xref: /freebsd/sys/dev/random/uint128.h (revision a812392203d7c4c3f0db9d8a0f3391374c49c71f)
1 /*-
2  * Copyright (c) 2014 Mark R V Murray
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef SYS_DEV_RANDOM_UINT128_H_INCLUDED
30 #define SYS_DEV_RANDOM_UINT128_H_INCLUDED
31 
32 /* This whole thing is a crock :-(
33  *
34  * Everyone knows you always need the __uint128_t types!
35  */
36 
37 #ifdef __SIZEOF_INT128__
38 typedef __uint128_t uint128_t;
39 #else
40 typedef uint64_t uint128_t[2];
41 #endif
42 
43 static __inline void
44 uint128_clear(uint128_t *big_uint)
45 {
46 #ifdef __SIZEOF_INT128__
47 	(*big_uint) = 0ULL;
48 #else
49 	(*big_uint)[0] = (*big_uint)[1] = 0UL;
50 #endif
51 }
52 
53 static __inline void
54 uint128_increment(uint128_t *big_uint)
55 {
56 #ifdef __SIZEOF_INT128__
57 	(*big_uint)++;
58 #else
59 	(*big_uint)[0]++;
60 	if ((*big_uint)[0] == 0UL)
61 		(*big_uint)[1]++;
62 #endif
63 }
64 
65 static __inline int
66 uint128_is_zero(uint128_t big_uint)
67 {
68 #ifdef __SIZEOF_INT128__
69 	return (big_uint == 0ULL);
70 #else
71 	return (big_uint[0] == 0UL && big_uint[1] == 0UL);
72 #endif
73 }
74 
75 #endif /* SYS_DEV_RANDOM_UINT128_H_INCLUDED */
76