https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111015
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:beabb96786e4b3e1a820e400c09b1c1c9ab06287 commit r11-10968-gbeabb96786e4b3e1a820e400c09b1c1c9ab06287 Author: Jakub Jelinek <ja...@redhat.com> Date: Wed Aug 30 10:47:21 2023 +0200 store-merging: Fix up >= 64 bit insertion [PR111015] The following testcase shows that we mishandle bit insertion for info->bitsize >= 64. The problem is in using unsigned HOST_WIDE_INT shift + subtraction + build_int_cst to compute mask, the shift invokes UB at compile time for info->bitsize 64 and larger and e.g. on the testcase with info->bitsize happens to compute mask of 0x3f rather than 0x3f'ffffffff'ffffffff. The patch fixes that by using wide_int wi::mask + wide_int_to_tree, so it handles masks in any precision (up to WIDE_INT_MAX_PRECISION ;) ). 2023-08-30 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/111015 * gimple-ssa-store-merging.c (imm_store_chain_info::output_merged_store): Use wi::mask and wide_int_to_tree instead of unsigned HOST_WIDE_INT shift and build_int_cst to build BIT_AND_EXPR mask. * gcc.dg/pr111015.c: New test. (cherry picked from commit 49a3b35c4068091900b657cd36e5cffd41ef0c47)