| //===---- ScheduleDAGEmit.cpp - Emit routines for the ScheduleDAG class ---===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This implements the Emit routines for the ScheduleDAG class, which creates |
| // MachineInstrs according to the computed schedule. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "pre-RA-sched" |
| #include "llvm/CodeGen/ScheduleDAG.h" |
| #include "llvm/CodeGen/MachineConstantPool.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetInstrInfo.h" |
| #include "llvm/Target/TargetLowering.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/MathExtras.h" |
| using namespace llvm; |
| |
| STATISTIC(NumCommutes, "Number of instructions commuted"); |
| |
| namespace { |
| static cl::opt<bool> |
| SchedLiveInCopies("schedule-livein-copies", |
| cl::desc("Schedule copies of livein registers"), |
| cl::init(false)); |
| } |
| |
| /// getInstrOperandRegClass - Return register class of the operand of an |
| /// instruction of the specified TargetInstrDesc. |
| static const TargetRegisterClass* |
| getInstrOperandRegClass(const TargetRegisterInfo *TRI, |
| const TargetInstrInfo *TII, const TargetInstrDesc &II, |
| unsigned Op) { |
| if (Op >= II.getNumOperands()) { |
| assert(II.isVariadic() && "Invalid operand # of instruction"); |
| return NULL; |
| } |
| if (II.OpInfo[Op].isLookupPtrRegClass()) |
| return TII->getPointerRegClass(); |
| return TRI->getRegClass(II.OpInfo[Op].RegClass); |
| } |
| |
| /// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an |
| /// implicit physical register output. |
| void ScheduleDAG::EmitCopyFromReg(SDNode *Node, unsigned ResNo, |
| bool IsClone, unsigned SrcReg, |
| DenseMap<SDValue, unsigned> &VRBaseMap) { |
| unsigned VRBase = 0; |
| if (TargetRegisterInfo::isVirtualRegister(SrcReg)) { |
| // Just use the input register directly! |
| SDValue Op(Node, ResNo); |
| if (IsClone) |
| VRBaseMap.erase(Op); |
| bool isNew = VRBaseMap.insert(std::make_pair(Op, SrcReg)).second; |
| isNew = isNew; // Silence compiler warning. |
| assert(isNew && "Node emitted out of order - early"); |
| return; |
| } |
| |
| // 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. |
| bool MatchReg = true; |
| for (SDNode::use_iterator UI = Node->use_begin(), E = Node->use_end(); |
| UI != E; ++UI) { |
| SDNode *User = *UI; |
| bool Match = true; |
| if (User->getOpcode() == ISD::CopyToReg && |
| User->getOperand(2).getNode() == Node && |
| User->getOperand(2).getResNo() == ResNo) { |
| unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg(); |
| if (TargetRegisterInfo::isVirtualRegister(DestReg)) { |
| VRBase = DestReg; |
| Match = false; |
| } else if (DestReg != SrcReg) |
| Match = false; |
| } else { |
| for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) { |
| SDValue Op = User->getOperand(i); |
| if (Op.getNode() != Node || Op.getResNo() != ResNo) |
| continue; |
| MVT VT = Node->getValueType(Op.getResNo()); |
| if (VT != MVT::Other && VT != MVT::Flag) |
| Match = false; |
| } |
| } |
| MatchReg &= Match; |
| if (VRBase) |
| break; |
| } |
| |
| const TargetRegisterClass *SrcRC = 0, *DstRC = 0; |
| SrcRC = TRI->getPhysicalRegisterRegClass(SrcReg, Node->getValueType(ResNo)); |
| |
| // Figure out the register class to create for the destreg. |
| if (VRBase) { |
| DstRC = MRI.getRegClass(VRBase); |
| } else { |
| DstRC = TLI->getRegClassFor(Node->getValueType(ResNo)); |
| } |
| |
| // If all uses are reading from the src physical register and copying the |
| // register is either impossible or very expensive, then don't create a copy. |
| if (MatchReg && SrcRC->getCopyCost() < 0) { |
