| // (C) Copyright John Maddock 2000. |
| // Use, modification and distribution are subject to 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). |
| // |
| // See http://www.boost.org/libs/type_traits for most recent version including documentation. |
| |
| #ifndef BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED |
| #define BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED |
| |
| #include <boost/type_traits/alignment_of.hpp> |
| #include <boost/type_traits/is_pod.hpp> |
| #include <boost/static_assert.hpp> |
| #include <boost/config.hpp> |
| #include <cstddef> // size_t |
| #include <boost/detail/workaround.hpp> |
| |
| #ifdef BOOST_MSVC |
| # pragma warning(push) |
| # pragma warning(disable: 4121) // alignment is sensitive to packing |
| #endif |
| |
| #ifdef _MSC_VER |
| #include <boost/type_traits/conditional.hpp> |
| #endif |
| |
| namespace boost { |
| namespace detail{ |
| |
| #ifndef __BORLANDC__ |
| |
| union max_align |
| { |
| char c; |
| short s; |
| int i; |
| long l; |
| #ifndef BOOST_NO_LONG_LONG |
| boost::long_long_type ll; |
| #endif |
| #ifdef BOOST_HAS_INT128 |
| boost::int128_type i128; |
| #endif |
| float f; |
| double d; |
| long double ld; |
| #ifdef BOOST_HAS_FLOAT128 |
| __float128 f128; |
| #endif |
| }; |
| |
| template <std::size_t Target, bool check> struct long_double_alignment{ typedef long double type; }; |
| template <std::size_t Target> struct long_double_alignment<Target, false>{ typedef boost::detail::max_align type; }; |
| |
| template <std::size_t Target, bool check> struct double_alignment{ typedef double type; }; |
| template <std::size_t Target> struct double_alignment<Target, false>{ typedef typename long_double_alignment<Target, boost::alignment_of<long double>::value >= Target>::type type; }; |
| |
| #ifndef BOOST_NO_LONG_LONG |
| template <std::size_t Target, bool check> struct long_long_alignment{ typedef boost::long_long_type type; }; |
| template <std::size_t Target> struct long_long_alignment<Target, false>{ typedef typename double_alignment<Target, boost::alignment_of<double>::value >= Target>::type type; }; |
| #endif |
| |
| template <std::size_t Target, bool check> struct long_alignment{ typedef long type; }; |
| #ifndef BOOST_NO_LONG_LONG |
| template <std::size_t Target> struct long_alignment<Target, false>{ typedef typename long_long_alignment<Target, boost::alignment_of<boost::long_long_type>::value >= Target>::type type; }; |
| #else |
| template <std::size_t Target> struct long_alignment<Target, false>{ typedef typename double_alignment<Target, boost::alignment_of<double>::value >= Target>::type type; }; |
| #endif |
| |
| template <std::size_t Target, bool check> struct int_alignment{ typedef int type; }; |
| template <std::size_t Target> struct int_alignment<Target, false>{ typedef typename long_alignment<Target, boost::alignment_of<long>::value >= Target>::type type; }; |
| |
| template <std::size_t Target, bool check> struct short_alignment{ typedef short type; }; |
| template <std::size_t Target> struct short_alignment<Target, false>{ typedef typename int_alignment<Target, boost::alignment_of<int>::value >= Target>::type type; }; |
| |
| template <std::size_t Target, bool check> struct char_alignment{ typedef char type; }; |
| template <std::size_t Target> struct char_alignment<Target, false>{ typedef typename short_alignment<Target, boost::alignment_of<short>::value >= Target>::type type; }; |
| |
| } |
| |
| template <std::size_t Align> |
| struct type_with_alignment |
| { |
| typedef typename boost::detail::char_alignment<Align, boost::alignment_of<char>::value >= Align>::type type; |
| }; |
| |
| #if (defined(__GNUC__) || (defined (__SUNPRO_CC) && (__SUNPRO_CC >= 0x5130)) || defined(__clang__)) && !defined(BOOST_TT_DISABLE_INTRINSICS) |
| namespace tt_align_ns { |
| struct __attribute__((__aligned__(2))) a2 {}; |
| struct __attribute__((__aligned__(4))) a4 {}; |
| struct __attribute__((__aligned__(8))) a8 {}; |
| struct __attribute__((__aligned__(16))) a16 {}; |
| struct __attribute__((__aligned__(32))) a32 {}; |
| struct __attribute__((__aligned__(64))) a64 {}; |
| struct __attribute__((__aligned__(128))) a128 {}; |
| } |
| |
| template<> struct type_with_alignment<1> { public: typedef char type; }; |
| template<> struct type_with_alignment<2> { public: typedef tt_align_ns::a2 type; }; |
| template<> struct type_with_alignment<4> { public: typedef tt_align_ns::a4 type; }; |
| template<> struct type_with_alignment<8> { public: typedef tt_align_ns::a8 type; }; |
| template<> struct type_with_alignment<16> { public: typedef tt_align_ns::a16 type; }; |
| template<> struct type_with_alignment<32> { public: typedef tt_align_ns::a32 type; }; |
| template<> struct type_with_alignment<64> { public: typedef tt_align_ns::a64 type; }; |
| template<> struct type_with_alignment<128> { public: typedef tt_align_ns::a128 type; }; |
| |
| template<> struct is_pod< ::boost::tt_align_ns::a2> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a4> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a8> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a16> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a32> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a64> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a128> : public true_type{}; |
