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
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 int
67uint128_is_zero(uint128_t big_uint)
68{
69#ifdef USE_REAL_UINT128_T
70	return (big_uint == UINT128_ZERO);
71#else
72	return (big_uint.u128t_word0 == 0UL && big_uint.u128t_word1 == 0UL);
73#endif
74}
75
76#endif /* SYS_DEV_RANDOM_UINT128_H_INCLUDED */
77