| VRBase = SrcReg; |
| } else { |
| // Create the reg, emit the copy. |
| VRBase = MRI.createVirtualRegister(DstRC); |
| TII->copyRegToReg(*BB, BB->end(), VRBase, SrcReg, DstRC, SrcRC); |
| } |
| |
| SDValue Op(Node, ResNo); |
| if (IsClone) |
| VRBaseMap.erase(Op); |
| bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second; |
| isNew = isNew; // Silence compiler warning. |
| assert(isNew && "Node emitted out of order - early"); |
| } |
| |
| /// getDstOfCopyToRegUse - If the only use of the specified result number of |
| /// node is a CopyToReg, return its destination register. Return 0 otherwise. |
| unsigned ScheduleDAG::getDstOfOnlyCopyToRegUse(SDNode *Node, |
| unsigned ResNo) const { |
| if (!Node->hasOneUse()) |
| return 0; |
| |
| SDNode *User = *Node->use_begin(); |
| if (User->getOpcode() == ISD::CopyToReg && |
| User->getOperand(2).getNode() == Node && |
| User->getOperand(2).getResNo() == ResNo) { |
| unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg(); |
| if (TargetRegisterInfo::isVirtualRegister(Reg)) |
| return Reg; |
| } |
| return 0; |
| } |
| |
| void ScheduleDAG::CreateVirtualRegisters(SDNode *Node, MachineInstr *MI, |
| const TargetInstrDesc &II, |
| DenseMap<SDValue, unsigned> &VRBaseMap) { |
| assert(Node->getMachineOpcode() != TargetInstrInfo::IMPLICIT_DEF && |
| "IMPLICIT_DEF should have been handled as a special case elsewhere!"); |
| |
| for (unsigned i = 0; i < II.getNumDefs(); ++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 *User = *UI; |
| if (User->getOpcode() == ISD::CopyToReg && |
| User->getOperand(2).getNode() == Node && |
| User->getOperand(2).getResNo() == i) { |
| unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg(); |
| if (TargetRegisterInfo::isVirtualRegister(Reg)) { |
| VRBase = Reg; |
| MI->addOperand(MachineOperand::CreateReg(Reg, true)); |
| break; |
| } |
| } |
| } |
| |
| // Create the result registers for this node and add the result regs to |
| // the machine instruction. |
| if (VRBase == 0) { |
| const TargetRegisterClass *RC = getInstrOperandRegClass(TRI, TII, II, i); |
| assert(RC && "Isn't a register operand!"); |
| VRBase = MRI.createVirtualRegister(RC); |
| MI->addOperand(MachineOperand::CreateReg(VRBase, true)); |
| } |
| |
| SDValue Op(Node, i); |
| bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second; |
| isNew = isNew; // Silence compiler warning. |
| assert(isNew && "Node emitted out of order - early"); |
| } |
| } |
| |
| /// getVR - Return the virtual register corresponding to the specified result |
| /// of the specified node. |
| unsigned ScheduleDAG::getVR(SDValue Op, |
| DenseMap<SDValue, unsigned> &VRBaseMap) { |
| if (Op.isMachineOpcode() && |
| Op.getMachineOpcode() == TargetInstrInfo::IMPLICIT_DEF) { |
| // Add an IMPLICIT_DEF instruction before every use. |
| unsigned VReg = getDstOfOnlyCopyToRegUse(Op.getNode(), Op.getResNo()); |
| // IMPLICIT_DEF can produce any type of result so its TargetInstrDesc |
| // does not include operand register class info. |
| if (!VReg) { |
| const TargetRegisterClass *RC = TLI->getRegClassFor(Op.getValueType()); |
| VReg = MRI.createVirtualRegister(RC); |
| } |
| BuildMI(BB, TII->get(TargetInstrInfo::IMPLICIT_DEF), VReg); |
| return VReg; |
| } |
| |
| DenseMap<SDValue, 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, SDValue Op, |
| unsigned IIOpNum, |
| const TargetInstrDesc *II, |
| DenseMap<SDValue, unsigned> &VRBaseMap) { |
| if (Op.isMachineOpcode()) { |
| // 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 TargetInstrDesc &TID = MI->getDesc(); |
