(C) 1996 AROS - The Amiga Replacement OS
Flags: zero : result is zero negative : result is negative overflow : 0 (???)
floor(10.5) = 10 floor(0.5) = 0 floor(-0.5) = -1 floor(-10.5)= -11
Generate a mask of exponent(y) (where y is the given ffp-number) bits starting with bit 31. If y < 0 then test whether it is already an integer. If not then y = y - 1 and generate that mask again. Use the mask on the mantisse.