Integrated: 8339113: AccessFlags can be u2 in metadata

[Coleen Phillimore]

On Tue, 19 Nov 2024 16:18:48 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> Please review this change that makes AccessFlags and modifier_flags u2 types and removes the last remnants of Hotspot adding internal access flags.  This change moves AccessFlags and modifier_flags in Klass to alignment gaps saving 16 bytes.  From pahole: so it's a bit better.
> 
> before:
> 
>         /* size: 216, cachelines: 4, members: 25, static members: 17 */
>         /* sum members: 194, holes: 3, sum holes: 18 */
> 
> 
> after:
> 
>         /* size: 200, cachelines: 4, members: 25, static members: 17 */
>         /* sum members: 188, holes: 4, sum holes: 12 */
> 
> 
> We may eventually move the modifiers to java.lang.Class but that's WIP.
> 
> Tested with tier1-7 on oracle platforms.  Did test builds on other platforms (please try these changes ppc/arm32 and s390).  Also requires minor Graal changes.

This pull request has now been integrated.

Changeset: 098afc8b
Author:    Coleen Phillimore <coleenp at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/098afc8b7d0e7caa82999fb9d4e319ea8aed09a1
Stats:     328 lines in 58 files changed: 45 ins; 50 del; 233 mod

8339113: AccessFlags can be u2 in metadata

Co-authored-by: Amit Kumar <amitkumar at openjdk.org>
Reviewed-by: sspitsyn, vlivanov, yzheng, dlong, dholmes

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PR: https://git.openjdk.org/jdk/pull/22246