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scummvm/common/endian.h
Hubert Maier 6633c32acb
Update endian.h 
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2022-10-27 15:56:04 +02:00

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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef COMMON_ENDIAN_H
#define COMMON_ENDIAN_H
#include "common/scummsys.h"
/**
* @defgroup common_endian Endian conversions
* @ingroup common
*
* @brief Functions and macros for endian conversions and byteswap conversions.
*
* @details
* - SWAP_BYTES_??(a) - Reverse byte order
* - SWAP_CONSTANT_??(a) - Reverse byte order, implemented as a macro.
* Use with compile-time constants only, the result will be a compile-time constant as well.
* Unlike most other functions, these can be used for e.g. switch-case labels.
* - READ_UINT??(a) - Read native value from pointer @p a.
* - READ_??_UINT??(a) - Read LE/BE value from pointer @p a and convert it to native.
* - WRITE_??_UINT??(a, v) - Write a native value @p v to pointer @p a with LE/BE encoding.
* - TO_??_??(a) - Convert native value @p v to LE/BE.
* - FROM_??_??(a) - Convert LE/BE value @p v to native.
* - CONSTANT_??_??(a) - Convert LE/BE value @p v to native, implemented as a macro.
* Use with compile-time constants only, the result will be a compile-time constant as well.
* Unlike most other functions these, can be used for e.g. switch-case labels.
*
* @{
*/
// Sanity check
#if !defined(SCUMM_LITTLE_ENDIAN) && !defined(SCUMM_BIG_ENDIAN)
# error No endianness defined
#endif
/**
* Swap the bytes in a 64-bit word in order to convert LE encoded data to BE
* and vice versa. Use with compile-time constants only.
*/
#define SWAP_CONSTANT_64(a) \
((uint64)((((a) >> 56) & 0x000000FF) | \
(((a) >> 40) & 0x0000FF00) | \
(((a) >> 24) & 0x00FF0000) | \
(((a) >> 8) & 0xFF000000) | \
(((a) & 0xFF000000) << 8) | \
(((a) & 0x00FF0000) << 24) | \
(((a) & 0x0000FF00) << 40) | \
(((a) & 0x000000FF) << 56) ))
/**
* Swap the bytes in a 32-bit word in order to convert LE encoded data to BE
* and vice versa. Use with compile-time constants only.
*/
#define SWAP_CONSTANT_32(a) \
((uint32)((((a) >> 24) & 0x00FF) | \
(((a) >> 8) & 0xFF00) | \
(((a) & 0xFF00) << 8) | \
(((a) & 0x00FF) << 24) ))
/**
* Swap the bytes in a 16-bit word in order to convert LE encoded data to BE
* and vice versa. Use with compile-time constants only.
*/
#define SWAP_CONSTANT_16(a) \
((uint16)((((a) >> 8) & 0x00FF) | \
(((a) << 8) & 0xFF00) ))
/**
* Swap the bytes in a 16-bit word in order to convert LE encoded data to BE
* and vice versa.
*/
// compiler-specific variants come first, fallback last
#if GCC_ATLEAST(4, 8) || defined(__clang__)
FORCEINLINE uint16 SWAP_BYTES_16(uint16 a) {
return __builtin_bswap16(a);
}
#elif defined(_MSC_VER)
FORCEINLINE uint16 SWAP_BYTES_16(uint16 a) {
return _byteswap_ushort(a);
}
#else
inline uint16 SWAP_BYTES_16(const uint16 a) {
return (a >> 8) | (a << 8);
}
#endif
/**
* Swap the bytes in a 32-bit word in order to convert LE encoded data to BE
* and vice versa.
