Is floating point multiplication by zero guaranteed to produce zero?

Question

I understand floating point has rounding errors, but I\'m wondering if there are certain situations where the error does not apply, such as multiplication by zero .

Answer 1

False:

0f * NAN == NAN
0f * INFINITY == NAN

and ...

0f * -1f == -0f (negative 0f), with 0f == -0f :-)

(on Intel, VC++, and probably on any platform that uses IEEE 754-1985 floating points)

Example on ideone (that uses GCC on some Intel compatible platform probably)