NAME
        IEEESPAcos -- compute the arc cosine of a number

   SYNOPSIS
          x   = IEEESPAcos(  y  );
        d0                 d0

        float   x,y;

   FUNCTION
        Compute arc cosine of y in IEEE single precision

   INPUTS
        y - IEEE single precision floating point value

   RESULT
        x - IEEE single precision floating point value

   BUGS

   SEE ALSO
        ieeespcos(), ieeespatan(), ieeespasin()