Line data    Source code

       1             : /*************************************************************************
       2             :  *
       3             :  *  Project
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      11             :  *      |_|
      12             :  *
      13             :  * Copyright (C) Akiel Aries, <akiel@akiel.org>, et al.
      14             :  *
      15             :  * This software is licensed as described in the file LICENSE, which
      16             :  * you should have received as part of this distribution. The terms
      17             :  * among other details are referenced in the official documentation
      18             :  * seen here : https://akielaries.github.io/openGPMP/ along with
      19             :  * important files seen in this project.
      20             :  *
      21             :  * You may opt to use, copy, modify, merge, publish, distribute
      22             :  * and/or sell copies of the Software, and permit persons to whom
      23             :  * the Software is furnished to do so, under the terms of the
      24             :  * LICENSE file. As this is an Open Source effort, all implementations
      25             :  * must be of the same methodology.
      26             :  *
      27             :  *
      28             :  *
      29             :  * This software is distributed on an AS IS basis, WITHOUT
      30             :  * WARRANTY OF ANY KIND, either express or implied.
      31             :  *
      32             :  ************************************************************************/
      33             : #include <chrono>
      34             : #include <cstdint>
      35             : #include <iostream>
      36             : #include <openGPMP/nt/random.hpp>
      37             : 
      38             : // dfault constructor
      39           1 : gpmp::core::rndm::LCG::LCG()
      40           1 :     : state(1), multiplier(6364136223846793005ULL),
      41           1 :       increment(1442695040888963407ULL) {
      42           1 : }
      43             : 
      44             : // constructor
      45           1 : gpmp::core::rndm::LCG::LCG(uint64_t seed, uint64_t a, uint64_t c)
      46           1 :     : state(seed), multiplier(a), increment(c) {
      47           1 : }
      48             : 
      49          20 : uint64_t gpmp::core::rndm::LCG::operator()() {
      50             :     // Ensure the state is non-negative
      51          20 :     state &= 0x7FFFFFFFFFFFFFFFULL;
      52             : 
      53             :     // Linear Congruential Generator algorithm
      54          20 :     state = multiplier * state + increment;
      55             : 
      56             :     // Overflow handling
      57          20 :     if (state < increment) {
      58             :         // Overflow occurred, adjust the state
      59           3 :         state += increment;
      60             :     }
      61             : 
      62          20 :     return state;
      63             : }
      64             : 
      65             : // set seed
      66           0 : void gpmp::core::rndm::LCG::seed(uint64_t new_seed) {
      67           0 :     state = new_seed;
      68           0 : }
      69             : 
      70             : // methods to retrieve parameters (optional)
      71           0 : uint64_t gpmp::core::rndm::LCG::get_multiplier() const {
      72           0 :     return multiplier;
      73             : }
      74             : 
      75           0 : uint64_t gpmp::core::rndm::LCG::get_increment() const {
      76           0 :     return increment;
      77             : }
      78             : 
      79           0 : uint64_t gpmp::core::rndm::LCG::get_seed() const {
      80           0 :     return state;
      81             : }
      82             : 
      83             : /*
      84             : uint32_t gpmp::core::rndm::LCG(uint32_t lower, uint32_t upper, uint32_t seed) {
      85             :     uint32_t mod = __32MAX;
      86             :     uint32_t mult = 1664525;
      87             :     uint32_t incr = 1013904223;
      88             : 
      89             :     // set seed = current time
      90             :     uint32_t time_seed =
      91             :         std::chrono::system_clock::now().time_since_epoch().count();
      92             : 
      93             :     uint32_t final_seed = (seed == 0) ? time_seed : seed;
      94             : 
      95             :     // Linear Congruential Generator algorithm
      96             :     uint32_t res = (mult * final_seed + incr) % mod;
      97             : 
      98             :     // trim to range
      99             :     res = lower + (res % (upper - lower + 1));
     100             : 
     101             :     return res;
     102             : }
     103             : 
     104             : uint64_t
     105             : gpmp::core::rndm::LCG_64(uint64_t lower, uint64_t upper, uint64_t seed) {
     106             :     uint64_t mod = __64MAX;
     107             :     uint64_t mult = 6364136223846793005ULL; // Large multiplier
     108             :     uint64_t incr = 1442695040888963407ULL; // Large increment
     109             : 
     110             :     // set seed = current time
     111             :     uint64_t time_seed =
     112             :         std::chrono::system_clock::now().time_since_epoch().count();
     113             : 
     114             :     uint64_t final_seed = (seed == 0) ? time_seed : seed;
     115             : 
     116             :     // Linear Congruential Generator algorithm
     117             :     uint64_t res = (mult * final_seed + incr) % mod;
     118             : 
     119             :     // Calculate the range size
     120             :     uint64_t range_size = upper - lower + 1;
     121             : 
     122             :     // Avoid division by zero
     123             :     if (range_size != 0) {
     124             :         // Ensure res is non-negative
     125             :         res = res & ((1ULL << 63) - 1);
     126             : 
     127             :         // trim to range
     128             :         res = lower + (res % range_size);
     129             :     }
     130             : 
     131             :     return res;
     132             : }*/
     133             : 
     134           0 : uint32_t gpmp::core::rndm::rotr32(uint32_t x, unsigned r) {
     135           0 :     return x >> r | x << (-r & 31);
     136             : }
     137             : 
     138           0 : uint32_t gpmp::core::rndm::pcg32(void) {
     139           0 :     uint64_t x = __PCG_STATE;
     140           0 :     unsigned count = (unsigned)(x >> 59); // 59 = 64 - 5
     141             : 
     142           0 :     __PCG_STATE = x * __PCG_MULTPLR + __PCG_INCR;
     143           0 :     x ^= x >> 18;                              // 18 = (64 - 27)/2
     144           0 :     return rotr32((uint32_t)(x >> 27), count); // 27 = 32 - 5
     145             : }
     146             : 
     147           0 : void gpmp::core::rndm::pcg32_init(uint64_t seed) {
     148           0 :     __PCG_STATE = seed + __PCG_INCR;
     149           0 :     (void)pcg32();
     150           0 : }