Extend tree-call-cdce to calls whose result is used

Michael Matz matz@suse.de
Mon Nov 16 16:19:00 GMT 2015


On Mon, 16 Nov 2015, Richard Biener wrote:

> >> Which would leave us with a lowering stage early in the main 
> >> optimization pipeline - I think fold_builtins pass is way too late 
> >> but any "folding" pass will do (like forwprop or backprop where the 
> >> latter might be better because it might end up computing FP "ranges" 
> >> to improve the initial lowering code).
> >
> > This isn't at all related to what backprop is doing though. backprop 
> > is about optimising definitions based on information about all uses.

Right, I think backprop would be even worse than call_cdce, that pass has 
a completely different structure.

> >> Of course call_cdce is as good as long as it still exists.
> >
> > Does this meann that you're not against the patch in principle (i.e. 
> > keeping call_cdce for now and extending it in the way that this patch 
> > does)?
> Yes, I'm fine with extending call_cdce.  Of course I'd happily approve a 
> patch dissolving it into somewhere where it makes more sense.  But this 
> shouldn't block this patch.

Okay, I like merging passes, so I'll try to do that, once the stuff is in 


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