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  1. JDK
  2. JDK-8256046

Shenandoah: Mix-in NULL_PTR in non-strong ShLRBNode's type

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    • Subcomponent:
      gc
    • Resolved In Build:
      b24
    • CPU:
      generic
    • OS:
      generic

      Description

      Testing found this problem (very rare/hard to reproduce):

      # Internal Error (d:/a/jdk/jdk/jdk/src/hotspot/cpu/x86/macroAssembler_x86.cpp:880), pid=6160, tid=5828
      # fatal error: DEBUG MESSAGE: unexpected null in intrinsic

      I believe this may be caused by non-strong LRB reporting a non-NULL type by passing-through its input's type, even though it may actually return NULL on non-NULL inputs. If this serves as input to an intrinsic, it may lead to elimination of surrounding null-check, and thus end up passing a NULL to the intrinsic even thought it should not.

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              Assignee:
              rkennke Roman Kennke
              Reporter:
              rkennke Roman Kennke
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                Created:
                Updated:
                Resolved: