On Mon, 19 Aug 2024 04:12:56 GMT, Shaojin Wen <d...@openjdk.org> wrote:
>> I think you can have the current patch RFR (ready for review) without this >> deduplication given my concerns. We can add deduplication of frequent >> descriptors in another patch after confirming it is a net positive. > > regionMatches uses vectorizedMismatch for comparison. The length of > `Ljava/lang/Object;` is 18. In the code without intrinsic, it will exit after > two long comparisons. If there is vector128 optimization, it will exit after > one comparison, and the overhead is very small. I think you can add a case where the parameters are all these vulnerable names like `Ljava/lang/Objecq;` and repeat 8 times, and see how big a negative impact these close mismatches have. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20611#discussion_r1721217799
