On Fri, 21 Feb 2025 20:14:19 GMT, Chen Liang <li...@openjdk.org> wrote:
>> Simplify the layout access var handles to be direct in some common cases. >> Also made `VarHandle::isAccessModeSupported` report if an access mode is >> supported for a VH. >> >> Reduces the instructions to execute this code in a simple main by 47%: >> >> long[] arr = new long[8]; >> var ms = MemorySegment.ofArray(arr); >> ms.setAtIndex(ValueLayout.JAVA_BYTE, 12, (byte) 3); >> >> >> Main overheads in FFM are identified to be: >> 1. Eager initialization of direct MethodHandle; can be CDS archived >> 2. MH combinator forms via LambdaFormEditor, not cached right now and always >> have large overhead >> >> Still need other measures to deal with common user patterns of >> `MethodHandles.insertCoordinates(vh, 1, 0L)` which currently is still very >> slow. >> >> Tests: 2 unrelated failures on tier 1-3 > > Chen Liang has updated the pull request incrementally with one additional > commit since the last revision: > > Review remarks, dates, some more simplifications Marked as reviewed by mcimadamore (Reviewer). ------------- PR Review: https://git.openjdk.org/jdk/pull/23720#pullrequestreview-2640368169
