Mercurial > hg > vamp-build-and-test
diff DEPENDENCIES/generic/include/boost/multiprecision/detail/generic_interconvert.hpp @ 16:2665513ce2d3
Add boost headers
author | Chris Cannam |
---|---|
date | Tue, 05 Aug 2014 11:11:38 +0100 |
parents | |
children | c530137014c0 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DEPENDENCIES/generic/include/boost/multiprecision/detail/generic_interconvert.hpp Tue Aug 05 11:11:38 2014 +0100 @@ -0,0 +1,228 @@ +/////////////////////////////////////////////////////////////////////////////// +// Copyright 2011 John Maddock. Distributed under the Boost +// Software License, Version 1.0. (See accompanying file +// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +#ifndef BOOST_MP_GENERIC_INTERCONVERT_HPP +#define BOOST_MP_GENERIC_INTERCONVERT_HPP + +#include <boost/multiprecision/detail/default_ops.hpp> + +namespace boost{ namespace multiprecision{ namespace detail{ + +template <class To, class From> +void generic_interconvert(To& to, const From& from, const mpl::int_<number_kind_floating_point>& /*to_type*/, const mpl::int_<number_kind_integer>& /*from_type*/) +{ + using default_ops::eval_get_sign; + using default_ops::eval_bitwise_and; + using default_ops::eval_convert_to; + using default_ops::eval_right_shift; + using default_ops::eval_ldexp; + using default_ops::eval_add; + // smallest unsigned type handled natively by "From" is likely to be it's limb_type: + typedef typename canonical<unsigned char, From>::type limb_type; + // get the corresponding type that we can assign to "To": + typedef typename canonical<limb_type, To>::type to_type; + From t(from); + bool is_neg = eval_get_sign(t) < 0; + if(is_neg) + t.negate(); + // Pick off the first limb: + limb_type limb; + limb_type mask = ~static_cast<limb_type>(0); + From fl; + eval_bitwise_and(fl, t, mask); + eval_convert_to(&limb, fl); + to = static_cast<to_type>(limb); + eval_right_shift(t, std::numeric_limits<limb_type>::digits); + // + // Then keep picking off more limbs until "t" is zero: + // + To l; + unsigned shift = std::numeric_limits<limb_type>::digits; + while(!eval_is_zero(t)) + { + eval_bitwise_and(fl, t, mask); + eval_convert_to(&limb, fl); + l = static_cast<to_type>(limb); + eval_right_shift(t, std::numeric_limits<limb_type>::digits); + eval_ldexp(l, l, shift); + eval_add(to, l); + shift += std::numeric_limits<limb_type>::digits; + } + // + // Finish off by setting the sign: + // + if(is_neg) + to.negate(); +} + +template <class To, class From> +void generic_interconvert(To& to, const From& from, const mpl::int_<number_kind_integer>& /*to_type*/, const mpl::int_<number_kind_integer>& /*from_type*/) +{ + using default_ops::eval_get_sign; + using default_ops::eval_bitwise_and; + using default_ops::eval_convert_to; + using default_ops::eval_right_shift; + using default_ops::eval_left_shift; + using default_ops::eval_bitwise_or; + using default_ops::eval_is_zero; + // smallest unsigned type handled natively by "From" is likely to be it's limb_type: + typedef typename canonical<unsigned char, From>::type limb_type; + // get the corresponding type that we can assign to "To": + typedef typename canonical<limb_type, To>::type to_type; + From t(from); + bool is_neg = eval_get_sign(t) < 0; + if(is_neg) + t.negate(); + // Pick off the first limb: + limb_type limb; + limb_type mask = static_cast<limb_type>(~static_cast<limb_type>(0)); + From fl; + eval_bitwise_and(fl, t, mask); + eval_convert_to(&limb, fl); + to = static_cast<to_type>(limb); + eval_right_shift(t, std::numeric_limits<limb_type>::digits); + // + // Then keep picking off more limbs until "t" is zero: + // + To l; + unsigned shift = std::numeric_limits<limb_type>::digits; + while(!eval_is_zero(t)) + { + eval_bitwise_and(fl, t, mask); + eval_convert_to(&limb, fl); + l = static_cast<to_type>(limb); + eval_right_shift(t, std::numeric_limits<limb_type>::digits); + eval_left_shift(l, shift); + eval_bitwise_or(to, l); + shift += std::numeric_limits<limb_type>::digits; + } + // + // Finish off by setting the sign: + // + if(is_neg) + to.negate(); +} + +template <class To, class From> +void generic_interconvert(To& to, const From& from, const mpl::int_<number_kind_floating_point>& /*to_type*/, const mpl::int_<number_kind_floating_point>& /*from_type*/) +{ +#ifdef BOOST_MSVC +#pragma warning(push) +#pragma warning(disable:4127) +#endif + // + // The code here only works when the radix of "From" is 2, we could try shifting by other + // radixes but it would complicate things.... use a string conversion when the radix is other + // than 2: + // + if(std::numeric_limits<number<From> >::radix != 2) + { + to = from.str(0, std::ios_base::fmtflags()).c_str(); + return; + } + + + typedef typename canonical<unsigned char, To>::type ui_type; + + using default_ops::eval_fpclassify; + using default_ops::eval_add; + using default_ops::eval_subtract; + using default_ops::eval_convert_to; + + // + // First classify the input, then handle the special cases: + // + int c = eval_fpclassify(from); + + if(c == FP_ZERO) + { + to = ui_type(0); + return; + } + else if(c == FP_NAN) + { + to = "nan"; + return; + } + else if(c == FP_INFINITE) + { + to = "inf"; + if(eval_get_sign(from) < 0) + to.negate(); + return; + } + + typename From::exponent_type e; + From f, term; + to = ui_type(0); + + eval_frexp(f, from, &e); + + static const int shift = std::numeric_limits<boost::intmax_t>::digits - 1; + + while(!eval_is_zero(f)) + { + // extract int sized bits from f: + eval_ldexp(f, f, shift); + eval_floor(term, f); + e -= shift; + eval_ldexp(to, to, shift); + typename boost::multiprecision::detail::canonical<boost::intmax_t, To>::type ll; + eval_convert_to(&ll, term); + eval_add(to, ll); + eval_subtract(f, term); + } + typedef typename To::exponent_type to_exponent; + if((e > (std::numeric_limits<to_exponent>::max)()) || (e < (std::numeric_limits<to_exponent>::min)())) + { + to = "inf"; + if(eval_get_sign(from) < 0) + to.negate(); + return; + } + eval_ldexp(to, to, static_cast<to_exponent>(e)); +#ifdef BOOST_MSVC +#pragma warning(pop) +#endif +} + +template <class To, class From> +void generic_interconvert(To& to, const From& from, const mpl::int_<number_kind_rational>& /*to_type*/, const mpl::int_<number_kind_rational>& /*from_type*/) +{ + typedef typename component_type<number<To> >::type to_component_type; + + number<From> t(from); + to_component_type n(numerator(t)), d(denominator(t)); + using default_ops::assign_components; + assign_components(to, n.backend(), d.backend()); +} + +template <class To, class From> +void generic_interconvert(To& to, const From& from, const mpl::int_<number_kind_rational>& /*to_type*/, const mpl::int_<number_kind_integer>& /*from_type*/) +{ + typedef typename component_type<number<To> >::type to_component_type; + + number<From> t(from); + to_component_type n(t), d(1); + using default_ops::assign_components; + assign_components(to, n.backend(), d.backend()); +} + +template <class To, class From> +void generic_interconvert(To& to, const From& from, const mpl::int_<number_kind_floating_point>& /*to_type*/, const mpl::int_<number_kind_rational>& /*from_type*/) +{ + typedef typename component_type<number<From> >::type from_component_type; + using default_ops::eval_divide; + + number<From> t(from); + from_component_type n(numerator(t)), d(denominator(t)); + number<To> fn(n), fd(d); + eval_divide(to, fn.backend(), fd.backend()); +} + +}}} // namespaces + +#endif // BOOST_MP_GENERIC_INTERCONVERT_HPP +