qzdoom/src/m_swap.h
Christoph Oelckers 833dbee167 - fixed some issues with m_swap's design.
The native byte order converters were defined as macros which hid some issues due to lack of type checks.
Additionally the ???Long variants taking 'long' variables were removed, because longs are not always 32 bits so this could be destructive.
As a result of this, removed several DWORDs from struct definitions in i_crash.cpp.
2018-03-11 14:35:36 +01:00

255 lines
4.4 KiB
C

//
// DESCRIPTION:
// Endianess handling, swapping 16bit and 32bit.
//
//-----------------------------------------------------------------------------
#ifndef __M_SWAP_H__
#define __M_SWAP_H__
#include <stdlib.h>
// Endianess handling.
// WAD files are stored little endian.
#ifdef __APPLE__
#include <libkern/OSByteOrder.h>
inline short LittleShort(short x)
{
return (short)OSSwapLittleToHostInt16((uint16_t)x);
}
inline unsigned short LittleShort(unsigned short x)
{
return OSSwapLittleToHostInt16(x);
}
inline short LittleShort(int x)
{
return OSSwapLittleToHostInt16((uint16_t)x);
}
inline unsigned short LittleShort(unsigned int x)
{
return OSSwapLittleToHostInt16((uint16_t)x);
}
inline int LittleLong(int x)
{
return OSSwapLittleToHostInt32((uint32_t)x);
}
inline unsigned int LittleLong(unsigned int x)
{
return OSSwapLittleToHostInt32(x);
}
inline short BigShort(short x)
{
return (short)OSSwapBigToHostInt16((uint16_t)x);
}
inline unsigned short BigShort(unsigned short x)
{
return OSSwapBigToHostInt16(x);
}
inline int BigLong(int x)
{
return OSSwapBigToHostInt32((uint32_t)x);
}
inline unsigned int BigLong(unsigned int x)
{
return OSSwapBigToHostInt32(x);
}
#elif defined __BIG_ENDIAN__
// Swap 16bit, that is, MSB and LSB byte.
// No masking with 0xFF should be necessary.
inline short LittleShort (short x)
{
return (short)((((unsigned short)x)>>8) | (((unsigned short)x)<<8));
}
inline unsigned short LittleShort (unsigned short x)
{
return (unsigned short)((x>>8) | (x<<8));
}
inline short LittleShort (int x)
{
return LittleShort((short)x);
}
inline unsigned short LittleShort (unsigned int x)
{
return LittleShort((unsigned short)x);
}
// Swapping 32bit.
inline unsigned int LittleLong (unsigned int x)
{
return (unsigned int)(
(x>>24)
| ((x>>8) & 0xff00)
| ((x<<8) & 0xff0000)
| (x<<24));
}
inline int LittleLong (int x)
{
return (int)(
(((unsigned int)x)>>24)
| ((((unsigned int)x)>>8) & 0xff00)
| ((((unsigned int)x)<<8) & 0xff0000)
| (((unsigned int)x)<<24));
}
inline short BigShort(short x)
{
return x;
}
inline unsigned short BigShort(unsigned short x)
{
return x;
}
inline unsigned int BigLong(unsigned int &x)
{
return x;
}
inline int BigLong(int &x)
{
return x;
}
#else
inline short LittleShort(short x)
{
return x;
}
inline unsigned short LittleShort(unsigned short x)
{
return x;
}
inline unsigned int LittleLong(unsigned int x)
{
return x;
}
inline int LittleLong(int x)
{
return x;
}
#ifdef _MSC_VER
inline short BigShort(short x)
{
return (short)_byteswap_ushort((unsigned short)x);
}
inline unsigned short BigShort(unsigned short x)
{
return _byteswap_ushort(x);
}
inline int BigLong(int x)
{
return (int)_byteswap_ulong((unsigned long)x);
}
inline unsigned int BigLong(unsigned int x)
{
return (unsigned int)_byteswap_ulong((unsigned long)x);
}
#pragma warning (default: 4035)
#else
inline short BigShort (short x)
{
return (short)((((unsigned short)x)>>8) | (((unsigned short)x)<<8));
}
inline unsigned short BigShort (unsigned short x)
{
return (unsigned short)((x>>8) | (x<<8));
}
inline unsigned int BigLong (unsigned int x)
{
return (unsigned int)(
(x>>24)
| ((x>>8) & 0xff00)
| ((x<<8) & 0xff0000)
| (x<<24));
}
inline int BigLong (int x)
{
return (int)(
(((unsigned int)x)>>24)
| ((((unsigned int)x)>>8) & 0xff00)
| ((((unsigned int)x)<<8) & 0xff0000)
| (((unsigned int)x)<<24));
}
#endif
#endif // __BIG_ENDIAN__
// These may be destructive so they should create errors
unsigned long BigLong(unsigned long) = delete;
long BigLong(long) = delete;
unsigned long LittleLong(unsigned long) = delete;
long LittleLong(long) = delete;
// Data accessors, since some data is highly likely to be unaligned.
#if defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || defined(__x86_64__)
inline int GetShort(const unsigned char *foo)
{
return *(const short *)foo;
}
inline int GetInt(const unsigned char *foo)
{
return *(const int *)foo;
}
#else
inline int GetShort(const unsigned char *foo)
{
return short(foo[0] | (foo[1] << 8));
}
inline int GetInt(const unsigned char *foo)
{
return int(foo[0] | (foo[1] << 8) | (foo[2] << 16) | (foo[3] << 24));
}
#endif
inline int GetBigInt(const unsigned char *foo)
{
return int((foo[0] << 24) | (foo[1] << 16) | (foo[2] << 8) | foo[3]);
}
#ifdef __BIG_ENDIAN__
inline int GetNativeInt(const unsigned char *foo)
{
return GetBigInt(foo);
}
#else
inline int GetNativeInt(const unsigned char *foo)
{
return GetInt(foo);
}
#endif
#endif // __M_SWAP_H__