//===- AArch64ExpandPseudoInsts.cpp - Expand pseudo instructions ----------===// // // 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 a pass that expands pseudo instructions into target // instructions to allow proper scheduling and other late optimizations. This // pass should be run after register allocation but before the post-regalloc // scheduling pass. // //===----------------------------------------------------------------------===// #include "AArch64ExpandImm.h" #include "AArch64InstrInfo.h" #include "AArch64MachineFunctionInfo.h" #include "AArch64Subtarget.h" #include "MCTargetDesc/AArch64AddressingModes.h" #include "Utils/AArch64BaseInfo.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/Triple.h" #include "llvm/CodeGen/LivePhysRegs.h" #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/MachineInstr.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineOperand.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/IR/DebugLoc.h" #include "llvm/MC/MCInstrDesc.h" #include "llvm/Pass.h" #include "llvm/Support/CodeGen.h" #include "llvm/Support/MathExtras.h" #include "llvm/Target/TargetMachine.h" #include #include #include #include #include using namespace llvm; #define AARCH64_EXPAND_PSEUDO_NAME "AArch64 pseudo instruction expansion pass" namespace { class AArch64ExpandPseudo : public MachineFunctionPass { public: const AArch64InstrInfo *TII; static char ID; AArch64ExpandPseudo() : MachineFunctionPass(ID) { initializeAArch64ExpandPseudoPass(*PassRegistry::getPassRegistry()); } bool runOnMachineFunction(MachineFunction &Fn) override; StringRef getPassName() const override { return AARCH64_EXPAND_PSEUDO_NAME; } private: bool expandMBB(MachineBasicBlock &MBB); bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, MachineBasicBlock::iterator &NextMBBI); bool expandMOVImm(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned BitSize); bool expand_DestructiveOp(MachineInstr &MI, MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI); bool expandCMP_SWAP(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned LdarOp, unsigned StlrOp, unsigned CmpOp, unsigned ExtendImm, unsigned ZeroReg, MachineBasicBlock::iterator &NextMBBI); bool expandCMP_SWAP_128(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, MachineBasicBlock::iterator &NextMBBI); bool expandSetTagLoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, MachineBasicBlock::iterator &NextMBBI); bool expandSVESpillFill(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned Opc, unsigned N); }; } // end anonymous namespace char AArch64ExpandPseudo::ID = 0; INITIALIZE_PASS(AArch64ExpandPseudo, "aarch64-expand-pseudo", AARCH64_EXPAND_PSEUDO_NAME, false, false) /// Transfer implicit operands on the pseudo instruction to the /// instructions created from the expansion. static void transferImpOps(MachineInstr &OldMI, MachineInstrBuilder &UseMI, MachineInstrBuilder &DefMI) { const MCInstrDesc &Desc = OldMI.getDesc(); for (unsigned i = Desc.getNumOperands(), e = OldMI.getNumOperands(); i != e; ++i) { const MachineOperand &MO = OldMI.getOperand(i); assert(MO.isReg() && MO.getReg()); if (MO.isUse()) UseMI.add(MO); else DefMI.add(MO); } } /// Expand a MOVi32imm or MOVi64imm pseudo instruction to one or more /// real move-immediate instructions to synthesize the immediate. bool AArch64ExpandPseudo::expandMOVImm(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned BitSize) { MachineInstr &MI = *MBBI; Register DstReg = MI.getOperand(0).getReg(); uint64_t RenamableState = MI.getOperand(0).isRenamable() ? RegState::Renamable : 0; uint64_t Imm = MI.getOperand(1).getImm(); if (DstReg == AArch64::XZR || DstReg == AArch64::WZR) { // Useless def, and we don't want to risk creating an invalid ORR (which // would really write to sp). MI.eraseFromParent(); return true; } SmallVector Insn; AArch64_IMM::expandMOVImm(Imm, BitSize, Insn); assert(Insn.size() != 0); SmallVector MIBS; for (auto I = Insn.begin(), E = Insn.end(); I != E; ++I) { bool LastItem = std::next(I) == E; switch (I->Opcode) { default: llvm_unreachable("unhandled!"); break; case AArch64::ORRWri: case AArch64::ORRXri: