https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104479
--- Comment #3 from rguenther at suse dot de <rguenther at suse dot de> --- On Thu, 10 Feb 2022, crazylht at gmail dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104479 > > --- Comment #2 from Hongtao.liu <crazylht at gmail dot com> --- > (In reply to Richard Biener from comment #1) > > Confirmed. When uncond_op is expensive (there's *div amongst them) that's > > definitely unwanted. OTOH when it is cheap then combining will reduce > > latency. > > > > GIMPLE wise it's a neutral transform if uncond_op is not single-use unless > > we need two v_c_es. > > We can leave it to rtl combine/fwprop which will consider rtx_cost for them. That certainly makes sense for the !single_use case.
