Ignore:
Timestamp:
Jan 19, 2022, 2:36:56 PM (4 years ago)
Author:
Michael Brooks <mlbrooks@…>
Branches:
ADT, ast-experimental, enum, master, pthread-emulation, qualifiedEnum
Children:
97c215f
Parents:
5235d49 (diff), 6a33e40 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.
Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

File:
1 edited

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  • libcfa/src/bits/random.hfa

    r5235d49 r12c1eef  
     1//
     2// Cforall Version 1.0.0 Copyright (C) 2022 University of Waterloo
     3//
     4// The contents of this file are covered under the licence agreement in the
     5// file "LICENCE" distributed with Cforall.
     6//
     7// random.hfa --
     8//
     9// Author           : Peter A. Buhr
     10// Created On       : Fri Jan 14 07:18:11 2022
     11// Last Modified By : Peter A. Buhr
     12// Last Modified On : Fri Jan 14 07:18:58 2022
     13// Update Count     : 1
     14//
     15
    116#pragma once
    217
    318#include <stdint.h>
    419
     20// Pipelined to allow out-of-order overlap with reduced dependencies. Critically, the current random state is returned
     21// (copied), and then compute and store the next random value.
     22
     23#if defined(__SIZEOF_INT128__)
    524//--------------------------------------------------
    6 #if defined(__SIZEOF_INT128__)
    7         typedef __uint128_t __lehmer64_state_t;
    8         static inline uint64_t __lehmer64( __lehmer64_state_t & state ) {
     25        static inline uint64_t lehmer64( __uint128_t & state ) {
     26                __uint128_t ret = state;
    927                state *= 0xda942042e4dd58b5;
    10                 return state >> 64;
     28                return ret >> 64;
    1129        }
    1230
    1331//--------------------------------------------------
    14         typedef uint64_t __wyhash64_state_t;
    15         static inline uint64_t __wyhash64( __wyhash64_state_t & state ) {
     32        static inline uint64_t wyhash64( uint64_t & state ) {
    1633                state += 0x60bee2bee120fc15;
    1734                __uint128_t tmp;
    … …  
    2542
    2643//--------------------------------------------------
    27 typedef uint64_t __xorshift64_state_t;
    28 static inline uint64_t __xorshift64( __xorshift64_state_t & state ) {
    29         uint64_t x = state;
    30         x ^= x << 13;
    31         x ^= x >> 7;
    32         x ^= x << 17;
    33         return state = x;
     44static inline uint64_t xorshift_13_7_17( uint64_t & state ) {
     45        uint64_t ret = state;
     46        state ^= state << 13;
     47        state ^= state >> 7;
     48        state ^= state << 17;
     49        return ret;
    3450}
     51
     52//--------------------------------------------------
     53static inline uint32_t xorshift_6_21_7( uint32_t & state ) {
     54        uint32_t ret = state;
     55        state ^= state << 6;
     56        state ^= state >> 21;
     57        state ^= state << 7;
     58        return ret;
     59} // xorshift_6_21_7
    3560
    3661//--------------------------------------------------
    … …  
    3863  uint32_t a, b, c, d;
    3964  uint32_t counter;
    40 } __xorwow__state_t;
     65} xorwow__state_t;
    4166
    42 /* The state array must be initialized to not be all zero in the first four words */
    43 static inline uint32_t __xorwow( __xorwow__state_t & state ) {
    44         /* Algorithm "xorwow" from p. 5 of Marsaglia, "Xorshift RNGs" */
     67// The state array must be initialized to not be all zero in the first four words.
     68static inline uint32_t xorwow( xorwow__state_t & state ) {
     69        // Algorithm "xorwow" from p. 5 of Marsaglia, "Xorshift RNGs".
     70        uint32_t ret = state.a + state.counter;
    4571        uint32_t t = state.d;
    4672
    … …  
    5682
    5783        state.counter += 362437;
    58         return t + state.counter;
     84        return ret;
    5985}
     86
     87//--------------------------------------------------
     88static inline uint32_t LCG( uint32_t & state ) {                // linear congruential generator
     89        uint32_t ret = state;
     90        state = 36969 * (state & 65535) + (state >> 16);        // 36969 is NOT prime! No not change it!
     91        return ret;
     92} // LCG
     93
     94//--------------------------------------------------
     95#define M  (1_l64u << 48_l64u)
     96#define A  (25214903917_l64u)
     97#define AI (18446708753438544741_l64u)
     98#define C  (11_l64u)
     99#define D  (16_l64u)
     100
     101// Bi-directional LCG random-number generator
     102static inline uint32_t LCGBI_fwd( uint64_t & state ) {
     103        state = (A * state + C) & (M - 1);
     104        return state >> D;
     105}
     106
     107static inline uint32_t LCGBI_bck( uint64_t & state ) {
     108        unsigned int r = state >> D;
     109        state = AI * (state - C) & (M - 1);
     110        return r;
     111}
     112
     113#undef M
     114#undef A
     115#undef AI
     116#undef C
     117#undef D
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