Re: c/2404: arm-linux-gcc ice

[Philip Blundell <philb@gnu.org>]

The following reply was made to PR c/2404; it has been noted by GNATS.

From: Philip Blundell <philb@gnu.org>
To: bkohlen@intrinsyc.com
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: c/2404: arm-linux-gcc ice 
Date: Tue, 27 Mar 2001 22:24:04 +0100

 >shadow.c: In function `shadowImageGlyphBlt':
 >shadow.c:1173: Internal compiler error in `purge_addressof_1', at function.c:3
 >183
 >Please submit a full bug report.
 >See <URL: http://www.gnu.org/software/gcc/bugs.html > for instructions.
 
 Does this patch help at all?
 
 p.
 
 --- gcc/function.c	1999/05/20 22:26:35	1.90.4.1
 +++ gcc/function.c	1999/07/16 09:30:04
 @@ -3042,6 +3042,105 @@
     extracted by usage MEM with narrower mode. */
  static rtx purge_addressof_replacements;
  
 +/* Return 1 if X and Y are identical-looking rtx's.
 +   This is the Lisp function EQUAL for rtx arguments.  */
 +
 +int
 +rtx_equal_for_addressof_p (x, y)
 +     rtx x, y;
 +{
 +  register int i;
 +  register int j;
 +  register enum rtx_code code;
 +  register char *fmt;
 +
 +  if (x == y)
 +    return 1;
 +  if (x == 0 || y == 0)
 +    return 0;
 +
 +  code = GET_CODE (x);
 +  /* Rtx's of different codes cannot be equal.  */
 +  if (code != GET_CODE (y))
 +    return 0;
 +
 +  /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
 +     (REG:SI x) and (REG:HI x) are NOT equivalent. 
 +     But (MEM:SI x) and (MEM:HI x) are equivalent for our purposes.  */
 +
 +  if (code != MEM && (GET_MODE (x) != GET_MODE (y)))
 +    return 0;
 +
 +  /* REG, LABEL_REF, and SYMBOL_REF can be compared nonrecursively.  */
 +
 +  if (code == REG)
 +    return REGNO (x) == REGNO (y);
 +  else if (code == LABEL_REF)
 +    return XEXP (x, 0) == XEXP (y, 0);
 +  else if (code == SYMBOL_REF)
 +    return XSTR (x, 0) == XSTR (y, 0);
 +  else if (code == SCRATCH || code == CONST_DOUBLE)
 +    return 0;
 +
 +  /* Compare the elements.  If any pair of corresponding elements
 +     fail to match, return 0 for the whole things.  */
 +
 +  fmt = GET_RTX_FORMAT (code);
 +  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
 +    {
 +      switch (fmt[i])
 +	{
 +	case 'w':
 +	  if (XWINT (x, i) != XWINT (y, i))
 +	    return 0;
 +	  break;
 +
 +	case 'n':
 +	case 'i':
 +	  if (XINT (x, i) != XINT (y, i))
 +	    return 0;
 +	  break;
 +
 +	case 'V':
 +	case 'E':
 +	  /* Two vectors must have the same length.  */
 +	  if (XVECLEN (x, i) != XVECLEN (y, i))
 +	    return 0;
 +
 +	  /* And the corresponding elements must match.  */
 +	  for (j = 0; j < XVECLEN (x, i); j++)
 +	    if (rtx_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0)
 +	      return 0;
 +	  break;
 +
 +	case 'e':
 +	  if (rtx_equal_p (XEXP (x, i), XEXP (y, i)) == 0)
 +	    return 0;
 +	  break;
 +
 +	case 'S':
 +	case 's':
 +	  if (strcmp (XSTR (x, i), XSTR (y, i)))
 +	    return 0;
 +	  break;
 +
 +	case 'u':
 +	  /* These are just backpointers, so they don't matter.  */
 +	  break;
 +
 +	case '0':
 +	  break;
 +
 +	  /* It is believed that rtx's at this level will never
 +	     contain anything but integers and other rtx's,
 +	     except for within LABEL_REFs and SYMBOL_REFs.  */
 +	default:
 +	  abort ();
 +	}
 +    }
 +  return 1;
 +}
 +
  /* Helper function for purge_addressof.  See if the rtx expression at *LOC
     in INSN needs to be changed.  If FORCE, always put any ADDRESSOFs into
     the stack.  */
 @@ -3122,7 +3221,7 @@
  	      for (tem = purge_bitfield_addressof_replacements;
  		   tem != NULL_RTX;
  		   tem = XEXP (XEXP (tem, 1), 1))
 -		if (rtx_equal_p (x, XEXP (tem, 0)))
 +		if (rtx_equal_for_addressof_p (x, XEXP (tem, 0)))
  		  {
  		    *loc = XEXP (XEXP (tem, 1), 0);
  		    return;
 @@ -3132,7 +3231,7 @@
  	      for (tem = purge_addressof_replacements;
  		   tem != NULL_RTX;
  		   tem = XEXP (XEXP (tem, 1), 1))
 -		if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
 +		if (rtx_equal_for_addressof_p (XEXP (x, 0), XEXP (tem, 0)))
  		  {
  		    rtx z = XEXP (XEXP (tem, 1), 0);