[jdk11u-dev] RFR: 8270947: AArch64: C1: use zero_words to initialize all objects

[Paul Hohensee]

On Fri, 4 Nov 2022 17:59:57 GMT, Xin Liu <xliu at openjdk.org> wrote:

> We would like to backport [JDK-8270947](https://bugs.openjdk.org/browse/JDK-8270947) to jdk11u. It's not only less code to maintain, but also better generated code. C1 can leverage DC ZVA in large allocations on aarch64. The secondary consideration is that openjdk11u aligns with oraclejdk11u. 
> 
> This isn't a clean backport. Small cosmetic changes are made in `MacroAssembler::zero_words(Register ptr, Register cnt)` chunk. 
> 
> There are also 2 trailing bugfixes. We will post them together as stacked PRs

Passed tier1. Lgtm.

Pre-submit failure looks to be an infrastructure issue.

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Marked as reviewed by phh (Reviewer).

PR: https://git.openjdk.org/jdk11u-dev/pull/1502