X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTarget%2FARM%2FARMLoadStoreOptimizer.cpp;h=9dc74a185aef47473e1c59eea103d71dff6867b7;hb=12af22e8cc217827cf4f118b0f5e4ebbda9925ae;hp=5b678bd2799753f0f77b9f42041ff989ee1be3fa;hpb=2c9f8a715ed61a68eff0f4310254d24e16594d39;p=oota-llvm.git diff --git a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp index 5b678bd2799..9dc74a185ae 100644 --- a/lib/Target/ARM/ARMLoadStoreOptimizer.cpp +++ b/lib/Target/ARM/ARMLoadStoreOptimizer.cpp @@ -15,9 +15,11 @@ #include "ARM.h" #include "ARMBaseInstrInfo.h" #include "ARMBaseRegisterInfo.h" +#include "ARMISelLowering.h" #include "ARMMachineFunctionInfo.h" #include "ARMSubtarget.h" #include "MCTargetDesc/ARMAddressingModes.h" +#include "Thumb1RegisterInfo.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallPtrSet.h" @@ -66,6 +68,7 @@ namespace { const TargetInstrInfo *TII; const TargetRegisterInfo *TRI; const ARMSubtarget *STI; + const TargetLowering *TL; ARMFunctionInfo *AFI; RegScavenger *RS; bool isThumb1, isThumb2; @@ -94,7 +97,6 @@ namespace { void findUsesOfImpDef(SmallVectorImpl &UsesOfImpDefs, const MemOpQueue &MemOps, unsigned DefReg, unsigned RangeBegin, unsigned RangeEnd); - bool MergeOps(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, int Offset, unsigned Base, bool BaseKill, int Opcode, ARMCC::CondCodes Pred, unsigned PredReg, unsigned Scratch, @@ -120,7 +122,6 @@ namespace { ARMCC::CondCodes Pred, unsigned PredReg, unsigned Scratch, MemOpQueue &MemOps, SmallVectorImpl &Merges); - void AdvanceRS(MachineBasicBlock &MBB, MemOpQueue &MemOps); bool FixInvalidRegPairOp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI); @@ -160,6 +161,21 @@ static int getLoadStoreMultipleOpcode(int Opcode, ARM_AM::AMSubMode Mode) { case ARM_AM::db: return ARM::STMDB; case ARM_AM::ib: return ARM::STMIB; } + case ARM::tLDRi: + // tLDMIA is writeback-only - unless the base register is in the input + // reglist. + ++NumLDMGened; + switch (Mode) { + default: llvm_unreachable("Unhandled submode!"); + case ARM_AM::ia: return ARM::tLDMIA; + } + case ARM::tSTRi: + // There is no non-writeback tSTMIA either. + ++NumSTMGened; + switch (Mode) { + default: llvm_unreachable("Unhandled submode!"); + case ARM_AM::ia: return ARM::tSTMIA_UPD; + } case ARM::t2LDRi8: case ARM::t2LDRi12: ++NumLDMGened; @@ -218,6 +234,9 @@ AMSubMode getLoadStoreMultipleSubMode(int Opcode) { case ARM::LDMIA_UPD: case ARM::STMIA: case ARM::STMIA_UPD: + case ARM::tLDMIA: + case ARM::tLDMIA_UPD: + case ARM::tSTMIA_UPD: case ARM::t2LDMIA_RET: case ARM::t2LDMIA: case ARM::t2LDMIA_UPD: @@ -264,12 +283,20 @@ AMSubMode getLoadStoreMultipleSubMode(int Opcode) { } // end namespace ARM_AM } // end namespace llvm +static bool isT1i32Load(unsigned Opc) { + return Opc == ARM::tLDRi; +} + static bool isT2i32Load(unsigned Opc) { return Opc == ARM::t2LDRi12 || Opc == ARM::t2LDRi8; } static bool isi32Load(unsigned Opc) { - return Opc == ARM::LDRi12 || isT2i32Load(Opc); + return Opc == ARM::LDRi12 || isT1i32Load(Opc) || isT2i32Load(Opc) ; +} + +static bool isT1i32Store(unsigned Opc) { + return Opc == ARM::tSTRi; } static bool isT2i32Store(unsigned Opc) { @@ -277,7 +304,7 @@ static bool isT2i32Store(unsigned Opc) { } static bool isi32Store(unsigned Opc) { - return Opc == ARM::STRi12 || isT2i32Store(Opc); + return Opc == ARM::STRi12 || isT1i32Store(Opc) || isT2i32Store(Opc); } /// MergeOps - Create and insert a LDM or STM with Base as base register and @@ -297,14 +324,15 @@ ARMLoadStoreOpt::MergeOps(MachineBasicBlock &MBB, return false; ARM_AM::AMSubMode Mode = ARM_AM::ia; - // VFP and Thumb2 do not support IB or DA modes. + // VFP and