https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85804
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |WAITING --- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> --- It looks like we now classify as VMAT_ELEMENTWISE (but we don't actually dump the choice) and fail to vectorize because of cost issues and the vectorization with -fno-vect-cost-model is different enough. So fixed on trunk? Can somebody bisect what fixed it? I suppose it was commit 04b99da898a9817e72fedb4063589648b7961ac5 Author: Richard Biener <rguent...@suse.de> Date: Thu Oct 1 15:12:35 2020 +0200 tree-optimization/97236 - fix bad use of VMAT_CONTIGUOUS This avoids using VMAT_CONTIGUOUS with single-element interleaving when using V1mode vectors. Instead keep VMAT_ELEMENTWISE but continue to avoid load-lanes and gathers. 2020-10-01 Richard Biener <rguent...@suse.de> PR tree-optimization/97236 * tree-vect-stmts.c (get_group_load_store_type): Keep VMAT_ELEMENTWISE for single-element vectors. * gcc.dg/vect/pr97236.c: New testcase. which sounds like a duplicate?