https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102788
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:eb032893675afea4b01cc6ad06a3e0dcfe9b51cd commit r12-4472-geb032893675afea4b01cc6ad06a3e0dcfe9b51cd Author: Richard Biener <rguent...@suse.de> Date: Mon Oct 18 10:31:19 2021 +0200 tree-optimization/102788 - avoid spurious bool pattern fails Bool pattern recog is required for correctness since vectorized compares otherwise produce -1 for true so any context where bool is used as value and not as condition or mask needs to be replaced with CMP ? 1 : 0. When we fail to find a vector type for the result of such use we may not simply elide such transform since a new bool result can emerge when for example the cast_forwprop pattern is applied. So the following avoids failing of the bool pattern recog process and instead not assign a vector type for the stmt. 2021-10-18 Richard Biener <rguent...@suse.de> PR tree-optimization/102788 * tree-vect-patterns.c (vect_init_pattern_stmt): Allow a NULL vectype. (vect_pattern_recog_1): Likewise. (vect_recog_bool_pattern): Continue matching the pattern even if we do not have a vector type for a conversion result. * g++.dg/vect/pr102788.cc: New testcase.