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  1. JDK
  2. JDK-8269828

corrections in some instruction patterns for KNL x86 platform

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    • Subcomponent:
    • Resolved In Build:
      b31
    • CPU:
      x86
    • Verification:
      Verified

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        Currently a temporary operand with register class regD is used in rep_stos_evex and rep_stos_large_evex instruction patterns, whose encoding blocks calls xmm_clear_mem routine which has a VEX encoded instruction in the control path.
        Thus regD class should be changed to legRegD on AVX512 platforms so that operand is always allocated from lower register bank (0-15).

        There is one more issue related to usage of regD operand which is a scalar operand in a vector instruction, usually such cases may result into problems during spilling/restoration since only a scalar value is dumped and restored back, but in current context its a temporary operand may never get spilled.

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                Assignee:
                jbhateja Jatin Bhateja
                Reporter:
                kvn Vladimir Kozlov
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