alu-main.c

/*
  alu-main.c
  bho1 2006; bho1 19.11.2006; bho1 8.12.2007
  bho1 29.11.2007 : init value for rega, regb, accu. flags to full 16 Bit
  bho1 19.11.2009 : corrected error with neg_b calling neg_a
  bho1 10.12.2009 : corrected error where neg_b and not_b loaded arg into rega
  bho1 5.7.2011
  renamed alu_exec_line to alu_parse_line
  bho1 10.10.2011
  functional appoach: alu(ALU_OP_CODE, rega, regb, accumulator, flags);
  bho1 20.9.2014 cleaned

  GPL

*/

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "register.h"
#include "flags.h"
#include "alu-opcodes.h"
#include "alu.h"

// the registers
char rega[REG_WIDTH+1] = "01234567";
char regb[REG_WIDTH+1] = "01234567";
char accumulator[REG_WIDTH+1] = "01234567";
char flags[REG_WIDTH+1] = "01234567";


/*
  take string cmd_line, parse the line and call the alu function
  corresponding to alu-opcodes.h
*/
void alu_parse_line(char *cmd_line){
  char opcode[100];
  char operand1[100];
  char operand2[100];
  int nargs = 0;
  
  nargs = sscanf (cmd_line, "%s %s %s", opcode, operand1, operand2);
  
  switch(nargs){
  case 3:
    ldhex2register(operand1, rega);
    ldhex2register(operand2, regb);
    if(!strcmp(opcode,"add")){
      alu(ALU_OP_ADD, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"adc"))
      alu(ALU_OP_ADC, rega, regb, accumulator, flags);
    if(!strcmp(opcode,"sub"))
      alu(ALU_OP_SUB, rega, regb, accumulator, flags);
    if(!strcmp(opcode,"sbc"))
      alu(ALU_OP_SBC, rega, regb, accumulator, flags);
    if(!strcmp(opcode,"and"))
      alu(ALU_OP_AND, rega, regb, accumulator, flags);
    if(!strcmp(opcode,"or"))
      alu(ALU_OP_OR, rega, regb, accumulator, flags);
    if(!strcmp(opcode,"xor"))
      alu(ALU_OP_XOR, rega, regb, accumulator, flags);
    printf("%s %s %s\n", opcode, operand1, operand2);
    break;
  case 2:
    if(!strcmp(opcode,"ror")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_ROR, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"rol")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_ROL, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"asl")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_ASL, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"lsr")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_LSR, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"neg")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_NEG, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"not")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_NOT, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"inc")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_INC, rega, regb, accumulator, flags);
    }
    if(!strcmp(opcode,"dec")){
      ldhex2register(operand1, rega);
      alu(ALU_OP_DEC, rega, regb, accumulator, flags);
    }
    printf("%s %s\n", opcode, operand1);
    break;
  case 1:
    if(!strcmp(opcode,"reset")){
      alu(ALU_OP_RESET, rega, regb, accumulator, flags);
      //      alu_main_reset(rega, regb, accumulator, flags);
      printf("%s\n", opcode);
      break;
    }
    if(!strcmp(opcode,"clc")){
      flags[CFLAG] = '0';
      printf("%s\n", opcode);
      break;
    }
    if(!strcmp(opcode,"sec")){
      flags[CFLAG] = '1';
      printf("%s\n", opcode);
      break;
    }
    break;
  }
}


void print_alu(char *rega, char *regb, char * accumulator, char flags[])
{
  int sa,sb,sacc, a,b,acc;

  a = conv_bitstr2int(rega, 0, 7);
  b = conv_bitstr2int(regb, 0, 7);
  acc = conv_bitstr2int(accumulator, 0, 7);

  sa = s2int(rega);
  sb = s2int(regb);
  sacc = s2int(accumulator);

  printf("              binary     signed decimal  unsiged decimal\n");

  printf("Register A    %s       % 4i              % 4i\n",rega, sa, a);

  printf("Register B    %s       % 4i              % 4i\n",regb, sb, b);

  printf("accumulator   %s       % 4i              % 4i\n",accumulator, sacc, acc);

  printf("CSZO\n");
  printf("%c%c%c%c\n", flags[CFLAG], flags[SFLAG], flags[ZFLAG], flags[OFLAG]);
  printf("***********************\n");
}

int main()
{

  size_t nbytes = 80;
  char *cmd_line = (char *) malloc (nbytes + 1);  

  /*
	read line from stdio, parse line, execute line, print result
  */
  
  while(getline(&cmd_line, &nbytes, stdin) != -1) {
    alu_parse_line(cmd_line);
    print_alu(rega, regb, accumulator, flags);	
  }
  
  return 1 ;

}