| //===-- ARMLoadStoreOptimizer.cpp - ARM load / store opt. pass ----*- C++ -*-=// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains a pass that performs load / store related peephole |
| // optimizations. This pass should be run after register allocation. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "arm-ldst-opt" |
| #include "ARM.h" |
| #include "ARMBaseInstrInfo.h" |
| #include "ARMMachineFunctionInfo.h" |
| #include "ARMRegisterInfo.h" |
| #include "MCTargetDesc/ARMAddressingModes.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/Function.h" |
| #include "llvm/CodeGen/MachineBasicBlock.h" |
| #include "llvm/CodeGen/MachineFunctionPass.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/CodeGen/RegisterScavenging.h" |
| #include "llvm/CodeGen/SelectionDAGNodes.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Target/TargetInstrInfo.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetRegisterInfo.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/Statistic.h" |
| using namespace llvm; |
| |
| STATISTIC(NumLDMGened , "Number of ldm instructions generated"); |
| STATISTIC(NumSTMGened , "Number of stm instructions generated"); |
| STATISTIC(NumVLDMGened, "Number of vldm instructions generated"); |
| STATISTIC(NumVSTMGened, "Number of vstm instructions generated"); |
| STATISTIC(NumLdStMoved, "Number of load / store instructions moved"); |
| STATISTIC(NumLDRDFormed,"Number of ldrd created before allocation"); |
| STATISTIC(NumSTRDFormed,"Number of strd created before allocation"); |
| STATISTIC(NumLDRD2LDM, "Number of ldrd instructions turned back into ldm"); |
| STATISTIC(NumSTRD2STM, "Number of strd instructions turned back into stm"); |
| STATISTIC(NumLDRD2LDR, "Number of ldrd instructions turned back into ldr's"); |
| STATISTIC(NumSTRD2STR, "Number of strd instructions turned back into str's"); |
| |
| /// ARMAllocLoadStoreOpt - Post- register allocation pass the combine |
| /// load / store instructions to form ldm / stm instructions. |
| |
| namespace { |
| struct ARMLoadStoreOpt : public MachineFunctionPass { |
| static char ID; |
| ARMLoadStoreOpt() : MachineFunctionPass(ID) {} |
| |
| const TargetInstrInfo *TII; |
| const TargetRegisterInfo *TRI; |
| const ARMSubtarget *STI; |
| ARMFunctionInfo *AFI; |
| RegScavenger *RS; |
| bool isThumb2; |
| |
| virtual bool runOnMachineFunction(MachineFunction &Fn); |
| |
| virtual const char *getPassName() const { |
| return "ARM load / store optimization pass"; |
| } |
| |
| private: |
| struct MemOpQueueEntry { |
| int Offset; |
| unsigned Reg; |
| bool isKill; |
| unsigned Position; |
| MachineBasicBlock::iterator MBBI; |
| bool Merged; |
| MemOpQueueEntry(int o, unsigned r, bool k, unsigned p, |
| MachineBasicBlock::iterator i) |
| : Offset(o), Reg(r), isKill(k), Position(p), MBBI(i), Merged(false) {} |
| }; |
| typedef SmallVector<MemOpQueueEntry,8> MemOpQueue; |
| typedef MemOpQueue::iterator MemOpQueueIter; |
| |
| bool MergeOps(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, |
| int Offset, unsigned Base, bool BaseKill, int Opcode, |
| ARMCC::CondCodes Pred, unsigned PredReg, unsigned Scratch, |
| DebugLoc dl, SmallVector<std::pair<unsigned, bool>, 8> &Regs); |
| void MergeOpsUpdate(MachineBasicBlock &MBB, |
| MemOpQueue &MemOps, |
| unsigned memOpsBegin, |
| unsigned memOpsEnd, |
| unsigned insertAfter, |
| int Offset, |
| unsigned Base, |
| bool BaseKill, |
| int Opcode, |
| ARMCC::CondCodes Pred, |
| unsigned PredReg, |
| unsigned Scratch, |
| DebugLoc dl, |
| SmallVector<MachineBasicBlock::iterator, 4> &Merges); |
| void MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex, unsigned Base, |
| int Opcode, unsigned Size, |
| ARMCC::CondCodes Pred, unsigned PredReg, |
| unsigned Scratch, MemOpQueue &MemOps, |
| SmallVector<MachineBasicBlock::iterator, 4> &Merges); |
| |
| void AdvanceRS(MachineBasicBlock &MBB, MemOpQueue &MemOps); |
| bool FixInvalidRegPairOp(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator &MBBI); |
| bool MergeBaseUpdateLoadStore(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| const TargetInstrInfo *TII, |
| bool &Advance, |
| MachineBasicBlock::iterator &I); |
| bool MergeBaseUpdateLSMultiple(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| bool &Advance, |
| MachineBasicBlock::iterator &I); |
| bool LoadStoreMultipleOpti(MachineBasicBlock &MBB); |
| bool MergeReturnIntoLDM(MachineBasicBlock &MBB); |
| }; |
| char ARMLoadStoreOpt::ID = 0; |
| } |
| |
| static int getLoadStoreMultipleOpcode(int Opcode, ARM_AM::AMSubMode Mode) { |
| switch (Opcode) { |
| default: llvm_unreachable("Unhandled opcode!"); |
| case ARM::LDRi12: |
| ++NumLDMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::LDMIA; |
| case ARM_AM::da: return ARM::LDMDA; |
| case ARM_AM::db: return ARM::LDMDB; |
| case ARM_AM::ib: return ARM::LDMIB; |
| } |
| break; |
| case ARM::STRi12: |
| ++NumSTMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::STMIA; |
| case ARM_AM::da: return ARM::STMDA; |
| case ARM_AM::db: return ARM::STMDB; |
| case ARM_AM::ib: return ARM::STMIB; |
| } |
| break; |
| case ARM::t2LDRi8: |
| case ARM::t2LDRi12: |
| ++NumLDMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::t2LDMIA; |
| case ARM_AM::db: return ARM::t2LDMDB; |
| } |
| break; |
| case ARM::t2STRi8: |
| case ARM::t2STRi12: |
| ++NumSTMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::t2STMIA; |
| case ARM_AM::db: return ARM::t2STMDB; |
| } |
| break; |
| case ARM::VLDRS: |
| ++NumVLDMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VLDMSIA; |
| case ARM_AM::db: return 0; // Only VLDMSDB_UPD exists. |
| } |
| break; |
| case ARM::VSTRS: |
| ++NumVSTMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VSTMSIA; |
| case ARM_AM::db: return 0; // Only VSTMSDB_UPD exists. |
| } |
| break; |
| case ARM::VLDRD: |
| ++NumVLDMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VLDMDIA; |
| case ARM_AM::db: return 0; // Only VLDMDDB_UPD exists. |
| } |
| break; |
| case ARM::VSTRD: |
| ++NumVSTMGened; |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VSTMDIA; |
| case ARM_AM::db: return 0; // Only VSTMDDB_UPD exists. |
| } |
| break; |
| } |
| |
| return 0; |
| } |
| |
| namespace llvm { |
| namespace ARM_AM { |
| |
| AMSubMode getLoadStoreMultipleSubMode(int Opcode) { |
| switch (Opcode) { |
| default: llvm_unreachable("Unhandled opcode!"); |
| case ARM::LDMIA_RET: |
| case ARM::LDMIA: |
| case ARM::LDMIA_UPD: |
| case ARM::STMIA: |
| case ARM::STMIA_UPD: |
| case ARM::t2LDMIA_RET: |
| case ARM::t2LDMIA: |
| case ARM::t2LDMIA_UPD: |
| case ARM::t2STMIA: |
| case ARM::t2STMIA_UPD: |
| case ARM::VLDMSIA: |
| case ARM::VLDMSIA_UPD: |
| case ARM::VSTMSIA: |
| case ARM::VSTMSIA_UPD: |
| case ARM::VLDMDIA: |
| case ARM::VLDMDIA_UPD: |
| case ARM::VSTMDIA: |
| case ARM::VSTMDIA_UPD: |
| return ARM_AM::ia; |
| |
| case ARM::LDMDA: |
| case ARM::LDMDA_UPD: |
| case ARM::STMDA: |
| case ARM::STMDA_UPD: |
| return ARM_AM::da; |
| |
| case ARM::LDMDB: |
| case ARM::LDMDB_UPD: |
| case ARM::STMDB: |
| case ARM::STMDB_UPD: |
| case ARM::t2LDMDB: |
| case ARM::t2LDMDB_UPD: |
| case ARM::t2STMDB: |
| case ARM::t2STMDB_UPD: |
| case ARM::VLDMSDB_UPD: |
| case ARM::VSTMSDB_UPD: |
| case ARM::VLDMDDB_UPD: |
| case ARM::VSTMDDB_UPD: |
| return ARM_AM::db; |
| |
| case ARM::LDMIB: |
| case ARM::LDMIB_UPD: |
| case ARM::STMIB: |
| case ARM::STMIB_UPD: |
| return ARM_AM::ib; |
| } |
| |
| return ARM_AM::bad_am_submode; |
| } |
| |
| } // end namespace ARM_AM |
| } // end namespace llvm |
| |
| static bool isT2i32Load(unsigned Opc) { |
