xref: /freebsd/lib/msun/bsdsrc/mathimpl.h (revision 0dd5a5603e7a33d976f8e6015620bbc79839c609)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 1988, 1993
5  *	The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef _MATHIMPL_H_
37 #define	_MATHIMPL_H_
38 
39 #include <math.h>
40 
41 #include "../src/math_private.h"
42 
43 /*
44  * TRUNC() is a macro that sets the trailing 27 bits in the mantissa of an
45  * IEEE double variable to zero.  It must be expression-like for syntactic
46  * reasons, and we implement this expression using an inline function
47  * instead of a pure macro to avoid depending on the gcc feature of
48  * statement-expressions.
49  */
50 #define	TRUNC(d)	(_b_trunc(&(d)))
51 
52 static __inline void
_b_trunc(volatile double * _dp)53 _b_trunc(volatile double *_dp)
54 {
55 	uint32_t _lw;
56 
57 	GET_LOW_WORD(_lw, *_dp);
58 	SET_LOW_WORD(*_dp, _lw & 0xf8000000);
59 }
60 
61 struct Double {
62 	double	a;
63 	double	b;
64 };
65 
66 /*
67  * Functions internal to the math package, yet not static.
68  */
69 double	__exp__D(double, double);
70 struct Double __log__D(double);
71 
72 #endif /* !_MATHIMPL_H_ */
73