JDK-8024070 : C2 needs some form of type speculation
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: hs25
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2013-08-30
  • Updated: 2024-04-05
  • Resolved: 2013-10-23
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JDK 8 Other
8Fixed hs25Fixed
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Description
We drop some profiling data because it's of no immediate use. Rather than dropping it, we should register it with the type system and let it flow in the graph. At points where the static type or the local profiling doesn't help, we could then query the type system for speculative type data and if there's some emit a guard so it becomes the current type.
Comments
Regarding the lack of test case: This change affects the quality of generated code and not correctness. It's hard to observe with a test case because it's hard for a test case to verify generated code.
11-02-2014

URL: http://hg.openjdk.java.net/hsx/hsx25/hotspot/rev/b2ee5dc63353 User: amurillo Date: 2013-10-25 23:52:44 +0000
25-10-2013

URL: http://hg.openjdk.java.net/hsx/hotspot-comp/hotspot/rev/b2ee5dc63353 User: roland Date: 2013-10-23 15:39:43 +0000
23-10-2013