2005-12-13 Petr Machata <machata@post.cz>

[pf3gnuchains/gcc-fork.git] / gcc / tree-cfgcleanup.c

diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index 51b2fc5..7e719c1 100644 (file)
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -81,11 +81,11 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
       switch (TREE_CODE (expr))
        {
        case COND_EXPR:
-         val = COND_EXPR_COND (expr);
+         val = fold (COND_EXPR_COND (expr));
          break;
 
        case SWITCH_EXPR:
-         val = SWITCH_COND (expr);
+         val = fold (SWITCH_COND (expr));
          if (TREE_CODE (val) != INTEGER_CST)
            return false;
          break;
@@ -489,14 +489,12 @@ cleanup_forwarder_blocks (void)
   return changed;
 }
 
-/* Remove unreachable blocks and other miscellaneous clean up work.  */
+/* Do one round of CFG cleanup.  */
 
-bool
-cleanup_tree_cfg (void)
+static bool
+cleanup_tree_cfg_1 (void)
 {
-  bool retval = false;
-
-  timevar_push (TV_TREE_CLEANUP_CFG);
+  bool retval;
 
   retval = cleanup_control_flow ();
   retval |= delete_unreachable_blocks ();
@@ -516,27 +514,44 @@ cleanup_tree_cfg (void)
       end_recording_case_labels ();
     }
 
-#ifdef ENABLE_CHECKING
-  if (retval)
+  /* Merging the blocks may create new opportunities for folding
+     conditional branches (due to the elimination of single-valued PHI
+     nodes).  */
+  retval |= merge_seq_blocks ();
+
+  return retval;
+}
+
+
+/* Remove unreachable blocks and other miscellaneous clean up work.
+   Return true if the flowgraph was modified, false otherwise.  */
+
+bool
+cleanup_tree_cfg (void)
+{
+  bool retval, changed;
+
+  timevar_push (TV_TREE_CLEANUP_CFG);
+
+  /* Iterate until there are no more cleanups left to do.  If any
+     iteration changed the flowgraph, set CHANGED to true.  */
+  changed = false;
+  do
     {
-      gcc_assert (!cleanup_control_flow ());
-      gcc_assert (!delete_unreachable_blocks ());
-      if (optimize > 0)
-       gcc_assert (!cleanup_forwarder_blocks ());
+      retval = cleanup_tree_cfg_1 ();
+      changed |= retval;
     }
-#endif
-
-  /* Merging the blocks creates no new opportunities for the other
-     optimizations, so do it here.  */
-  retval |= merge_seq_blocks ();
+  while (retval);
 
   compact_blocks ();
 
 #ifdef ENABLE_CHECKING
   verify_flow_info ();
 #endif
+
   timevar_pop (TV_TREE_CLEANUP_CFG);
-  return retval;
+
+  return changed;
 }
 
 /* Cleanup cfg and repair loop structures.  */