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  1. JDK
  2. JDK-8235551

BitMap::count_one_bits should use population_count

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    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 14
    • Fix Version/s: 14
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc
    • Resolved In Build:
      b27

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        Description

        BitMap::count_one_bits has a handrolled implementation of population_count, generating a 256-element lookup on first use and doing byte-by-byte lookup. This is similar to what RegMask did before introduction of a population_count utility function in JDK-8217519

        BitMap needs the population_count to allow for both 32- and 64-bit unsigned integers, while the current population_count only accepts 32-bit unsigned integers.

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                Assignee:
                redestad Claes Redestad
                Reporter:
                redestad Claes Redestad
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                  Updated:
                  Resolved: