backthreader dump fix

This fixes odd SUCCEEDED dumps from the backthreader registry that
can happen even though register_jump_thread cancelled the thread
as invalid.

	* tree-ssa-threadbackward.cc (back_threader::maybe_register_path):
	Check whether the registry register_path rejected the path.
	(back_threader_registry::register_path): Return whether
	register_jump_thread succeeded.

diff --git a/gcc/tree-ssa-threadbackward.cc b/gcc/tree-ssa-threadbackward.cc
index 3acd66a7780a02a0bfc68739f56484beb5e62890..332a1d2a1dd61fb372b13175ec69326867f11b78 100644 (file)
--- a/gcc/tree-ssa-threadbackward.cc
+++ b/gcc/tree-ssa-threadbackward.cc
@@ -243,10 +243,9 @@ back_threader::maybe_register_path ()
          bool irreducible = false;
          if (m_profit.profitable_path_p (m_path, m_name, taken_edge,
                                          &irreducible)
-             && debug_counter ())
+             && debug_counter ()
+             && m_registry.register_path (m_path, taken_edge))
            {
-             m_registry.register_path (m_path, taken_edge);
-
              if (irreducible)
                vect_free_loop_info_assumptions (m_path[0]->loop_father);
            }
@@ -858,8 +857,7 @@ back_threader_registry::register_path (const vec<basic_block> &m_path,
     }
 
   push_edge (jump_thread_path, taken_edge, EDGE_NO_COPY_SRC_BLOCK);
-  register_jump_thread (jump_thread_path);
-  return true;
+  return register_jump_thread (jump_thread_path);
 }
 
 // Thread all suitable paths in the current function.