genattrtab.c

早期freebsd实现

/* Add an entry to the hash table for STRING with hash code HASHCODE.  */

static void
attr_hash_add_string (hashcode, str)
     int hashcode;
     char *str;
{
  register struct attr_hash *h;

  h = (struct attr_hash *) obstack_alloc (hash_obstack,
					  sizeof (struct attr_hash));
  h->hashcode = -hashcode;
  h->u.str = str;
  h->next = attr_hash_table[hashcode % RTL_HASH_SIZE];
  attr_hash_table[hashcode % RTL_HASH_SIZE] = h;
}

/* Generate an RTL expression, but avoid duplicates.
   Set the RTX_INTEGRATED_P flag for these permanent objects.

   In some cases we cannot uniquify; then we return an ordinary
   impermanent rtx with RTX_INTEGRATED_P clear.

   Args are like gen_rtx, but without the mode:

   rtx attr_rtx (code, [element1, ..., elementn])  */

/*VARARGS1*/
static rtx
attr_rtx (va_alist)
     va_dcl
{
  va_list p;
  enum rtx_code code;
  register int i;		/* Array indices...			*/
  register char *fmt;		/* Current rtx's format...		*/
  register rtx rt_val;		/* RTX to return to caller...		*/
  int hashcode;
  register struct attr_hash *h;
  struct obstack *old_obstack = rtl_obstack;

  va_start (p);
  code = va_arg (p, enum rtx_code);

  /* For each of several cases, search the hash table for an existing entry.
     Use that entry if one is found; otherwise create a new RTL and add it
     to the table.  */

  if (GET_RTX_CLASS (code) == '1')
    {
      rtx arg0 = va_arg (p, rtx);

      /* A permanent object cannot point to impermanent ones.  */
      if (! RTX_INTEGRATED_P (arg0))
	{
	  rt_val = rtx_alloc (code);
	  XEXP (rt_val, 0) = arg0;
	  va_end (p);
	  return rt_val;
	}

      hashcode = ((HOST_WIDE_INT) code + RTL_HASH (arg0));
      for (h = attr_hash_table[hashcode % RTL_HASH_SIZE]; h; h = h->next)
	if (h->hashcode == hashcode
	    && GET_CODE (h->u.rtl) == code
	    && XEXP (h->u.rtl, 0) == arg0)
	  goto found;

      if (h == 0)
	{
	  rtl_obstack = hash_obstack;
	  rt_val = rtx_alloc (code);
	  XEXP (rt_val, 0) = arg0;
	}
    }
  else if (GET_RTX_CLASS (code) == 'c'
	   || GET_RTX_CLASS (code) == '2'
	   || GET_RTX_CLASS (code) == '<')
    {
      rtx arg0 = va_arg (p, rtx);
      rtx arg1 = va_arg (p, rtx);

      /* A permanent object cannot point to impermanent ones.  */
      if (! RTX_INTEGRATED_P (arg0) || ! RTX_INTEGRATED_P (arg1))
	{
	  rt_val = rtx_alloc (code);
	  XEXP (rt_val, 0) = arg0;
	  XEXP (rt_val, 1) = arg1;
	  va_end (p);
	  return rt_val;
	}

      hashcode = ((HOST_WIDE_INT) code + RTL_HASH (arg0) + RTL_HASH (arg1));
      for (h = attr_hash_table[hashcode % RTL_HASH_SIZE]; h; h = h->next)
	if (h->hashcode == hashcode
	    && GET_CODE (h->u.rtl) == code
	    && XEXP (h->u.rtl, 0) == arg0
	    && XEXP (h->u.rtl, 1) == arg1)
	  goto found;

      if (h == 0)
	{
	  rtl_obstack = hash_obstack;
	  rt_val = rtx_alloc (code);
	  XEXP (rt_val, 0) = arg0;
	  XEXP (rt_val, 1) = arg1;
	}
    }
  else if (GET_RTX_LENGTH (code) == 1
	   && GET_RTX_FORMAT (code)[0] == 's')
    {
      char * arg0 = va_arg (p, char *);

      if (code == SYMBOL_REF)
	arg0 = attr_string (arg0, strlen (arg0));

      hashcode = ((HOST_WIDE_INT) code + RTL_HASH (arg0));
      for (h = attr_hash_table[hashcode % RTL_HASH_SIZE]; h; h = h->next)
	if (h->hashcode == hashcode
	    && GET_CODE (h->u.rtl) == code
	    && XSTR (h->u.rtl, 0) == arg0)
	  goto found;

