It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
new file mode 100644
index 0000000..06b2329
--- /dev/null
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
@@ -0,0 +1,725 @@
+//===---- ScheduleDAG.cpp - Implement the ScheduleDAG class ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by James M. Laskey and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This implements a simple two pass scheduler.  The first pass attempts to push
+// backward any lengthy instructions and critical paths.  The second pass packs
+// instructions into semi-optimal time slots.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "pre-RA-sched"
+#include "llvm/Type.h"
+#include "llvm/CodeGen/ScheduleDAG.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SSARegMap.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtras.h"
+using namespace llvm;
+
+/// BuildSchedUnits - Build SUnits from the selection dag that we are input.
+/// This SUnit graph is similar to the SelectionDAG, but represents flagged
+/// together nodes with a single SUnit.
+void ScheduleDAG::BuildSchedUnits() {
+  // Reserve entries in the vector for each of the SUnits we are creating.  This
+  // ensure that reallocation of the vector won't happen, so SUnit*'s won't get
+  // invalidated.
+  SUnits.reserve(std::distance(DAG.allnodes_begin(), DAG.allnodes_end()));
+  
+  const InstrItineraryData &InstrItins = TM.getInstrItineraryData();
+  
+  for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin(),
+       E = DAG.allnodes_end(); NI != E; ++NI) {
+    if (isPassiveNode(NI))  // Leaf node, e.g. a TargetImmediate.
+      continue;
+    
+    // If this node has already been processed, stop now.
+    if (SUnitMap[NI]) continue;
+    
+    SUnit *NodeSUnit = NewSUnit(NI);
+    
+    // See if anything is flagged to this node, if so, add them to flagged
+    // 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.
+    SDNode *N = NI;
+    if (N->getNumOperands() &&
+        N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Flag) {
+      do {
+        N = N->getOperand(N->getNumOperands()-1).Val;
+        NodeSUnit->FlaggedNodes.push_back(N);
+        SUnitMap[N] = NodeSUnit;
+      } 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.
+    N = NI;
+    while (N->getValueType(N->getNumValues()-1) == MVT::Flag) {
+      SDOperand FlagVal(N, N->getNumValues()-1);
+      
+      // There are either zero or one users of the Flag result.
+      bool HasFlagUse = false;
+      for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); 
+           UI != E; ++UI)
+        if (FlagVal.isOperand(*UI)) {
+          HasFlagUse = true;
+          NodeSUnit->FlaggedNodes.push_back(N);
+          SUnitMap[N] = NodeSUnit;
+          N = *UI;
+          break;
+        }
+      if (!HasFlagUse) break;
+    }
+    
+    // Now all flagged nodes are in FlaggedNodes and N is the bottom-most node.
+    // Update the SUnit
+    NodeSUnit->Node = N;
+    SUnitMap[N] = NodeSUnit;
+    
+    // Compute the latency for the node.  We use the sum of the latencies for
+    // all nodes flagged together into this SUnit.
+    if (InstrItins.isEmpty()) {
+      // No latency information.
+      NodeSUnit->Latency = 1;
+    } else {
+      NodeSUnit->Latency = 0;
+      if (N->isTargetOpcode()) {
+        unsigned SchedClass = TII->getSchedClass(N->getTargetOpcode());
+        InstrStage *S = InstrItins.begin(SchedClass);
+        InstrStage *E = InstrItins.end(SchedClass);
+        for (; S != E; ++S)
+          NodeSUnit->Latency += S->Cycles;
+      }
+      for (unsigned i = 0, e = NodeSUnit->FlaggedNodes.size(); i != e; ++i) {
+        SDNode *FNode = NodeSUnit->FlaggedNodes[i];
+        if (FNode->isTargetOpcode()) {
+          unsigned SchedClass = TII->getSchedClass(FNode->getTargetOpcode());
+          InstrStage *S = InstrItins.begin(SchedClass);
+          InstrStage *E = InstrItins.end(SchedClass);
+          for (; S != E; ++S)
+            NodeSUnit->Latency += S->Cycles;
+        }
+      }
+    }
+  }
+  
+  // Pass 2: add the preds, succs, etc.
