- one more todo

[packages/gcc4.git] / gcc4-pr19505.patch

The problem here is that have two basic block forwarders which go to the
same basic block but destination of two different eh regions.  We cannot
forward both of these basic blocks to that other basic block.

The way I fixed the issue is to make sure that if we removing
a forwarder block which is coming in from a EH edge, make sure
that the destination basic block have only one single predecessor.
Yes this is too strong but there is no simple way to check if a basic
block is the destination of a different eh region.

--- gcc/gcc/tree-cfgcleanup.c	19 Aug 2005 18:52:55 -0000	2.7
+++ gcc/gcc/tree-cfgcleanup.c	24 Sep 2005 23:30:54 -0000
@@ -392,7 +392,18 @@ remove_forwarder_block (basic_block bb, 
 	    return false;
 	}
     }
-
+  /* Check to make sure that we can remove a forwarder block for eh edges.  */
+  FOR_EACH_EDGE (e, ei, bb->preds)
+    {
+      /* This check is too strong, we should also be checking eh regions
+         but this is much harder.  */
+      if (e->flags & EDGE_EH)
+        {
+	  if (!single_pred_p (dest))
+	    return false;
+	}
+    }
+  
   /* Redirect the edges.  */
   for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
     {