1 /* @(#)w_log.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 #include <sys/cdefs.h> 14 #if defined(LIBM_SCCS) && !defined(lint) 15 __RCSID("$NetBSD: w_log.c,v 1.10 2007/08/20 16:01:40 drochner Exp $"); 16 #endif 17 18 /* 19 * wrapper log(x) 20 */ 21 22 #include "namespace.h" 23 #include "math.h" 24 #include "math_private.h" 25 26 #ifdef __weak_alias 27 __weak_alias(log, _log) 28 #endif 29 30 double 31 log(double x) /* wrapper log */ 32 { 33 #ifdef _IEEE_LIBM 34 return __ieee754_log(x); 35 #else 36 double z; 37 z = __ieee754_log(x); 38 if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z; 39 if(x==0.0) 40 return __kernel_standard(x,x,16); /* log(0) */ 41 else 42 return __kernel_standard(x,x,17); /* log(x<0) */ 43 #endif 44 } 45