+  for (unsigned su = 0, e = SUnits.size(); su != e; ++su) {
+    SUnit *SU = &SUnits[su];
+    SDNode *MainNode = SU->Node;
+    
+    if (MainNode->isTargetOpcode()) {
+      unsigned Opc = MainNode->getTargetOpcode();
+      for (unsigned i = 0, ee = TII->getNumOperands(Opc); i != ee; ++i) {
+        if (TII->getOperandConstraint(Opc, i, TOI::TIED_TO) != -1) {
+          SU->isTwoAddress = true;
+          break;
+        }
+      }
+      if (TII->isCommutableInstr(Opc))
+        SU->isCommutable = true;
+    }
+    
+    // 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 (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
+        SDNode *OpN = N->getOperand(i).Val;
+        if (isPassiveNode(OpN)) continue;   // Not scheduled.
+        SUnit *OpSU = SUnitMap[OpN];
+        assert(OpSU && "Node has no SUnit!");
+        if (OpSU == SU) continue;           // In the same group.
+
+        MVT::ValueType OpVT = N->getOperand(i).getValueType();
+        assert(OpVT != MVT::Flag && "Flagged nodes should be in same sunit!");
+        bool isChain = OpVT == MVT::Other;
+        
+        if (SU->addPred(OpSU, isChain)) {
+          if (!isChain) {
+            SU->NumPreds++;
+            SU->NumPredsLeft++;
+          } else {
+            SU->NumChainPredsLeft++;
+          }
+        }
+        if (OpSU->addSucc(SU, isChain)) {
+          if (!isChain) {
+            OpSU->NumSuccs++;
+            OpSU->NumSuccsLeft++;
+          } else {
+            OpSU->NumChainSuccsLeft++;
+          }
+        }
+      }
+    }
+    
+    // Remove MainNode from FlaggedNodes again.
+    SU->FlaggedNodes.pop_back();
+  }
+  
+  return;
+}
+
+void ScheduleDAG::CalculateDepths() {
+  std::vector<std::pair<SUnit*, unsigned> > WorkList;
+  for (unsigned i = 0, e = SUnits.size(); i != e; ++i)
+    if (SUnits[i].Preds.size() == 0/* && &SUnits[i] != Entry*/)
+      WorkList.push_back(std::make_pair(&SUnits[i], 0U));
+
+  while (!WorkList.empty()) {
+    SUnit *SU = WorkList.back().first;
+    unsigned Depth = WorkList.back().second;
+    WorkList.pop_back();
+    if (SU->Depth == 0 || Depth > SU->Depth) {
+      SU->Depth = Depth;
+      for (SUnit::succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
+           I != E; ++I)
+        WorkList.push_back(std::make_pair(I->first, Depth+1));
+    }
+  }
+}
+
+void ScheduleDAG::CalculateHeights() {
+  std::vector<std::pair<SUnit*, unsigned> > WorkList;
+  SUnit *Root = SUnitMap[DAG.getRoot().Val];
+  WorkList.push_back(std::make_pair(Root, 0U));
+
+  while (!WorkList.empty()) {
+    SUnit *SU = WorkList.back().first;
+    unsigned Height = WorkList.back().second;
+    WorkList.pop_back();
+    if (SU->Height == 0 || Height > SU->Height) {
+      SU->Height = Height;
+      for (SUnit::pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
+           I != E; ++I)
+        WorkList.push_back(std::make_pair(I->first, Height+1));
+    }
+  }
+}
+
+/// CountResults - The results of target nodes have register or immediate
+/// operands first, then an optional chain, and optional flag operands (which do
+/// not go into the machine instrs.)
+unsigned ScheduleDAG::CountResults(SDNode *Node) {
+  unsigned N = Node->getNumValues();
+  while (N && Node->getValueType(N - 1) == MVT::Flag)
+    --N;
+  if (N && Node->getValueType(N - 1) == MVT::Other)
+    --N;    // Skip over chain result.
+  return N;
+}
+
+/// CountOperands  The inputs to target nodes have any actual inputs first,
+/// followed by an optional chain operand, then flag operands.  Compute the
+/// number of actual operands that  will go into the machine instr.
