https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113833
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- I suspect the issue would pop up with -Ofast -fno-vect-cost-model for any sub-architecture. The patch referenced just adjusts costs for doing BB vectorization (and there's reductions there as well). It might be interesting to offer more high-level knobs to tune for vectorization, say -fno-vect-bb-reduction or -fforce-in-order-bb-reduction-vectorization. A compare before/after the patch of -fopt-info-vec output might show the few cases that are affected by the patch.
