diff options
Diffstat (limited to 'src/base/random.hh')
| -rw-r--r-- | src/base/random.hh | 208 |
1 files changed, 39 insertions, 169 deletions
diff --git a/src/base/random.hh b/src/base/random.hh index 34107c76f..cedbd6bd4 100644 --- a/src/base/random.hh +++ b/src/base/random.hh @@ -1,4 +1,16 @@ /* + * Copyright (c) 2014 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * * Copyright (c) 2003-2005 The Regents of The University of Michigan * All rights reserved. * @@ -27,20 +39,19 @@ * * Authors: Nathan Binkert * Ali Saidi + * Andreas Hansson */ /* - * Mersenne Twister random number generator has a period of - * 2^19937-1. - * - * The actual math is in its own file to keep the license clear. + * Mersenne twister random number generator. */ #ifndef __BASE_RANDOM_HH__ #define __BASE_RANDOM_HH__ -#include <ios> +#include <random> #include <string> +#include <type_traits> #include "base/types.hh" @@ -48,192 +59,51 @@ class Checkpoint; class Random { - protected: - static const int N = 624; - static const int M = 397; - static const uint32_t MATRIX_A = (uint32_t)0x9908b0df; - static const uint32_t UPPER_MASK = (uint32_t)0x80000000; - static const uint32_t LOWER_MASK = (uint32_t)0x7fffffff; - - uint32_t mt[N]; - int mti; - - uint32_t genrand(); - uint32_t genrand(uint32_t max); - uint64_t genrand(uint64_t max); - - void - _random(int8_t &value) - { - value = genrand() & (int8_t)-1; - } - - void - _random(int16_t &value) - { - value = genrand() & (int16_t)-1; - } - - void - _random(int32_t &value) - { - value = (int32_t)genrand(); - } - - void - _random(int64_t &value) - { - value = (int64_t)genrand() << 32 | (int64_t)genrand(); - } - - void - _random(uint8_t &value) - { - value = genrand() & (uint8_t)-1; - } - void - _random(uint16_t &value) - { - value = genrand() & (uint16_t)-1; - } - - void - _random(uint32_t &value) - { - value = genrand(); - } + private: - void - _random(uint64_t &value) - { - value = (uint64_t)genrand() << 32 | (uint64_t)genrand(); - } - - // [0,1] - void - _random(float &value) - { - // ieee floats have 23 bits of mantissa - value = (genrand() >> 9) / 8388608.0; - } - - // [0,1] - void - _random(double &value) - { - double number = genrand() * 2097152.0 + (genrand() >> 11); - value = number / 9007199254740992.0; - } - - - // Range based versions of the random number generator - int8_t - _random(int8_t min, int8_t max) - { - uint32_t diff = max - min; - return static_cast<int8_t>(min + genrand(diff)); - } - - int16_t - _random(int16_t min, int16_t max) - { - uint32_t diff = max - min; - return static_cast<int16_t>(min + genrand(diff)); - } - - int32_t - _random(int32_t min, int32_t max) - { - uint32_t diff = max - min; - return static_cast<int32_t>(min + genrand(diff)); - } - - int64_t - _random(int64_t min, int64_t max) - { - uint64_t diff = max - min; - return static_cast<int64_t>(min + genrand(diff)); - } - - uint8_t - _random(uint8_t min, uint8_t max) - { - uint32_t diff = max - min; - return static_cast<uint8_t>(min + genrand(diff)); - } - - uint16_t - _random(uint16_t min, uint16_t max) - { - uint32_t diff = max - min; - return static_cast<uint16_t>(min + genrand(diff)); - } - - uint32_t - _random(uint32_t min, uint32_t max) - { - uint32_t diff = max - min; - return static_cast<uint32_t>(min + genrand(diff)); - } - - uint64_t - _random(uint64_t min, uint64_t max) - { - uint64_t diff = max - min; - return static_cast<uint64_t>(min + genrand(diff)); - } + std::mt19937_64 gen; public: + Random(); Random(uint32_t s); - Random(uint32_t init_key[], int key_length); ~Random(); void init(uint32_t s); - void init(uint32_t init_key[], int key_length); + /** + * Use the SFINAE idiom to choose an implementation based on + * whether the type is integral or floating point. + */ template <typename T> - T + typename std::enable_if<std::is_integral<T>::value, T>::type random() { - T value; - _random(value); - return value; + // [0, max_value] for integer types + std::uniform_int_distribution<T> dist; + return dist(gen); } template <typename T> - T - random(T min, T max) - { - return _random(min, max); - } - - // [0,1] - double - gen_real1() - { - return genrand() / 4294967296.0; - } - - // [0,1) - double - gen_real2() + typename std::enable_if<std::is_floating_point<T>::value, T>::type + random() { - return genrand() / 4294967295.0; + // [0, 1) for real types + std::uniform_real_distribution<T> dist; + return dist(gen); } - // (0,1) - double - gen_real3() + template <typename T> + typename std::enable_if<std::is_integral<T>::value, T>::type + random(T min, T max) { - return ((double)genrand() + 0.5) / 4294967296.0; + std::uniform_int_distribution<T> dist(min, max); + return dist(gen); } - public: - void serialize(const std::string &base, std::ostream &os); - void unserialize(const std::string &base, Checkpoint *cp, - const std::string §ion); + void serialize(std::ostream &os); + void unserialize(Checkpoint *cp, const std::string §ion); }; extern Random random_mt; |