https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111228
--- Comment #4 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:caa7a99a052929d5970677c5b639e1fa5166e334 commit r14-3571-gcaa7a99a052929d5970677c5b639e1fa5166e334 Author: Richard Biener <rguent...@suse.de> Date: Wed Aug 30 11:57:47 2023 +0200 tree-optimization/111228 - combine two VEC_PERM_EXPRs The following adds simplification of two VEC_PERM_EXPRs where the later one replaces all elements from either the first or the second input of the earlier permute. This allows a three input permute to be simplified to a two input one. I'm following the existing two input simplification case and only allow non-VLA permutes. The now existing three cases and the single case in tree-ssa-forwprop.cc somehow ask for merging, I'm not doing this as part of this change though. PR tree-optimization/111228 * match.pd ((vec_perm (vec_perm ..) @5 ..) -> (vec_perm @x @5 ..)): New simplifications. * gcc.dg/tree-ssa/forwprop-42.c: New testcase.
