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
27 #ifndef SYS_DEV_RANDOM_UINT128_H_INCLUDED
28 #define SYS_DEV_RANDOM_UINT128_H_INCLUDED
29
30 /* This whole thing is a crock :-(
31 *
32 * Everyone knows you always need the __uint128_t types!
33 */
34
35 #ifdef __SIZEOF_INT128__
36 #define USE_REAL_UINT128_T
37 #endif
38
39 #ifdef USE_REAL_UINT128_T
40 typedef __uint128_t uint128_t;
41 #define UINT128_ZERO 0ULL
42 #else
43 typedef struct {
44 /* Ignore endianness */
45 uint64_t u128t_word0;
46 uint64_t u128t_word1;
47 } uint128_t;
48 static const uint128_t very_long_zero = {0UL,0UL};
49 #define UINT128_ZERO very_long_zero
50 #endif
51
52 static __inline void
uint128_increment(uint128_t * big_uintp)53 uint128_increment(uint128_t *big_uintp)
54 {
55 #ifdef USE_REAL_UINT128_T
56 (*big_uintp)++;
57 #else
58 big_uintp->u128t_word0++;
59 if (big_uintp->u128t_word0 == 0UL)
60 big_uintp->u128t_word1++;
61 #endif
62 }
63
64 static __inline void
uint128_add64(uint128_t * big_uintp,uint64_t add)65 uint128_add64(uint128_t *big_uintp, uint64_t add)
66 {
67 #ifdef USE_REAL_UINT128_T
68 (*big_uintp) += add;
69 #else
70 uint64_t word0p;
71
72 word0p = big_uintp->u128t_word0 + add;
73 if (word0p < big_uintp->u128t_word0)
74 big_uintp->u128t_word1++;
75 big_uintp->u128t_word0 = word0p;
76 #endif
77 }
78
79 static __inline bool
uint128_equals(uint128_t a,uint128_t b)80 uint128_equals(uint128_t a, uint128_t b)
81 {
82 #ifdef USE_REAL_UINT128_T
83 return (a == b);
84 #else
85 return (a.u128t_word0 == b.u128t_word0 &&
86 a.u128t_word1 == b.u128t_word1);
87 #endif
88 }
89
90 static __inline int
uint128_is_zero(uint128_t big_uint)91 uint128_is_zero(uint128_t big_uint)
92 {
93 return (uint128_equals(big_uint, UINT128_ZERO));
94 }
95
96 #endif /* SYS_DEV_RANDOM_UINT128_H_INCLUDED */
97