[HARMONY-1969] [drlvm][jit] nested synchronized blocks make Jitrino.OPT crash meeting multiple loop entrances to a single loop

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: DRLVM
• Environment: any
• Patch Info: Patch Available
• Assignee: Alexey Varlamov
• Reporter: Egor Pasko
• Created: 26/Oct/06 07:02
• Updated: 02/May/13 02:29
• Resolved: 14/Nov/06 04:41

Description

this is a sub-bug for HARMONY-1908. The reason is $subj. I suggest to restore a normal loop structure in this case (i. e. generalize the eliminateUnnestedLoopsOnDispatch() a little)

of course, loop nesting may be broken in specially crafted bytecode samples (and we will not repair them with the proposed solution), but a reasonable behavoiur in this case would be to move bytecodes like this to JET. Here I am not for moving to JET because of the common nature of the code pattern (nested synches, javac) that we need to run heavily optimized.

To reproduce, disable profiling-related asserts in ControlFlowGraph.cpp, rebuild Jitrino in debug mode.

run DoubleSync (attached) with -Xem:opt

java: /export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/shared/ControlFlowGraph.cpp:384: bool Jitrino::ControlFlowGraph::isEdgeProfileConsistent(bool, bool, bool): Assertion `doAssert?false:true' failed.
SIGABRT in VM code.
Stack trace:
1: ?? (??:-1)
2: abort (??:-1)
3: __assert_fail (??:-1)
4: Jitrino::ControlFlowGraph::isEdgeProfileConsistent(bool, bool, bool) (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/shared/ControlFlowGraph.cpp:385)
5: Jitrino::ControlFlowGraph::smoothEdgeProfile() (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/shared/ControlFlowGraph.cpp:947)
6: Jitrino::StaticProfiler::estimateGraph(Jitrino::IRManager&, double, bool) (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/dynopt/StaticProfiler.cpp:253)
7: Jitrino::StaticProfilerPass::_run(Jitrino::IRManager&) (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/dynopt/StaticProfiler.cpp:293)
8: Jitrino::OptPass::run() (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/optimizer/optpass.cpp:61)
9: Jitrino::runPipeline(Jitrino::CompilationContext*) (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/main/Jitrino.cpp:226)
10: Jitrino::compileMethod(Jitrino::CompilationContext*) (/export/users/evpasko/svn/3/trunk/working_vm/vm/jitrino/src/main/Jitrino.cpp:261)
<snip>

dumping dot files helps significantly

Issue Links

• is depended upon by: HARMONY-1908 [drlvm][opt] failed assert in ControlFlowGraph