===================================================================
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+extern const unsigned long base;
+static inline void wreg(unsigned char val, unsigned long addr) __attribute__((always_inline));
+static inline void wreg(unsigned char val, unsigned long addr)
+{
+ *((volatile unsigned char *) (__SIZE_TYPE__) (base + addr)) = val;
+}
+void wreg_twice(void)
+{
+ wreg(0, 42);
+ wreg(0, 42);
+}
+
+/* We should not remove the second null character store to (base+42) address. */
+/* { dg-final { scan-tree-dump-times " ={v} 0;" 2 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
===================================================================
@@ -848,6 +848,7 @@ remap_gimple_op_r (tree *tp, int *walk_s
ptr, TREE_OPERAND (*tp, 1));
TREE_THIS_NOTRAP (*tp) = TREE_THIS_NOTRAP (old);
TREE_THIS_VOLATILE (*tp) = TREE_THIS_VOLATILE (old);
+ TREE_SIDE_EFFECTS (*tp) = TREE_SIDE_EFFECTS (old);
TREE_NO_WARNING (*tp) = TREE_NO_WARNING (old);
*walk_subtrees = 0;
return NULL;