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  1. JDK
  2. JDK-8159063

aarch64: optimise unaligned array copy long

    Details

    • Subcomponent:
    • Resolved In Build:
      b131
    • CPU:
      aarch64
    • OS:
      linux

      Description

      The code generate for copy array of long is not optimised for the case where the src and/or dest are not 128 bit aligned.

      Some partners HW has improved performance when the address is 128 bit aligned.

      This issue proposed optimising array copy long so that all load/store are 128 bit aligned even when the src/dst are not aligned with respect to each other.

      A new flag will be provided -XX:+AvoidUnalignedAccesses to enable this. This flag will be turned on by default for partners where it is known that there is a performance benefit.

        Activity

        Hide
        kvn Vladimir Kozlov added a comment - - edited
        FC Extension Request
        Justification: performance improvement.
        Risk: Low. Only AARCH64 code is changed
        Proposed Integration Date: June 30, 2016
        Show
        kvn Vladimir Kozlov added a comment - - edited FC Extension Request Justification: performance improvement. Risk: Low. Only AARCH64 code is changed Proposed Integration Date: June 30, 2016
        Hide
        kvn Vladimir Kozlov added a comment -
        Approved for JDK 9.
        Show
        kvn Vladimir Kozlov added a comment - Approved for JDK 9.
        Hide
        hgupdate HG Updates added a comment -
        URL: http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/52ff928336eb
        User: enevill
        Date: 2016-06-24 16:33:15 +0000
        Show
        hgupdate HG Updates added a comment - URL: http://hg.openjdk.java.net/jdk9/hs-comp/hotspot/rev/52ff928336eb User: enevill Date: 2016-06-24 16:33:15 +0000
        Hide
        hgupdate HG Updates added a comment -
        URL: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/52ff928336eb
        User: lana
        Date: 2016-08-10 20:19:27 +0000
        Show
        hgupdate HG Updates added a comment - URL: http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/52ff928336eb User: lana Date: 2016-08-10 20:19:27 +0000

          People

          • Assignee:
            enevill Ed Nevill
            Reporter:
            enevill Ed Nevill
          • Votes:
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            Watchers:
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            Dates

            • Created:
              Updated:
              Resolved: