| //===- Thumb2InstrInfo.cpp - Thumb-2 Instruction Information --------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains the Thumb-2 implementation of the TargetInstrInfo class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "Thumb2InstrInfo.h" |
| #include "ARMMachineFunctionInfo.h" |
| #include "ARMSubtarget.h" |
| #include "MCTargetDesc/ARMAddressingModes.h" |
| #include "llvm/CodeGen/MachineBasicBlock.h" |
| #include "llvm/CodeGen/MachineFrameInfo.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineMemOperand.h" |
| #include "llvm/CodeGen/MachineOperand.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/CodeGen/TargetRegisterInfo.h" |
| #include "llvm/IR/DebugLoc.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/MC/MCInstBuilder.h" |
| #include "llvm/MC/MCInstrDesc.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/MathExtras.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include <cassert> |
| |
| using namespace llvm; |
| |
| static cl::opt<bool> |
| OldT2IfCvt("old-thumb2-ifcvt", cl::Hidden, |
| cl::desc("Use old-style Thumb2 if-conversion heuristics"), |
| cl::init(false)); |
| |
| static cl::opt<bool> |
| PreferNoCSEL("prefer-no-csel", cl::Hidden, |
| cl::desc("Prefer predicated Move to CSEL"), |
| cl::init(false)); |
| |
| Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI) |
| : ARMBaseInstrInfo(STI) {} |
| |
| /// Return the noop instruction to use for a noop. |
| MCInst Thumb2InstrInfo::getNop() const { |
| return MCInstBuilder(ARM::tHINT).addImm(0).addImm(ARMCC::AL).addReg(0); |
| } |
| |
| unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const { |
| // FIXME |
| return 0; |
| } |
| |
| void |
| Thumb2InstrInfo::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail, |
| MachineBasicBlock *NewDest) const { |
| MachineBasicBlock *MBB = Tail->getParent(); |
| ARMFunctionInfo *AFI = MBB->getParent()->getInfo<ARMFunctionInfo>(); |
| if (!AFI->hasITBlocks() || Tail->isBranch()) { |
| TargetInstrInfo::ReplaceTailWithBranchTo(Tail, NewDest); |
| return; |
| } |
| |
| // If the first instruction of Tail is predicated, we may have to update |
| // the IT instruction. |
| Register PredReg; |
| ARMCC::CondCodes CC = getInstrPredicate(*Tail, PredReg); |
| MachineBasicBlock::iterator MBBI = Tail; |
| if (CC != ARMCC::AL) |
| // Expecting at least the t2IT instruction before it. |
| --MBBI; |
| |
| // Actually replace the tail. |
| TargetInstrInfo::ReplaceTailWithBranchTo(Tail, NewDest); |
| |
| // Fix up IT. |
| if (CC != ARMCC::AL) { |
| MachineBasicBlock::iterator E = MBB->begin(); |
| unsigned Count = 4; // At most 4 instructions in an IT block. |
| while (Count && MBBI != E) { |
| if (MBBI->isDebugInstr()) { |
| --MBBI; |
| continue; |
| } |
| if (MBBI->getOpcode() == ARM::t2IT) { |
| unsigned Mask = MBBI->getOperand(1).getImm(); |
| if (Count == 4) |
| MBBI->eraseFromParent(); |
| else { |
| unsigned MaskOn = 1 << Count; |
| unsigned MaskOff = ~(MaskOn - 1); |
| MBBI->getOperand(1).setImm((Mask & MaskOff) | MaskOn); |
| } |
| return; |
| } |
| --MBBI; |
| --Count; |
| } |
| |
| // Ctrl flow can reach here if branch folding is run before IT block |
| // formation pass. |
| } |
| } |
| |
| bool |
| Thumb2InstrInfo::isLegalToSplitMBBAt(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator MBBI) const { |
| while (MBBI->isDebugInstr()) { |
| ++MBBI; |
| if (MBBI == MBB.end()) |
| return false; |
| } |
| |
| Register PredReg; |
| return getITInstrPredicate(*MBBI, PredReg) == ARMCC::AL; |
