NAME
        IEEESPFloor -- compute Floor function of IEEE single precision number

   SYNOPSIS
          x   = IEEESPFloor(  y  );
          d0                  d0

        float   x,y;

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

   INPUTS
        y -- IEEE single precision floating point value

   RESULT
        x -- IEEE single precision floating point value

   BUGS

   SEE ALSO
        ieeespceil()