| return Opc == ARM::t2LDRi12 || Opc == ARM::t2LDRi8; |
| } |
| |
| static bool isi32Load(unsigned Opc) { |
| return Opc == ARM::LDRi12 || isT2i32Load(Opc); |
| } |
| |
| static bool isT2i32Store(unsigned Opc) { |
| return Opc == ARM::t2STRi12 || Opc == ARM::t2STRi8; |
| } |
| |
| static bool isi32Store(unsigned Opc) { |
| return Opc == ARM::STRi12 || isT2i32Store(Opc); |
| } |
| |
| /// MergeOps - Create and insert a LDM or STM with Base as base register and |
| /// registers in Regs as the register operands that would be loaded / stored. |
| /// It returns true if the transformation is done. |
| bool |
| ARMLoadStoreOpt::MergeOps(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| int Offset, unsigned Base, bool BaseKill, |
| int Opcode, ARMCC::CondCodes Pred, |
| unsigned PredReg, unsigned Scratch, DebugLoc dl, |
| SmallVector<std::pair<unsigned, bool>, 8> &Regs) { |
| // Only a single register to load / store. Don't bother. |
| unsigned NumRegs = Regs.size(); |
| if (NumRegs <= 1) |
| return false; |
| |
| ARM_AM::AMSubMode Mode = ARM_AM::ia; |
| // VFP and Thumb2 do not support IB or DA modes. |
| bool isNotVFP = isi32Load(Opcode) || isi32Store(Opcode); |
| bool haveIBAndDA = isNotVFP && !isThumb2; |
| if (Offset == 4 && haveIBAndDA) |
| Mode = ARM_AM::ib; |
| else if (Offset == -4 * (int)NumRegs + 4 && haveIBAndDA) |
| Mode = ARM_AM::da; |
| else if (Offset == -4 * (int)NumRegs && isNotVFP) |
| // VLDM/VSTM do not support DB mode without also updating the base reg. |
| Mode = ARM_AM::db; |
| else if (Offset != 0) { |
| // Check if this is a supported opcode before we insert instructions to |
| // calculate a new base register. |
| if (!getLoadStoreMultipleOpcode(Opcode, Mode)) return false; |
| |
| // If starting offset isn't zero, insert a MI to materialize a new base. |
| // But only do so if it is cost effective, i.e. merging more than two |
| // loads / stores. |
| if (NumRegs <= 2) |
| return false; |
| |
| unsigned NewBase; |
| if (isi32Load(Opcode)) |
| // If it is a load, then just use one of the destination register to |
| // use as the new base. |
| NewBase = Regs[NumRegs-1].first; |
| else { |
| // Use the scratch register to use as a new base. |
| NewBase = Scratch; |
| if (NewBase == 0) |
| return false; |
| } |
| int BaseOpc = !isThumb2 ? ARM::ADDri : ARM::t2ADDri; |
| if (Offset < 0) { |
| BaseOpc = !isThumb2 ? ARM::SUBri : ARM::t2SUBri; |
| Offset = - Offset; |
| } |
| int ImmedOffset = isThumb2 |
| ? ARM_AM::getT2SOImmVal(Offset) : ARM_AM::getSOImmVal(Offset); |
| if (ImmedOffset == -1) |
| // FIXME: Try t2ADDri12 or t2SUBri12? |
| return false; // Probably not worth it then. |
| |
| BuildMI(MBB, MBBI, dl, TII->get(BaseOpc), NewBase) |
| .addReg(Base, getKillRegState(BaseKill)).addImm(Offset) |
| .addImm(Pred).addReg(PredReg).addReg(0); |
| Base = NewBase; |
| BaseKill = true; // New base is always killed right its use. |
| } |
| |
| bool isDef = (isi32Load(Opcode) || Opcode == ARM::VLDRS || |
| Opcode == ARM::VLDRD); |
| Opcode = getLoadStoreMultipleOpcode(Opcode, Mode); |
| if (!Opcode) return false; |
| MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII->get(Opcode)) |
| .addReg(Base, getKillRegState(BaseKill)) |
| .addImm(Pred).addReg(PredReg); |
| for (unsigned i = 0; i != NumRegs; ++i) |
| MIB = MIB.addReg(Regs[i].first, getDefRegState(isDef) |
| | getKillRegState(Regs[i].second)); |
| |
| return true; |
| } |
| |
| // MergeOpsUpdate - call MergeOps and update MemOps and merges accordingly on |
| // success. |
| void ARMLoadStoreOpt::MergeOpsUpdate(MachineBasicBlock &MBB, |
| MemOpQueue &memOps, |
| unsigned memOpsBegin, unsigned memOpsEnd, |
| unsigned insertAfter, int Offset, |
| unsigned Base, bool BaseKill, |
| int Opcode, |
| ARMCC::CondCodes Pred, unsigned PredReg, |
| unsigned Scratch, |
| DebugLoc dl, |
| SmallVector<MachineBasicBlock::iterator, 4> &Merges) { |
| // First calculate which of the registers should be killed by the merged |
| // instruction. |
| const unsigned insertPos = memOps[insertAfter].Position; |
| SmallSet<unsigned, 4> KilledRegs; |
| DenseMap<unsigned, unsigned> Killer; |
| for (unsigned i = 0, e = memOps.size(); i != e; ++i) { |
| if (i == memOpsBegin) { |
| i = memOpsEnd; |
| if (i == e) |
| break; |
| } |
| if (memOps[i].Position < insertPos && memOps[i].isKill) { |
| unsigned Reg = memOps[i].Reg; |
| KilledRegs.insert(Reg); |
| Killer[Reg] = i; |
| } |
| } |
| |
| SmallVector<std::pair<unsigned, bool>, 8> Regs; |
| for (unsigned i = memOpsBegin; i < memOpsEnd; ++i) { |
| unsigned Reg = memOps[i].Reg; |
| // If we are inserting the merged operation after an operation that |
| // uses the same register, make sure to transfer any kill flag. |
| bool isKill = memOps[i].isKill || KilledRegs.count(Reg); |
| Regs.push_back(std::make_pair(Reg, isKill)); |
| } |
| |
| // Try to do the merge. |
| MachineBasicBlock::iterator Loc = memOps[insertAfter].MBBI; |
| ++Loc; |
| if (!MergeOps(MBB, Loc, Offset, Base, BaseKill, Opcode, |
| Pred, PredReg, Scratch, dl, Regs)) |
| return; |
| |
| // Merge succeeded, update records. |
| Merges.push_back(prior(Loc)); |
| for (unsigned i = memOpsBegin; i < memOpsEnd; ++i) { |
| // Remove kill flags from any memops that come before insertPos. |
| if (Regs[i-memOpsBegin].second) { |
| unsigned Reg = Regs[i-memOpsBegin].first; |
| if (KilledRegs.count(Reg)) { |
| unsigned j = Killer[Reg]; |
| int Idx = memOps[j].MBBI->findRegisterUseOperandIdx(Reg, true); |
| assert(Idx >= 0 && "Cannot find killing operand"); |
| memOps[j].MBBI->getOperand(Idx).setIsKill(false); |
| memOps[j].isKill = false; |
| } |
| memOps[i].isKill = true; |
| } |
| MBB.erase(memOps[i].MBBI); |
| // Update this memop to refer to the merged instruction. |
| // We may need to move kill flags again. |
| memOps[i].Merged = true; |
| memOps[i].MBBI = Merges.back(); |
| memOps[i].Position = insertPos; |
| } |
| } |
| |
| /// MergeLDR_STR - Merge a number of load / store instructions into one or more |
| /// load / store multiple instructions. |
| void |
| ARMLoadStoreOpt::MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex, |
| unsigned Base, int Opcode, unsigned Size, |
| ARMCC::CondCodes Pred, unsigned PredReg, |
| unsigned Scratch, MemOpQueue &MemOps, |
| SmallVector<MachineBasicBlock::iterator, 4> &Merges) { |
| bool isNotVFP = isi32Load(Opcode) || isi32Store(Opcode); |
| int Offset = MemOps[SIndex].Offset; |
| int SOffset = Offset; |
| unsigned insertAfter = SIndex; |
| MachineBasicBlock::iterator Loc = MemOps[SIndex].MBBI; |
| DebugLoc dl = Loc->getDebugLoc(); |
| const MachineOperand &PMO = Loc->getOperand(0); |
| unsigned PReg = PMO.getReg(); |
| unsigned PRegNum = PMO.isUndef() ? UINT_MAX |
| : getARMRegisterNumbering(PReg); |
| unsigned Count = 1; |
| unsigned Limit = ~0U; |
| |
| // vldm / vstm limit are 32 for S variants, 16 for D variants. |
| |
| switch (Opcode) { |
| default: break; |
| case ARM::VSTRS: |
| Limit = 32; |
| break; |
| case ARM::VSTRD: |
| Limit = 16; |
| break; |
| case ARM::VLDRD: |
| Limit = 16; |
| break; |
| case ARM::VLDRS: |
| Limit = 32; |
| break; |
| } |
| |
| for (unsigned i = SIndex+1, e = MemOps.size(); i != e; ++i) { |
| int NewOffset = MemOps[i].Offset; |
| const MachineOperand &MO = MemOps[i].MBBI->getOperand(0); |
| unsigned Reg = MO.getReg(); |
| unsigned RegNum = MO.isUndef() ? UINT_MAX |
| : getARMRegisterNumbering(Reg); |
| // Register numbers must be in ascending order. For VFP / NEON load and |
| // store multiples, the registers must also be consecutive and within the |
| // limit on the number of registers per instruction. |
