void opc_pop_handler(char *opd1,char *opd2,char *offset,char *immi){
int ans;
int dec_opd2=bintodec(opd2);
int val_esp=get_reg_val(8);
if(immi[1]=='0'){
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
int val_mem=get_mem_val(mem+val_esp);
ans=val_mem;
set_reg_val(regfile+dec_opd1,ans);
}
}
int new_esp=get_reg_val(8)+1;
set_reg_val(regfile+8,new_esp);
}
int greytodec(int* grey, int bits){
int* bin = greytobin(grey,bits);
int dec = bintodec(bin,bits);
free(bin);
return dec;
}
void opc_jmp_handler(char *opd1,char *opd2,char *offset,char *immi){
int ans;
int dec_opd2=bintodec(opd2);
if(immi[1]=='0'){
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
ans=get_reg_val(dec_opd1)-1;
set_reg_val(regfile+16,ans);
}
else{
int dec_im_opd1=bintodec(opd1);
ans=dec_im_opd1-1;
set_reg_val(regfile+16,ans);
}
}
pending_bds=2;
}
void opc_div_handler(char *opd1,char *opd2,char *offset,char *immi){
int ans;
int dec_opd2=bintodec(opd2);
if(immi[1]=='0'){
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
int val_eax=get_reg_val(0);
ans=val_eax/get_reg_val(dec_opd1);
set_reg_val(regfile+0,ans);
}
else{
int dec_im_opd1=bintodec(opd1);
ans=get_reg_val(0)/dec_im_opd1;
set_reg_val(regfile+0,ans);
}
}
}
void opc_push_handler(char *opd1,char *opd2,char *offset,char *immi){
int ans;
int dec_opd2=bintodec(opd2);
int val_esp=get_reg_val(8);
if(immi[1]=='0'){
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
ans=get_reg_val(dec_opd1);
set_reg_val(mem+val_esp,ans);
}
else{
int dec_im_opd1=bintodec(opd1);
ans=dec_im_opd1;
set_reg_val(mem+val_esp,ans);
}
}
int new_esp=get_reg_val(8)-1;
set_reg_val(regfile+8,new_esp);
}
// ----------------------------------------------------------------------------------------------------
int imm_to_dec(string imm) {
int n;
if (imm.substr(imm.size() - 1, imm.size() - 1).compare("h") == 0) { // hex
sscanf(imm.substr(0, imm.size() - 1).c_str(), "%x", &n);
return n;
} else if (imm.substr(imm.size() - 1, imm.size() - 1).compare("b") == 0) { // binary
return bintodec(atoi(imm.substr(0, imm.size() - 1).c_str()));
} else { // decimal
return atoi(imm.c_str());
}
}
void opc_cmp_handler(char *opd1,char *opd2,char *offset,char *immi){
int ans;
int dec_opd2=bintodec(opd2);
if(immi[1]=='0'){
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
int val_opd2=get_reg_val(dec_opd2);
ans=val_opd2-get_reg_val(dec_opd1);
}
else{
int dec_im_opd1=bintodec(opd1);
ans=get_reg_val(dec_opd2)-dec_im_opd1;
}
}
else{
int dec_off=bintodec(offset);
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
ans=get_mem_val(dec_opd2+dec_off)-get_reg_val(dec_opd1);
}
else{
int dec_im_opd1=bintodec(opd1);
ans=get_mem_val(dec_opd2+dec_off)-dec_im_opd1;
}
}
if(ans==0){
set_reg_val(regfile+R_FLAGS,0);
}
else if(ans>0){
set_reg_val(regfile+R_FLAGS,1);
}
else{
set_reg_val(regfile+R_FLAGS,2);
}
}
void execute(_decoder_output *decoded_instr){
instr_handlers[0]=opc_add_handler;
instr_handlers[1]=opc_sub_handler;
instr_handlers[2]=opc_mov_handler;
instr_handlers[3]=opc_and_handler;
instr_handlers[4]=opc_xor_handler;
instr_handlers[5]=opc_or_handler;
instr_handlers[6]=opc_cmp_handler;
instr_handlers[8]=opc_xchange_handler;
instr_handlers[9]=opc_push_handler;
instr_handlers[10]=opc_pop_handler;
instr_handlers[11]=opc_mul_handler;
instr_handlers[12]=opc_mul_handler;
instr_handlers[13]=opc_div_handler;
instr_handlers[14]=opc_div_handler;
instr_handlers[15]=opc_jmp_handler;
instr_handlers[16]=opc_je_handler;
instr_handlers[17]=opc_jne_handler;
instr_handlers[18]=opc_jg_handler;
instr_handlers[19]=opc_jge_handler;
instr_handlers[20]=opc_jl_handler;
instr_handlers[21]=opc_jle_handler;
instr_handlers[22]=opc_jmp_handler;
if(clock>2){
int dec_opc=bintodec(decoded_instr->opc);
if(dec_opc==63){
printf("\n\npc is %d\n",get_reg_val(15));
printf("\n\nregister file is\n");
print(regfile);
printf("\n\nmemory is\n");
print(mem);
printf("exiting");
exit(0);
}
instr_handlers[dec_opc](decoded_instr->opd1,decoded_instr->opd2,decoded_instr->offset,decoded_instr->immi);
