diff options
Diffstat (limited to 'math/w_log.c')
| -rw-r--r-- | math/w_log.c | 69 |
1 files changed, 35 insertions, 34 deletions
diff --git a/math/w_log.c b/math/w_log.c index 7e9afdf..b43af79 100644 --- a/math/w_log.c +++ b/math/w_log.c @@ -1,45 +1,46 @@ -/* @(#)w_log.c 5.1 93/09/24 */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunPro, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - */ +/* Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: w_log.c,v 1.6 1995/05/10 20:49:33 jtc Exp $"; -#endif + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. -/* - * wrapper log(x) - */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ +#include <fenv.h> #include <math.h> #include <math_private.h> -#ifdef __STDC__ - double __log(double x) /* wrapper log */ -#else - double __log(x) /* wrapper log */ - double x; -#endif +/* wrapper log(x) */ +double +__log (double x) { -#ifdef _IEEE_LIBM - return __ieee754_log(x); -#else - double z; - z = __ieee754_log(x); - if(_LIB_VERSION == _IEEE_ || __isnan(x) || x > 0.0) return z; - if(x==0.0) - return __kernel_standard(x,x,16); /* log(0) */ - else - return __kernel_standard(x,x,17); /* log(x<0) */ -#endif + if (__builtin_expect (x <= 0.0, 0) && _LIB_VERSION != _IEEE_) + { + if (x == 0.0) + { + feraiseexcept (FE_DIVBYZERO); + return __kernel_standard (x, x, 16); /* log(0) */ + } + else + { + feraiseexcept (FE_INVALID); + return __kernel_standard (x, x, 17); /* log(x<0) */ + } + } + + return __ieee754_log (x); } weak_alias (__log, log) #ifdef NO_LONG_DOUBLE |