static const double 
one =  1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
C1  =  4.16666666666666019037e-02, /* 0x3FA55555, 0x5555554C */
C2  = -1.38888888888741095749e-03, /* 0xBF56C16C, 0x16C15177 */
C3  =  2.48015872894767294178e-05, /* 0x3EFA01A0, 0x19CB1590 */
C4  = -2.75573143513906633035e-07, /* 0xBE927E4F, 0x809C52AD */
C5  =  2.08757232129817482790e-09, /* 0x3E21EE9E, 0xBDB4B1C4 */
C6  = -1.13596475577881948265e-11; /* 0xBDA8FAE9, 0xBE8838D4 */

double
mcos(double x)
{
  double a,hz,z,r,qx,zr;
	z  = x*x;
	if (x<0) x = -x;
	hz = 0.5*z;
	r  = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
	zr = z*r;
	if (x < 0x1.33333p-2) 		     /* if |x| < 0.3 */ 
	    return one - (hz - zr);
	else {
	    if(x > 0.78125) {		/* x > 0.78125 */
		qx = 0.28125;
	    } else {
	      float f = x;
	      qx = 0.25f * f; 
	    }
	    hz = hz-qx;
	    a  = one-qx;
	    return a - (hz - zr);
	}
}