Request for reviews (S): 6877254: Server vm crashes with "no branches off of store slice" when run with CMS and UseSuperWord (default)

Changpeng Fang Changpeng.Fang at Sun.COM
Thu Sep 10 15:13:58 PDT 2009

Updated with the test removed!

* if (mem != my_store) {*



On 09/08/09 21:34, Tom Rodriguez wrote:
> On Sep 8, 2009, at 6:30 PM, Vladimir Kozlov wrote:
>> I have concerns about StoreCMNode::Ideal(aidx) implementation.
>> The result of memory_at() is never the same mergemem node.
>> I either mergemem->base_memory() or mergemem->in(aidx)
>> so your check will be always true.
> You're right but i think that just means we can drop that test.
>> Also mergemem nodes could be chained when the result of memory_at()
>> is also mergemem.
> I figured Ideal would be called again if there was more work to do and 
> it should be a rare case anyway.  The mem of a StoreCM should only be 
> something besides a Store if the StoreCM is dead or if something weird 
> has gone on with cloning.  These changes are pretty conservative since 
> we don't have a clear set of rules for when a StoreCM is dead though I 
> think we could if we wanted to.
> tom
>> You can look on methods in memnode.cpp which search through
>> mergemem for stores: step_through_mergemem(), find_previous_store().
>> Thanks,
>> Vladimir
>> Changpeng Fang wrote:
>>> Need additional reviews (Tom (never) proposed the implementation, so 
>>> I assume he is oked )!
>>> Comments are in the webrev.
>>> On 09/01/09 11:07, Changpeng Fang wrote:
>>>> Thanks,
>>>> Changpeng
>>> Thanks,
>>> Changpeng

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