https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115843
--- Comment #21 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:b35276655e6767a6e037e58edfa4738317498337 commit r13-8936-gb35276655e6767a6e037e58edfa4738317498337 Author: Richard Biener <rguent...@suse.de> Date: Mon Jul 15 13:01:24 2024 +0200 Fixup unaligned load/store cost for znver4 Currently unaligned YMM and ZMM load and store costs are cheaper than aligned which causes the vectorizer to purposely mis-align accesses by adding an alignment prologue. It looks like the unaligned costs were simply left untouched from znver3 where they equate the aligned costs when tweaking aligned costs for znver4. The following makes the unaligned costs equal to the aligned costs. This avoids the miscompile seen in PR115843 but it's of course not a real fix for the issue uncovered there. But it makes it qualify as a regression fix. PR tree-optimization/115843 * config/i386/x86-tune-costs.h (znver4_cost): Update unaligned load and store cost from the aligned costs. (cherry picked from commit 1e3aa9c9278db69d4bdb661a750a7268789188d6)