| } |
| |
| MachineInstr * |
| Thumb2InstrInfo::optimizeSelect(MachineInstr &MI, |
| SmallPtrSetImpl<MachineInstr *> &SeenMIs, |
| bool PreferFalse) const { |
| // Try to use the base optimizeSelect, which uses canFoldIntoMOVCC to fold the |
| // MOVCC into another instruction. If that fails on 8.1-M fall back to using a |
| // CSEL. |
| MachineInstr *RV = ARMBaseInstrInfo::optimizeSelect(MI, SeenMIs, PreferFalse); |
| if (!RV && getSubtarget().hasV8_1MMainlineOps() && !PreferNoCSEL) { |
| Register DestReg = MI.getOperand(0).getReg(); |
| |
| if (!DestReg.isVirtual()) |
| return nullptr; |
| |
| MachineInstrBuilder NewMI = BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), |
| get(ARM::t2CSEL), DestReg) |
| .add(MI.getOperand(2)) |
| .add(MI.getOperand(1)) |
| .add(MI.getOperand(3)); |
| SeenMIs.insert(NewMI); |
| return NewMI; |
| } |
| return RV; |
| } |
| |
| void Thumb2InstrInfo::copyPhysReg(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator I, |
| const DebugLoc &DL, MCRegister DestReg, |
| MCRegister SrcReg, bool KillSrc) const { |
| // Handle SPR, DPR, and QPR copies. |
| if (!ARM::GPRRegClass.contains(DestReg, SrcReg)) |
| return ARMBaseInstrInfo::copyPhysReg(MBB, I, DL, DestReg, SrcReg, KillSrc); |
| |
| BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg) |
| .addReg(SrcReg, getKillRegState(KillSrc)) |
| .add(predOps(ARMCC::AL)); |
| } |
| |
| void Thumb2InstrInfo:: |
| storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, |
| Register SrcReg, bool isKill, int FI, |
| const TargetRegisterClass *RC, |
| const TargetRegisterInfo *TRI) const { |
| DebugLoc DL; |
| if (I != MBB.end()) DL = I->getDebugLoc(); |
| |
| MachineFunction &MF = *MBB.getParent(); |
| MachineFrameInfo &MFI = MF.getFrameInfo(); |
| MachineMemOperand *MMO = MF.getMachineMemOperand( |
| MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore, |
| MFI.getObjectSize(FI), MFI.getObjectAlign(FI)); |
| |
| if (ARM::GPRRegClass.hasSubClassEq(RC)) { |
| BuildMI(MBB, I, DL, get(ARM::t2STRi12)) |
| .addReg(SrcReg, getKillRegState(isKill)) |
| .addFrameIndex(FI) |
| .addImm(0) |
| .addMemOperand(MMO) |
| .add(predOps(ARMCC::AL)); |
| return; |
| } |
| |
| if (ARM::GPRPairRegClass.hasSubClassEq(RC)) { |
| // Thumb2 STRD expects its dest-registers to be in rGPR. Not a problem for |
| // gsub_0, but needs an extra constraint for gsub_1 (which could be sp |
| // otherwise). |
| if (Register::isVirtualRegister(SrcReg)) { |
| MachineRegisterInfo *MRI = &MF.getRegInfo(); |
| MRI->constrainRegClass(SrcReg, &ARM::GPRPairnospRegClass); |
| } |
| |
| MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::t2STRDi8)); |
| AddDReg(MIB, SrcReg, ARM::gsub_0, getKillRegState(isKill), TRI); |
| AddDReg(MIB, SrcReg, ARM::gsub_1, 0, TRI); |
| MIB.addFrameIndex(FI).addImm(0).addMemOperand(MMO).add(predOps(ARMCC::AL)); |
| return; |
| } |
| |
| ARMBaseInstrInfo::storeRegToStackSlot(MBB, I, SrcReg, isKill, FI, RC, TRI); |
| } |
| |
| void Thumb2InstrInfo:: |
| loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, |
| Register DestReg, int FI, |
| const TargetRegisterClass *RC, |
| const TargetRegisterInfo *TRI) const { |
| MachineFunction &MF = *MBB.getParent(); |
| MachineFrameInfo &MFI = MF.getFrameInfo(); |
| MachineMemOperand *MMO = MF.getMachineMemOperand( |
| MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad, |
| MFI.getObjectSize(FI), MFI.getObjectAlign(FI)); |
| DebugLoc DL; |
| if (I != MBB.end()) DL = I->getDebugLoc(); |
