1*699cd480SApple OSS Distributions /*-
2*699cd480SApple OSS Distributions * Copyright (c) 2016 (Graeme Jenkinson)
3*699cd480SApple OSS Distributions * All rights reserved.
4*699cd480SApple OSS Distributions *
5*699cd480SApple OSS Distributions * This software was developed by BAE Systems, the University of Cambridge
6*699cd480SApple OSS Distributions * Computer Laboratory, and Memorial University under DARPA/AFRL contract
7*699cd480SApple OSS Distributions * FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent Computing
8*699cd480SApple OSS Distributions * (TC) research program.
9*699cd480SApple OSS Distributions *
10*699cd480SApple OSS Distributions * Redistribution and use in source and binary forms, with or without
11*699cd480SApple OSS Distributions * modification, are permitted provided that the following conditions
12*699cd480SApple OSS Distributions * are met:
13*699cd480SApple OSS Distributions * 1. Redistributions of source code must retain the above copyright
14*699cd480SApple OSS Distributions * notice, this list of conditions and the following disclaimer.
15*699cd480SApple OSS Distributions * 2. Redistributions in binary form must reproduce the above copyright
16*699cd480SApple OSS Distributions * notice, this list of conditions and the following disclaimer in the
17*699cd480SApple OSS Distributions * documentation and/or other materials provided with the distribution.
18*699cd480SApple OSS Distributions *
19*699cd480SApple OSS Distributions * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20*699cd480SApple OSS Distributions * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21*699cd480SApple OSS Distributions * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22*699cd480SApple OSS Distributions * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23*699cd480SApple OSS Distributions * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24*699cd480SApple OSS Distributions * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25*699cd480SApple OSS Distributions * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26*699cd480SApple OSS Distributions * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27*699cd480SApple OSS Distributions * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28*699cd480SApple OSS Distributions * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29*699cd480SApple OSS Distributions * SUCH DAMAGE.
30*699cd480SApple OSS Distributions *
31*699cd480SApple OSS Distributions */
32*699cd480SApple OSS Distributions
33*699cd480SApple OSS Distributions #include <sys/types.h>
34*699cd480SApple OSS Distributions
35*699cd480SApple OSS Distributions #include "dtrace_xoroshiro128_plus.h"
36*699cd480SApple OSS Distributions
37*699cd480SApple OSS Distributions static __inline uint64_t
rotl(const uint64_t x,int k)38*699cd480SApple OSS Distributions rotl(const uint64_t x, int k)
39*699cd480SApple OSS Distributions {
40*699cd480SApple OSS Distributions return (x << k) | (x >> (64 - k));
41*699cd480SApple OSS Distributions }
42*699cd480SApple OSS Distributions
43*699cd480SApple OSS Distributions /*
44*699cd480SApple OSS Distributions * This is the jump function for the generator. It is equivalent to 2^64 calls
45*699cd480SApple OSS Distributions * to next(); it can be used to generate 2^64 non-overlapping subsequences for
46*699cd480SApple OSS Distributions * parallel computations.
47*699cd480SApple OSS Distributions */
48*699cd480SApple OSS Distributions void
dtrace_xoroshiro128_plus_jump(uint64_t * const state,uint64_t * const jump_state)49*699cd480SApple OSS Distributions dtrace_xoroshiro128_plus_jump(uint64_t * const state,
50*699cd480SApple OSS Distributions uint64_t * const jump_state)
51*699cd480SApple OSS Distributions {
52*699cd480SApple OSS Distributions static const uint64_t JUMP[] = { 0xbeac0467eba5facb,
53*699cd480SApple OSS Distributions 0xd86b048b86aa9922 };
54*699cd480SApple OSS Distributions
55*699cd480SApple OSS Distributions uint64_t s0 = 0;
56*699cd480SApple OSS Distributions uint64_t s1 = 0;
57*699cd480SApple OSS Distributions size_t i = 0;
58*699cd480SApple OSS Distributions int b = 0;
59*699cd480SApple OSS Distributions for (i = 0; i < sizeof JUMP / sizeof *JUMP; i++) {
60*699cd480SApple OSS Distributions for (b = 0; b < 64; b++) {
61*699cd480SApple OSS Distributions if (JUMP[i] & 1ULL << b) {
62*699cd480SApple OSS Distributions s0 ^= state[0];
63*699cd480SApple OSS Distributions s1 ^= state[1];
64*699cd480SApple OSS Distributions }
65*699cd480SApple OSS Distributions dtrace_xoroshiro128_plus_next(state);
66*699cd480SApple OSS Distributions }
67*699cd480SApple OSS Distributions }
68*699cd480SApple OSS Distributions jump_state[0] = s0;
69*699cd480SApple OSS Distributions jump_state[1] = s1;
70*699cd480SApple OSS Distributions }
71*699cd480SApple OSS Distributions
72*699cd480SApple OSS Distributions /*
73*699cd480SApple OSS Distributions * xoroshiro128+ - XOR/rotate/shift/rotate
74*699cd480SApple OSS Distributions * xorshift.di.unimi.it
75*699cd480SApple OSS Distributions */
76*699cd480SApple OSS Distributions uint64_t
dtrace_xoroshiro128_plus_next(uint64_t * const state)77*699cd480SApple OSS Distributions dtrace_xoroshiro128_plus_next(uint64_t * const state)
78*699cd480SApple OSS Distributions {
79*699cd480SApple OSS Distributions const uint64_t s0 = state[0];
80*699cd480SApple OSS Distributions uint64_t s1 = state[1];
81*699cd480SApple OSS Distributions uint64_t result;
82*699cd480SApple OSS Distributions result = s0 + s1;
83*699cd480SApple OSS Distributions
84*699cd480SApple OSS Distributions s1 ^= s0;
85*699cd480SApple OSS Distributions state[0] = rotl(s0, 55) ^ s1 ^ (s1 << 14);
86*699cd480SApple OSS Distributions state[1] = rotl(s1, 36);
87*699cd480SApple OSS Distributions
88*699cd480SApple OSS Distributions return result;
89*699cd480SApple OSS Distributions }
90