Integrated: 8350840: C2: x64 Assembler::vpcmpeqq assert: failed: XMM register should be 0-15

[Jatin Bhateja]

On Tue, 11 Mar 2025 10:46:39 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

> This bug fix patch addressed an assertion failure due to unexpected register operand encoding.
> AVX2 flavour of instruction "vpcmpeqq" expects to operate over XMM registers from lower register bank (0-15), in this case, the register mask associated with the destination vector operand of the matcher pattern also includes registers from the higher bank.
> 
> The issue can be reliably reproduced if we modify the static allocation order of XMM register through AD file change.
> Existing bug [JDK-8343294](https://bugs.openjdk.org/browse/JDK-8343294) already tracks the requirement to randomize the allocation ordering.
> 
> Kindly review and share your feedback.
> 
> Best Regards,
> Jatin

This pull request has now been integrated.

Changeset: 41cc049f
Author:    Jatin Bhateja <jbhateja at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/41cc049f425e0b7c90ad3870102366a836eb2209
Stats:     3 lines in 2 files changed: 0 ins; 1 del; 2 mod

8350840: C2: x64 Assembler::vpcmpeqq assert: failed: XMM register should be 0-15

Reviewed-by: sviswanathan, kvn

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PR: https://git.openjdk.org/jdk/pull/23979