PING^3: RFD: C2 bug: 8157306 random infrequent null pointer exceptions in javac

[Vladimir Kozlov]

I tested the fix and hit tests failures:

#  Internal Error (/opt/jprt/T/P1/013538.vkozlov/s/hotspot/src/share/vm/opto/gcm.cpp:417), pid=25539, tid=25645
#  assert(early->dominates(LCA)) failed: early is high enough

V  [libjvm.so+0xa67d0d]  report_vm_error(char const*, int, char const*, char const*, ...)+0xdd
V  [libjvm.so+0xcca62b]  PhaseCFG::insert_anti_dependences(Block*, Node*, bool)+0x157b
V  [libjvm.so+0x69f909]  PhaseCFG::verify() const+0x659
V  [libjvm.so+0x9da558]  Compile::Code_Gen()+0x358

I did not have time to analyze it yet.

Vladimir

On 8/17/16 9:56 AM, Andrew Haley wrote:
> On 05/08/16 04:28, Vladimir Kozlov wrote:
>> On 8/4/16 4:30 PM, Andrew Haley wrote:
>>> On 04/08/16 04:35, Vladimir Kozlov wrote:
>>>
>>>> I can't reproduce the problem any more with latest hs-comp
>>>> sources. Andrew, can you verify this fix?
>>>
>>> Yes, you're right.
>>>
>>> Wouldn't it make sense to surround that code with
>>> ! needs_anti_dependence_check() ?
>>
>> Yes, we should do it.
>
> What do you want to do about this?  It needs to go into jprt.
>
> Which means you, really.
>
> Andrew.
>
>