/**
* Runs the instruction at the program counters position in memory.
*/
void vm_exec()
{
cycles++;
Instruction* op = mem_load_instr(pcounter);
print_instr(op);
switch(op->op)
{
case OP_NAP: break;
case OP_ADD: op_add(op); break;
case OP_SUB: op_sub(op); break;
case OP_EXP: op_exp(op); break;
case OP_SIN: op_sin(op); break;
case OP_COS: op_cos(op); break;
case OP_TAN: op_tan(op); break;
case OP_LW: op_lw(op); break;
case OP_SW: op_sw(op); break;
case OP_SB: op_sb(op); break;
case OP_J: op_j(op); return; // Jump
case OP_JR: op_jr(op); return;
case OP_JAL: op_jal(op); return;
case OP_JZ: op_jz(op); return;
case OP_JNZ: op_jnz(op); return;
case OP_JEQ: op_jeq(op); return;
case OP_JNQ: op_jnq(op); return;
case OP_PUSH: op_push(op); break;
case OP_POP: op_pop(op); break;
case OP_PRTI: op_prti(op); break;
case OP_EXIT:
vm_exit(op->k);
return;
/* Unsupported operation */
default:
printf("Error: Invalid operation at %d\n", pcounter);
print_instr(op);
vm_exit(-1);
return;
}
pcounter = pcounter + 8;
}
void process_instruction(){
//1. Fetch instruction
instruction instr = INST_INFO[(CURRENT_STATE.PC - MEM_TEXT_START)/4];
//printf("opcode: %x\n",instr.opcode);
//2. PC update
CURRENT_STATE.PC += 4;
//3. Perform operation
//3-1. R-type running
if(instr.opcode == 0x0)
{
unsigned char rd, rs, rt, shamt;
shamt = instr.r_t.r_i.r_i.r.shamt;
rd = instr.r_t.r_i.r_i.r.rd;
rs = instr.r_t.r_i.rs;
rt = instr.r_t.r_i.rt;
void (*operation)(unsigned char, unsigned char, unsigned char);
if(instr.r_t.r_i.r_i.r.shamt == 0)
{
switch(instr.func_code)
{
case 0x21:
operation = op_addu;
break;
case 0x24:
operation = op_and;
break;
case 0x8:
operation = op_jr;
break;
case 0x27:
operation = op_nor;
break;
case 0x25:
operation = op_or;
break;
case 0x23:
operation = op_subu;
break;
case 0x2B:
operation = op_sltu;
break;
};
operation(rd, rs, rt);
}
else
{
if(instr.func_code == 0) operation = op_sll;
else op_srl;
operation(rd, rt, shamt);
}
}
//3-2. J-type running
else if(instr.opcode == 0x2 || instr.opcode == 0x3)
{
void (*operation)(uint32_t);
uint32_t target = instr.r_t.target;
if(instr.opcode == 0x2)
{
op_j(target);
}
else
{
op_jal(target);
}
}
//3-3. I-type running
else
{
void (*operation)(unsigned char, unsigned char, short);
unsigned char rt, rs;
short imm;
rt = instr.r_t.r_i.rt;
rs = instr.r_t.r_i.rs;
imm = instr.r_t.r_i.r_i.imm;
switch(instr.opcode)
{
case 0x9:
operation = op_addiu;
break;
case 0x4:
operation = op_beq;
break;
case 0x5:
operation = op_bne;
break;
case 0x23:
operation = op_lw;
break;
case 0xB:
operation = op_sltiu;
break;
case 0x2B:
operation = op_sw;
break;
case 0xF:
operation = op_lui;
break;
case 0xD:
operation = op_ori;
break;
case 0xC:
operation = op_andi;
break;
};
operation(rt, rs, imm);
}
if(CURRENT_STATE.PC - MEM_TEXT_START == NUM_INST * 4) {
RUN_BIT = false;
return;
}
}
void doop(Mips * emu, uint32_t op) {
switch(op & 0xfc000000) {
case 0x8000000:
op_j(emu,op);
return;
case 0xc000000:
op_jal(emu,op);
return;
case 0x10000000:
op_beq(emu,op);
return;
case 0x14000000:
op_bne(emu,op);
return;
case 0x18000000:
op_blez(emu,op);
return;
case 0x1c000000:
op_bgtz(emu,op);
return;
case 0x20000000:
op_addi(emu,op);
