Request for reviews (S): 6910605: C2:NullPointerException/ClassCaseException is thrown when C2 with DeoptimizeALot is used

Vladimir Kozlov Vladimir.Kozlov at Sun.COM
Mon Feb 8 11:51:44 PST 2010

Thank you, Tom


Tom Rodriguez wrote:
> I think that looks good.  Thanks for removing reexecute output.
> tom
> On Feb 6, 2010, at 2:43 PM, Vladimir Kozlov wrote:
>> The first implementation was not correct for the case when
>> runtime call is used for multianewarray allocation.
>> Because of that interpreter should not have _multianewarray
>> marked as reexecutable (stack is not reset for such case).
>> Also setting reexecute bit in do_multianewarray() was not
>> propagated to the AllocateArray node so I have to set it in graphKit.
>> I replaced "expand_count == 1" check with "ndimensions == 1"
>> otherwise with MultiArrayExpandLimit=0 we hit ShouldNotReachHere()
>> in case of one dimension multianewarray because the method
>> expand_multianewarray() will not be called.
>> And I removed annoying "reexecute=false" from PcDesc output.
>> Thanks,
>> Vladimir
>> Vladimir Kozlov wrote:
>>> Fixed 6910605: C2: NullPointerException/ClassCaseException is thrown when C2 with DeoptimizeALot is used
>>> Problem:
>>> Regression after 6603492: multianewarray should generate same code as anewarray for 1-d arrays.
>>> After deoptimization interpreter will continue execution after _multianewarray
>>> even if compiled code did not allocate all needed arrays.
>>> Solution:
>>> Set the reexecute bit for the interpreter to reexecute the _multianewarray bytecode
>>> if deoptimization happens. Do it unconditionally even for one dimension array.
>>> Added regression test copied from nsk/coverage/runtime/runtime007
>>> Reviewed by:
>>> Fix verified (y/n): y, tests
>>> Other testing:
>>> JPRT

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