BizHawk/psx/octoshock/endian.cpp

152 lines
2.8 KiB
C++

/* Mednafen - Multi-system Emulator
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include "octoshock.h"
#include "endian.h"
void Endian_A16_Swap(void *src, uint32 nelements)
{
uint32 i;
uint8 *nsrc = (uint8 *)src;
for(i = 0; i < nelements; i++)
{
uint8 tmp = nsrc[i * 2];
nsrc[i * 2] = nsrc[i * 2 + 1];
nsrc[i * 2 + 1] = tmp;
}
}
void Endian_A32_Swap(void *src, uint32 nelements)
{
uint32 i;
uint8 *nsrc = (uint8 *)src;
for(i = 0; i < nelements; i++)
{
uint8 tmp1 = nsrc[i * 4];
uint8 tmp2 = nsrc[i * 4 + 1];
nsrc[i * 4] = nsrc[i * 4 + 3];
nsrc[i * 4 + 1] = nsrc[i * 4 + 2];
nsrc[i * 4 + 2] = tmp2;
nsrc[i * 4 + 3] = tmp1;
}
}
void Endian_A64_Swap(void *src, uint32 nelements)
{
uint32 i;
uint8 *nsrc = (uint8 *)src;
for(i = 0; i < nelements; i++)
{
uint8 *base = &nsrc[i * 8];
for(int z = 0; z < 4; z++)
{
uint8 tmp = base[z];
base[z] = base[7 - z];
base[7 - z] = tmp;
}
}
}
void Endian_A16_NE_LE(void *src, uint32 nelements)
{
#ifdef MSB_FIRST
Endian_A16_Swap(src, nelements);
#endif
}
void Endian_A32_NE_LE(void *src, uint32 nelements)
{
#ifdef MSB_FIRST
Endian_A32_Swap(src, nelements);
#endif
}
void Endian_A64_NE_LE(void *src, uint32 nelements)
{
#ifdef MSB_FIRST
Endian_A64_Swap(src, nelements);
#endif
}
//
//
//
void Endian_A16_NE_BE(void *src, uint32 nelements)
{
#ifdef LSB_FIRST
Endian_A16_Swap(src, nelements);
#endif
}
void Endian_A32_NE_BE(void *src, uint32 nelements)
{
#ifdef LSB_FIRST
Endian_A32_Swap(src, nelements);
#endif
}
void Endian_A64_NE_BE(void *src, uint32 nelements)
{
#ifdef LSB_FIRST
Endian_A64_Swap(src, nelements);
#endif
}
static void FlipByteOrder(uint8 *src, uint32 count)
{
uint8 *start=src;
uint8 *end=src+count-1;
if((count&1) || !count) return; /* This shouldn't happen. */
count >>= 1;
while(count--)
{
uint8 tmp;
tmp=*end;
*end=*start;
*start=tmp;
end--;
start++;
}
}
void Endian_V_NE_LE(void *src, uint32 bytesize)
{
#ifdef MSB_FIRST
FlipByteOrder((uint8 *)src, bytesize);
#endif
}
void Endian_V_NE_BE(void *src, uint32 bytesize)
{
#ifdef LSB_FIRST
FlipByteOrder((uint8 *)src, bytesize);
#endif
}