*/
// compiler-specific variants come first, fallback last
#if defined(__GNUC__)
FORCEINLINE uint32 SWAP_BYTES_32(uint32 a) {
return __builtin_bswap32(a);
}
#elif defined(_MSC_VER)
FORCEINLINE uint32 SWAP_BYTES_32(uint32 a) {
return _byteswap_ulong(a);
}
// generic fallback
#else
inline uint32 SWAP_BYTES_32(uint32 a) {
const uint16 low = (uint16)a, high = (uint16)(a >> 16);
return ((uint32)(uint16)((low >> 8) | (low << 8)) << 16)
| (uint16)((high >> 8) | (high << 8));
}
#endif
/**
* Swap the bytes in a 64-bit word in order to convert LE encoded data to BE
* and vice versa.
*/
// compiler-specific variants come first, fallback last
#if defined(__GNUC__)
FORCEINLINE uint64 SWAP_BYTES_64(uint64 a) {
return __builtin_bswap64(a);
}
#elif defined(_MSC_VER)
FORCEINLINE uint64 SWAP_BYTES_64(uint64 a) {
return _byteswap_uint64(a);
}
// generic fallback
#else
inline uint64 SWAP_BYTES_64(uint64 a) {
uint32 low = (uint32)a, high = (uint32)(a >> 32);
uint16 lowLow = (uint16)low, lowHigh = (uint16)(low >> 16),
highLow = (uint16)high, highHigh = (uint16)(high >> 16);
return ((uint64)(((uint32)(uint16)((lowLow >> 8) | (lowLow << 8)) << 16) |
(uint16)((lowHigh >> 8) | (lowHigh << 8))) << 32) |
(((uint32)(uint16)((highLow >> 8) | (highLow << 8)) << 16) |
(uint16)((highHigh >> 8) | (highHigh << 8)));
}
#endif
/**
* A wrapper macro used around four character constants, like 'DATA', to
* ensure portability. Typical usage: MKTAG('D','A','T','A').
*
* This is required because the C/C++ standard does not define the endianess to
* be used for character constants. Hence, if one uses multi-byte character
* constants, a potential portability problem opens up.
*/
#define MKTAG(a0,a1,a2,a3) ((uint32)((a3) | ((a2) << 8) | ((a1) << 16) | ((a0) << 24)))
/**
* A wrapper macro used around two character constants, like 'wb', to
* ensure portability. Typical usage: MKTAG16('w','b').
*/
#define MKTAG16(a0,a1) ((uint16)((a1) | ((a0) << 8)))
/** @name Functions for reading and writing native integers
* @brief Functions for reading and writing native integer values.
* They also transparently handle the need for alignment.
* @{
*/
// Test for GCC and compatible. These implementations will automatically use
// CPU-specific instructions for unaligned data when they are available (eg.
// MIPS).
#if defined(__GNUC__)
FORCEINLINE uint16 READ_UINT16(const void *ptr) {
struct Unaligned16 { uint16 val; } __attribute__ ((__packed__, __may_alias__));
return ((const Unaligned16 *)ptr)->val;
}
FORCEINLINE uint32 READ_UINT32(const void *ptr) {
struct Unaligned32 { uint32 val; } __attribute__ ((__packed__, __may_alias__));
return ((const Unaligned32 *)ptr)->val;
}
FORCEINLINE void WRITE_UINT16(void *ptr, uint16 value) {
struct Unaligned16 { uint16 val; } __attribute__ ((__packed__, __may_alias__));
((Unaligned16 *)ptr)->val = value;
}
FORCEINLINE void WRITE_UINT32(void *ptr, uint32 value) {
struct Unaligned32 { uint32 val; } __attribute__ ((__packed__, __may_alias__));
((Unaligned32 *)ptr)->val = value;
}
FORCEINLINE uint64 READ_UINT64(const void *ptr) {
struct Unaligned64 { uint64 val; } __attribute__ ((__packed__, __may_alias__));
return ((const Unaligned64 *)ptr)->val;
}
FORCEINLINE void WRITE_UINT64(void *ptr, uint64 value) {
struct Unaligned64 { uint64 val; } __attribute__((__packed__, __may_alias__));
((Unaligned64 *)ptr)->val = value;
}
#elif !defined(SCUMM_NEED_ALIGNMENT)
FORCEINLINE uint16 READ_UINT16(const void *ptr) {
return *(const uint16 *)(ptr);
}
FORCEINLINE uint32 READ_UINT32(const void *ptr) {
return *(const uint32 *)(ptr);
}
FORCEINLINE void WRITE_UINT16(void *ptr, uint16 value) {
*(uint16 *)(ptr) = value;
}
FORCEINLINE void WRITE_UINT32(void *ptr, uint32 value) {
