On Mon, 23 Aug 2021 21:48:01 GMT, TatWai Chong <github.com+78814694+tatwaich...@openjdk.org> wrote:
>> This patch implements string_compare intrinsic in SVE. >> It supports all LL, LU, UL and UU comparisons. >> >> As we haven't found an existing benchmark to measure performance impact, >> we created a benchmark derived from the test [1] for this evaluation. >> This benchmark is attached to this patch. >> >> Besides, remove the unused temporary register `vtmp3` from the existing >> match rules for StrCmp. >> >> The result below shows all varients can be benefited largely. >> Command: make exploded-test TEST="micro:StringCompareToDifferentLength" >> >> Benchmark (size) Mode Cnt Score Speedup Units >> compareToLL 24 avgt 10 1.0x ms/op >> compareToLL 36 avgt 10 1.0x ms/op >> compareToLL 72 avgt 10 1.0x ms/op >> compareToLL 128 avgt 10 1.4x ms/op >> compareToLL 256 avgt 10 1.8x ms/op >> compareToLL 512 avgt 10 2.7x ms/op >> compareToLU 24 avgt 10 1.6x ms/op >> compareToLU 36 avgt 10 1.8x ms/op >> compareToLU 72 avgt 10 2.3x ms/op >> compareToLU 128 avgt 10 3.8x ms/op >> compareToLU 256 avgt 10 4.7x ms/op >> compareToLU 512 avgt 10 6.3x ms/op >> compareToUL 24 avgt 10 1.6x ms/op >> compareToUL 36 avgt 10 1.7x ms/op >> compareToUL 72 avgt 10 2.2x ms/op >> compareToUL 128 avgt 10 3.3x ms/op >> compareToUL 256 avgt 10 4.4x ms/op >> compareToUL 512 avgt 10 6.1x ms/op >> compareToUU 24 avgt 10 1.0x ms/op >> compareToUU 36 avgt 10 1.0x ms/op >> compareToUU 72 avgt 10 1.4x ms/op >> compareToUU 128 avgt 10 2.2x ms/op >> compareToUU 256 avgt 10 2.6x ms/op >> compareToUU 512 avgt 10 3.7x ms/op >> >> [1] >> https://github.com/openjdk/jdk/blob/master/test/hotspot/jtreg/compiler/intrinsics/string/TestStringCompareToDifferentLength.java > > TatWai Chong has updated the pull request incrementally with one additional > commit since the last revision: > > Restore the removal of vtmp3 (=V2) as it is still used by the non-SVE > compare-long-strings stub. > > And remove the assertion in `string_compare` since it won't help as the > registers > used in the stub are fixed. Marked as reviewed by aph (Reviewer). ------------- PR: https://git.openjdk.java.net/jdk/pull/5129
