imprecise.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2013 David Chisnall
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/11/lib/msun/src/imprecise.c 330897 2018-03-14 03:19:51Z eadler $
29 */
30
31#include <float.h>
32#include <math.h>
33
34/*
35 * If long double is not the same size as double, then these will lose
36 * precision and we should emit a warning whenever something links against
37 * them.
38 */
39#if (LDBL_MANT_DIG > 53)
40#define WARN_IMPRECISE(x) \
41	__warn_references(x, # x " has lower than advertised precision");
42#else
43#define WARN_IMPRECISE(x)
44#endif
45/*
46 * Declare the functions as weak variants so that other libraries providing
47 * real versions can override them.
48 */
49#define	DECLARE_WEAK(x)\
50	__weak_reference(imprecise_## x, x);\
51	WARN_IMPRECISE(x)
52
53long double
54imprecise_powl(long double x, long double y)
55{
56
57	return pow(x, y);
58}
59DECLARE_WEAK(powl);
60
61#define DECLARE_IMPRECISE(f) \
62	long double imprecise_ ## f ## l(long double v) { return f(v); }\
63	DECLARE_WEAK(f ## l)
64
65DECLARE_IMPRECISE(tgamma);
66