}
switch(pending_bds){
case 2:
set_reg_val(regfile+REG_PC,get_reg_val(REG_PC)+1);
pending_bds--;
break;
case 1:
set_reg_val(regfile+REG_PC,get_reg_val(REG_NEXTPC)-2);
pending_bds--;
break;
case 0:
set_reg_val(regfile+REG_PC,get_reg_val(REG_PC)+1);
break;
}
}
void opc_xchange_handler(char *opd1,char *opd2,char *offset,char *immi){
int ans1,ans2;
int dec_opd2=bintodec(opd2);
if(immi[1]=='0'){
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
int val_opd2=get_reg_val(dec_opd2);
ans1=get_reg_val(dec_opd1);
set_reg_val(regfile+dec_opd2,ans1);
ans2=get_reg_val(dec_opd2);
set_reg_val(regfile+dec_opd1,ans2);
}
}
else{
int dec_off=bintodec(offset);
if(immi[0]=='0'){
int dec_opd1=bintodec(opd1);
ans1=get_mem_val(dec_opd2+dec_off)+get_reg_val(dec_opd1);
set_reg_val(mem+dec_opd2+dec_off,ans1);
ans2=get_mem_val(dec_opd2+dec_off);
set_reg_val(regfile+dec_opd1,ans2);
}
}
}
void decode()
{
flag3=0;
hextobin(instruction[0]);
strcpy(cond,arr);
hextobin(instruction[1]);
F[0]=arr[0];
F[1]=arr[1];
I=arr[2];
opcode[0]=arr[3];
b_opcode[0]=arr[2];
b_opcode[1]=arr[3];
hextobin(instruction[2]);
opcode[1]=arr[0];
opcode[2]=arr[1];
opcode[3]=arr[2];
b_offset[0]=arr[0];
b_offset[1]=arr[1];
b_offset[2]=arr[2];
S=arr[3];
b_offset[3]=arr[3];
hextobin(instruction[3]);
strcpy(Rn,arr);
b_offset[4]=arr[0];
b_offset[5]=arr[1];
b_offset[6]=arr[2];
b_offset[7]=arr[3];
hextobin(instruction[4]);
strcpy(Rd,arr);
b_offset[8]=arr[0];
b_offset[9]=arr[1];
b_offset[10]=arr[2];
b_offset[11]=arr[3];
hextobin(instruction[5]);
offset[0]=arr[0];
offset[1]=arr[1];
offset[2]=arr[2];
offset[3]=arr[3];
b_offset[12]=arr[0];
b_offset[13]=arr[1];
b_offset[14]=arr[2];
b_offset[15]=arr[3];
hextobin(instruction[6]);
Imm[0]=arr[0];
Imm[1]=arr[1];
Imm[2]=arr[2];
Imm[3]=arr[3];
offset[4]=arr[0];
offset[5]=arr[1];
offset[6]=arr[2];
offset[7]=arr[3];
b_offset[16]=arr[0];
b_offset[17]=arr[1];
b_offset[18]=arr[2];
b_offset[19]=arr[3];
hextobin(instruction[7]);
strcpy(Rm,arr);
offset[8]=arr[0];
offset[9]=arr[1];
offset[10]=arr[2];
offset[11]=arr[3];
b_offset[20]=arr[0];
b_offset[21]=arr[1];
b_offset[22]=arr[2];
b_offset[23]=arr[3];
Imm[4]=arr[0];
Imm[5]=arr[1];
Imm[6]=arr[2];
Imm[7]=arr[3];
sum=0;
bintodec(Rn);
n=sum;
sum=0;
bintodec(Rm);
mr=sum;
sum=0;
bintodec(Imm);
mi=sum;
sum=0;
bintodec(Rd);
d=sum;
sum=0;
bintodec(offset);
off=sum;
if(instruction[2]=='F')
{
flag3=1;
if(instruction[7]=='E')
b_off=-1;
if(instruction[7]=='D')
b_off=-2;
if(instruction[7]=='C')
b_off=-3;
if(instruction[7]=='B')
b_off=-4;
if(instruction[7]=='A')
b_off=-5;
if(instruction[7]=='9')
b_off=-6;
if(instruction[7]=='8')
b_off=-7;
if(instruction[7]=='7')
b_off=-8;
if(instruction[7]=='6')
b_off=-9;
if(instruction[7]=='5')
b_off=-10;
if(instruction[7]=='4')
b_off=-11;
if(instruction[7]=='3')
b_off=-12;
if(instruction[7]=='2')
b_off=-13;
if(instruction[7]=='1')
b_off=-14;
if(instruction[7]=='0')
b_off=-15;
}
else
{sum=0;
bintodec(b_offset);
b_off=sum;
}
//printf("\n f= %s b_opcode= %s, b_off = %d \n",F,b_opcode,b_off);
if((strcmp(F,"00")==0)&&(strcmp(opcode,"1101")==0) && I=='1')
{ printf(" Operation is MOV , immediate value is %d , Destination register is R%d \n",mi,d);
control=1;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"1101")==0) && I=='0')
{ printf(" Operation is MOV , register is R%d , Destination register is R%d \n",mr,d);
control=0;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='0'))
{
printf(" Operation is ADD , first operand is R%d ,Second operand is R%d , Destination register is R%d \n",n,mr,d);
control=2;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='1'))
{ //printreg();///////////////////////////
//u++; ////////////////////////
printf(" Operation is ADD , first operand is R%d ,immediate value is %d , Destination register is R%d \n",n,mi,d);
control=5;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0010")==0 )&&(I=='0'))
{
