Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8028471

PPC64 (part 215): opto: Extend ImplicitNullCheck optimization.

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: port-stage-ppc-aix
    • Fix Version/s: port-stage-ppc-aix
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      master
    • CPU:
      ppc
    • OS:
      aix

      Backports

        Description

        ImplicitNullChecks did not work on platforms where the zero
        page is only write protected.
        This change adds os property 'zero_page_read_protected' and extends
        the ImplicitNullCheck optimization to consider only stores if
        this property is not true. If a decoded compressed oop will access the
        guard page before the heap, Loads work again.
        This is needed on AIX, where the page at address '0' is only write-protected.

        ----------------------------

        This is preparation for PPC64 integration: http://openjdk.java.net/jeps/175
        This and following ppc64 changes will go into staging repository first and tested there: http://hg.openjdk.java.net/ppc-aix-port/stage/

        http://hg.openjdk.java.net/ppc-aix-port/jdk8/hotspot/file/338e318f1e12/ppc_patches/0215_opto-extend_ImplicitNullCheck_optimizations.patch

          Attachments

            Issue Links

              Activity

                People

                • Assignee:
                  goetz Goetz Lindenmaier
                  Reporter:
                  goetz Goetz Lindenmaier
                • Votes:
                  0 Vote for this issue
                  Watchers:
                  2 Start watching this issue

                  Dates

                  • Created:
                    Updated:
                    Resolved: