https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54346
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:fa553ff26d96f6fecaa8f1b00649cfdc6cda5f5a commit r13-3430-gfa553ff26d96f6fecaa8f1b00649cfdc6cda5f5a Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Oct 21 09:16:44 2022 +0200 match.pd: Fix up gcc.dg/pr54346.c on i686-linux [PR54346] The pr54346.c testcase FAILs on i686-linux (without -msse*) for multiple reasons. One is the trivial missing -Wno-psabi which the following patch adds, but that isn't enough. The thing is that without native vector support, we have VEC_PERM_EXPRs in the IL and are actually considering the nested VEC_PERM_EXPRs into one VEC_PERM_EXPR optimization, but punt because can_vec_perm_const_p (result_mode, op_mode, sel2, false) is false. Such a test makes sense to prevent "optimizing" two VEC_PERM_EXPRs that can be handled by the backend natively into one VEC_PERM_EXPR that can't be handled. But if both of the original VEC_PERM_EXPRs can't be handled natively either, having just one VEC_PERM_EXPR that will be lowered by generic vec lowering is IMHO still better than 2. Or even if we trade just one VEC_PERM_EXPR that can't be handled plus one that can to one that can't be handled. Also, removing the testcase's executable permissions... 2022-10-21 <ja...@redhat.com> PR tree-optimization/54346 * match.pd ((vec_perm (vec_perm@0 @1 @2 VECTOR_CST) @0 VECTOR_CST)): Optimize nested VEC_PERM_EXPRs even if target can't handle the new one provided we don't increase number of VEC_PERM_EXPRs the target can't handle. * gcc.dg/pr54346.c: Add -Wno-psabi to dg-options.