First/cpu.c

#include "simdata.h"
#include "cpu.h"
#include <stdlib.h>
#include <math.h>
#include <string.h>

/* Known errors:
 * 1) Exec does the calculations on the first clock cycle, there is a bug where in some cases exec isn't run on the last cycle and because of this the CPU still works.
 */


struct fetch_data_t *malloc_fetch_data(){
	struct fetch_data_t *ret=malloc(sizeof(struct fetch_data_t));
	ret->wait_for_exec=0;
	ret->exec_done=1;
	ret->decode_done=1;
	ret->fetch_wait=0;
	return ret;
}
void free_fetch_data(struct fetch_data_t *tofree){
	free(tofree);
}

int fetch(struct simdata_t *simdata){
	free_instr_list(&simdata->cpu_gui_hints->fetching_list);

	if(simdata->fetch_data->wait_for_exec!=0){
		simdata->fetch_data->fetch_wait=1;
		simdata->decode_data->valid=0;
		simdata->fetch_data->wait_for_exec=0;
		return 0;
	}
	if(simdata->fetch_data->fetch_wait){
		if(simdata->fetch_data->exec_done){
			simdata->fetch_data->fetch_wait=0;
		}else
			return 0;
	}
	if(!simdata->fetch_data->decode_done)
		return 0;

	simdata->decode_data->in_bytecode=(uint32_t)(simdata->RAM[simdata->registers->PC])<<24|(uint32_t)(simdata->RAM[simdata->registers->PC+1])<<16|(uint32_t)(simdata->RAM[simdata->registers->PC+2])<<8|(uint32_t)(simdata->RAM[simdata->registers->PC+3]);
	simdata->decode_data->valid=1;
	simdata->decode_data->address=simdata->registers->PC;
	add_to_instr_list(&simdata->cpu_gui_hints->fetching_list,simdata->registers->PC);
	simdata->registers->PC+=4;
	return 0;
}




struct decode_data_t *malloc_decode_data(){
	struct decode_data_t *ret=malloc(sizeof(struct decode_data_t));
	if(ret)
		ret->valid=0;
	ret->exec_done=1;
	return ret;
}
void free_decode_data(struct decode_data_t *tofree){
	free(tofree);
}
int decode(struct simdata_t *simdata){
	uint16_t opcode,op1,op2,imm;
	free_instr_list(&simdata->cpu_gui_hints->decoding_list);
	if(simdata->decode_data->exec_done==0){
		simdata->fetch_data->decode_done=0;
		return 0;
	}
	if(simdata->decode_data->valid==0){
		simdata->exec_data->valid=0;
		simdata->fetch_data->decode_done=1;
		return 0;
	}
	switch((simdata->decode_data->in_bytecode&0xE0000000)>>29){
		case 0:
			opcode=(simdata->decode_data->in_bytecode&0x1F000000)>>24;
			switch(opcode){
				case 0x00:
					simdata->exec_data->EXEC_ACTION=NOP;
					break;
				case 0x01:
				case 0x02:
				case 0x03:
				case 0x04:
				case 0x05:
				case 0x11:
				case 0x12:
				case 0x13:
				case 0x14:
				case 0x15:
					switch(opcode){
						case 0x01: case 0x11: simdata->exec_data->COND=COND_NONE; break;
						case 0x02: case 0x12: simdata->exec_data->COND=COND_ZERO; break;
						case 0x03: case 0x13: simdata->exec_data->COND=COND_NZERO; break;
						case 0x04: case 0x14: simdata->exec_data->COND=COND_CARRY; break;
						case 0x05: case 0x15: simdata->exec_data->COND=COND_NCARRY; break;
						default: return 1;
					}
					simdata->exec_data->out_op->OP_ADDR=IMMEDIATE;
					simdata->exec_data->out_op->data=simdata->decode_data->in_bytecode&0x00FFFFFF;
					simdata->exec_data->EXEC_ACTION=(opcode&0x10)?CALL:JUMP;
					simdata->fetch_data->wait_for_exec=1;
					break;
				case 0x0F:/* load SP */
					simdata->exec_data->EXEC_ACTION=MOVE;
					simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
					simdata->exec_data->in_op1->data=simdata->decode_data->in_bytecode&0x00FFFFFF;
					simdata->exec_data->out_op->OP_ADDR=REGISTER;
					simdata->exec_data->out_op->data=0xFF;
					break;
				case 0x10:
					simdata->exec_data->EXEC_ACTION=RET;
					simdata->fetch_data->wait_for_exec=1;
					break;
				default:
					return 1;
			}
			break;
		case 1:
			opcode=(simdata->decode_data->in_bytecode&0x1FFF0000)>>16;
			op1=(simdata->decode_data->in_bytecode&0x0000FF00)>>8;
			op2=(simdata->decode_data->in_bytecode&0x000000FF);


