[Bug c++/56961] stack overflow in gimplifier with volatile field

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56961

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
I suggest

Index: gcc/cp/cp-gimplify.c
===================================================================
--- gcc/cp/cp-gimplify.c        (revision 211262)
+++ gcc/cp/cp-gimplify.c        (working copy)
@@ -630,18 +630,8 @@ cp_gimplify_expr (tree *expr_p, gimple_s
               Also drop volatile variables on the RHS to avoid infinite
               recursion from gimplify_expr trying to load the value.  */
            if (!TREE_SIDE_EFFECTS (op1)
-               || (DECL_P (op1) && TREE_THIS_VOLATILE (op1)))
+               || TREE_THIS_VOLATILE (op1))
              *expr_p = op0;
-           else if (TREE_CODE (op1) == MEM_REF
-                    && TREE_THIS_VOLATILE (op1))
-             {
-               /* Similarly for volatile MEM_REFs on the RHS.  */
-               if (!TREE_SIDE_EFFECTS (TREE_OPERAND (op1, 0)))
-                 *expr_p = op0;
-               else
-                 *expr_p = build2 (COMPOUND_EXPR, TREE_TYPE (*expr_p),
-                                   TREE_OPERAND (op1, 0), op0);
-             }
            else
              *expr_p = build2 (COMPOUND_EXPR, TREE_TYPE (*expr_p),
                                op0, op1);