/*
* nexti: execute single instruction and return status.
* args
* sim: the y86 image with PC, register and memory
*
* return
* STAT_AOK: continue
* STAT_HLT: halt
* STAT_ADR: invalid instruction address
* STAT_INS: invalid instruction, register id, data address, stack address, ...
*/
stat_t nexti(y86sim_t *sim)
{
byte_t codefun = 0;
itype_t icode;
alu_t ifun;
long_t next_pc = sim->pc;
regid_t rA = REG_NONE;
regid_t rB = REG_NONE;
long_t im_value = 0;
/* get code and function (1 byte) */
if (!get_byte_val(sim->m, next_pc, &codefun)) {
err_print("PC = 0x%x, Invalid instruction address", sim->pc);
return STAT_ADR;
}
icode = GET_ICODE(codefun);
ifun = GET_FUN(codefun);
next_pc++;
/* get registers if needed (1 byte) */
byte_t reg = 0;
switch (icode)
{
case I_RRMOVL:
case I_IRMOVL:
case I_RMMOVL:
case I_MRMOVL:
case I_ALU:
case I_PUSHL:
case I_POPL:
if(!get_byte_val(sim->m, next_pc, ®)) {
err_print("PC = 0x%x, Invalid instruction address", sim->pc);
return STAT_ADR;
}
rA = GET_REGA(reg);
rB = GET_REGB(reg);
next_pc++;
case I_HALT:case I_NOP:case I_JMP:case I_CALL:case I_RET:default:
break;
}
/* get immediate if needed (4 bytes) */
switch(icode)
{
case I_IRMOVL:
case I_RMMOVL:
case I_MRMOVL:
case I_JMP:
case I_CALL:
if(!get_long_val(sim->m, next_pc, &im_value)) {
err_print("PC = 0x%x, Invalid instruction address", sim->pc); return STAT_ADR;
}
next_pc += 4;
case I_HALT:case I_NOP:case I_RRMOVL:case I_ALU:
case I_RET:case I_PUSHL:case I_POPL:default:
break;
}
/* execute the instruction */
switch (icode) {
case I_HALT: /* 0:0 */
return STAT_HLT;
break;
case I_NOP: /* 1:0 */
sim->pc = next_pc;
break;
case I_RRMOVL:/* 2:x regA:regB */
{
long_t rr_temp = get_reg_val(sim->r, rA);
if (cond_doit(sim->cc, ifun))
set_reg_val(sim->r, rB, rr_temp);
sim->pc = next_pc;
break;
}
case I_IRMOVL: /* 3:0 F:regB imm */
{
set_reg_val(sim->r, rB, im_value);
sim->pc = next_pc;
break;
}
case I_RMMOVL: /* 4:0 regA:regB imm */
{
long_t rm_temp_rA = get_reg_val(sim->r, rA);
long_t rm_temp_rB = get_reg_val(sim->r, rB);
set_long_val(sim->m, im_value+rm_temp_rB, rm_temp_rA);
sim->pc = next_pc;
break;
}
case I_MRMOVL: /* 5:0 regB:regA imm */
{
long_t mr_temp_rB = get_reg_val(sim->r, rB);
long_t temp_val = 0;
if(!get_long_val(sim->m, im_value+mr_temp_rB, &temp_val))
{
err_print("PC = 0x%x, Invalid data address 0x%x", sim->pc, im_value+mr_temp_rB);
return STAT_ADR;
}
set_reg_val(sim->r, rA, temp_val);
sim->pc = next_pc;
break;
}
case I_ALU: /* 6:x regA:regB */
{
long_t rA_val = get_reg_val(sim->r, rA);
long_t rB_val = get_reg_val(sim->r, rB);
long_t alu_result = 0;
switch (ifun)
{
case A_ADD:case A_SUB:case A_AND:case A_XOR:
alu_result = compute_alu(ifun, rA_val, rB_val);
set_reg_val(sim->r, rB, alu_result);
break;
case A_NONE:default:
return STAT_INS;
}
sim->cc = compute_cc(ifun, rA_val, rB_val, alu_result);
sim->pc = next_pc;
break;
}
case I_JMP: /* 7:x imm */
{
if (cond_doit(sim->cc, ifun))
sim->pc = im_value;
else
sim->pc=next_pc;
break;
}
case I_CALL: /* 8:x imm */