+unsigned ScheduleDAG::CountOperands(SDNode *Node) {
+  unsigned N = Node->getNumOperands();
+  while (N && Node->getOperand(N - 1).getValueType() == MVT::Flag)
+    --N;
+  if (N && Node->getOperand(N - 1).getValueType() == MVT::Other)
+    --N; // Ignore chain if it exists.
+  return N;
+}
+
+static const TargetRegisterClass *getInstrOperandRegClass(
+        const MRegisterInfo *MRI, 
+        const TargetInstrInfo *TII,
+        const TargetInstrDescriptor *II,
+        unsigned Op) {
+  if (Op >= II->numOperands) {
+    assert((II->Flags & M_VARIABLE_OPS)&& "Invalid operand # of instruction");
+    return NULL;
+  }
+  const TargetOperandInfo &toi = II->OpInfo[Op];
+  return (toi.Flags & M_LOOK_UP_PTR_REG_CLASS)
+         ? TII->getPointerRegClass() : MRI->getRegClass(toi.RegClass);
+}
+
+static void CreateVirtualRegisters(SDNode *Node,
+                                   unsigned NumResults, 
+                                   const MRegisterInfo *MRI,
+                                   MachineInstr *MI,
+                                   SSARegMap *RegMap,
+                                   const TargetInstrInfo *TII,
+                                   const TargetInstrDescriptor &II,
+                                   DenseMap<SDOperand, unsigned> &VRBaseMap) {
+  for (unsigned i = 0; i < NumResults; ++i) {
+    // If the specific node value is only used by a CopyToReg and the dest reg
+    // is a vreg, use the CopyToReg'd destination register instead of creating
+    // a new vreg.
+    unsigned VRBase = 0;
+    for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+         UI != E; ++UI) {
+      SDNode *Use = *UI;
+      if (Use->getOpcode() == ISD::CopyToReg && 
+          Use->getOperand(2).Val == Node &&
+          Use->getOperand(2).ResNo == i) {
+        unsigned Reg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
+        if (MRegisterInfo::isVirtualRegister(Reg)) {
+          VRBase = Reg;
+          MI->addRegOperand(Reg, true);
+          break;
+        }
+      }
+    }
+
+    if (VRBase == 0) {
+      // Create the result registers for this node and add the result regs to
+      // the machine instruction.
+      const TargetRegisterClass *RC = getInstrOperandRegClass(MRI, TII, &II, i);
+      assert(RC && "Isn't a register operand!");
+      VRBase = RegMap->createVirtualRegister(RC);
+      MI->addRegOperand(VRBase, true);
+    }
+
+    bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,i), VRBase));
+    assert(isNew && "Node emitted out of order - early");
+  }
+}
+
+/// getVR - Return the virtual register corresponding to the specified result
+/// of the specified node.
+static unsigned getVR(SDOperand Op, DenseMap<SDOperand, unsigned> &VRBaseMap) {
+  DenseMap<SDOperand, unsigned>::iterator I = VRBaseMap.find(Op);
+  assert(I != VRBaseMap.end() && "Node emitted out of order - late");
+  return I->second;
+}
+
+
+/// AddOperand - Add the specified operand to the specified machine instr.  II
+/// specifies the instruction information for the node, and IIOpNum is the
+/// operand number (in the II) that we are adding. IIOpNum and II are used for 
+/// assertions only.
+void ScheduleDAG::AddOperand(MachineInstr *MI, SDOperand Op,
+                             unsigned IIOpNum,
+                             const TargetInstrDescriptor *II,
+                             DenseMap<SDOperand, unsigned> &VRBaseMap) {
+  if (Op.isTargetOpcode()) {
+    // Note that this case is redundant with the final else block, but we
+    // include it because it is the most common and it makes the logic
+    // simpler here.
+    assert(Op.getValueType() != MVT::Other &&
+           Op.getValueType() != MVT::Flag &&
+           "Chain and flag operands should occur at end of operand list!");
+    
+    // Get/emit the operand.
+    unsigned VReg = getVR(Op, VRBaseMap);
+    const TargetInstrDescriptor *TID = MI->getInstrDescriptor();
+    bool isOptDef = (IIOpNum < TID->numOperands)
+      ? (TID->OpInfo[IIOpNum].Flags & M_OPTIONAL_DEF_OPERAND) : false;
+    MI->addRegOperand(VReg, isOptDef);
+    
+    // Verify that it is right.
