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  1. JDK
  2. JDK-8255838

Use 32-bit immediate movslq in macro assembler if 64-bit value fits in 32 bits on x86_64

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    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 16
    • Fix Version/s: 16
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b23

      Description

      Currently, Macro::Assembler(Address dst, intprt_t src) on x64 uses an intermediate scratch register to store the 64-bit immediate.

      But, if the value fits into 32-bits, we can also explicitly use the 32-bit immediate overload, which saves an instruction and a register use.

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              Assignee:
              jvernee Jorn Vernee
              Reporter:
              jvernee Jorn Vernee
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