Thumb2 do not support IB or DA modes. Thumb1 only supports IA. bool isNotVFP = isi32Load(Opcode) || isi32Store(Opcode); - bool haveIBAndDA = isNotVFP && !isThumb2; + bool haveIBAndDA = isNotVFP && !isThumb2 && !isThumb1; + 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) { + } else if (Offset == -4 * (int)NumRegs && isNotVFP && !isThumb1) { // VLDM/VSTM do not support DB mode without also updating the base reg. Mode = ARM_AM::db; } else if (Offset != 0) { @@ -329,31 +357,98 @@ ARMLoadStoreOpt::MergeOps(MachineBasicBlock &MBB, if (NewBase == 0) return false; } - int BaseOpc = !isThumb2 ? ARM::ADDri : ARM::t2ADDri; + + int BaseOpc = + isThumb2 ? ARM::t2ADDri : + (isThumb1 && Offset < 8) ? ARM::tADDi3 : + isThumb1 ? ARM::tADDi8 : ARM::ADDri; + if (Offset < 0) { - BaseOpc = !isThumb2 ? ARM::SUBri : ARM::t2SUBri; Offset = - Offset; + BaseOpc = + isThumb2 ? ARM::t2SUBri : + (isThumb1 && Offset < 8) ? ARM::tSUBi3 : + isThumb1 ? ARM::tSUBi8 : ARM::SUBri; + } + + if (!TL->isLegalAddImmediate(Offset)) + // FIXME: Try add with register operand? + return false; // Probably not worth it then. + + if (isThumb1) { + // Thumb1: depending on immediate size, use either + // ADD NewBase, Base, #imm3 + // or + // MOV NewBase, Base + // ADD NewBase, #imm8. + if (Base != NewBase && Offset >= 8) { + // Need to insert a MOV to the new base first. + BuildMI(MBB, MBBI, dl, TII->get(ARM::tMOVr), NewBase) + .addReg(Base, getKillRegState(BaseKill)) + .addImm(Pred).addReg(PredReg); + // Set up BaseKill and Base correctly to insert the ADDS/SUBS below. + Base = NewBase; + BaseKill = false; + } + AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII->get(BaseOpc), NewBase)) + .addReg(Base, getKillRegState(BaseKill)).addImm(Offset) + .addImm(Pred).addReg(PredReg); + } else { + BuildMI(MBB, MBBI, dl, TII->get(BaseOpc), NewBase) + .addReg(Base, getKillRegState(BaseKill)).addImm(Offset) + .addImm(Pred).addReg(PredReg).addReg(0); } - 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 straight away. } bool isDef = (isi32Load(Opcode) || Opcode == ARM::VLDRS || Opcode == ARM::VLDRD); + + // Get LS multiple opcode. Note that for Thumb1 this might be an opcode with + // base register writeback. 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); + + bool Writeback = isThumb1; // Thumb1 LDM/STM have base reg writeback. + + // Exception: If the base register is in the input reglist, Thumb1 LDM is + // non-writeback. Check for this. + if (Opcode == ARM::tLDMIA && isThumb1) + for (unsigned I = 0; I < NumRegs; ++I) + if (Base == Regs[I].first) { + Writeback = false; + break; + } + + // If the merged instruction has writeback and the base register is not killed + // it's not safe to do the merge on Thumb1. This is because resetting the base + // register writeback by inserting a SUBS sets the condition flags. + // FIXME: Try something clever here to see if resetting the base register can + // be avoided, e.g. by updating a later ADD/SUB of the base register with the + // writeback. + if (isThumb1 && Writeback && !BaseKill) return false; + + MachineInstrBuilder MIB; + + if (Writeback) { + if (Opcode == ARM::tLDMIA) + // Update tLDMIA with writeback if necessary. + Opcode = ARM::tLDMIA_UPD; + + MIB = BuildMI(MBB, MBBI, dl, TII->get(Opcode)); + + // Thumb1: we might need to set base writeback when building the MI. + MIB.addReg(Base, getDefRegState(true)) + .addReg(Base, getKillRegState(BaseKill)); + } else { + // No writeback, simply build the MachineInstr. + MIB = BuildMI(MBB, MBBI, dl, TII->get(Opcode)); + MIB.addReg(Base, getKillRegState(BaseKill)); + } + + MIB.addImm(Pred).addReg(PredReg); + for (unsigned i = 0; i != NumRegs; ++i) MIB = MIB.addReg(Regs[i].first, getDefRegState(isDef) | getKillRegState(Regs[i].second)); @@ -537,7 +632,7 @@ ARMLoadStoreOpt::MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex, unsigned PRegNum = PMO.isUndef() ? UINT_MAX : TRI->getEncodingValue(PReg); unsigned Count = 1; unsigned Limit = ~0U; - + bool BaseKill = false; // vldm / vstm limit are 32 for S variants, 16 for D variants. switch (Opcode) { @@ -576,18 +671,24 @@ ARMLoadStoreOpt::MergeLDR_STR(MachineBasicBlock &MBB, unsigned SIndex, ++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); + // We need to compute BaseKill here because the MemOps may have been + // reordered. + BaseKill = Loc->killsRegister(Base); + + MergeOpsUpdate(MBB, MemOps, SIndex, i, insertAfter, SOffset, Base, + BaseKill, 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) + if (MemOps[i].Position > MemOps[insertAfter].Position) { insertAfter = i; + Loc = MemOps[i].MBBI; + } } - bool BaseKill = Loc->findRegisterUseOperandIdx(Base, true) != -1; + BaseKill = Loc->killsRegister(Base); MergeOpsUpdate(MBB, MemOps, SIndex, MemOps.size(), insertAfter, SOffset, Base, BaseKill, Opcode, Pred, PredReg, Scratch, dl, Merges); } @@ -616,6 +717,7 @@ static bool isMatchingDecrement(MachineInstr *MI, unsigned Base, bool CheckCPSRDef = false; switch (MI->getOpcode()) { default: return false; + case ARM::tSUBi8: case ARM::t2SUBri: case ARM::SUBri: CheckCPSRDef = true; @@ -628,10 +730,11 @@ static bool isMatchingDecrement(MachineInstr *MI, unsigned Base, if (Bytes == 0 || (Limit && Bytes >= Limit)) return false; - unsigned Scale = (MI->getOpcode() == ARM::tSUBspi) ? 4 : 1; // FIXME + unsigned Scale = (MI->getOpcode() == ARM::tSUBspi || + MI->getOpcode() == ARM::tSUBi8) ? 4 : 1; // FIXME if (!(MI->getOperand(0).getReg() == Base && MI->getOperand(1).getReg() == Base && - (MI->getOperand(2).getImm()*Scale) == Bytes && + (MI->getOperand(2).getImm() * Scale) == Bytes && getInstrPredicate(MI, MyPredReg) == Pred && MyPredReg == PredReg)) return false; @@ -649,6 +752,7 @@ static bool isMatchingIncrement(MachineInstr *MI, unsigned Base, bool CheckCPSRDef = false; switch (MI->getOpcode()) { default: return false; + case ARM::tADDi8: case ARM::t2ADDri: case ARM::ADDri: CheckCPSRDef = true; @@ -661,10 +765,11 @@ static bool isMatchingIncrement(MachineInstr *MI, unsigned Base, // Make sure the offset fits in 8 bits. return false; - unsigned Scale = (MI->getOpcode() == ARM::tADDspi) ? 4 : 1; // FIXME + unsigned Scale = (MI->getOpcode() == ARM::tADDspi || + MI->getOpcode() == ARM::tADDi8) ? 4 : 1; // FIXME if (!(MI->getOperand(0).getReg() == Base && MI->getOperand(1).getReg() == Base && - (MI->getOperand(2).getImm()*Scale) == Bytes && + (MI->getOperand(2).getImm() * Scale) == Bytes && getInstrPredicate(MI, MyPredReg) == Pred && MyPredReg == PredReg)) return false; @@ -677,6 +782,8 @@ static inline unsigned getLSMultipleTransferSize(MachineInstr *MI) { default: return 0; case ARM::LDRi12: case ARM::STRi12: + case ARM::tLDRi: + case ARM::tSTRi: case ARM::t2LDRi8: case ARM::t2LDRi12: case ARM::t2STRi8: @@ -695,6 +802,9 @@ static inline unsigned getLSMultipleTransferSize(MachineInstr *MI) { case ARM::STMDA: case ARM::STMDB: case ARM::STMIB: + case ARM::tLDMIA: + case ARM::tLDMIA_UPD: + case ARM::tSTMIA_UPD: case ARM::t2LDMIA: case ARM::t2LDMDB: case ARM::t2STMIA: @@ -791,6 +901,9 @@ bool ARMLoadStoreOpt::MergeBaseUpdateLSMultiple(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, bool &Advance, MachineBasicBlock::iterator &I) { + // Thumb1 is already using updating loads/stores. + if (isThumb1) return false; + MachineInstr *MI = MBBI; unsigned Base = MI->getOperand(0).getReg(); bool BaseKill = MI->getOperand(0).isKill(); @@ -927,6 +1040,10 @@ bool ARMLoadStoreOpt::MergeBaseUpdateLoadStore(MachineBasicBlock &MBB, const TargetInstrInfo *TII, bool &Advance, MachineBasicBlock::iterator &I) { + // Thumb1 doesn't have updating LDR/STR. + // FIXME: Use LDM/STM with single register instead. + if (isThumb1) return false; + MachineInstr *MI = MBBI; unsigned Base = MI->getOperand(1).getReg(); bool BaseKill = MI->getOperand(1).isKill(); @@ -1100,6 +1217,8 @@ static bool isMemoryOp(const MachineInstr *MI) { return MI->getOperand(1).isReg(); case ARM::LDRi12: case ARM::STRi12: + case ARM::tLDRi: + case ARM::tSTRi: case ARM::t2LDRi8: case ARM::t2LDRi12: case ARM::t2STRi8: @@ -1137,6 +1256,10 @@ static int getMemoryOpOffset(const MachineInstr *MI) { Opcode == ARM::LDRi12 || Opcode == ARM::STRi12) return OffField; + // Thumb1 immediate offsets are scaled by 4 + if (Opcode == ARM::tLDRi || Opcode == ARM::tSTRi) + return OffField * 4; + int Offset = isAM3 ? ARM_AM::getAM3Offset(OffField) : ARM_AM::getAM5Offset(OffField) * 4; if (isAM3) { @@ -1417,8 +1540,11 @@ bool ARMLoadStoreOpt::LoadStoreMultipleOpti(MachineBasicBlock &MBB) { // 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::GPRRegClass); + unsigned Scratch = + RS->FindUnusedReg(isThumb1 ? &ARM::tGPRRegClass : &ARM::GPRRegClass); + // Process the load / store instructions. RS->forward(std::prev(MBBI)); @@ -1484,6 +1610,8 @@ bool ARMLoadStoreOpt::LoadStoreMultipleOpti(MachineBasicBlock &MBB) { /// => /// ldmfd sp!, {..., pc} bool ARMLoadStoreOpt::MergeReturnIntoLDM(MachineBasicBlock &MBB) { + // Thumb1 LDM doesn't allow high registers. + if (isThumb1) return false; if (MBB.empty()) return false; MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); @@ -1514,17 +1642,15 @@ bool ARMLoadStoreOpt::MergeReturnIntoLDM(MachineBasicBlock &MBB) { bool ARMLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) { const TargetMachine &TM = Fn.getTarget(); + TL = TM.getSubtargetImpl()->getTargetLowering(); AFI = Fn.getInfo(); - TII = TM.getInstrInfo(); - TRI = TM.getRegisterInfo(); + TII = TM.getSubtargetImpl()->getInstrInfo(); + TRI = TM.getSubtargetImpl()->getRegisterInfo(); STI = &TM.getSubtarget(); RS = new RegScavenger(); isThumb2 = AFI->isThumb2Function(); isThumb1 = AFI->isThumbFunction() && !isThumb2; - // Don't do anything in this pass with Thumb1 for now. - if (isThumb1) return false; - bool Modified = false; for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E; ++MFI) { @@ -1578,18 +1704,13 @@ namespace { } bool ARMPreAllocLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) { - TD = Fn.getTarget().getDataLayout(); - TII = Fn.getTarget().getInstrInfo(); - TRI = Fn.getTarget().getRegisterInfo(); + TD = Fn.getSubtarget().getDataLayout(); + TII = Fn.getSubtarget().getInstrInfo(); + TRI = Fn.getSubtarget().getRegisterInfo(); STI = &Fn.getTarget().getSubtarget(); MRI = &Fn.getRegInfo(); MF = &Fn; - ARMFunctionInfo *AFI = Fn.getInfo(); - bool isThumb1 = AFI->isThumbFunction() && !AFI->isThumb2Function(); - // Don't do anything in this pass with Thumb1 for now. - if (isThumb1) return false; - bool Modified = false; for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E; ++MFI) @@ -1601,7 +1722,7 @@ bool ARMPreAllocLoadStoreOpt::runOnMachineFunction(MachineFunction &Fn) { static bool IsSafeAndProfitableToMove(bool isLd, unsigned Base, MachineBasicBlock::iterator I, MachineBasicBlock::iterator E, - SmallPtrSet &MemOps, + SmallPtrSetImpl &MemOps, SmallSet &MemRegs, const TargetRegisterInfo *TRI) { // Are there stores / loads / calls between them?