RFR: 8285835: SIGSEGV in PhaseIdealLoop::build_loop_late_post_work

Thu Oct 27 23:20:34 UTC 2022

EA does not adjust NSR (not_scalar_replaceable) state for referenced allocations. 
In the test case object A is NSR because it merges with NULL object. But this state is not propagated to allocations it references. As result other allocations are marked scalar replaceable and related Load node is moved above guarding condition (where A object is checked for NULL).
EA should propagate NSR state.

Thanks to @rwestrel who provided reproducer test case.

Testing tier1-4, xcomp, stress.

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Commit messages:
 - 8285835: SIGSEGV in PhaseIdealLoop::build_loop_late_post_work

Changes: https://git.openjdk.org/jdk/pull/10894/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10894&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8285835
  Stats: 145 lines in 3 files changed: 135 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/10894.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10894/head:pull/10894

PR: https://git.openjdk.org/jdk/pull/10894