOf.searchChar16LongWithOffsetSuccess 5 4586,540 ± 39,266 4403,976 ± 18,652 ns/op 1,04x (p = 0,000*) StringIndexOf.searchChar16MediumSuccess 5 2123,355 ± 3,885 1942,100 ± 77,042 ns/op 1,09x (p = 0,000*) StringIndexOf.searchChar16MediumWithOffsetSuccess 5 2007,646 ± 52,087 1859,545 ± 67,424 ns/op 1,08x (p = 0,000*) StringIndexOf.searchChar16ShortSuccess 5 548,599 ± 3,048 386,671 ± 60,860 ns/op 1,42x (p = 0,000*) StringIndexOf.searchChar16ShortWithOffsetSuccess 5 459,164 ± 5,782 302,377 ± 39,086 ns/op 1,52x (p = 0,000*) StringIndexOf.searchCharLongSuccess 5 908,953 ± 78,580 799,114 ± 34,290 ns/op 1,14x (p = 0,000*) StringIndexOf.searchCharLongWithOffsetSuccess 5 855,726 ± 28,357 790,690 ± 19,452 ns/op 1,08x (p = 0,000*) StringIndexOf.searchCharMediumSuccess 5 360,903 ± 3,214 262,320 ± 1,706 ns/op 1,38x (p = 0,000*) StringIndexOf.searchCharMediumWithOffsetSuccess 5 322,950 ± 5,790 268,992 ± 8,008 ns/op 1,20x (p = 0,000*) StringIndexOf.searchCharShortSuccess 5 274,718 ± 7,208 174,274 ± 3,445 ns/op 1,58x (p = 0,000*) StringIndexOf.searchCharShortWithOffsetSuccess 5 254,141 ± 11,992 186,917 ± 11,471 ns/op 1,36x (p = 0,000*) * = significant ------------- PR Comment: https://git.openjdk.org/jdk/pull/17685#issuecomment-1923869466
