368faacac7
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9, which were related to the original commit). As landed, 5aaefa51 had unintended consequences on some downstream bots and didn't have proper coverage upstream due to a few subtle things. Implementing this is something we should do in libc++, however we'll first need to address a few issues listed in https://reviews.llvm.org/D106124#3349710. Differential Revision: https://reviews.llvm.org/D120683
353 lines
12 KiB
C++
353 lines
12 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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_SUBTRACT_WITH_CARRY_ENGINE_H
|
|
#define _LIBCPP___RANDOM_SUBTRACT_WITH_CARRY_ENGINE_H
|
|
|
|
#include <__algorithm/equal.h>
|
|
#include <__algorithm/min.h>
|
|
#include <__config>
|
|
#include <__random/is_seed_sequence.h>
|
|
#include <__random/linear_congruential_engine.h>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
#include <iosfwd>
|
|
#include <limits>
|
|
#include <type_traits>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_PUSH_MACROS
|
|
#include <__undef_macros>
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine;
|
|
|
|
template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
bool
|
|
operator==(
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
|
|
|
|
template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
bool
|
|
operator!=(
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
|
|
|
|
template <class _CharT, class _Traits,
|
|
class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>& __os,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
|
|
|
|
template <class _CharT, class _Traits,
|
|
class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __is,
|
|
subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine
|
|
{
|
|
public:
|
|
// types
|
|
typedef _UIntType result_type;
|
|
|
|
private:
|
|
result_type __x_[__r];
|
|
result_type __c_;
|
|
size_t __i_;
|
|
|
|
static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
|
|
static_assert( 0 < __w, "subtract_with_carry_engine invalid parameters");
|
|
static_assert(__w <= _Dt, "subtract_with_carry_engine invalid parameters");
|
|
static_assert( 0 < __s, "subtract_with_carry_engine invalid parameters");
|
|
static_assert(__s < __r, "subtract_with_carry_engine invalid parameters");
|
|
public:
|
|
static _LIBCPP_CONSTEXPR const result_type _Min = 0;
|
|
static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
|
|
(result_type(1) << __w) - result_type(1);
|
|
static_assert(_Min < _Max, "subtract_with_carry_engine invalid parameters");
|
|
|
|
// engine characteristics
|
|
static _LIBCPP_CONSTEXPR const size_t word_size = __w;
|
|
static _LIBCPP_CONSTEXPR const size_t short_lag = __s;
|
|
static _LIBCPP_CONSTEXPR const size_t long_lag = __r;
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
|
|
static _LIBCPP_CONSTEXPR const result_type default_seed = 19780503u;
|
|
|
|
// constructors and seeding functions
|
|
#ifndef _LIBCPP_CXX03_LANG
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
subtract_with_carry_engine() : subtract_with_carry_engine(default_seed) {}
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
explicit subtract_with_carry_engine(result_type __sd) { seed(__sd); }
|
|
#else
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
explicit subtract_with_carry_engine(result_type __sd = default_seed) {
|
|
seed(__sd);
|
|
}
|
|
#endif
|
|
template<class _Sseq>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
explicit subtract_with_carry_engine(_Sseq& __q,
|
|
typename enable_if<__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value>::type* = 0)
|
|
{seed(__q);}
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
void seed(result_type __sd = default_seed)
|
|
{seed(__sd, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
|
|
template<class _Sseq>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
typename enable_if
|
|
<
|
|
__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value,
|
|
void
|
|
>::type
|
|
seed(_Sseq& __q)
|
|
{__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
|
|
|
|
// generating functions
|
|
result_type operator()();
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
|
|
|
|
template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
friend
|
|
bool
|
|
operator==(
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
|
|
|
|
template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
friend
|
|
bool
|
|
operator!=(
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
|
|
|
|
template <class _CharT, class _Traits,
|
|
class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
friend
|
|
basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>& __os,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
|
|
|
|
template <class _CharT, class _Traits,
|
|
class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
friend
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __is,
|
|
subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
|
|
|
|
private:
|
|
|
|
void seed(result_type __sd, integral_constant<unsigned, 1>);
|
|
void seed(result_type __sd, integral_constant<unsigned, 2>);
|
|
template<class _Sseq>
|
|
void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
|
|
template<class _Sseq>
|
|
void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
|
|
};
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
_LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
_LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
_LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
_LIBCPP_CONSTEXPR const typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::result_type
|
|
subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
void
|
|
subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
|
|
integral_constant<unsigned, 1>)
|
|
{
|
|
linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
|
|
__e(__sd == 0u ? default_seed : __sd);
|
|
for (size_t __i = 0; __i < __r; ++__i)
|
|
__x_[__i] = static_cast<result_type>(__e() & _Max);
|
|
__c_ = __x_[__r-1] == 0;
|
|
__i_ = 0;
|
|
}
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
void
|
|
subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
|
|
integral_constant<unsigned, 2>)
|
|
{
|
|
linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
|
|
__e(__sd == 0u ? default_seed : __sd);
|
|
for (size_t __i = 0; __i < __r; ++__i)
|
|
{
|
|
result_type __e0 = __e();
|
|
__x_[__i] = static_cast<result_type>(
|
|
(__e0 + ((uint64_t)__e() << 32)) & _Max);
|
|
}
|
|
__c_ = __x_[__r-1] == 0;
|
|
__i_ = 0;
|
|
}
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
template<class _Sseq>
|
|
void
|
|
subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
|
|
integral_constant<unsigned, 1>)
|
|
{
|
|
const unsigned __k = 1;
|
|
uint32_t __ar[__r * __k];
|
|
__q.generate(__ar, __ar + __r * __k);
|
|
for (size_t __i = 0; __i < __r; ++__i)
|
|
__x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
|
|
__c_ = __x_[__r-1] == 0;
|
|
__i_ = 0;
|
|
}
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
template<class _Sseq>
|
|
void
|
|
subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
|
|
integral_constant<unsigned, 2>)
|
|
{
|
|
const unsigned __k = 2;
|
|
uint32_t __ar[__r * __k];
|
|
__q.generate(__ar, __ar + __r * __k);
|
|
for (size_t __i = 0; __i < __r; ++__i)
|
|
__x_[__i] = static_cast<result_type>(
|
|
(__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
|
|
__c_ = __x_[__r-1] == 0;
|
|
__i_ = 0;
|
|
}
|
|
|
|
template<class _UIntType, size_t __w, size_t __s, size_t __r>
|
|
_UIntType
|
|
subtract_with_carry_engine<_UIntType, __w, __s, __r>::operator()()
|
|
{
|
|
const result_type& __xs = __x_[(__i_ + (__r - __s)) % __r];
|
|
result_type& __xr = __x_[__i_];
|
|
result_type __new_c = __c_ == 0 ? __xs < __xr : __xs != 0 ? __xs <= __xr : 1;
|
|
__xr = (__xs - __xr - __c_) & _Max;
|
|
__c_ = __new_c;
|
|
__i_ = (__i_ + 1) % __r;
|
|
return __xr;
|
|
}
|
|
|
|
template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
bool
|
|
operator==(
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
|
|
{
|
|
if (__x.__c_ != __y.__c_)
|
|
return false;
|
|
if (__x.__i_ == __y.__i_)
|
|
return _VSTD::equal(__x.__x_, __x.__x_ + _Rp, __y.__x_);
|
|
if (__x.__i_ == 0 || __y.__i_ == 0)
|
|
{
|
|
size_t __j = _VSTD::min(_Rp - __x.__i_, _Rp - __y.__i_);
|
|
if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
|
|
__y.__x_ + __y.__i_))
|
|
return false;
|
|
if (__x.__i_ == 0)
|
|
return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Rp, __y.__x_);
|
|
return _VSTD::equal(__x.__x_, __x.__x_ + (_Rp - __j), __y.__x_ + __j);
|
|
}
|
|
if (__x.__i_ < __y.__i_)
|
|
{
|
|
size_t __j = _Rp - __y.__i_;
|
|
if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
|
|
__y.__x_ + __y.__i_))
|
|
return false;
|
|
if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Rp,
|
|
__y.__x_))
|
|
return false;
|
|
return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
|
|
__y.__x_ + (_Rp - (__x.__i_ + __j)));
|
|
}
|
|
size_t __j = _Rp - __x.__i_;
|
|
if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
|
|
__x.__x_ + __x.__i_))
|
|
return false;
|
|
if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Rp,
|
|
__x.__x_))
|
|
return false;
|
|
return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
|
|
__x.__x_ + (_Rp - (__y.__i_ + __j)));
|
|
}
|
|
|
|
template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
bool
|
|
operator!=(
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
|
|
{
|
|
return !(__x == __y);
|
|
}
|
|
|
|
template <class _CharT, class _Traits,
|
|
class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>& __os,
|
|
const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
|
|
{
|
|
__save_flags<_CharT, _Traits> __lx(__os);
|
|
typedef basic_ostream<_CharT, _Traits> _Ostream;
|
|
__os.flags(_Ostream::dec | _Ostream::left);
|
|
_CharT __sp = __os.widen(' ');
|
|
__os.fill(__sp);
|
|
__os << __x.__x_[__x.__i_];
|
|
for (size_t __j = __x.__i_ + 1; __j < _Rp; ++__j)
|
|
__os << __sp << __x.__x_[__j];
|
|
for (size_t __j = 0; __j < __x.__i_; ++__j)
|
|
__os << __sp << __x.__x_[__j];
|
|
__os << __sp << __x.__c_;
|
|
return __os;
|
|
}
|
|
|
|
template <class _CharT, class _Traits,
|
|
class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __is,
|
|
subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
|
|
{
|
|
__save_flags<_CharT, _Traits> __lx(__is);
|
|
typedef basic_istream<_CharT, _Traits> _Istream;
|
|
__is.flags(_Istream::dec | _Istream::skipws);
|
|
_UInt __t[_Rp+1];
|
|
for (size_t __i = 0; __i < _Rp+1; ++__i)
|
|
__is >> __t[__i];
|
|
if (!__is.fail())
|
|
{
|
|
for (size_t __i = 0; __i < _Rp; ++__i)
|
|
__x.__x_[__i] = __t[__i];
|
|
__x.__c_ = __t[_Rp];
|
|
__x.__i_ = 0;
|
|
}
|
|
return __is;
|
|
}
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
_LIBCPP_POP_MACROS
|
|
|
|
#endif // _LIBCPP___RANDOM_SUBTRACT_WITH_CARRY_ENGINE_H
|