> 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 with a new target base due to a
merge or a rebase. The pull request now contains 30 commits:
- Merge branch 'openjdk:master' into setMemory
- Set memory test (#23)
* Even more review comments
* Re-write of atomic copy loops
* Change name of UnsafeCopyMemory{,Mark} to UnsafeMemory{Access,Mark}
* Only add a memory mark for byte unaligned fill
* Remove MUSL_LIBC ifdef
* Remove MUSL_LIBC ifdef
- Set memory test (#22)
* Even more review comments
* Re-write of atomic copy loops
* Change name of UnsafeCopyMemory{,Mark} to UnsafeMemory{Access,Mark}
* Only add a memory mark for byte unaligned fill
- Set memory test (#21)
* Even more review comments
* Re-write of atomic copy loops
* Change name of UnsafeCopyMemory{,Mark} to UnsafeMemory{Access,Mark}
* Only add a memory mark for byte unaligned fill
- Only add a memory mark for byte unaligned fill
* Even more review comments
* Re-write of atomic copy loops
* Change name of UnsafeCopyMemory{,Mark} to UnsafeMemory{Access,Mark}
* Only add a memory mark for byte unaligned fill
- Rename UnsafeCopyMemory{,Mark} to UnsafeMemory{Access,Mark} (#19)
* Even more review comments
* Re-write of atomic copy loops
* Change name of UnsafeCopyMemory{,Mark} to UnsafeMemory{Access,Mark}
- Change fill routines
* Even more review comments
* Re-write of atomic copy loops
- Even more review comments
- Addressing yet more review comments
- Addressing more review comments
- ... and 20 more: https://git.openjdk.org/jdk/compare/140f5671...116d7dd6
-------------
Changes: https://git.openjdk.org/jdk/pull/18555/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18555&range=18
Stats: 635 lines in 37 files changed: 418 ins; 6 del; 211 mod
Patch: https://git.openjdk.org/jdk/pull/18555.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/18555/head:pull/18555
PR: https://git.openjdk.org/jdk/pull/18555