			simdata->exec_data->in_op1->data=op1;
			simdata->exec_data->in_op2->data=op2;
			switch(opcode){
				case 0x00:
				case 0x01:
				case 0x02:
				case 0x03:
				case 0x04:
				case 0x05:
				case 0x06:
				case 0x07:
				case 0x0A:
				case 0x0B:
				case 0x0C:
				case 0x0D:
				case 0x0E:
				case 0x0F:
				case 0x10:
				case 0x11:
				case 0x12:
					simdata->exec_data->in_op1->OP_ADDR=REGISTER;
					simdata->exec_data->in_op2->OP_ADDR=REGISTER;
					break;
				case 0x08:
					simdata->exec_data->in_op1->OP_ADDR=REGISTER;
					simdata->exec_data->in_op2->OP_ADDR=REGISTER_IND;
					break;
				case 0x09:
					simdata->exec_data->in_op1->OP_ADDR=REGISTER_IND;
					simdata->exec_data->in_op2->OP_ADDR=REGISTER;
					break;
			}

			switch(opcode){
				case 0x05:
					simdata->exec_data->EXEC_ACTION=HALT;
					break;
				case 0x06:
					simdata->exec_data->EXEC_ACTION=PUSH;
					break;
				case 0x07:
					simdata->exec_data->EXEC_ACTION=POP;
					break;
				case 0x08:
				case 0x09:
				case 0x12:
					simdata->exec_data->EXEC_ACTION=MOVE;
					break;
				default:
					simdata->exec_data->EXEC_ACTION=EXEC_ALU;
					break;
			}

			switch(opcode){
				case 0x00:
				case 0x01:
				case 0x04:
				case 0x0A:
				case 0x0B:
				case 0x0C:
				case 0x0D:
				case 0x12:
					simdata->exec_data->out_op->OP_ADDR=REGISTER;
					simdata->exec_data->out_op->data=op2;
					break;
				case 0x02:
				case 0x03:
				case 0x0E:
				case 0x0F:
				case 0x10:
				case 0x11:
					simdata->exec_data->out_op->OP_ADDR=REGISTER;
					simdata->exec_data->out_op->data=op1;
					break;
				case 0x08:
					simdata->exec_data->out_op->data=op2;
					simdata->exec_data->out_op->OP_ADDR=REGISTER_IND;
					break;
				case 0x09:
					simdata->exec_data->out_op->data=op2;
					simdata->exec_data->out_op->OP_ADDR=REGISTER;
					break;
			}


