| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___RANDOM_LINEAR_CONGRUENTIAL_ENGINE_H |
| #define _LIBCPP___RANDOM_LINEAR_CONGRUENTIAL_ENGINE_H |
| |
| #include <__config> |
| #include <__random/is_seed_sequence.h> |
| #include <__type_traits/enable_if.h> |
| #include <__type_traits/integral_constant.h> |
| #include <__type_traits/is_unsigned.h> |
| #include <cstdint> |
| #include <iosfwd> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| enum __lce_alg_type { |
| _LCE_Full, |
| _LCE_Part, |
| _LCE_Schrage, |
| _LCE_Promote, |
| }; |
| |
| template <unsigned long long __a, |
| unsigned long long __c, |
| unsigned long long __m, |
| unsigned long long _Mp, |
| bool _HasOverflow = (__a != 0ull && (__m & (__m - 1ull)) != 0ull), // a != 0, m != 0, m != 2^n |
| bool _Full = (!_HasOverflow || __m - 1ull <= (_Mp - __c) / __a), // (a * x + c) % m works |
| bool _Part = (!_HasOverflow || __m - 1ull <= _Mp / __a), // (a * x) % m works |
| bool _Schrage = (_HasOverflow && __m % __a <= __m / __a)> // r <= q |
| struct __lce_alg_picker { |
| static _LIBCPP_CONSTEXPR const __lce_alg_type __mode = |
| _Full ? _LCE_Full |
| : _Part ? _LCE_Part |
| : _Schrage ? _LCE_Schrage |
| : _LCE_Promote; |
| |
| #ifdef _LIBCPP_HAS_NO_INT128 |
| static_assert(_Mp != (unsigned long long)(-1) || _Full || _Part || _Schrage, |
| "The current values for a, c, and m are not currently supported on platforms without __int128"); |
| #endif |
| }; |
| |
| template <unsigned long long __a, |
| unsigned long long __c, |
| unsigned long long __m, |
| unsigned long long _Mp, |
| __lce_alg_type _Mode = __lce_alg_picker<__a, __c, __m, _Mp>::__mode> |
| struct __lce_ta; |
| |
| // 64 |
| |
| #ifndef _LIBCPP_HAS_NO_INT128 |
| template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp> |
| struct __lce_ta<_Ap, _Cp, _Mp, (unsigned long long)(-1), _LCE_Promote> { |
| typedef unsigned long long result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __xp) { |
| __extension__ using __calc_type = unsigned __int128; |
| const __calc_type __a = static_cast<__calc_type>(_Ap); |
| const __calc_type __c = static_cast<__calc_type>(_Cp); |
| const __calc_type __m = static_cast<__calc_type>(_Mp); |
| const __calc_type __x = static_cast<__calc_type>(__xp); |
| return static_cast<result_type>((__a * __x + __c) % __m); |
| } |
| }; |
| #endif |
| |
| template <unsigned long long __a, unsigned long long __c, unsigned long long __m> |
| struct __lce_ta<__a, __c, __m, (unsigned long long)(-1), _LCE_Schrage> { |
| typedef unsigned long long result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| // Schrage's algorithm |
| const result_type __q = __m / __a; |
| const result_type __r = __m % __a; |
| const result_type __t0 = __a * (__x % __q); |
| const result_type __t1 = __r * (__x / __q); |
| __x = __t0 + (__t0 < __t1) * __m - __t1; |
| __x += __c - (__x >= __m - __c) * __m; |
| return __x; |
| } |
| }; |
| |
| template <unsigned long long __a, unsigned long long __m> |
| struct __lce_ta<__a, 0ull, __m, (unsigned long long)(-1), _LCE_Schrage> { |
| typedef unsigned long long result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| // Schrage's algorithm |
| const result_type __q = __m / __a; |
| const result_type __r = __m % __a; |
| const result_type __t0 = __a * (__x % __q); |
| const result_type __t1 = __r * (__x / __q); |
| __x = __t0 + (__t0 < __t1) * __m - __t1; |
| return __x; |
| } |
| }; |
| |
| template <unsigned long long __a, unsigned long long __c, unsigned long long __m> |
| struct __lce_ta<__a, __c, __m, (unsigned long long)(-1), _LCE_Part> { |
| typedef unsigned long long result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| // Use (((a*x) % m) + c) % m |
| __x = (__a * __x) % __m; |
| __x += __c - (__x >= __m - __c) * __m; |
