r16/emu/cpu/instruction.c

#include "./instruction.h"
#include <stdio.h>
#include <stdlib.h>

r16_int GetArgVal(ArgumentInfo argInfo, r16_int arg)
{
    switch (argInfo)
    {
        case value:
            return arg;
        case valueInRegister:
            return GetRegister((CpuRegisters)arg.u);
        case valueInRam:
            return GetValue(arg);
        case pointerInRegister:
            return GetValue(GetRegister((CpuRegisters)arg.u));
    }
}

void GetAllArgVal(ArgumentInfo arg1Info, ArgumentInfo arg2Info, 
                    r16_int arg1, r16_int arg2, 
                    r16_int *arg1Out, r16_int *arg2Out)
{
    *arg1Out = GetArgVal(arg1Info, arg1);
    *arg2Out = GetArgVal(arg2Info, arg2);
}

void ExecuteInstruction(CpuInstructions instruction, ArgumentInfo arg1Info,
                        ArgumentInfo arg2Info, r16_int arg1, r16_int arg2)
{
    r16_int actArg1, actArg2;

    switch (instruction)
    {
        case HLT:
            printf("\nprogram HALTED!\n");
            exit(0);
        case ADD:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.s + actArg2.s });
            break;
        case SUB:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.s - actArg2.s });
            break;
        case MUL:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.s * actArg2.s });
            break;
        case DIV:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.s / actArg2.s });
            break;
        case LBS:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.s << actArg2.s });
            break;
        case RBS:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.s >> actArg2.s });
            break;
        case BAN:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.u & actArg2.u });
            break;
        case BOR:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.u | actArg2.u });
            break;
        case BXO:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetRegister(ACU, (r16_int){ actArg1.u ^ actArg2.u });
            break;
        case BNO:
            SetRegister(ACU, (r16_int){ ~ GetArgVal(arg1Info, arg1).u });
            break;
        case PUS:
            StackPush(GetArgVal(arg1Info, arg1));
            break;
        case POP:
            SetRegister(ACU, StackPop());
            break;
        case JMP:
            SetRegister(PC, GetArgVal(arg1Info, arg1));
            break;
        case JEQ:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            if (actArg2.u == GetRegister(ACU).u)
                SetRegister(PC, actArg1);
            break;
        case JNZ:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            if (actArg2.s != 0)
                SetRegister(PC, actArg1);
            break;
        case CAL:
            StackPush(GetRegister(PC));
            SetRegister(PC, GetArgVal(arg1Info, arg1));
            break;
        case RET:
            SetRegister(PC, StackPop());
            break;
        case REG: // TODO
        case INT: // TODO
            fprintf(stderr, "INTS NOT IMPLEMENTED YET\n");
            exit(-1);
        case INP:
            SetRegister(ACU, (r16_int){ getchar() });
            break;
        case OUT:
            putchar((char)(GetArgVal(arg1Info, arg1).u));
            break;
        case DIN: // TODO
        case DOT: // TODO
            fprintf(stderr, "DISK NOT IMPLEMENTED YET\n");
            exit(-1);
        case MOV:
            GetAllArgVal(arg1Info, arg2Info, arg1, arg2, &actArg1, &actArg2);
            SetValue(actArg1, actArg2);
            break;
    }
}