{
long_t esp = get_reg_val(sim->r, REG_ESP);
esp -= 4;
set_reg_val(sim->r, REG_ESP, esp);
if (esp < 0)
{
err_print("PC = 0x%x, Invalid stack address 0x%x", sim->pc, esp);
return STAT_ADR;
}
set_long_val(sim->m, esp, next_pc);
sim->pc = im_value;
break;
}
case I_RET: /* 9:0 */
{
long_t esp = get_reg_val(sim->r, REG_ESP);
long_t return_value = 0;
if(!get_long_val(sim->m, esp, &return_value))
{
err_print("PC = 0x%x, Invalid data address 0x%x", sim->pc, esp);
return STAT_ADR;
}
esp += 4;
set_reg_val(sim->r, REG_ESP, esp);
if (esp < 0)
{
err_print("PC = 0x%x, Invalid stack address 0x%x", sim->pc, esp);
return STAT_ADR;
}
sim->pc = return_value;
break;
}
case I_PUSHL: /* A:0 regA:F */
{
long_t esp = get_reg_val(sim->r, REG_ESP);
long_t rA_value = get_reg_val(sim->r, rA);
esp -= 4;
set_reg_val(sim->r, REG_ESP, esp);
if (esp < 0)
{
err_print("PC = 0x%x, Invalid stack address 0x%x", sim->pc, esp);
return STAT_ADR;
}
set_long_val(sim->m, esp, rA_value);
sim->pc = next_pc;
break;
}
case I_POPL: /* B:0 regA:F */
{
long_t esp = get_reg_val(sim->r, REG_ESP);
long_t temp_value = 0;
if(!get_long_val(sim->m, esp, &temp_value))
{
err_print("PC = 0x%x, Invalid instruction address", esp);
return STAT_ADR;
}
esp += 4;
set_reg_val(sim->r, REG_ESP, esp);
if (esp < 0)
{
err_print("PC = 0x%x, Invalid stack address 0x%x", sim->pc, esp);
return STAT_ADR;
}
set_reg_val(sim->r, rA, temp_value);
sim->pc = next_pc;
break;
}
return STAT_INS; /* unsupported now, replace it with your implementation */
break;
default:
err_print("PC = 0x%x, Invalid instruction %.2x", sim->pc, codefun);
return STAT_INS;
}
return STAT_AOK;
}
/*
* nexti: execute single instruction and return status.
* args
* sim: the y64 image with PC, register and memory
*
* return
* STAT_AOK: continue
* STAT_HLT: halt
* STAT_ADR: invalid instruction address
* STAT_INS: invalid instruction, register id, data address, stack address, ...
*/
stat_t nexti(y64sim_t *sim)
{
byte_t codefun = 0; /* 1 byte */
itype_t icode;
alu_t ifun;
long_t next_pc = sim->pc;
/* get code and function （1 byte) */
if (!get_byte_val(sim->m, next_pc, &codefun)) {
err_print("PC = 0x%lx, Invalid instruction address", sim->pc);
return STAT_ADR;
}
icode = GET_ICODE(codefun);
ifun = GET_FUN(codefun);
next_pc++;
/* get registers if needed (1 byte) */
byte_t rArB = 0;
regid_t rA = REG_ERR, rB = REG_ERR;
if((icode == I_RRMOVQ) || (icode == I_ALU) || (icode == I_RMMOVQ) ||
(icode == I_PUSHQ) || (icode == I_POPQ) ||
(icode == I_IRMOVQ) || (icode == I_MRMOVQ) ){
get_byte_val(sim->m, next_pc, &rArB);
rA = GET_REGA(rArB);
rB = GET_REGB(rArB);
next_pc++;
}
/* get immediate if needed (8 bytes) */
long_t valC;
if(icode == I_IRMOVQ || icode == I_RMMOVQ ||icode == I_MRMOVQ ||
icode == I_JMP || icode == I_CALL){
get_long_val(sim->m,next_pc,&valC);
next_pc += 8;
}
/* execute the instruction*/
long_t valA,valB,valE,valM;
switch (icode) {
case I_HALT: /* 0:0 */
return STAT_HLT;
break;
case I_NOP: /* 1:0 */
sim->pc = next_pc;
break;