| if (Reg != ARM::SP && |
| NewOffset == Offset + (int)Size && |
| ((isNotVFP && RegNum > PRegNum) || |
| ((Count < Limit) && RegNum == PRegNum+1))) { |
| Offset += Size; |
| PRegNum = RegNum; |
| ++Count; |
| } else { |
| // Can't merge this in. Try merge the earlier ones first. |
| MergeOpsUpdate(MBB, MemOps, SIndex, i, insertAfter, SOffset, |
| Base, false, Opcode, Pred, PredReg, Scratch, dl, Merges); |
| MergeLDR_STR(MBB, i, Base, Opcode, Size, Pred, PredReg, Scratch, |
| MemOps, Merges); |
| return; |
| } |
| |
| if (MemOps[i].Position > MemOps[insertAfter].Position) |
| insertAfter = i; |
| } |
| |
| bool BaseKill = Loc->findRegisterUseOperandIdx(Base, true) != -1; |
| MergeOpsUpdate(MBB, MemOps, SIndex, MemOps.size(), insertAfter, SOffset, |
| Base, BaseKill, Opcode, Pred, PredReg, Scratch, dl, Merges); |
| return; |
| } |
| |
| static inline bool isMatchingDecrement(MachineInstr *MI, unsigned Base, |
| unsigned Bytes, unsigned Limit, |
| ARMCC::CondCodes Pred, unsigned PredReg){ |
| unsigned MyPredReg = 0; |
| if (!MI) |
| return false; |
| if (MI->getOpcode() != ARM::t2SUBri && |
| MI->getOpcode() != ARM::tSUBspi && |
| MI->getOpcode() != ARM::SUBri) |
| return false; |
| |
| // Make sure the offset fits in 8 bits. |
| if (Bytes == 0 || (Limit && Bytes >= Limit)) |
| return false; |
| |
| unsigned Scale = (MI->getOpcode() == ARM::tSUBspi) ? 4 : 1; // FIXME |
| return (MI->getOperand(0).getReg() == Base && |
| MI->getOperand(1).getReg() == Base && |
| (MI->getOperand(2).getImm()*Scale) == Bytes && |
| llvm::getInstrPredicate(MI, MyPredReg) == Pred && |
| MyPredReg == PredReg); |
| } |
| |
| static inline bool isMatchingIncrement(MachineInstr *MI, unsigned Base, |
| unsigned Bytes, unsigned Limit, |
| ARMCC::CondCodes Pred, unsigned PredReg){ |
| unsigned MyPredReg = 0; |
| if (!MI) |
| return false; |
| if (MI->getOpcode() != ARM::t2ADDri && |
| MI->getOpcode() != ARM::tADDspi && |
| MI->getOpcode() != ARM::ADDri) |
| return false; |
| |
| if (Bytes == 0 || (Limit && Bytes >= Limit)) |
| // Make sure the offset fits in 8 bits. |
| return false; |
| |
| unsigned Scale = (MI->getOpcode() == ARM::tADDspi) ? 4 : 1; // FIXME |
| return (MI->getOperand(0).getReg() == Base && |
| MI->getOperand(1).getReg() == Base && |
| (MI->getOperand(2).getImm()*Scale) == Bytes && |
| llvm::getInstrPredicate(MI, MyPredReg) == Pred && |
| MyPredReg == PredReg); |
| } |
| |
| static inline unsigned getLSMultipleTransferSize(MachineInstr *MI) { |
| switch (MI->getOpcode()) { |
| default: return 0; |
| case ARM::LDRi12: |
| case ARM::STRi12: |
| case ARM::t2LDRi8: |
| case ARM::t2LDRi12: |
| case ARM::t2STRi8: |
| case ARM::t2STRi12: |
| case ARM::VLDRS: |
| case ARM::VSTRS: |
| return 4; |
| case ARM::VLDRD: |
| case ARM::VSTRD: |
| return 8; |
| case ARM::LDMIA: |
| case ARM::LDMDA: |
| case ARM::LDMDB: |
| case ARM::LDMIB: |
| case ARM::STMIA: |
| case ARM::STMDA: |
| case ARM::STMDB: |
| case ARM::STMIB: |
| case ARM::t2LDMIA: |
| case ARM::t2LDMDB: |
| case ARM::t2STMIA: |
| case ARM::t2STMDB: |
| case ARM::VLDMSIA: |
| case ARM::VSTMSIA: |
| return (MI->getNumOperands() - MI->getDesc().getNumOperands() + 1) * 4; |
| case ARM::VLDMDIA: |
| case ARM::VSTMDIA: |
| return (MI->getNumOperands() - MI->getDesc().getNumOperands() + 1) * 8; |
| } |
| } |
| |
| static unsigned getUpdatingLSMultipleOpcode(unsigned Opc, |
| ARM_AM::AMSubMode Mode) { |
| switch (Opc) { |
| default: llvm_unreachable("Unhandled opcode!"); |
| case ARM::LDMIA: |
| case ARM::LDMDA: |
| case ARM::LDMDB: |
| case ARM::LDMIB: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::LDMIA_UPD; |
| case ARM_AM::ib: return ARM::LDMIB_UPD; |
| case ARM_AM::da: return ARM::LDMDA_UPD; |
| case ARM_AM::db: return ARM::LDMDB_UPD; |
| } |
| break; |
| case ARM::STMIA: |
| case ARM::STMDA: |
| case ARM::STMDB: |
| case ARM::STMIB: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::STMIA_UPD; |
| case ARM_AM::ib: return ARM::STMIB_UPD; |
| case ARM_AM::da: return ARM::STMDA_UPD; |
| case ARM_AM::db: return ARM::STMDB_UPD; |
| } |
| break; |
| case ARM::t2LDMIA: |
| case ARM::t2LDMDB: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::t2LDMIA_UPD; |
| case ARM_AM::db: return ARM::t2LDMDB_UPD; |
| } |
| break; |
| case ARM::t2STMIA: |
| case ARM::t2STMDB: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::t2STMIA_UPD; |
| case ARM_AM::db: return ARM::t2STMDB_UPD; |
| } |
| break; |
| case ARM::VLDMSIA: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VLDMSIA_UPD; |
| case ARM_AM::db: return ARM::VLDMSDB_UPD; |
| } |
| break; |
| case ARM::VLDMDIA: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VLDMDIA_UPD; |
| case ARM_AM::db: return ARM::VLDMDDB_UPD; |
| } |
| break; |
| case ARM::VSTMSIA: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VSTMSIA_UPD; |
| case ARM_AM::db: return ARM::VSTMSDB_UPD; |
| } |
| break; |
| case ARM::VSTMDIA: |
| switch (Mode) { |
| default: llvm_unreachable("Unhandled submode!"); |
| case ARM_AM::ia: return ARM::VSTMDIA_UPD; |
| case ARM_AM::db: return ARM::VSTMDDB_UPD; |
| } |
| break; |
| } |
| |
| return 0; |
| } |
| |
| /// MergeBaseUpdateLSMultiple - Fold proceeding/trailing inc/dec of base |
| /// register into the LDM/STM/VLDM{D|S}/VSTM{D|S} op when possible: |
| /// |
| /// stmia rn, <ra, rb, rc> |
| /// rn := rn + 4 * 3; |
| /// => |
| /// stmia rn!, <ra, rb, rc> |
| /// |
| /// rn := rn - 4 * 3; |
| /// ldmia rn, <ra, rb, rc> |
| /// => |
| /// ldmdb rn!, <ra, rb, rc> |
| bool ARMLoadStoreOpt::MergeBaseUpdateLSMultiple(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| bool &Advance, |
| MachineBasicBlock::iterator &I) { |
| MachineInstr *MI = MBBI; |
| unsigned Base = MI->getOperand(0).getReg(); |
| bool BaseKill = MI->getOperand(0).isKill(); |
| unsigned Bytes = getLSMultipleTransferSize(MI); |
| unsigned PredReg = 0; |
| ARMCC::CondCodes Pred = llvm::getInstrPredicate(MI, PredReg); |
| int Opcode = MI->getOpcode(); |
| DebugLoc dl = MI->getDebugLoc(); |
| |
| // Can't use an updating ld/st if the base register is also a dest |
| // register. e.g. ldmdb r0!, {r0, r1, r2}. The behavior is undefined. |
| for (unsigned i = 2, e = MI->getNumOperands(); i != e; ++i) |
| if (MI->getOperand(i).getReg() == Base) |
| return false; |
| |
| bool DoMerge = false; |
| ARM_AM::AMSubMode Mode = ARM_AM::getLoadStoreMultipleSubMode(Opcode); |
| |
| // Try merging with the previous instruction. |
| MachineBasicBlock::iterator BeginMBBI = MBB.begin(); |
| if (MBBI != BeginMBBI) { |
| MachineBasicBlock::iterator PrevMBBI = prior(MBBI); |
| while (PrevMBBI != BeginMBBI && PrevMBBI->isDebugValue()) |
| --PrevMBBI; |
| if (Mode == ARM_AM::ia && |
| isMatchingDecrement(PrevMBBI, Base, Bytes, 0, Pred, PredReg)) { |
| Mode = ARM_AM::db; |
| DoMerge = true; |
| } else if (Mode == ARM_AM::ib && |
| isMatchingDecrement(PrevMBBI, Base, Bytes, 0, Pred, PredReg)) { |
| Mode = ARM_AM::da; |
| DoMerge = true; |
| } |
| if (DoMerge) |
| MBB.erase(PrevMBBI); |
| } |
| |
| // Try merging with the next instruction. |
| MachineBasicBlock::iterator EndMBBI = MBB.end(); |
| if (!DoMerge && MBBI != EndMBBI) { |
| MachineBasicBlock::iterator NextMBBI = llvm::next(MBBI); |
| while (NextMBBI != EndMBBI && NextMBBI->isDebugValue()) |
| ++NextMBBI; |
| if ((Mode == ARM_AM::ia || Mode == ARM_AM::ib) && |
| isMatchingIncrement(NextMBBI, Base, Bytes, 0, Pred, PredReg)) { |
| DoMerge = true; |
| } else if ((Mode == ARM_AM::da || Mode == ARM_AM::db) && |
| isMatchingDecrement(NextMBBI, Base, Bytes, 0, Pred, PredReg)) { |
| DoMerge = true; |
| } |
| if (DoMerge) { |
| if (NextMBBI == I) { |
