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 1.11 2024/07/16 14:52:50 riastradh Exp $"); 16 #endif 17 18 /* 19 * wrapper log(x) 20 */ 21 22 #include "namespace.h" 23 24 #include "math.h" 25 #include "math_private.h" 26 27 #ifndef __HAVE_LONG_DOUBLE 28 __weak_alias(logl, _logl) 29 __strong_alias(_logl, _log) 30 #endif 31 32 __weak_alias(log, _log) 33 double 34 log(double x) /* wrapper log */ 35 { 36 #ifdef _IEEE_LIBM 37 return __ieee754_log(x); 38 #else 39 double z; 40 z = __ieee754_log(x); 41 if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z; 42 if(x==0.0) 43 return __kernel_standard(x,x,16); /* log(0) */ 44 else 45 return __kernel_standard(x,x,17); /* log(x<0) */ 46 #endif 47 } 48