JDK-8210260 : [lworld] Improve acmp implementation
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: repo-valhalla
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2018-08-31
  • Updated: 2018-09-12
  • Resolved: 2018-09-10
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Other
repo-valhallaFixed
Related Reports
Relates :  
JDK-8210258 - [lworld] CDS broken
Relates :  
JDK-8210646 - [lworld] C2 compilation fails with "assert(!target->is_ready()) failed: our arrival must be expected"
Description
The implementation of acmp should use the always locked mark word to determine if one of the operands is a value type. We should also improve the implementation according to Sergey's suggestions:
http://mail.openjdk.java.net/pipermail/valhalla-dev/2018-August/004888.html
Comments
http://hg.openjdk.java.net/valhalla/valhalla/rev/1faa4137c6fc
10-09-2018
You can find perf results here: http://cr.openjdk.java.net/~skuksenko/valhalla/acmp1/acmp_charts_0831.png
01-09-2018
http://cr.openjdk.java.net/~thartmann/valhalla/lworld/acmp_optimization/webrev.01/
31-08-2018