| |
| if (ARM::GPRRegClass.hasSubClassEq(RC)) { |
| BuildMI(MBB, I, DL, get(ARM::t2LDRi12), DestReg) |
| .addFrameIndex(FI) |
| .addImm(0) |
| .addMemOperand(MMO) |
| .add(predOps(ARMCC::AL)); |
| return; |
| } |
| |
| if (ARM::GPRPairRegClass.hasSubClassEq(RC)) { |
| // Thumb2 LDRD expects its dest-registers to be in rGPR. Not a problem for |
| // gsub_0, but needs an extra constraint for gsub_1 (which could be sp |
| // otherwise). |
| if (Register::isVirtualRegister(DestReg)) { |
| MachineRegisterInfo *MRI = &MF.getRegInfo(); |
| MRI->constrainRegClass(DestReg, &ARM::GPRPairnospRegClass); |
| } |
| |
| MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::t2LDRDi8)); |
| AddDReg(MIB, DestReg, ARM::gsub_0, RegState::DefineNoRead, TRI); |
| AddDReg(MIB, DestReg, ARM::gsub_1, RegState::DefineNoRead, TRI); |
| MIB.addFrameIndex(FI).addImm(0).addMemOperand(MMO).add(predOps(ARMCC::AL)); |
| |
| if (Register::isPhysicalRegister(DestReg)) |
| MIB.addReg(DestReg, RegState::ImplicitDefine); |
| return; |
| } |
| |
| ARMBaseInstrInfo::loadRegFromStackSlot(MBB, I, DestReg, FI, RC, TRI); |
| } |
| |
| void Thumb2InstrInfo::expandLoadStackGuard( |
| MachineBasicBlock::iterator MI) const { |
| MachineFunction &MF = *MI->getParent()->getParent(); |
| Module &M = *MF.getFunction().getParent(); |
| |
| if (M.getStackProtectorGuard() == "tls") { |
| expandLoadStackGuardBase(MI, ARM::t2MRC, ARM::t2LDRi12); |
| return; |
| } |
| |
| const GlobalValue *GV = |
| cast<GlobalValue>((*MI->memoperands_begin())->getValue()); |
| |
| if (MF.getSubtarget<ARMSubtarget>().isGVInGOT(GV)) |
| expandLoadStackGuardBase(MI, ARM::t2LDRLIT_ga_pcrel, ARM::t2LDRi12); |
| else if (MF.getTarget().isPositionIndependent()) |
| expandLoadStackGuardBase(MI, ARM::t2MOV_ga_pcrel, ARM::t2LDRi12); |
| else |
| expandLoadStackGuardBase(MI, ARM::t2MOVi32imm, ARM::t2LDRi12); |
| } |
| |
| MachineInstr *Thumb2InstrInfo::commuteInstructionImpl(MachineInstr &MI, |
| bool NewMI, |
| unsigned OpIdx1, |
| unsigned OpIdx2) const { |
| switch (MI.getOpcode()) { |
| case ARM::MVE_VMAXNMAf16: |
| case ARM::MVE_VMAXNMAf32: |
| case ARM::MVE_VMINNMAf16: |
| case ARM::MVE_VMINNMAf32: |
| // Don't allow predicated instructions to be commuted. |
| if (getVPTInstrPredicate(MI) != ARMVCC::None) |
| return nullptr; |
| } |
| return ARMBaseInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2); |
| } |
| |
| void llvm::emitT2RegPlusImmediate(MachineBasicBlock &MBB, |
| MachineBasicBlock::iterator &MBBI, |
| const DebugLoc &dl, Register DestReg, |
| Register BaseReg, int NumBytes, |
| ARMCC::CondCodes Pred, Register PredReg, |
| const ARMBaseInstrInfo &TII, |
| unsigned MIFlags) { |
| if (NumBytes == 0 && DestReg != BaseReg) { |
| BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg) |
| .addReg(BaseReg, RegState::Kill) |
| .addImm((unsigned)Pred).addReg(PredReg).setMIFlags(MIFlags); |
| return; |
| } |
| |
| bool isSub = NumBytes < 0; |
| if (isSub) NumBytes = -NumBytes; |
| |
| // If profitable, use a movw or movt to materialize the offset. |
| // FIXME: Use the scavenger to grab a scratch register. |
| if (DestReg != ARM::SP && DestReg != BaseReg && |
| NumBytes >= 4096 && |
| ARM_AM::getT2SOImmVal(NumBytes) == -1) { |
| bool Fits = false; |
| if (NumBytes < 65536) { |
| // Use a movw to materialize the 16-bit constant. |
| BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVi16), DestReg) |
| .addImm(NumBytes) |
| .addImm((unsigned)Pred).addReg(PredReg).setMIFlags(MIFlags); |