printf(" Operation is SUB , first operand is R%d ,Second operand is R%d , Destination register is R%d \n",n,mr,d);
control=6;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0010")==0 )&&(I=='1'))
{
printf(" Operation is SUB , first operand is R%d ,immediate value is %d , Destination register is R%d \n",n,mi,d);
control=7;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"1010")==0 )&&(I=='0'))
{
printf(" Operation is CMP , first operand is R%d ,Second operand is R%d \n",n,mr);
printf("\n R[4]== %d\n",R[4]);
control=9;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"1010")==0 )&&(I=='1'))
{
printf(" Operation is CMP , first operand is R%d ,immediate value is %d \n",n,mi);
printf("\n R[4]== %d\n",R[4]);
control=11;
if(z==0)
{w=mi;z=1;}
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='0'))
{
printf(" Operation is AND , first operand is R%d ,Second operand is R%d , Destination register is R%d \n",n,mr,d);
control=20;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='1'))
{
printf(" Operation is AND , first operand is R%d ,immediate value is %d , Destination register is R%d \n",n,mi,d);
control=21;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='0'))
{
printf(" Operation is OR , first operand is R%d ,Second operand is R%d , Destination register is R%d \n",n,mr,d);
control=22;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='1'))
{
printf(" Operation is OR , first operand is R%d ,immediate value is %d , Destination register is R%d \n",n,mi,d);
control=23;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='0'))
{
printf(" Operation is EOR , first operand is R%d ,Second operand is R%d , Destination register is R%d \n",n,mr,d);
control=24;
}
else
if((strcmp(F,"00")==0)&&(strcmp(opcode,"0100")==0 )&&(I=='1'))
{
printf(" Operation is EOR , first operand is R%d ,immediate value is %d , Destination register is R%d \n",n,mi,d);
control=25;
}
if((strcmp(F,"01")==0)&&(I=='0')&&(strcmp(opcode,"1100")==0))
{
printf(" Operation is LDR , base address is %d , offset is %d , Destination register is R%d \n",n,off,d);
control=3;
}
/*else
if((strcmp(F,"01")==0)&&(I=='0')&&(strcmp(opcode,"1100")==0)) //$$$$$$$$ for register offsets
{
printf(" Operation is LDR , base address is %d , offset is %d , Destination register is R%d \n",n,off,d);
control=26;
}
*/
else
if((strcmp(F,"01")==0)&&(I=='0')&&(strcmp(opcode,"1100")==0))
{
printf(" Operation is STR , base address is %d , offset is %d , register whose value is to be stored is R%d \n",n,off,d);
control=4;
}
else
if((strcmp(F,"01")==0)&&(I=='1')&&(strcmp(opcode,"1100")==0)) //$$$$$$$$$$ for register offsets
{
printf(" Operation is STR , base address is stored in R%d , offset register is R%d , register whose value is to be stored is R%d \n",n,mr,d);
control=27;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"0000")==0))
{
printf(" Operation is Branch EQ , branch offset is %d\n",b_off);
control=8;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"0001")==0))
{
printf(" Operation is Branch NE , branch offset is %d\n",b_off);
control=12;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"1011")==0))
{
printf(" Operation is Branch LT , branch offset is %d\n",b_off);
control=13;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"1101")==0))
{
printf(" Operation is Branch LE , branch offset is %d\n",b_off);
control=14;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"1100")==0))
{
printf(" Operation is Branch GT , branch offset is %d\n",b_off);
control=15;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"1010")==0))
{
printf(" Operation is Branch GE , branch offset is %d\n",b_off);
control=16;
}
else
if((strcmp(F,"10")==0)&&(strcmp(b_opcode,"10")==0)&&(strcmp(cond,"1110")==0))
{
//return; /////////////////////////////////////////////////////////////////////////
printf(" Operation is Branch ALL , branch offset is %d\n",b_off);
control=17;
}
else
if(strcmp(opcode,"1000")==0)
{ printf(" EXIT \n");
control=10;
}
/*else
if(instruction[4]=='5')
R[5]=
*/
}
