https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98207
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #2) > The default is to use fused multiple add. > If you don't want to use FMA, then use -ffp-contract=off (the default =fast). > > > x84_64 by default does not have a fused-multiple-add instruction without > extra options (to enable the ISA for fused multiple add instruction). Note this is still IEEE compliant FP and C standard compliant too.
