https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77515
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- >This seems to be in violation of preservation of exactly the same results Huh? Where did you read that? Also GCC defaults not to on but to: -ffp-contract=fast Read: https://gcc.gnu.org/onlinedocs/gcc-6.2.0/gcc/Optimize-Options.html#index-ffp-contract-715 Where it says that :).
