Fix PR middle-end/20177 and add test case.

From-SVN: r96828

1 files changed, 2 insertions, 0 deletions

diff --git a/gcc/ddg.c b/gcc/ddg.c
index a54a87c..5a2cbee 100644
--- a/gcc/ddg.c
+++ b/gcc/ddg.c
@@ -187,6 +187,8 @@ create_ddg_dependence (ddg_ptr g, ddg_node_ptr src_node,
       else
 	free (e);
     }
+  else if (t == ANTI_DEP && dt == REG_DEP)
+    free (e);  /* We can fix broken anti register deps using reg-moves.  */
   else
     add_edge_to_ddg (g, e);
 }