https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94261
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to rsand...@gcc.gnu.org from comment #5) > (In reply to Richard Biener from comment #3) > > (In reply to Richard Biener from comment #2) > > > when placing gcc_unreachable () at the swapping place and most testcases > > > still pass when removing the IL operand swapping, only vect-cselim-1.c > > > runfails (investigating). > > > > Ah, SLP ultimately fails here so the scalar IL is broken by the operation > > code adjustment. In the end we should be able to avoid doing tree code > > adjustments as well since we're swapping to make the code the same > > as the first stmts code and we only ever look at the first scalar stmt > > during SLP code-gen/analysis. > > Yeah, started wondering about that later too... So there's probably a single path where this is not true which is when we go through vect_attempt_slp_rearrange_stmts thus when we have a SLPed set of cond-reductions. I'm trying to come up with a testcase ... But I think the cure here should be to punt on vect_slp_rearrange_stmts, do you agree?
