https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106904
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:97d599e09b0fd389a7cbac8867e56977ec97900f commit r12-9254-g97d599e09b0fd389a7cbac8867e56977ec97900f Author: Richard Biener <rguent...@suse.de> Date: Wed Dec 7 14:42:24 2022 +0100 tree-optimization/106904 - bogus -Wstringopt-overflow with vectors The following avoids CSE of &ps->wp to &ps->wp.hwnd confusing -Wstringopt-overflow by making sure to produce addresses to the biggest container from vectorization. For this I introduce strip_zero_offset_components which turns &ps->wp.hwnd into &(*ps) and use that to base the vector data references on. That will also work for addresses with variable components, alternatively emitting pointer arithmetic via calling get_inner_reference and gimplifying that would be possible but likely more intrusive. This is by no means a complete fix for all of those issues (avoiding ADDR_EXPRs in favor of pointer arithmetic might be). Other passes will have similar issues. In theory that might now cause false negatives. PR tree-optimization/106904 * tree.h (strip_zero_offset_components): Declare. * tree.cc (strip_zero_offset_components): Define. * tree-vect-data-refs.cc (vect_create_addr_base_for_vector_ref): Strip zero offset components before building the address. * gcc.dg/Wstringop-overflow-pr106904.c: New testcase. (cherry picked from commit f8d136e50e6f82cba793483d910a2b2643108508)