| return __x; |
| } |
| }; |
| |
| template <unsigned long long __a, unsigned long long __c, unsigned long long __m> |
| struct __lce_ta<__a, __c, __m, (unsigned long long)(-1), _LCE_Full> { |
| typedef unsigned long long result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { return (__a * __x + __c) % __m; } |
| }; |
| |
| template <unsigned long long __a, unsigned long long __c> |
| struct __lce_ta<__a, __c, 0ull, (unsigned long long)(-1), _LCE_Full> { |
| typedef unsigned long long result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { return __a * __x + __c; } |
| }; |
| |
| // 32 |
| |
| template <unsigned long long __a, unsigned long long __c, unsigned long long __m> |
| struct __lce_ta<__a, __c, __m, unsigned(-1), _LCE_Promote> { |
| typedef unsigned result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| return static_cast<result_type>(__lce_ta<__a, __c, __m, (unsigned long long)(-1)>::next(__x)); |
| } |
| }; |
| |
| template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp> |
| struct __lce_ta<_Ap, _Cp, _Mp, unsigned(-1), _LCE_Schrage> { |
| typedef unsigned result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| const result_type __a = static_cast<result_type>(_Ap); |
| const result_type __c = static_cast<result_type>(_Cp); |
| const result_type __m = static_cast<result_type>(_Mp); |
| // Schrage's algorithm |
| const result_type __q = __m / __a; |
| const result_type __r = __m % __a; |
| const result_type __t0 = __a * (__x % __q); |
| const result_type __t1 = __r * (__x / __q); |
| __x = __t0 + (__t0 < __t1) * __m - __t1; |
| __x += __c - (__x >= __m - __c) * __m; |
| return __x; |
| } |
| }; |
| |
| template <unsigned long long _Ap, unsigned long long _Mp> |
| struct __lce_ta<_Ap, 0ull, _Mp, unsigned(-1), _LCE_Schrage> { |
| typedef unsigned result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| const result_type __a = static_cast<result_type>(_Ap); |
| const result_type __m = static_cast<result_type>(_Mp); |
| // Schrage's algorithm |
| const result_type __q = __m / __a; |
| const result_type __r = __m % __a; |
| const result_type __t0 = __a * (__x % __q); |
| const result_type __t1 = __r * (__x / __q); |
| __x = __t0 + (__t0 < __t1) * __m - __t1; |
| return __x; |
| } |
| }; |
| |
| template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp> |
| struct __lce_ta<_Ap, _Cp, _Mp, unsigned(-1), _LCE_Part> { |
| typedef unsigned result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| const result_type __a = static_cast<result_type>(_Ap); |
| const result_type __c = static_cast<result_type>(_Cp); |
| const result_type __m = static_cast<result_type>(_Mp); |
| // Use (((a*x) % m) + c) % m |
| __x = (__a * __x) % __m; |
| __x += __c - (__x >= __m - __c) * __m; |
| return __x; |
| } |
| }; |
| |
| template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp> |
| struct __lce_ta<_Ap, _Cp, _Mp, unsigned(-1), _LCE_Full> { |
| typedef unsigned result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| const result_type __a = static_cast<result_type>(_Ap); |
| const result_type __c = static_cast<result_type>(_Cp); |
| const result_type __m = static_cast<result_type>(_Mp); |
| return (__a * __x + __c) % __m; |
| } |
| }; |
| |
| template <unsigned long long _Ap, unsigned long long _Cp> |
| struct __lce_ta<_Ap, _Cp, 0ull, unsigned(-1), _LCE_Full> { |
| typedef unsigned result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| const result_type __a = static_cast<result_type>(_Ap); |
| const result_type __c = static_cast<result_type>(_Cp); |
| return __a * __x + __c; |
| } |
| }; |
| |
| // 16 |
| |
| template <unsigned long long __a, unsigned long long __c, unsigned long long __m, __lce_alg_type __mode> |