case I_RRMOVQ: /* 2:x regA:regB */
if(!NORM_REG(rA) || !NORM_REG(rB)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r,rA);
valE = valA + 0;
if(cond_doit(sim->cc, ifun))
set_reg_val(sim->r, rB, valE);
sim->pc = next_pc;
break;
case I_IRMOVQ: /* 3:0 F:regB imm */
if(!NORM_REG(rB) || !NONE_REG(rA)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r, rA);
valB = get_reg_val(sim->r, rB);
valE = 0 + valC;
set_reg_val(sim->r, rB, valE);
sim->pc = next_pc;
break;
case I_RMMOVQ: /* 4:0 regA:regB imm */
if(!NORM_REG(rA) || !NORM_REG(rB)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r, rA);
valB = get_reg_val(sim->r, rB);
valE = valB + valC;
if(!set_long_val(sim->m, valE, valA)){
err_print("PC = 0x%lx, Invalid data address 0x%.8lx", sim->pc, valE);
return STAT_ADR;
}
sim->pc = next_pc;
break;
case I_MRMOVQ: /* 5:0 regB:regA imm */
if(!NORM_REG(rA) || !NORM_REG(rB)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r, rA);
valB = get_reg_val(sim->r, rB);
valE = valB + valC;
if(!get_long_val(sim->m, valE, &valM)){
err_print("PC = 0x%lx, Invalid data address 0x%.8lx", sim->pc, valE);
return STAT_ADR;
}
set_reg_val(sim->r, rA, valM);
sim->pc = next_pc;
break;
case I_ALU: /* 6:x regA:regB */
if(!NORM_REG(rA) || !NORM_REG(rB)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r, rA);
valB = get_reg_val(sim->r, rB);
valE = compute_alu(ifun, valA, valB);
sim->cc = compute_cc(ifun, valA, valB, valE);
set_reg_val(sim->r, rB, valE);
sim->pc = next_pc;
break;
case I_JMP: /* 7:x imm */
if(ifun > 6){
err_print("PC = 0x%lx, Invalid instruction %.2x", sim->pc, codefun);
return STAT_INS;
}
sim->pc = cond_doit(sim->cc,ifun)? valC : next_pc;
break;
case I_CALL: /* 8:x imm */
valB = get_reg_val(sim->r, REG_RSP);
valE = valB + (-8);
set_reg_val(sim->r, REG_RSP, valE);
if(!set_long_val(sim->m, valE, next_pc)){
err_print("PC = 0x%lx, Invalid stack address 0x%.8lx", sim->pc, valE);
return STAT_ADR;
}
sim->pc = valC;
break;
case I_RET: /* 9:0 */
valA = get_reg_val(sim->r, REG_RSP);
valB = valA;
valE = valB + 8;
get_long_val(sim->m, valA, &valM);
set_reg_val(sim->r, REG_RSP, valE);
sim->pc = valM;
break;
case I_PUSHQ: /* A:0 regA:F */
if(!NORM_REG(rA)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r, rA);
valB = get_reg_val(sim->r, REG_RSP);
valE = valB + (-8);
set_reg_val(sim->r, REG_RSP, valE);
if(!set_long_val(sim->m, valE, valA)){
err_print("PC = 0x%lx, Invalid stack address 0x%.8lx", sim->pc, valE);
return STAT_ADR;
}
sim->pc = next_pc;
break;
case I_POPQ: /* B:0 regA:F */
if(!NORM_REG(rA)){
err_print("PC = 0x%lx, Invalid register id %.2x", sim->pc, rArB);
return STAT_INS;
}
valA = get_reg_val(sim->r, REG_RSP);
valB = valA;
valE = valB + 8;
get_long_val(sim->m, valA, &valM);
set_reg_val(sim->r, REG_RSP, valE);
set_reg_val(sim->r, rA, valM);
sim->pc = next_pc;
break;
// return STAT_INS; /* unsupported now, replace it with your implementation */
default:
err_print("PC = 0x%lx, Invalid instruction %.2x", sim->pc, codefun);
return STAT_INS;
}
return STAT_AOK;
}
