NAME
        SPFloor -- compute Floor function of a number.

   SYNOPSIS
        x = SPFloor(y)
        D0          D0

        float SPFloor(float y);

   FUNCTION
        Calculate the largest integer less than or equal to x and return it.

   INPUTS
        y       - Motorola Fast Floating Point number.

   RESULT
        x       - Motorola Fast Floating Point number.

   BUGS
        None.

   SEE ALSO
        spceil()