| Advance = true; |
| ++I; |
| } |
| MBB.erase(NextMBBI); |
| } |
| } |
| |
| if (!DoMerge) |
| return false; |
| |
| unsigned NewOpc = getUpdatingLSMultipleOpcode(Opcode, Mode); |
| MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII->get(NewOpc)) |
| .addReg(Base, getDefRegState(true)) // WB base register |
| .addReg(Base, getKillRegState(BaseKill)) |
| .addImm(Pred).addReg(PredReg); |
| |
| // Transfer the rest of operands. |
| for (unsigned OpNum = 3, e = MI->getNumOperands(); OpNum != e; ++OpNum) |
| MIB.addOperand(MI->getOperand(OpNum)); |
| |
| // Transfer memoperands. |
| MIB->setMemRefs(MI->memoperands_begin(), MI->memoperands_end()); |
| |
| MBB.erase(MBBI); |
| return true; |
| } |
| |
| static unsigned getPreIndexedLoadStoreOpcode(unsigned Opc, |
| ARM_AM::AddrOpc Mode) { |
| switch (Opc) { |
| case ARM::LDRi12: |
| return ARM::LDR_PRE_IMM; |
| case ARM::STRi12: |
| return ARM::STR_PRE_IMM; |
| case ARM::VLDRS: |
| return Mode == ARM_AM::add ? ARM::VLDMSIA_UPD : ARM::VLDMSDB_UPD; |
| case ARM::VLDRD: |
| return Mode == ARM_AM::add ? ARM::VLDMDIA_UPD : ARM::VLDMDDB_UPD; |
| case ARM::VSTRS: |
| return Mode == ARM_AM::add ? ARM::VSTMSIA_UPD : ARM::VSTMSDB_UPD; |
| case ARM::VSTRD: |
| return Mode == ARM_AM::add ? ARM::VSTMDIA_UPD : ARM::VSTMDDB_UPD; |
| case ARM::t2LDRi8: |
| case ARM::t2LDRi12: |
| return ARM::t2LDR_PRE; |
| case ARM::t2STRi8: |
| case ARM::t2STRi12: |
| return ARM::t2STR_PRE; |
| default: llvm_unreachable("Unhandled opcode!"); |
| } |
| return 0; |
| } |
| |
| static unsigned getPostIndexedLoadStoreOpcode(unsigned Opc, |
| ARM_AM::AddrOpc Mode) { |
| switch (Opc) { |
| case ARM::LDRi12: |
| return ARM::LDR_POST_IMM; |
| case ARM::STRi12: |
| return ARM::STR_POST_IMM; |
| case ARM::VLDRS: |
| return Mode == ARM_AM::add ? ARM::VLDMSIA_UPD : ARM::VLDMSDB_UPD; |
| case ARM::VLDRD: |
| return Mode == ARM_AM::add ? ARM::VLDMDIA_UPD : ARM::VLDMDDB_UPD; |
| case ARM::VSTRS: |
| return Mode == ARM_AM::add ? ARM::VSTMSIA_UPD : ARM::VSTMSDB_UPD; |
| case ARM::VSTRD: |
| return Mode == ARM_AM::add ? ARM::VSTMDIA_UPD : ARM::VSTMDDB_UPD; |
| case ARM::t2LDRi8: |
| case ARM::t2LDRi12: |
| return ARM::t2LDR_POST; |
| case ARM::t2STRi8: |
| case ARM::t2STRi12: |
| return ARM::t2STR_POST; |
| default: llvm_unreachable("Unhandled opcode!"); |
| } |
| return 0; |
| } |
| |
| /// MergeBaseUpdateLoadStore - Fold proceeding/trailing inc/dec of base |
| /// register into the LDR/STR/FLD{D|S}/FST{D|S} op when possible: |
| bool ARMLoadStoreOpt::MergeBaseUpdateLoadStore(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI, |
| const TargetInstrInfo *TII, |
| bool &Advance, |
| MachineBasicBlock::iterator &I) { |
| MachineInstr *MI = MBBI; |
| unsigned Base = MI->getOperand(1).getReg(); |
| bool BaseKill = MI->getOperand(1).isKill(); |
| unsigned Bytes = getLSMultipleTransferSize(MI); |
| int Opcode = MI->getOpcode(); |
| DebugLoc dl = MI->getDebugLoc(); |
| bool isAM5 = (Opcode == ARM::VLDRD || Opcode == ARM::VLDRS || |
| Opcode == ARM::VSTRD || Opcode == ARM::VSTRS); |
| bool isAM2 = (Opcode == ARM::LDRi12 || Opcode == ARM::STRi12); |
| if (isi32Load(Opcode) || isi32Store(Opcode)) |
| if (MI->getOperand(2).getImm() != 0) |
| return false; |
| if (isAM5 && ARM_AM::getAM5Offset(MI->getOperand(2).getImm()) != 0) |
| return false; |
| |
| bool isLd = isi32Load(Opcode) || Opcode == ARM::VLDRS || Opcode == ARM::VLDRD; |
| // Can't do the merge if the destination register is the same as the would-be |
| // writeback register. |
| if (isLd && MI->getOperand(0).getReg() == Base) |
| return false; |
| |
| unsigned PredReg = 0; |
| ARMCC::CondCodes Pred = llvm::getInstrPredicate(MI, PredReg); |
| bool DoMerge = false; |
| ARM_AM::AddrOpc AddSub = ARM_AM::add; |
| unsigned NewOpc = 0; |
| // AM2 - 12 bits, thumb2 - 8 bits. |
| unsigned Limit = isAM5 ? 0 : (isAM2 ? 0x1000 : 0x100); |
| |
| // Try merging with the previous instruction. |
| MachineBasicBlock::iterator BeginMBBI = MBB.begin(); |
| if (MBBI != BeginMBBI) { |
| MachineBasicBlock::iterator PrevMBBI = prior(MBBI); |
| while (PrevMBBI != BeginMBBI && PrevMBBI->isDebugValue()) |
| --PrevMBBI; |
| if (isMatchingDecrement(PrevMBBI, Base, Bytes, Limit, Pred, PredReg)) { |
| DoMerge = true; |
| AddSub = ARM_AM::sub; |
| } else if (!isAM5 && |
| isMatchingIncrement(PrevMBBI, Base, Bytes, Limit,Pred,PredReg)) { |
| DoMerge = true; |
| } |
| if (DoMerge) { |
| NewOpc = getPreIndexedLoadStoreOpcode(Opcode, AddSub); |
| MBB.erase(PrevMBBI); |
| } |
| } |
| |
| // Try merging with the next instruction. |
| MachineBasicBlock::iterator EndMBBI = MBB.end(); |
| if (!DoMerge && MBBI != EndMBBI) { |
| MachineBasicBlock::iterator NextMBBI = llvm::next(MBBI); |
| while (NextMBBI != EndMBBI && NextMBBI->isDebugValue()) |
| ++NextMBBI; |
| if (!isAM5 && |
| isMatchingDecrement(NextMBBI, Base, Bytes, Limit, Pred, PredReg)) { |
| DoMerge = true; |
| AddSub = ARM_AM::sub; |
| } else if (isMatchingIncrement(NextMBBI, Base, Bytes, Limit,Pred,PredReg)) { |
| DoMerge = true; |
| } |
| if (DoMerge) { |
| NewOpc = getPostIndexedLoadStoreOpcode(Opcode, AddSub); |
| if (NextMBBI == I) { |
| Advance = true; |
| ++I; |
| } |
| MBB.erase(NextMBBI); |
| } |
| } |
| |
| if (!DoMerge) |
| return false; |
| |
| if (isAM5) { |
| // VLDM[SD}_UPD, VSTM[SD]_UPD |
| // (There are no base-updating versions of VLDR/VSTR instructions, but the |
| // updating load/store-multiple instructions can be used with only one |
| // register.) |
| MachineOperand &MO = MI->getOperand(0); |
| BuildMI(MBB, MBBI, dl, TII->get(NewOpc)) |
| .addReg(Base, getDefRegState(true)) // WB base register |
| .addReg(Base, getKillRegState(isLd ? BaseKill : false)) |
| .addImm(Pred).addReg(PredReg) |
| .addReg(MO.getReg(), (isLd ? getDefRegState(true) : |
| getKillRegState(MO.isKill()))); |
| } else if (isLd) { |
| if (isAM2) { |
| // LDR_PRE, LDR_POST |
| if (NewOpc == ARM::LDR_PRE_IMM || NewOpc == ARM::LDRB_PRE_IMM) { |
| int Offset = AddSub == ARM_AM::sub ? -Bytes : Bytes; |
| BuildMI(MBB, MBBI, dl, TII->get(NewOpc), MI->getOperand(0).getReg()) |
| .addReg(Base, RegState::Define) |
| .addReg(Base).addImm(Offset).addImm(Pred).addReg(PredReg); |
| } else { |
| int Offset = ARM_AM::getAM2Opc(AddSub, Bytes, ARM_AM::no_shift); |
| BuildMI(MBB, MBBI, dl, TII->get(NewOpc), MI->getOperand(0).getReg()) |
| .addReg(Base, RegState::Define) |
| .addReg(Base).addReg(0).addImm(Offset).addImm(Pred).addReg(PredReg); |
| } |
| } else { |
| int Offset = AddSub == ARM_AM::sub ? -Bytes : Bytes; |
| // t2LDR_PRE, t2LDR_POST |
| BuildMI(MBB, MBBI, dl, TII->get(NewOpc), MI->getOperand(0).getReg()) |
| .addReg(Base, RegState::Define) |
| .addReg(Base).addImm(Offset).addImm(Pred).addReg(PredReg); |
| } |
| } else { |
| MachineOperand &MO = MI->getOperand(0); |
| // FIXME: post-indexed stores use am2offset_imm, which still encodes |
| // the vestigal zero-reg offset register. When that's fixed, this clause |
| // can be removed entirely. |
| if (isAM2 && NewOpc == ARM::STR_POST_IMM) { |
| int Offset = ARM_AM::getAM2Opc(AddSub, Bytes, ARM_AM::no_shift); |
| // STR_PRE, STR_POST |
| BuildMI(MBB, MBBI, dl, TII->get(NewOpc), Base) |
| .addReg(MO.getReg(), getKillRegState(MO.isKill())) |
| .addReg(Base).addReg(0).addImm(Offset).addImm(Pred).addReg(PredReg); |
| } else { |
| int Offset = AddSub == ARM_AM::sub ? -Bytes : Bytes; |
| // t2STR_PRE, t2STR_POST |
| BuildMI(MBB, MBBI, dl, TII->get(NewOpc), Base) |
| .addReg(MO.getReg(), getKillRegState(MO.isKill())) |
| .addReg(Base).addImm(Offset).addImm(Pred).addReg(PredReg); |
| } |
| } |
| MBB.erase(MBBI); |
| |
| return true; |
