* tree-scalar-evolution.c (follow_ssa_edge_in_condition_phi):

[pf3gnuchains/gcc-fork.git] / gcc / tree-scalar-evolution.c

diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index 7d97d92..e26f1da 100644 (file)
--- a/gcc/tree-scalar-evolution.c
+++ b/gcc/tree-scalar-evolution.c
@@ -1398,6 +1398,11 @@ follow_ssa_edge_in_condition_phi (struct loop *loop,
 
   for (i = 1; i < PHI_NUM_ARGS (condition_phi); i++)
     {
+      /* Quickly give up when the evolution of one of the branches is
+        not known.  */
+      if (*evolution_of_loop == chrec_dont_know)
+       return true;
+
       if (!follow_ssa_edge_in_condition_phi_branch (i, loop, condition_phi,
                                                    halting_phi,
                                                    &evolution_of_branch,