1 /*-
2 * Copyright (c) 2015 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 #define USE_REAL_UINT128_T
39 #endif
40
41 #ifdef USE_REAL_UINT128_T
42 typedef __uint128_t uint128_t;
43 #define UINT128_ZERO 0ULL
44 #else
45 typedef struct {
46 /* Ignore endianness */
47 uint64_t u128t_word0;
48 uint64_t u128t_word1;
49 } uint128_t;
50 static const uint128_t very_long_zero = {0UL,0UL};
51 #define UINT128_ZERO very_long_zero
52 #endif
53
54 static __inline void
uint128_increment(uint128_t * big_uintp)55 uint128_increment(uint128_t *big_uintp)
56 {
57 #ifdef USE_REAL_UINT128_T
58 (*big_uintp)++;
59 #else
60 big_uintp->u128t_word0++;
61 if (big_uintp->u128t_word0 == 0UL)
62 big_uintp->u128t_word1++;
63 #endif
64 }
65
66 static __inline void
uint128_add64(uint128_t * big_uintp,uint64_t add)67 uint128_add64(uint128_t *big_uintp, uint64_t add)
68 {
69 #ifdef USE_REAL_UINT128_T
70 (*big_uintp) += add;
71 #else
72 uint64_t word0p;
73
74 word0p = big_uintp->u128t_word0 + add;
75 if (word0p < big_uintp->u128t_word0)
76 big_uintp->u128t_word1++;
77 big_uintp->u128t_word0 = word0p;
78 #endif
79 }
80
81 static __inline bool
uint128_equals(uint128_t a,uint128_t b)82 uint128_equals(uint128_t a, uint128_t b)
83 {
84 #ifdef USE_REAL_UINT128_T
85 return (a == b);
86 #else
87 return (a.u128t_word0 == b.u128t_word0 &&
88 a.u128t_word1 == b.u128t_word1);
89 #endif
90 }
91
92 static __inline int
uint128_is_zero(uint128_t big_uint)93 uint128_is_zero(uint128_t big_uint)
94 {
95 return (uint128_equals(big_uint, UINT128_ZERO));
96 }
97
98 #endif /* SYS_DEV_RANDOM_UINT128_H_INCLUDED */
99