| } |
| |
| /// isMemoryOp - Returns true if instruction is a memory operation that this |
| /// pass is capable of operating on. |
| static bool isMemoryOp(const MachineInstr *MI) { |
| // When no memory operands are present, conservatively assume unaligned, |
| // volatile, unfoldable. |
| if (!MI->hasOneMemOperand()) |
| return false; |
| |
| const MachineMemOperand *MMO = *MI->memoperands_begin(); |
| |
| // Don't touch volatile memory accesses - we may be changing their order. |
| if (MMO->isVolatile()) |
| return false; |
| |
| // Unaligned ldr/str is emulated by some kernels, but unaligned ldm/stm is |
| // not. |
| if (MMO->getAlignment() < 4) |
| return false; |
| |
| // str <undef> could probably be eliminated entirely, but for now we just want |
| // to avoid making a mess of it. |
| // FIXME: Use str <undef> as a wildcard to enable better stm folding. |
| if (MI->getNumOperands() > 0 && MI->getOperand(0).isReg() && |
| MI->getOperand(0).isUndef()) |
| return false; |
| |
| // Likewise don't mess with references to undefined addresses. |
| if (MI->getNumOperands() > 1 && MI->getOperand(1).isReg() && |
| MI->getOperand(1).isUndef()) |
| return false; |
| |
| int Opcode = MI->getOpcode(); |
| switch (Opcode) { |
| default: break; |
| case ARM::VLDRS: |
| case ARM::VSTRS: |
| return MI->getOperand(1).isReg(); |
| case ARM::VLDRD: |
| case ARM::VSTRD: |
| return MI->getOperand(1).isReg(); |
| case ARM::LDRi12: |
| case ARM::STRi12: |
| case ARM::t2LDRi8: |
| case ARM::t2LDRi12: |
| case ARM::t2STRi8: |
| case ARM::t2STRi12: |
| return MI->getOperand(1).isReg(); |
| } |
| return false; |
| } |
| |
| /// AdvanceRS - Advance register scavenger to just before the earliest memory |
| /// op that is being merged. |
| void ARMLoadStoreOpt::AdvanceRS(MachineBasicBlock &MBB, MemOpQueue &MemOps) { |
| MachineBasicBlock::iterator Loc = MemOps[0].MBBI; |
| unsigned Position = MemOps[0].Position; |
| for (unsigned i = 1, e = MemOps.size(); i != e; ++i) { |
| if (MemOps[i].Position < Position) { |
| Position = MemOps[i].Position; |
| Loc = MemOps[i].MBBI; |
| } |
| } |
| |
| if (Loc != MBB.begin()) |
| RS->forward(prior(Loc)); |
| } |
| |
| static int getMemoryOpOffset(const MachineInstr *MI) { |
| int Opcode = MI->getOpcode(); |
| bool isAM3 = Opcode == ARM::LDRD || Opcode == ARM::STRD; |
| unsigned NumOperands = MI->getDesc().getNumOperands(); |
| unsigned OffField = MI->getOperand(NumOperands-3).getImm(); |
| |
| if (Opcode == ARM::t2LDRi12 || Opcode == ARM::t2LDRi8 || |
| Opcode == ARM::t2STRi12 || Opcode == ARM::t2STRi8 || |
| Opcode == ARM::t2LDRDi8 || Opcode == ARM::t2STRDi8 || |
| Opcode == ARM::LDRi12 || Opcode == ARM::STRi12) |
| return OffField; |
| |
| int Offset = isAM3 ? ARM_AM::getAM3Offset(OffField) |
| : ARM_AM::getAM5Offset(OffField) * 4; |
| if (isAM3) { |
| if (ARM_AM::getAM3Op(OffField) == ARM_AM::sub) |
| Offset = -Offset; |
| } else { |
| if (ARM_AM::getAM5Op(OffField) == ARM_AM::sub) |
| Offset = -Offset; |
| } |
| return Offset; |
| } |
| |
| static void InsertLDR_STR(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator &MBBI, |
| int Offset, bool isDef, |
| DebugLoc dl, unsigned NewOpc, |
| unsigned Reg, bool RegDeadKill, bool RegUndef, |
| unsigned BaseReg, bool BaseKill, bool BaseUndef, |
| bool OffKill, bool OffUndef, |
| ARMCC::CondCodes Pred, unsigned PredReg, |
| const TargetInstrInfo *TII, bool isT2) { |
| if (isDef) { |
| MachineInstrBuilder MIB = BuildMI(MBB, MBBI, MBBI->getDebugLoc(), |
| TII->get(NewOpc)) |
| .addReg(Reg, getDefRegState(true) | getDeadRegState(RegDeadKill)) |
| .addReg(BaseReg, getKillRegState(BaseKill)|getUndefRegState(BaseUndef)); |
| MIB.addImm(Offset).addImm(Pred).addReg(PredReg); |
| } else { |
| MachineInstrBuilder MIB = BuildMI(MBB, MBBI, MBBI->getDebugLoc(), |
| TII->get(NewOpc)) |
| .addReg(Reg, getKillRegState(RegDeadKill) | getUndefRegState(RegUndef)) |
| .addReg(BaseReg, getKillRegState(BaseKill)|getUndefRegState(BaseUndef)); |
| MIB.addImm(Offset).addImm(Pred).addReg(PredReg); |
| } |
| } |
| |
| bool ARMLoadStoreOpt::FixInvalidRegPairOp(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator &MBBI) { |
| MachineInstr *MI = &*MBBI; |
| unsigned Opcode = MI->getOpcode(); |
| if (Opcode == ARM::LDRD || Opcode == ARM::STRD || |
| Opcode == ARM::t2LDRDi8 || Opcode == ARM::t2STRDi8) { |
| const MachineOperand &BaseOp = MI->getOperand(2); |
| unsigned BaseReg = BaseOp.getReg(); |
| unsigned EvenReg = MI->getOperand(0).getReg(); |
| unsigned OddReg = MI->getOperand(1).getReg(); |
| unsigned EvenRegNum = TRI->getDwarfRegNum(EvenReg, false); |
| unsigned OddRegNum = TRI->getDwarfRegNum(OddReg, false); |
| // ARM errata 602117: LDRD with base in list may result in incorrect base |
| // register when interrupted or faulted. |
| bool Errata602117 = EvenReg == BaseReg && STI->isCortexM3(); |
| if (!Errata602117 && |
| ((EvenRegNum & 1) == 0 && (EvenRegNum + 1) == OddRegNum)) |
| return false; |
| |
| MachineBasicBlock::iterator NewBBI = MBBI; |
| bool isT2 = Opcode == ARM::t2LDRDi8 || Opcode == ARM::t2STRDi8; |
| bool isLd = Opcode == ARM::LDRD || Opcode == ARM::t2LDRDi8; |
| bool EvenDeadKill = isLd ? |
| MI->getOperand(0).isDead() : MI->getOperand(0).isKill(); |
| bool EvenUndef = MI->getOperand(0).isUndef(); |
| bool OddDeadKill = isLd ? |
| MI->getOperand(1).isDead() : MI->getOperand(1).isKill(); |
| bool OddUndef = MI->getOperand(1).isUndef(); |
| bool BaseKill = BaseOp.isKill(); |
| bool BaseUndef = BaseOp.isUndef(); |
| bool OffKill = isT2 ? false : MI->getOperand(3).isKill(); |
| bool OffUndef = isT2 ? false : MI->getOperand(3).isUndef(); |
| int OffImm = getMemoryOpOffset(MI); |
| unsigned PredReg = 0; |
| ARMCC::CondCodes Pred = llvm::getInstrPredicate(MI, PredReg); |
| |
| if (OddRegNum > EvenRegNum && OffImm == 0) { |
| // Ascending register numbers and no offset. It's safe to change it to a |
| // ldm or stm. |
| unsigned NewOpc = (isLd) |
| ? (isT2 ? ARM::t2LDMIA : ARM::LDMIA) |
| : (isT2 ? ARM::t2STMIA : ARM::STMIA); |
| if (isLd) { |
| BuildMI(MBB, MBBI, MBBI->getDebugLoc(), TII->get(NewOpc)) |
| .addReg(BaseReg, getKillRegState(BaseKill)) |
| .addImm(Pred).addReg(PredReg) |
| .addReg(EvenReg, getDefRegState(isLd) | getDeadRegState(EvenDeadKill)) |
| .addReg(OddReg, getDefRegState(isLd) | getDeadRegState(OddDeadKill)); |
| ++NumLDRD2LDM; |
| } else { |
| BuildMI(MBB, MBBI, MBBI->getDebugLoc(), TII->get(NewOpc)) |
| .addReg(BaseReg, getKillRegState(BaseKill)) |
| .addImm(Pred).addReg(PredReg) |
| .addReg(EvenReg, |
| getKillRegState(EvenDeadKill) | getUndefRegState(EvenUndef)) |
| .addReg(OddReg, |
| getKillRegState(OddDeadKill) | getUndefRegState(OddUndef)); |
| ++NumSTRD2STM; |
| } |
| NewBBI = llvm::prior(MBBI); |
| } else { |
| // Split into two instructions. |
| unsigned NewOpc = (isLd) |
| ? (isT2 ? (OffImm < 0 ? ARM::t2LDRi8 : ARM::t2LDRi12) : ARM::LDRi12) |
| : (isT2 ? (OffImm < 0 ? ARM::t2STRi8 : ARM::t2STRi12) : ARM::STRi12); |
| DebugLoc dl = MBBI->getDebugLoc(); |
| // If this is a load and base register is killed, it may have been |
| // re-defed by the load, make sure the first load does not clobber it. |
| if (isLd && |
| (BaseKill || OffKill) && |
| (TRI->regsOverlap(EvenReg, BaseReg))) { |
| assert(!TRI->regsOverlap(OddReg, BaseReg)); |
| InsertLDR_STR(MBB, MBBI, OffImm+4, isLd, dl, NewOpc, |
| OddReg, OddDeadKill, false, |
| BaseReg, false, BaseUndef, false, OffUndef, |
| Pred, PredReg, TII, isT2); |
| NewBBI = llvm::prior(MBBI); |
| InsertLDR_STR(MBB, MBBI, OffImm, isLd, dl, NewOpc, |
| EvenReg, EvenDeadKill, false, |
| BaseReg, BaseKill, BaseUndef, OffKill, OffUndef, |
