https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120440
--- Comment #17 from Sam James <sjames at gcc dot gnu.org> --- Created attachment 62017 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62017&action=edit build-gnat.sh With the attached script, I can toggle the breakage by changing the cmdline for a-except.o. It assumes: * tree at /home/sjames/build/gcc-bad (built w/ -O2 -march=x86-64-v3) * tree at /home/sjames/build/gcc-maybe (which it modifies) * tree at /home/sjames/build/gcc-good (built w/ -O2 -march=x86-64-v2) I don't think I can proceed further though.