w_atan2.c (934B)
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 #ifndef lint 14 static char rcsid[] = "$FreeBSD: src/lib/msun/src/w_atan2.c,v 1.7 2002/05/28 18:15:04 alfred Exp $"; 15 #endif 16 17 /* 18 * wrapper atan2(y,x) 19 */ 20 21 #include "math.h" 22 #include "math_private.h" 23 24 25 double 26 atan2(double y, double x) /* wrapper atan2 */ 27 { 28 #ifdef _IEEE_LIBM 29 return __ieee754_atan2(y,x); 30 #else 31 double z; 32 z = __ieee754_atan2(y,x); 33 if(_LIB_VERSION == _IEEE_||isnan(x)||isnan(y)) return z; 34 if(x==0.0&&y==0.0) { 35 return __kernel_standard(y,x,3); /* atan2(+-0,+-0) */ 36 } else 37 return z; 38 #endif 39 }