*(uint32 *)(ptr) = value;
}
FORCEINLINE uint64 READ_UINT64(const void *ptr) {
return *(const uint64 *)(ptr);
}
FORCEINLINE void WRITE_UINT64(void *ptr, uint64 value) {
*(uint64 *)(ptr) = value;
}
// use software fallback by loading each byte explicitely
#else
# if defined(SCUMM_LITTLE_ENDIAN)
inline uint16 READ_UINT16(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[1] << 8) | b[0];
}
inline uint32 READ_UINT32(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[3] << 24) | (b[2] << 16) | (b[1] << 8) | (b[0]);
}
inline void WRITE_UINT16(void *ptr, uint16 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
}
inline void WRITE_UINT32(void *ptr, uint32 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
b[2] = (uint8)(value >> 16);
b[3] = (uint8)(value >> 24);
}
inline uint64 READ_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return ((uint64)b[7] << 56) | ((uint64)b[6] << 48) | ((uint64)b[5] << 40) | ((uint64)b[4] << 32) | ((uint64)b[3] << 24) | ((uint64)b[2] << 16) | ((uint64)b[1] << 8) | ((uint64)b[0]);
}
inline void WRITE_UINT64(void *ptr, uint64 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
b[2] = (uint8)(value >> 16);
b[3] = (uint8)(value >> 24);
b[4] = (uint8)(value >> 32);
b[5] = (uint8)(value >> 40);
b[6] = (uint8)(value >> 48);
b[7] = (uint8)(value >> 56);
}
# elif defined(SCUMM_BIG_ENDIAN)
inline uint16 READ_UINT16(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 8) | b[1];
}
inline uint32 READ_UINT32(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | (b[3]);
}
inline void WRITE_UINT16(void *ptr, uint16 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 8);
b[1] = (uint8)(value >> 0);
}
inline void WRITE_UINT32(void *ptr, uint32 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 24);
b[1] = (uint8)(value >> 16);
b[2] = (uint8)(value >> 8);
b[3] = (uint8)(value >> 0);
}
inline uint64 READ_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return ((uint64)b[0] << 56) | ((uint64)b[1] << 48) | ((uint64)b[2] << 40) | ((uint64)b[3] << 32) | ((uint64)b[4] << 24) | ((uint64)b[5] << 16) | ((uint64)b[6] << 8) | ((uint64)b[7]);
}
inline void WRITE_UINT64(void *ptr, uint64 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 56);
b[1] = (uint8)(value >> 48);
b[2] = (uint8)(value >> 40);
b[3] = (uint8)(value >> 32);
b[4] = (uint8)(value >> 24);
b[5] = (uint8)(value >> 16);
b[6] = (uint8)(value >> 8);
b[7] = (uint8)(value >> 0);
}
# endif
/** @} */
#endif
/** @name Map functions for reading/writing BE/LE integers depending on native endianess
* @{
*/
#if defined(SCUMM_LITTLE_ENDIAN)
#define READ_LE_UINT16(a) READ_UINT16(a)
#define READ_LE_UINT32(a) READ_UINT32(a)
#define WRITE_LE_UINT16(a, v) WRITE_UINT16(a, v)
#define WRITE_LE_UINT32(a, v) WRITE_UINT32(a, v)
#define FROM_LE_32(a) ((uint32)(a))
#define FROM_LE_16(a) ((uint16)(a))
#define FROM_BE_32(a) SWAP_BYTES_32(a)
#define FROM_BE_16(a) SWAP_BYTES_16(a)
#define TO_LE_32(a) ((uint32)(a))
#define TO_LE_16(a) ((uint16)(a))
#define TO_BE_32(a) SWAP_BYTES_32(a)
#define TO_BE_16(a) SWAP_BYTES_16(a)
#define CONSTANT_LE_32(a) ((uint32)(a))
#define CONSTANT_LE_16(a) ((uint16)(a))
#define CONSTANT_BE_32(a) SWAP_CONSTANT_32(a)
#define CONSTANT_BE_16(a) SWAP_CONSTANT_16(a)
#define READ_LE_UINT64(a) READ_UINT64(a)
#define WRITE_LE_UINT64(a, v) WRITE_UINT64(a, v)
#define FROM_LE_64(a) ((uint64)(a))
#define FROM_BE_64(a) SWAP_BYTES_64(a)
#define TO_LE_64(a) ((uint64)(a))
#define TO_BE_64(a) SWAP_BYTES_64(a)
#define CONSTANT_LE_64(a) ((uint64)(a))
#define CONSTANT_BE_64(a) SWAP_CONSTANT_64(a)
/** @} */
/** @name Functions for directly reading/writing and inverting
* @brief Use these in case the unaligned load and byteswap take
* a lot of instructions.