			switch(opcode){
				case 0x00: simdata->exec_data->ALU_OP=ALU_ADD;  break;
				case 0x01: simdata->exec_data->ALU_OP=ALU_SUB;  break;
				case 0x02: simdata->exec_data->ALU_OP=ALU_SL;  break;
				case 0x03: simdata->exec_data->ALU_OP=ALU_SR;  break;
				case 0x04: simdata->exec_data->ALU_OP=ALU_CMP;  break;
				case 0x05:
				case 0x06:
				case 0x07:
				case 0x08:
				case 0x09:
				case 0x12:
					break;
				case 0x0A: simdata->exec_data->ALU_OP=ALU_FDIV;  break;
				case 0x0B: simdata->exec_data->ALU_OP=ALU_FMUL;  break;
				case 0x0C: simdata->exec_data->ALU_OP=ALU_FADD;  break;
				case 0x0D: simdata->exec_data->ALU_OP=ALU_FSUB;  break;
				case 0x0E: simdata->exec_data->ALU_OP=ALU_FSIN;  break;
				case 0x0F: simdata->exec_data->ALU_OP=ALU_FCOS;  break;
				case 0x10: simdata->exec_data->ALU_OP=ALU_DEC;  break;
				case 0x11: simdata->exec_data->ALU_OP=ALU_INC;  break;
				default:
					return 1;
			}
			break;
		case 2:
			opcode=(simdata->decode_data->in_bytecode&0x1F000000)>>24;
			op1=(simdata->decode_data->in_bytecode&0x00FF0000)>>16;
			imm=(simdata->decode_data->in_bytecode&0x0000FFFF);
			switch(opcode){
				case 0:
					simdata->exec_data->EXEC_ACTION=MOVE;
					simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
					simdata->exec_data->in_op1->data=imm;

					simdata->exec_data->out_op->OP_ADDR=REGISTERL;
					simdata->exec_data->out_op->data=op1;
					break;
				case 1:
					simdata->exec_data->EXEC_ACTION=MOVE;
					simdata->exec_data->in_op1->OP_ADDR=IMMEDIATE;
					simdata->exec_data->in_op1->data=imm;

					simdata->exec_data->out_op->OP_ADDR=REGISTERH;
					simdata->exec_data->out_op->data=op1;
					break;
			}
			break;
		default:
			return 1;
	}
	simdata->fetch_data->decode_done=1;
	simdata->exec_data->valid=1;
	simdata->exec_data->address=simdata->decode_data->address;
	add_to_instr_list(&simdata->cpu_gui_hints->decoding_list,simdata->decode_data->address);
	return 0;
}




struct exec_data_t *malloc_exec_data(){
	struct exec_data_t *ret;
	ret=malloc(sizeof(struct exec_data_t));
	if(!ret)
		return 0;
	ret->in_op1=malloc(sizeof(struct exec_op_t));
	if(!ret->in_op1){
		free(ret);
		return 0;
	}
	ret->in_op2=malloc(sizeof(struct exec_op_t));
	if(!ret->in_op2){
		free(ret->in_op1);
		free(ret);
		return 0;
	}
	ret->out_op=malloc(sizeof(struct exec_op_t));
	if(!ret->out_op){
		free(ret->in_op1);
		free(ret->in_op2);
		free(ret);
		return 0;
	}
	ret->valid=0;
	ret->cycles_left=0;
	return ret;
}
void free_exec_data(struct exec_data_t *tofree){
	free(tofree->in_op1);
	free(tofree->in_op2);
	free(tofree->out_op);
	free(tofree);
}

#define RR_SIMPL_INDX	0
#define RR_COMPLX_INDX	1
#define RR_FCOMPLX_INDX	2
#define MEM_ACCS_INDX	3
#define IMM_LOAD_INDX	4
#define BRNCH_MISS_INDX	5
#define BRNCH_TAKN_INDX	6
#define BRNCH_UNCO_INDX	7
#define CALL_RET_INDX	8
#define RR_FTRI_INDX	9
#define RR_MOVE_INDX	10

int delay_values[]={
	1, // register-register (integer) add,sub,inc,dec,shift left/right float add,sub
	4, // register-register integer multiply, divide
	4, // register-register float multiply, divide
	2, // push / pop / read mem / write mem
	1, // immediate to register
	1, // branch not taken
	3, // branch taken
	3, // branch unconditional
	4, // call/ret
	4, // float sin/cos
	1  // register-register move
};


