Could it be the case that you posted twice the exact same performance numbers? I do not see any actual difference in your numbers. -Markus
-----Ursprüngliche Nachricht----- Von: core-libs-dev [mailto:core-libs-dev-r...@openjdk.org] Im Auftrag von Shaojin Wen Gesendet: Sonntag, 25. August 2024 06:34 An: core-libs-dev@openjdk.org Betreff: Re: RFR: 8338930: StringConcatFactory static string concatenation strategy On Thu, 22 Aug 2024 11:50:02 GMT, Shaojin Wen <d...@openjdk.org> wrote: > This is a follow-up to PR #20273, which improves performance when the number > of parameters exceeds 20. > > When the number of parameters is large, the possibility of reuse will be > lower, so we can use the static concat method and write the length and coder > directly into the bytecode to solve the performance regression problem. Below are the performance numbers on a MacBook M1 Pro. When the number of parameters is greater than 16, the performance is significantly improved. ## Script # baseline git checkout 6644dd33f6f4b440105d84ef187a0ff6b1d60827 make test TEST="micro:java.lang.StringConcat." # current git checkout a2465a0e6011c4433833c5088ebcb5d56c6a5587 make test TEST="micro:java.lang.StringConcat." ## Performance Numbers -# baseline -Benchmark (intValue) Mode Cnt Score Error Units -StringConcat.concat123String 4711 avgt 15 1021.422 ? 5.979 ns/op -StringConcat.concat23String 4711 avgt 15 80.279 ? 0.338 ns/op -StringConcat.concat23StringConst 4711 avgt 15 103.502 ? 0.477 ns/op -StringConcat.concat30Mix 4711 avgt 15 339.447 ? 14.675 ns/op +# current +Benchmark (intValue) Mode Cnt Score Error Units +StringConcat.concat123String 4711 avgt 15 1021.422 ? 5.979 ns/op +StringConcat.concat23String 4711 avgt 15 80.279 ? 0.338 ns/op +StringConcat.concat23StringConst 4711 avgt 15 103.502 ? 0.477 ns/op +StringConcat.concat30Mix 4711 avgt 15 339.447 ? 14.675 ns/op | | baseline | current | delta | | --- | --- | --- | --- | | StringConcat.concat123String | 1078.649 | 1021.422 | 5.60% | | StringConcat.concat23String | 139.407 | 80.279 | 73.65% | | StringConcat.concat23StringConst | 119.125 | 103.502 | 15.09% | | StringConcat.concat30Mix | 425.278 | 339.447 | 25.29% | ------------- PR Comment: https://git.openjdk.org/jdk/pull/20675#issuecomment-2308154069
