Mark necessary 2nd and later args for delete op.

2019-07-31  Martin Liska  <mliska@suse.cz>

	* tree-ssa-dce.c (propagate_necessity): Delete operator can
	have size and (or) alignment as 2nd and later arguments.
	Mark all of them as necessary.

From-SVN: r273929

gcc/ChangeLog

+2019-07-31  Martin Liska  <mliska@suse.cz>
+
+	* tree-ssa-dce.c (propagate_necessity): Delete operator can
+	have size and (or) alignment as 2nd and later arguments.
+	Mark all of them as necessary.
+
 2019-07-31  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/91178

gcc/tree-ssa-dce.c

@@ -824,13 +824,16 @@ propagate_necessity (bool aggressive)
 			   || DECL_FUNCTION_CODE (def_callee) == BUILT_IN_CALLOC))
 		      || DECL_IS_REPLACEABLE_OPERATOR_NEW_P (def_callee)))
 		{
-		  /* Some delete operators have size as 2nd argument.  */
+		  /* Delete operators can have alignment and (or) size as next
+		     arguments.  When being a SSA_NAME, they must be marked
+		     as necessary.  */
 		  if (is_delete_operator && gimple_call_num_args (stmt) >= 2)
-		    {
-		      tree size_argument = gimple_call_arg (stmt, 1);
-		      if (TREE_CODE (size_argument) == SSA_NAME)
-			mark_operand_necessary (size_argument);
-		    }
+		    for (unsigned i = 1; i < gimple_call_num_args (stmt); i++)
+		      {
+			tree arg = gimple_call_arg (stmt, i);
+			if (TREE_CODE (arg) == SSA_NAME)
+			  mark_operand_necessary (arg);
+		      }
 
 		  continue;
 		}