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#include <sys/endian.h>
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
42typedef __uint128_t uint128_t;
43#define	UINT128_ZERO 0ULL
44#else
45typedef struct {
46	/* Ignore endianness */
47	uint64_t u128t_word0;
48	uint64_t u128t_word1;
49} uint128_t;
50static const uint128_t very_long_zero = {0UL,0UL};
51#define	UINT128_ZERO very_long_zero
52#endif
53
54static __inline void
55uint128_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
66static __inline void
67uint128_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
81static __inline bool
82uint128_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
92static __inline int
93uint128_is_zero(uint128_t big_uint)
94{
95	return (uint128_equals(big_uint, UINT128_ZERO));
96}
97
98static __inline uint128_t
99le128dec(const void *pp)
100{
101	const uint8_t *p = pp;
102
103#ifdef USE_REAL_UINT128_T
104	return (((uint128_t)le64dec(p + 8) << 64) | le64dec(p));
105#else
106	return ((uint128_t){
107	    .u128t_word0 = le64dec(p),
108	    .u128t_word1 = le64dec(p + 8),
109	    });
110#endif
111}
112
113static __inline void
114le128enc(void *pp, uint128_t u)
115{
116	uint8_t *p = pp;
117
118#ifdef USE_REAL_UINT128_T
119	le64enc(p, (uint64_t)(u & UINT64_MAX));
120	le64enc(p + 8, (uint64_t)(u >> 64));
121#else
122	le64enc(p, u.u128t_word0);
123	le64enc(p + 8, u.u128t_word1);
124#endif
125}
126
127#endif /* SYS_DEV_RANDOM_UINT128_H_INCLUDED */
128