On October 30, 2017 8:22:52 PM GMT+01:00, Marc Glisse <marc.gli...@inria.fr> wrote: >On Mon, 30 Oct 2017, Jeff Law wrote: > >>> +/* Optimize various special cases of (FTYPE) N CMP (FTYPE) M. */ >>> +(for cmp (lt le eq ne ge gt) >>> + (simplify >>> + (cmp (float@0 @1) (float @2)) >> Since this runs on GENERIC as well as GIMPLE, I don't think you can >rely >> on the types of the float expressions being the same?!? Which >implies >> subsequent code will need and fmt1/fmt2 because you don't know >they're >> necessarily the same. > >Why would GENERIC have comparisons of operands with different types? >The >front-ends first convert both sides to the same type before sending it >anywhere near the folding machinery. I am pretty sure we have a number >of >other places in match.pd where we assume that the existence of the >expression "a OP b" implies that the types of a and b are the same.
In fact GENERIC is more strict and requires equal types for operands. Richard.