int exec(struct simdata_t *simdata){
	free_instr_list(&simdata->cpu_gui_hints->executing_list);
	if(simdata->exec_data->valid==1){
		simdata->fetch_data->exec_done=0;
		simdata->decode_data->exec_done=0;
	}
	if(simdata->exec_data->cycles_left==0){
		if(simdata->exec_data->valid==0)
			return 0;
		int condition=0;
		switch(simdata->exec_data->EXEC_ACTION){
			case CALL:
			case JUMP:
				switch(simdata->exec_data->COND){
					case COND_NONE:   condition=1;                              break;
					case COND_ZERO:   condition=simdata->registers->FLAGS&1;    break;
					case COND_NZERO:  condition=!(simdata->registers->FLAGS&1); break;
					case COND_CARRY:  condition=simdata->registers->FLAGS&2;    break;
					case COND_NCARRY: condition=!(simdata->registers->FLAGS&2); break;
				}
				switch(simdata->exec_data->COND){
					case COND_NONE:
						simdata->exec_data->cycles_left=delay_values[BRNCH_UNCO_INDX];
						break;
					default:
						if(condition)
							simdata->exec_data->cycles_left=delay_values[BRNCH_TAKN_INDX];
						else
							simdata->exec_data->cycles_left=delay_values[BRNCH_MISS_INDX];
						break;
				}
				if(condition){
					if(simdata->exec_data->EXEC_ACTION==CALL){
						*(uint32_t*)(simdata->RAM+simdata->registers->SP)=simdata->registers->PC;
						simdata->registers->SP+=4;
					}
					if(simdata->exec_data->out_op->OP_ADDR==IMMEDIATE)
						simdata->registers->PC=(uint32_t)(simdata->exec_data->out_op->data);
					else
						return 1;
				}
				break;
			case RET:
				simdata->exec_data->cycles_left=delay_values[CALL_RET_INDX];
				simdata->registers->SP-=4;
				simdata->registers->PC=simdata->RAM[simdata->registers->SP];
				break;
			case EXEC_ALU:
				if(	simdata->exec_data->in_op1->OP_ADDR==REGISTER &&
						simdata->exec_data->in_op2->OP_ADDR==REGISTER &&
						simdata->exec_data->out_op->OP_ADDR==REGISTER	){

					uint32_t result;
					switch(simdata->exec_data->ALU_OP){
						case ALU_ADD:
							result = simdata->registers->GPR[simdata->exec_data->in_op1->data] +
								simdata->registers->GPR[simdata->exec_data->in_op2->data];
							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
								(simdata->registers->GPR[simdata->exec_data->out_op->data] < simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						case ALU_SUB:
						case ALU_CMP:
							result = simdata->registers->GPR[simdata->exec_data->in_op2->data] -
								simdata->registers->GPR[simdata->exec_data->in_op1->data];
							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
								(simdata->registers->GPR[simdata->exec_data->out_op->data] > simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						case ALU_SL:
							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
								((simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x80000000)?2:0);
							result = simdata->registers->GPR[simdata->exec_data->in_op1->data]<<1;

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						case ALU_SR:
							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
								((simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x00000001)?2:0);
							result = simdata->registers->GPR[simdata->exec_data->in_op1->data]>>1;

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						case ALU_FDIV:
							result = ieee754_float_to_uint32(uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op2->data])/
								uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op1->data]));

							simdata->exec_data->cycles_left=delay_values[RR_COMPLX_INDX];

							break;
						case ALU_FMUL:
							result = ieee754_float_to_uint32(uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op1->data])*
								 uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op2->data]));

							simdata->exec_data->cycles_left=delay_values[RR_COMPLX_INDX];

							break;
						case ALU_FADD:
							result = ieee754_float_to_uint32(uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op2->data])+
								uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op1->data]));

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						case ALU_FSUB:
							result = ieee754_float_to_uint32(uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op2->data])-
								uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op1->data]));

