On Tue, 3 Sep 2024 07:52:44 GMT, Per Minborg <pminb...@openjdk.org> wrote:
> This PR proposes to handle smaller FFM copy operations with Java code rather > than transitioning to native code. This will improve performance. In this PR, > copy operations involving zero to 63 bytes will be handled by Java code. > > Here is what it looks like for Windows x64: > >  > > Here is another chart for Linux a64: > >  > > Other platforms exhibit similar behavior. It should be noted that the gain > with this PR is pronounced for certain common sizes that are more likely to > appear in code (e.g. 8, 16, 24, and 32) > > It would be possible to use the same code path for the 7arg > `MemorySegment::copy` method if it is similar to: > > > MemorySegment.copy(heapSrcSegment, JAVA_BYTE, 0, heapDstSegment, JAVA_BYTE, > 0, ELEM_SIZE); > > > This could be added in a separate PR. > > This PR has been tested with tier1-3 and passed. This pull request has now been integrated. Changeset: 6be92726 Author: Per Minborg <pminb...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/6be927260a84b1d7542167e526ff41f7dc26cab0 Stats: 299 lines in 4 files changed: 286 ins; 6 del; 7 mod 8338591: Improve performance of MemorySegment::copy Reviewed-by: mcimadamore ------------- PR: https://git.openjdk.org/jdk/pull/20829
