Exemple #1
0
Fichier : rtl.c Projet : keparo/gcc
rtx
copy_rtx (rtx orig)
{
  rtx copy;
  int i, j;
  RTX_CODE code;
  const char *format_ptr;

  code = GET_CODE (orig);

  switch (code)
    {
    case REG:
    case DEBUG_EXPR:
    case VALUE:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_FIXED:
    case CONST_VECTOR:
    case SYMBOL_REF:
    case CODE_LABEL:
    case PC:
    case CC0:
    case RETURN:
    case SIMPLE_RETURN:
    case SCRATCH:
      /* SCRATCH must be shared because they represent distinct values.  */
      return orig;
    case CLOBBER:
      if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
	return orig;
      break;

    case CONST:
      if (shared_const_p (orig))
	return orig;
      break;

      /* A MEM with a constant address is not sharable.  The problem is that
	 the constant address may need to be reloaded.  If the mem is shared,
	 then reloading one copy of this mem will cause all copies to appear
	 to have been reloaded.  */

    default:
      break;
    }

  /* Copy the various flags, fields, and other information.  We assume
     that all fields need copying, and then clear the fields that should
     not be copied.  That is the sensible default behavior, and forces
     us to explicitly document why we are *not* copying a flag.  */
  copy = shallow_copy_rtx (orig);

  /* We do not copy the USED flag, which is used as a mark bit during
     walks over the RTL.  */
  RTX_FLAG (copy, used) = 0;

  format_ptr = GET_RTX_FORMAT (GET_CODE (copy));

  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
    switch (*format_ptr++)
      {
      case 'e':
	if (XEXP (orig, i) != NULL)
	  XEXP (copy, i) = copy_rtx (XEXP (orig, i));
	break;

      case 'E':
      case 'V':
	if (XVEC (orig, i) != NULL)
	  {
	    XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
	    for (j = 0; j < XVECLEN (copy, i); j++)
	      XVECEXP (copy, i, j) = copy_rtx (XVECEXP (orig, i, j));
	  }
	break;

      case 't':
      case 'w':
      case 'i':
      case 's':
      case 'S':
      case 'T':
      case 'u':
      case 'B':
      case '0':
	/* These are left unchanged.  */
	break;

      default:
	gcc_unreachable ();
      }
  return copy;
}
Exemple #2
0
rtx
copy_rtx (rtx orig)
{
  rtx copy;
  int i, j;
  RTX_CODE code;
  const char *format_ptr;

  code = GET_CODE (orig);

  switch (code)
    {
    case REG:
    case DEBUG_EXPR:
    case VALUE:
    CASE_CONST_ANY:
    case SYMBOL_REF:
    case CODE_LABEL:
    case PC:
    case CC0:
    case RETURN:
    case SIMPLE_RETURN:
    case SCRATCH:
      /* SCRATCH must be shared because they represent distinct values.  */
      return orig;
    case CLOBBER:
      /* Share clobbers of hard registers (like cc0), but do not share pseudo reg
         clobbers or clobbers of hard registers that originated as pseudos.
         This is needed to allow safe register renaming.  */
      if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER
	  && ORIGINAL_REGNO (XEXP (orig, 0)) == REGNO (XEXP (orig, 0)))
	return orig;
      break;

    case CLOBBER_HIGH:
	gcc_assert (REG_P (XEXP (orig, 0)));
	return orig;

    case CONST:
      if (shared_const_p (orig))
	return orig;
      break;

      /* A MEM with a constant address is not sharable.  The problem is that
	 the constant address may need to be reloaded.  If the mem is shared,
	 then reloading one copy of this mem will cause all copies to appear
	 to have been reloaded.  */

    default:
      break;
    }

  /* Copy the various flags, fields, and other information.  We assume
     that all fields need copying, and then clear the fields that should
     not be copied.  That is the sensible default behavior, and forces
     us to explicitly document why we are *not* copying a flag.  */
  copy = shallow_copy_rtx (orig);

  format_ptr = GET_RTX_FORMAT (GET_CODE (copy));

  for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
    switch (*format_ptr++)
      {
      case 'e':
	if (XEXP (orig, i) != NULL)
	  XEXP (copy, i) = copy_rtx (XEXP (orig, i));
	break;

      case 'E':
      case 'V':
	if (XVEC (orig, i) != NULL)
	  {
	    XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
	    for (j = 0; j < XVECLEN (copy, i); j++)
	      XVECEXP (copy, i, j) = copy_rtx (XVECEXP (orig, i, j));
	  }
	break;

      case 't':
      case 'w':
      case 'i':
      case 'p':
      case 's':
      case 'S':
      case 'T':
      case 'u':
      case 'B':
      case '0':
	/* These are left unchanged.  */
	break;

      default:
	gcc_unreachable ();
      }
  return copy;
}