      if (h == 0)
	{
	  rtl_obstack = hash_obstack;
	  rt_val = rtx_alloc (code);
	  XSTR (rt_val, 0) = arg0;
	}
    }
  else if (GET_RTX_LENGTH (code) == 2
	   && GET_RTX_FORMAT (code)[0] == 's'
	   && GET_RTX_FORMAT (code)[1] == 's')
    {
      char *arg0 = va_arg (p, char *);
      char *arg1 = va_arg (p, char *);

      hashcode = ((HOST_WIDE_INT) code + RTL_HASH (arg0) + RTL_HASH (arg1));
      for (h = attr_hash_table[hashcode % RTL_HASH_SIZE]; h; h = h->next)
	if (h->hashcode == hashcode
	    && GET_CODE (h->u.rtl) == code
	    && XSTR (h->u.rtl, 0) == arg0
	    && XSTR (h->u.rtl, 1) == arg1)
	  goto found;

      if (h == 0)
	{
	  rtl_obstack = hash_obstack;
	  rt_val = rtx_alloc (code);
	  XSTR (rt_val, 0) = arg0;
	  XSTR (rt_val, 1) = arg1;
	}
    }
  else if (code == CONST_INT)
    {
      HOST_WIDE_INT arg0 = va_arg (p, HOST_WIDE_INT);
      if (arg0 == 0)
	return false_rtx;
      if (arg0 == 1)
	return true_rtx;
      goto nohash;
    }
  else
    {
    nohash:
      rt_val = rtx_alloc (code);	/* Allocate the storage space.  */
      
      fmt = GET_RTX_FORMAT (code);	/* Find the right format...  */
      for (i = 0; i < GET_RTX_LENGTH (code); i++)
	{
	  switch (*fmt++)
	    {
	    case '0':		/* Unused field.  */
	      break;

	    case 'i':		/* An integer?  */
	      XINT (rt_val, i) = va_arg (p, int);
	      break;

	    case 'w':		/* A wide integer? */
	      XWINT (rt_val, i) = va_arg (p, HOST_WIDE_INT);
	      break;

	    case 's':		/* A string?  */
	      XSTR (rt_val, i) = va_arg (p, char *);
	      break;

	    case 'e':		/* An expression?  */
	    case 'u':		/* An insn?  Same except when printing.  */
	      XEXP (rt_val, i) = va_arg (p, rtx);
	      break;

	    case 'E':		/* An RTX vector?  */
	      XVEC (rt_val, i) = va_arg (p, rtvec);
	      break;

	    default:
	      abort();
	    }
	}
      va_end (p);
      return rt_val;
    }

  rtl_obstack = old_obstack;
  va_end (p);
  attr_hash_add_rtx (hashcode, rt_val);
  RTX_INTEGRATED_P (rt_val) = 1;
  return rt_val;

 found:
  va_end (p);
  return h->u.rtl;
}

/* Create a new string printed with the printf line arguments into a space
   of at most LEN bytes:

   rtx attr_printf (len, format, [arg1, ..., argn])  */

#ifdef HAVE_VPRINTF

/*VARARGS2*/
static char *
attr_printf (va_alist)
     va_dcl
{
  va_list p;
  register int len;
  register char *fmt;
  register char *str;

  /* Print the string into a temporary location.  */
  va_start (p);
  len = va_arg (p, int);
  str = (char *) alloca (len);
  fmt = va_arg (p, char *);
  vsprintf (str, fmt, p);
  va_end (p);

  return attr_string (str, strlen (str));
}

#else /* not HAVE_VPRINTF */

static char *
attr_printf (len, fmt, arg1, arg2, arg3)
     int len;
     char *fmt;
     char *arg1, *arg2, *arg3; /* also int */
{
  register char *str;

  /* Print the string into a temporary location.  */
  str = (char *) alloca (len);
  sprintf (str, fmt, arg1, arg2, arg3);

  return attr_string (str, strlen (str));
}
#endif /* not HAVE_VPRINTF */

rtx
attr_eq (name, value)
     char *name, *value;
{
  return attr_rtx (EQ_ATTR, attr_string (name, strlen (name)),
		   attr_string (value, strlen (value)));
}

char *
attr_numeral (n)
     int n;
{
  return XSTR (make_numeric_value (n), 0);
}

/* Return a permanent (possibly shared) copy of a string STR (not assumed
   to be null terminated) with LEN bytes.  */

static char *
attr_string (str, len)
     char *str;
     int len;
{
  register struct attr_hash *h;
  int hashcode;
  int i;
  register char *new_str;

  /* Compute the hash code.  */
  hashcode = (len + 1) * 613 + (unsigned)str[0];
  for (i = 1; i <= len; i += 2)
    hashcode = ((hashcode * 613) + (unsigned)str[i]);
  if (hashcode < 0)
    hashcode = -hashcode;

  /* Search the table for the string.  */
  for (h = attr_hash_table[hashcode % RTL_HASH_SIZE]; h; h = h->next)
    if (h->hashcode == -hashcode && h->u.str[0] == str[0]
	&& !strncmp (h->u.str, str, len))
      return h->u.str;			/* <-- return if found.  */

  /* Not found; create a permanent copy and add it to the hash table.  */
  new_str = (char *) obstack_alloc (hash_obstack, len + 1);
  bcopy (str, new_str, len);
  new_str[len] = '\0';
  attr_hash_add_string (hashcode, new_str);

  return new_str;			/* Return the new string.  */
}

/* Check two rtx's for equality of contents,
   taking advantage of the fact that if both are hashed
   then they can't be equal unless they are the same object.  */

int
attr_equal_p (x, y)
     rtx x, y;
{
  return (x == y || (! (RTX_INTEGRATED_P (x) && RTX_INTEGRATED_P (y))
		     && rtx_equal_p (x, y)));
}

/* Copy an attribute value expression,
   descending to all depths, but not copying any
   permanent hashed subexpressions.  */

rtx
attr_copy_rtx (orig)
     register rtx orig;
{
  register rtx copy;
  register int i, j;
  register RTX_CODE code;
  register char *format_ptr;

  /* No need to copy a permanent object.  */
  if (RTX_INTEGRATED_P (orig))
    return orig;

  code = GET_CODE (orig);

  switch (code)
    {
    case REG:
    case QUEUED:
    case CONST_INT:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case CODE_LABEL:
    case PC:
    case CC0:
      return orig;
    }

  copy = rtx_alloc (code);
  PUT_MODE (copy, GET_MODE (orig));
  copy->in_struct = orig->in_struct;
  copy->volatil = orig->volatil;
  copy->unchanging = orig->unchanging;
  copy->integrated = orig->integrated;
  
  format_ptr = GET_RTX_FORMAT (GET_CODE (copy));

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

	case 'E':
	case 'V':
	  XVEC (copy, i) = XVEC (orig, i);
	  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) = attr_copy_rtx (XVECEXP (orig, i, j));
	    }
	  break;

	case 'n':
	case 'i':
	  XINT (copy, i) = XINT (orig, i);
	  break;

	case 'w':
	  XWINT (copy, i) = XWINT (orig, i);
	  break;

	case 's':
	case 'S':
	  XSTR (copy, i) = XSTR (orig, i);
	  break;

	default:
	  abort ();
	}
    }
  return copy;
}

/* Given a test expression for an attribute, ensure it is validly formed.
   IS_CONST indicates whether the expression is constant for each compiler
   run (a constant expression may not test any particular insn).

   Convert (eq_attr "att" "a1,a2") to (ior (eq_attr ... ) (eq_attrq ..))
   and (eq_attr "att" "!a1") to (not (eq_attr "att" "a1")).  Do the latter
   test first so that (eq_attr "att" "!a1,a2,a3") works as expected.

   Update the string address in EQ_ATTR expression to be the same used
   in the attribute (or `alternative_name') to speed up subsequent
   `find_attr' calls and eliminate most `strcmp' calls.

   Return the new expression, if any.   */

static rtx
check_attr_test (exp, is_const)
     rtx exp;
     int is_const;
{
  struct attr_desc *attr;
  struct attr_value *av;
  char *name_ptr, *p;
  rtx orexp, newexp;

  switch (GET_CODE (exp))
    {
    case EQ_ATTR:
      /* Handle negation test.  */
      if (XSTR (exp, 1)[0] == '!')
	return check_attr_test (attr_rtx (NOT,
					  attr_eq (XSTR (exp, 0),
						   &XSTR (exp, 1)[1])),
				is_const);

      else if (n_comma_elts (XSTR (exp, 1)) == 1)