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						case ALU_FSIN:
							result = ieee754_float_to_uint32(sinf(uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op1->data])));

							simdata->exec_data->cycles_left=delay_values[RR_FTRI_INDX];

							break;
						case ALU_FCOS:
							result = ieee754_float_to_uint32(cosf(uint32_to_ieee754_float(simdata->registers->GPR[simdata->exec_data->in_op1->data])));

							simdata->exec_data->cycles_left=delay_values[RR_FTRI_INDX];

							break;
						case ALU_DEC:
							*(uint32_t*)&result = *(uint32_t*)(&simdata->registers->GPR[simdata->exec_data->in_op1->data])-1;
							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
								(simdata->registers->GPR[simdata->exec_data->out_op->data] > simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;

							simdata->exec_data->cycles_left=delay_values[RR_FCOMPLX_INDX];

							break;
						case ALU_INC:
							*(uint32_t*)&result = *(uint32_t*)(&simdata->registers->GPR[simdata->exec_data->in_op1->data])+1;
							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
								(simdata->registers->GPR[simdata->exec_data->out_op->data] > simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;

							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];

							break;
						default:
							return 1;
					}
					simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFE)|(result==0);
					if(simdata->exec_data->ALU_OP!=ALU_CMP)
						simdata->registers->GPR[simdata->exec_data->out_op->data]=result;
				}else
					return 1;
				break;
			case MOVE:
				switch(simdata->exec_data->out_op->OP_ADDR){
					case REGISTERL:
						if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE){
							simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0xFFFF0000)|(0x0000FFFF&
								simdata->exec_data->in_op1->data);
							simdata->exec_data->cycles_left=delay_values[IMM_LOAD_INDX];
						}else{
							//simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0xFFFF0000)|(0x0000FFFF&
							//	simdata->registers->GPR[simdata->exec_data->in_op1->data]);
							//simdata->exec_data->cycles_left=
							return 1;
						}
						break;
					case REGISTERH:
						if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE){
							simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0x0000FFFF)|((0x0000FFFF&
								simdata->exec_data->in_op1->data)<<16);
							simdata->exec_data->cycles_left=delay_values[IMM_LOAD_INDX];
						}else{
							//simdata->registers->GPR[simdata->exec_data->out_op->data]=(simdata->registers->GPR[simdata->exec_data->out_op->data]&0x0000FFFF)|((0x0000FFFF&
							//	simdata->registers->GPR[simdata->exec_data->in_op1->data])<<16);
							//simdata->exec_data->cycles_left=
							return 1;
						}
						break;
					case REGISTER: /* This is for special registers like the SP which is 24bits long */
						if(simdata->exec_data->out_op->data==0xFF){
							if(simdata->exec_data->in_op1->OP_ADDR==IMMEDIATE){
								if( (simdata->exec_data->in_op1->data&0xFF000000) == 0 )
									simdata->registers->SP=simdata->exec_data->in_op1->data;
								else
									return 2;
								simdata->exec_data->cycles_left=delay_values[IMM_LOAD_INDX];
							}else if( simdata->exec_data->in_op1->OP_ADDR==REGISTER ){ /*for completeion, not valid ( yet )*/
								//if( (simdata->registers->GPR[simdata->exec_data->in_op1->data]&0xFF000000) == 0 )
								//	simdata->registers->SP=simdata->registers->GPR[simdata->exec_data->in_op1->data];
								//else
								//	return 2;
								return 1;
							}
						}else if(simdata->exec_data->in_op1->OP_ADDR==REGISTER_IND){
							if( (simdata->registers->GPR[simdata->exec_data->in_op1->data]&0xFF000000) == 0 ){
								simdata->registers->GPR[simdata->exec_data->out_op->data]=*(uint32_t*)(simdata->RAM+simdata->registers->GPR[simdata->exec_data->in_op1->data]);
								simdata->exec_data->cycles_left=delay_values[MEM_ACCS_INDX];
							}else
								return 2;
						}else if(simdata->exec_data->in_op1->OP_ADDR==REGISTER){
							simdata->registers->GPR[simdata->exec_data->out_op->data]=simdata->registers->GPR[simdata->exec_data->in_op1->data];

