> 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 with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 14 additional commits since the last revision: - Rollback lazy Segment adapter cache per vernee, fix header indent - Merge branch 'master' of https://github.com/openjdk/jdk into feature/ffm-vh-inline - Jorn vernee review - Review remarks, dates, some more simplifications - More cleanup - Merge branch 'master' of https://github.com/openjdk/jdk into feature/ffm-vh-inline - Make sure the form impl class is initialized - Reduce MT initialization work - MH linkToStatic stall - Merge branch 'master' of https://github.com/openjdk/jdk into feature/ffm-vh-inline - ... and 4 more: https://git.openjdk.org/jdk/compare/23dee8fd...d59ff23a ------------- Changes: - all: https://git.openjdk.org/jdk/pull/23720/files - new: https://git.openjdk.org/jdk/pull/23720/files/3d558a2d..d59ff23a Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=23720&range=03 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23720&range=02-03 Stats: 13038 lines in 332 files changed: 7301 ins; 4580 del; 1157 mod Patch: https://git.openjdk.org/jdk/pull/23720.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/23720/head:pull/23720 PR: https://git.openjdk.org/jdk/pull/23720
