1 
2 /*
3  * Copyright (c) 1998, 2001, Oracle and/or its affiliates. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.  Oracle designates this
9  * particular file as subject to the "Classpath" exception as provided
10  * by Oracle in the LICENSE file that accompanied this code.
11  *
12  * This code is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15  * version 2 for more details (a copy is included in the LICENSE file that
16  * accompanied this code).
17  *
18  * You should have received a copy of the GNU General Public License version
19  * 2 along with this work; if not, write to the Free Software Foundation,
20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21  *
22  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23  * or visit www.oracle.com if you need additional information or have any
24  * questions.
25  */
26 
27 /*
28  * wrapper log(x)
29  */
30 
31 #include "fdlibm.h"
32 
33 
34 #ifdef __STDC__
log(double x)35         double log(double x)            /* wrapper log */
36 #else
37         double log(x)                   /* wrapper log */
38         double x;
39 #endif
40 {
41 #ifdef _IEEE_LIBM
42         return __ieee754_log(x);
43 #else
44         double z;
45         z = __ieee754_log(x);
46         if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z;
47         if(x==0.0)
48             return __kernel_standard(x,x,16); /* log(0) */
49         else
50             return __kernel_standard(x,x,17); /* log(x<0) */
51 #endif
52 }
53