re PR tree-optimization/45704 (load byte instruction is used for volatile int)

[platform/upstream/gcc.git] / gcc / gimplify.c

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index e5b011a..4e6a037 100644 (file)
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -4200,9 +4200,18 @@ gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p,
             This kind of code arises in C++ when an object is bound
             to a const reference, and if "x" is a TARGET_EXPR we want
             to take advantage of the optimization below.  */
+           bool volatile_p = TREE_THIS_VOLATILE (*from_p);
            tree t = gimple_fold_indirect_ref_rhs (TREE_OPERAND (*from_p, 0));
            if (t)
              {
+               if (TREE_THIS_VOLATILE (t) != volatile_p)
+                 {
+                   if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
+                     t = build_simple_mem_ref_loc (EXPR_LOCATION (*from_p),
+                                                   build_fold_addr_expr (t));
+                   if (REFERENCE_CLASS_P (t))
+                     TREE_THIS_VOLATILE (t) = volatile_p;
+                 }
                *from_p = t;
                ret = GS_OK;
                changed = true;