On 5/24/19 6:45 AM, Richard Biener wrote: [ Aggressive snipping ] > As said in my first review I'd just check whether for the > edge we want to thread through the definition comes from a CMP. > Suppose you have > > # val_1 = PHI <a_2, b_3, c_4> > if (val_1 != 0) > > and only one edge has a b_3 = d_5 != 0 condition it's still > worth tail-duplicating the if block. Agreed. The cost of tail duplicating here is so small we should be doing it highly aggressively. About the only case where we might not want to would be if we're optimizing for size rather than speed. That case isn't clearly a win either way.
jeff
