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  1. JDK
  2. JDK-8270848

Redundant unsafe opmask register allocation in some instruction patterns.

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    • b09
    • x86

        - 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.
        - Existing platform dependent routine Matcher::has_predicated_vector() check the existence of AVX512VL feature which is not required.

              jbhateja Jatin Bhateja
              jbhateja Jatin Bhateja
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