							simdata->exec_data->cycles_left=delay_values[RR_MOVE_INDX];
						}else
							return 1;
						break;
					case REGISTER_IND:
						if(simdata->exec_data->in_op1->OP_ADDR==REGISTER){
							*(uint32_t*)(simdata->RAM+(simdata->registers->GPR[simdata->exec_data->out_op->data]&0x00FFFFFF))=simdata->registers->GPR[simdata->exec_data->in_op1->data];
							if(simdata->registers->GPR[simdata->exec_data->out_op->data]==0x00FFFFFC)
								if(terminal_output(simdata->registers->GPR[simdata->exec_data->in_op1->data],simdata))
									return 1;

							simdata->exec_data->cycles_left=delay_values[MEM_ACCS_INDX];
						}else
							return 1;
						break;
					default:
						return 1;
				}
				break;
			case NOP:
				simdata->exec_data->cycles_left=1;
				break;
			case HALT:
				simdata->exec_data->cycles_left=1;
				simdata->cpu_state=CPU_HALTED;
				break;
			case PUSH:
				simdata->RAM[simdata->registers->SP  ]=simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x000000FF;
				simdata->RAM[simdata->registers->SP+1]=(simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x0000FF00)>>8;
				simdata->RAM[simdata->registers->SP+2]=(simdata->registers->GPR[simdata->exec_data->in_op1->data]&0x00FF0000)>>16;
				simdata->RAM[simdata->registers->SP+3]=(simdata->registers->GPR[simdata->exec_data->in_op1->data]&0xFF000000)>>24;
				simdata->registers->SP+=4;
				simdata->exec_data->cycles_left=delay_values[MEM_ACCS_INDX];
				break;
			case POP:
				simdata->registers->SP-=4;
				simdata->registers->GPR[simdata->exec_data->in_op1->data]=simdata->RAM[simdata->registers->SP];
				simdata->registers->GPR[simdata->exec_data->in_op1->data]|=simdata->RAM[simdata->registers->SP+1]<<8;
				simdata->registers->GPR[simdata->exec_data->in_op1->data]|=simdata->RAM[simdata->registers->SP+2]<<16;
				simdata->registers->GPR[simdata->exec_data->in_op1->data]|=simdata->RAM[simdata->registers->SP+3]<<24;
				simdata->exec_data->cycles_left=delay_values[MEM_ACCS_INDX];
				break;
		}
	}
	if(simdata->exec_data->cycles_left!=0)
		simdata->exec_data->cycles_left--;
	else
		return 1;//internal error
	if(simdata->exec_data->cycles_left==0){
		simdata->fetch_data->exec_done=1;
		simdata->decode_data->exec_done=1;
		simdata->finished_instructions++;
	}
	add_to_instr_list(&simdata->cpu_gui_hints->executing_list,simdata->exec_data->address);
	return 0;
}





int state=0;


/*
 * RETURN CODES:
 * 0 : success
 * 1 : error in execution stage
 * 2 : error in decode stage
 * 3 : error in fetch stage
 * 4 : internal error
 */
int cpu_cycle_clock(struct simdata_t *simdata){
	free_instr_list(&simdata->cpu_gui_hints->fetching_list);
	free_instr_list(&simdata->cpu_gui_hints->decoding_list);
	free_instr_list(&simdata->cpu_gui_hints->executing_list);
	switch(simdata->cpu_structure){
		case CPU_STRUCTURE_SIMPLE_PIPELINED:
			switch(exec(simdata)){
				case 0:  break;
				case 2:  return 4;
				default: return 1;
			}
			switch(decode(simdata)){
				case 0:  break;
				default: return 2;
			}
			switch(fetch(simdata)){
				case 0:  break;
				default: return 3;
			}
			break;
		case CPU_STRUCTURE_SIMPLE_NON_PIPELINED:
			switch(state){
				case 0:
					switch(fetch(simdata)){
						case 0:  break;
						default: return 3;
					}
					break;
				case 1:
					switch(decode(simdata)){
						case 0:  break;
						default: return 2;
					}
					break;
				case 2:
					switch(exec(simdata)){
						case 0:  break;
						case 2:  return 4;
						default: return 1;
					}
					break;
			}
			if(state==2){
				if(simdata->decode_data->exec_done)
					state=0;
			}else
				state++;
			break;
		default:
			return 4;