| struct __lce_ta<__a, __c, __m, (unsigned short)(-1), __mode> { |
| typedef unsigned short result_type; |
| _LIBCPP_HIDE_FROM_ABI static result_type next(result_type __x) { |
| return static_cast<result_type>(__lce_ta<__a, __c, __m, unsigned(-1)>::next(__x)); |
| } |
| }; |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| class _LIBCPP_TEMPLATE_VIS linear_congruential_engine; |
| |
| template <class _CharT, class _Traits, class _Up, _Up _Ap, _Up _Cp, _Up _Np> |
| _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& |
| operator<<(basic_ostream<_CharT, _Traits>& __os, const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&); |
| |
| template <class _CharT, class _Traits, class _Up, _Up _Ap, _Up _Cp, _Up _Np> |
| _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& |
| operator>>(basic_istream<_CharT, _Traits>& __is, linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x); |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| class _LIBCPP_TEMPLATE_VIS linear_congruential_engine { |
| public: |
| // types |
| typedef _UIntType result_type; |
| |
| private: |
| result_type __x_; |
| |
| static _LIBCPP_CONSTEXPR const result_type _Mp = result_type(-1); |
| |
| static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters"); |
| static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters"); |
| static_assert(is_unsigned<_UIntType>::value, "_UIntType must be unsigned type"); |
| |
| public: |
| static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u : 0u; |
| static _LIBCPP_CONSTEXPR const result_type _Max = __m - _UIntType(1u); |
| static_assert(_Min < _Max, "linear_congruential_engine invalid parameters"); |
| |
| // engine characteristics |
| static _LIBCPP_CONSTEXPR const result_type multiplier = __a; |
| static _LIBCPP_CONSTEXPR const result_type increment = __c; |
| static _LIBCPP_CONSTEXPR const result_type modulus = __m; |
| _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR result_type min() { return _Min; } |
| _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR result_type max() { return _Max; } |
| static _LIBCPP_CONSTEXPR const result_type default_seed = 1u; |
| |
| // constructors and seeding functions |
| #ifndef _LIBCPP_CXX03_LANG |
| _LIBCPP_HIDE_FROM_ABI linear_congruential_engine() : linear_congruential_engine(default_seed) {} |
| _LIBCPP_HIDE_FROM_ABI explicit linear_congruential_engine(result_type __s) { seed(__s); } |
| #else |
| _LIBCPP_HIDE_FROM_ABI explicit linear_congruential_engine(result_type __s = default_seed) { seed(__s); } |
| #endif |
| template <class _Sseq, __enable_if_t<__is_seed_sequence<_Sseq, linear_congruential_engine>::value, int> = 0> |
| _LIBCPP_HIDE_FROM_ABI explicit linear_congruential_engine(_Sseq& __q) { |
| seed(__q); |
| } |
| _LIBCPP_HIDE_FROM_ABI void seed(result_type __s = default_seed) { |
| seed(integral_constant<bool, __m == 0>(), integral_constant<bool, __c == 0>(), __s); |
| } |
| template <class _Sseq, __enable_if_t<__is_seed_sequence<_Sseq, linear_congruential_engine>::value, int> = 0> |
| _LIBCPP_HIDE_FROM_ABI void seed(_Sseq& __q) { |
| __seed( |
| __q, |
| integral_constant<unsigned, |
| 1 + (__m == 0 ? (sizeof(result_type) * __CHAR_BIT__ - 1) / 32 : (__m > 0x100000000ull))>()); |
| } |
| |
| // generating functions |
| _LIBCPP_HIDE_FROM_ABI result_type operator()() { |
| return __x_ = static_cast<result_type>(__lce_ta<__a, __c, __m, _Mp>::next(__x_)); |
| } |
| _LIBCPP_HIDE_FROM_ABI void discard(unsigned long long __z) { |
| for (; __z; --__z) |
| operator()(); |
| } |
| |
| friend _LIBCPP_HIDE_FROM_ABI bool |
| operator==(const linear_congruential_engine& __x, const linear_congruential_engine& __y) { |
| return __x.__x_ == __y.__x_; |
| } |
| friend _LIBCPP_HIDE_FROM_ABI bool |
