1 files changed, 37 insertions, 55 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 92671d1678c..0f2a5dff963 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -71,7 +71,9 @@ static const fltSemantics *EVTToAPFloatSemantics(EVT VT) {
   }
 }
 
-SelectionDAG::DAGUpdateListener::~DAGUpdateListener() {}
+// Default null implementations of the callbacks.
+void SelectionDAG::DAGUpdateListener::NodeDeleted(SDNode*, SDNode*) {}
+void SelectionDAG::DAGUpdateListener::NodeUpdated(SDNode*) {}
 
 //===----------------------------------------------------------------------===//
 //                              ConstantFPSDNode Class
@@ -544,16 +546,15 @@ void SelectionDAG::RemoveDeadNodes() {
 
 /// RemoveDeadNodes - This method deletes the unreachable nodes in the
 /// given list, and any nodes that become unreachable as a result.
-void SelectionDAG::RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes,
-                                   DAGUpdateListener *UpdateListener) {
+void SelectionDAG::RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes) {
 
   // Process the worklist, deleting the nodes and adding their uses to the
   // worklist.
   while (!DeadNodes.empty()) {
     SDNode *N = DeadNodes.pop_back_val();
 
-    if (UpdateListener)
-      UpdateListener->NodeDeleted(N, 0);
+    for (DAGUpdateListener *DUL = UpdateListeners; DUL; DUL = DUL->Next)
+      DUL->NodeDeleted(N, 0);
 
     // Take the node out of the appropriate CSE map.
     RemoveNodeFromCSEMaps(N);
@@ -574,7 +575,7 @@ void SelectionDAG::RemoveDeadNodes(SmallVectorImpl<SDNode *> &DeadNodes,
   }
 }
 
-void SelectionDAG::RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener){
+void SelectionDAG::RemoveDeadNode(SDNode *N){
   SmallVector<SDNode*, 16> DeadNodes(1, N);
 
   // Create a dummy node that adds a reference to the root node, preventing
@@ -582,7 +583,7 @@ void SelectionDAG::RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener){
   // dead node.)
   HandleSDNode Dummy(getRoot());
 
-  RemoveDeadNodes(DeadNodes, UpdateListener);
+  RemoveDeadNodes(DeadNodes);
 }
 
 void SelectionDAG::DeleteNode(SDNode *N) {
@@ -684,8 +685,7 @@ bool SelectionDAG::RemoveNodeFromCSEMaps(SDNode *N) {
 /// node. This transfer can potentially trigger recursive merging.
 ///
 void
-SelectionDAG::AddModifiedNodeToCSEMaps(SDNode *N,
-                                       DAGUpdateListener *UpdateListener) {
+SelectionDAG::AddModifiedNodeToCSEMaps(SDNode *N) {
   // For node types that aren't CSE'd, just act as if no identical node
   // already exists.
   if (!doNotCSE(N)) {
@@ -694,20 +694,19 @@ SelectionDAG::AddModifiedNodeToCSEMaps(SDNode *N,
       // If there was already an existing matching node, use ReplaceAllUsesWith
       // to replace the dead one with the existing one.  This can cause
       // recursive merging of other unrelated nodes down the line.
-      ReplaceAllUsesWith(N, Existing, UpdateListener);
+      ReplaceAllUsesWith(N, Existing);
 
-      // N is now dead.  Inform the listener if it exists and delete it.
-      if (UpdateListener)
-        UpdateListener->NodeDeleted(N, Existing);
+      // N is now dead. Inform the listeners and delete it.
+      for (DAGUpdateListener *DUL = UpdateListeners; DUL; DUL = DUL->Next)
+        DUL->NodeDeleted(N, Existing);
       DeleteNodeNotInCSEMaps(N);
       return;
     }
   }
 
-  // If the node doesn't already exist, we updated it.  Inform a listener if
-  // it exists.
-  if (UpdateListener)
-    UpdateListener->NodeUpdated(N);
+  // If the node doesn't already exist, we updated it.  Inform listeners.
+  for (DAGUpdateListener *DUL = UpdateListeners; DUL; DUL = DUL->Next)
+    DUL->NodeUpdated(N);
 }
 
 /// FindModifiedNodeSlot - Find a slot for the specified node if its operands
@@ -855,7 +854,7 @@ unsigned SelectionDAG::getEVTAlignment(EVT VT) const {
 SelectionDAG::SelectionDAG(const TargetMachine &tm, CodeGenOpt::Level OL)
   : TM(tm), TLI(*tm.getTargetLowering()), TSI(*tm.getSelectionDAGInfo()),
     OptLevel(OL), EntryNode(ISD::EntryToken, DebugLoc(), getVTList(MVT::Other)),
-    Root(getEntryNode()), Ordering(0) {
+    Root(getEntryNode()), Ordering(0), UpdateListeners(0) {
   AllNodes.push_back(&EntryNode);
   Ordering = new SDNodeOrdering();
   DbgInfo = new SDDbgInfo();
@@ -867,6 +866,7 @@ void SelectionDAG::init(MachineFunction &mf) {
 }
 
 SelectionDAG::~SelectionDAG() {
+  assert(!UpdateListeners && "Dangling registered DAGUpdateListeners");
   allnodes_clear();
   delete Ordering;
   delete DbgInfo;
@@ -5237,11 +5237,7 @@ namespace {
 /// pointed to by a use iterator is deleted, increment the use iterator
 /// so that it doesn't dangle.
 ///
-/// This class also manages a "downlink" DAGUpdateListener, to forward
-/// messages to ReplaceAllUsesWith's callers.
-///
 class RAUWUpdateListener : public SelectionDAG::DAGUpdateListener {
-  SelectionDAG::DAGUpdateListener *DownLink;
   SDNode::use_iterator &UI;
   SDNode::use_iterator &UE;
 
@@ -5249,21 +5245,13 @@ class RAUWUpdateListener : public SelectionDAG::DAGUpdateListener {
     // Increment the iterator as needed.
     while (UI != UE && N == *UI)
       ++UI;
-
-    // Then forward the message.
-    if (DownLink) DownLink->NodeDeleted(N, E);
-  }
-
-  virtual void NodeUpdated(SDNode *N) {
-    // Just forward the message.
-    if (DownLink) DownLink->NodeUpdated(N);
   }
 
 public:
-  RAUWUpdateListener(SelectionDAG::DAGUpdateListener *dl,
+  RAUWUpdateListener(SelectionDAG &d,
                      SDNode::use_iterator &ui,
                      SDNode::use_iterator &ue)
-    : DownLink(dl), UI(ui), UE(ue) {}
+    : SelectionDAG::DAGUpdateListener(d), UI(ui), UE(ue) {}
 };
 
 }
@@ -5273,8 +5261,7 @@ public:
 ///
 /// This version assumes From has a single result value.
 ///
-void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To,
-                                      DAGUpdateListener *UpdateListener) {
+void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To) {
   SDNode *From = FromN.getNode();
   assert(From->getNumValues() == 1 && FromN.getResNo() == 0 &&
          "Cannot replace with this method!");
@@ -5288,7 +5275,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To,
   // is replaced by To, we don't want to replace of all its users with To
   // too. See PR3018 for more info.
   SDNode::use_iterator UI = From->use_begin(), UE = From->use_end();
-  RAUWUpdateListener Listener(UpdateListener, UI, UE);
+  RAUWUpdateListener Listener(*this, UI, UE);
   while (UI != UE) {
     SDNode *User = *UI;
 
@@ -5307,7 +5294,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To,
 
     // Now that we have modified User, add it back to the CSE maps.  If it
     // already exists there, recursively merge the results together.
-    AddModifiedNodeToCSEMaps(User, &Listener);
+    AddModifiedNodeToCSEMaps(User);
   }
 
   // If we just RAUW'd the root, take note.
@@ -5321,8 +5308,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To,
 /// This version assumes that for each value of From, there is a
 /// corresponding value in To in the same position with the same type.
 ///
-void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To,
-                                      DAGUpdateListener *UpdateListener) {
+void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To) {
 #ifndef NDEBUG
   for (unsigned i = 0, e = From->getNumValues(); i != e; ++i)
     assert((!From->hasAnyUseOfValue(i) ||
@@ -5337,7 +5323,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To,
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
   SDNode::use_iterator UI = From->use_begin(), UE = From->use_end();
-  RAUWUpdateListener Listener(UpdateListener, UI, UE);
+  RAUWUpdateListener Listener(*this, UI, UE);
   while (UI != UE) {
     SDNode *User = *UI;
 
@@ -5356,7 +5342,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To,
 
     // Now that we have modified User, add it back to the CSE maps.  If it
     // already exists there, recursively merge the results together.
-    AddModifiedNodeToCSEMaps(User, &Listener);
+    AddModifiedNodeToCSEMaps(User);
   }
 
   // If we just RAUW'd the root, take note.
@@ -5369,16 +5355,14 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To,
 ///
 /// This version can replace From with any result values.  To must match the
 /// number and types of values returned by From.
-void SelectionDAG::ReplaceAllUsesWith(SDNode *From,
-                                      const SDValue *To,
-                                      DAGUpdateListener *UpdateListener) {
+void SelectionDAG::ReplaceAllUsesWith(SDNode *From, const SDValue *To) {
   if (From->getNumValues() == 1)  // Handle the simple case efficiently.
-    return ReplaceAllUsesWith(SDValue(From, 0), To[0], UpdateListener);
+    return ReplaceAllUsesWith(SDValue(From, 0), To[0]);
 
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
   SDNode::use_iterator UI = From->use_begin(), UE = From->use_end();
-  RAUWUpdateListener Listener(UpdateListener, UI, UE);
+  RAUWUpdateListener Listener(*this, UI, UE);
   while (UI != UE) {
     SDNode *User = *UI;
 
@@ -5398,7 +5382,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From,
 
     // Now that we have modified User, add it back to the CSE maps.  If it
     // already exists there, recursively merge the results together.
-    AddModifiedNodeToCSEMaps(User, &Listener);
+    AddModifiedNodeToCSEMaps(User);
   }
 
   // If we just RAUW'd the root, take note.
@@ -5409,14 +5393,13 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From,
 /// ReplaceAllUsesOfValueWith - Replace any uses of From with To, leaving
 /// uses of other values produced by From.getNode() alone.  The Deleted
 /// vector is handled the same way as for ReplaceAllUsesWith.
-void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To,
-                                             DAGUpdateListener *UpdateListener){
+void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To){
   // Handle the really simple, really trivial case efficiently.
   if (From == To) return;
 
   // Handle the simple, trivial, case efficiently.
   if (From.getNode()->getNumValues() == 1) {
-    ReplaceAllUsesWith(From, To, UpdateListener);
+    ReplaceAllUsesWith(From, To);
     return;
   }
 
@@ -5424,7 +5407,7 @@ void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To,
   // the ReplaceAllUsesWith above.
   SDNode::use_iterator UI = From.getNode()->use_begin(),
                        UE = From.getNode()->use_end();
-  RAUWUpdateListener Listener(UpdateListener, UI, UE);
+  RAUWUpdateListener Listener(*this, UI, UE);
   while (UI != UE) {
     SDNode *User = *UI;
     bool UserRemovedFromCSEMaps = false;
@@ -5460,7 +5443,7 @@ void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To,
 
     // Now that we have modified User, add it back to the CSE maps.  If it
     // already exists there, recursively merge the results together.
-    AddModifiedNodeToCSEMaps(User, &Listener);
+    AddModifiedNodeToCSEMaps(User);
   }
 
   // If we just RAUW'd the root, take note.
@@ -5489,11 +5472,10 @@ namespace {
 /// handled the same way as for ReplaceAllUsesWith.
 void SelectionDAG::ReplaceAllUsesOfValuesWith(const SDValue *From,
                                               const SDValue *To,
-                                              unsigned Num,
-                                              DAGUpdateListener *UpdateListener){
+                                              unsigned Num){
   // Handle the simple, trivial case efficiently.
   if (Num == 1)
-    return ReplaceAllUsesOfValueWith(*From, *To, UpdateListener);
+    return ReplaceAllUsesOfValueWith(*From, *To);
 
   // Read up all the uses and make records of them. This helps
   // processing new uses that are introduced during the
@@ -5538,7 +5520,7 @@ void SelectionDAG::ReplaceAllUsesOfValuesWith(const SDValue *From,
 
     // Now that we have modified User, add it back to the CSE maps.  If it
     // already exists there, recursively merge the results together.
-    AddModifiedNodeToCSEMaps(User, UpdateListener);
+    AddModifiedNodeToCSEMaps(User);
   }
 }