NAME
        IEEESPSub -- subtract one single precision IEEE number from another

   SYNOPSIS
          x   = IEEESPSub(  y  ,  z  );
         d0                d0     d1

        float   x,y,z;

   FUNCTION
        Compute x = y - z in IEEE single precision.

   INPUTS
        y -- IEEE single precision floating point value
        z -- IEEE single precision floating point value

   RESULT
        x -- IEEE single precision floating point value

   BUGS

   SEE ALSO
        ieeespadd()