| Pred, PredReg, TII, isT2); |
| } else { |
| if (OddReg == EvenReg && EvenDeadKill) { |
| // If the two source operands are the same, the kill marker is |
| // probably on the first one. e.g. |
| // t2STRDi8 %R5<kill>, %R5, %R9<kill>, 0, 14, %reg0 |
| EvenDeadKill = false; |
| OddDeadKill = true; |
| } |
| InsertLDR_STR(MBB, MBBI, OffImm, isLd, dl, NewOpc, |
| EvenReg, EvenDeadKill, EvenUndef, |
| BaseReg, false, BaseUndef, false, OffUndef, |
| Pred, PredReg, TII, isT2); |
| NewBBI = llvm::prior(MBBI); |
| InsertLDR_STR(MBB, MBBI, OffImm+4, isLd, dl, NewOpc, |
| OddReg, OddDeadKill, OddUndef, |
| BaseReg, BaseKill, BaseUndef, OffKill, OffUndef, |
| Pred, PredReg, TII, isT2); |
| } |
| if (isLd) |
| ++NumLDRD2LDR; |
| else |
| ++NumSTRD2STR; |
| } |
| |
| MBB.erase(MI); |
| MBBI = NewBBI; |
| return true; |
| } |
| return false; |
| } |
| |
| /// LoadStoreMultipleOpti - An optimization pass to turn multiple LDR / STR |
| /// ops of the same base and incrementing offset into LDM / STM ops. |
| bool ARMLoadStoreOpt::LoadStoreMultipleOpti(MachineBasicBlock &MBB) { |
| unsigned NumMerges = 0; |
| unsigned NumMemOps = 0; |
| MemOpQueue MemOps; |
| unsigned CurrBase = 0; |
| int CurrOpc = -1; |
| unsigned CurrSize = 0; |
| ARMCC::CondCodes CurrPred = ARMCC::AL; |
| unsigned CurrPredReg = 0; |
| unsigned Position = 0; |
| SmallVector<MachineBasicBlock::iterator,4> Merges; |
| |
| RS->enterBasicBlock(&MBB); |
| MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end(); |
| while (MBBI != E) { |
| if (FixInvalidRegPairOp(MBB, MBBI)) |
| continue; |
| |
| bool Advance = false; |
| bool TryMerge = false; |
| bool Clobber = false; |
| |
| bool isMemOp = isMemoryOp(MBBI); |
| if (isMemOp) { |
| int Opcode = MBBI->getOpcode(); |
| unsigned Size = getLSMultipleTransferSize(MBBI); |
| const MachineOperand &MO = MBBI->getOperand(0); |
| unsigned Reg = MO.getReg(); |
| bool isKill = MO.isDef() ? false : MO.isKill(); |
| unsigned Base = MBBI->getOperand(1).getReg(); |
| unsigned PredReg = 0; |
| ARMCC::CondCodes Pred = llvm::getInstrPredicate(MBBI, PredReg); |
| int Offset = getMemoryOpOffset(MBBI); |
| // Watch out for: |
| // r4 := ldr [r5] |
| // r5 := ldr [r5, #4] |
| // r6 := ldr [r5, #8] |
| // |
| // The second ldr has effectively broken the chain even though it |
| // looks like the later ldr(s) use the same base register. Try to |
| // merge the ldr's so far, including this one. But don't try to |
| // combine the following ldr(s). |
| Clobber = (isi32Load(Opcode) && Base == MBBI->getOperand(0).getReg()); |
| if (CurrBase == 0 && !Clobber) { |
| // Start of a new chain. |
| CurrBase = Base; |
| CurrOpc = Opcode; |
| CurrSize = Size; |
| CurrPred = Pred; |
| CurrPredReg = PredReg; |
| MemOps.push_back(MemOpQueueEntry(Offset, Reg, isKill, Position, MBBI)); |
| ++NumMemOps; |
| Advance = true; |
| } else { |
| if (Clobber) { |
| TryMerge = true; |
| Advance = true; |
| } |
| |
| if (CurrOpc == Opcode && CurrBase == Base && CurrPred == Pred) { |
| // No need to match PredReg. |
| // Continue adding to the queue. |
| if (Offset > MemOps.back().Offset) { |
| MemOps.push_back(MemOpQueueEntry(Offset, Reg, isKill, |
| Position, MBBI)); |
| ++NumMemOps; |
| Advance = true; |
| } else { |
| for (MemOpQueueIter I = MemOps.begin(), E = MemOps.end(); |
| I != E; ++I) { |
| if (Offset < I->Offset) { |
| MemOps.insert(I, MemOpQueueEntry(Offset, Reg, isKill, |
| Position, MBBI)); |
| ++NumMemOps; |
| Advance = true; |
| break; |
| } else if (Offset == I->Offset) { |
| // Collision! This can't be merged! |
| break; |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| if (MBBI->isDebugValue()) { |
| ++MBBI; |
| if (MBBI == E) |
| // Reach the end of the block, try merging the memory instructions. |
| TryMerge = true; |
| } else if (Advance) { |
| ++Position; |
| ++MBBI; |
| if (MBBI == E) |
| // Reach the end of the block, try merging the memory instructions. |
| TryMerge = true; |
| } else |
| TryMerge = true; |
| |
| if (TryMerge) { |
| if (NumMemOps > 1) { |
| // Try to find a free register to use as a new base in case it's needed. |
| // First advance to the instruction just before the start of the chain. |
| AdvanceRS(MBB, MemOps); |
| // Find a scratch register. |
| unsigned Scratch = RS->FindUnusedReg(ARM::GPRRegisterClass); |
| // Process the load / store instructions. |
| RS->forward(prior(MBBI)); |
| |
| // Merge ops. |
| Merges.clear(); |
| MergeLDR_STR(MBB, 0, CurrBase, CurrOpc, CurrSize, |
| CurrPred, CurrPredReg, Scratch, MemOps, Merges); |
| |
| // Try folding preceding/trailing base inc/dec into the generated |
| // LDM/STM ops. |
| for (unsigned i = 0, e = Merges.size(); i < e; ++i) |
| if (MergeBaseUpdateLSMultiple(MBB, Merges[i], Advance, MBBI)) |
| ++NumMerges; |
| NumMerges += Merges.size(); |
| |
| // Try folding preceding/trailing base inc/dec into those load/store |
| // that were not merged to form LDM/STM ops. |
| for (unsigned i = 0; i != NumMemOps; ++i) |
| if (!MemOps[i].Merged) |
| if (MergeBaseUpdateLoadStore(MBB, MemOps[i].MBBI, TII,Advance,MBBI)) |
| ++NumMerges; |
| |
| // RS may be pointing to an instruction that's deleted. |
| RS->skipTo(prior(MBBI)); |
| } else if (NumMemOps == 1) { |
| // Try folding preceding/trailing base inc/dec into the single |
| // load/store. |
| if (MergeBaseUpdateLoadStore(MBB, MemOps[0].MBBI, TII, Advance, MBBI)) { |
| ++NumMerges; |
| RS->forward(prior(MBBI)); |
| } |
| } |
| |
| CurrBase = 0; |
| CurrOpc = -1; |
| CurrSize = 0; |
| CurrPred = ARMCC::AL; |
| CurrPredReg = 0; |
| if (NumMemOps) { |
| MemOps.clear(); |
| NumMemOps = 0; |
| } |
| |
| // If iterator hasn't been advanced and this is not a memory op, skip it. |
| // It can't start a new chain anyway. |
| if (!Advance && !isMemOp && MBBI != E) { |
| ++Position; |
| ++MBBI; |
| } |
| } |
| } |
| return NumMerges > 0; |
| } |
| |
| /// MergeReturnIntoLDM - If this is a exit BB, try merging the return ops |
| /// ("bx lr" and "mov pc, lr") into the preceding stack restore so it |
| /// directly restore the value of LR into pc. |
| /// ldmfd sp!, {..., lr} |
| /// bx lr |
| /// or |
| /// ldmfd sp!, {..., lr} |
| /// mov pc, lr |
| /// => |
| /// ldmfd sp!, {..., pc} |
| bool ARMLoadStoreOpt::MergeReturnIntoLDM(MachineBasicBlock &MBB) { |
| if (MBB.empty()) return false; |
| |
| MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); |
| if (MBBI != MBB.begin() && |
| (MBBI->getOpcode() == ARM::BX_RET || |
| MBBI->getOpcode() == ARM::tBX_RET || |
| MBBI->getOpcode() == ARM::MOVPCLR)) { |
| MachineInstr *PrevMI = prior(MBBI); |
| unsigned Opcode = PrevMI->getOpcode(); |
| if (Opcode == ARM::LDMIA_UPD || Opcode == ARM::LDMDA_UPD || |
| Opcode == ARM::LDMDB_UPD || Opcode == ARM::LDMIB_UPD || |
| Opcode == ARM::t2LDMIA_UPD || Opcode == ARM::t2LDMDB_UPD) { |
| MachineOperand &MO = PrevMI->getOperand(PrevMI->getNumOperands()-1); |
| if (MO.getReg() != ARM::LR) |
| return false; |
| unsigned NewOpc = (isThumb2 ? ARM::t2LDMIA_RET : ARM::LDMIA_RET); |
| assert(((isThumb2 && Opcode == ARM::t2LDMIA_UPD) || |
| Opcode == ARM::LDMIA_UPD) && "Unsupported multiple load-return!"); |
| PrevMI->setDesc(TII->get(NewOpc)); |
| MO.setReg(ARM::PC); |
| PrevMI->copyImplicitOps(&*MBBI); |
| MBB.erase(MBBI); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool ARMLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) { |
| const TargetMachine &TM = Fn.getTarget(); |
| AFI = Fn.getInfo<ARMFunctionInfo>(); |
| TII = TM.getInstrInfo(); |
| TRI = TM.getRegisterInfo(); |
| STI = &TM.getSubtarget<ARMSubtarget>(); |
| RS = new RegScavenger(); |
