On Fri, 12 Apr 2024 00:07:56 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: > > Addressing yet more review comments src/hotspot/cpu/x86/stubGenerator_x86_64_arraycopy.cpp line 2504: > 2502: Label L_exit, L_fillQuadwords, L_fillDwords, L_fillBytes; > 2503: > 2504: setup_arg_regs(3); A comment stating the placement of dest, size, and byteVal after call to setup_arg_regs() would be very helpful. src/hotspot/cpu/x86/stubGenerator_x86_64_arraycopy.cpp line 2521: > 2519: const Register byteVal = rdx; > 2520: > 2521: // Propagate byte to full Register The comment refers to lines 2524-2526, please move it down. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/18555#discussion_r1561873770 PR Review Comment: https://git.openjdk.org/jdk/pull/18555#discussion_r1561871872
