xref: /freebsd/sys/libkern/quad.h (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This software was developed by the Computer Systems Engineering group
8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9  * contributed to Berkeley.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. 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  *	@(#)quad.h	8.1 (Berkeley) 6/4/93
36  */
37 
38 #ifndef _LIBKERN_QUAD_H_
39 #define	_LIBKERN_QUAD_H_
40 
41 /*
42  * Quad arithmetic.
43  *
44  * This library makes the following assumptions:
45  *
46  *  - The type long long (aka quad_t) exists.
47  *
48  *  - A quad variable is exactly twice as long as `long'.
49  *
50  *  - The machine's arithmetic is two's complement.
51  *
52  * This library can provide 128-bit arithmetic on a machine with 128-bit
53  * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines
54  * with 48-bit longs.
55  */
56 
57 #include <sys/cdefs.h>
58 #include <sys/types.h>
59 #include <sys/limits.h>
60 #include <sys/syslimits.h>
61 
62 /*
63  * Depending on the desired operation, we view a `long long' (aka quad_t) in
64  * one or more of the following formats.
65  */
66 union uu {
67 	quad_t	q;		/* as a (signed) quad */
68 	quad_t	uq;		/* as an unsigned quad */
69 	long	sl[2];		/* as two signed longs */
70 	u_long	ul[2];		/* as two unsigned longs */
71 };
72 
73 /*
74  * Define high and low longwords.
75  */
76 #define	H		_QUAD_HIGHWORD
77 #define	L		_QUAD_LOWWORD
78 
79 /*
80  * Total number of bits in a quad_t and in the pieces that make it up.
81  * These are used for shifting, and also below for halfword extraction
82  * and assembly.
83  */
84 #define	QUAD_BITS	(sizeof(quad_t) * CHAR_BIT)
85 #define	LONG_BITS	(sizeof(long) * CHAR_BIT)
86 #define	HALF_BITS	(sizeof(long) * CHAR_BIT / 2)
87 
88 /*
89  * Extract high and low shortwords from longword, and move low shortword of
90  * longword to upper half of long, i.e., produce the upper longword of
91  * ((quad_t)(x) << (number_of_bits_in_long/2)).  (`x' must actually be u_long.)
92  *
93  * These are used in the multiply code, to split a longword into upper
94  * and lower halves, and to reassemble a product as a quad_t, shifted left
95  * (sizeof(long)*CHAR_BIT/2).
96  */
97 #define	HHALF(x)	((x) >> HALF_BITS)
98 #define	LHALF(x)	((x) & ((1 << HALF_BITS) - 1))
99 #define	LHUP(x)		((x) << HALF_BITS)
100 
101 typedef unsigned int	qshift_t;
102 
103 quad_t		__ashldi3(quad_t, qshift_t);
104 quad_t		__ashrdi3(quad_t, qshift_t);
105 int		__cmpdi2(quad_t a, quad_t b);
106 quad_t		__divdi3(quad_t a, quad_t b);
107 quad_t		__divmoddi4(quad_t a, quad_t b, quad_t *rem);
108 quad_t		__lshrdi3(quad_t, qshift_t);
109 quad_t		__moddi3(quad_t a, quad_t b);
110 u_quad_t	__qdivrem(u_quad_t u, u_quad_t v, u_quad_t *rem);
111 u_quad_t	__udivdi3(u_quad_t a, u_quad_t b);
112 u_quad_t	__udivmoddi4(u_quad_t a, u_quad_t b, u_quad_t *rem);
113 u_quad_t	__umoddi3(u_quad_t a, u_quad_t b);
114 int		__ucmpdi2(u_quad_t a, u_quad_t b);
115 
116 /* ARM EABI support functions. */
117 #ifdef __ARM_EABI__
118 int		__aeabi_ulcmp(unsigned long long, unsigned long long);
119 #endif
120 
121 #endif /* !_LIBKERN_QUAD_H_ */
122