| isThumb2 = AFI->isThumb2Function(); |
| |
| bool Modified = false; |
| for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E; |
| ++MFI) { |
| MachineBasicBlock &MBB = *MFI; |
| Modified |= LoadStoreMultipleOpti(MBB); |
| if (TM.getSubtarget<ARMSubtarget>().hasV5TOps()) |
| Modified |= MergeReturnIntoLDM(MBB); |
| } |
| |
| delete RS; |
| return Modified; |
| } |
| |
| |
| /// ARMPreAllocLoadStoreOpt - Pre- register allocation pass that move |
| /// load / stores from consecutive locations close to make it more |
| /// likely they will be combined later. |
| |
| namespace { |
| struct ARMPreAllocLoadStoreOpt : public MachineFunctionPass{ |
| static char ID; |
| ARMPreAllocLoadStoreOpt() : MachineFunctionPass(ID) {} |
| |
| const TargetData *TD; |
| const TargetInstrInfo *TII; |
| const TargetRegisterInfo *TRI; |
| const ARMSubtarget *STI; |
| MachineRegisterInfo *MRI; |
| MachineFunction *MF; |
| |
| virtual bool runOnMachineFunction(MachineFunction &Fn); |
| |
| virtual const char *getPassName() const { |
| return "ARM pre- register allocation load / store optimization pass"; |
| } |
| |
| private: |
| bool CanFormLdStDWord(MachineInstr *Op0, MachineInstr *Op1, DebugLoc &dl, |
| unsigned &NewOpc, unsigned &EvenReg, |
| unsigned &OddReg, unsigned &BaseReg, |
| int &Offset, |
| unsigned &PredReg, ARMCC::CondCodes &Pred, |
| bool &isT2); |
| bool RescheduleOps(MachineBasicBlock *MBB, |
| SmallVector<MachineInstr*, 4> &Ops, |
| unsigned Base, bool isLd, |
| DenseMap<MachineInstr*, unsigned> &MI2LocMap); |
| bool RescheduleLoadStoreInstrs(MachineBasicBlock *MBB); |
| }; |
| char ARMPreAllocLoadStoreOpt::ID = 0; |
| } |
| |
| bool ARMPreAllocLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) { |
| TD = Fn.getTarget().getTargetData(); |
| TII = Fn.getTarget().getInstrInfo(); |
| TRI = Fn.getTarget().getRegisterInfo(); |
| STI = &Fn.getTarget().getSubtarget<ARMSubtarget>(); |
| MRI = &Fn.getRegInfo(); |
| MF = &Fn; |
| |
| bool Modified = false; |
| for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E; |
| ++MFI) |
| Modified |= RescheduleLoadStoreInstrs(MFI); |
| |
| return Modified; |
| } |
| |
| static bool IsSafeAndProfitableToMove(bool isLd, unsigned Base, |
| MachineBasicBlock::iterator I, |
| MachineBasicBlock::iterator E, |
| SmallPtrSet<MachineInstr*, 4> &MemOps, |
| SmallSet<unsigned, 4> &MemRegs, |
| const TargetRegisterInfo *TRI) { |
| // Are there stores / loads / calls between them? |
| // FIXME: This is overly conservative. We should make use of alias information |
| // some day. |
| SmallSet<unsigned, 4> AddedRegPressure; |
| while (++I != E) { |
| if (I->isDebugValue() || MemOps.count(&*I)) |
| continue; |
| const MCInstrDesc &MCID = I->getDesc(); |
| if (MCID.isCall() || MCID.isTerminator() || I->hasUnmodeledSideEffects()) |
| return false; |
| if (isLd && MCID.mayStore()) |
| return false; |
| if (!isLd) { |
| if (MCID.mayLoad()) |
| return false; |
| // It's not safe to move the first 'str' down. |
| // str r1, [r0] |
| // strh r5, [r0] |
| // str r4, [r0, #+4] |
| if (MCID.mayStore()) |
| return false; |
| } |
| for (unsigned j = 0, NumOps = I->getNumOperands(); j != NumOps; ++j) { |
| MachineOperand &MO = I->getOperand(j); |
| if (!MO.isReg()) |
| continue; |
| unsigned Reg = MO.getReg(); |
| if (MO.isDef() && TRI->regsOverlap(Reg, Base)) |
| return false; |
| if (Reg != Base && !MemRegs.count(Reg)) |
| AddedRegPressure.insert(Reg); |
| } |
| } |
| |
| // Estimate register pressure increase due to the transformation. |
| if (MemRegs.size() <= 4) |
| // Ok if we are moving small number of instructions. |
| return true; |
| return AddedRegPressure.size() <= MemRegs.size() * 2; |
| } |
| |
| |
| /// Copy Op0 and Op1 operands into a new array assigned to MI. |
| static void concatenateMemOperands(MachineInstr *MI, MachineInstr *Op0, |
| MachineInstr *Op1) { |
| assert(MI->memoperands_empty() && "expected a new machineinstr"); |
| size_t numMemRefs = (Op0->memoperands_end() - Op0->memoperands_begin()) |
| + (Op1->memoperands_end() - Op1->memoperands_begin()); |
| |
| MachineFunction *MF = MI->getParent()->getParent(); |
| MachineSDNode::mmo_iterator MemBegin = MF->allocateMemRefsArray(numMemRefs); |
| MachineSDNode::mmo_iterator MemEnd = |
| std::copy(Op0->memoperands_begin(), Op0->memoperands_end(), MemBegin); |
| MemEnd = |
| std::copy(Op1->memoperands_begin(), Op1->memoperands_end(), MemEnd); |
| MI->setMemRefs(MemBegin, MemEnd); |
| } |
| |
| bool |
| ARMPreAllocLoadStoreOpt::CanFormLdStDWord(MachineInstr *Op0, MachineInstr *Op1, |
| DebugLoc &dl, |
| unsigned &NewOpc, unsigned &EvenReg, |
| unsigned &OddReg, unsigned &BaseReg, |
| int &Offset, unsigned &PredReg, |
| ARMCC::CondCodes &Pred, |
| bool &isT2) { |
| // Make sure we're allowed to generate LDRD/STRD. |
| if (!STI->hasV5TEOps()) |
| return false; |
| |
| // FIXME: VLDRS / VSTRS -> VLDRD / VSTRD |
| unsigned Scale = 1; |
| unsigned Opcode = Op0->getOpcode(); |
| if (Opcode == ARM::LDRi12) |
| NewOpc = ARM::LDRD; |
| else if (Opcode == ARM::STRi12) |
| NewOpc = ARM::STRD; |
| else if (Opcode == ARM::t2LDRi8 || Opcode == ARM::t2LDRi12) { |
| NewOpc = ARM::t2LDRDi8; |
| Scale = 4; |
| isT2 = true; |
| } else if (Opcode == ARM::t2STRi8 || Opcode == ARM::t2STRi12) { |
| NewOpc = ARM::t2STRDi8; |
| Scale = 4; |
| isT2 = true; |
| } else |
| return false; |
| |
| // Make sure the base address satisfies i64 ld / st alignment requirement. |
| if (!Op0->hasOneMemOperand() || |
| !(*Op0->memoperands_begin())->getValue() || |
| (*Op0->memoperands_begin())->isVolatile()) |
| return false; |
| |
| unsigned Align = (*Op0->memoperands_begin())->getAlignment(); |
| const Function *Func = MF->getFunction(); |
| unsigned ReqAlign = STI->hasV6Ops() |
| ? TD->getABITypeAlignment(Type::getInt64Ty(Func->getContext())) |
| : 8; // Pre-v6 need 8-byte align |
| if (Align < ReqAlign) |
| return false; |
| |
| // Then make sure the immediate offset fits. |
| int OffImm = getMemoryOpOffset(Op0); |
| if (isT2) { |
| int Limit = (1 << 8) * Scale; |
| if (OffImm >= Limit || (OffImm <= -Limit) || (OffImm & (Scale-1))) |
| return false; |
| Offset = OffImm; |
| } else { |
| ARM_AM::AddrOpc AddSub = ARM_AM::add; |
| if (OffImm < 0) { |
| AddSub = ARM_AM::sub; |
| OffImm = - OffImm; |
| } |
| int Limit = (1 << 8) * Scale; |
| if (OffImm >= Limit || (OffImm & (Scale-1))) |
| return false; |
| Offset = ARM_AM::getAM3Opc(AddSub, OffImm); |
| } |
| EvenReg = Op0->getOperand(0).getReg(); |
| OddReg = Op1->getOperand(0).getReg(); |
| if (EvenReg == OddReg) |
| return false; |
| BaseReg = Op0->getOperand(1).getReg(); |
| Pred = llvm::getInstrPredicate(Op0, PredReg); |
| dl = Op0->getDebugLoc(); |
| return true; |
| } |
| |
| namespace { |
| struct OffsetCompare { |
| bool operator()(const MachineInstr *LHS, const MachineInstr *RHS) const { |
| int LOffset = getMemoryOpOffset(LHS); |
| int ROffset = getMemoryOpOffset(RHS); |
| assert(LHS == RHS || LOffset != ROffset); |
| return LOffset > ROffset; |
| } |
| }; |
| } |
| |
| bool ARMPreAllocLoadStoreOpt::RescheduleOps(MachineBasicBlock *MBB, |
| SmallVector<MachineInstr*, 4> &Ops, |
| unsigned Base, bool isLd, |
| DenseMap<MachineInstr*, unsigned> &MI2LocMap) { |
| bool RetVal = false; |
| |
| // Sort by offset (in reverse order). |
| std::sort(Ops.begin(), Ops.end(), OffsetCompare()); |
| |
| // The loads / stores of the same base are in order. Scan them from first to |
| // last and check for the following: |
| // 1. Any def of base. |
| // 2. Any gaps. |
| while (Ops.size() > 1) { |
| unsigned FirstLoc = ~0U; |
| unsigned LastLoc = 0; |
