1 files changed, 10 insertions, 0 deletions
diff --git a/gcc/expr.c b/gcc/expr.c
index 5872ab0..4ac7252 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -1733,6 +1733,16 @@ emit_block_move (x, y, size, method)
   if (size == 0)
     abort ();
 
+  /* Set MEM_SIZE as appropriate for this block copy.  The main place this
+     can be incorrect is coming from __builtin_memcpy.  */
+  if (GET_CODE (size) == CONST_INT)
+    {
+      x = shallow_copy_rtx (x);
+      y = shallow_copy_rtx (y);
+      set_mem_size (x, size);
+      set_mem_size (y, size);
+    }
+
   if (GET_CODE (size) == CONST_INT && MOVE_BY_PIECES_P (INTVAL (size), align))
     move_by_pieces (x, y, INTVAL (size), align);
   else if (emit_block_move_via_movstr (x, y, size, align))