On Fri, 19 Apr 2024 16:25:28 GMT, Scott Gibbons <sgibb...@openjdk.org> wrote:
>> This code makes an intrinsic stub for `Unsafe::setMemory` for x86_64. See >> [this PR](https://github.com/openjdk/jdk/pull/16760) for discussion around >> this change. >> >> Overall, making this an intrinsic improves overall performance of >> `Unsafe::setMemory` by up to 4x for all buffer sizes. >> >> Tested with tier-1 (and full CI). I've added a table of the before and >> after numbers for the JMH I ran (`MemorySegmentZeroUnsafe`). >> >> [setMemoryBM.txt](https://github.com/openjdk/jdk/files/14808974/setMemoryBM.txt) > > Scott Gibbons has updated the pull request incrementally with one additional > commit since the last revision: > > Address review comments; update copyright years General comment/suggestion before I dive into review. Can we do renaming `UnsafeCopyMemory*` -> `UnsafeMemory*` in follow up RFE. This change hides the real change. src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 8336: > 8334: // Initialize table for copy memory (arraycopy) check. > 8335: if (UnsafeMemoryAccess::_table == nullptr) { > 8336: UnsafeMemoryAccess::create_table(18); Needs comment explaining 18 number src/hotspot/share/utilities/copy.hpp line 303: > 301: inline static void shared_disjoint_words_atomic(const HeapWord* from, > 302: HeapWord* to, size_t > count) { > 303: I don't think this justify to change the file. ------------- Changes requested by kvn (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/18555#pullrequestreview-2012077574 PR Review Comment: https://git.openjdk.org/jdk/pull/18555#discussion_r1572750449 PR Review Comment: https://git.openjdk.org/jdk/pull/18555#discussion_r1572746349
