Eliminate the call to removeTriviallyDeadNodes from updateFromGlobals graph,
moving it to the start of removeDeadNodes.  This speeds up DSA by 2s on perlbmk
from 41s


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10999 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index 0e7d3e6..9f8a4ef 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -1071,9 +1071,6 @@
       if (It != GlobalsGraph->ScalarMap.end())
         RC.merge(getNodeForValue(*I), It->second);
     }
-  
-  // Merging global nodes leaves behind unused nodes: get rid of them now.
-  removeTriviallyDeadNodes();
 }
 
 /// cloneInto - Clone the specified DSGraph into the current graph.  The
@@ -1597,7 +1594,7 @@
 
   // Reduce the amount of work we have to do... remove dummy nodes left over by
   // merging...
-  //removeTriviallyDeadNodes();
+  removeTriviallyDeadNodes();
 
   TIME_REGION(X, "removeDeadNodes");