search for: r187314

In r187314, APFloat multiplication by with NaNs was made to always yield a positive NaN. I am wondering whether that was the correct decision. It is of course true that the result of a multiplication is undefined in IEEE, however, we were using multiplication by -1.0 to implement IEEE negate, which is defined...

...e) > > Multiplying by -1.0 has the potential to raise a floating point exception on sNaN inputs, and hence is not a valid implementation of negation per IEEE 754. > > —Owen > > On Aug 6, 2014, at 9:51 PM, Keno Fischer <kfischer at college.harvard.edu> wrote: > >> In r187314, APFloat multiplication by with NaNs was made to always >> yield a positive NaN. I am wondering whether that was the correct >> decision. It is of course true that the result of a multiplication is >> undefined in IEEE, however, we were using multiplication by -1.0 to >> imp...

...al to raise a floating point exception on sNaN inputs, and hence is not a valid implementation of negation per IEEE 754. >>> >>> —Owen >>> >>> On Aug 6, 2014, at 9:51 PM, Keno Fischer <kfischer at college.harvard.edu> wrote: >>> >>>> In r187314, APFloat multiplication by with NaNs was made to always >>>> yield a positive NaN. I am wondering whether that was the correct >>>> decision. It is of course true that the result of a multiplication is >>>> undefined in IEEE, however, we were using multiplication...