* @{
*/
# if defined(SCUMM_NEED_ALIGNMENT) && !defined(__mips__)
inline uint16 READ_BE_UINT16(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 8) | b[1];
}
inline uint32 READ_BE_UINT32(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | (b[3]);
}
inline void WRITE_BE_UINT16(void *ptr, uint16 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 8);
b[1] = (uint8)(value >> 0);
}
inline void WRITE_BE_UINT32(void *ptr, uint32 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 24);
b[1] = (uint8)(value >> 16);
b[2] = (uint8)(value >> 8);
b[3] = (uint8)(value >> 0);
}
inline uint64 READ_BE_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return ((uint64)b[0] << 56) | ((uint64)b[1] << 48) | ((uint64)b[2] << 40) | ((uint64)b[3] << 32) | ((uint64)b[4] << 24) | ((uint64)b[5] << 16) | ((uint64)b[6] << 8) | ((uint64)b[7]);
}
inline void WRITE_BE_UINT64(void *ptr, uint64 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 56);
b[1] = (uint8)(value >> 48);
b[2] = (uint8)(value >> 40);
b[3] = (uint8)(value >> 32);
b[4] = (uint8)(value >> 24);
b[5] = (uint8)(value >> 16);
b[6] = (uint8)(value >> 8);
b[7] = (uint8)(value >> 0);
}
# else
inline uint16 READ_BE_UINT16(const void *ptr) {
return SWAP_BYTES_16(READ_UINT16(ptr));
}
inline uint32 READ_BE_UINT32(const void *ptr) {
return SWAP_BYTES_32(READ_UINT32(ptr));
}
inline void WRITE_BE_UINT16(void *ptr, uint16 value) {
WRITE_UINT16(ptr, SWAP_BYTES_16(value));
}
inline void WRITE_BE_UINT32(void *ptr, uint32 value) {
WRITE_UINT32(ptr, SWAP_BYTES_32(value));
}
inline uint64 READ_BE_UINT64(const void *ptr) {
return SWAP_BYTES_64(READ_UINT64(ptr));
}
inline void WRITE_BE_UINT64(void *ptr, uint64 value) {
WRITE_UINT64(ptr, SWAP_BYTES_64(value));
}
# endif // if defined(SCUMM_NEED_ALIGNMENT)
#elif defined(SCUMM_BIG_ENDIAN)
#define READ_BE_UINT16(a) READ_UINT16(a)
#define READ_BE_UINT32(a) READ_UINT32(a)
#define WRITE_BE_UINT16(a, v) WRITE_UINT16(a, v)
#define WRITE_BE_UINT32(a, v) WRITE_UINT32(a, v)
#define FROM_LE_32(a) SWAP_BYTES_32(a)
#define FROM_LE_16(a) SWAP_BYTES_16(a)
#define FROM_BE_32(a) ((uint32)(a))
#define FROM_BE_16(a) ((uint16)(a))
#define TO_LE_32(a) SWAP_BYTES_32(a)
#define TO_LE_16(a) SWAP_BYTES_16(a)
#define TO_BE_32(a) ((uint32)(a))
#define TO_BE_16(a) ((uint16)(a))
#define CONSTANT_LE_32(a) SWAP_CONSTANT_32(a)
#define CONSTANT_LE_16(a) SWAP_CONSTANT_16(a)
#define CONSTANT_BE_32(a) ((uint32)(a))
#define CONSTANT_BE_16(a) ((uint16)(a))
#define READ_BE_UINT64(a) READ_UINT64(a)
#define WRITE_BE_UINT64(a, v) WRITE_UINT64(a, v)
#define FROM_LE_64(a) SWAP_BYTES_64(a)
#define FROM_BE_64(a) ((uint64)(a))
#define TO_LE_64(a) SWAP_BYTES_64(a)
