1 /*-
2  * Copyright (c) 2013 David Chisnall
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  * $FreeBSD$
27  */
28 
29 #include <float.h>
30 #include <math.h>
31 
32 /*
33  * If long double is not the same size as double, then these will lose
34  * precision and we should emit a warning whenever something links against
35  * them.
36  */
37 #if (LDBL_MANT_DIG > 53)
38 #define WARN_IMPRECISE(x) \
39 	__warn_references(x, # x " has lower than advertised precision");
40 #else
41 #define WARN_IMPRECISE(x)
42 #endif
43 /*
44  * Declare the functions as weak variants so that other libraries providing
45  * real versions can override them.
46  */
47 #define	DECLARE_WEAK(x)\
48 	__weak_reference(imprecise_## x, x);\
49 	WARN_IMPRECISE(x)
50 
51 long double
imprecise_powl(long double x,long double y)52 imprecise_powl(long double x, long double y)
53 {
54 
55 	return pow(x, y);
56 }
57 DECLARE_WEAK(powl);
58 
59 #define DECLARE_IMPRECISE(f) \
60 	long double imprecise_ ## f ## l(long double v) { return f(v); }\
61 	DECLARE_WEAK(f ## l)
62 
63 DECLARE_IMPRECISE(tgamma);
64