disassembler.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

  case sh_op:
  case sw_op:
  case sd_op:
  case swl_op:
  case swr_op:
  case lwl_op:
  case lwr_op:
  case ll_op:
  case sc_op:
    sprintf(bufptr, "%s\t%s,", op_name[i.i_format.opcode],
	    register_name(i.i_format.rt, regmask));
    do_loadstore = true;
    break;
    
  case ori_op:
  case xori_op:
    if (i.u_format.rs == ZERO) {
      sprintf(bufptr, "li\t%s,%d",
	      register_name(i.u_format.rt, regmask),
	      i.u_format.uimmediate);
      break;
    }
    /* fall through */
  case andi_op:
    sprintf(bufptr, "%s\t%s,%s,%#x", op_name[i.u_format.opcode],
	    register_name(i.u_format.rt, regmask),
	    register_name(i.u_format.rs, regmask),
	    i.u_format.uimmediate);
    break;
  case lui_op:
    sprintf(bufptr, "%s\t%s,%#x", op_name[i.u_format.opcode],
	    register_name(i.u_format.rt, regmask),
	    i.u_format.uimmediate);
    break;
  case addi_op:
  case addiu_op:
    if (i.i_format.rs == ZERO) {
      short sign_extender = i.i_format.simmediate;
      sprintf(bufptr, "li\t%s,%d",
	      register_name(i.i_format.rt, regmask),
	      sign_extender);
      break;
    }
    /* fall through */
  default:
    {
      short sign_extender = i.i_format.simmediate;
      sprintf(bufptr, "%s\t%s,%s,%d", op_name[i.i_format.opcode],
	      register_name(i.i_format.rt, regmask),
	      register_name(i.i_format.rs, regmask),
	      sign_extender);
    }
    break;

  case cop0_op:
    switch (i.r_format.rs) {
    case bc_op:
      sprintf(bufptr, "bc0%s\t", bc_name[i.i_format.rt]);
      do_b_displacement = true;
      break;
    case mtc_op:
      sprintf(bufptr, "mtc0\t%s,%s",
	      register_name(i.r_format.rt, regmask),
	      c0_register_name(i.r_format.rd));
      break;
    case mfc_op:
      sprintf(bufptr, "mfc0\t%s,%s",
	      register_name(i.r_format.rt, regmask),
	      c0_register_name(i.r_format.rd));
      break;
    case cfc_op:
      sprintf(bufptr, "cfc0\t%s,$%d",
	      register_name(i.r_format.rt, regmask),
	      i.r_format.rd);
      break;
    case ctc_op:
      sprintf(bufptr, "ctc0\t%s,$%d",
	      register_name(i.r_format.rt, regmask),
	      i.r_format.rd);
      break;
    case cop_op:
      sprintf(bufptr, "c0\t%s", c0func_name[i.r_format.func]);
      break;
    default:
      sprintf(bufptr, "c0rs%d", i.r_format.rs);
      break;
    }
    break;
    
  case cop1_op:
    switch (i.r_format.rs) {
    case bc_op:
      sprintf(bufptr, "bc1%s\t", bc_name[i.i_format.rt]);
      do_b_displacement = true;
      break;
    case mtc_op:
      sprintf(bufptr, "mtc1\t%s,%s",
	      register_name(i.r_format.rt, regmask),
	      fp_register_name(i.r_format.rd));
      break;
    case mfc_op:
      sprintf(bufptr, "mfc1\t%s,%s",
	      register_name(i.r_format.rt, regmask),
	      fp_register_name(i.r_format.rd));
      break;
    case cfc_op:
      sprintf(bufptr, "cfc1\t%s,$%d",
	      register_name(i.r_format.rt, regmask),
	      i.r_format.rd);
      break;
    case ctc_op:
      sprintf(bufptr, "ctc1\t%s,$%d",
	      register_name(i.r_format.rt, regmask),
	      i.r_format.rd);
      break;
    case cop_op+s_fmt:
    case cop_op+d_fmt:
    case cop_op+e_fmt:
    case cop_op+w_fmt:
      sprintf(bufptr, "%s.%s\t",
	      cop1func_name[i.r_format.func],
	      c1fmt_name[i.r_format.rs - cop_op]);
      bufptr += strlen(bufptr);
      switch (i.r_format.func) {
      case fsqrt_op:
      case fabs_op:
      case fmov_op:
      case fcvts_op:
      case fcvtd_op:
      case fcvte_op:
      case fcvtw_op:
      case ftrunc_op:
      case fround_op:
      case ffloor_op:
      case fceil_op:
	sprintf(bufptr, "%s,%s",
		fp_register_name(i.r_format.re),
		fp_register_name(i.r_format.rd));
	break;
      case fcmp_op+0x0:
      case fcmp_op+0x1:
      case fcmp_op+0x2:
      case fcmp_op+0x3:
      case fcmp_op+0x4:
      case fcmp_op+0x5:
      case fcmp_op+0x6:
      case fcmp_op+0x7:
      case fcmp_op+0x8:
      case fcmp_op+0x9:
      case fcmp_op+0xa:
      case fcmp_op+0xb:
      case fcmp_op+0xc:
      case fcmp_op+0xd:
      case fcmp_op+0xe:
      case fcmp_op+0xf:
	sprintf(bufptr, "%s,%s",
		fp_register_name(i.r_format.rd),
		fp_register_name(i.r_format.rt));
	break;
      default:
	sprintf(bufptr, "%s,%s,%s",
		fp_register_name(i.r_format.re),
		fp_register_name(i.r_format.rd),
		fp_register_name(i.r_format.rt));
	break;
      } /* switch on func */
    } /* switch on rs */
    break; /* End of cop1 */
    
