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  1. JDK
  2. JDK-8217519

Improve RegMask population count calculation

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    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 13
    • Fix Version/s: 13
    • Component/s: hotspot
    • Subcomponent:
    • Resolved In Build:
      b05

      Description

      RegMask uses an archaic population count using a byte lookup table.

      While we might not be able to use POPCNT and other instructions directly from native compiled code without going through hoops, an optimized version can be very profitable, e.g., based on the implementation in java.lang.Integer.bitCount.

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              • Assignee:
                redestad Claes Redestad
                Reporter:
                redestad Claes Redestad
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                • Created:
                  Updated:
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