https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114515
--- Comment #4 from Richard Sandiford <rsandifo at gcc dot gnu.org> --- (In reply to Richard Biener from comment #1) > Btw, why does forwprop not do this? Not 100% sure (I wasn't involved in choosing the current heuristics). But fwprop can propagate across blocks, so there is probably more risk of increasing register pressure.
