review (S) for 6984979: OptimizeFill misses some cases with an odd memory graph
vladimir.kozlov at oracle.com
Wed Sep 15 16:42:18 PDT 2010
Tom Rodriguez wrote:
> I don't think it's possible for it to be structured any other way, but I can add that check to the initial sanity check of the store. I've updated the webrev.
> On Sep 15, 2010, at 2:41 PM, Vladimir Kozlov wrote:
>> Should we also check that n->is_Phi() && n->in(LoopNode::LoopBackControl) == store?
>> Tom Rodriguez wrote:
>>> 6984979: OptimizeFill misses some cases with an odd memory graph
>>> The logic for the new OptimizeFill code misses a case where the Phi
>>> usage is different than expected. Sometimes during transformation of
>>> the loop there are uses of the memory phi outside the loop. This
>>> appears to be a valid though slightly surprising structure but it
>>> interferes with the fill matching logic that assumes the store in the
>>> loop should be the only outgoing state. The fix is to allow the phi
>>> to be used outside the loop and replace it with the outgoing memory of
>>> the call to the fill. Tested with jbb, runthere and ctw.
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