| Fits = true; |
| } else if ((NumBytes & 0xffff) == 0) { |
| // Use a movt to materialize the 32-bit constant. |
| BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVTi16), DestReg) |
| .addReg(DestReg) |
| .addImm(NumBytes >> 16) |
| .addImm((unsigned)Pred).addReg(PredReg).setMIFlags(MIFlags); |
| Fits = true; |
| } |
| |
| if (Fits) { |
| if (isSub) { |
| BuildMI(MBB, MBBI, dl, TII.get(ARM::t2SUBrr), DestReg) |
| .addReg(BaseReg) |
| .addReg(DestReg, RegState::Kill) |
| .add(predOps(Pred, PredReg)) |
| .add(condCodeOp()) |
| .setMIFlags(MIFlags); |
| } else { |
| // Here we know that DestReg is not SP but we do not |
| // know anything about BaseReg. t2ADDrr is an invalid |
| // instruction is SP is used as the second argument, but |
| // is fine if SP is the first argument. To be sure we |
| // do not generate invalid encoding, put BaseReg first. |
| BuildMI(MBB, MBBI, dl, TII.get(ARM::t2ADDrr), DestReg) |
| .addReg(BaseReg) |
| .addReg(DestReg, RegState::Kill) |
| .add(predOps(Pred, PredReg)) |
| .add(condCodeOp()) |
| .setMIFlags(MIFlags); |
| } |
| return; |
| } |
| } |
| |
| while (NumBytes) { |
| unsigned ThisVal = NumBytes; |
| unsigned Opc = 0; |
| if (DestReg == ARM::SP && BaseReg != ARM::SP) { |
| // mov sp, rn. Note t2MOVr cannot be used. |
| BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg) |
| .addReg(BaseReg) |
| .setMIFlags(MIFlags) |
| .add(predOps(ARMCC::AL)); |
| BaseReg = ARM::SP; |
| continue; |
| } |
| |
| assert((DestReg != ARM::SP || BaseReg == ARM::SP) && |
| "Writing to SP, from other register."); |
| |
| // Try to use T1, as it smaller |
| if ((DestReg == ARM::SP) && (ThisVal < ((1 << 7) - 1) * 4)) { |
| assert((ThisVal & 3) == 0 && "Stack update is not multiple of 4?"); |
| Opc = isSub ? ARM::tSUBspi : ARM::tADDspi; |
| BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg) |
| .addReg(BaseReg) |
| .addImm(ThisVal / 4) |
| .setMIFlags(MIFlags) |
| .add(predOps(ARMCC::AL)); |
| break; |
| } |
| bool HasCCOut = true; |
| int ImmIsT2SO = ARM_AM::getT2SOImmVal(ThisVal); |
| bool ToSP = DestReg == ARM::SP; |
| unsigned t2SUB = ToSP ? ARM::t2SUBspImm : ARM::t2SUBri; |
| unsigned t2ADD = ToSP ? ARM::t2ADDspImm : ARM::t2ADDri; |
| unsigned t2SUBi12 = ToSP ? ARM::t2SUBspImm12 : ARM::t2SUBri12; |
| unsigned t2ADDi12 = ToSP ? ARM::t2ADDspImm12 : ARM::t2ADDri12; |
| Opc = isSub ? t2SUB : t2ADD; |
| // Prefer T2: sub rd, rn, so_imm | sub sp, sp, so_imm |
| if (ImmIsT2SO != -1) { |
| NumBytes = 0; |
| } else if (ThisVal < 4096) { |
| // Prefer T3 if can make it in a single go: subw rd, rn, imm12 | subw sp, |
| // sp, imm12 |
| Opc = isSub ? t2SUBi12 : t2ADDi12; |
| HasCCOut = false; |
| NumBytes = 0; |
| } else { |
| // Use one T2 instruction to reduce NumBytes |
| // FIXME: Move this to ARMAddressingModes.h? |
| unsigned RotAmt = countLeadingZeros(ThisVal); |
| ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt); |
| NumBytes &= ~ThisVal; |
| assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 && |
| "Bit extraction didn't work?"); |
| } |
| |
| // Build the new ADD / SUB. |
| MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg) |
| .addReg(BaseReg, RegState::Kill) |
| .addImm(ThisVal) |
| .add(predOps(ARMCC::AL)) |
| .setMIFlags(MIFlags); |
| if (HasCCOut) |
| MIB.add(condCodeOp()); |
| |
| BaseReg = DestReg; |
| } |
| } |
| |
| static unsigned |
| negativeOffsetOpcode(unsigned opcode) |
| { |
| switch (opcode) { |
| case ARM::t2LDRi12: return ARM::t2LDRi8; |
