RFR(XS) 8068909: SIGSEGV in c2 compiled code with OptimizeStringConcat

[Vladimir Kozlov]

Yes, the fix looks reasonable. We had other similar cases which were 
fixed similar way.

Add a comment why we have NULL control there.

And you need to add the attached to bug report test to compiler 
regression tests. We will verify it with 8030976 disabled.

Also it is too late for 8u40 so will backport it to 8u60.

Thanks,
Vladimir

On 1/15/15 12:24 AM, Volker Simonis wrote:
> Hi Vladimir,
>
> please find Axels webrev here:
>
> http://cr.openjdk.java.net/~simonis/webrevs/2015/8068909/
>
> Regards,
> Volker
>
> PS: unfortunately Axel can't access his OpenJDK webrev-space any more
> since it was moved sometimes last summer but we will try once again to
> reactivate it now.
>
> On Wed, Jan 14, 2015 at 7:46 PM, Vladimir Kozlov
> <vladimir.kozlov at oracle.com> wrote:
>> Hi Axel,
>>
>> Thank you for looking on this issue.
>> Before we start reviewing it, please, publish webrev on cr.openjdk.java.net.
>> It is requirement for accepting changes. Your colleagues can help you.
>>
>> Regards,
>> Vladimir
>>
>>
>> On 1/14/15 2:53 AM, Siebenborn, Axel wrote:
>>>
>>> Hi,
>>>
>>> I investigated a crash with jdk8_u25 and opened the following bug:
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-8068909
>>>
>>> I would suggest the following fix:
>>>
>>> http://www.sapjvm.com/as/webrevs/8068909/
>>>
>>> If the control of the inserted load, to NULL. In this case, its
>>> corresponding nullcheck will be found as required edge
>>> to the CastPP during MemNode::Ideal_common_DU_postCCP.
>>>
>>> Thanks,
>>>
>>> Axel
>>>
>>