#define TO_BE_64(a) ((uint64)(a))
#define CONSTANT_LE_64(a) SWAP_CONSTANT_64(a)
#define CONSTANT_BE_64(a) ((uint64)(a))
// if the unaligned load and the byteswap take a lot of instructions its better to directly read and invert
# if defined(SCUMM_NEED_ALIGNMENT) && !defined(__mips__)
inline uint16 READ_LE_UINT16(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[1] << 8) | b[0];
}
inline uint32 READ_LE_UINT32(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[3] << 24) | (b[2] << 16) | (b[1] << 8) | (b[0]);
}
inline void WRITE_LE_UINT16(void *ptr, uint16 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
}
inline void WRITE_LE_UINT32(void *ptr, uint32 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
b[2] = (uint8)(value >> 16);
b[3] = (uint8)(value >> 24);
}
inline uint64 READ_LE_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return ((uint64)b[7] << 56) | ((uint64)b[6] << 48) | ((uint64)b[5] << 40) | ((uint64)b[4] << 32) | ((uint64)b[3] << 24) | ((uint64)b[2] << 16) | ((uint64)b[1] << 8) | ((uint64)b[0]);
}
inline void WRITE_LE_UINT64(void *ptr, uint64 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
b[2] = (uint8)(value >> 16);
b[3] = (uint8)(value >> 24);
b[4] = (uint8)(value >> 32);
b[5] = (uint8)(value >> 40);
b[6] = (uint8)(value >> 48);
b[7] = (uint8)(value >> 56);
}
# else
inline uint16 READ_LE_UINT16(const void *ptr) {
return SWAP_BYTES_16(READ_UINT16(ptr));
}
inline uint32 READ_LE_UINT32(const void *ptr) {
return SWAP_BYTES_32(READ_UINT32(ptr));
}
inline void WRITE_LE_UINT16(void *ptr, uint16 value) {
WRITE_UINT16(ptr, SWAP_BYTES_16(value));
}
inline void WRITE_LE_UINT32(void *ptr, uint32 value) {
WRITE_UINT32(ptr, SWAP_BYTES_32(value));
}
inline uint64 READ_LE_UINT64(const void *ptr) {
return SWAP_BYTES_64(READ_UINT64(ptr));
}
inline void WRITE_LE_UINT64(void *ptr, uint64 value) {
WRITE_UINT64(ptr, SWAP_BYTES_64(value));
}
# endif // if defined(SCUMM_NEED_ALIGNMENT)
#endif // if defined(SCUMM_LITTLE_ENDIAN)
inline uint32 READ_LE_UINT24(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[2] << 16) | (b[1] << 8) | (b[0]);
}
inline void WRITE_LE_UINT24(void *ptr, uint32 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 0);
b[1] = (uint8)(value >> 8);
b[2] = (uint8)(value >> 16);
}
inline uint32 READ_BE_UINT24(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 16) | (b[1] << 8) | (b[2]);
}
inline void WRITE_BE_UINT24(void *ptr, uint32 value) {
uint8 *b = (uint8 *)ptr;
b[0] = (uint8)(value >> 16);
b[1] = (uint8)(value >> 8);
b[2] = (uint8)(value >> 0);
}
#ifdef SCUMM_LITTLE_ENDIAN
#define READ_UINT24(a) READ_LE_UINT24(a)
