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Re: Proposal for path splitting for reduction in register pressure for Loops.


On Sun, Mar 8, 2015 at 8:49 PM, Jeff Law <law@redhat.com> wrote:
> On 03/08/15 12:13, Richard Biener wrote:
>>
>>
>> I see.  This basically creates two loop latches and thus will make our
>> loop detection code turn the loop into a fake loop nest.  Not sure if that
>> is a good idea.
>
> I'd have to sit down and ponder this for a while -- what would be the
> register pressure implications of duplicating the contents of the join block
> into its predecessors, leaving an empty joiner so that we still have a
> single latch?

Good question.  Now another question is why we don't choose this
way to disambiguate loops with multiple latches?  (create a forwarder
as new single latch block)

Richard.

> Jeff


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