| case ARM::t2LDRHi12: return ARM::t2LDRHi8; |
| case ARM::t2LDRBi12: return ARM::t2LDRBi8; |
| case ARM::t2LDRSHi12: return ARM::t2LDRSHi8; |
| case ARM::t2LDRSBi12: return ARM::t2LDRSBi8; |
| case ARM::t2STRi12: return ARM::t2STRi8; |
| case ARM::t2STRBi12: return ARM::t2STRBi8; |
| case ARM::t2STRHi12: return ARM::t2STRHi8; |
| case ARM::t2PLDi12: return ARM::t2PLDi8; |
| case ARM::t2PLDWi12: return ARM::t2PLDWi8; |
| case ARM::t2PLIi12: return ARM::t2PLIi8; |
| |
| case ARM::t2LDRi8: |
| case ARM::t2LDRHi8: |
| case ARM::t2LDRBi8: |
| case ARM::t2LDRSHi8: |
| case ARM::t2LDRSBi8: |
| case ARM::t2STRi8: |
| case ARM::t2STRBi8: |
| case ARM::t2STRHi8: |
| case ARM::t2PLDi8: |
| case ARM::t2PLDWi8: |
| case ARM::t2PLIi8: |
| return opcode; |
| |
| default: |
| llvm_unreachable("unknown thumb2 opcode."); |
| } |
| } |
| |
| static unsigned |
| positiveOffsetOpcode(unsigned opcode) |
| { |
| switch (opcode) { |
| case ARM::t2LDRi8: return ARM::t2LDRi12; |
| case ARM::t2LDRHi8: return ARM::t2LDRHi12; |
| case ARM::t2LDRBi8: return ARM::t2LDRBi12; |
| case ARM::t2LDRSHi8: return ARM::t2LDRSHi12; |
| case ARM::t2LDRSBi8: return ARM::t2LDRSBi12; |
| case ARM::t2STRi8: return ARM::t2STRi12; |
| case ARM::t2STRBi8: return ARM::t2STRBi12; |
| case ARM::t2STRHi8: return ARM::t2STRHi12; |
| case ARM::t2PLDi8: return ARM::t2PLDi12; |
| case ARM::t2PLDWi8: return ARM::t2PLDWi12; |
| case ARM::t2PLIi8: return ARM::t2PLIi12; |
| |
| case ARM::t2LDRi12: |
| case ARM::t2LDRHi12: |
| case ARM::t2LDRBi12: |
| case ARM::t2LDRSHi12: |
| case ARM::t2LDRSBi12: |
| case ARM::t2STRi12: |
| case ARM::t2STRBi12: |
| case ARM::t2STRHi12: |
| case ARM::t2PLDi12: |
| case ARM::t2PLDWi12: |
| case ARM::t2PLIi12: |
| return opcode; |
| |
| default: |
| llvm_unreachable("unknown thumb2 opcode."); |
| } |
| } |
| |
| static unsigned |
| immediateOffsetOpcode(unsigned opcode) |
| { |
| switch (opcode) { |
| case ARM::t2LDRs: return ARM::t2LDRi12; |
| case ARM::t2LDRHs: return ARM::t2LDRHi12; |
| case ARM::t2LDRBs: return ARM::t2LDRBi12; |
| case ARM::t2LDRSHs: return ARM::t2LDRSHi12; |
| case ARM::t2LDRSBs: return ARM::t2LDRSBi12; |
| case ARM::t2STRs: return ARM::t2STRi12; |
| case ARM::t2STRBs: return ARM::t2STRBi12; |
| case ARM::t2STRHs: return ARM::t2STRHi12; |
| case ARM::t2PLDs: return ARM::t2PLDi12; |
| case ARM::t2PLDWs: return ARM::t2PLDWi12; |
| case ARM::t2PLIs: return ARM::t2PLIi12; |
| |
| case ARM::t2LDRi12: |
| case ARM::t2LDRHi12: |
| case ARM::t2LDRBi12: |
| case ARM::t2LDRSHi12: |
| case ARM::t2LDRSBi12: |
| case ARM::t2STRi12: |
| case ARM::t2STRBi12: |
| case ARM::t2STRHi12: |
| case ARM::t2PLDi12: |
| case ARM::t2PLDWi12: |
| case ARM::t2PLIi12: |
| case ARM::t2LDRi8: |
| case ARM::t2LDRHi8: |
| case ARM::t2LDRBi8: |
| case ARM::t2LDRSHi8: |
| case ARM::t2LDRSBi8: |
| case ARM::t2STRi8: |
| case ARM::t2STRBi8: |
| case ARM::t2STRHi8: |
| case ARM::t2PLDi8: |
| case ARM::t2PLDWi8: |
| case ARM::t2PLIi8: |
| return opcode; |
| |
| default: |
| llvm_unreachable("unknown thumb2 opcode."); |
| } |
| } |
| |
| bool llvm::rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx, |
| Register FrameReg, int &Offset, |
| const ARMBaseInstrInfo &TII, |
| const TargetRegisterInfo *TRI) { |
| unsigned Opcode = MI.getOpcode(); |
| const MCInstrDesc &Desc = MI.getDesc(); |
| unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); |
| bool isSub = false; |
| |
| MachineFunction &MF = *MI.getParent()->getParent(); |
| const TargetRegisterClass *RegClass = |
