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#include "68kinst.h"
void m68k_decode_op(uint16_t op, m68k_op_info *dst)
{
uint8_t mode = (op >> 3) & 0x7;
uint8_t reg = op & 0x7;
dst->addr_mode = mode;
switch(mode)
{
case MODE_REG:
case MODE_AREG:
dst->params.regs.pri = reg;
break;
case MODE_
}
}
uint16_t * m68K_decode(uint16_t * istream, m68kinst * decoded)
{
uint8_t optype = *istream >> 12;
uint8_t size;
uint8_t immed;
switch(optype)
{
case BIT_MOVEP_IMMED:
//TODO: Implement me
break;
case MOVE_BYTE:
case MOVE_LONG:
case MOVE_WORD:
decoded->op = M68K_MOVE;
decoded->extra.size = optype == MOVE_BYTE ? OPSIZE_BYTE : (optype == MOVE_WORD ? OPSIZE_WORD : OPSIZE_LONG);
m68k_decode_op(*istream, &(decoded->src));
m68k_decode_op(((*istream >> 9) & 0x7) | , &(decoded->dst));
break;
case MISC:
//TODO: Implement me
break;
case QUICK_ARITH_LOOP:
size = (*istream >> 6) & 3;
if (size == 0x3) {
//DBcc, TRAPcc or Scc
decoded->extra.cond = (*istream >> 0x8) & 0xF;
switch ((*istream >> 3) & 0x7)
{
case 1: //DBcc
decoded->op = M68K_DBCC;
decoded->dst.addr_mode = MODE_REG;
decoded->dst.regs.pri = *istream & 0x7;
break;
case 7: //TRAPcc
decoded->op = M68K_TRAPCC;
decoded->src.addr_mode = MODE_PC_INDIRECT_ABS_IMMED;
decoded->src.regs.pri = MODE_IMMEDIATE;
//TODO: Figure out what to do with OPMODE and optional extention words
break;
default: //Scc
decoded->op = M68K_SCC;
M68k_decode_op(*istream, &(decoded->dst));
break;
}
} else {
//ADDQ, SUBQ
decoded->variant = VAR_QUICK;
decoded->extra.size = size;
decoded->src.addr_mode = MODE_PC_INDIRECT_ABS_IMMED;
decoded->src.regs.pri = MODE_IMMEDIATE;
immed = (*istream >> 9) & 0x7
if (!immed) {
immed = 8;
}
switch (size)
{
case OPSIZE_BYTE;
decoded->src.params.u8 = immed;
break;
case OPSIZE_WORD:
decoded->src.params.u16 = immed;
break;
case OPSIZE_LONG:
decoded->src.params.u38 = immed;
break;
}
if (*istream & 0x10) {
decoded->op = M68K_SUB;
} else {
decoded->op = M68K_ADD;
}
}
break;
}
}
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