MIBS.push_back(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(I->Opcode)) .add(MI.getOperand(0)) .addReg(BitSize == 32 ? AArch64::WZR : AArch64::XZR) .addImm(I->Op2)); break; case AArch64::MOVNWi: case AArch64::MOVNXi: case AArch64::MOVZWi: case AArch64::MOVZXi: { bool DstIsDead = MI.getOperand(0).isDead(); MIBS.push_back(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(I->Opcode)) .addReg(DstReg, RegState::Define | getDeadRegState(DstIsDead && LastItem) | RenamableState) .addImm(I->Op1) .addImm(I->Op2)); } break; case AArch64::MOVKWi: case AArch64::MOVKXi: { Register DstReg = MI.getOperand(0).getReg(); bool DstIsDead = MI.getOperand(0).isDead(); MIBS.push_back(BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(I->Opcode)) .addReg(DstReg, RegState::Define | getDeadRegState(DstIsDead && LastItem) | RenamableState) .addReg(DstReg) .addImm(I->Op1) .addImm(I->Op2)); } break; } } transferImpOps(MI, MIBS.front(), MIBS.back()); MI.eraseFromParent(); return true; } bool AArch64ExpandPseudo::expandCMP_SWAP( MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned LdarOp, unsigned StlrOp, unsigned CmpOp, unsigned ExtendImm, unsigned ZeroReg, MachineBasicBlock::iterator &NextMBBI) { MachineInstr &MI = *MBBI; DebugLoc DL = MI.getDebugLoc(); const MachineOperand &Dest = MI.getOperand(0); Register StatusReg = MI.getOperand(1).getReg(); bool StatusDead = MI.getOperand(1).isDead(); // Duplicating undef operands into 2 instructions does not guarantee the same // value on both; However undef should be replaced by xzr anyway. assert(!MI.getOperand(2).isUndef() && "cannot handle undef"); Register AddrReg = MI.getOperand(2).getReg(); Register DesiredReg = MI.getOperand(3).getReg(); Register NewReg = MI.getOperand(4).getReg(); MachineFunction *MF = MBB.getParent(); auto LoadCmpBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); auto StoreBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); auto DoneBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); MF->insert(++MBB.getIterator(), LoadCmpBB); MF->insert(++LoadCmpBB->getIterator(), StoreBB); MF->insert(++StoreBB->getIterator(), DoneBB); // .Lloadcmp: // mov wStatus, 0 // ldaxr xDest, [xAddr] // cmp xDest, xDesired // b.ne .Ldone if (!StatusDead) BuildMI(LoadCmpBB, DL, TII->get(AArch64::MOVZWi), StatusReg) .addImm(0).addImm(0); BuildMI(LoadCmpBB, DL, TII->get(LdarOp), Dest.getReg()) .addReg(AddrReg); BuildMI(LoadCmpBB, DL, TII->get(CmpOp), ZeroReg) .addReg(Dest.getReg(), getKillRegState(Dest.isDead())) .addReg(DesiredReg) .addImm(ExtendImm); BuildMI(LoadCmpBB, DL, TII->get(AArch64::Bcc)) .addImm(AArch64CC::NE) .addMBB(DoneBB) .addReg(AArch64::NZCV, RegState::Implicit | RegState::Kill); LoadCmpBB->addSuccessor(DoneBB); LoadCmpBB->addSuccessor(StoreBB); // .Lstore: // stlxr wStatus, xNew, [xAddr] // cbnz wStatus, .Lloadcmp BuildMI(StoreBB, DL, TII->get(StlrOp), StatusReg) .addReg(NewReg) .addReg(AddrReg); BuildMI(StoreBB, DL, TII->get(AArch64::CBNZW)) .addReg(StatusReg, getKillRegState(StatusDead)) .addMBB(LoadCmpBB); StoreBB->addSuccessor(LoadCmpBB); StoreBB->addSuccessor(DoneBB); DoneBB->splice(DoneBB->end(), &MBB, MI, MBB.end()); DoneBB->transferSuccessors(&MBB); MBB.addSuccessor(LoadCmpBB); NextMBBI = MBB.end(); MI.eraseFromParent(); // Recompute livein lists. LivePhysRegs LiveRegs; computeAndAddLiveIns(LiveRegs, *DoneBB); computeAndAddLiveIns(LiveRegs, *StoreBB); computeAndAddLiveIns(LiveRegs, *LoadCmpBB); // Do an extra pass around the loop to get loop carried registers right. StoreBB->clearLiveIns(); computeAndAddLiveIns(LiveRegs, *StoreBB); LoadCmpBB->clearLiveIns(); computeAndAddLiveIns(LiveRegs, *LoadCmpBB); return true; } bool AArch64ExpandPseudo::expandCMP_SWAP_128( MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, MachineBasicBlock::iterator &NextMBBI) { MachineInstr &MI = *MBBI; DebugLoc DL = MI.getDebugLoc(); MachineOperand &DestLo = MI.getOperand(0); MachineOperand &DestHi = MI.getOperand(1); Register StatusReg = MI.getOperand(2).getReg(); bool StatusDead = MI.getOperand(2).isDead(); // Duplicating undef operands into 2 instructions does not guarantee the