| MachineInstr *FirstOp = 0; |
| MachineInstr *LastOp = 0; |
| int LastOffset = 0; |
| unsigned LastOpcode = 0; |
| unsigned LastBytes = 0; |
| unsigned NumMove = 0; |
| for (int i = Ops.size() - 1; i >= 0; --i) { |
| MachineInstr *Op = Ops[i]; |
| unsigned Loc = MI2LocMap[Op]; |
| if (Loc <= FirstLoc) { |
| FirstLoc = Loc; |
| FirstOp = Op; |
| } |
| if (Loc >= LastLoc) { |
| LastLoc = Loc; |
| LastOp = Op; |
| } |
| |
| unsigned Opcode = Op->getOpcode(); |
| if (LastOpcode && Opcode != LastOpcode) |
| break; |
| |
| int Offset = getMemoryOpOffset(Op); |
| unsigned Bytes = getLSMultipleTransferSize(Op); |
| if (LastBytes) { |
| if (Bytes != LastBytes || Offset != (LastOffset + (int)Bytes)) |
| break; |
| } |
| LastOffset = Offset; |
| LastBytes = Bytes; |
| LastOpcode = Opcode; |
| if (++NumMove == 8) // FIXME: Tune this limit. |
| break; |
| } |
| |
| if (NumMove <= 1) |
| Ops.pop_back(); |
| else { |
| SmallPtrSet<MachineInstr*, 4> MemOps; |
| SmallSet<unsigned, 4> MemRegs; |
| for (int i = NumMove-1; i >= 0; --i) { |
| MemOps.insert(Ops[i]); |
| MemRegs.insert(Ops[i]->getOperand(0).getReg()); |
| } |
| |
| // Be conservative, if the instructions are too far apart, don't |
| // move them. We want to limit the increase of register pressure. |
| bool DoMove = (LastLoc - FirstLoc) <= NumMove*4; // FIXME: Tune this. |
| if (DoMove) |
| DoMove = IsSafeAndProfitableToMove(isLd, Base, FirstOp, LastOp, |
| MemOps, MemRegs, TRI); |
| if (!DoMove) { |
| for (unsigned i = 0; i != NumMove; ++i) |
| Ops.pop_back(); |
| } else { |
| // This is the new location for the loads / stores. |
| MachineBasicBlock::iterator InsertPos = isLd ? FirstOp : LastOp; |
| while (InsertPos != MBB->end() |
| && (MemOps.count(InsertPos) || InsertPos->isDebugValue())) |
| ++InsertPos; |
| |
| // If we are moving a pair of loads / stores, see if it makes sense |
| // to try to allocate a pair of registers that can form register pairs. |
| MachineInstr *Op0 = Ops.back(); |
| MachineInstr *Op1 = Ops[Ops.size()-2]; |
| unsigned EvenReg = 0, OddReg = 0; |
| unsigned BaseReg = 0, PredReg = 0; |
| ARMCC::CondCodes Pred = ARMCC::AL; |
| bool isT2 = false; |
| unsigned NewOpc = 0; |
| int Offset = 0; |
| DebugLoc dl; |
| if (NumMove == 2 && CanFormLdStDWord(Op0, Op1, dl, NewOpc, |
| EvenReg, OddReg, BaseReg, |
| Offset, PredReg, Pred, isT2)) { |
| Ops.pop_back(); |
| Ops.pop_back(); |
| |
| const MCInstrDesc &MCID = TII->get(NewOpc); |
| const TargetRegisterClass *TRC = TII->getRegClass(MCID, 0, TRI); |
| MRI->constrainRegClass(EvenReg, TRC); |
| MRI->constrainRegClass(OddReg, TRC); |
| |
| // Form the pair instruction. |
| if (isLd) { |
| MachineInstrBuilder MIB = BuildMI(*MBB, InsertPos, dl, MCID) |
| .addReg(EvenReg, RegState::Define) |
| .addReg(OddReg, RegState::Define) |
| .addReg(BaseReg); |
| // FIXME: We're converting from LDRi12 to an insn that still |
| // uses addrmode2, so we need an explicit offset reg. It should |
| // always by reg0 since we're transforming LDRi12s. |
| if (!isT2) |
| MIB.addReg(0); |
| MIB.addImm(Offset).addImm(Pred).addReg(PredReg); |
| concatenateMemOperands(MIB, Op0, Op1); |
| DEBUG(dbgs() << "Formed " << *MIB << "\n"); |
| ++NumLDRDFormed; |
| } else { |
| MachineInstrBuilder MIB = BuildMI(*MBB, InsertPos, dl, MCID) |
| .addReg(EvenReg) |
| .addReg(OddReg) |
| .addReg(BaseReg); |
| // FIXME: We're converting from LDRi12 to an insn that still |
| // uses addrmode2, so we need an explicit offset reg. It should |
| // always by reg0 since we're transforming STRi12s. |
| if (!isT2) |
| MIB.addReg(0); |
| MIB.addImm(Offset).addImm(Pred).addReg(PredReg); |
| concatenateMemOperands(MIB, Op0, Op1); |
| DEBUG(dbgs() << "Formed " << *MIB << "\n"); |
| ++NumSTRDFormed; |
| } |
| MBB->erase(Op0); |
| MBB->erase(Op1); |
| |
| // Add register allocation hints to form register pairs. |
| MRI->setRegAllocationHint(EvenReg, ARMRI::RegPairEven, OddReg); |
| MRI->setRegAllocationHint(OddReg, ARMRI::RegPairOdd, EvenReg); |
| } else { |
| for (unsigned i = 0; i != NumMove; ++i) { |
| MachineInstr *Op = Ops.back(); |
| Ops.pop_back(); |
| MBB->splice(InsertPos, MBB, Op); |
| } |
| } |
| |
| NumLdStMoved += NumMove; |
| RetVal = true; |
| } |
| } |
| } |
| |
| return RetVal; |
| } |
| |
| bool |
| ARMPreAllocLoadStoreOpt::RescheduleLoadStoreInstrs(MachineBasicBlock *MBB) { |
| bool RetVal = false; |
| |
| DenseMap<MachineInstr*, unsigned> MI2LocMap; |
| DenseMap<unsigned, SmallVector<MachineInstr*, 4> > Base2LdsMap; |
| DenseMap<unsigned, SmallVector<MachineInstr*, 4> > Base2StsMap; |
| SmallVector<unsigned, 4> LdBases; |
| SmallVector<unsigned, 4> StBases; |
| |
| unsigned Loc = 0; |
| MachineBasicBlock::iterator MBBI = MBB->begin(); |
| MachineBasicBlock::iterator E = MBB->end(); |
| while (MBBI != E) { |
| for (; MBBI != E; ++MBBI) { |
| MachineInstr *MI = MBBI; |
| const MCInstrDesc &MCID = MI->getDesc(); |
| if (MCID.isCall() || MCID.isTerminator()) { |
| // Stop at barriers. |
| ++MBBI; |
| break; |
| } |
| |
| if (!MI->isDebugValue()) |
| MI2LocMap[MI] = ++Loc; |
| |
| if (!isMemoryOp(MI)) |
| continue; |
| unsigned PredReg = 0; |
| if (llvm::getInstrPredicate(MI, PredReg) != ARMCC::AL) |
| continue; |
| |
| int Opc = MI->getOpcode(); |
| bool isLd = isi32Load(Opc) || Opc == ARM::VLDRS || Opc == ARM::VLDRD; |
| unsigned Base = MI->getOperand(1).getReg(); |
| int Offset = getMemoryOpOffset(MI); |
| |
| bool StopHere = false; |
| if (isLd) { |
| DenseMap<unsigned, SmallVector<MachineInstr*, 4> >::iterator BI = |
| Base2LdsMap.find(Base); |
| if (BI != Base2LdsMap.end()) { |
| for (unsigned i = 0, e = BI->second.size(); i != e; ++i) { |
| if (Offset == getMemoryOpOffset(BI->second[i])) { |
| StopHere = true; |
| break; |
| } |
| } |
| if (!StopHere) |
| BI->second.push_back(MI); |
| } else { |
| SmallVector<MachineInstr*, 4> MIs; |
| MIs.push_back(MI); |
| Base2LdsMap[Base] = MIs; |
| LdBases.push_back(Base); |
| } |
| } else { |
| DenseMap<unsigned, SmallVector<MachineInstr*, 4> >::iterator BI = |
| Base2StsMap.find(Base); |
| if (BI != Base2StsMap.end()) { |
| for (unsigned i = 0, e = BI->second.size(); i != e; ++i) { |
| if (Offset == getMemoryOpOffset(BI->second[i])) { |
| StopHere = true; |
| break; |
| } |
| } |
| if (!StopHere) |
| BI->second.push_back(MI); |
| } else { |
| SmallVector<MachineInstr*, 4> MIs; |
| MIs.push_back(MI); |
| Base2StsMap[Base] = MIs; |
| StBases.push_back(Base); |
| } |
| } |
| |
| if (StopHere) { |
| // Found a duplicate (a base+offset combination that's seen earlier). |
| // Backtrack. |
| --Loc; |
| break; |
| } |
| } |
| |
| // Re-schedule loads. |
| for (unsigned i = 0, e = LdBases.size(); i != e; ++i) { |
| unsigned Base = LdBases[i]; |
| SmallVector<MachineInstr*, 4> &Lds = Base2LdsMap[Base]; |
| if (Lds.size() > 1) |
| RetVal |= RescheduleOps(MBB, Lds, Base, true, MI2LocMap); |
| } |
| |
| // Re-schedule stores. |
| for (unsigned i = 0, e = StBases.size(); i != e; ++i) { |
| unsigned Base = StBases[i]; |
| SmallVector<MachineInstr*, 4> &Sts = Base2StsMap[Base]; |
| if (Sts.size() > 1) |
| RetVal |= RescheduleOps(MBB, Sts, Base, false, MI2LocMap); |
| } |
| |
| if (MBBI != E) { |
| Base2LdsMap.clear(); |
| Base2StsMap.clear(); |
| LdBases.clear(); |
| StBases.clear(); |
| } |
| } |
| |
| return RetVal; |
| } |
| |
| |
| /// createARMLoadStoreOptimizationPass - returns an instance of the load / store |
| /// optimization pass. |
| FunctionPass *llvm::createARMLoadStoreOptimizationPass(bool PreAlloc) { |
| if (PreAlloc) |
| return new ARMPreAllocLoadStoreOpt(); |
| return new ARMLoadStoreOpt(); |
| } |
