genattrtab.c

早期freebsd实现

	{
	  attr = find_attr (XSTR (exp, 0), 0);
	  if (attr == NULL)
	    {
	      if (! strcmp (XSTR (exp, 0), "alternative"))
		{
		  XSTR (exp, 0) = alternative_name;
		  /* This can't be simplified any further.  */
		  RTX_UNCHANGING_P (exp) = 1;
		  return exp;
		}
	      else
		fatal ("Unknown attribute `%s' in EQ_ATTR", XEXP (exp, 0));
	    }

	  if (is_const && ! attr->is_const)
	    fatal ("Constant expression uses insn attribute `%s' in EQ_ATTR",
		   XEXP (exp, 0));

	  /* Copy this just to make it permanent,
	     so expressions using it can be permanent too.  */
	  exp = attr_eq (XSTR (exp, 0), XSTR (exp, 1));

	  /* It shouldn't be possible to simplify the value given to a
	     constant attribute, so don't expand this until it's time to
	     write the test expression.  */	       
	  if (attr->is_const)
	    RTX_UNCHANGING_P (exp) = 1;

	  if (attr->is_numeric)
	    {
	      for (p = XSTR (exp, 1); *p; p++)
		if (*p < '0' || *p > '9')
		   fatal ("Attribute `%s' takes only numeric values", 
			  XEXP (exp, 0));
	    }
	  else
	    {
	      for (av = attr->first_value; av; av = av->next)
		if (GET_CODE (av->value) == CONST_STRING
		    && ! strcmp (XSTR (exp, 1), XSTR (av->value, 0)))
		  break;

	      if (av == NULL)
		fatal ("Unknown value `%s' for `%s' attribute",
		       XEXP (exp, 1), XEXP (exp, 0));
	    }
	}
      else
	{
	  /* Make an IOR tree of the possible values.  */
	  orexp = false_rtx;
	  name_ptr = XSTR (exp, 1);
	  while ((p = next_comma_elt (&name_ptr)) != NULL)
	    {
	      newexp = attr_eq (XSTR (exp, 0), p);
	      orexp = insert_right_side (IOR, orexp, newexp, -2);
	    }

	  return check_attr_test (orexp, is_const);
	}
      break;

    case CONST_INT:
      /* Either TRUE or FALSE.  */
      if (XWINT (exp, 0))
	return true_rtx;
      else
	return false_rtx;

    case IOR:
    case AND:
      XEXP (exp, 0) = check_attr_test (XEXP (exp, 0), is_const);
      XEXP (exp, 1) = check_attr_test (XEXP (exp, 1), is_const);
      break;

    case NOT:
      XEXP (exp, 0) = check_attr_test (XEXP (exp, 0), is_const);
      break;

    case MATCH_OPERAND:
      if (is_const)
	fatal ("RTL operator \"%s\" not valid in constant attribute test",
	       GET_RTX_NAME (MATCH_OPERAND));
      /* These cases can't be simplified.  */
      RTX_UNCHANGING_P (exp) = 1;
      break;

    case LE:  case LT:  case GT:  case GE:
    case LEU: case LTU: case GTU: case GEU:
    case NE:  case EQ:
      if (GET_CODE (XEXP (exp, 0)) == SYMBOL_REF
	  && GET_CODE (XEXP (exp, 1)) == SYMBOL_REF)
	exp = attr_rtx (GET_CODE (exp),
			attr_rtx (SYMBOL_REF, XSTR (XEXP (exp, 0), 0)),
			attr_rtx (SYMBOL_REF, XSTR (XEXP (exp, 1), 0)));
      /* These cases can't be simplified.  */
      RTX_UNCHANGING_P (exp) = 1;
      break;

    case SYMBOL_REF:
      if (is_const)
	{
	  /* These cases are valid for constant attributes, but can't be
	     simplified.  */
	  exp = attr_rtx (SYMBOL_REF, XSTR (exp, 0));
	  RTX_UNCHANGING_P (exp) = 1;
	  break;
	}
    default:
      fatal ("RTL operator \"%s\" not valid in attribute test",
	     GET_RTX_NAME (GET_CODE (exp)));
    }

  return exp;
}

/* Given an expression, ensure that it is validly formed and that all named
   attribute values are valid for the given attribute.  Issue a fatal error
   if not.  If no attribute is specified, assume a numeric attribute.