| bool isOptDef = IIOpNum < TID.getNumOperands() && |
| TID.OpInfo[IIOpNum].isOptionalDef(); |
| MI->addOperand(MachineOperand::CreateReg(VReg, isOptDef)); |
| |
| // Verify that it is right. |
| assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?"); |
| #ifndef NDEBUG |
| if (II) { |
| // There may be no register class for this operand if it is a variadic |
| // argument (RC will be NULL in this case). In this case, we just assume |
| // the regclass is ok. |
| const TargetRegisterClass *RC = |
| getInstrOperandRegClass(TRI, TII, *II, IIOpNum); |
| assert((RC || II->isVariadic()) && "Expected reg class info!"); |
| const TargetRegisterClass *VRC = MRI.getRegClass(VReg); |
| if (RC && VRC != RC) { |
| cerr << "Register class of operand and regclass of use don't agree!\n"; |
| cerr << "Operand = " << IIOpNum << "\n"; |
| cerr << "Op->Val = "; Op.getNode()->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"; |
| cerr << "Fatal error, aborting.\n"; |
| abort(); |
| } |
| } |
| #endif |
| } else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateImm(C->getValue())); |
| } else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) { |
| ConstantFP *CFP = ConstantFP::get(F->getValueAPF()); |
| MI->addOperand(MachineOperand::CreateFPImm(CFP)); |
| } else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateReg(R->getReg(), false)); |
| } else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateGA(TGA->getGlobal(),TGA->getOffset())); |
| } else if (BasicBlockSDNode *BB = dyn_cast<BasicBlockSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateMBB(BB->getBasicBlock())); |
| } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateFI(FI->getIndex())); |
| } else if (JumpTableSDNode *JT = dyn_cast<JumpTableSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateJTI(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()->getABITypeSize(Type); |
| Align = Log2_64(Align); |
| } |
| } |
| |
| unsigned Idx; |
| if (CP->isMachineConstantPoolEntry()) |
| Idx = ConstPool->getConstantPoolIndex(CP->getMachineCPVal(), Align); |
| else |
| Idx = ConstPool->getConstantPoolIndex(CP->getConstVal(), Align); |
| MI->addOperand(MachineOperand::CreateCPI(Idx, Offset)); |
| } else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) { |
| MI->addOperand(MachineOperand::CreateES(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->addOperand(MachineOperand::CreateReg(VReg, false)); |
| |
| // Verify that it is right. Note that the reg class of the physreg and the |
| // vreg don't necessarily need to match, but the target copy insertion has |
| // to be able to handle it. This handles things like copies from ST(0) to |
| // an FP vreg on x86. |
| assert(TargetRegisterInfo::isVirtualRegister(VReg) && "Not a vreg?"); |
| if (II && !II->isVariadic()) { |
| assert(getInstrOperandRegClass(TRI, TII, *II, IIOpNum) && |
| "Don't have operand info for this instruction!"); |
| } |
| } |
| } |
| |
| void ScheduleDAG::AddMemOperand(MachineInstr *MI, const MachineMemOperand &MO) { |
| MI->addMemOperand(*MF, MO); |
| } |
| |
| /// getSubRegisterRegClass - Returns the register class of specified register |
| /// class' "SubIdx"'th sub-register class. |
| static const TargetRegisterClass* |
| getSubRegisterRegClass(const TargetRegisterClass *TRC, unsigned SubIdx) { |
| // Pick the register class of the subregister |
| TargetRegisterInfo::regclass_iterator I = |
| TRC->subregclasses_begin() + SubIdx-1; |
| assert(I < TRC->subregclasses_end() && |
| "Invalid subregister index for register class"); |
| return *I; |
| } |
| |
