PR middle-end/58344

	* expr.c (expand_expr_real_1): Handle init == NULL_TREE.

	* gcc.c-torture/compile/pr58344.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@206685 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 19 insertions, 1 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 400a152ce56..878a51b2510 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -9832,7 +9832,25 @@ expand_expr_real_1 (tree exp, rtx target, enum machine_mode tmode,
 		     || TREE_CODE (array) == CONST_DECL)
 		 && (init = ctor_for_folding (array)) != error_mark_node)
 	  {
-	    if (TREE_CODE (init) == CONSTRUCTOR)
+	    if (init == NULL_TREE)
+	      {
+		tree value = build_zero_cst (type);
+		if (TREE_CODE (value) == CONSTRUCTOR)
+		  {
+		    /* If VALUE is a CONSTRUCTOR, this optimization is only
+		       useful if this doesn't store the CONSTRUCTOR into
+		       memory.  If it does, it is more efficient to just
+		       load the data from the array directly.  */
+		    rtx ret = expand_constructor (value, target,
+						  modifier, true);
+		    if (ret == NULL_RTX)
+		      value = NULL_TREE;
+		  }
+
+		if (value)
+		  return expand_expr (value, target, tmode, modifier);
+	      }
+	    else if (TREE_CODE (init) == CONSTRUCTOR)
 	      {
 		unsigned HOST_WIDE_INT ix;
 		tree field, value;