| TII.getRegClass(Desc, FrameRegIdx, TRI, MF); |
| |
| // Memory operands in inline assembly always use AddrModeT2_i12. |
| if (Opcode == ARM::INLINEASM || Opcode == ARM::INLINEASM_BR) |
| AddrMode = ARMII::AddrModeT2_i12; // FIXME. mode for thumb2? |
| |
| const bool IsSP = Opcode == ARM::t2ADDspImm12 || Opcode == ARM::t2ADDspImm; |
| if (IsSP || Opcode == ARM::t2ADDri || Opcode == ARM::t2ADDri12) { |
| Offset += MI.getOperand(FrameRegIdx+1).getImm(); |
| |
| Register PredReg; |
| if (Offset == 0 && getInstrPredicate(MI, PredReg) == ARMCC::AL && |
| !MI.definesRegister(ARM::CPSR)) { |
| // Turn it into a move. |
| MI.setDesc(TII.get(ARM::tMOVr)); |
| MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); |
| // Remove offset and remaining explicit predicate operands. |
| do MI.RemoveOperand(FrameRegIdx+1); |
| while (MI.getNumOperands() > FrameRegIdx+1); |
| MachineInstrBuilder MIB(*MI.getParent()->getParent(), &MI); |
| MIB.add(predOps(ARMCC::AL)); |
| return true; |
| } |
| |
| bool HasCCOut = (Opcode != ARM::t2ADDspImm12 && Opcode != ARM::t2ADDri12); |
| |
| if (Offset < 0) { |
| Offset = -Offset; |
| isSub = true; |
| MI.setDesc(IsSP ? TII.get(ARM::t2SUBspImm) : TII.get(ARM::t2SUBri)); |
| } else { |
| MI.setDesc(IsSP ? TII.get(ARM::t2ADDspImm) : TII.get(ARM::t2ADDri)); |
| } |
| |
| // Common case: small offset, fits into instruction. |
| if (ARM_AM::getT2SOImmVal(Offset) != -1) { |
| MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); |
| MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset); |
| // Add cc_out operand if the original instruction did not have one. |
| if (!HasCCOut) |
| MI.addOperand(MachineOperand::CreateReg(0, false)); |
| Offset = 0; |
| return true; |
| } |
| // Another common case: imm12. |
| if (Offset < 4096 && |
| (!HasCCOut || MI.getOperand(MI.getNumOperands()-1).getReg() == 0)) { |
| unsigned NewOpc = isSub ? IsSP ? ARM::t2SUBspImm12 : ARM::t2SUBri12 |
| : IsSP ? ARM::t2ADDspImm12 : ARM::t2ADDri12; |
| MI.setDesc(TII.get(NewOpc)); |
| MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); |
| MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset); |
| // Remove the cc_out operand. |
| if (HasCCOut) |
| MI.RemoveOperand(MI.getNumOperands()-1); |
| Offset = 0; |
| return true; |
| } |
| |
| // Otherwise, extract 8 adjacent bits from the immediate into this |
| // t2ADDri/t2SUBri. |
| unsigned RotAmt = countLeadingZeros<unsigned>(Offset); |
| unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xff000000U, RotAmt); |
| |
| // We will handle these bits from offset, clear them. |
| Offset &= ~ThisImmVal; |
| |
| assert(ARM_AM::getT2SOImmVal(ThisImmVal) != -1 && |
| "Bit extraction didn't work?"); |
| MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal); |
| // Add cc_out operand if the original instruction did not have one. |
| if (!HasCCOut) |
| MI.addOperand(MachineOperand::CreateReg(0, false)); |
| } else { |
| // AddrMode4 and AddrMode6 cannot handle any offset. |
| if (AddrMode == ARMII::AddrMode4 || AddrMode == ARMII::AddrMode6) |
| return false; |
| |
| // AddrModeT2_so cannot handle any offset. If there is no offset |
| // register then we change to an immediate version. |
| unsigned NewOpc = Opcode; |
| if (AddrMode == ARMII::AddrModeT2_so) { |
| Register OffsetReg = MI.getOperand(FrameRegIdx + 1).getReg(); |
| if (OffsetReg != 0) { |
| MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); |
| return Offset == 0; |
| } |
| |
| MI.RemoveOperand(FrameRegIdx+1); |
