PR tree-optimization/33920

        * tree-if-conv.c (tree_if_conversion): Force predicate of single
        successor bb to true when predecessor bb has NULL predicate.
        (find_phi_replacement_condition): Assert that tmp_cond is non-null.

testsuite/ChangeLog:

        PR tree-optimization/33920
        * gcc.dg/tree-ssa/pr33290.c: New test.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@129696 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 2 deletions

diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index f97c23db93b..9d2fe265791 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -189,8 +189,14 @@ tree_if_conversion (struct loop *loop, bool for_vectorizer)
       if (single_succ_p (bb))
 	{
 	  basic_block bb_n = single_succ (bb);
-	  if (cond != NULL_TREE)
-	    add_to_predicate_list (bb_n, cond);
+
+	  /* Successor bb inherits predicate of its predecessor. If there
+	     is no predicate in predecessor bb, then consider successor bb
+	     as always executed.  */
+	  if (cond == NULL_TREE)
+	    cond = boolean_true_node;
+
+	  add_to_predicate_list (bb_n, cond);
 	}
     }
 
@@ -724,6 +730,8 @@ find_phi_replacement_condition (struct loop *loop,
 
   /* Select condition that is not TRUTH_NOT_EXPR.  */
   tmp_cond = (first_edge->src)->aux;
+  gcc_assert (tmp_cond);
+
   if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
     {
       edge tmp_edge;