https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94873
--- Comment #24 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:0f717ba5975ab42e1176db4cd2384f1862872519 commit r9-8895-g0f717ba5975ab42e1176db4cd2384f1862872519 Author: Jakub Jelinek <ja...@redhat.com> Date: Wed May 6 09:31:19 2020 +0200 combine: Don't replace SET_SRC with REG_EQUAL note content if SET_SRC has side-effects [PR94873] There were some discussions about whether REG_EQUAL notes are valid on insns with a single set which contains auto-inc-dec side-effects in the SET_SRC and the majority thinks that it should be valid. So, this patch fixes the combiner to punt in that case, because otherwise the auto-inc-dec side-effects from the SET_SRC are lost. 2020-05-06 Jakub Jelinek <ja...@redhat.com> PR rtl-optimization/94873 * combine.c (combine_instructions): Don't optimize using REG_EQUAL note if SET_SRC (set) has side-effects. * gcc.dg/pr94873.c: New test. (cherry picked from commit 8982e39b46b1e4a4b09022ddebd758b77ab73bac)
