https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126998
--- Comment #13 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <[email protected]>: https://gcc.gnu.org/g:d8f1bd8c34a289de0810178d897cb246ce2033cf commit r17-3793-gd8f1bd8c34a289de0810178d897cb246ce2033cf Author: Richard Biener <[email protected]> Date: Mon Aug 31 14:19:14 2026 +0200 tree-optimization/126998 - wrong-code with lane-reducing reduction The following fixes wrong excess number of lanes computation in vect_create_constant_vectors, integrating that into vect_get_num_copies_for_invariant because the poly computation has to be constant. PR tree-optimization/126998 * tree-vectorizer.h (vect_get_num_copies_for_invariant): Adjust API. * tree-vect-slp.cc (vect_get_num_copies_for_invariant): Also compute and output the constant number of excess lanes produced. (vect_create_constant_vectors): Adjust. (vect_slp_analyze_node_operations): Likewise. * tree-vect-loop.cc (vectorizable_lane_reducing): Likewise. * gcc.dg/vect/vect-reduc-dot-pr126998-2.c: New testcase.
