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[] = "$Id: w_atan2.c,v 1.5 1994/09/22 16:45:25 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 == _IEEE_||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 } else 41 return z; 42 #endif 43 } 44