+    assert(MRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
+    if (II) {
+      const TargetRegisterClass *RC =
+                          getInstrOperandRegClass(MRI, TII, II, IIOpNum);
+      assert(RC && "Don't have operand info for this instruction!");
+      const TargetRegisterClass *VRC = RegMap->getRegClass(VReg);
+      if (VRC != RC) {
+        cerr << "Register class of operand and regclass of use don't agree!\n";
+#ifndef NDEBUG
+        cerr << "Operand = " << IIOpNum << "\n";
+        cerr << "Op->Val = "; Op.Val->dump(&DAG); cerr << "\n";
+        cerr << "MI = "; MI->print(cerr);
+        cerr << "VReg = " << VReg << "\n";
+        cerr << "VReg RegClass     size = " << VRC->getSize()
+             << ", align = " << VRC->getAlignment() << "\n";
+        cerr << "Expected RegClass size = " << RC->getSize()
+             << ", align = " << RC->getAlignment() << "\n";
+#endif
+        cerr << "Fatal error, aborting.\n";
+        abort();
+      }
+    }
+  } else if (ConstantSDNode *C =
+             dyn_cast<ConstantSDNode>(Op)) {
+    MI->addImmOperand(C->getValue());
+  } else if (RegisterSDNode *R =
+             dyn_cast<RegisterSDNode>(Op)) {
+    MI->addRegOperand(R->getReg(), false);
+  } else if (GlobalAddressSDNode *TGA =
+             dyn_cast<GlobalAddressSDNode>(Op)) {
+    MI->addGlobalAddressOperand(TGA->getGlobal(), TGA->getOffset());
+  } else if (BasicBlockSDNode *BB =
+             dyn_cast<BasicBlockSDNode>(Op)) {
+    MI->addMachineBasicBlockOperand(BB->getBasicBlock());
+  } else if (FrameIndexSDNode *FI =
+             dyn_cast<FrameIndexSDNode>(Op)) {
+    MI->addFrameIndexOperand(FI->getIndex());
+  } else if (JumpTableSDNode *JT =
+             dyn_cast<JumpTableSDNode>(Op)) {
+    MI->addJumpTableIndexOperand(JT->getIndex());
+  } else if (ConstantPoolSDNode *CP = 
+             dyn_cast<ConstantPoolSDNode>(Op)) {
+    int Offset = CP->getOffset();
+    unsigned Align = CP->getAlignment();
+    const Type *Type = CP->getType();
+    // MachineConstantPool wants an explicit alignment.
+    if (Align == 0) {
+      Align = TM.getTargetData()->getPreferredTypeAlignmentShift(Type);
+      if (Align == 0) {
+        // Alignment of vector types.  FIXME!
+        Align = TM.getTargetData()->getTypeSize(Type);
+        Align = Log2_64(Align);
+      }
+    }
+    
+    unsigned Idx;
+    if (CP->isMachineConstantPoolEntry())
+      Idx = ConstPool->getConstantPoolIndex(CP->getMachineCPVal(), Align);
+    else
+      Idx = ConstPool->getConstantPoolIndex(CP->getConstVal(), Align);
+    MI->addConstantPoolIndexOperand(Idx, Offset);
+  } else if (ExternalSymbolSDNode *ES = 
+             dyn_cast<ExternalSymbolSDNode>(Op)) {
+    MI->addExternalSymbolOperand(ES->getSymbol());
+  } else {
+    assert(Op.getValueType() != MVT::Other &&
+           Op.getValueType() != MVT::Flag &&
+           "Chain and flag operands should occur at end of operand list!");
+    unsigned VReg = getVR(Op, VRBaseMap);
+    MI->addRegOperand(VReg, false);
+    
+    // Verify that it is right.