#define WRITE_UINT24(a,b) WRITE_LE_UINT24(a,b)
#else
#define READ_UINT24(a) READ_BE_UINT24(a)
#define WRITE_UINT24(a,b) WRITE_BE_UINT24(a,b)
#endif
union SwapFloat {
float f;
uint32 u32;
};
STATIC_ASSERT(sizeof(float) == sizeof(uint32), Unexpected_size_of_float);
inline float READ_LE_FLOAT32(const void *ptr) {
SwapFloat swap;
swap.u32 = READ_LE_UINT32(ptr);
return swap.f;
}
inline void WRITE_LE_FLOAT32(void *ptr, float value) {
SwapFloat swap;
swap.f = value;
WRITE_LE_UINT32(ptr, swap.u32);
}
inline float READ_BE_FLOAT32(const void *ptr) {
SwapFloat swap;
swap.u32 = READ_BE_UINT32(ptr);
return swap.f;
}
inline void WRITE_BE_FLOAT32(void *ptr, float value) {
SwapFloat swap;
swap.f = value;
WRITE_BE_UINT32(ptr, swap.u32);
}
#ifdef SCUMM_LITTLE_ENDIAN
#define READ_FLOAT32(a) READ_LE_FLOAT32(a)
#define WRITE_FLOAT32(a,b) WRITE_LE_FLOAT32(a,b)
#else
#define READ_FLOAT32(a) READ_BE_FLOAT32(a)
#define WRITE_FLOAT32(a,b) WRITE_BE_FLOAT32(a,b)
#endif
#ifdef SCUMM_FLOAT_WORD_LITTLE_ENDIAN
union SwapDouble {
double d;
uint64 u64;
struct {
uint32 low, high;
} u32;
};
#else
union SwapDouble {
double d;
uint64 u64;
struct {
uint32 high, low;
} u32;
};
#endif
STATIC_ASSERT(sizeof(double) == sizeof(uint64) || sizeof(double) == sizeof(uint32), Unexpected_size_of_double);
template<size_t n> inline double READ_DOUBLE(const SwapDouble& sw);
template<size_t n> inline void WRITE_DOUBLE(SwapDouble &sw, double d);
// 64-bit double
template<> inline double READ_DOUBLE<sizeof(uint64)>(const SwapDouble& sd)
{
return sd.d;
}
template<> inline void WRITE_DOUBLE<sizeof(uint64)>(SwapDouble &sd, double d)
{
sd.d = d;
}
// 32-bit double
template<> inline double READ_DOUBLE<sizeof(uint32)>(const SwapDouble& sd)
{
SwapFloat sf;
uint32 e = (sd.u32.high >> 20) & 0x7ff;
if (e <= 896) {
// Too small for normalized, create a zero with the correct sign
// (FIXME: Create denormalized numbers instead when possible?)
sf.u32 = (sd.u32.high & 0x80000000U); // sign bit
return sf.f;
} else if(e >= 1151) {
// Overflow, infinity or NaN
if (e < 2047) {
// Overflow; make sure result is infinity and not NaN
sf.u32 = (sd.u32.high & 0x80000000U) | // sign bit
(255 << 23); // exponent
return sf.f;
}
e = 255;
} else
e -= 896;
sf.u32 = (sd.u32.high & 0x80000000U) | // sign bit
(e << 23) | // exponent
((sd.u32.high & 0xfffff) << 3) | (sd.u32.low >> 29); // mantissa
return sf.f;
}
template<> inline void WRITE_DOUBLE<sizeof(uint32)>(SwapDouble &sd, double d)
{
SwapFloat sf;
sf.f = d;
uint32 e = (sf.u32 >> 23) & 0xff;
if (!e) {
// Denormalized or zero, create a zero with the correct sign
// (FIXME: Convert denormalized 32-bit to normalized 64-bit?)
