https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94802
--- Comment #11 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:5de7bf5bc98ec9edc6838a443521204d0eca7605 commit r11-6482-g5de7bf5bc98ec9edc6838a443521204d0eca7605 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Jan 5 19:13:29 2021 +0100 expand: Fold x - y < 0 to x < y during expansion [PR94802] My earlier patch to simplify x - y < 0 etc. for signed subtraction with undefined overflow into x < y in match.pd regressed some tests, even when it was guarded to be post-IPA, the following patch thus attempts to optimize that during expansion instead (which is the last time we can do it, afterwards we lose the information whether it was x - y < 0 or (int) ((unsigned) x - y) < 0 for which we couldn't optimize it. 2021-01-05 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/94802 * expr.h (maybe_optimize_sub_cmp_0): Declare. * expr.c: Include tree-pretty-print.h and flags.h. (maybe_optimize_sub_cmp_0): New function. (do_store_flag): Use it. * cfgexpand.c (expand_gimple_cond): Likewise. * gcc.target/i386/pr94802.c: New test. * gcc.dg/Wstrict-overflow-25.c: Remove xfail.
