JDK-8173195 : [BACKOUT] 8087341: C2 doesn't optimize redundant memory operations with G1
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 9
  • Priority: P2
  • Status: Closed
  • Resolution: Fixed
  • Submitted: 2017-01-23
  • Updated: 2020-09-01
  • Resolved: 2017-01-25
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JDK 10 JDK 9
10Fixed 9 b156Fixed
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Description
JDK-8087341 causes an anti-dependency on the volatile membar that results in a crash in the register allocator due to invalid instruction scheduling (see JDK-8172850). Since we are very late in the JDK 9 release cycle, we should back out the change and redo the enhancement in JDK 10.
Comments
verified by PIT testing
26-07-2017

[~jwilhelm], this is an integration blocker because it will fix JDK-8172850 which is an integration blocker.
24-01-2017

Tobias, okay.
23-01-2017

What makes this an integration blocker? If it is caused by JDK-8087341 that was pushed in March 2016 the problem is already in jdk9/dev and this is per definition not a blocker.
23-01-2017

I think we could but from my understanding most the aarch64 changes are required as well. Roland will re-do them with JDK-8173196.
23-01-2017

Can we revert only C2 code and not aarch64?
23-01-2017

http://cr.openjdk.java.net/~thartmann/8173195/webrev.00/
23-01-2017