1 files changed, 19 insertions, 37 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
index 7dd8f501aa5..6d6b9c7c0f0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
@@ -60,7 +60,6 @@ static void CheckForPhysRegDependency(SDNode *Def, SDNode *User, unsigned Op,
 SUnit *ScheduleDAG::Clone(SUnit *Old) {
   SUnit *SU = NewSUnit(Old->getNode());
   SU->OrigNode = Old->OrigNode;
-  SU->FlaggedNodes = Old->FlaggedNodes;
   SU->Latency = Old->Latency;
   SU->isTwoAddress = Old->isTwoAddress;
   SU->isCommutable = Old->isCommutable;
@@ -99,23 +98,19 @@ void ScheduleDAG::BuildSchedUnits() {
     // nodes.  Nodes can have at most one flag input and one flag output.  Flags
     // are required the be the last operand and result of a node.
     
-    // Scan up, adding flagged preds to FlaggedNodes.
+    // Scan up to find flagged preds.
     SDNode *N = NI;
     if (N->getNumOperands() &&
         N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Flag) {
       do {
         N = N->getOperand(N->getNumOperands()-1).getNode();
-        NodeSUnit->FlaggedNodes.push_back(N);
         assert(N->getNodeId() == -1 && "Node already inserted!");
         N->setNodeId(NodeSUnit->NodeNum);
       } while (N->getNumOperands() &&
                N->getOperand(N->getNumOperands()-1).getValueType()== MVT::Flag);
-      std::reverse(NodeSUnit->FlaggedNodes.begin(),
-                   NodeSUnit->FlaggedNodes.end());
     }
     
-    // Scan down, adding this node and any flagged succs to FlaggedNodes if they
-    // have a user of the flag operand.
+    // Scan down to find any flagged succs.
     N = NI;
     while (N->getValueType(N->getNumValues()-1) == MVT::Flag) {
       SDValue FlagVal(N, N->getNumValues()-1);
@@ -126,7 +121,6 @@ void ScheduleDAG::BuildSchedUnits() {
            UI != E; ++UI)
         if (FlagVal.isOperandOf(*UI)) {
           HasFlagUse = true;
-          NodeSUnit->FlaggedNodes.push_back(N);
           assert(N->getNodeId() == -1 && "Node already inserted!");
           N->setNodeId(NodeSUnit->NodeNum);
           N = *UI;
@@ -135,8 +129,9 @@ void ScheduleDAG::BuildSchedUnits() {
       if (!HasFlagUse) break;
     }
     
-    // Now all flagged nodes are in FlaggedNodes and N is the bottom-most node.
-    // Update the SUnit
+    // If there are flag operands involved, N is now the bottom-most node
+    // of the sequence of nodes that are flagged together.
+    // Update the SUnit.
     NodeSUnit->setNode(N);
     assert(N->getNodeId() == -1 && "Node already inserted!");
     N->setNodeId(NodeSUnit->NodeNum);
@@ -163,11 +158,7 @@ void ScheduleDAG::BuildSchedUnits() {
     }
     
     // Find all predecessors and successors of the group.
-    // Temporarily add N to make code simpler.
-    SU->FlaggedNodes.push_back(MainNode);
-    
-    for (unsigned n = 0, e = SU->FlaggedNodes.size(); n != e; ++n) {
-      SDNode *N = SU->FlaggedNodes[n];
+    for (SDNode *N = SU->getNode(); N; N = N->getFlaggedNode()) {
       if (N->isMachineOpcode() &&
           TII->get(N->getMachineOpcode()).getImplicitDefs() &&
           CountResults(N) > TII->get(N->getMachineOpcode()).getNumDefs())
@@ -191,9 +182,6 @@ void ScheduleDAG::BuildSchedUnits() {
         SU->addPred(OpSU, isChain, false, PhysReg, Cost);
       }
     }
-    
-    // Remove MainNode from FlaggedNodes again.
-    SU->FlaggedNodes.pop_back();
   }
 }
 
@@ -209,17 +197,9 @@ void ScheduleDAG::ComputeLatency(SUnit *SU) {
   }
 
   SU->Latency = 0;
-  if (SU->getNode()->isMachineOpcode()) {
-    unsigned SchedClass = TII->get(SU->getNode()->getMachineOpcode()).getSchedClass();
-    const InstrStage *S = InstrItins.begin(SchedClass);
-    const InstrStage *E = InstrItins.end(SchedClass);
-    for (; S != E; ++S)
-      SU->Latency += S->Cycles;
-  }
-  for (unsigned i = 0, e = SU->FlaggedNodes.size(); i != e; ++i) {
-    SDNode *FNode = SU->FlaggedNodes[i];
-    if (FNode->isMachineOpcode()) {
-      unsigned SchedClass = TII->get(FNode->getMachineOpcode()).getSchedClass();
+  for (SDNode *N = SU->getNode(); N; N = N->getFlaggedNode()) {
+    if (N->isMachineOpcode()) {
+      unsigned SchedClass = TII->get(N->getMachineOpcode()).getSchedClass();
       const InstrStage *S = InstrItins.begin(SchedClass);
       const InstrStage *E = InstrItins.end(SchedClass);
       for (; S != E; ++S)
@@ -397,17 +377,19 @@ void ScheduleDAG::Run() {
 /// a group of nodes flagged together.
 void SUnit::dump(const SelectionDAG *G) const {
   cerr << "SU(" << NodeNum << "): ";
-  if (Node)
-    Node->dump(G);
+  if (getNode())
+    getNode()->dump(G);
   else
     cerr << "CROSS RC COPY ";
   cerr << "\n";
-  if (FlaggedNodes.size() != 0) {
-    for (unsigned i = 0, e = FlaggedNodes.size(); i != e; i++) {
-      cerr << "    ";
-      FlaggedNodes[i]->dump(G);
-      cerr << "\n";
-    }
+  SmallVector<SDNode *, 4> FlaggedNodes;
+  for (SDNode *N = getNode()->getFlaggedNode(); N; N = N->getFlaggedNode())
+    FlaggedNodes.push_back(N);
+  while (!FlaggedNodes.empty()) {
+    cerr << "    ";
+    FlaggedNodes.back()->dump(G);
+    cerr << "\n";
+    FlaggedNodes.pop_back();
   }
 }