RTAI API: base/math/w_atan2.c Source 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 #include "math.h"
00021 #include "mathP.h"
00022 
00023 
00024 #ifdef __STDC__
00025     double atan2(double y, double x)    /* wrapper atan2 */
00026 #else
00027     double atan2(y,x)           /* wrapper atan2 */
00028     double y,x;
00029 #endif
00030 {
00031 #ifdef _IEEE_LIBM
00032     return __ieee754_atan2(y,x);
00033 #else
00034     double z;
00035     z = __ieee754_atan2(y,x);
00036     if(_LIB_VERSION == _IEEE_||isnan(x)||isnan(y)) return z;
00037     if(x==0.0&&y==0.0) {
00038             return __kernel_standard(y,x,3); /* atan2(+-0,+-0) */
00039     } else
00040         return z;
00041 #endif
00042 }