On Tue, 3 Aug 2021 13:33:07 GMT, Wang Huang <whu...@openjdk.org> wrote:
>> Dear all, >> Can you do me a favor to review this patch. This patch use `ldp` to >> implement String.compareTo. >> >> * We add a JMH test case >> * Here is the result of this test case >> >> Benchmark |(size)| Mode| Cnt|Score | Error |Units >> ---------------------------------|------|-----|----|------|--------|----- >> StringCompare.compareLL | 64 | avgt| 5 |7.992 | ± 0.005|us/op >> StringCompare.compareLL | 72 | avgt| 5 |15.029| ± 0.006|us/op >> StringCompare.compareLL | 80 | avgt| 5 |14.655| ± 0.011|us/op >> StringCompare.compareLL | 91 | avgt| 5 |16.363| ± 0.12 |us/op >> StringCompare.compareLL | 101 | avgt| 5 |16.966| ± 0.007|us/op >> StringCompare.compareLL | 121 | avgt| 5 |19.276| ± 0.006|us/op >> StringCompare.compareLL | 181 | avgt| 5 |19.002| ± 0.417|us/op >> StringCompare.compareLL | 256 | avgt| 5 |24.707| ± 0.041|us/op >> StringCompare.compareLLWithLdp| 64 | avgt| 5 |8.001 | ± >> 0.121|us/op >> StringCompare.compareLLWithLdp| 72 | avgt| 5 |11.573| ± 0.003|us/op >> StringCompare.compareLLWithLdp| 80 | avgt| 5 |6.861 | ± 0.004|us/op >> StringCompare.compareLLWithLdp| 91 | avgt| 5 |12.774| ± 0.201|us/op >> StringCompare.compareLLWithLdp| 101 | avgt| 5 |8.691 | ± 0.004|us/op >> StringCompare.compareLLWithLdp| 121 | avgt| 5 |11.091| ± 1.342|us/op >> StringCompare.compareLLWithLdp| 181 | avgt| 5 |14.64 | ± 0.581|us/op >> StringCompare.compareLLWithLdp| 256 | avgt| 5 |25.879| ± 1.775|us/op >> StringCompare.compareUU | 64 | avgt| 5 |13.476| ± 0.01 |us/op >> StringCompare.compareUU | 72 | avgt| 5 |15.078| ± 0.006|us/op >> StringCompare.compareUU | 80 | avgt| 5 |23.512| ± 0.011|us/op >> StringCompare.compareUU | 91 | avgt| 5 |24.284| ± 0.008|us/op >> StringCompare.compareUU | 101 | avgt| 5 |20.707| ± 0.017|us/op >> StringCompare.compareUU | 121 | avgt| 5 |29.302| ± 0.011|us/op >> StringCompare.compareUU | 181 | avgt| 5 |39.31 | ± >> 0.016|us/op >> StringCompare.compareUU | 256 | avgt| 5 |54.592| ± 0.392|us/op >> StringCompare.compareUUWithLdp| 64 | avgt| 5 |16.389| ± 0.008|us/op >> StringCompare.compareUUWithLdp| 72 | avgt| 5 |10.71 | ± 0.158|us/op >> StringCompare.compareUUWithLdp| 80 | avgt| 5 |11.488| ± 0.024|us/op >> StringCompare.compareUUWithLdp| 91 | avgt| 5 |13.412| ± 0.006|us/op >> StringCompare.compareUUWithLdp| 101 | avgt| 5 |16.245| ± 0.434|us/op >> StringCompare.compareUUWithLdp| 121 | avgt| 5 |16.597| ± 0.016|us/op >> StringCompare.compareUUWithLdp| 181 | avgt| 5 |27.373| ± 0.017|us/op >> StringCompare.compareUUWithLdp| 256 | avgt| 5 |41.74 | ± 3.5 |us/op >> >> From this table, we can see that in most cases, our patch is better than old >> one. >> >> Thank you for your review. Any suggestions are welcome. > > Wang Huang has updated the pull request with a new target base due to a merge > or a rebase. The incremental webrev excludes the unrelated changes brought in > by the merge/rebase. The pull request contains six additional commits since > the last revision: > > - fix bugs > - Merge branch 'master' of https://gitee.com/ustc-wh/jdk into JDK-8268231 > - fix style and add unalign test case > - refact codes > - draft of refactor > - 8268231: Aarch64: Use ldp in intrinsics for String.compareTo Please provide the updated benchmark results for this version. Are you able to test it on several different machines? src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 4892: > 4890: __ cmp(tmp1, tmp2); > 4891: __ ccmp(tmp1h, tmp2h, 0, Assembler::EQ); > 4892: __ br(__ NE, DIFF); The line above uses `Assembler::EQ` for the condition code but this line uses `__ NE`. Better to be consistent and use `Assembler::` everywhere. ------------- PR: https://git.openjdk.java.net/jdk/pull/4722
