On Thu, 27 Feb 2025 01:55:59 GMT, Xiaohong Gong <xg...@openjdk.org> wrote:
>> Nicole Xu has updated the pull request incrementally with two additional >> commits since the last revision: >> >> - 8346954: [JMH] jdk.incubator.vector.MaskedLogicOpts fails due to >> IndexOutOfBoundsException >> >> Suite MaskedLogicOpts.maskedLogicOperationsLong512() failed on both x86 >> and AArch64 with the following error: >> >> ``` >> java.lang.IndexOutOfBoundsException: Index 252 out of bounds for length >> 249 >> ``` >> >> The variable `long256_arr_idx` is misused when indexing `LongVector l2`, >> `l3`, `l4`, `l5` in function `maskedLogicOperationsLongKernel()` >> resulting in the IndexOutOfBoundsException error. On the other hand, the >> unified index for 128-bit, 256-bit and 512-bit species might not be >> proper since it leaves gaps in between when accessing the data >> for 128-bit and 256-bit species. This will unnecessarily include the >> noise due to cache misses or (on some targets) prefetching additional >> cache lines which are not usable, thereby impacting the crispness of >> microbenchmark. >> >> Hence, we improved the benchmark from several aspects, >> 1. Used sufficient number of predicated operations within the vector >> loop while minimizing the noise due to memory operations. >> 2. Modified the index computation logic which can now withstand any >> ARRAYLEN without resulting in an IOOBE. >> 3. Removed redundant vector read/writes to instance fields, thus >> eliminating significant boxing penalty which translates into throughput >> gains. >> >> Change-Id: Ie8a9d495b1ca5e36f1eae069ff70a815a2de00c0 >> - Revert "8346954: [JMH] jdk.incubator.vector.MaskedLogicOpts fails due to >> IndexOutOfBoundsException" >> >> This reverts commit 083bedec04d5ab78a420e156e74c1257ce30aee8. > > Still looks good to me! @XiaohongGong @eme64 @jatin-bhateja @PaulSandoz Thanks for your review. I'm going to integrate the patch. ------------- PR Comment: https://git.openjdk.org/jdk/pull/22963#issuecomment-2702495138
