[jdk11u-dev] RFR: 8292713: Unsafe.allocateInstance should be intrinsified without UseUnalignedAccesses

[Paul Hohensee]

On Fri, 8 Sep 2023 07:38:09 GMT, Fei Yang <fyang at openjdk.org> wrote:

> Backport to improve arm32 performance in 11u and riscv-port in: https://github.com/openjdk/riscv-port-jdk11u/pull/3.
> This is not a clean backport as the function has been moved to new file and renamed. 
> 
> I checked the 11u related code and I think the following analysis on the JBS description is still true for 11u:
> "The intrinsic is currently only implemented in C2. I see no reason for this intrinsic to depend on `UseUnalignedAccesses`: what `LibraryCallKit::inline_unsafe_allocate()` does seems similar to what the regular `Parse::do_new()` does, namely doing the clinit barrier and then delegating into `GraphKit::new_instance`."
> 
> Tested with the initial riscv-port in: https://github.com/openjdk/riscv-port-jdk11u/pull/3

Clean backport from 17u.

GHA failure is an infrastructure issue.

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Marked as reviewed by phh (Reviewer).

PR Review: https://git.openjdk.org/jdk11u-dev/pull/2125#pullrequestreview-1617574703
PR Comment: https://git.openjdk.org/jdk11u-dev/pull/2125#issuecomment-1711733894