|  | //===---- 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 "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; | 
|  | } | 
|  |  | 
|  | static void CalculateDepths(SUnit &SU, unsigned Depth) { | 
|  | 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) | 
|  | CalculateDepths(*I->first, Depth+1); | 
|  | } | 
|  | } | 
|  |  | 
|  | void ScheduleDAG::CalculateDepths() { | 
|  | SUnit *Entry = SUnitMap[DAG.getEntryNode().Val]; | 
|  | ::CalculateDepths(*Entry, 0U); | 
|  | for (unsigned i = 0, e = SUnits.size(); i != e; ++i) | 
|  | if (SUnits[i].Preds.size() == 0 && &SUnits[i] != Entry) { | 
|  | ::CalculateDepths(SUnits[i], 0U); | 
|  | } | 
|  | } | 
|  |  | 
|  | static void CalculateHeights(SUnit &SU, unsigned Height) { | 
|  | 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) | 
|  | CalculateHeights(*I->first, Height+1); | 
|  | } | 
|  | } | 
|  | void ScheduleDAG::CalculateHeights() { | 
|  | SUnit *Root = SUnitMap[DAG.getRoot().Val]; | 
|  | ::CalculateHeights(*Root, 0U); | 
|  | } | 
|  |  | 
|  | /// 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 unsigned CreateVirtualRegisters(const MRegisterInfo *MRI, | 
|  | MachineInstr *MI, | 
|  | unsigned NumResults, | 
|  | SSARegMap *RegMap, | 
|  | const TargetInstrInfo *TII, | 
|  | const TargetInstrDescriptor &II) { | 
|  | // Create the result registers for this node and add the result regs to | 
|  | // the machine instruction. | 
|  | unsigned ResultReg = | 
|  | RegMap->createVirtualRegister(getInstrOperandRegClass(MRI, TII, &II, 0)); | 
|  | MI->addRegOperand(ResultReg, true); | 
|  | for (unsigned i = 1; i != NumResults; ++i) { | 
|  | const TargetRegisterClass *RC = getInstrOperandRegClass(MRI, TII, &II, i); | 
|  | assert(RC && "Isn't a register operand!"); | 
|  | MI->addRegOperand(RegMap->createVirtualRegister(RC), true); | 
|  | } | 
|  | return ResultReg; | 
|  | } | 
|  |  | 
|  | /// getVR - Return the virtual register corresponding to the specified result | 
|  | /// of the specified node. | 
|  | static unsigned getVR(SDOperand Op, std::map<SDNode*, unsigned> &VRBaseMap) { | 
|  | std::map<SDNode*, unsigned>::iterator I = VRBaseMap.find(Op.Val); | 
|  | assert(I != VRBaseMap.end() && "Node emitted out of order - late"); | 
|  | return I->second + Op.ResNo; | 
|  | } | 
|  |  | 
|  |  | 
|  | /// 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, | 
|  | std::map<SDNode*, 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); | 
|  | 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!"); | 
|  | } | 
|  | } 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()->getTypeAlignmentShift(Type); | 
|  | if (Align == 0) { | 
|  | // Alignment of packed 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!"); | 
|  | } | 
|  | } | 
|  |  | 
|  | } | 
|  |  | 
|  |  | 
|  | /// EmitNode - Generate machine code for an node and needed dependencies. | 
|  | /// | 
|  | void ScheduleDAG::EmitNode(SDNode *Node, | 
|  | std::map<SDNode*, unsigned> &VRBaseMap) { | 
|  | unsigned VRBase = 0;                 // First virtual register for node | 
|  |  | 
|  | // 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 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. | 
|  | if (NumResults == 1) { | 
|  | 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 Reg = cast<RegisterSDNode>(Use->getOperand(1))->getReg(); | 
|  | if (MRegisterInfo::isVirtualRegister(Reg)) { | 
|  | VRBase = Reg; | 
|  | MI->addRegOperand(Reg, true); | 
|  | break; | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // Otherwise, create new virtual registers. | 
|  | if (NumResults && VRBase == 0) | 
|  | VRBase = CreateVirtualRegisters(MRI, MI, NumResults, RegMap, TII, II); | 
|  |  | 
|  | // 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(); | 
|  | #endif | 
|  | assert(0 && "This target-independent node should have been selected!"); | 
|  | case ISD::EntryToken: // fall thru | 
|  | case ISD::TokenFactor: | 
|  | 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? | 
|  | MRI->copyRegToReg(*BB, BB->end(), DestReg, InReg, | 
|  | RegMap->getRegClass(InReg)); | 
|  | break; | 
|  | } | 
|  | case ISD::CopyFromReg: { | 
|  | unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg(); | 
|  | if (MRegisterInfo::isVirtualRegister(SrcReg)) { | 
|  | VRBase = SrcReg;  // Just use the input register directly! | 
|  | 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 { | 
|  |  | 
|  | // 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(Node->getValueType(0)) && | 
|  | (*I)->contains(SrcReg)) { | 
|  | TRC = *I; | 
|  | break; | 
|  | } | 
|  | assert(TRC && "Couldn't find register class for reg copy!"); | 
|  |  | 
|  | // Create the reg, emit the copy. | 
|  | VRBase = RegMap->createVirtualRegister(TRC); | 
|  | } | 
|  | MRI->copyRegToReg(*BB, BB->end(), VRBase, SrcReg, TRC); | 
|  | 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; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | assert(!VRBaseMap.count(Node) && "Node emitted out of order - early"); | 
|  | VRBaseMap[Node] = VRBase; | 
|  | } | 
|  |  | 
|  | 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. | 
|  | std::map<SDNode*, 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"; | 
|  | } |