cpu.c
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//
// Created by imanol on 12/25/16.
//
#include <stdlib.h>
#include "cpu.h"
void mov(short dst, short src)
{
if(src > MAX_INT)
{
regs[dst] = regs[src % (MAX_INT+1)];
}
else
{
regs[dst] = src;
}
}
void push(short src)
{
if(src > MAX_INT)
{
stack_push(regs[src % (MAX_INT+1)]);
}
else
{
stack_push(src);
}
}
void pop(short dst)
{
short value = stack_pop();
if(STACK_FAULT)
{
fprintf(stderr,"CRITICAL: STACK VIOLATION\n");
core_dump();
}
regs[dst] = value;
}
void teq(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a == b);
}
void tgt(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a > b);
}
void jmp(short dst)
{
if(dst > MAX_INT)
{
pc = regs[dst % (MAX_INT+1)];
}
else
{
pc = dst;
}
}
void jnz(short cond, short dst)
{
if(cond)
{
jmp(dst);
}
}
void jz(short cond, short dst)
{
if(!cond)
{
jmp(dst);
}
}
void add(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a + b) % (MAX_INT+1);
}
void mult(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a * b) % (MAX_INT+1);
}
void mod(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a % b);
}
void and(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a & b);
}
void or(short dst, short a, short b)
{
if(a > MAX_INT)
{
a = regs[a % (MAX_INT+1)];
}
if(b > MAX_INT)
{
b = regs[b % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = (a | b);
}
void not(short dst, short src)
{
if(src > MAX_INT)
{
src = regs[src % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = ~src & 0x7FFF;
}
void load(short src, short dst)
{
if(src > MAX_INT)
{
src = regs[src % (MAX_INT+1)];
}
regs[dst % (MAX_INT+1)] = src;
}
void stor(short dst, short src)
{
if(src > MAX_INT)
{
src = regs[src % (MAX_INT+1)];
}
if(dst > MAX_INT)
{
mem[regs[dst % (MAX_INT+1)]] = src;
}
else
{
mem[dst] = src;
}
}
void call(short dst)
{
stack_push(pc);
jmp(dst);
}
uint8_t ret()
{
pc = stack_pop();
return STACK_FAULT;
}
void out(unsigned char a)
{
putchar(a);
}
void in(short dst)
{
int c = getchar();
regs[dst] = (short)c;
}
void nop()
{
return;
}
void start_execution()
{
for(;;)
{
short opcode = mem[pc++];
switch(opcode)
{
case HALT:
return;
case MOV:
mov(mem[pc],mem[pc+1]);
pc += 2;
break;
case PUSH:
push(mem[pc++]);
break;
case POP:
pop(mem[pc++]);
break;
case TEQ:
teq(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case TGT:
tgt(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case JMP:
jmp(mem[pc++]);
break;
case JNZ:
jnz(mem[pc],mem[pc+1]);
pc += 2;
break;
case JZ:
jz(mem[pc],mem[pc+1]);
pc += 2;
break;
case ADD:
add(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case MULT:
mult(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case MOD:
mod(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case AND:
and(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case OR:
or(mem[pc],mem[pc+1],mem[pc+2]);
pc += 3;
break;
case NOT:
not(mem[pc],mem[pc+1]);
pc += 2;
break;
case LOAD:
load(mem[pc],mem[pc+1]);
pc += 2;
break;
case STOR:
stor(mem[pc],mem[pc+1]);
pc += 2;
break;
case CALL:
call(mem[pc++]);
break;
case RET:
if(ret())
{
return;
}
break;
case OUT:
out((unsigned char)mem[pc++]);
break;
case IN:
in(mem[pc++]);
break;
case NOP:
nop();
break;
default:
fprintf(stderr,"CRITICAL: UNKNOWN OPCODE %2x FOUND IN %2x\n",opcode,pc);
core_dump();
break;
}
}
}
void core_dump()
{
fprintf(stderr,"r0: %2x\n",regs[0]);
fprintf(stderr,"r1: %2x\n",regs[1]);
fprintf(stderr,"r2: %2x\n",regs[2]);
fprintf(stderr,"r3: %2x\n",regs[3]);
fprintf(stderr,"r4: %2x\n",regs[4]);
fprintf(stderr,"r5: %2x\n",regs[5]);
fprintf(stderr,"r6: %2x\n",regs[6]);
fprintf(stderr,"r7: %2x\n",regs[7]);
fprintf(stderr,"pc: %2x\n",pc);
//dump memory to file
//dump stack to file
exit(1);
}