   Return a perhaps modified replacement expression for the value.  */

static rtx
check_attr_value (exp, attr)
     rtx exp;
     struct attr_desc *attr;
{
  struct attr_value *av;
  char *p;
  int i;

  switch (GET_CODE (exp))
    {
    case CONST_INT:
      if (attr && ! attr->is_numeric)
	fatal ("CONST_INT not valid for non-numeric `%s' attribute",
	       attr->name);

      if (INTVAL (exp) < 0)
	fatal ("Negative numeric value specified for `%s' attribute",
	       attr->name);

      break;

    case CONST_STRING:
      if (! strcmp (XSTR (exp, 0), "*"))
	break;

      if (attr == 0 || attr->is_numeric)
	{
	  p = XSTR (exp, 0);
	  if (attr && attr->negative_ok && *p == '-')
	    p++;
	  for (; *p; p++)
	    if (*p > '9' || *p < '0')
	      fatal ("Non-numeric value for numeric `%s' attribute",
		     attr ? attr->name : "internal");
	  break;
	}

      for (av = attr->first_value; av; av = av->next)
	if (GET_CODE (av->value) == CONST_STRING
	    && ! strcmp (XSTR (av->value, 0), XSTR (exp, 0)))
	  break;

      if (av == NULL)
	fatal ("Unknown value `%s' for `%s' attribute",
	       XSTR (exp, 0), attr ? attr->name : "internal");

      break;

    case IF_THEN_ELSE:
      XEXP (exp, 0) = check_attr_test (XEXP (exp, 0),
				       attr ? attr->is_const : 0);
      XEXP (exp, 1) = check_attr_value (XEXP (exp, 1), attr);
      XEXP (exp, 2) = check_attr_value (XEXP (exp, 2), attr);
      break;

    case COND:
      if (XVECLEN (exp, 0) % 2 != 0)
	fatal ("First operand of COND must have even length");

      for (i = 0; i < XVECLEN (exp, 0); i += 2)
	{
	  XVECEXP (exp, 0, i) = check_attr_test (XVECEXP (exp, 0, i),
						 attr ? attr->is_const : 0);
	  XVECEXP (exp, 0, i + 1)
	    = check_attr_value (XVECEXP (exp, 0, i + 1), attr);
	}

      XEXP (exp, 1) = check_attr_value (XEXP (exp, 1), attr);
      break;

    case SYMBOL_REF:
      if (attr && attr->is_const)
	/* A constant SYMBOL_REF is valid as a constant attribute test and
	   is expanded later by make_canonical into a COND.  */
	return attr_rtx (SYMBOL_REF, XSTR (exp, 0));
      /* Otherwise, fall through... */

    default:
      fatal ("Illegal operation `%s' for attribute value",
	     GET_RTX_NAME (GET_CODE (exp)));
    }

  return exp;
}

/* Given an SET_ATTR_ALTERNATIVE expression, convert to the canonical SET.
   It becomes a COND with each test being (eq_attr "alternative "n") */

static rtx
convert_set_attr_alternative (exp, num_alt, insn_code, insn_index)
     rtx exp;
     int num_alt;
     int insn_code, insn_index;
{
  rtx condexp;
  int i;

  if (XVECLEN (exp, 1) != num_alt)
    fatal ("Bad number of entries in SET_ATTR_ALTERNATIVE for insn %d",
	   insn_index);

  /* Make a COND with all tests but the last.  Select the last value via the
     default.  */
  condexp = rtx_alloc (COND);
  XVEC (condexp, 0) = rtvec_alloc ((num_alt - 1) * 2);

  for (i = 0; i < num_alt - 1; i++)
    {
      char *p;
      p = attr_numeral (i);

      XVECEXP (condexp, 0, 2 * i) = attr_eq (alternative_name, p);
#if 0
      /* Sharing this EQ_ATTR rtl causes trouble.  */   
      XVECEXP (condexp, 0, 2 * i) = rtx_alloc (EQ_ATTR);
      XSTR (XVECEXP (condexp, 0, 2 * i), 0) = alternative_name;
      XSTR (XVECEXP (condexp, 0, 2 * i), 1) = p;
#endif
      XVECEXP (condexp, 0, 2 * i + 1) = XVECEXP (exp, 1, i);
    }

  XEXP (condexp, 1) = XVECEXP (exp, 1, i);

  return attr_rtx (SET, attr_rtx (ATTR, XSTR (exp, 0)), condexp);
}

/* Given a SET_ATTR, convert to the appropriate SET.  If a comma-separated
   list of values is given, convert to SET_ATTR_ALTERNATIVE first.  */

static rtx
convert_set_attr (exp, num_alt, insn_code, insn_index)
     rtx exp;
     int num_alt;
     int insn_code, insn_index;
{
  rtx newexp;
  char *name_ptr;
  char *p;
  int n;

  /* See how many alternative specified.  */
  n = n_comma_elts (XSTR (exp, 1));
  if (n == 1)
    return attr_rtx (SET,
		     attr_rtx (ATTR, XSTR (exp, 0)),
		     attr_rtx (CONST_STRING, XSTR (exp, 1)));

  newexp = rtx_alloc (SET_ATTR_ALTERNATIVE);
  XSTR (newexp, 0) = XSTR (exp, 0);
  XVEC (newexp, 1) = rtvec_alloc (n);