same // value on both; However undef should be replaced by xzr anyway. assert(!MI.getOperand(3).isUndef() && "cannot handle undef"); Register AddrReg = MI.getOperand(3).getReg(); Register DesiredLoReg = MI.getOperand(4).getReg(); Register DesiredHiReg = MI.getOperand(5).getReg(); Register NewLoReg = MI.getOperand(6).getReg(); Register NewHiReg = MI.getOperand(7).getReg(); MachineFunction *MF = MBB.getParent(); auto LoadCmpBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); auto StoreBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); auto DoneBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); MF->insert(++MBB.getIterator(), LoadCmpBB); MF->insert(++LoadCmpBB->getIterator(), StoreBB); MF->insert(++StoreBB->getIterator(), DoneBB); // .Lloadcmp: // ldaxp xDestLo, xDestHi, [xAddr] // cmp xDestLo, xDesiredLo // sbcs xDestHi, xDesiredHi // b.ne .Ldone BuildMI(LoadCmpBB, DL, TII->get(AArch64::LDAXPX)) .addReg(DestLo.getReg(), RegState::Define) .addReg(DestHi.getReg(), RegState::Define) .addReg(AddrReg); BuildMI(LoadCmpBB, DL, TII->get(AArch64::SUBSXrs), AArch64::XZR) .addReg(DestLo.getReg(), getKillRegState(DestLo.isDead())) .addReg(DesiredLoReg) .addImm(0); BuildMI(LoadCmpBB, DL, TII->get(AArch64::CSINCWr), StatusReg) .addUse(AArch64::WZR) .addUse(AArch64::WZR) .addImm(AArch64CC::EQ); BuildMI(LoadCmpBB, DL, TII->get(AArch64::SUBSXrs), AArch64::XZR) .addReg(DestHi.getReg(), getKillRegState(DestHi.isDead())) .addReg(DesiredHiReg) .addImm(0); BuildMI(LoadCmpBB, DL, TII->get(AArch64::CSINCWr), StatusReg) .addUse(StatusReg, RegState::Kill) .addUse(StatusReg, RegState::Kill) .addImm(AArch64CC::EQ); BuildMI(LoadCmpBB, DL, TII->get(AArch64::CBNZW)) .addUse(StatusReg, getKillRegState(StatusDead)) .addMBB(DoneBB); LoadCmpBB->addSuccessor(DoneBB); LoadCmpBB->addSuccessor(StoreBB); // .Lstore: // stlxp wStatus, xNewLo, xNewHi, [xAddr] // cbnz wStatus, .Lloadcmp BuildMI(StoreBB, DL, TII->get(AArch64::STLXPX), StatusReg) .addReg(NewLoReg) .addReg(NewHiReg) .addReg(AddrReg); BuildMI(StoreBB, DL, TII->get(AArch64::CBNZW)) .addReg(StatusReg, getKillRegState(StatusDead)) .addMBB(LoadCmpBB); StoreBB->addSuccessor(LoadCmpBB); StoreBB->addSuccessor(DoneBB); DoneBB->splice(DoneBB->end(), &MBB, MI, MBB.end()); DoneBB->transferSuccessors(&MBB); MBB.addSuccessor(LoadCmpBB); NextMBBI = MBB.end(); MI.eraseFromParent(); // Recompute liveness bottom up. LivePhysRegs LiveRegs; computeAndAddLiveIns(LiveRegs, *DoneBB); computeAndAddLiveIns(LiveRegs, *StoreBB); computeAndAddLiveIns(LiveRegs, *LoadCmpBB); // Do an extra pass in the loop to get the loop carried dependencies right. StoreBB->clearLiveIns(); computeAndAddLiveIns(LiveRegs, *StoreBB); LoadCmpBB->clearLiveIns(); computeAndAddLiveIns(LiveRegs, *LoadCmpBB); return true; } /// \brief Expand Pseudos to Instructions with destructive operands. /// /// This mechanism uses MOVPRFX instructions for zeroing the false lanes /// or for fixing relaxed register allocation conditions to comply with /// the instructions register constraints. The latter case may be cheaper /// than setting the register constraints in the register allocator, /// since that will insert regular MOV instructions rather than MOVPRFX. /// /// Example (after register allocation): /// /// FSUB_ZPZZ_ZERO_B Z0, Pg, Z1, Z0 /// /// * The Pseudo FSUB_ZPZZ_ZERO_B maps to FSUB_ZPmZ_B. /// * We cannot map directly to FSUB_ZPmZ_B because the register /// constraints of the instruction are not met. /// * Also the _ZERO specifies the false lanes need to be zeroed. /// /// We first try to see if the destructive operand == result operand, /// if not, we try to swap the operands, e.g. /// /// FSUB_ZPmZ_B Z0, Pg/m, Z0, Z1 /// /// But because FSUB_ZPmZ is not commutative, this is semantically /// different, so we need a reverse instruction: /// /// FSUBR_ZPmZ_B Z0, Pg/m, Z0, Z1 /// /// Then we implement the zeroing of the false lanes of Z0 by adding /// a zeroing MOVPRFX instruction: /// /// MOVPRFX_ZPzZ_B Z0, Pg/z, Z0 /// FSUBR_ZPmZ_B Z0, Pg/m, Z0, Z1 /// /// Note that this can only be done for _ZERO or _UNDEF variants where /// we can guarantee the false lanes