re PR c/12553 ([tree-ssa] ICE in gimplify_expr with volatiles)

        PR c/12553
        * tree.c (build1) <ADDR_EXPR>: Set TREE_SIDE_EFFECTS
        appropriately.

        PR c/11446
        * stor-layout.c (layout_decl): Fix alignment handling.

From-SVN: r72724

gcc/ChangeLog

+2003-10-20  Jason Merrill  <jason@redhat.com>
+
+	PR c/12553
+	* tree.c (build1) <ADDR_EXPR>: Set TREE_SIDE_EFFECTS
+	appropriately.
+
+	PR c/11446
+	* stor-layout.c (layout_decl): Fix alignment handling.
+
 2003-10-20  Joseph S. Myers  <jsm@polyomino.org.uk>
 
 	* doc/extend.texi: Deprecate casts as lvalues.

gcc/stor-layout.c

@@ -450,20 +450,26 @@ layout_decl (tree decl, unsigned int known_align)
 	}
       else if (DECL_PACKED (decl) && DECL_USER_ALIGN (decl))
 	/* Don't touch DECL_ALIGN.  For other packed fields, go ahead and
-	   round up; we'll reduce it again below.  */;
+	   round up; we'll reduce it again below.  We want packing to
+	   supercede USER_ALIGN inherited from the type, but defer to
+	   alignment explicitly specified on the field decl.  */;
       else
+	{
 	  do_type_align (type, decl);
 
 	  /* If the field is of variable size, we can't misalign it since we
 	     have no way to make a temporary to align the result.  But this
 	     isn't an issue if the decl is not addressable.  Likewise if it
-	 is of unknown size.  */
+	     is of unknown size.
+
+	     Note that do_type_align may set DECL_USER_ALIGN, so we don't
+	     want to check it again here.  */
 	  if (DECL_PACKED (decl)
-	  && !DECL_USER_ALIGN (decl)
 	      && (DECL_NONADDRESSABLE_P (decl)
 		  || DECL_SIZE_UNIT (decl) == 0
 		  || TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST))
 	    DECL_ALIGN (decl) = MIN (DECL_ALIGN (decl), BITS_PER_UNIT);
+	}
 
       /* Should this be controlled by DECL_USER_ALIGN, too?  */
       if (maximum_field_alignment != 0)

gcc/tree.c

@@ -2466,6 +2466,29 @@ build1 (enum tree_code code, tree type, tree node)
       TREE_READONLY (t) = 0;
       break;
 
+    case ADDR_EXPR:
+      if (node)
+	{
+	  /* The address of a volatile decl or reference does not have
+	     side-effects.  But be careful not to ignore side-effects from
+	     other sources deeper in the expression--if node is a _REF and
+	     one of its operands has side-effects, so do we.  */
+	  if (TREE_THIS_VOLATILE (node))
+	    {
+	      TREE_SIDE_EFFECTS (t) = 0;
+	      if (!DECL_P (node))
+		{
+		  int i = first_rtl_op (TREE_CODE (node));
+		  for (; i >= 0; --i)
+		    {
+		      if (TREE_SIDE_EFFECTS (TREE_OPERAND (node, i)))
+			TREE_SIDE_EFFECTS (t) = 1;
+		    }
+		}
+	    }
+	}
+      break;
+
     default:
       if (TREE_CODE_CLASS (code) == '1' && node && TREE_CONSTANT (node))
 	TREE_CONSTANT (t) = 1;