sd.u32.high = (sf.u32 & 0x80000000U); // sign bit
sd.u32.low = 0;
return;
} else if (e == 255) {
// Infinity or NaN
e = 2047;
} else
e += 896;
sd.u32.high = (sf.u32 & 0x80000000U) | // sign bit
(e << 20) | // exponent
((sf.u32 >> 3) & 0xfffff); // mantissa
sd.u32.low = sf.u32 << 29;
}
inline double READ_LE_FLOAT64(const void *ptr) {
SwapDouble swap;
const uint8 *b = (const uint8 *)ptr;
swap.u32.low = READ_LE_UINT32(b);
swap.u32.high = READ_LE_UINT32(b + 4);
return READ_DOUBLE<sizeof(double)>(swap);
}
inline void WRITE_LE_FLOAT64(void *ptr, double value) {
SwapDouble swap;
WRITE_DOUBLE<sizeof(double)>(swap, value);
uint8 *b = (uint8 *)ptr;
WRITE_LE_UINT32(b, swap.u32.low);
WRITE_LE_UINT32(b + 4, swap.u32.high);
}
inline double READ_BE_FLOAT64(const void *ptr) {
SwapDouble swap;
const uint8 *b = (const uint8 *)ptr;
swap.u32.high = READ_BE_UINT32(b);
swap.u32.low = READ_BE_UINT32(b + 4);
return READ_DOUBLE<sizeof(double)>(swap);
}
inline void WRITE_BE_FLOAT64(void *ptr, double value) {
SwapDouble swap;
WRITE_DOUBLE<sizeof(double)>(swap, value);
uint8 *b = (uint8 *)ptr;
WRITE_BE_UINT32(b, swap.u32.high);
WRITE_BE_UINT32(b + 4, swap.u32.low);
}
inline double READ_FPA_FLOAT64(const void *ptr) {
SwapDouble swap;
const uint8 *b = (const uint8 *)ptr;
swap.u32.high = READ_LE_UINT32(b);
swap.u32.low = READ_LE_UINT32(b + 4);
return READ_DOUBLE<sizeof(double)>(swap);
}
inline void WRITE_FPA_FLOAT64(void *ptr, double value) {
SwapDouble swap;
WRITE_DOUBLE<sizeof(double)>(swap, value);
uint8 *b = (uint8 *)ptr;
WRITE_LE_UINT32(b, swap.u32.high);
WRITE_LE_UINT32(b + 4, swap.u32.low);
}
inline double READ_FLOAT64(const void *ptr) {
SwapDouble swap;
swap.u64 = READ_UINT64(ptr);
return READ_DOUBLE<sizeof(double)>(swap);
}
inline void WRITE_FLOAT64(void *ptr, double value) {
SwapDouble swap;
WRITE_DOUBLE<sizeof(double)>(swap, value);
WRITE_UINT64(ptr, swap.u64);
}
inline int16 READ_LE_INT16(const void *ptr) {
return static_cast<int16>(READ_LE_UINT16(ptr));
}
inline void WRITE_LE_INT16(void *ptr, int16 value) {
WRITE_LE_UINT16(ptr, static_cast<uint16>(value));
}
inline int16 READ_BE_INT16(const void *ptr) {
return static_cast<int16>(READ_BE_UINT16(ptr));
}
inline void WRITE_BE_INT16(void *ptr, int16 value) {
WRITE_BE_UINT16(ptr, static_cast<uint16>(value));
}
inline int32 READ_LE_INT32(const void *ptr) {
return static_cast<int32>(READ_LE_UINT32(ptr));
}
inline void WRITE_LE_INT32(void *ptr, int32 value) {
WRITE_LE_UINT32(ptr, static_cast<uint32>(value));
}
inline int32 READ_BE_INT32(const void *ptr) {
return static_cast<int32>(READ_BE_UINT32(ptr));
}
inline void WRITE_BE_INT32(void *ptr, int32 value) {
WRITE_BE_UINT32(ptr, static_cast<uint32>(value));
}
/** @} */
/** @} */
#endif
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