The friendly Operating System for the Internet of Things
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  * 3. 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  * $OpenBSD: quad.h,v 1.7 2009/11/07 23:09:35 jsg Exp $
34  */
35 
36 /*
37  * Quad arithmetic.
38  *
39  * This library makes the following assumptions:
40  *
41  * - The type long long (aka quad_t) exists.
42  *
43  * - A quad variable is exactly twice as long as `int'.
44  *
45  * - The machine's arithmetic is two's complement.
46  *
47  * This library can provide 128-bit arithmetic on a machine with 128-bit
48  * quads and 64-bit ints, for instance, or 96-bit arithmetic on machines
49  * with 48-bit ints.
50  */
51 
52 #include <sys/types.h>
53 #include <limits.h>
54 
55 #include <machine/endian.h>
56 
57 #ifdef __cplusplus
58 extern "C" {
59 #endif
60 
61 typedef char ___QUAD_ASSERT__LENGHTS[sizeof (long long) == 2*sizeof (int) ? +1 : -1];
62 typedef char ___QUAD_ASSERT__2COMPLEMENT[-1234 == (~1234 + 1) ? +1 : -1];
63 
64 typedef long long quad_t;
65 typedef unsigned long long u_quad_t;
66 
67 /*
68  * Define high and low parts of a quad_t.
69  */
70 
71 #if BYTE_ORDER == LITTLE_ENDIAN
72 # define L (0)
73 # define H (1)
74 #elif BYTE_ORDER == BIG_ENDIAN
75 # define L (1)
76 # define H (0)
77 #else
78 # error "BYTE_ORDER must be either LITTLE_ENDIAN or BIG_ENDIAN!"
79 #endif
80 
81 #define QUAD_MIN (LLONG_MIN)
82 #define QUAD_MAX (LLONG_MAX)
83 #define UQUAD_MAX (ULLONG_MAX)
84 
89 union uu {
90  quad_t q;
91  u_quad_t uq;
92  int sl[2];
93  u_int ul[2];
94 };
95 
96 /*
97  * Total number of bits in a quad_t and in the pieces that make it up.
98  * These are used for shifting, and also below for halfword extraction
99  * and assembly.
100  */
101 #define QUAD_BITS (sizeof(quad_t) * CHAR_BIT)
102 #define INT_BITS (sizeof(int) * CHAR_BIT)
103 #define HALF_BITS (sizeof(int) * CHAR_BIT / 2)
104 
105 /*
106  * Extract high and low shortwords from longword, and move low shortword of
107  * longword to upper half of long, i.e., produce the upper longword of
108  * ((quad_t)(x) << (number_of_bits_in_int/2)). (`x' must actually be u_int.)
109  *
110  * These are used in the multiply code, to split a longword into upper
111  * and lower halves, and to reassemble a product as a quad_t, shifted left
112  * (sizeof(int)*CHAR_BIT/2).
113  */
114 #define HHALF(x) ((u_int) (x) >> HALF_BITS)
115 #define LHALF(x) ((u_int) (x) & (((int) 1 << HALF_BITS) - 1))
116 #define LHUP(x) ((u_int) (x) << HALF_BITS)
117 
118 typedef unsigned int qshift_t;
119 
120 quad_t __adddi3(quad_t, quad_t);
121 quad_t __anddi3(quad_t, quad_t);
122 quad_t __ashldi3(quad_t, qshift_t);
123 quad_t __ashrdi3(quad_t, qshift_t);
124 int __cmpdi2(quad_t, quad_t);
125 quad_t __divdi3(quad_t, quad_t);
126 quad_t __fixdfdi(double);
127 quad_t __fixsfdi(float);
128 u_quad_t __fixunsdfdi(double);
129 u_quad_t __fixunssfdi(float);
130 double __floatdidf(quad_t);
131 float __floatdisf(quad_t);
132 double __floatunsdidf(u_quad_t);
133 quad_t __iordi3(quad_t, quad_t);
134 quad_t __lshldi3(quad_t, qshift_t);
135 quad_t __lshrdi3(quad_t, qshift_t);
136 quad_t __moddi3(quad_t, quad_t);
137 quad_t __muldi3(quad_t, quad_t);
138 quad_t __negdi2(quad_t);
139 quad_t __one_cmpldi2(quad_t);
140 u_quad_t __qdivrem(u_quad_t, u_quad_t, u_quad_t *);
141 quad_t __subdi3(quad_t, quad_t);
142 int __ucmpdi2(u_quad_t, u_quad_t);
143 u_quad_t __udivdi3(u_quad_t, u_quad_t );
144 u_quad_t __umoddi3(u_quad_t, u_quad_t );
145 quad_t __xordi3(quad_t, quad_t);
146 
147 #ifdef __cplusplus
148 }
149 #endif
Depending on the desired operation, we view a `long long' (aka quad_t) in one or more of the followin...
Definition: quad.h:89
quad_t q
as a (signed) quad
Definition: quad.h:90
u_quad_t uq
as an unsigned quad
Definition: quad.h:91
u_int ul[2]
as two unsigned ints
Definition: quad.h:93
int sl[2]
as two signed ints
Definition: quad.h:92