1 /*-
2  * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 //__FBSDID("$FreeBSD: src/lib/msun/src/s_scalbln.c,v 1.2 2005/03/07 04:57:50 das Exp $");
28 
29 #include <limits.h>
30 
31 long double
scalbl(long double x,long double fn)32 scalbl (long double x, long double fn)
33 {
34     if (isnanl_inline(fn) || isnanl_inline(x))
35         return x + fn;
36 
37     if (isinf(fn)) {
38         if ((x == 0.0L && fn > 0.0L) || (isinf(x) && fn < 0.0L))
39             return __math_invalidl(fn);
40         if (fn > 0.0L)
41             return fn*x;
42         else
43             return x/(-fn);
44     }
45 
46     if (floorl(fn) != fn)
47         return __math_invalidl(fn);
48 
49     if (fn > 4.0L * __LDBL_MAX_EXP__)
50         fn = 4.0L * __LDBL_MAX_EXP__;
51 
52     if (fn < -4.0L * __LDBL_MAX_EXP__)
53         fn = -4.0L * __LDBL_MAX_EXP__;
54 
55     return scalbnl(x, (int)fn);
56 }
57