| MI.getOperand(FrameRegIdx+1).ChangeToImmediate(0); |
| NewOpc = immediateOffsetOpcode(Opcode); |
| AddrMode = ARMII::AddrModeT2_i12; |
| } |
| |
| unsigned NumBits = 0; |
| unsigned Scale = 1; |
| if (AddrMode == ARMII::AddrModeT2_i8 || AddrMode == ARMII::AddrModeT2_i12) { |
| // i8 supports only negative, and i12 supports only positive, so |
| // based on Offset sign convert Opcode to the appropriate |
| // instruction |
| Offset += MI.getOperand(FrameRegIdx+1).getImm(); |
| if (Offset < 0) { |
| NewOpc = negativeOffsetOpcode(Opcode); |
| NumBits = 8; |
| isSub = true; |
| Offset = -Offset; |
| } else { |
| NewOpc = positiveOffsetOpcode(Opcode); |
| NumBits = 12; |
| } |
| } else if (AddrMode == ARMII::AddrMode5) { |
| // VFP address mode. |
| const MachineOperand &OffOp = MI.getOperand(FrameRegIdx+1); |
| int InstrOffs = ARM_AM::getAM5Offset(OffOp.getImm()); |
| if (ARM_AM::getAM5Op(OffOp.getImm()) == ARM_AM::sub) |
| InstrOffs *= -1; |
| NumBits = 8; |
| Scale = 4; |
| Offset += InstrOffs * 4; |
| assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!"); |
| if (Offset < 0) { |
| Offset = -Offset; |
| isSub = true; |
| } |
| } else if (AddrMode == ARMII::AddrMode5FP16) { |
| // VFP address mode. |
| const MachineOperand &OffOp = MI.getOperand(FrameRegIdx+1); |
| int InstrOffs = ARM_AM::getAM5FP16Offset(OffOp.getImm()); |
| if (ARM_AM::getAM5FP16Op(OffOp.getImm()) == ARM_AM::sub) |
| InstrOffs *= -1; |
| NumBits = 8; |
| Scale = 2; |
| Offset += InstrOffs * 2; |
| assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!"); |
| if (Offset < 0) { |
| Offset = -Offset; |
| isSub = true; |
| } |
| } else if (AddrMode == ARMII::AddrModeT2_i7s4 || |
| AddrMode == ARMII::AddrModeT2_i7s2 || |
| AddrMode == ARMII::AddrModeT2_i7) { |
| Offset += MI.getOperand(FrameRegIdx + 1).getImm(); |
| unsigned OffsetMask; |
| switch (AddrMode) { |
| case ARMII::AddrModeT2_i7s4: NumBits = 9; OffsetMask = 0x3; break; |
| case ARMII::AddrModeT2_i7s2: NumBits = 8; OffsetMask = 0x1; break; |
| default: NumBits = 7; OffsetMask = 0x0; break; |
| } |
| // MCInst operand expects already scaled value. |
| Scale = 1; |
| assert((Offset & OffsetMask) == 0 && "Can't encode this offset!"); |
| (void)OffsetMask; // squash unused-variable warning at -NDEBUG |
| } else if (AddrMode == ARMII::AddrModeT2_i8s4) { |
| Offset += MI.getOperand(FrameRegIdx + 1).getImm(); |
| NumBits = 8 + 2; |
| // MCInst operand expects already scaled value. |
| Scale = 1; |
| assert((Offset & 3) == 0 && "Can't encode this offset!"); |
| } else if (AddrMode == ARMII::AddrModeT2_ldrex) { |
| Offset += MI.getOperand(FrameRegIdx + 1).getImm() * 4; |
| NumBits = 8; // 8 bits scaled by 4 |
| Scale = 4; |
| assert((Offset & 3) == 0 && "Can't encode this offset!"); |
| } else { |
| llvm_unreachable("Unsupported addressing mode!"); |
| } |
| |
| if (NewOpc != Opcode) |
| MI.setDesc(TII.get(NewOpc)); |
| |
| MachineOperand &ImmOp = MI.getOperand(FrameRegIdx+1); |
| |
| // Attempt to fold address computation |
| // Common case: small offset, fits into instruction. We need to make sure |
| // the register class is correct too, for instructions like the MVE |
| // VLDRH.32, which only accepts low tGPR registers. |
| int ImmedOffset = Offset / Scale; |
| unsigned Mask = (1 << NumBits) - 1; |
| if ((unsigned)Offset <= Mask * Scale && |
| (Register::isVirtualRegister(FrameReg) || |
| RegClass->contains(FrameReg))) { |
| if (Register::isVirtualRegister(FrameReg)) { |