  /* Process each comma-separated name.  */
  name_ptr = XSTR (exp, 1);
  n = 0;
  while ((p = next_comma_elt (&name_ptr)) != NULL)
    XVECEXP (newexp, 1, n++) = attr_rtx (CONST_STRING, p);

  return convert_set_attr_alternative (newexp, num_alt, insn_code, insn_index);
}

/* Scan all definitions, checking for validity.  Also, convert any SET_ATTR
   and SET_ATTR_ALTERNATIVE expressions to the corresponding SET
   expressions. */

static void
check_defs ()
{
  struct insn_def *id;
  struct attr_desc *attr;
  int i;
  rtx value;

  for (id = defs; id; id = id->next)
    {
      if (XVEC (id->def, id->vec_idx) == NULL)
	continue;

      for (i = 0; i < XVECLEN (id->def, id->vec_idx); i++)
	{
	  value = XVECEXP (id->def, id->vec_idx, i);
	  switch (GET_CODE (value))
	    {
	    case SET:
	      if (GET_CODE (XEXP (value, 0)) != ATTR)
		fatal ("Bad attribute set in pattern %d", id->insn_index);
	      break;

	    case SET_ATTR_ALTERNATIVE:
	      value = convert_set_attr_alternative (value,
						    id->num_alternatives,
						    id->insn_code,
						    id->insn_index);
	      break;

	    case SET_ATTR:
	      value = convert_set_attr (value, id->num_alternatives,
					id->insn_code, id->insn_index);
	      break;

	    default:
	      fatal ("Invalid attribute code `%s' for pattern %d",
		     GET_RTX_NAME (GET_CODE (value)), id->insn_index);
	    }

	  if ((attr = find_attr (XSTR (XEXP (value, 0), 0), 0)) == NULL)
	    fatal ("Unknown attribute `%s' for pattern number %d",
		   XSTR (XEXP (value, 0), 0), id->insn_index);

	  XVECEXP (id->def, id->vec_idx, i) = value;
	  XEXP (value, 1) = check_attr_value (XEXP (value, 1), attr);
	}
    }
}

/* Given a constant SYMBOL_REF expression, convert to a COND that
   explicitly tests each enumerated value.  */

static rtx
convert_const_symbol_ref (exp, attr)
     rtx exp;
     struct attr_desc *attr;
{
  rtx condexp;
  struct attr_value *av;
  int i;
  int num_alt = 0;

  for (av = attr->first_value; av; av = av->next)
    num_alt++;

  /* Make a COND with all tests but the last, and in the original order.
     Select the last value via the default.  Note that the attr values
     are constructed in reverse order.  */

  condexp = rtx_alloc (COND);
  XVEC (condexp, 0) = rtvec_alloc ((num_alt - 1) * 2);
  av = attr->first_value;
  XEXP (condexp, 1) = av->value;

  for (i = num_alt - 2; av = av->next, i >= 0; i--)
    {
      char *p, *string;
      rtx value;

      string = p = (char *) oballoc (2
				     + strlen (attr->name)
				     + strlen (XSTR (av->value, 0)));
      strcpy (p, attr->name);
      strcat (p, "_");
      strcat (p, XSTR (av->value, 0));
      for (; *p != '\0'; p++)
	if (*p >= 'a' && *p <= 'z')
	  *p -= 'a' - 'A';

      value = attr_rtx (SYMBOL_REF, string);
      RTX_UNCHANGING_P (value) = 1;
      
      XVECEXP (condexp, 0, 2 * i) = attr_rtx (EQ, exp, value);

      XVECEXP (condexp, 0, 2 * i + 1) = av->value;
    }

  return condexp;
}

/* Given a valid expression for an attribute value, remove any IF_THEN_ELSE
   expressions by converting them into a COND.  This removes cases from this
   program.  Also, replace an attribute value of "*" with the default attribute
   value.  */

static rtx
make_canonical (attr, exp)
     struct attr_desc *attr;
     rtx exp;
{
  int i;
  rtx newexp;

  switch (GET_CODE (exp))
    {
    case CONST_INT:
      exp = make_numeric_value (INTVAL (exp));
      break;

    case CONST_STRING:
      if (! strcmp (XSTR (exp, 0), "*"))
	{
	  if (attr == 0 || attr->default_val == 0)
	    fatal ("(attr_value \"*\") used in invalid context.");
	  exp = attr->default_val->value;
	}

      break;

    case SYMBOL_REF:
      if (!attr->is_const || RTX_UNCHANGING_P (exp))
	break;
      /* The SYMBOL_REF is constant for a given run, so mark it as unchanging.
	 This makes the COND something that won't be considered an arbitrary
	 expression by walk_attr_value.  */
      RTX_UNCHANGING_P (exp) = 1;
      exp = convert_const_symbol_ref (exp, attr);
      RTX_UNCHANGING_P (exp) = 1;
      exp = check_attr_value (exp, attr);
      /* Goto COND case since this is now a COND.  Note that while the
         new expression is rescanned, all symbol_ref notes are mared as
	 unchanging.  */
      goto cond;

    case IF_THEN_ELSE:
      newexp = rtx_alloc (COND);
      XVEC (newexp, 0) = rtvec_alloc (2);
      XVECEXP (newexp, 0, 0) = XEXP (exp, 0);
      XVECEXP (newexp, 0, 1) = XEXP (exp, 1);

      XEXP (newexp, 1) = XEXP (exp, 2);