to be zeroed (by implementing this) /// or that they are undef (don't care / not used), otherwise the /// swapping of operands is illegal because the operation is not /// (or cannot be emulated to be) fully commutative. bool AArch64ExpandPseudo::expand_DestructiveOp( MachineInstr &MI, MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI) { unsigned Opcode = AArch64::getSVEPseudoMap(MI.getOpcode()); uint64_t DType = TII->get(Opcode).TSFlags & AArch64::DestructiveInstTypeMask; uint64_t FalseLanes = MI.getDesc().TSFlags & AArch64::FalseLanesMask; bool FalseZero = FalseLanes == AArch64::FalseLanesZero; unsigned DstReg = MI.getOperand(0).getReg(); bool DstIsDead = MI.getOperand(0).isDead(); if (DType == AArch64::DestructiveBinary) assert(DstReg != MI.getOperand(3).getReg()); bool UseRev = false; unsigned PredIdx, DOPIdx, SrcIdx; switch (DType) { case AArch64::DestructiveBinaryComm: case AArch64::DestructiveBinaryCommWithRev: if (DstReg == MI.getOperand(3).getReg()) { // FSUB Zd, Pg, Zs1, Zd ==> FSUBR Zd, Pg/m, Zd, Zs1 std::tie(PredIdx, DOPIdx, SrcIdx) = std::make_tuple(1, 3, 2); UseRev = true; break; } LLVM_FALLTHROUGH; case AArch64::DestructiveBinary: case AArch64::DestructiveBinaryImm: std::tie(PredIdx, DOPIdx, SrcIdx) = std::make_tuple(1, 2, 3); break; default: llvm_unreachable("Unsupported Destructive Operand type"); } #ifndef NDEBUG // MOVPRFX can only be used if the destination operand // is the destructive operand, not as any other operand, // so the Destructive Operand must be unique. bool DOPRegIsUnique = false; switch (DType) { case AArch64::DestructiveBinaryComm: case AArch64::DestructiveBinaryCommWithRev: DOPRegIsUnique = DstReg != MI.getOperand(DOPIdx).getReg() || MI.getOperand(DOPIdx).getReg() != MI.getOperand(SrcIdx).getReg(); break; case AArch64::DestructiveBinaryImm: DOPRegIsUnique = true; break; } #endif // Resolve the reverse opcode if (UseRev) { int NewOpcode; // e.g. DIV -> DIVR if ((NewOpcode = AArch64::getSVERevInstr(Opcode)) != -1) Opcode = NewOpcode; // e.g. DIVR -> DIV else if ((NewOpcode = AArch64::getSVENonRevInstr(Opcode)) != -1) Opcode = NewOpcode; } // Get the right MOVPRFX uint64_t ElementSize = TII->getElementSizeForOpcode(Opcode); unsigned MovPrfx, MovPrfxZero; switch (ElementSize) { case AArch64::ElementSizeNone: case AArch64::ElementSizeB: MovPrfx = AArch64::MOVPRFX_ZZ; MovPrfxZero = AArch64::MOVPRFX_ZPzZ_B; break; case AArch64::ElementSizeH: MovPrfx = AArch64::MOVPRFX_ZZ; MovPrfxZero = AArch64::MOVPRFX_ZPzZ_H; break; case AArch64::ElementSizeS: MovPrfx = AArch64::MOVPRFX_ZZ; MovPrfxZero = AArch64::MOVPRFX_ZPzZ_S; break; case AArch64::ElementSizeD: MovPrfx = AArch64::MOVPRFX_ZZ; MovPrfxZero = AArch64::MOVPRFX_ZPzZ_D; break; default: llvm_unreachable("Unsupported ElementSize"); } // // Create the destructive operation (if required) // MachineInstrBuilder PRFX, DOP; if (FalseZero) { #ifndef NDEBUG assert(DOPRegIsUnique && "The destructive operand should be unique"); #endif assert(ElementSize != AArch64::ElementSizeNone && "This instruction is unpredicated"); // Merge source operand into destination register PRFX = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(MovPrfxZero)) .addReg(DstReg, RegState::Define) .addReg(MI.getOperand(PredIdx).getReg()) .addReg(MI.getOperand(DOPIdx).getReg()); // After the movprfx, the destructive operand is same as Dst DOPIdx = 0; } else if (DstReg != MI.getOperand(DOPIdx).getReg()) { #ifndef NDEBUG assert(DOPRegIsUnique && "The destructive operand should be unique"); #endif PRFX = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(MovPrfx)) .addReg(DstReg, RegState::Define) .addReg(MI.getOperand(DOPIdx).getReg()); DOPIdx = 0; } // // Create the destructive operation // DOP = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode)) .addReg(DstReg, RegState::Define | getDeadRegState(DstIsDead)); switch (DType) { case AArch64::DestructiveBinaryImm: case AArch64::DestructiveBinaryComm: case AArch64::DestructiveBinaryCommWithRev: DOP.add(MI.getOperand(PredIdx)) .addReg(MI.getOperand(DOPIdx).getReg(), RegState::Kill) .add(MI.getOperand(SrcIdx)); break; } if (PRFX) { finalizeBundle(MBB, PRFX->getIterator(), MBBI->getIterator()); transferImpOps(MI, PRFX, DOP); } else transferImpOps(MI, DOP, DOP); MI.eraseFromParent(); return true; } bool AArch64ExpandPseudo::expandSetTagLoop( MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, MachineBasicBlock::iterator &NextMBBI) { MachineInstr &MI = *MBBI; DebugLoc DL = MI.getDebugLoc(); Register SizeReg = MI.getOperand(0).getReg(); Register AddressReg = MI.getOperand(1).getReg(); MachineFunction *MF = MBB.getParent(); bool ZeroData = MI.getOpcode() == AArch64::STZGloop_wback; const unsigned OpCode1 = ZeroData ? AArch64::STZGPostIndex : AArch64::STGPostIndex; const unsigned OpCode2 = ZeroData ? AArch64::STZ2GPostIndex : AArch64::ST2GPostIndex; unsigned Size = MI.getOperand(2).getImm(); assert(Size > 0 && Size % 16 == 0); if (Size % (16 * 2) != 0) { BuildMI(MBB, MBBI, DL, TII->get(OpCode1), AddressReg) .addReg(AddressReg) .addReg(AddressReg) .addImm(1); Size -= 16; } MachineBasicBlock::iterator I = BuildMI(MBB, MBBI, DL, TII->get(AArch64::MOVi64imm), SizeReg) .addImm(Size); expandMOVImm(MBB, I, 64); auto LoopBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); auto DoneBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock()); MF->insert(++MBB.getIterator(), LoopBB); MF->insert(++LoopBB->getIterator(), DoneBB); BuildMI(LoopBB, DL, TII->get(OpCode2)) .addDef(AddressReg) .addReg(AddressReg) .addReg(AddressReg) .addImm(2) .cloneMemRefs(MI) .setMIFlags(MI.getFlags()); BuildMI(LoopBB, DL, TII->get(AArch64::SUBXri)) .addDef(SizeReg) .addReg(SizeReg) .addImm(16 * 2) .addImm(0); BuildMI(LoopBB, DL, TII->get(AArch64::CBNZX)).addUse(SizeReg).addMBB(LoopBB); LoopBB->addSuccessor(LoopBB); LoopBB->addSuccessor(DoneBB); DoneBB->splice(DoneBB->end(), &MBB, MI, MBB.end()); DoneBB->transferSuccessors(&MBB); MBB.addSuccessor(LoopBB); NextMBBI = MBB.end(); MI.eraseFromParent(); // Recompute liveness bottom up. LivePhysRegs LiveRegs; computeAndAddLiveIns(LiveRegs, *DoneBB); computeAndAddLiveIns(LiveRegs, *LoopBB); // Do an extra pass in the loop to get the loop carried dependencies right. // FIXME: is this necessary? LoopBB->clearLiveIns(); computeAndAddLiveIns(LiveRegs, *LoopBB); DoneBB->clearLiveIns(); computeAndAddLiveIns(LiveRegs, *DoneBB); return true; } bool AArch64ExpandPseudo::expandSVESpillFill(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, unsigned Opc, unsigned N) { const TargetRegisterInfo *TRI = MBB.getParent()->getSubtarget().getRegisterInfo(); MachineInstr &MI = *MBBI; for (unsigned Offset = 0; Offset < N; ++Offset) { int ImmOffset = MI.getOperand(2).getImm() + Offset; bool Kill = (Offset + 1 == N) ? MI.getOperand(1).isKill() : false; assert(ImmOffset >= -256 && ImmOffset < 256 && "Immediate spill offset out of range"); BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opc)) .addReg( TRI->getSubReg(MI.getOperand(0).getReg(), AArch64::zsub0 + Offset), Opc == AArch64::LDR_ZXI ? RegState::Define : 0) .addReg(MI.getOperand(1).getReg(), getKillRegState(Kill)) .addImm(ImmOffset); } MI.eraseFromParent(); return true; } /// If MBBI references a pseudo instruction that should be expanded here, /// do the expansion and return true. Otherwise return false. bool AArch64ExpandPseudo::expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, MachineBasicBlock::iterator &NextMBBI) { MachineInstr &MI = *MBBI; unsigned Opcode = MI.getOpcode(); // Check if we can expand the destructive op int OrigInstr = AArch64::getSVEPseudoMap(MI.getOpcode()); if (OrigInstr != -1) { auto &Orig = TII->get(OrigInstr); if ((Orig.TSFlags & AArch64::DestructiveInstTypeMask) != AArch64::NotDestructive) { return expand_DestructiveOp(MI, MBB, MBBI); } } switch (Opcode) { default: break; case AArch64::BSPv8i8: case AArch64::BSPv16i8: { Register DstReg = MI.getOperand(0).getReg(); if (DstReg == MI.getOperand(3).getReg()) { // Expand to BIT BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode == AArch64::BSPv8i8 ? AArch64::BITv8i8 : AArch64::BITv16i8)) .add(MI.getOperand(0)) .add(MI.getOperand(3)) .add(MI.getOperand(2)) .add(MI.getOperand(1)); } else if (DstReg == MI.getOperand(2).getReg()) { // Expand