Don't take address of ap unless necessary

2015-05-12  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/66010
	* gimplify.c (gimplify_modify_expr): Handle new do_deref argument of
	ifn_va_arg.
	* gimplify.h (gimplify_va_arg_internal): Remove loc parameter.
	(gimplify_va_arg_internal): Remove loc parameter.  Assert no array-typed
	va_lists are passed, and remove corresponding handling.
	(gimplify_va_arg_expr): Only take address of ap if necessary.  Add
	do_deref argument to ifn_va_arg.
	* tree-stdarg.c (expand_ifn_va_arg_1): Handle new do_deref argument of
	ifn_va_arg.

	* c-common.c (build_va_arg): Don't mark ap addressable unless necessary.

	* gcc.dg/tree-ssa/stdarg-2.c: Undo scan xfails for f15.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@223054 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 7 deletions

diff --git a/gcc/tree-stdarg.c b/gcc/tree-stdarg.c
index 1356374ba140..3bede7efd6e3 100644
--- a/gcc/tree-stdarg.c
+++ b/gcc/tree-stdarg.c
@@ -1042,7 +1042,7 @@ expand_ifn_va_arg_1 (function *fun)
     for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
       {
 	gimple stmt = gsi_stmt (i);
-	tree ap, expr, lhs, type;
+	tree ap, expr, lhs, type, do_deref;
 	gimple_seq pre = NULL, post = NULL;
 
 	if (!gimple_call_ifn_va_arg_p (stmt))
@@ -1052,24 +1052,27 @@ expand_ifn_va_arg_1 (function *fun)
 
 	type = TREE_TYPE (TREE_TYPE (gimple_call_arg (stmt, 1)));
 	ap = gimple_call_arg (stmt, 0);
-	ap = build_fold_indirect_ref (ap);
+	do_deref = gimple_call_arg (stmt, 2);
+
+	if (do_deref == integer_one_node)
+	  ap = build_fold_indirect_ref (ap);
 
 	push_gimplify_context (false);
 
-	expr = gimplify_va_arg_internal (ap, type, gimple_location (stmt),
-					 &pre, &post);
+	expr = gimplify_va_arg_internal (ap, type, &pre, &post);
 
 	lhs = gimple_call_lhs (stmt);
 	if (lhs != NULL_TREE)
 	  {
+	    unsigned int nargs = gimple_call_num_args (stmt);
 	    gcc_assert (useless_type_conversion_p (TREE_TYPE (lhs), type));
 
-	    if (gimple_call_num_args (stmt) == 3)
+	    if (nargs == 4)
 	      {
 		/* We've transported the size of with WITH_SIZE_EXPR here as
-		   the 3rd argument of the internal fn call.  Now reinstate
+		   the last argument of the internal fn call.  Now reinstate
 		   it.  */
-		tree size = gimple_call_arg (stmt, 2);
+		tree size = gimple_call_arg (stmt, nargs - 1);
 		expr = build2 (WITH_SIZE_EXPR, TREE_TYPE (expr), expr, size);
 	      }