float IEEESPFloor(
float y );
Calculate the largest integer ieeesp-number
less than or equal to fnum
IEEE single precision floating point
Flags:
zero : result is zero
negative : result is negative
overflow : 0 (???)
IEEESPFloor(10.5) = 10
IEEESPFloor(0.5) = 0
IEEESPFloor(-0.5) = -1
IEEESPFloor(-10.5)= -11