+    assert(MRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?");
+    if (II) {
+      const TargetRegisterClass *RC =
+                            getInstrOperandRegClass(MRI, TII, II, IIOpNum);
+      assert(RC && "Don't have operand info for this instruction!");
+      assert(RegMap->getRegClass(VReg) == RC &&
+             "Register class of operand and regclass of use don't agree!");
+    }
+  }
+  
+}
+
+// Returns the Register Class of a physical register
+static const TargetRegisterClass *getPhysicalRegisterRegClass(
+        const MRegisterInfo *MRI,
+        MVT::ValueType VT,
+        unsigned reg) {
+  assert(MRegisterInfo::isPhysicalRegister(reg) &&
+         "reg must be a physical register");
+  // Pick the register class of the right type that contains this physreg.
+  for (MRegisterInfo::regclass_iterator I = MRI->regclass_begin(),
+         E = MRI->regclass_end(); I != E; ++I)
+    if ((*I)->hasType(VT) && (*I)->contains(reg))
+      return *I;
+  assert(false && "Couldn't find the register class");
+  return 0;
+}
+
+/// EmitNode - Generate machine code for an node and needed dependencies.
+///
+void ScheduleDAG::EmitNode(SDNode *Node, 
+                           DenseMap<SDOperand, unsigned> &VRBaseMap) {
+  // If machine instruction
+  if (Node->isTargetOpcode()) {
+    unsigned Opc = Node->getTargetOpcode();
+    const TargetInstrDescriptor &II = TII->get(Opc);
+
+    unsigned NumResults = CountResults(Node);
+    unsigned NodeOperands = CountOperands(Node);
+    unsigned NumMIOperands = NodeOperands + NumResults;
+#ifndef NDEBUG
+    assert((unsigned(II.numOperands) == NumMIOperands ||
+            (II.Flags & M_VARIABLE_OPS)) &&
+           "#operands for dag node doesn't match .td file!"); 
+#endif
+
+    // Create the new machine instruction.
+    MachineInstr *MI = new MachineInstr(II);
+    
+    // Add result register values for things that are defined by this
+    // instruction.
+    if (NumResults)
+      CreateVirtualRegisters(Node, NumResults, MRI, MI, RegMap,
+                             TII, II, VRBaseMap);
+    
+    // Emit all of the actual operands of this instruction, adding them to the
+    // instruction as appropriate.
+    for (unsigned i = 0; i != NodeOperands; ++i)
+      AddOperand(MI, Node->getOperand(i), i+NumResults, &II, VRBaseMap);
+
+    // Commute node if it has been determined to be profitable.
+    if (CommuteSet.count(Node)) {
+      MachineInstr *NewMI = TII->commuteInstruction(MI);
+      if (NewMI == 0)
+        DOUT << "Sched: COMMUTING FAILED!\n";
+      else {
+        DOUT << "Sched: COMMUTED TO: " << *NewMI;
+        if (MI != NewMI) {
+          delete MI;
+          MI = NewMI;
+        }
+      }
+    }
+
+    // Now that we have emitted all operands, emit this instruction itself.
+    if ((II.Flags & M_USES_CUSTOM_DAG_SCHED_INSERTION) == 0) {
+      BB->insert(BB->end(), MI);
+    } else {
+      // Insert this instruction into the end of the basic block, potentially
+      // taking some custom action.
+      BB = DAG.getTargetLoweringInfo().InsertAtEndOfBasicBlock(MI, BB);
+    }
+  } else {
+    switch (Node->getOpcode()) {
+    default:
+#ifndef NDEBUG
+      Node->dump(&DAG);
+#endif
+      assert(0 && "This target-independent node should have been selected!");
+    case ISD::EntryToken: // fall thru
+    case ISD::TokenFactor:
+    case ISD::LABEL:
+      break;
+    case ISD::CopyToReg: {
+      unsigned InReg;
+      if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Node->getOperand(2)))
+        InReg = R->getReg();
+      else
+        InReg = getVR(Node->getOperand(2), VRBaseMap);
+      unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
+      if (InReg != DestReg)  {// Coalesced away the copy?
+        const TargetRegisterClass *TRC = 0;
+        // Get the target register class
+        if (MRegisterInfo::isVirtualRegister(InReg))
+          TRC = RegMap->getRegClass(InReg);
+        else
+          TRC = getPhysicalRegisterRegClass(MRI,
+                                            Node->getOperand(2).getValueType(),
+                                            InReg);
+        MRI->copyRegToReg(*BB, BB->end(), DestReg, InReg, TRC);
+      }
+      break;
+    }
+    case ISD::CopyFromReg: {
+      unsigned VRBase = 0;
+      unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
+      if (MRegisterInfo::isVirtualRegister(SrcReg)) {
+        // Just use the input register directly!
