Integrated: 8270848: Redundant unsafe opmask register allocation in some instruction patterns.

[Jatin Bhateja]

On Fri, 16 Jul 2021 15:51:27 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

> - Some string compare/array equality patters in x86_[32/64].ad files accept the temporary opmark register operands, instructions using these registers are guarded by target feature checks.
> - Even if control path leading to these instructions is not chosen, RA will still allocate physical registers to these temporary operands.
> - Pulling out the feature checks upto the instruction level can save redundant allocations which may effect spilling decisions.
> - Also existing platform dependent routine Matcher::has_predicated_vector() check the existence of AVX512VL feature which is not required.

This pull request has now been integrated.

Changeset: 71ca0c08
Author:    Jatin Bhateja <jbhateja at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/71ca0c08f09e87673f1cf3f918a0802961359166
Stats:     45 lines in 3 files changed: 0 ins; 4 del; 41 mod

8270848: Redundant unsafe opmask register allocation in some instruction patterns.

Reviewed-by: sviswanathan, kvn

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PR: https://git.openjdk.java.net/jdk/pull/4813