| /// getSuperRegisterRegClass - Returns the register class of a superreg A whose |
| /// "SubIdx"'th sub-register class is the specified register class and whose |
| /// type matches the specified type. |
| static const TargetRegisterClass* |
| getSuperRegisterRegClass(const TargetRegisterClass *TRC, |
| unsigned SubIdx, MVT VT) { |
| // Pick the register class of the superegister for this type |
| for (TargetRegisterInfo::regclass_iterator I = TRC->superregclasses_begin(), |
| E = TRC->superregclasses_end(); I != E; ++I) |
| if ((*I)->hasType(VT) && getSubRegisterRegClass(*I, SubIdx) == TRC) |
| return *I; |
| assert(false && "Couldn't find the register class"); |
| return 0; |
| } |
| |
| /// EmitSubregNode - Generate machine code for subreg nodes. |
| /// |
| void ScheduleDAG::EmitSubregNode(SDNode *Node, |
| DenseMap<SDValue, unsigned> &VRBaseMap) { |
| unsigned VRBase = 0; |
| unsigned Opc = Node->getMachineOpcode(); |
| |
| // 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 *User = *UI; |
| if (User->getOpcode() == ISD::CopyToReg && |
| User->getOperand(2).getNode() == Node) { |
| unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg(); |
| if (TargetRegisterInfo::isVirtualRegister(DestReg)) { |
| VRBase = DestReg; |
| break; |
| } |
| } |
| } |
| |
| if (Opc == TargetInstrInfo::EXTRACT_SUBREG) { |
| unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getValue(); |
| |
| // Create the extract_subreg machine instruction. |
| MachineInstr *MI = BuildMI(*MF, TII->get(TargetInstrInfo::EXTRACT_SUBREG)); |
| |
| // Figure out the register class to create for the destreg. |
| unsigned VReg = getVR(Node->getOperand(0), VRBaseMap); |
| const TargetRegisterClass *TRC = MRI.getRegClass(VReg); |
| const TargetRegisterClass *SRC = getSubRegisterRegClass(TRC, SubIdx); |
| |
| if (VRBase) { |
| // Grab the destination register |
| #ifndef NDEBUG |
| const TargetRegisterClass *DRC = MRI.getRegClass(VRBase); |
| assert(SRC && DRC && SRC == DRC && |
| "Source subregister and destination must have the same class"); |
| #endif |
| } else { |
| // Create the reg |
| assert(SRC && "Couldn't find source register class"); |
| VRBase = MRI.createVirtualRegister(SRC); |
| } |
| |
| // Add def, source, and subreg index |
| MI->addOperand(MachineOperand::CreateReg(VRBase, true)); |
| AddOperand(MI, Node->getOperand(0), 0, 0, VRBaseMap); |
| MI->addOperand(MachineOperand::CreateImm(SubIdx)); |
| BB->push_back(MI); |
| } else if (Opc == TargetInstrInfo::INSERT_SUBREG || |
| Opc == TargetInstrInfo::SUBREG_TO_REG) { |
| SDValue N0 = Node->getOperand(0); |
| SDValue N1 = Node->getOperand(1); |
| SDValue N2 = Node->getOperand(2); |
| unsigned SubReg = getVR(N1, VRBaseMap); |
| unsigned SubIdx = cast<ConstantSDNode>(N2)->getValue(); |
| |
| |
| // Figure out the register class to create for the destreg. |
| const TargetRegisterClass *TRC = 0; |
| if (VRBase) { |
| TRC = MRI.getRegClass(VRBase); |
| } else { |
| TRC = getSuperRegisterRegClass(MRI.getRegClass(SubReg), SubIdx, |
| Node->getValueType(0)); |
| assert(TRC && "Couldn't determine register class for insert_subreg"); |
| VRBase = MRI.createVirtualRegister(TRC); // Create the reg |
| } |
| |
| // Create the insert_subreg or subreg_to_reg machine instruction. |
| MachineInstr *MI = BuildMI(*MF, TII->get(Opc)); |
| MI->addOperand(MachineOperand::CreateReg(VRBase, true)); |
| |
| // If creating a subreg_to_reg, then the first input operand |
| // is an implicit value immediate, otherwise it's a register |
| if (Opc == TargetInstrInfo::SUBREG_TO_REG) { |
| const ConstantSDNode *SD = cast<ConstantSDNode>(N0); |