+        bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,0),SrcReg));
+        assert(isNew && "Node emitted out of order - early");
+        break;
+      }
+
+      // If the node is only used by a CopyToReg and the dest reg is a vreg, use
+      // the CopyToReg'd destination register instead of creating a new vreg.
+      for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end();
+           UI != E; ++UI) {
+        SDNode *Use = *UI;
+        if (Use->getOpcode() == ISD::CopyToReg && 
+            Use->getOperand(2).Val == Node) {
+          unsigned DestReg = cast<RegisterSDNode>(Use->getOperand(1))->getReg();
+          if (MRegisterInfo::isVirtualRegister(DestReg)) {
+            VRBase = DestReg;
+            break;
+          }
+        }
+      }
+
+      // Figure out the register class to create for the destreg.
+      const TargetRegisterClass *TRC = 0;
+      if (VRBase) {
+        TRC = RegMap->getRegClass(VRBase);
+      } else {
+        TRC = getPhysicalRegisterRegClass(MRI, Node->getValueType(0), SrcReg);
+
+        // Create the reg, emit the copy.
+        VRBase = RegMap->createVirtualRegister(TRC);
+      }
+      MRI->copyRegToReg(*BB, BB->end(), VRBase, SrcReg, TRC);
+
+      bool isNew = VRBaseMap.insert(std::make_pair(SDOperand(Node,0), VRBase));
+      assert(isNew && "Node emitted out of order - early");
+      break;
+    }
+    case ISD::INLINEASM: {
+      unsigned NumOps = Node->getNumOperands();
+      if (Node->getOperand(NumOps-1).getValueType() == MVT::Flag)
+        --NumOps;  // Ignore the flag operand.
+      
+      // Create the inline asm machine instruction.
+      MachineInstr *MI =
+        new MachineInstr(BB, TII->get(TargetInstrInfo::INLINEASM));
+
+      // Add the asm string as an external symbol operand.
+      const char *AsmStr =
+        cast<ExternalSymbolSDNode>(Node->getOperand(1))->getSymbol();
+      MI->addExternalSymbolOperand(AsmStr);
+      
+      // Add all of the operand registers to the instruction.
+      for (unsigned i = 2; i != NumOps;) {
+        unsigned Flags = cast<ConstantSDNode>(Node->getOperand(i))->getValue();
+        unsigned NumVals = Flags >> 3;
+        
+        MI->addImmOperand(Flags);
+        ++i;  // Skip the ID value.
+        
+        switch (Flags & 7) {
+        default: assert(0 && "Bad flags!");
+        case 1:  // Use of register.
+          for (; NumVals; --NumVals, ++i) {
+            unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
+            MI->addRegOperand(Reg, false);
+          }
+          break;
+        case 2:   // Def of register.
+          for (; NumVals; --NumVals, ++i) {
+            unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
+            MI->addRegOperand(Reg, true);
+          }
+          break;
+        case 3: { // Immediate.
+          assert(NumVals == 1 && "Unknown immediate value!");
+          if (ConstantSDNode *CS=dyn_cast<ConstantSDNode>(Node->getOperand(i))){
+            MI->addImmOperand(CS->getValue());
+          } else {
+            GlobalAddressSDNode *GA = 
+              cast<GlobalAddressSDNode>(Node->getOperand(i));
+            MI->addGlobalAddressOperand(GA->getGlobal(), GA->getOffset());
+          }
+          ++i;
+          break;
+        }
+        case 4:  // Addressing mode.
+          // The addressing mode has been selected, just add all of the
+          // operands to the machine instruction.
+          for (; NumVals; --NumVals, ++i)
+            AddOperand(MI, Node->getOperand(i), 0, 0, VRBaseMap);
+          break;
+        }
+      }
+      break;
+    }
+    }
+  }
+}
+
+void ScheduleDAG::EmitNoop() {
+  TII->insertNoop(*BB, BB->end());
+}
+
+/// EmitSchedule - Emit the machine code in scheduled order.
