scummvm/common/endian.h

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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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
2006-04-15 21:22:33 +00:00
#ifndef COMMON_ENDIAN_H
#define COMMON_ENDIAN_H
#include "common/scummsys.h"
/**
* \file endian.h
* Endian conversion and byteswap conversion functions or macros
*
* SWAP_BYTES_??(a) - inverse byte order
* SWAP_CONSTANT_??(a) - inverse byte order, implemented as macro.
* Use with compiletime-constants only, the result will be a compiletime-constant aswell.
* Unlike most other functions these can be used for eg. switch-case labels
*
* READ_UINT??(a) - read native value from pointer a
* READ_??_UINT??(a) - read LE/BE value from pointer a and convert it to native
* WRITE_??_UINT??(a, v) - write native value v to pointer a with LE/BE encoding
* TO_??_??(a) - convert native value v to LE/BE
* FROM_??_??(a) - convert LE/BE value v to native
* CONSTANT_??_??(a) - convert LE/BE value v to native, implemented as macro.
* Use with compiletime-constants only, the result will be a compiletime-constant aswell.
* Unlike most other functions these can be used for eg. switch-case labels
*/
// Sanity check
#if !defined(SCUMM_LITTLE_ENDIAN) && !defined(SCUMM_BIG_ENDIAN)
# error No endianness defined
#endif
#ifdef HAVE_INT64
#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) ))
#endif
#define SWAP_CONSTANT_32(a) \
((uint32)((((a) >> 24) & 0x00FF) | \
(((a) >> 8) & 0xFF00) | \
(((a) & 0xFF00) << 8) | \
(((a) & 0x00FF) << 24) ))
#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.
*/
// compilerspecific variants come first, fallback last
// Test for GCC and if the target has the MIPS rel.2 instructions (we know the psp does)
#if defined(__GNUC__) && (defined(__psp__) || defined(_MIPS_ARCH_MIPS32R2) || defined(_MIPS_ARCH_MIPS64R2))
FORCEINLINE uint16 SWAP_BYTES_16(const uint16 a) {
if (__builtin_constant_p(a)) {
return SWAP_CONSTANT_16(a);
} else {
uint16 result;
__asm__ ("wsbh %0,%1" : "=r" (result) : "r" (a));
return result;
}
}
#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.
*/
// machine/compiler-specific variants come first, fallback last
// Test for GCC and if the target has the MIPS rel.2 instructions (we know the psp does)
#if defined(__GNUC__) && (defined(__psp__) || defined(_MIPS_ARCH_MIPS32R2) || defined(_MIPS_ARCH_MIPS64R2))
FORCEINLINE uint32 SWAP_BYTES_32(const uint32 a) {
if (__builtin_constant_p(a)) {
return SWAP_CONSTANT_32(a);
} else {
uint32 result;
# if defined(__psp__)
// use special allegrex instruction
__asm__ ("wsbw %0,%1" : "=r" (result) : "r" (a));
# else
__asm__ ("wsbh %0,%1\n"
"rotr %0,%0,16" : "=r" (result) : "r" (a));
# endif
return result;
}
}
// Test for GCC >= 4.3.0 as this version added the bswap builtin
2012-03-15 09:16:45 +00:00
#elif GCC_ATLEAST(4, 3)
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
#ifdef HAVE_INT64
/**
* Swap the bytes in a 64 bit word in order to convert LE encoded data to BE
* and vice versa.
*/
// machine/compiler-specific variants come first, fallback last
// Test for GCC and if the target has the MIPS rel.2 instructions (we know the psp does)
//
// TODO: Fix this #if statement. It isn't changed from 32 bit. Is there a 64 bit swap instruction?
#if defined(__GNUC__) && (defined(__psp__) || defined(_MIPS_ARCH_MIPS32R2) || defined(_MIPS_ARCH_MIPS64R2))
FORCEINLINE uint32 SWAP_BYTES_32(const uint32 a) {
if (__builtin_constant_p(a)) {
return SWAP_CONSTANT_32(a);
} else {
uint32 result;
# if defined(__psp__)
// use special allegrex instruction
__asm__ ("wsbw %0,%1" : "=r" (result) : "r" (a));
# else
__asm__ ("wsbh %0,%1\n"
"rotr %0,%0,16" : "=r" (result) : "r" (a));
# endif
return result;
}
}
// Test for GCC >= 4.3.0 as this version added the bswap builtin
#elif GCC_ATLEAST(4, 3)
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
#endif // HAVE_INT64
/**
* A wrapper macro used around four character constants, like 'DATA', to
* ensure portability. Typical usage: MKTAG('D','A','T','A').
*
* Why is this necessary? 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)))
// Functions for reading/writing native integers.
// They also transparently handle the need for alignment.
// Test for GCC >= 4.0. These implementations will automatically use
// CPU-specific instructions for unaligned data when they are available (eg.
// MIPS). See also this email thread on scummvm-devel for details:
// <http://thread.gmane.org/gmane.games.devel.scummvm/8063>
//
// Moreover, we activate this code for GCC >= 3.3 but *only* if unaligned access
// is allowed.
2012-03-15 09:16:45 +00:00
#if GCC_ATLEAST(4, 0) || (GCC_ATLEAST(3, 3) && !defined(SCUMM_NEED_ALIGNMENT))
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;
}
#ifdef HAVE_INT64
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;
}
#endif
#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;
}
#ifdef HAVE_INT64
FORCEINLINE uint64 READ_UINT64(const void *ptr) {
return *(const uint64 *)(ptr);
}
FORCEINLINE void WRITE_UINT64(void *ptr, uint64 value) {
*(uint64 *)(ptr) = value;
}
#endif
// 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);
}
#ifdef HAVE_INT64
inline uint64 READ_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[7] << 56) | (b[6] << 48) | (b[5] << 40) | (b[4] << 32) | (b[3] << 24) | (b[2] << 16) | (b[1] << 8) | (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);
}
#endif
# 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);
}
#ifdef HAVE_INT64
inline uint64 READ_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 56) | (b[1] << 48) | (b[2] << 40) | (b[3] << 32) | (b[4] << 24) | (b[5] << 16) | (b[6] << 8) | (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
#endif
// Map Funtions 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)
#ifdef HAVE_INT64
#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)
#endif
// if the unaligned load and the byteswap take alot instructions its better to directly read and invert
# 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);
}
#ifdef HAVE_INT64
inline uint64 READ_BE_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 56) | (b[1] << 48) | (b[2] << 40) | (b[3] << 32) | (b[4] << 24) | (b[5] << 16) | (b[6] << 8) | (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);
}
#endif
# 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));
}
#ifdef HAVE_INT64
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
# 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))
#ifdef HAVE_INT64
#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))
#endif
// if the unaligned load and the byteswap take alot 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);
}
#ifdef HAVE_INT64
inline uint64 READ_LE_UINT64(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[7] << 56) | (b[6] << 48) | (b[5] << 40) | (b[4] << 32) | (b[3] << 24) | (b[2] << 16) | (b[1] << 8) | (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);
}
#endif
# 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));
}
#ifdef HAVE_INT64
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
# 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 uint32 READ_BE_UINT24(const void *ptr) {
const uint8 *b = (const uint8 *)ptr;
return (b[0] << 16) | (b[1] << 8) | (b[2]);
}
#ifdef SCUMM_LITTLE_ENDIAN
#define READ_UINT24(a) READ_LE_UINT24(a)
#else
#define READ_UINT24(a) READ_BE_UINT24(a)
#endif
#endif