--- /dev/null
+// ratio -*- C++ -*-
+
+// Copyright (C) 2008, 2009 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
+// <http://www.gnu.org/licenses/>.
+
+/** @file ratio
+ * This is a Standard C++ Library header.
+ */
+
+#ifndef _GLIBCXX_RATIO
+#define _GLIBCXX_RATIO 1
+
+#pragma GCC system_header
+
+#ifndef __GXX_EXPERIMENTAL_CXX0X__
+# include <c++0x_warning.h>
+#else
+
+#include <type_traits>
+#include <cstdint>
+
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+
+namespace std
+{
+ /**
+ * @defgroup ratio Rational Arithmetic
+ * @ingroup utilities
+ *
+ * Compile time representation of fininte rational numbers.
+ * @{
+ */
+
+ template<intmax_t _Pn>
+ struct __static_sign
+ : integral_constant<intmax_t, (_Pn < 0) ? -1 : 1>
+ { };
+
+ template<intmax_t _Pn>
+ struct __static_abs
+ : integral_constant<intmax_t, _Pn * __static_sign<_Pn>::value>
+ { };
+
+ template<intmax_t _Pn, intmax_t _Qn>
+ struct __static_gcd;
+
+ template<intmax_t _Pn, intmax_t _Qn>
+ struct __static_gcd
+ : __static_gcd<_Qn, (_Pn % _Qn)>
+ { };
+
+ template<intmax_t _Pn>
+ struct __static_gcd<_Pn, 0>
+ : integral_constant<intmax_t, __static_abs<_Pn>::value>
+ { };
+
+ template<intmax_t _Qn>
+ struct __static_gcd<0, _Qn>
+ : integral_constant<intmax_t, __static_abs<_Qn>::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<intmax_t _Pn, intmax_t _Qn>
+ 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<intmax_t _Pn, intmax_t _Qn, bool>
+ struct __add_overflow_check_impl
+ : integral_constant<bool, (_Pn <= __INTMAX_MAX__ - _Qn)>
+ { };
+
+ template<intmax_t _Pn, intmax_t _Qn>
+ struct __add_overflow_check_impl<_Pn, _Qn, false>
+ : integral_constant<bool, (_Pn >= -__INTMAX_MAX__ - _Qn)>
+ { };
+
+ template<intmax_t _Pn, intmax_t _Qn>
+ struct __add_overflow_check
+ : __add_overflow_check_impl<_Pn, _Qn, (_Qn >= 0)>
+ { };
+
+ template<intmax_t _Pn, intmax_t _Qn>
+ 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<intmax_t _Num, intmax_t _Den = 1>
+ 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 const intmax_t num =
+ _Num * __static_sign<_Den>::value / __static_gcd<_Num, _Den>::value;
+
+ static const intmax_t den =
+ __static_abs<_Den>::value / __static_gcd<_Num, _Den>::value;
+ };
+
+ template<intmax_t _Num, intmax_t _Den>
+ const intmax_t ratio<_Num, _Den>::num;
+
+ template<intmax_t _Num, intmax_t _Den>
+ const intmax_t ratio<_Num, _Den>::den;
+
+ /// ratio_add
+ template<typename _R1, typename _R2>
+ struct ratio_add
+ {
+ private:
+ static const intmax_t __gcd =
+ __static_gcd<_R1::den, _R2::den>::value;
+
+ public:
+ typedef ratio<
+ __safe_add<
+ __safe_multiply<_R1::num, (_R2::den / __gcd)>::value,
+ __safe_multiply<_R2::num, (_R1::den / __gcd)>::value>::value,
+ __safe_multiply<_R1::den, (_R2::den / __gcd)>::value> type;
+ };
+
+ /// ratio_subtract
+ template<typename _R1, typename _R2>
+ struct ratio_subtract
+ {
+ typedef typename ratio_add<
+ _R1,
+ ratio<-_R2::num, _R2::den>>::type type;
+ };
+
+ /// ratio_multiply
+ template<typename _R1, typename _R2>
+ 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;
+ };
+
+ /// ratio_divide
+ template<typename _R1, typename _R2>
+ struct ratio_divide
+ {
+ static_assert(_R2::num != 0, "division by 0");
+
+ typedef typename ratio_multiply<
+ _R1,
+ ratio<_R2::den, _R2::num>>::type type;
+ };
+
+ /// ratio_equal
+ template<typename _R1, typename _R2>
+ struct ratio_equal
+ : integral_constant<bool, _R1::num == _R2::num && _R1::den == _R2::den>
+ { };
+
+ /// ratio_not_equal
+ template<typename _R1, typename _R2>
+ struct ratio_not_equal
+ : integral_constant<bool, !ratio_equal<_R1, _R2>::value>
+ { };
+
+ template<typename _R1, typename _R2>
+ struct __ratio_less_simple_impl
+ : integral_constant<bool,
+ (__safe_multiply<_R1::num, _R2::den>::value
+ < __safe_multiply<_R2::num, _R1::den>::value)>
+ { };
+
+ // If the denominators are equal or the signs differ, we can just compare
+ // numerators, otherwise fallback to the simple cross-multiply method.
+ template<typename _R1, typename _R2>
+ struct __ratio_less_impl
+ : conditional<(_R1::den == _R2::den
+ || (__static_sign<_R1::num>::value
+ != __static_sign<_R2::num>::value)),
+ integral_constant<bool, (_R1::num < _R2::num)>,
+ __ratio_less_simple_impl<_R1, _R2>>::type
+ { };
+
+ /// ratio_less
+ template<typename _R1, typename _R2>
+ struct ratio_less
+ : __ratio_less_impl<_R1, _R2>::type
+ { };
+
+ /// ratio_less_equal
+ template<typename _R1, typename _R2>
+ struct ratio_less_equal
+ : integral_constant<bool, !ratio_less<_R2, _R1>::value>
+ { };
+
+ /// ratio_greater
+ template<typename _R1, typename _R2>
+ struct ratio_greater
+ : integral_constant<bool, ratio_less<_R2, _R1>::value>
+ { };
+
+ /// ratio_greater_equal
+ template<typename _R1, typename _R2>
+ struct ratio_greater_equal
+ : integral_constant<bool, !ratio_less<_R1, _R2>::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
+}
+
+#endif //_GLIBCXX_USE_C99_STDINT_TR1
+
+#endif //__GXX_EXPERIMENTAL_CXX0X__
+
+#endif //_GLIBCXX_RATIO
projects / msp430-gcc.git / blobdiff