to BIF BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode == AArch64::BSPv8i8 ? AArch64::BIFv8i8 : AArch64::BIFv16i8)) .add(MI.getOperand(0)) .add(MI.getOperand(2)) .add(MI.getOperand(3)) .add(MI.getOperand(1)); } else { // Expand to BSL, use additional move if required if (DstReg == MI.getOperand(1).getReg()) { BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode == AArch64::BSPv8i8 ? AArch64::BSLv8i8 : AArch64::BSLv16i8)) .add(MI.getOperand(0)) .add(MI.getOperand(1)) .add(MI.getOperand(2)) .add(MI.getOperand(3)); } else { BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode == AArch64::BSPv8i8 ? AArch64::ORRv8i8 : AArch64::ORRv16i8)) .addReg(DstReg, RegState::Define | getRenamableRegState(MI.getOperand(0).isRenamable())) .add(MI.getOperand(1)) .add(MI.getOperand(1)); BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode == AArch64::BSPv8i8 ? AArch64::BSLv8i8 : AArch64::BSLv16i8)) .add(MI.getOperand(0)) .addReg(DstReg, RegState::Kill | getRenamableRegState(MI.getOperand(0).isRenamable())) .add(MI.getOperand(2)) .add(MI.getOperand(3)); } } MI.eraseFromParent(); return true; } case AArch64::ADDWrr: case AArch64::SUBWrr: case AArch64::ADDXrr: case AArch64::SUBXrr: case AArch64::ADDSWrr: case AArch64::SUBSWrr: case AArch64::ADDSXrr: case AArch64::SUBSXrr: case AArch64::ANDWrr: case AArch64::ANDXrr: case AArch64::BICWrr: case AArch64::BICXrr: case AArch64::ANDSWrr: case AArch64::ANDSXrr: case AArch64::BICSWrr: case AArch64::BICSXrr: case AArch64::EONWrr: case AArch64::EONXrr: case AArch64::EORWrr: case AArch64::EORXrr: case AArch64::ORNWrr: case AArch64::ORNXrr: case AArch64::ORRWrr: case AArch64::ORRXrr: { unsigned Opcode; switch (MI.getOpcode()) { default: return false; case AArch64::ADDWrr: Opcode = AArch64::ADDWrs; break; case AArch64::SUBWrr: Opcode = AArch64::SUBWrs; break; case AArch64::ADDXrr: Opcode = AArch64::ADDXrs; break; case AArch64::SUBXrr: Opcode = AArch64::SUBXrs; break; case AArch64::ADDSWrr: Opcode = AArch64::ADDSWrs; break; case AArch64::SUBSWrr: Opcode = AArch64::SUBSWrs; break; case AArch64::ADDSXrr: Opcode = AArch64::ADDSXrs; break; case AArch64::SUBSXrr: Opcode = AArch64::SUBSXrs; break; case AArch64::ANDWrr: Opcode = AArch64::ANDWrs; break; case AArch64::ANDXrr: Opcode = AArch64::ANDXrs; break; case AArch64::BICWrr: Opcode = AArch64::BICWrs; break; case AArch64::BICXrr: Opcode = AArch64::BICXrs; break; case AArch64::ANDSWrr: Opcode = AArch64::ANDSWrs; break; case AArch64::ANDSXrr: Opcode = AArch64::ANDSXrs; break; case AArch64::BICSWrr: Opcode = AArch64::BICSWrs; break; case AArch64::BICSXrr: Opcode = AArch64::BICSXrs; break; case AArch64::EONWrr: Opcode = AArch64::EONWrs; break; case AArch64::EONXrr: Opcode = AArch64::EONXrs; break; case AArch64::EORWrr: Opcode = AArch64::EORWrs; break; case AArch64::EORXrr: Opcode = AArch64::EORXrs; break; case AArch64::ORNWrr: Opcode = AArch64::ORNWrs; break; case AArch64::ORNXrr: Opcode = AArch64::ORNXrs; break; case AArch64::ORRWrr: Opcode = AArch64::ORRWrs; break; case AArch64::ORRXrr: Opcode = AArch64::ORRXrs; break; } MachineInstrBuilder MIB1 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode), MI.getOperand(0).getReg()) .add(MI.getOperand(1)) .add(MI.getOperand(2)) .addImm(AArch64_AM::getShifterImm(AArch64_AM::LSL, 0)); transferImpOps(MI, MIB1, MIB1); MI.eraseFromParent(); return true; } case AArch64::LOADgot: { MachineFunction *MF = MBB.getParent(); Register DstReg = MI.getOperand(0).getReg(); const MachineOperand &MO1 = MI.getOperand(1); unsigned Flags = MO1.getTargetFlags(); if (MF->getTarget().getCodeModel() == CodeModel::Tiny) { // Tiny codemodel expand to LDR MachineInstrBuilder MIB = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::LDRXl), DstReg); if (MO1.isGlobal()) { MIB.addGlobalAddress(MO1.getGlobal(), 0, Flags); } else if (MO1.isSymbol()) { MIB.addExternalSymbol(MO1.getSymbolName(), Flags); } else { assert(MO1.isCPI() && "Only expect globals, externalsymbols, or constant pools"); MIB.addConstantPoolIndex(MO1.getIndex(), MO1.getOffset(), Flags); } } else { // Small codemodel expand into ADRP + LDR. MachineFunction &MF = *MI.getParent()->getParent(); DebugLoc DL = MI.getDebugLoc(); MachineInstrBuilder MIB1 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::ADRP), DstReg); MachineInstrBuilder MIB2; if (MF.getSubtarget().isTargetILP32()) { auto TRI = MBB.getParent()->getSubtarget().getRegisterInfo(); unsigned Reg32 = TRI->getSubReg(DstReg, AArch64::sub_32); unsigned DstFlags = MI.getOperand(0).getTargetFlags(); MIB2 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::LDRWui)) .addDef(Reg32) .addReg(DstReg, RegState::Kill) .addReg(DstReg, DstFlags | RegState::Implicit); } else { unsigned DstReg = MI.getOperand(0).getReg(); MIB2 = BuildMI(MBB, MBBI, DL, TII->get(AArch64::LDRXui)) .add(MI.getOperand(0)) .addUse(DstReg, RegState::Kill); } if (MO1.isGlobal()) { MIB1.addGlobalAddress(MO1.getGlobal(), 0, Flags | AArch64II::MO_PAGE); MIB2.addGlobalAddress(MO1.getGlobal(), 0, Flags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC); } else if (MO1.isSymbol()) { MIB1.addExternalSymbol(MO1.getSymbolName(), Flags | AArch64II::MO_PAGE); MIB2.addExternalSymbol(MO1.getSymbolName(), Flags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC); } else { assert(MO1.isCPI() && "Only expect globals, externalsymbols, or constant pools"); MIB1.addConstantPoolIndex(MO1.getIndex(), MO1.getOffset(), Flags | AArch64II::MO_PAGE); MIB2.addConstantPoolIndex(MO1.getIndex(), MO1.getOffset(), Flags | AArch64II::MO_PAGEOFF | AArch64II::MO_NC); } transferImpOps(MI, MIB1, MIB2); } MI.eraseFromParent(); return true; } case AArch64::MOVaddr: case AArch64::MOVaddrJT: case AArch64::MOVaddrCP: case AArch64::MOVaddrBA: case AArch64::MOVaddrTLS: case AArch64::MOVaddrEXT: { // Expand into ADRP + ADD. Register DstReg = MI.getOperand(0).getReg(); MachineInstrBuilder MIB1 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::ADRP), DstReg) .add(MI.getOperand(1)); if (MI.getOperand(1).getTargetFlags() & AArch64II::MO_TAGGED) { // MO_TAGGED on the page indicates a tagged address. Set the tag now. // We do so by creating a MOVK that sets bits 48-63 of the register to // (global address + 0x100000000 - PC) >> 48. This assumes that we're in // the small code model so we can assume a binary size of <= 4GB, which // makes the untagged PC relative offset positive. The binary must also be // loaded into address range [0, 2^48). Both of these properties need to // be ensured at runtime when using tagged addresses. auto Tag = MI.getOperand(1); Tag.setTargetFlags(AArch64II::MO_PREL | AArch64II::MO_G3); Tag.setOffset(0x100000000); BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::MOVKXi), DstReg) .addReg(DstReg) .add(Tag) .addImm(48); } MachineInstrBuilder MIB2 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::ADDXri)) .add(MI.getOperand(0)) .addReg(DstReg) .add(MI.getOperand(2)) .addImm(0); transferImpOps(MI, MIB1, MIB2); MI.eraseFromParent(); return true; } case AArch64::ADDlowTLS: // Produce a plain ADD BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::ADDXri)) .add(MI.getOperand(0)) .add(MI.getOperand(1)) .add(MI.getOperand(2)) .addImm(0); MI.eraseFromParent(); return true; case AArch64::MOVbaseTLS: { Register DstReg = MI.getOperand(0).getReg(); auto SysReg = AArch64SysReg::TPIDR_EL0; MachineFunction *MF = MBB.getParent(); if (MF->getSubtarget().useEL3ForTP()) SysReg = AArch64SysReg::TPIDR_EL3; else if (MF->getSubtarget().useEL2ForTP()) SysReg = AArch64SysReg::TPIDR_EL2; else if (MF->getSubtarget().useEL1ForTP()) SysReg = AArch64SysReg::TPIDR_EL1; BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::MRS), DstReg) .addImm(SysReg); MI.eraseFromParent(); return true; } case AArch64::MOVi32imm: return expandMOVImm(MBB, MBBI, 32); case AArch64::MOVi64imm: return expandMOVImm(MBB, MBBI, 64); case AArch64::RET_ReallyLR: { // Hiding the LR use with RET_ReallyLR may lead to extra kills in the // function and missing live-ins. We are fine in practice because callee // saved register handling ensures the register value is restored before // RET, but we need the undef flag here to appease the MachineVerifier // liveness checks. MachineInstrBuilder MIB = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::RET)) .addReg(AArch64::LR, RegState::Undef); transferImpOps(MI, MIB, MIB); MI.eraseFromParent(); return true; } case AArch64::CMP_SWAP_8: return expandCMP_SWAP(MBB, MBBI, AArch64::LDAXRB, AArch64::STLXRB, AArch64::SUBSWrx, AArch64_AM::getArithExtendImm(AArch64_AM::UXTB, 0), AArch64::WZR, NextMBBI); case AArch64::CMP_SWAP_16: return expandCMP_SWAP(MBB, MBBI, AArch64::LDAXRH, AArch64::STLXRH, AArch64::SUBSWrx, AArch64_AM::getArithExtendImm(AArch64_AM::UXTH, 0), AArch64::WZR, NextMBBI); case AArch64::CMP_SWAP_32: return expandCMP_SWAP(MBB, MBBI, AArch64::LDAXRW, AArch64::STLXRW, AArch64::SUBSWrs, AArch64_AM::getShifterImm(AArch64_AM::LSL, 0), AArch64::WZR, NextMBBI); case AArch64::CMP_SWAP_64: return expandCMP_SWAP(MBB, MBBI, AArch64::LDAXRX, AArch64::STLXRX, AArch64::SUBSXrs, AArch64_AM::getShifterImm(AArch64_AM::LSL, 0), AArch64::XZR, NextMBBI); case AArch64::CMP_SWAP_128: return expandCMP_SWAP_128(MBB, MBBI, NextMBBI); case AArch64::AESMCrrTied: case AArch64::AESIMCrrTied: { MachineInstrBuilder MIB = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Opcode == AArch64::AESMCrrTied ? AArch64::AESMCrr : AArch64::AESIMCrr)) .add(MI.getOperand(0)) .add(MI.getOperand(1)); transferImpOps(MI, MIB, MIB); MI.eraseFromParent(); return true; } case AArch64::IRGstack: { MachineFunction &MF = *MBB.getParent(); const AArch64FunctionInfo *AFI = MF.getInfo(); const AArch64FrameLowering *TFI = MF.getSubtarget().getFrameLowering(); // IRG does not allow immediate offset. getTaggedBasePointerOffset should // almost always point to SP-after-prologue; if not, emit a longer // instruction sequence. int BaseOffset = -AFI->getTaggedBasePointerOffset(); Register FrameReg; StackOffset FrameRegOffset = TFI->resolveFrameOffsetReference( MF, BaseOffset, false /*isFixed*/, false /*isSVE*/, FrameReg, /*PreferFP=*/false, /*ForSimm=*/true); Register SrcReg = FrameReg; if (FrameRegOffset) { // Use output register as temporary. SrcReg = MI.getOperand(0).getReg(); emitFrameOffset(MBB, &MI, MI.getDebugLoc(), SrcReg, FrameReg, FrameRegOffset, TII); } BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::IRG)) .add(MI.getOperand(0)) .addUse(SrcReg) .add(MI.getOperand(2)); MI.eraseFromParent(); return true; } case AArch64::TAGPstack: { int64_t Offset = MI.getOperand(2).getImm(); BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(Offset >= 0 ? AArch64::ADDG : AArch64::SUBG)) .add(MI.getOperand(0)) .add(MI.getOperand(1)) .addImm(std::abs(Offset)) .add(MI.getOperand(4)); MI.eraseFromParent(); return true; } case AArch64::STGloop_wback: case AArch64::STZGloop_wback: return expandSetTagLoop(MBB, MBBI, NextMBBI); case AArch64::STGloop: case AArch64::STZGloop: report_fatal_error( "Non-writeback variants of STGloop / STZGloop should not " "survive past PrologEpilogInserter."); case AArch64::STR_ZZZZXI: return expandSVESpillFill(MBB, MBBI, AArch64::STR_ZXI, 4); case AArch64::STR_ZZZXI: return expandSVESpillFill(MBB, MBBI, AArch64::STR_ZXI, 3); case AArch64::STR_ZZXI: return expandSVESpillFill(MBB, MBBI, AArch64::STR_ZXI, 2); case AArch64::LDR_ZZZZXI: return expandSVESpillFill(MBB, MBBI, AArch64::LDR_ZXI, 4); case AArch64::LDR_ZZZXI: return expandSVESpillFill(MBB, MBBI, AArch64::LDR_ZXI, 3); case AArch64::LDR_ZZXI: return expandSVESpillFill(MBB, MBBI, AArch64::LDR_ZXI, 2); } return false; } /// Iterate over the instructions in basic block MBB and expand any /// pseudo instructions. Return true if anything was modified. bool AArch64ExpandPseudo::expandMBB(MachineBasicBlock &MBB) { bool Modified = false; MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end(); while (MBBI != E) { MachineBasicBlock::iterator NMBBI = std::next(MBBI); Modified |= expandMI(MBB, MBBI, NMBBI); MBBI = NMBBI; } return Modified; } bool AArch64ExpandPseudo::runOnMachineFunction(MachineFunction &MF) { TII = static_cast(MF.getSubtarget().getInstrInfo()); bool Modified = false; for (auto &MBB : MF) Modified |= expandMBB(MBB); return Modified; } /// Returns an instance of the pseudo instruction expansion pass. FunctionPass *llvm::createAArch64ExpandPseudoPass() { return new AArch64ExpandPseudo(); }