xref: /netbsd/lib/libm/src/w_atan2.c (revision b36bcf93)
1 /* @(#)w_atan2.c 5.1 93/09/24 */
2 /*
3  * ====================================================
4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5  *
6  * Developed at SunPro, a Sun Microsystems, Inc. business.
7  * Permission to use, copy, modify, and distribute this
8  * software is freely granted, provided that this notice
9  * is preserved.
10  * ====================================================
11  */
12 
13 #include <sys/cdefs.h>
14 #if defined(LIBM_SCCS) && !defined(lint)
15 __RCSID("$NetBSD: w_atan2.c,v 1.10 2007/08/10 21:20:36 drochner Exp $");
16 #endif
17 
18 /*
19  * wrapper atan2(y,x)
20  */
21 
22 #include "namespace.h"
23 #include "math.h"
24 #include "math_private.h"
25 
26 #ifdef __weak_alias
__weak_alias(atan2,_atan2)27 __weak_alias(atan2, _atan2)
28 #endif
29 
30 double
31 atan2(double y, double x)	/* wrapper atan2 */
32 {
33 #ifdef _IEEE_LIBM
34 	return __ieee754_atan2(y,x);
35 #else
36 	double z;
37 	z = __ieee754_atan2(y,x);
38 	if(_LIB_VERSION == _IEEE_||isnan(x)||isnan(y)) return z;
39 	if(x==0.0&&y==0.0) {
40 	        return __kernel_standard(y,x,3); /* atan2(+-0,+-0) */
41 	} else
42 	    return z;
43 #endif
44 }
45