| // Make sure the register class for the virtual register is correct |
| MachineRegisterInfo *MRI = &MF.getRegInfo(); |
| if (!MRI->constrainRegClass(FrameReg, RegClass)) |
| llvm_unreachable("Unable to constrain virtual register class."); |
| } |
| |
| // Replace the FrameIndex with fp/sp |
| MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false); |
| if (isSub) { |
| if (AddrMode == ARMII::AddrMode5 || AddrMode == ARMII::AddrMode5FP16) |
| // FIXME: Not consistent. |
| ImmedOffset |= 1 << NumBits; |
| else |
| ImmedOffset = -ImmedOffset; |
| } |
| ImmOp.ChangeToImmediate(ImmedOffset); |
| Offset = 0; |
| return true; |
| } |
| |
| // Otherwise, offset doesn't fit. Pull in what we can to simplify |
| ImmedOffset = ImmedOffset & Mask; |
| if (isSub) { |
| if (AddrMode == ARMII::AddrMode5 || AddrMode == ARMII::AddrMode5FP16) |
| // FIXME: Not consistent. |
| ImmedOffset |= 1 << NumBits; |
| else { |
| ImmedOffset = -ImmedOffset; |
| if (ImmedOffset == 0) |
| // Change the opcode back if the encoded offset is zero. |
| MI.setDesc(TII.get(positiveOffsetOpcode(NewOpc))); |
| } |
| } |
| ImmOp.ChangeToImmediate(ImmedOffset); |
| Offset &= ~(Mask*Scale); |
| } |
| |
| Offset = (isSub) ? -Offset : Offset; |
| return Offset == 0 && (Register::isVirtualRegister(FrameReg) || |
| RegClass->contains(FrameReg)); |
| } |
| |
| ARMCC::CondCodes llvm::getITInstrPredicate(const MachineInstr &MI, |
| Register &PredReg) { |
| unsigned Opc = MI.getOpcode(); |
| if (Opc == ARM::tBcc || Opc == ARM::t2Bcc) |
| return ARMCC::AL; |
| return getInstrPredicate(MI, PredReg); |
| } |
| |
| int llvm::findFirstVPTPredOperandIdx(const MachineInstr &MI) { |
| const MCInstrDesc &MCID = MI.getDesc(); |
| |
| if (!MCID.OpInfo) |
| return -1; |
| |
| for (unsigned i = 0, e = MCID.getNumOperands(); i != e; ++i) |
| if (ARM::isVpred(MCID.OpInfo[i].OperandType)) |
| return i; |
| |
| return -1; |
| } |
| |
| ARMVCC::VPTCodes llvm::getVPTInstrPredicate(const MachineInstr &MI, |
| Register &PredReg) { |
| int PIdx = findFirstVPTPredOperandIdx(MI); |
| if (PIdx == -1) { |
| PredReg = 0; |
| return ARMVCC::None; |
| } |
| |
| PredReg = MI.getOperand(PIdx+1).getReg(); |
| return (ARMVCC::VPTCodes)MI.getOperand(PIdx).getImm(); |
| } |
| |
| void llvm::recomputeVPTBlockMask(MachineInstr &Instr) { |
| assert(isVPTOpcode(Instr.getOpcode()) && "Not a VPST or VPT Instruction!"); |
| |
| MachineOperand &MaskOp = Instr.getOperand(0); |
| assert(MaskOp.isImm() && "Operand 0 is not the block mask of the VPT/VPST?!"); |
| |
| MachineBasicBlock::iterator Iter = ++Instr.getIterator(), |
| End = Instr.getParent()->end(); |
| |
| while (Iter != End && Iter->isDebugInstr()) |
| ++Iter; |
| |
| // Verify that the instruction after the VPT/VPST is predicated (it should |
| // be), and skip it. |
| assert(Iter != End && "Expected some instructions in any VPT block"); |
| assert( |
| getVPTInstrPredicate(*Iter) == ARMVCC::Then && |
| "VPT/VPST should be followed by an instruction with a 'then' predicate!"); |
| ++Iter; |
| |
| // Iterate over the predicated instructions, updating the BlockMask as we go. |
| ARM::PredBlockMask BlockMask = ARM::PredBlockMask::T; |
| while (Iter != End) { |
| if (Iter->isDebugInstr()) { |
| ++Iter; |
| continue; |
| } |
| ARMVCC::VPTCodes Pred = getVPTInstrPredicate(*Iter); |
| if (Pred == ARMVCC::None) |
| break; |
| BlockMask = expandPredBlockMask(BlockMask, Pred); |
| ++Iter; |
| } |
| |
| // Rewrite the BlockMask. |
| MaskOp.setImm((int64_t)(BlockMask)); |
| } |
