math/w_atan2.c

   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 #if defined(LIBM_SCCS) && !defined(lint)
  14 static char rcsid[] = "$NetBSD: w_atan2.c,v 1.6 1995/05/10 20:48:39 jtc Exp $";
  15 #endif
  16
  17 /*
  18  * wrapper atan2(y,x)
  19  */
  20
  21 #include <math.h>
  22 #include "math_private.h"
  23
  24
  25 #ifdef __STDC__
  26         double __atan2(double y, double x)      /* wrapper atan2 */
  27 #else
  28         double __atan2(y,x)                     /* wrapper atan2 */
  29         double y,x;
  30 #endif
  31 {
  32 #ifdef _IEEE_LIBM
  33         return __ieee754_atan2(y,x);
  34 #else
  35         double z;
  36         z = __ieee754_atan2(y,x);
  37         if(_LIB_VERSION != _SVID_||__isnan(x)||__isnan(y)) return z;
  38         if(x==0.0&&y==0.0)
  39           return __kernel_standard(y,x,3); /* atan2(+-0,+-0) */
  40         return z;
  41 #endif
  42 }
  43 weak_alias (__atan2, atan2)
  44 #ifdef NO_LONG_DOUBLE
  45 strong_alias (__atan2, __atan2l)
  46 weak_alias (__atan2, atan2l)
  47 #endif