| |
| #endif |
| #if (defined(BOOST_MSVC) || (defined(BOOST_INTEL) && defined(_MSC_VER))) && !defined(BOOST_TT_DISABLE_INTRINSICS) |
| // |
| // MSVC supports types which have alignments greater than the normal |
| // maximum: these are used for example in the types __m64 and __m128 |
| // to provide types with alignment requirements which match the SSE |
| // registers. Therefore we extend type_with_alignment<> to support |
| // such types, however, we have to be careful to use a builtin type |
| // whenever possible otherwise we break previously working code: |
| // see http://article.gmane.org/gmane.comp.lib.boost.devel/173011 |
| // for an example and test case. Thus types like a8 below will |
| // be used *only* if the existing implementation can't provide a type |
| // with suitable alignment. This does mean however, that type_with_alignment<> |
| // may return a type which cannot be passed through a function call |
| // by value (and neither can any type containing such a type like |
| // Boost.Optional). However, this only happens when we have no choice |
| // in the matter because no other "ordinary" type is available. |
| // |
| namespace tt_align_ns { |
| struct __declspec(align(8)) a8 { |
| char m[8]; |
| typedef a8 type; |
| }; |
| struct __declspec(align(16)) a16 { |
| char m[16]; |
| typedef a16 type; |
| }; |
| struct __declspec(align(32)) a32 { |
| char m[32]; |
| typedef a32 type; |
| }; |
| struct __declspec(align(64)) a64 |
| { |
| char m[64]; |
| typedef a64 type; |
| }; |
| struct __declspec(align(128)) a128 { |
| char m[128]; |
| typedef a128 type; |
| }; |
| } |
| |
| template<> struct type_with_alignment<8> |
| { |
| typedef boost::conditional< |
| ::boost::alignment_of<boost::detail::max_align>::value < 8, |
| tt_align_ns::a8, |
| boost::detail::char_alignment<8, false> >::type t1; |
| public: |
| typedef t1::type type; |
| }; |
| template<> struct type_with_alignment<16> |
| { |
| typedef boost::conditional< |
| ::boost::alignment_of<boost::detail::max_align>::value < 16, |
| tt_align_ns::a16, |
| boost::detail::char_alignment<16, false> >::type t1; |
| public: |
| typedef t1::type type; |
| }; |
| template<> struct type_with_alignment<32> |
| { |
| typedef boost::conditional< |
| ::boost::alignment_of<boost::detail::max_align>::value < 32, |
| tt_align_ns::a32, |
| boost::detail::char_alignment<32, false> >::type t1; |
| public: |
| typedef t1::type type; |
| }; |
| template<> struct type_with_alignment<64> { |
| typedef boost::conditional< |
| ::boost::alignment_of<boost::detail::max_align>::value < 64, |
| tt_align_ns::a64, |
| boost::detail::char_alignment<64, false> >::type t1; |
| public: |
| typedef t1::type type; |
| }; |
| template<> struct type_with_alignment<128> { |
| typedef boost::conditional< |
| ::boost::alignment_of<boost::detail::max_align>::value < 128, |
| tt_align_ns::a128, |
| boost::detail::char_alignment<128, false> >::type t1; |
| public: |
| typedef t1::type type; |
| }; |
| |
| template<> struct is_pod< ::boost::tt_align_ns::a8> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a16> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a32> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a64> : public true_type{}; |
| template<> struct is_pod< ::boost::tt_align_ns::a128> : public true_type{}; |
| |
| #endif |
| |
| #else |
| |
| // |
| // Borland specific version, we have this for two reasons: |
| // 1) The version above doesn't always compile (with the new test cases for example) |
| // 2) Because of Borlands #pragma option we can create types with alignments that are |
| // greater that the largest aligned builtin type. |
| |
| namespace tt_align_ns{ |
| #pragma option push -a16 |
| struct a2{ short s; }; |
| struct a4{ int s; }; |
| struct a8{ double s; }; |
| struct a16{ long double s; }; |
| #pragma option pop |
| } |
| |
| namespace detail { |
| |
| typedef ::boost::tt_align_ns::a16 max_align; |
| |
| } |
| //#if ! BOOST_WORKAROUND(__CODEGEARC__, BOOST_TESTED_AT(0x610)) |
| template <> struct is_pod< ::boost::tt_align_ns::a2> : public true_type{}; |
| template <> struct is_pod< ::boost::tt_align_ns::a4> : public true_type{}; |
| template <> struct is_pod< ::boost::tt_align_ns::a8> : public true_type{}; |
| template <> struct is_pod< ::boost::tt_align_ns::a16> : public true_type{}; |
| //#endif |
| |
| template <std::size_t N> struct type_with_alignment |
| { |
| // We should never get to here, but if we do use the maximally |
| // aligned type: |
| // BOOST_STATIC_ASSERT(0); |
| typedef tt_align_ns::a16 type; |
| }; |
| template <> struct type_with_alignment<1>{ typedef char type; }; |
| template <> struct type_with_alignment<2>{ typedef tt_align_ns::a2 type; }; |
| template <> struct type_with_alignment<4>{ typedef tt_align_ns::a4 type; }; |
| template <> struct type_with_alignment<8>{ typedef tt_align_ns::a8 type; }; |
| template <> struct type_with_alignment<16>{ typedef tt_align_ns::a16 type; }; |
| |
| #endif |
| |
| } // namespace boost |
| |
| #ifdef BOOST_MSVC |
| # pragma warning(pop) |
| #endif |
| |
| #endif // BOOST_TT_TYPE_WITH_ALIGNMENT_INCLUDED |
| |
| |