| MI->addOperand(MachineOperand::CreateImm(SD->getValue())); |
| } else |
| AddOperand(MI, N0, 0, 0, VRBaseMap); |
| // Add the subregster being inserted |
| AddOperand(MI, N1, 0, 0, VRBaseMap); |
| MI->addOperand(MachineOperand::CreateImm(SubIdx)); |
| BB->push_back(MI); |
| } else |
| assert(0 && "Node is not insert_subreg, extract_subreg, or subreg_to_reg"); |
| |
| SDValue Op(Node, 0); |
| bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second; |
| isNew = isNew; // Silence compiler warning. |
| assert(isNew && "Node emitted out of order - early"); |
| } |
| |
| /// EmitNode - Generate machine code for an node and needed dependencies. |
| /// |
| void ScheduleDAG::EmitNode(SDNode *Node, bool IsClone, |
| DenseMap<SDValue, unsigned> &VRBaseMap) { |
| // If machine instruction |
| if (Node->isMachineOpcode()) { |
| unsigned Opc = Node->getMachineOpcode(); |
| |
| // Handle subreg insert/extract specially |
| if (Opc == TargetInstrInfo::EXTRACT_SUBREG || |
| Opc == TargetInstrInfo::INSERT_SUBREG || |
| Opc == TargetInstrInfo::SUBREG_TO_REG) { |
| EmitSubregNode(Node, VRBaseMap); |
| return; |
| } |
| |
| if (Opc == TargetInstrInfo::IMPLICIT_DEF) |
| // We want a unique VR for each IMPLICIT_DEF use. |
| return; |
| |
| const TargetInstrDesc &II = TII->get(Opc); |
| unsigned NumResults = CountResults(Node); |
| unsigned NodeOperands = CountOperands(Node); |
| unsigned MemOperandsEnd = ComputeMemOperandsEnd(Node); |
| bool HasPhysRegOuts = (NumResults > II.getNumDefs()) && |
| II.getImplicitDefs() != 0; |
| #ifndef NDEBUG |
| unsigned NumMIOperands = NodeOperands + NumResults; |
| assert((II.getNumOperands() == NumMIOperands || |
| HasPhysRegOuts || II.isVariadic()) && |
| "#operands for dag node doesn't match .td file!"); |
| #endif |
| |
| // Create the new machine instruction. |
| MachineInstr *MI = BuildMI(*MF, II); |
| |
| // Add result register values for things that are defined by this |
| // instruction. |
| if (NumResults) |
| CreateVirtualRegisters(Node, MI, 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+II.getNumDefs(), &II, VRBaseMap); |
| |
| // Emit all of the memory operands of this instruction |
| for (unsigned i = NodeOperands; i != MemOperandsEnd; ++i) |
| AddMemOperand(MI, cast<MemOperandSDNode>(Node->getOperand(i))->MO); |
| |
| // 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) { |
| MF->DeleteMachineInstr(MI); |
| MI = NewMI; |
| } |
| ++NumCommutes; |
| } |
| } |
| |
| if (II.usesCustomDAGSchedInsertionHook()) |
| // Insert this instruction into the basic block using a target |
| // specific inserter which may returns a new basic block. |
| BB = TLI->EmitInstrWithCustomInserter(MI, BB); |
| else |
| BB->push_back(MI); |
| |
| // Additional results must be an physical register def. |
| if (HasPhysRegOuts) { |
| for (unsigned i = II.getNumDefs(); i < NumResults; ++i) { |
| unsigned Reg = II.getImplicitDefs()[i - II.getNumDefs()]; |
| if (Node->hasAnyUseOfValue(i)) |
| EmitCopyFromReg(Node, i, IsClone, Reg, VRBaseMap); |
| } |
| } |
| return; |
| } |
| |
| switch (Node->getOpcode()) { |
| default: |
| #ifndef NDEBUG |
| Node->dump(&DAG); |
| #endif |
| assert(0 && "This target-independent node should have been selected!"); |
| break; |
| case ISD::EntryToken: |
| assert(0 && "EntryToken should have been excluded from the schedule!"); |
| break; |
| case ISD::TokenFactor: // fall thru |
| break; |
| case ISD::CopyToReg: { |
| unsigned SrcReg; |
| SDValue SrcVal = Node->getOperand(2); |
| if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(SrcVal)) |