+void ScheduleDAG::EmitSchedule() {
+  // If this is the first basic block in the function, and if it has live ins
+  // that need to be copied into vregs, emit the copies into the top of the
+  // block before emitting the code for the block.
+  MachineFunction &MF = DAG.getMachineFunction();
+  if (&MF.front() == BB && MF.livein_begin() != MF.livein_end()) {
+    for (MachineFunction::livein_iterator LI = MF.livein_begin(),
+         E = MF.livein_end(); LI != E; ++LI)
+      if (LI->second)
+        MRI->copyRegToReg(*MF.begin(), MF.begin()->end(), LI->second,
+                          LI->first, RegMap->getRegClass(LI->second));
+  }
+  
+  
+  // Finally, emit the code for all of the scheduled instructions.
+  DenseMap<SDOperand, unsigned> VRBaseMap;
+  for (unsigned i = 0, e = Sequence.size(); i != e; i++) {
+    if (SUnit *SU = Sequence[i]) {
+      for (unsigned j = 0, ee = SU->FlaggedNodes.size(); j != ee; j++)
+        EmitNode(SU->FlaggedNodes[j], VRBaseMap);
+      EmitNode(SU->Node, VRBaseMap);
+    } else {
+      // Null SUnit* is a noop.
+      EmitNoop();
+    }
+  }
+}
+
+/// dump - dump the schedule.
+void ScheduleDAG::dumpSchedule() const {
+  for (unsigned i = 0, e = Sequence.size(); i != e; i++) {
+    if (SUnit *SU = Sequence[i])
+      SU->dump(&DAG);
+    else
+      cerr << "**** NOOP ****\n";
+  }
+}
+
+
+/// Run - perform scheduling.
+///
+MachineBasicBlock *ScheduleDAG::Run() {
+  TII = TM.getInstrInfo();
+  MRI = TM.getRegisterInfo();
+  RegMap = BB->getParent()->getSSARegMap();
+  ConstPool = BB->getParent()->getConstantPool();
+
+  Schedule();
+  return BB;
+}
+
+/// SUnit - Scheduling unit. It's an wrapper around either a single SDNode or
+/// a group of nodes flagged together.
+void SUnit::dump(const SelectionDAG *G) const {
+  cerr << "SU(" << NodeNum << "): ";
+  Node->dump(G);
+  cerr << "\n";
+  if (FlaggedNodes.size() != 0) {
+    for (unsigned i = 0, e = FlaggedNodes.size(); i != e; i++) {
+      cerr << "    ";
+      FlaggedNodes[i]->dump(G);
+      cerr << "\n";
+    }
+  }
+}
+
+void SUnit::dumpAll(const SelectionDAG *G) const {
+  dump(G);
+
+  cerr << "  # preds left       : " << NumPredsLeft << "\n";
+  cerr << "  # succs left       : " << NumSuccsLeft << "\n";
+  cerr << "  # chain preds left : " << NumChainPredsLeft << "\n";
+  cerr << "  # chain succs left : " << NumChainSuccsLeft << "\n";
+  cerr << "  Latency            : " << Latency << "\n";
+  cerr << "  Depth              : " << Depth << "\n";
+  cerr << "  Height             : " << Height << "\n";
+
+  if (Preds.size() != 0) {
+    cerr << "  Predecessors:\n";
+    for (SUnit::const_succ_iterator I = Preds.begin(), E = Preds.end();
+         I != E; ++I) {
+      if (I->second)
+        cerr << "   ch  #";
+      else
+        cerr << "   val #";
+      cerr << I->first << " - SU(" << I->first->NodeNum << ")\n";
+    }
+  }
+  if (Succs.size() != 0) {
+    cerr << "  Successors:\n";
+    for (SUnit::const_succ_iterator I = Succs.begin(), E = Succs.end();
+         I != E; ++I) {
+      if (I->second)
+        cerr << "   ch  #";
+      else
+        cerr << "   val #";
+      cerr << I->first << " - SU(" << I->first->NodeNum << ")\n";
+    }
+  }
+  cerr << "\n";
+}