https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111267
--- Comment #12 from Richard Sandiford <rsandifo at gcc dot gnu.org> --- I don't object to the patch, but for the record: the current heuristics go back a long way. Although I reworked the pass to use rtl-ssa a few years ago, I tried as far as possible to preserve the old heuristics (tested by making sure that there were no unexplained differences over a large set of targets). I wouldn't characterise the old heuristics as a logic error. Although I didn't write them, my understanding is that they were being deliberately conservative, in particular due to the risk of introducing excess register pressure. So this change seems potentially quite invasive for stage 4. Perhaps it'll work out — if so, great! But if there is some fallout, I think we should lean towards reverting the patch and revisiting in GCC 15.
