FreeBSD/Linux Kernel Cross Reference
sys/libkern/quad.h
1 /*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This software was developed by the Computer Systems Engineering group
6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7 * contributed to Berkeley.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)quad.h 8.1 (Berkeley) 6/4/93
34 * $FreeBSD: src/sys/libkern/quad.h,v 1.19 2008/02/23 22:40:05 marcel Exp $
35 */
36
37 #ifndef _LIBKERN_QUAD_H_
38 #define _LIBKERN_QUAD_H_
39
40 /*
41 * Quad arithmetic.
42 *
43 * This library makes the following assumptions:
44 *
45 * - The type long long (aka quad_t) exists.
46 *
47 * - A quad variable is exactly twice as long as `long'.
48 *
49 * - The machine's arithmetic is two's complement.
50 *
51 * This library can provide 128-bit arithmetic on a machine with 128-bit
52 * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines
53 * with 48-bit longs.
54 */
55
56 #include <sys/cdefs.h>
57 #include <sys/types.h>
58 #include <sys/limits.h>
59 #include <sys/syslimits.h>
60
61 /*
62 * Depending on the desired operation, we view a `long long' (aka quad_t) in
63 * one or more of the following formats.
64 */
65 union uu {
66 quad_t q; /* as a (signed) quad */
67 quad_t uq; /* as an unsigned quad */
68 long sl[2]; /* as two signed longs */
69 u_long ul[2]; /* as two unsigned longs */
70 };
71
72 /*
73 * Define high and low longwords.
74 */
75 #define H _QUAD_HIGHWORD
76 #define L _QUAD_LOWWORD
77
78 /*
79 * Total number of bits in a quad_t and in the pieces that make it up.
80 * These are used for shifting, and also below for halfword extraction
81 * and assembly.
82 */
83 #define QUAD_BITS (sizeof(quad_t) * CHAR_BIT)
84 #define LONG_BITS (sizeof(long) * CHAR_BIT)
85 #define HALF_BITS (sizeof(long) * CHAR_BIT / 2)
86
87 /*
88 * Extract high and low shortwords from longword, and move low shortword of
89 * longword to upper half of long, i.e., produce the upper longword of
90 * ((quad_t)(x) << (number_of_bits_in_long/2)). (`x' must actually be u_long.)
91 *
92 * These are used in the multiply code, to split a longword into upper
93 * and lower halves, and to reassemble a product as a quad_t, shifted left
94 * (sizeof(long)*CHAR_BIT/2).
95 */
96 #define HHALF(x) ((x) >> HALF_BITS)
97 #define LHALF(x) ((x) & ((1 << HALF_BITS) - 1))
98 #define LHUP(x) ((x) << HALF_BITS)
99
100 typedef unsigned int qshift_t;
101
102 quad_t __ashldi3(quad_t, qshift_t);
103 quad_t __ashrdi3(quad_t, qshift_t);
104 int __cmpdi2(quad_t a, quad_t b);
105 quad_t __divdi3(quad_t a, quad_t b);
106 quad_t __lshrdi3(quad_t, qshift_t);
107 quad_t __moddi3(quad_t a, quad_t b);
108 u_quad_t __qdivrem(u_quad_t u, u_quad_t v, u_quad_t *rem);
109 u_quad_t __udivdi3(u_quad_t a, u_quad_t b);
110 u_quad_t __umoddi3(u_quad_t a, u_quad_t b);
111 int __ucmpdi2(u_quad_t a, u_quad_t b);
112
113 #endif /* !_LIBKERN_QUAD_H_ */
114
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