xref: /titanic_51/usr/src/lib/libm/common/complex/carg.c (revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af)
125c28e83SPiotr Jasiukajtis /*
225c28e83SPiotr Jasiukajtis  * CDDL HEADER START
325c28e83SPiotr Jasiukajtis  *
425c28e83SPiotr Jasiukajtis  * The contents of this file are subject to the terms of the
525c28e83SPiotr Jasiukajtis  * Common Development and Distribution License (the "License").
625c28e83SPiotr Jasiukajtis  * You may not use this file except in compliance with the License.
725c28e83SPiotr Jasiukajtis  *
825c28e83SPiotr Jasiukajtis  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
925c28e83SPiotr Jasiukajtis  * or http://www.opensolaris.org/os/licensing.
1025c28e83SPiotr Jasiukajtis  * See the License for the specific language governing permissions
1125c28e83SPiotr Jasiukajtis  * and limitations under the License.
1225c28e83SPiotr Jasiukajtis  *
1325c28e83SPiotr Jasiukajtis  * When distributing Covered Code, include this CDDL HEADER in each
1425c28e83SPiotr Jasiukajtis  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
1525c28e83SPiotr Jasiukajtis  * If applicable, add the following below this CDDL HEADER, with the
1625c28e83SPiotr Jasiukajtis  * fields enclosed by brackets "[]" replaced with your own identifying
1725c28e83SPiotr Jasiukajtis  * information: Portions Copyright [yyyy] [name of copyright owner]
1825c28e83SPiotr Jasiukajtis  *
1925c28e83SPiotr Jasiukajtis  * CDDL HEADER END
2025c28e83SPiotr Jasiukajtis  */
2125c28e83SPiotr Jasiukajtis /*
2225c28e83SPiotr Jasiukajtis  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
2325c28e83SPiotr Jasiukajtis  */
2425c28e83SPiotr Jasiukajtis /*
2525c28e83SPiotr Jasiukajtis  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
2625c28e83SPiotr Jasiukajtis  * Use is subject to license terms.
2725c28e83SPiotr Jasiukajtis  */
2825c28e83SPiotr Jasiukajtis 
29*ddc0e0b5SRichard Lowe #pragma weak __carg = carg
3025c28e83SPiotr Jasiukajtis 
3125c28e83SPiotr Jasiukajtis #include <math.h>		/* atan2 */
3225c28e83SPiotr Jasiukajtis #include "complex_wrapper.h"
3325c28e83SPiotr Jasiukajtis 
3425c28e83SPiotr Jasiukajtis static const double
3525c28e83SPiotr Jasiukajtis 	pi	= 3.14159265358979311600e+00,
3625c28e83SPiotr Jasiukajtis 	pi_lo	= 1.22464679914735320717e-16;
3725c28e83SPiotr Jasiukajtis 
3825c28e83SPiotr Jasiukajtis double
3925c28e83SPiotr Jasiukajtis carg(dcomplex z) {
4025c28e83SPiotr Jasiukajtis 	int	ix, iy;
4125c28e83SPiotr Jasiukajtis 
4225c28e83SPiotr Jasiukajtis 	ix = ((int *)&(D_RE(z)))[HIWORD];
4325c28e83SPiotr Jasiukajtis 	iy = ((int *)&(D_IM(z)))[HIWORD];
4425c28e83SPiotr Jasiukajtis 	if ((((ix | iy) & ~0x80000000) | ((int *)&(D_RE(z)))[LOWORD] |
4525c28e83SPiotr Jasiukajtis 	    ((int *)&(D_IM(z)))[LOWORD]) == 0) {
4625c28e83SPiotr Jasiukajtis 		/* x and y are both zero */
4725c28e83SPiotr Jasiukajtis 		if (ix == 0)
4825c28e83SPiotr Jasiukajtis 			return (D_IM(z));
4925c28e83SPiotr Jasiukajtis 		return ((iy == 0)? pi + pi_lo : -pi - pi_lo);
5025c28e83SPiotr Jasiukajtis 	}
5125c28e83SPiotr Jasiukajtis 	return (atan2(D_IM(z), D_RE(z)));
5225c28e83SPiotr Jasiukajtis }
53