return;
case 0x24000000:
op_addiu(emu,op);
return;
case 0x28000000:
op_slti(emu,op);
return;
case 0x2c000000:
op_sltiu(emu,op);
return;
case 0x30000000:
op_andi(emu,op);
return;
case 0x34000000:
op_ori(emu,op);
return;
case 0x38000000:
op_xori(emu,op);
return;
case 0x3c000000:
op_lui(emu,op);
return;
case 0x50000000:
op_beql(emu,op);
return;
case 0x54000000:
op_bnel(emu,op);
return;
case 0x58000000:
op_blezl(emu,op);
return;
case 0x80000000:
op_lb(emu,op);
return;
case 0x84000000:
op_lh(emu,op);
return;
case 0x88000000:
op_lwl(emu,op);
return;
case 0x8c000000:
op_lw(emu,op);
return;
case 0x90000000:
op_lbu(emu,op);
return;
case 0x94000000:
op_lhu(emu,op);
return;
case 0x98000000:
op_lwr(emu,op);
return;
case 0xa0000000:
op_sb(emu,op);
return;
case 0xa4000000:
op_sh(emu,op);
return;
case 0xa8000000:
op_swl(emu,op);
return;
case 0xac000000:
op_sw(emu,op);
return;
case 0xb8000000:
op_swr(emu,op);
return;
case 0xbc000000:
op_cache(emu,op);
return;
case 0xc0000000:
op_ll(emu,op);
return;
case 0xcc000000:
op_pref(emu,op);
return;
case 0xe0000000:
op_sc(emu,op);
return;
}
switch(op & 0xfc00003f) {
case 0x0:
op_sll(emu,op);
return;
case 0x2:
op_srl(emu,op);
return;
case 0x3:
op_sra(emu,op);
return;
case 0x4:
op_sllv(emu,op);
return;
case 0x6:
op_srlv(emu,op);
return;
case 0x7:
op_srav(emu,op);
return;
case 0x8:
op_jr(emu,op);
return;
case 0x9:
op_jalr(emu,op);
return;
case 0xc:
op_syscall(emu,op);
return;
case 0xf:
op_sync(emu,op);
return;
case 0x10:
op_mfhi(emu,op);
return;
case 0x11:
op_mthi(emu,op);
return;
case 0x12:
op_mflo(emu,op);
return;
case 0x13:
op_mtlo(emu,op);
return;
case 0x18:
op_mult(emu,op);
return;
case 0x19:
op_multu(emu,op);
return;
case 0x1a:
op_div(emu,op);
return;
case 0x1b:
op_divu(emu,op);
return;
case 0x20:
op_add(emu,op);
return;
case 0x21:
op_addu(emu,op);
return;
case 0x22:
op_sub(emu,op);
return;
case 0x23:
op_subu(emu,op);
return;
case 0x24:
op_and(emu,op);
return;
case 0x25:
op_or(emu,op);
return;
case 0x26:
op_xor(emu,op);
return;
case 0x27:
op_nor(emu,op);
return;
case 0x2a:
op_slt(emu,op);
return;
case 0x2b:
op_sltu(emu,op);
return;
case 0x2d:
op_addu(emu,op); //daddu
return;
case 0x36:
op_tne(emu,op);
return;
}
switch(op & 0xfc1f0000) {
case 0x4000000:
op_bltz(emu,op);
return;
case 0x4010000:
op_bgez(emu,op);
return;
case 0x4020000:
op_bltzl(emu,op);
return;
case 0x4030000:
op_bgezl(emu,op);
return;
case 0x4100000:
op_bltzal(emu,op);
return;
case 0x4110000:
op_bgezal(emu,op);
return;
case 0x5c000000:
op_bgtzl(emu,op);
return;
}
switch(op & 0xffffffff) {
case 0x42000002:
op_tlbwi(emu,op);
return;
case 0x42000006:
op_tlbwr(emu,op);
return;
case 0x42000008:
op_tlbp(emu,op);
return;
case 0x42000018:
op_eret(emu,op);
return;
}
switch(op & 0xfc0007ff) {
case 0xa:
op_movz(emu,op);
return;
case 0xb:
op_movn(emu,op);
return;
case 0x70000002:
op_mul(emu,op);
return;
}
switch(op & 0xffe00000) {
case 0x40000000:
op_mfc0(emu,op);
return;
case 0x40800000:
op_mtc0(emu,op);
return;
}
switch(op & 0xfe00003f) {
case 0x42000020:
op_wait(emu,op);
return;
}
// printf("unhandled opcode at %x -> %x\n",emu->pc,op);
setExceptionCode(emu,EXC_RI);
emu->exceptionOccured = 1;
return;
}