	}
	simdata->current_clock++;
	return 0;
}


int cpu_simdata_malloc(struct simdata_t *simdata){
	simdata->fetch_data=malloc_fetch_data();
	simdata->decode_data=malloc_decode_data();
	simdata->exec_data=malloc_exec_data();
	simdata->registers=malloc(sizeof(struct registers_t));
	simdata->registers->PC=0x00000000;
	simdata->registers->SP=0;
	if((simdata->fetch_data!=NULL)&&(simdata->decode_data!=NULL)&&(simdata->exec_data!=NULL))
		return 1;
	else
		return 0;
}

void cpu_simdata_free(struct simdata_t *simdata){
	free_fetch_data(simdata->fetch_data);
	free_decode_data(simdata->decode_data);
	free_exec_data(simdata->exec_data);
	free(simdata->registers);
}


char* EXEC_ACTION_t_to_string(enum EXEC_ACTION_t in){
	char* ret;
	switch(in){
		case EXEC_ALU: ret="EXEC_ALU"; break;
		case MOVE:     ret="MOVE";     break;
		case JUMP:     ret="JUMP";     break;
		case CALL:     ret="CALL";     break;
		case NOP:      ret="NOP";      break;
		case HALT:     ret="HALT";     break;
		case RET:      ret="RET";      break;
		case PUSH:     ret="PUSH";     break;
		case POP:      ret="POP";      break;
		default: ret="";
	}
	char *real_ret=malloc(9);
	*real_ret=0;
	strncpy(real_ret,ret,9);
	return real_ret;
}
char* ALU_OP_t_to_string(enum ALU_OP_t in){
	char* ret;
	switch(in){
		case ALU_ADD:  ret="LU_ADD";  break;
		case ALU_SUB:  ret="LU_SUB";  break;
		case ALU_SL:   ret="LU_SL";   break;
		case ALU_SR:   ret="LU_SR";   break;
		case ALU_CMP:  ret="LU_CMP";  break;
		case ALU_FDIV: ret="LU_FDIV"; break;
		case ALU_FMUL: ret="LU_FMUL"; break;
		case ALU_FADD: ret="LU_FADD"; break;
		case ALU_FSUB: ret="LU_FSUB"; break;
		case ALU_FSIN: ret="LU_FSIN"; break;
		case ALU_FCOS: ret="LU_FCOS"; break;
		case ALU_DEC:  ret="LU_DEC";  break;
		case ALU_INC:  ret="LU_INC";  break;
		default: ret="";
	}
	char *real_ret=malloc(8);
	*real_ret=0;
	strncpy(real_ret,ret,8);
	return real_ret;
}
char* COND_t_to_string(enum COND_t in){
	char* ret;
	switch(in){
		case COND_NONE:   ret="COND_NONE";   break;
		case COND_ZERO:   ret="COND_ZERO";   break;
		case COND_NZERO:  ret="COND_NZERO";  break;
		case COND_CARRY:  ret="COND_CARRY";  break;
		case COND_NCARRY: ret="COND_NCARRY"; break;
		default: ret="";
	}
	char *real_ret=malloc(12);
	*real_ret=0;
	strncpy(real_ret,ret,12);
	return real_ret;
}
char* OP_ADDR_t_to_string(enum OP_ADDR_t in){
	char* ret;
	switch(in){
		case IMMEDIATE:     ret="IMMEDIATE";     break;
		case REGISTER:      ret="REGISTER";      break;
		case REGISTERL:     ret="REGISTERL";     break;
		case REGISTERH:     ret="REGISTERH";     break;
		case REGISTER_IND:  ret="REGISTER_IND";  break;
		default: ret="";
	}
	char *real_ret=malloc(13);
	*real_ret=0;
	strncpy(real_ret,ret,13);
	return real_ret;
}