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

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

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Fixed
    • Icon: P4 P4
    • port-stage-ppc-aix
    • port-stage-ppc-aix
    • hotspot
    • None
    • master
    • ppc
    • aix

        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

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

                Created:
                Updated:
                Resolved: