Register DAGUpdateListeners with SelectionDAG.

Instead of passing listener pointers to RAUW, let SelectionDAG itself
keep a linked list of interested listeners.

This makes it possible to have multiple listeners active at once, like
RAUWUpdateListener was already doing. It also makes it possible to
register listeners up the call stack without controlling all RAUW calls
below.

DAGUpdateListener uses an RAII pattern to add itself to the SelectionDAG
list of active listeners.

llvm-svn: 155248

1 files changed, 30 insertions, 48 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 0914c662766..1ed1ee77e46 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -328,15 +328,12 @@ namespace {
 class WorkListRemover : public SelectionDAG::DAGUpdateListener {
   DAGCombiner &DC;
 public:
-  explicit WorkListRemover(DAGCombiner &dc) : DC(dc) {}
+  explicit WorkListRemover(DAGCombiner &dc)
+    : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}
 
   virtual void NodeDeleted(SDNode *N, SDNode *E) {
     DC.removeFromWorkList(N);
   }
-
-  virtual void NodeUpdated(SDNode *N) {
-    // Ignore updates.
-  }
 };
 }
 
@@ -619,8 +616,7 @@ SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
                   N->getValueType(i) == To[i].getValueType()) &&
                  "Cannot combine value to value of different type!"));
   WorkListRemover DeadNodes(*this);
-  DAG.ReplaceAllUsesWith(N, To, &DeadNodes);
-
+  DAG.ReplaceAllUsesWith(N, To);
   if (AddTo) {
     // Push the new nodes and any users onto the worklist
     for (unsigned i = 0, e = NumTo; i != e; ++i) {
@@ -650,7 +646,7 @@ CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
   // Replace all uses.  If any nodes become isomorphic to other nodes and
   // are deleted, make sure to remove them from our worklist.
   WorkListRemover DeadNodes(*this);
-  DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &DeadNodes);
+  DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);
 
   // Push the new node and any (possibly new) users onto the worklist.
   AddToWorkList(TLO.New.getNode());
@@ -707,9 +703,8 @@ void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
         Trunc.getNode()->dump(&DAG);
         dbgs() << '\n');
   WorkListRemover DeadNodes(*this);
-  DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc, &DeadNodes);
-  DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1),
-                                &DeadNodes);
+  DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
+  DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
   removeFromWorkList(Load);
   DAG.DeleteNode(Load);
   AddToWorkList(Trunc.getNode());
@@ -961,8 +956,8 @@ bool DAGCombiner::PromoteLoad(SDValue Op) {
           Result.getNode()->dump(&DAG);
           dbgs() << '\n');
     WorkListRemover DeadNodes(*this);
-    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result, &DeadNodes);
-    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1), &DeadNodes);
+    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
+    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
     removeFromWorkList(N);
     DAG.DeleteNode(N);
     AddToWorkList(Result.getNode());
@@ -1047,12 +1042,12 @@ void DAGCombiner::Run(CombineLevel AtLevel) {
     DAG.TransferDbgValues(SDValue(N, 0), RV);
     WorkListRemover DeadNodes(*this);
     if (N->getNumValues() == RV.getNode()->getNumValues())
-      DAG.ReplaceAllUsesWith(N, RV.getNode(), &DeadNodes);
+      DAG.ReplaceAllUsesWith(N, RV.getNode());
     else {
       assert(N->getValueType(0) == RV.getValueType() &&
              N->getNumValues() == 1 && "Type mismatch");
       SDValue OpV = RV;
-      DAG.ReplaceAllUsesWith(N, &OpV, &DeadNodes);
+      DAG.ReplaceAllUsesWith(N, &OpV);
     }
 
     // Push the new node and any users onto the worklist
@@ -1327,8 +1322,7 @@ SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
   // uses remain, to ensure that the node can be safely deleted.
   do {
     for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
-      DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i),
-                                    &DeadNodes);
+      DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
   } while (!N->use_empty());
   removeFromWorkList(N);
   DAG.DeleteNode(N);
@@ -5041,8 +5035,7 @@ SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
 
   // Replace the old load's chain with the new load's chain.
   WorkListRemover DeadNodes(*this);
-  DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1),
-                                &DeadNodes);
+  DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
 
   // Shift the result left, if we've swallowed a left shift.
   SDValue Result = Load;
@@ -6185,7 +6178,7 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
           }
           // Replace the uses of SRL with SETCC
           WorkListRemover DeadNodes(*this);
-          DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
+          DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
           removeFromWorkList(N1.getNode());
           DAG.DeleteNode(N1.getNode());
           return SDValue(N, 0);   // Return N so it doesn't get rechecked!
@@ -6214,7 +6207,7 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
               Tmp.getNode()->dump(&DAG);
               dbgs() << '\n');
         WorkListRemover DeadNodes(*this);
-        DAG.ReplaceAllUsesOfValueWith(N1, Tmp, &DeadNodes);
+        DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
         removeFromWorkList(TheXor);
         DAG.DeleteNode(TheXor);
         return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
@@ -6240,7 +6233,7 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
                                    Equal ? ISD::SETEQ : ISD::SETNE);
       // Replace the uses of XOR with SETCC
       WorkListRemover DeadNodes(*this);
-      DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
+      DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
       removeFromWorkList(N1.getNode());
       DAG.DeleteNode(N1.getNode());
       return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
@@ -6431,21 +6424,17 @@ bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
         dbgs() << '\n');
   WorkListRemover DeadNodes(*this);
   if (isLoad) {
-    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0),
-                                  &DeadNodes);
-    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2),
-                                  &DeadNodes);
+    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
+    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
   } else {
-    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1),
-                                  &DeadNodes);
+    DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
   }
 
   // Finally, since the node is now dead, remove it from the graph.
   DAG.DeleteNode(N);
 
   // Replace the uses of Ptr with uses of the updated base value.
-  DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0),
-                                &DeadNodes);
+  DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
   removeFromWorkList(Ptr.getNode());
   DAG.DeleteNode(Ptr.getNode());
 
@@ -6559,13 +6548,10 @@ bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
               dbgs() << '\n');
         WorkListRemover DeadNodes(*this);
         if (isLoad) {
-          DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0),
-                                        &DeadNodes);
-          DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2),
-                                        &DeadNodes);
+          DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
+          DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
         } else {
-          DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1),
-                                        &DeadNodes);
+          DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
         }
 
         // Finally, since the node is now dead, remove it from the graph.
@@ -6573,8 +6559,7 @@ bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
 
         // Replace the uses of Use with uses of the updated base value.
         DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
-                                      Result.getValue(isLoad ? 1 : 0),
-                                      &DeadNodes);
+                                      Result.getValue(isLoad ? 1 : 0));
         removeFromWorkList(Op);
         DAG.DeleteNode(Op);
         return true;
@@ -6609,7 +6594,7 @@ SDValue DAGCombiner::visitLOAD(SDNode *N) {
               Chain.getNode()->dump(&DAG);
               dbgs() << "\n");
         WorkListRemover DeadNodes(*this);
-        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain, &DeadNodes);
+        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
 
         if (N->use_empty()) {
           removeFromWorkList(N);
@@ -6629,11 +6614,10 @@ SDValue DAGCombiner::visitLOAD(SDNode *N) {
               Undef.getNode()->dump(&DAG);
               dbgs() << " and 2 other values\n");
         WorkListRemover DeadNodes(*this);
-        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef, &DeadNodes);
+        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
         DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
-                                      DAG.getUNDEF(N->getValueType(1)),
-                                      &DeadNodes);
-        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain, &DeadNodes);
+                                      DAG.getUNDEF(N->getValueType(1)));
+        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
         removeFromWorkList(N);
         DAG.DeleteNode(N);
         return SDValue(N, 0);   // Return N so it doesn't get rechecked!
@@ -6955,8 +6939,7 @@ SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
       AddToWorkList(NewLD.getNode());
       AddToWorkList(NewVal.getNode());
       WorkListRemover DeadNodes(*this);
-      DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1),
-                                    &DeadNodes);
+      DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
       ++OpsNarrowed;
       return NewST;
     }
@@ -7013,8 +6996,7 @@ SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
     AddToWorkList(NewLD.getNode());
     AddToWorkList(NewST.getNode());
     WorkListRemover DeadNodes(*this);
-    DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1),
-                                  &DeadNodes);
+    DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
     ++LdStFP2Int;
     return NewST;
   }
@@ -7472,7 +7454,7 @@ SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
     WorkListRemover DeadNodes(*this);
     SDValue From[] = { SDValue(N, 0), SDValue(LN0,1) };
     SDValue To[] = { Load, Chain };
-    DAG.ReplaceAllUsesOfValuesWith(From, To, 2, &DeadNodes);
+    DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
     // Since we're explcitly calling ReplaceAllUses, add the new node to the
     // worklist explicitly as well.
     AddToWorkList(Load.getNode());