| operator!=(const linear_congruential_engine& __x, const linear_congruential_engine& __y) { |
| return !(__x == __y); |
| } |
| |
| private: |
| _LIBCPP_HIDE_FROM_ABI void seed(true_type, true_type, result_type __s) { __x_ = __s == 0 ? 1 : __s; } |
| _LIBCPP_HIDE_FROM_ABI void seed(true_type, false_type, result_type __s) { __x_ = __s; } |
| _LIBCPP_HIDE_FROM_ABI void seed(false_type, true_type, result_type __s) { __x_ = __s % __m == 0 ? 1 : __s % __m; } |
| _LIBCPP_HIDE_FROM_ABI void seed(false_type, false_type, result_type __s) { __x_ = __s % __m; } |
| |
| template <class _Sseq> |
| _LIBCPP_HIDE_FROM_ABI void __seed(_Sseq& __q, integral_constant<unsigned, 1>); |
| template <class _Sseq> |
| _LIBCPP_HIDE_FROM_ABI void __seed(_Sseq& __q, integral_constant<unsigned, 2>); |
| |
| template <class _CharT, class _Traits, class _Up, _Up _Ap, _Up _Cp, _Up _Np> |
| friend basic_ostream<_CharT, _Traits>& |
| operator<<(basic_ostream<_CharT, _Traits>& __os, const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&); |
| |
| template <class _CharT, class _Traits, class _Up, _Up _Ap, _Up _Cp, _Up _Np> |
| friend basic_istream<_CharT, _Traits>& |
| operator>>(basic_istream<_CharT, _Traits>& __is, linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x); |
| }; |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type |
| linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier; |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type |
| linear_congruential_engine<_UIntType, __a, __c, __m>::increment; |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type |
| linear_congruential_engine<_UIntType, __a, __c, __m>::modulus; |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type |
| linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed; |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| template <class _Sseq> |
| void linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q, integral_constant<unsigned, 1>) { |
| const unsigned __k = 1; |
| uint32_t __ar[__k + 3]; |
| __q.generate(__ar, __ar + __k + 3); |
| result_type __s = static_cast<result_type>(__ar[3] % __m); |
| __x_ = __c == 0 && __s == 0 ? result_type(1) : __s; |
| } |
| |
| template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| template <class _Sseq> |
| void linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q, integral_constant<unsigned, 2>) { |
| const unsigned __k = 2; |
| uint32_t __ar[__k + 3]; |
| __q.generate(__ar, __ar + __k + 3); |
| result_type __s = static_cast<result_type>((__ar[3] + ((uint64_t)__ar[4] << 32)) % __m); |
| __x_ = __c == 0 && __s == 0 ? result_type(1) : __s; |
| } |
| |
| template <class _CharT, class _Traits, class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& |
| operator<<(basic_ostream<_CharT, _Traits>& __os, const linear_congruential_engine<_UIntType, __a, __c, __m>& __x) { |
| __save_flags<_CharT, _Traits> __lx(__os); |
| typedef basic_ostream<_CharT, _Traits> _Ostream; |
| __os.flags(_Ostream::dec | _Ostream::left); |
| __os.fill(__os.widen(' ')); |
| return __os << __x.__x_; |
| } |
| |
| template <class _CharT, class _Traits, class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& |
| operator>>(basic_istream<_CharT, _Traits>& __is, linear_congruential_engine<_UIntType, __a, __c, __m>& __x) { |
| __save_flags<_CharT, _Traits> __lx(__is); |
| typedef basic_istream<_CharT, _Traits> _Istream; |
| __is.flags(_Istream::dec | _Istream::skipws); |
| _UIntType __t; |
| __is >> __t; |
| if (!__is.fail()) |
| __x.__x_ = __t; |
| return __is; |
| } |
| |
| typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647> minstd_rand0; |
| typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647> minstd_rand; |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___RANDOM_LINEAR_CONGRUENTIAL_ENGINE_H |