| SrcReg = R->getReg(); |
| else |
| SrcReg = getVR(SrcVal, VRBaseMap); |
| |
| unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg(); |
| if (SrcReg == DestReg) // Coalesced away the copy? Ignore. |
| break; |
| |
| const TargetRegisterClass *SrcTRC = 0, *DstTRC = 0; |
| // Get the register classes of the src/dst. |
| if (TargetRegisterInfo::isVirtualRegister(SrcReg)) |
| SrcTRC = MRI.getRegClass(SrcReg); |
| else |
| SrcTRC = TRI->getPhysicalRegisterRegClass(SrcReg,SrcVal.getValueType()); |
| |
| if (TargetRegisterInfo::isVirtualRegister(DestReg)) |
| DstTRC = MRI.getRegClass(DestReg); |
| else |
| DstTRC = TRI->getPhysicalRegisterRegClass(DestReg, |
| Node->getOperand(1).getValueType()); |
| TII->copyRegToReg(*BB, BB->end(), DestReg, SrcReg, DstTRC, SrcTRC); |
| break; |
| } |
| case ISD::CopyFromReg: { |
| unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg(); |
| EmitCopyFromReg(Node, 0, IsClone, SrcReg, VRBaseMap); |
| 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 = BuildMI(*MF, TII->get(TargetInstrInfo::INLINEASM)); |
| |
| // Add the asm string as an external symbol operand. |
| const char *AsmStr = |
| cast<ExternalSymbolSDNode>(Node->getOperand(1))->getSymbol(); |
| MI->addOperand(MachineOperand::CreateES(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->addOperand(MachineOperand::CreateImm(Flags)); |
| ++i; // Skip the ID value. |
| |
| switch (Flags & 7) { |
| default: assert(0 && "Bad flags!"); |
| case 2: // Def of register. |
| for (; NumVals; --NumVals, ++i) { |
| unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg(); |
| MI->addOperand(MachineOperand::CreateReg(Reg, true)); |
| } |
| break; |
| case 1: // Use of register. |
| case 3: // Immediate. |
| 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; |
| } |
| } |
| BB->push_back(MI); |
| break; |
| } |
| } |
| } |
| |
| void ScheduleDAG::EmitNoop() { |
| TII->insertNoop(*BB, BB->end()); |
| } |
| |
| void ScheduleDAG::EmitCrossRCCopy(SUnit *SU, |
| DenseMap<SUnit*, unsigned> &VRBaseMap) { |
| for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end(); |
| I != E; ++I) { |
| if (I->isCtrl) continue; // ignore chain preds |
| if (!I->Dep->Node) { |
| // Copy to physical register. |
| DenseMap<SUnit*, unsigned>::iterator VRI = VRBaseMap.find(I->Dep); |
| assert(VRI != VRBaseMap.end() && "Node emitted out of order - late"); |
| // Find the destination physical register. |
| unsigned Reg = 0; |
| for (SUnit::const_succ_iterator II = SU->Succs.begin(), |
| EE = SU->Succs.end(); II != EE; ++II) { |
| if (I->Reg) { |
| Reg = I->Reg; |
| break; |
| } |
| } |
| assert(I->Reg && "Unknown physical register!"); |
| TII->copyRegToReg(*BB, BB->end(), Reg, VRI->second, |
| SU->CopyDstRC, SU->CopySrcRC); |
| } else { |
| // Copy from physical register. |
| assert(I->Reg && "Unknown physical register!"); |
| unsigned VRBase = MRI.createVirtualRegister(SU->CopyDstRC); |
| bool isNew = VRBaseMap.insert(std::make_pair(SU, VRBase)).second; |
| isNew = isNew; // Silence compiler warning. |
| assert(isNew && "Node emitted out of order - early"); |
| TII->copyRegToReg(*BB, BB->end(), VRBase, I->Reg, |
| SU->CopyDstRC, SU->CopySrcRC); |
| } |
| break; |
| } |
| } |
| |
| /// EmitLiveInCopy - Emit a copy for a live in physical register. If the |
| /// physical register has only a single copy use, then coalesced the copy |
| /// if possible. |
| void ScheduleDAG::EmitLiveInCopy(MachineBasicBlock *MBB, |
| MachineBasicBlock::iterator &InsertPos, |
| unsigned VirtReg, unsigned PhysReg, |
| const TargetRegisterClass *RC, |
| DenseMap<MachineInstr*, unsigned> &CopyRegMap){ |
