JDK-6710487 : More than half of JDI Regression tests hang with COOPs in -Xcomp mode
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: hs13
  • Priority: P2
  • Status: Closed
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2008-06-04
  • Updated: 2012-02-01
  • Resolved: 2011-03-08
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JDK 6 JDK 7 Other
6u14Fixed 7Fixed hs14Fixed
Related Reports
Relates :  
JDK-6689060 - Escape Analysis does not work with Compressed Oops
Description
More than half of JDI Regression tests hang with COOPs in -Xcomp mode
and as result they fail with timeout.

See comments for more details.
Comments
SUGGESTED FIX Remove DecodeNNode::decode() and EncodePNode::encode() methods. Both nodes now have Identity() and Value() methods which do transformations we need. Replace TypeOopPtr::make_narrowoop() with Type::make_narrowoop() and TypeNarrowOop::make_oopptr() with Type::make_ptr() to simplify the code.
24-06-2008
EVALUATION This change to LoadNode::make: - return new (C, 2) DecodeNNode(load, rt); + return DecodeNNode::decode(&gvn, load); causes the problem. The result of LoadNode::make is passed to _gvn.transform by GraphKit::make_load. decode returns a preexisting Phi that gets simplified too early when passed to transform so that instead of getParent walking up the chain it calls getParent on the same object over and over again.
10-06-2008