From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libstdc++-v3/include/std/ratio | 393 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 393 insertions(+) create mode 100644 libstdc++-v3/include/std/ratio (limited to 'libstdc++-v3/include/std/ratio') diff --git a/libstdc++-v3/include/std/ratio b/libstdc++-v3/include/std/ratio new file mode 100644 index 000000000..17d28a10f --- /dev/null +++ b/libstdc++-v3/include/std/ratio @@ -0,0 +1,393 @@ +// ratio -*- C++ -*- + +// Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// Under Section 7 of GPL version 3, you are granted additional +// permissions described in the GCC Runtime Library Exception, version +// 3.1, as published by the Free Software Foundation. + +// You should have received a copy of the GNU General Public License and +// a copy of the GCC Runtime Library Exception along with this program; +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +// . + +/** @file include/ratio + * This is a Standard C++ Library header. + */ + +#ifndef _GLIBCXX_RATIO +#define _GLIBCXX_RATIO 1 + +#pragma GCC system_header + +#ifndef __GXX_EXPERIMENTAL_CXX0X__ +# include +#else + +#include +#include + +#ifdef _GLIBCXX_USE_C99_STDINT_TR1 + +namespace std _GLIBCXX_VISIBILITY(default) +{ +_GLIBCXX_BEGIN_NAMESPACE_VERSION + + /** + * @defgroup ratio Rational Arithmetic + * @ingroup utilities + * + * Compile time representation of finite rational numbers. + * @{ + */ + + template + struct __static_sign + : integral_constant + { }; + + template + struct __static_abs + : integral_constant::value> + { }; + + template + struct __static_gcd; + + template + struct __static_gcd + : __static_gcd<_Qn, (_Pn % _Qn)> + { }; + + template + struct __static_gcd<_Pn, 0> + : integral_constant::value> + { }; + + template + struct __static_gcd<0, _Qn> + : integral_constant::value> + { }; + + // Let c = 2^(half # of bits in an intmax_t) + // then we find a1, a0, b1, b0 s.t. N = a1*c + a0, M = b1*c + b0 + // The multiplication of N and M becomes, + // N * M = (a1 * b1)c^2 + (a0 * b1 + b0 * a1)c + a0 * b0 + // Multiplication is safe if each term and the sum of the terms + // is representable by intmax_t. + template + struct __safe_multiply + { + private: + static const uintmax_t __c = uintmax_t(1) << (sizeof(intmax_t) * 4); + + static const uintmax_t __a0 = __static_abs<_Pn>::value % __c; + static const uintmax_t __a1 = __static_abs<_Pn>::value / __c; + static const uintmax_t __b0 = __static_abs<_Qn>::value % __c; + static const uintmax_t __b1 = __static_abs<_Qn>::value / __c; + + static_assert(__a1 == 0 || __b1 == 0, + "overflow in multiplication"); + static_assert(__a0 * __b1 + __b0 * __a1 < (__c >> 1), + "overflow in multiplication"); + static_assert(__b0 * __a0 <= __INTMAX_MAX__, + "overflow in multiplication"); + static_assert((__a0 * __b1 + __b0 * __a1) * __c <= + __INTMAX_MAX__ - __b0 * __a0, "overflow in multiplication"); + + public: + static const intmax_t value = _Pn * _Qn; + }; + + // Helpers for __safe_add + template + struct __add_overflow_check_impl + : integral_constant + { }; + + template + struct __add_overflow_check_impl<_Pn, _Qn, false> + : integral_constant= -__INTMAX_MAX__ - _Qn)> + { }; + + template + struct __add_overflow_check + : __add_overflow_check_impl<_Pn, _Qn, (_Qn >= 0)> + { }; + + template + struct __safe_add + { + static_assert(__add_overflow_check<_Pn, _Qn>::value != 0, + "overflow in addition"); + + static const intmax_t value = _Pn + _Qn; + }; + + /** + * @brief Provides compile-time rational arithmetic. + * + * This class template represents any finite rational number with a + * numerator and denominator representable by compile-time constants of + * type intmax_t. The ratio is simplified when instantiated. + * + * For example: + * @code + * std::ratio<7,-21>::num == -1; + * std::ratio<7,-21>::den == 3; + * @endcode + * + */ + template + struct ratio + { + static_assert(_Den != 0, "denominator cannot be zero"); + static_assert(_Num >= -__INTMAX_MAX__ && _Den >= -__INTMAX_MAX__, + "out of range"); + + // Note: sign(N) * abs(N) == N + static constexpr intmax_t num = + _Num * __static_sign<_Den>::value / __static_gcd<_Num, _Den>::value; + + static constexpr intmax_t den = + __static_abs<_Den>::value / __static_gcd<_Num, _Den>::value; + + typedef ratio type; + }; + + template + constexpr intmax_t ratio<_Num, _Den>::num; + + template + constexpr intmax_t ratio<_Num, _Den>::den; + + /// ratio_add + template + struct ratio_add + { + private: + static constexpr intmax_t __gcd = + __static_gcd<_R1::den, _R2::den>::value; + static constexpr intmax_t __n = __safe_add< + __safe_multiply<_R1::num, (_R2::den / __gcd)>::value, + __safe_multiply<_R2::num, (_R1::den / __gcd)>::value>::value; + + // The new numerator may have common factors with the denominator, + // but they have to also be factors of __gcd. + static constexpr intmax_t __gcd2 = __static_gcd<__n, __gcd>::value; + + public: + typedef ratio<__n / __gcd2, + __safe_multiply<_R1::den / __gcd2, _R2::den / __gcd>::value> type; + + static constexpr intmax_t num = type::num; + static constexpr intmax_t den = type::den; + }; + + template + constexpr intmax_t ratio_add<_R1, _R2>::num; + + template + constexpr intmax_t ratio_add<_R1, _R2>::den; + + /// ratio_subtract + template + struct ratio_subtract + { + typedef typename ratio_add< + _R1, + ratio<-_R2::num, _R2::den>>::type type; + + static constexpr intmax_t num = type::num; + static constexpr intmax_t den = type::den; + }; + + template + constexpr intmax_t ratio_subtract<_R1, _R2>::num; + + template + constexpr intmax_t ratio_subtract<_R1, _R2>::den; + + /// ratio_multiply + template + struct ratio_multiply + { + private: + static const intmax_t __gcd1 = + __static_gcd<_R1::num, _R2::den>::value; + static const intmax_t __gcd2 = + __static_gcd<_R2::num, _R1::den>::value; + + public: + typedef ratio< + __safe_multiply<(_R1::num / __gcd1), + (_R2::num / __gcd2)>::value, + __safe_multiply<(_R1::den / __gcd2), + (_R2::den / __gcd1)>::value> type; + + static constexpr intmax_t num = type::num; + static constexpr intmax_t den = type::den; + }; + + template + constexpr intmax_t ratio_multiply<_R1, _R2>::num; + + template + constexpr intmax_t ratio_multiply<_R1, _R2>::den; + + /// ratio_divide + template + struct ratio_divide + { + static_assert(_R2::num != 0, "division by 0"); + + typedef typename ratio_multiply< + _R1, + ratio<_R2::den, _R2::num>>::type type; + + static constexpr intmax_t num = type::num; + static constexpr intmax_t den = type::den; + }; + + template + constexpr intmax_t ratio_divide<_R1, _R2>::num; + + template + constexpr intmax_t ratio_divide<_R1, _R2>::den; + + /// ratio_equal + template + struct ratio_equal + : integral_constant + { }; + + /// ratio_not_equal + template + struct ratio_not_equal + : integral_constant::value> + { }; + + // 0 <= _Ri < 1 + // If one is 0, conclude + // Otherwise, x < y iff 1/y < 1/x + template + struct __ratio_less_impl_2; + + // _Ri > 0 + // Compare the integral parts, and remove them if they are equal + template + struct __ratio_less_impl_1 + : __ratio_less_impl_2, + ratio<_R2::num % _R2::den, _R2::den> >::type + { }; + + template + struct __ratio_less_impl_1<_R1, _R2, __q1, __q2, false> + : integral_constant + { }; + + template + struct __ratio_less_impl_2 + : __ratio_less_impl_1, + ratio<_R1::den, _R1::num> >::type + { }; + + template + struct __ratio_less_impl_2, _R2> + : integral_constant + { }; + + template + struct __ratio_less_impl_2<_R1, ratio<0, __d2> > + : integral_constant + { }; + + template + struct __ratio_less_impl_2, ratio<0, __d2> > + : integral_constant + { }; + + template::value + != __static_sign<_R2::num>::value)), + bool = (__static_sign<_R1::num>::value == -1 + && __static_sign<_R2::num>::value == -1)> + struct __ratio_less_impl + : __ratio_less_impl_1<_R1, _R2>::type + { }; + + template + struct __ratio_less_impl<_R1, _R2, true, false> + : integral_constant + { }; + + template + struct __ratio_less_impl<_R1, _R2, false, true> + : __ratio_less_impl_1, + ratio<-_R1::num, _R1::den> >::type + { }; + + /// ratio_less + // using a continued fraction expansion + template + struct ratio_less + : __ratio_less_impl<_R1, _R2>::type + { }; + + /// ratio_less_equal + template + struct ratio_less_equal + : integral_constant::value> + { }; + + /// ratio_greater + template + struct ratio_greater + : integral_constant::value> + { }; + + /// ratio_greater_equal + template + struct ratio_greater_equal + : integral_constant::value> + { }; + + typedef ratio<1, 1000000000000000000> atto; + typedef ratio<1, 1000000000000000> femto; + typedef ratio<1, 1000000000000> pico; + typedef ratio<1, 1000000000> nano; + typedef ratio<1, 1000000> micro; + typedef ratio<1, 1000> milli; + typedef ratio<1, 100> centi; + typedef ratio<1, 10> deci; + typedef ratio< 10, 1> deca; + typedef ratio< 100, 1> hecto; + typedef ratio< 1000, 1> kilo; + typedef ratio< 1000000, 1> mega; + typedef ratio< 1000000000, 1> giga; + typedef ratio< 1000000000000, 1> tera; + typedef ratio< 1000000000000000, 1> peta; + typedef ratio< 1000000000000000000, 1> exa; + + // @} group ratio +_GLIBCXX_END_NAMESPACE_VERSION +} // namespace + +#endif //_GLIBCXX_USE_C99_STDINT_TR1 + +#endif //__GXX_EXPERIMENTAL_CXX0X__ + +#endif //_GLIBCXX_RATIO -- cgit v1.2.3