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  1. JDK
  2. JDK-8137049

Code quality: reducing an trivial integer loop does not produce an optimal code

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 9
    • Fix Version/s: 9
    • Component/s: hotspot
    • Subcomponent:
    • Resolved In Build:
      b107

      Description

      Reported here:
       http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2015-September/019093.html

      Indeed, running that simple benchmark on current JDK 9 and under -prof perfasm yields an ineffective code (see comments in the code):
       http://cr.openjdk.java.net/~shade/8137049/LoopReduceBench.java

      Full perfasm log:
       http://cr.openjdk.java.net/~shade/8137049/loop-reduce.perfasm

      Runnable benchmark:
       http://cr.openjdk.java.net/~shade/8137049/benchmarks.jar (-prof perfasm to produce output)

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            • Assignee:
              roland Roland Westrelin
              Reporter:
              shade Aleksey Shipilev
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              • Created:
                Updated:
                Resolved: