SOme bugfixes in expr.c

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

These are fixes to some regressions caused by my changes in the last
few weeks plus a performance issue I noticed in safe_from_p.

Tested on alphaev56-dec-osf4.0c.

Sat Oct 27 17:32:04 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>

	* expr.c (stor_constructor_field): Always call adjust_address.
	Copy TARGET before changing its alias set.
	(store_field): Likewise, for TO_RTX.
	(get_inner_reference): Stop at PLACEHOLDER_EXPR if can't find
	replacement.
	(safe_from_p, case ADDR_EXPR): Properly check for conflict.
	(find_placeholder): Return 0 if can't find object.
	(expand_expr, case PLACEHOLDER_EXPR): Abort if find_placeholder
	returns 0.

*** expr.c	2001/10/25 12:55:16	1.365
--- expr.c	2001/10/27 21:21:44
*************** store_constructor_field (target, bitsize
*** 4473,4483 ****
        && (bitpos == 0 || GET_CODE (target) == MEM))
      {
!       if (bitpos != 0)
! 	target
! 	  = adjust_address (target,
! 			    GET_MODE (target) == BLKmode
! 			    || 0 != (bitpos
! 				     % GET_MODE_ALIGNMENT (GET_MODE (target)))
! 			    ? BLKmode : VOIDmode, bitpos / BITS_PER_UNIT);
  
  
--- 4473,4482 ----
        && (bitpos == 0 || GET_CODE (target) == MEM))
      {
!       target
! 	= adjust_address (target,
! 			  GET_MODE (target) == BLKmode
! 			  || 0 != (bitpos
! 				   % GET_MODE_ALIGNMENT (GET_MODE (target)))
! 			  ? BLKmode : VOIDmode, bitpos / BITS_PER_UNIT);
  
  
*************** store_constructor_field (target, bitsize
*** 4489,4493 ****
        if (GET_CODE (target) == MEM && ! MEM_KEEP_ALIAS_SET_P (target)
  	  && MEM_ALIAS_SET (target) != 0)
! 	set_mem_alias_set (target, alias_set);
  
        store_constructor (exp, target, align, cleared, bitsize / BITS_PER_UNIT);
--- 4488,4495 ----
        if (GET_CODE (target) == MEM && ! MEM_KEEP_ALIAS_SET_P (target)
  	  && MEM_ALIAS_SET (target) != 0)
! 	{
! 	  target = copy_rtx (target);
! 	  set_mem_alias_set (target, alias_set);
! 	}
  
        store_constructor (exp, target, align, cleared, bitsize / BITS_PER_UNIT);
*************** store_field (target, bitsize, bitpos, mo
*** 5355,5359 ****
        MEM_SET_IN_STRUCT_P (to_rtx, 1);
        if (!MEM_KEEP_ALIAS_SET_P (to_rtx) && MEM_ALIAS_SET (to_rtx) != 0)
! 	set_mem_alias_set (to_rtx, alias_set);
  
        return store_expr (exp, to_rtx, value_mode != VOIDmode);
--- 5357,5364 ----
        MEM_SET_IN_STRUCT_P (to_rtx, 1);
        if (!MEM_KEEP_ALIAS_SET_P (to_rtx) && MEM_ALIAS_SET (to_rtx) != 0)
! 	{
! 	  to_rtx = copy_rtx (to_rtx);
! 	  set_mem_alias_set (to_rtx, alias_set);
! 	}
  
        return store_expr (exp, to_rtx, value_mode != VOIDmode);
*************** get_inner_reference (exp, pbitsize, pbit
*** 5503,5507 ****
        else if (TREE_CODE (exp) == PLACEHOLDER_EXPR)
  	{
! 	  exp = find_placeholder (exp, &placeholder_ptr);
  	  continue;
  	}
--- 5508,5521 ----
        else if (TREE_CODE (exp) == PLACEHOLDER_EXPR)
  	{
! 	  tree new = find_placeholder (exp, &placeholder_ptr);
! 
! 	  /* If we couldn't find the replacement, return the PLACEHOLDER_EXPR.
! 	     We might have been called from tree optimization where we
! 	     haven't set up an object yet.  */
! 	  if (new == 0)
! 	    break;
! 	  else
! 	    exp = new;
! 
  	  continue;
  	}
*************** safe_from_p (x, exp, top_p)
*** 5779,5785 ****
  	{
  	case ADDR_EXPR:
! 	  return (staticp (TREE_OPERAND (exp, 0))
! 		  || TREE_STATIC (exp)
! 		  || safe_from_p (x, TREE_OPERAND (exp, 0), 0));
  
  	case INDIRECT_REF:
--- 5793,5816 ----
  	{
  	case ADDR_EXPR:
! 	  /* If the operand is static or we are static, we can't conflict.
! 	     Likewise if we don't conflict with the operand at all.  */
! 	  if (staticp (TREE_OPERAND (exp, 0))
! 	      || TREE_STATIC (exp)
! 	      || safe_from_p (x, TREE_OPERAND (exp, 0), 0))
! 	    return 1;
! 
! 	  /* Otherwise, the only way this can conflict is if we are taking
! 	     the address of a DECL a that address if part of X, which is
! 	     very rare.  */
! 	  exp = TREE_OPERAND (exp, 0);
! 	  if (DECL_P (exp))
! 	    {
! 	      if (!DECL_RTL_SET_P (exp)
! 		  || GET_CODE (DECL_RTL (exp)) != MEM)
! 		return 0;
! 	      else
! 		exp_rtl = XEXP (DECL_RTL (exp), 0);
! 	    }
! 	  break;
  
  	case INDIRECT_REF:
*************** highest_pow2_factor (exp)
*** 6024,6029 ****
     PLACEHOLDER_EXPR.  An object "matches" if it is of the type of the
     PLACEHOLDER_EXPR or a pointer type to it.  For further information, see
!    tree.def.  If no such object is found, abort.  If PLIST is nonzero, it is
!    a location which initially points to a starting location in the
     placeholder list (zero means start of the list) and where a pointer into
     the placeholder list at which the object is found is placed.  */
--- 6055,6060 ----
     PLACEHOLDER_EXPR.  An object "matches" if it is of the type of the
     PLACEHOLDER_EXPR or a pointer type to it.  For further information, see
!    tree.def.  If no such object is found, return 0.  If PLIST is nonzero, it
!    is a location which initially points to a starting location in the
     placeholder list (zero means start of the list) and where a pointer into
     the placeholder list at which the object is found is placed.  */
*************** find_placeholder (exp, plist)
*** 6084,6088 ****
      }
  
!   abort ();
  }
  
--- 6115,6119 ----
      }
  
!   return 0;
  }
  

*************** expand_expr (exp, target, tmode, modifie
*** 6618,6621 ****
--- 6649,6655 ----
  
  	exp = find_placeholder (exp, &placeholder_expr);
+ 	if (exp == 0)
+ 	  abort ();
+ 
  	placeholder_list = TREE_CHAIN (placeholder_expr);
  	temp = expand_expr (exp, original_target, tmode, ro_modifier);