https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92164
--- Comment #3 from Steffen Schmidt <steffen-schmidt at siemens dot com> --- Thanks for the quick reply. Just tested using -frounding-math and it seems to fix the issue. Sorry, I was not aware of this option, according to GCCs manual it is experimental. Please correct me if I'm wrong, but my expectation would be, assuming a correct program, switching from -O0 to -O1 should not influence the runtime result.