| unsigned NumUses = 0; |
| MachineInstr *UseMI = NULL; |
| for (MachineRegisterInfo::use_iterator UI = MRI.use_begin(VirtReg), |
| UE = MRI.use_end(); UI != UE; ++UI) { |
| UseMI = &*UI; |
| if (++NumUses > 1) |
| break; |
| } |
| |
| // If the number of uses is not one, or the use is not a move instruction, |
| // don't coalesce. Also, only coalesce away a virtual register to virtual |
| // register copy. |
| bool Coalesced = false; |
| unsigned SrcReg, DstReg; |
| if (NumUses == 1 && |
| TII->isMoveInstr(*UseMI, SrcReg, DstReg) && |
| TargetRegisterInfo::isVirtualRegister(DstReg)) { |
| VirtReg = DstReg; |
| Coalesced = true; |
| } |
| |
| // Now find an ideal location to insert the copy. |
| MachineBasicBlock::iterator Pos = InsertPos; |
| while (Pos != MBB->begin()) { |
| MachineInstr *PrevMI = prior(Pos); |
| DenseMap<MachineInstr*, unsigned>::iterator RI = CopyRegMap.find(PrevMI); |
| // copyRegToReg might emit multiple instructions to do a copy. |
| unsigned CopyDstReg = (RI == CopyRegMap.end()) ? 0 : RI->second; |
| if (CopyDstReg && !TRI->regsOverlap(CopyDstReg, PhysReg)) |
| // This is what the BB looks like right now: |
| // r1024 = mov r0 |
| // ... |
| // r1 = mov r1024 |
| // |
| // We want to insert "r1025 = mov r1". Inserting this copy below the |
| // move to r1024 makes it impossible for that move to be coalesced. |
| // |
| // r1025 = mov r1 |
| // r1024 = mov r0 |
| // ... |
| // r1 = mov 1024 |
| // r2 = mov 1025 |
| break; // Woot! Found a good location. |
| --Pos; |
| } |
| |
| TII->copyRegToReg(*MBB, Pos, VirtReg, PhysReg, RC, RC); |
| CopyRegMap.insert(std::make_pair(prior(Pos), VirtReg)); |
| if (Coalesced) { |
| if (&*InsertPos == UseMI) ++InsertPos; |
| MBB->erase(UseMI); |
| } |
| } |
| |
| /// EmitLiveInCopies - 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. |
| void ScheduleDAG::EmitLiveInCopies(MachineBasicBlock *MBB) { |
| DenseMap<MachineInstr*, unsigned> CopyRegMap; |
| MachineBasicBlock::iterator InsertPos = MBB->begin(); |
| for (MachineRegisterInfo::livein_iterator LI = MRI.livein_begin(), |
| E = MRI.livein_end(); LI != E; ++LI) |
| if (LI->second) { |
| const TargetRegisterClass *RC = MRI.getRegClass(LI->second); |
| EmitLiveInCopy(MBB, InsertPos, LI->second, LI->first, RC, CopyRegMap); |
| } |
| } |
| |
| /// EmitSchedule - Emit the machine code in scheduled order. |
| MachineBasicBlock *ScheduleDAG::EmitSchedule() { |
| bool isEntryBB = &MF->front() == BB; |
| |
| if (isEntryBB && !SchedLiveInCopies) { |
| // 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. |
| for (MachineRegisterInfo::livein_iterator LI = MRI.livein_begin(), |
| E = MRI.livein_end(); LI != E; ++LI) |
| if (LI->second) { |
| const TargetRegisterClass *RC = MRI.getRegClass(LI->second); |
| TII->copyRegToReg(*MF->begin(), MF->begin()->end(), LI->second, |
| LI->first, RC, RC); |
| } |
| } |
| |
| // Finally, emit the code for all of the scheduled instructions. |
| DenseMap<SDValue, unsigned> VRBaseMap; |
| DenseMap<SUnit*, unsigned> CopyVRBaseMap; |
| for (unsigned i = 0, e = Sequence.size(); i != e; i++) { |
| SUnit *SU = Sequence[i]; |
| if (!SU) { |
| // Null SUnit* is a noop. |
| EmitNoop(); |
| continue; |
| } |
| for (unsigned j = 0, ee = SU->FlaggedNodes.size(); j != ee; ++j) |
| EmitNode(SU->FlaggedNodes[j], SU->OrigNode != SU, VRBaseMap); |
| if (!SU->Node) |
| EmitCrossRCCopy(SU, CopyVRBaseMap); |
| else |
| EmitNode(SU->Node, SU->OrigNode != SU, VRBaseMap); |
| } |
| |
| if (isEntryBB && SchedLiveInCopies) |
| EmitLiveInCopies(MF->begin()); |
| |
| return BB; |
| } |