  case cop2_op:
  case cop3_op:
    {
      unsigned which_cop = i.j_format.opcode - cop0_op;
      
      switch (i.r_format.rs) {
      case bc_op:
	sprintf(bufptr, "bc%d%c\t", which_cop,
		bc_name[i.r_format.rt]);
	do_b_displacement = true;
	break;
      case mtc_op:
	sprintf(bufptr, "mtc%d\t%s,$%d", which_cop,
		register_name(i.r_format.rt, regmask),
		i.r_format.rd);
	break;
      case mfc_op:
	sprintf(bufptr, "mfc%d\t%s,$%d", which_cop,
		register_name(i.r_format.rt, regmask),
		i.r_format.rd);
	break;
      case cfc_op:
	sprintf(bufptr, "cfc%d\t%s,$%d", which_cop,
		register_name(i.r_format.rt, regmask),
		i.r_format.rd);
	break;
      case ctc_op:
	sprintf(bufptr, "ctc%d\t%s,$%d", which_cop,
		register_name(i.r_format.rt, regmask),
		i.r_format.rd);
	break;
      default:
	sprintf(bufptr, "c%d.%d\t%d", which_cop, i.r_format.rs, i.r_format.func);
	break;
      }
    }
    break;
    
  }
  
  /* Some instructions require more than just registers */
  
  if (do_loadstore) {
    short sign_extender = i.i_format.simmediate;
    *symbol_value = sign_extender;
    *ls_register = i.i_format.rs;
    bufptr += strlen(bufptr);
    sprintf(bufptr, "%d(%s)", sign_extender,
	    register_name(i.i_format.rs, regmask));
    return_value = -1;
  }
  else if (do_b_displacement) {
    short sign_extender = i.i_format.simmediate;
    bufptr += strlen(bufptr);
    sprintf(bufptr, "%#x", address+4+(sign_extender<<2));
    return_value = 2;
  }
  
  return return_value;
}

/* public - see .h file */
void
dis_regs(buffer, regmask, reg_values)
  char *buffer;
  unsigned regmask;
  unsigned reg_values[];
  {
  boolean first = true;
  unsigned i;

  buffer += strlen(buffer);
  for (i = 0; regmask; i++, regmask >>= 1)
    {
    if (regmask & 1)
      {
      sprintf(buffer, "%s%s=%#x",
	first ? "\t<" : ",",
	save.reg_names[i],
	reg_values[i]);
      buffer += strlen(buffer);
      first = false;
      }
    }
  if (!first)
    strcat(buffer, ">");
  }

#include <errno.h>
extern int errno;

/* public - see .h file */
int
disassembler(iadr, regstyle, get_symname, get_regvalue, get_bytes, print_header)
  unsigned iadr;
  int regstyle;
  char *(*get_symname)();
  int (*get_regvalue)();
  long (*get_bytes)();
  void (*print_header)();
  {
  unsigned old_iadr = iadr;

  if (!get_bytes)
    {
    errno = EINVAL;
    return -1;
    }

  /* Don't print address, value, or (if we have get_symname) jal targets */
  dis_init("", "", regstyle ? HARDWARE_NAMES : COMPILER_NAMES,
    ! (int) get_symname);

  for (; ; iadr += 4)
    {
    int which;
    unsigned instr, regmask, symbol_value, ls_register;
    char buffer[1024], *symname;

    instr = (unsigned) get_bytes();
    if (print_header)
      print_header(iadr, instr);
    which = disasm(buffer, iadr, instr, &regmask, &symbol_value, &ls_register);

    /* For jal, must print the target either via get_symname or numerically */
    if ((which == 1) && get_symname)
      if (symname = get_symname(symbol_value))
	strcat(buffer, symname);
      else
	sprintf(buffer + strlen(buffer), "%#x", symbol_value);

    /* For load/store, if we have get_regvalue, must print the effective addr */
    else if ((which < 0) && get_regvalue)
      sprintf(buffer + strlen(buffer),
	" <0x%x>", get_regvalue(ls_register) + symbol_value);

    /* If we have get_regvalue, we must print the registers */
    if (regmask && get_regvalue)
      {
      unsigned reg_values[32], reg_cnt, regtemp;

      for (reg_cnt = 0, regtemp = regmask; regtemp; reg_cnt++, regtemp >>= 1)
	if (regtemp & 1)
	  reg_values[reg_cnt] = get_regvalue(reg_cnt);
      dis_regs(buffer + strlen(buffer), regmask, reg_values);
      }

    puts(buffer);

    /* Quit unless we have a jump/call/branch delay slot */
    if (which <= 0)
      return iadr - old_iadr + 4;
    }
  }