[llvm-commits] [llvm] r58759 - /llvm/trunk/include/llvm/CodeGen/DAGISelHeader.h

[Dan Gohman]

Author: djg
Date: Wed Nov  5 11:13:57 2008
New Revision: 58759

URL: http://llvm.org/viewvc/llvm-project?rev=58759&view=rev
Log:
Update some comments to reflect the new code.

Modified:
    llvm/trunk/include/llvm/CodeGen/DAGISelHeader.h

Modified: llvm/trunk/include/llvm/CodeGen/DAGISelHeader.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/DAGISelHeader.h?rev=58759&r1=58758&r2=58759&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/DAGISelHeader.h (original)
+++ llvm/trunk/include/llvm/CodeGen/DAGISelHeader.h Wed Nov  5 11:13:57 2008
@@ -50,7 +50,10 @@
   explicit ISelUpdater(SelectionDAG::allnodes_iterator &isp)
     : ISelPosition(isp) {}
   
-  /// NodeDeleted - remove node from the selection queue.
+  /// NodeDeleted - Handle nodes deleted from the graph. If the
+  /// node being deleted is the current ISelPosition node, update
+  /// ISelPosition.
+  ///
   virtual void NodeDeleted(SDNode *N, SDNode *E) {
     if (ISelPosition == SelectionDAG::allnodes_iterator(N))
       ++ISelPosition;
@@ -100,8 +103,10 @@
   HandleSDNode Dummy(CurDAG->getRoot());
   ISelPosition = next(SelectionDAG::allnodes_iterator(CurDAG->getRoot().getNode()));
 
-  // Select pending nodes from the instruction selection queue
-  // until no more nodes are left for selection.
+  // The AllNodes list is now topological-sorted. Visit the
+  // nodes by starting at the end of the list (the root of the
+  // graph) and preceding back toward the beginning (the entry
+  // node).
   while (ISelPosition != CurDAG->allnodes_begin()) {
     SDNode *Node = --ISelPosition;
 #if 0