Back to index

glibc  2.9
w_atan2.c
Go to the documentation of this file.
00001 /* @(#)w_atan2.c 5.1 93/09/24 */
00002 /*
00003  * ====================================================
00004  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
00005  *
00006  * Developed at SunPro, a Sun Microsystems, Inc. business.
00007  * Permission to use, copy, modify, and distribute this
00008  * software is freely granted, provided that this notice
00009  * is preserved.
00010  * ====================================================
00011  */
00012 
00013 #if defined(LIBM_SCCS) && !defined(lint)
00014 static char rcsid[] = "$NetBSD: w_atan2.c,v 1.6 1995/05/10 20:48:39 jtc Exp $";
00015 #endif
00016 
00017 /*
00018  * wrapper atan2(y,x)
00019  */
00020 
00021 #include <math.h>
00022 #include "math_private.h"
00023 
00024 
00025 #ifdef __STDC__
00026        double __atan2(double y, double x) /* wrapper atan2 */
00027 #else
00028        double __atan2(y,x)                /* wrapper atan2 */
00029        double y,x;
00030 #endif
00031 {
00032 #ifdef _IEEE_LIBM
00033        return __ieee754_atan2(y,x);
00034 #else
00035        double z;
00036        z = __ieee754_atan2(y,x);
00037        if(_LIB_VERSION != _SVID_||__isnan(x)||__isnan(y)) return z;
00038        if(x==0.0&&y==0.0)
00039          return __kernel_standard(y,x,3); /* atan2(+-0,+-0) */
00040        return z;
00041 #endif
00042 }
00043 weak_alias (__atan2, atan2)
00044 #ifdef NO_LONG_DOUBLE
00045 strong_alias (__atan2, __atan2l)
00046 weak_alias (__atan2, atan2l)
00047 #endif