1 files changed, 4 insertions, 1 deletions
diff --git a/gcc/dce.c b/gcc/dce.c
index 11f8edb..9a42da7 100644
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -704,7 +704,10 @@ init_dce (bool fast)
   if (!df_in_progress)
     {
       if (!fast)
-	df_chain_add_problem (DF_UD_CHAIN);
+	{
+	  df_set_flags (DF_RD_PRUNE_DEAD_DEFS);
+	  df_chain_add_problem (DF_UD_CHAIN);
+	}
       df_analyze ();
     }