[llvm] r310163 - [LCG] Rather than walking the directed graph structure to update graph

[Chandler Carruth via llvm-commits]

Author: chandlerc
Date: Fri Aug  4 20:37:39 2017
New Revision: 310163

URL: http://llvm.org/viewvc/llvm-project?rev=310163&view=rev
Log:
[LCG] Rather than walking the directed graph structure to update graph
pointers in node objects, just walk the map from function to node.

It doesn't have stable ordering, but works just as well and is much
simpler. We don't need ordering when just updating internal pointers.

Modified:
    llvm/trunk/lib/Analysis/LazyCallGraph.cpp

Modified: llvm/trunk/lib/Analysis/LazyCallGraph.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LazyCallGraph.cpp?rev=310163&r1=310162&r2=310163&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LazyCallGraph.cpp (original)
+++ llvm/trunk/lib/Analysis/LazyCallGraph.cpp Fri Aug  4 20:37:39 2017
@@ -1684,20 +1684,10 @@ LazyCallGraph::Node &LazyCallGraph::inse
 }
 
 void LazyCallGraph::updateGraphPtrs() {
-  // Process all nodes updating the graph pointers.
-  {
-    SmallVector<Node *, 16> Worklist;
-    for (Edge &E : EntryEdges)
-      Worklist.push_back(&E.getNode());
-
-    while (!Worklist.empty()) {
-      Node &N = *Worklist.pop_back_val();
-      N.G = this;
-      if (N)
-        for (Edge &E : *N)
-          Worklist.push_back(&E.getNode());
-    }
-  }
+  // Walk the node map to update their graph pointers. While this iterates in
+  // an unstable order, the order has no effect so it remains correct.
+  for (auto &FunctionNodePair : NodeMap)
+    FunctionNodePair.second->G = this;
 
   for (auto *RC : PostOrderRefSCCs)
     RC->G = this;