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//===- Endian.h - Utilities for IO with endian specific data ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares generic functions to read and write endian specific data.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_ENDIAN_H
#define LLVM_SUPPORT_ENDIAN_H
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/SwapByteOrder.h"
#include "llvm/Support/type_traits.h"
namespace llvm { namespace support { enum endianness {big, little, native};
// These are named values for common alignments.
enum {aligned = 0, unaligned = 1};
namespace detail { /// \brief ::value is either alignment, or alignof(T) if alignment is 0.
template<class T, int alignment> struct PickAlignment { enum {value = alignment == 0 ? AlignOf<T>::Alignment : alignment}; }; } // end namespace detail
namespace endian { template<typename value_type, endianness endian> inline value_type byte_swap(value_type value) { if (endian != native && sys::IsBigEndianHost != (endian == big)) return sys::SwapByteOrder(value); return value; }
template<typename value_type, endianness endian, std::size_t alignment> inline value_type read(const void *memory) { value_type ret;
memcpy(&ret, LLVM_ASSUME_ALIGNED(memory, (detail::PickAlignment<value_type, alignment>::value)), sizeof(value_type)); return byte_swap<value_type, endian>(ret); }
template<typename value_type, endianness endian, std::size_t alignment> inline void write(void *memory, value_type value) { value = byte_swap<value_type, endian>(value); memcpy(LLVM_ASSUME_ALIGNED(memory, (detail::PickAlignment<value_type, alignment>::value)), &value, sizeof(value_type)); } } // end namespace endian
namespace detail { template<typename value_type, endianness endian, std::size_t alignment> struct packed_endian_specific_integral { operator value_type() const { return endian::read<value_type, endian, alignment>( (const void*)Value.buffer); }
void operator=(value_type newValue) { endian::write<value_type, endian, alignment>( (void*)Value.buffer, newValue); }
private: AlignedCharArray<PickAlignment<value_type, alignment>::value, sizeof(value_type)> Value; }; } // end namespace detail
typedef detail::packed_endian_specific_integral <uint8_t, little, unaligned> ulittle8_t; typedef detail::packed_endian_specific_integral <uint16_t, little, unaligned> ulittle16_t; typedef detail::packed_endian_specific_integral <uint32_t, little, unaligned> ulittle32_t; typedef detail::packed_endian_specific_integral <uint64_t, little, unaligned> ulittle64_t;
typedef detail::packed_endian_specific_integral <int8_t, little, unaligned> little8_t; typedef detail::packed_endian_specific_integral <int16_t, little, unaligned> little16_t; typedef detail::packed_endian_specific_integral <int32_t, little, unaligned> little32_t; typedef detail::packed_endian_specific_integral <int64_t, little, unaligned> little64_t;
typedef detail::packed_endian_specific_integral <uint8_t, little, aligned> aligned_ulittle8_t; typedef detail::packed_endian_specific_integral <uint16_t, little, aligned> aligned_ulittle16_t; typedef detail::packed_endian_specific_integral <uint32_t, little, aligned> aligned_ulittle32_t; typedef detail::packed_endian_specific_integral <uint64_t, little, aligned> aligned_ulittle64_t;
typedef detail::packed_endian_specific_integral <int8_t, little, aligned> aligned_little8_t; typedef detail::packed_endian_specific_integral <int16_t, little, aligned> aligned_little16_t; typedef detail::packed_endian_specific_integral <int32_t, little, aligned> aligned_little32_t; typedef detail::packed_endian_specific_integral <int64_t, little, aligned> aligned_little64_t;
typedef detail::packed_endian_specific_integral <uint8_t, big, unaligned> ubig8_t; typedef detail::packed_endian_specific_integral <uint16_t, big, unaligned> ubig16_t; typedef detail::packed_endian_specific_integral <uint32_t, big, unaligned> ubig32_t; typedef detail::packed_endian_specific_integral <uint64_t, big, unaligned> ubig64_t;
typedef detail::packed_endian_specific_integral <int8_t, big, unaligned> big8_t; typedef detail::packed_endian_specific_integral <int16_t, big, unaligned> big16_t; typedef detail::packed_endian_specific_integral <int32_t, big, unaligned> big32_t; typedef detail::packed_endian_specific_integral <int64_t, big, unaligned> big64_t;
typedef detail::packed_endian_specific_integral <uint8_t, big, aligned> aligned_ubig8_t; typedef detail::packed_endian_specific_integral <uint16_t, big, aligned> aligned_ubig16_t; typedef detail::packed_endian_specific_integral <uint32_t, big, aligned> aligned_ubig32_t; typedef detail::packed_endian_specific_integral <uint64_t, big, aligned> aligned_ubig64_t;
typedef detail::packed_endian_specific_integral <int8_t, big, aligned> aligned_big8_t; typedef detail::packed_endian_specific_integral <int16_t, big, aligned> aligned_big16_t; typedef detail::packed_endian_specific_integral <int32_t, big, aligned> aligned_big32_t; typedef detail::packed_endian_specific_integral <int64_t, big, aligned> aligned_big64_t;
typedef detail::packed_endian_specific_integral <uint16_t, native, unaligned> unaligned_uint16_t; typedef detail::packed_endian_specific_integral <uint32_t, native, unaligned> unaligned_uint32_t; typedef detail::packed_endian_specific_integral <uint64_t, native, unaligned> unaligned_uint64_t;
typedef detail::packed_endian_specific_integral <int16_t, native, unaligned> unaligned_int16_t; typedef detail::packed_endian_specific_integral <int32_t, native, unaligned> unaligned_int32_t; typedef detail::packed_endian_specific_integral <int64_t, native, unaligned> unaligned_int64_t; } // end namespace llvm
} // end namespace support
#endif
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