(In reply to Michel Dänzer from comment #6)
> (In reply to Matt Arsenault from comment #5)
> > It seems bizarre that an llvm intrinsic would ever be changed to something
> > involving a library call.
> 
> I think the exp2 -> ldexpf transform is rather questionable for us anyway,
> since we have a native exp2 instruction, isn't it? Maybe we just don't want
> to use the LibCallSimplifier pass? The comment at the top of
> SimplifyLibCalls.cpp kind of sounds like "this is not the pass you're
> looking for"...

We do want this. ldexp is a full rate instruction, and exp2 is a quarter rate
instruction.