Force block enders to be simulated once.

From-SVN: r151273

gcc/ChangeLog

+2009-09-01  Richard Henderson  <rth@redhat.com>
+
+	* tree-ssa-ccp.c (ccp_initialize): Make sure to simulate 
+	stmt_ends_pp_p statements at least once.
+	* tree-vrp.c (vrp_initialize): Likewise.
+	(vrp_visit_stmt): Be prepared for non-interesting stmts.
+
 2009-09-01  Dodji Seketeli  <dodji@redhat.com>
 
 	PR bootstrap/41205

gcc/tree-ssa-ccp.c

@@ -650,7 +650,15 @@ ccp_initialize (void)
       for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i))
         {
 	  gimple stmt = gsi_stmt (i);
-	  bool is_varying = surely_varying_stmt_p (stmt);
+	  bool is_varying;
+
+	  /* If the statement is a control insn, then we do not
+	     want to avoid simulating the statement once.  Failure
+	     to do so means that those edges will never get added.  */
+	  if (stmt_ends_bb_p (stmt))
+	    is_varying = false;
+	  else
+	    is_varying = surely_varying_stmt_p (stmt);
 
 	  if (is_varying)
 	    {

gcc/tree-vrp.c

@@ -5317,7 +5317,12 @@ vrp_initialize (void)
         {
 	  gimple stmt = gsi_stmt (si);
 
-	  if (!stmt_interesting_for_vrp (stmt))
+ 	  /* If the statement is a control insn, then we do not
+ 	     want to avoid simulating the statement once.  Failure
+ 	     to do so means that those edges will never get added.  */
+	  if (stmt_ends_bb_p (stmt))
+	    prop_set_simulate_again (stmt, true);
+	  else if (!stmt_interesting_for_vrp (stmt))
 	    {
 	      ssa_op_iter i;
 	      tree def;
@@ -5326,9 +5331,7 @@ vrp_initialize (void)
 	      prop_set_simulate_again (stmt, false);
 	    }
 	  else
-	    {
-	      prop_set_simulate_again (stmt, true);
-	    }
+	    prop_set_simulate_again (stmt, true);
 	}
     }
 }
@@ -6087,7 +6090,9 @@ vrp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p)
       fprintf (dump_file, "\n");
     }
 
-  if (is_gimple_assign (stmt) || is_gimple_call (stmt))
+  if (!stmt_interesting_for_vrp (stmt))
+    gcc_assert (stmt_ends_bb_p (stmt));
+  else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
     {
       /* In general, assignments with virtual operands are not useful
 	 for deriving ranges, with the obvious exception of calls to