mirror of https://github.com/GOSTSec/ccminer
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
107 lines
3.1 KiB
107 lines
3.1 KiB
/* |
|
* Copyright 2008-2012 NVIDIA Corporation |
|
* |
|
* Licensed under the Apache License, Version 2.0 (the "License"); |
|
* you may not use this file except in compliance with the License. |
|
* You may obtain a copy of the License at |
|
* |
|
* http://www.apache.org/licenses/LICENSE-2.0 |
|
* |
|
* Unless required by applicable law or agreed to in writing, software |
|
* distributed under the License is distributed on an "AS IS" BASIS, |
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
* See the License for the specific language governing permissions and |
|
* limitations under the License. |
|
*/ |
|
|
|
#pragma once |
|
|
|
#include <thrust/detail/cstdint.h> |
|
#include <thrust/random/detail/mod.h> |
|
|
|
namespace thrust |
|
{ |
|
|
|
namespace random |
|
{ |
|
|
|
namespace detail |
|
{ |
|
|
|
|
|
template<typename UIntType, UIntType a, unsigned long long c, UIntType m> |
|
struct linear_congruential_engine_discard_implementation |
|
{ |
|
__host__ __device__ |
|
static void discard(UIntType &state, unsigned long long z) |
|
{ |
|
for(; z > 0; --z) |
|
{ |
|
state = detail::mod<UIntType,a,c,m>(state); |
|
} |
|
} |
|
}; // end linear_congruential_engine_discard |
|
|
|
|
|
// specialize for small integers and c == 0 |
|
// XXX figure out a robust implemenation of this for any unsigned integer type later |
|
template<thrust::detail::uint32_t a, thrust::detail::uint32_t m> |
|
struct linear_congruential_engine_discard_implementation<thrust::detail::uint32_t,a,0,m> |
|
{ |
|
__host__ __device__ |
|
static void discard(thrust::detail::uint32_t &state, unsigned long long z) |
|
{ |
|
const thrust::detail::uint32_t modulus = m; |
|
|
|
// XXX we need to use unsigned long long here or we will encounter overflow in the |
|
// multiplies below |
|
// figure out a robust implementation of this later |
|
unsigned long long multiplier = a; |
|
unsigned long long multiplier_to_z = 1; |
|
|
|
// see http://en.wikipedia.org/wiki/Modular_exponentiation |
|
while(z > 0) |
|
{ |
|
if(z & 1) |
|
{ |
|
// multiply in this bit's contribution while using modulus to keep result small |
|
multiplier_to_z = (multiplier_to_z * multiplier) % modulus; |
|
} |
|
|
|
// move to the next bit of the exponent, square (and mod) the base accordingly |
|
z >>= 1; |
|
multiplier = (multiplier * multiplier) % modulus; |
|
} |
|
|
|
state = static_cast<thrust::detail::uint32_t>((multiplier_to_z * state) % modulus); |
|
} |
|
}; // end linear_congruential_engine_discard |
|
|
|
|
|
struct linear_congruential_engine_discard |
|
{ |
|
template<typename LinearCongruentialEngine> |
|
__host__ __device__ |
|
static void discard(LinearCongruentialEngine &lcg, unsigned long long z) |
|
{ |
|
typedef typename LinearCongruentialEngine::result_type result_type; |
|
const result_type c = LinearCongruentialEngine::increment; |
|
const result_type a = LinearCongruentialEngine::multiplier; |
|
const result_type m = LinearCongruentialEngine::modulus; |
|
|
|
// XXX WAR unused variable warnings |
|
(void) c; |
|
(void) a; |
|
(void) m; |
|
|
|
linear_congruential_engine_discard_implementation<result_type,a,c,m>::discard(lcg.m_x, z); |
|
} |
|
}; // end linear_congruential_engine_discard |
|
|
|
|
|
} // end detail |
|
|
|
} // end random |
|
|
|
} // end thrust |
|
|
|
|