https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92164
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Steffen Schmidt from comment #3) > 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. GCC assumes you do not mess with the floating-point state but round-to-nearest is in effect. You have to use -frounding-math to remove this assumption but then still correct operation isn't guaranteed (thus the "experimental" tag for this option).
