| //===- llvm/CodeGen/GlobalISel/Utils.cpp -------------------------*- C++ -*-==// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| /// \file This file implements the utility functions used by the GlobalISel |
| /// pipeline. |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/CodeGen/GlobalISel/Utils.h" |
| #include "llvm/ADT/APFloat.h" |
| #include "llvm/ADT/APInt.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h" |
| #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h" |
| #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h" |
| #include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/CodeGen/StackProtector.h" |
| #include "llvm/CodeGen/TargetInstrInfo.h" |
| #include "llvm/CodeGen/TargetLowering.h" |
| #include "llvm/CodeGen/TargetPassConfig.h" |
| #include "llvm/CodeGen/TargetRegisterInfo.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/Target/TargetMachine.h" |
| |
| #define DEBUG_TYPE "globalisel-utils" |
| |
| using namespace llvm; |
| using namespace MIPatternMatch; |
| |
| Register llvm::constrainRegToClass(MachineRegisterInfo &MRI, |
| const TargetInstrInfo &TII, |
| const RegisterBankInfo &RBI, Register Reg, |
| const TargetRegisterClass &RegClass) { |
| if (!RBI.constrainGenericRegister(Reg, RegClass, MRI)) |
| return MRI.createVirtualRegister(&RegClass); |
| |
| return Reg; |
| } |
| |
| Register llvm::constrainOperandRegClass( |
| const MachineFunction &MF, const TargetRegisterInfo &TRI, |
| MachineRegisterInfo &MRI, const TargetInstrInfo &TII, |
| const RegisterBankInfo &RBI, MachineInstr &InsertPt, |
| const TargetRegisterClass &RegClass, MachineOperand &RegMO) { |
| Register Reg = RegMO.getReg(); |
| // Assume physical registers are properly constrained. |
| assert(Register::isVirtualRegister(Reg) && "PhysReg not implemented"); |
| |
| Register ConstrainedReg = constrainRegToClass(MRI, TII, RBI, Reg, RegClass); |
| // If we created a new virtual register because the class is not compatible |
| // then create a copy between the new and the old register. |
| if (ConstrainedReg != Reg) { |
| MachineBasicBlock::iterator InsertIt(&InsertPt); |
| MachineBasicBlock &MBB = *InsertPt.getParent(); |
| if (RegMO.isUse()) { |
| BuildMI(MBB, InsertIt, InsertPt.getDebugLoc(), |
| TII.get(TargetOpcode::COPY), ConstrainedReg) |
| .addReg(Reg); |
| } else { |
| assert(RegMO.isDef() && "Must be a definition"); |
| BuildMI(MBB, std::next(InsertIt), InsertPt.getDebugLoc(), |
| TII.get(TargetOpcode::COPY), Reg) |
| .addReg(ConstrainedReg); |
| } |
| if (GISelChangeObserver *Observer = MF.getObserver()) { |
| Observer->changingInstr(*RegMO.getParent()); |
| } |
| RegMO.setReg(ConstrainedReg); |
| if (GISelChangeObserver *Observer = MF.getObserver()) { |
| Observer->changedInstr(*RegMO.getParent()); |
| } |
| } else { |
| if (GISelChangeObserver *Observer = MF.getObserver()) { |
| if (!RegMO.isDef()) { |
| MachineInstr *RegDef = MRI.getVRegDef(Reg); |
| Observer->changedInstr(*RegDef); |
| } |
| Observer->changingAllUsesOfReg(MRI, Reg); |
| Observer->finishedChangingAllUsesOfReg(); |
| } |
| } |
| return ConstrainedReg; |
| } |
| |
| Register llvm::constrainOperandRegClass( |
| const MachineFunction &MF, const TargetRegisterInfo &TRI, |
| MachineRegisterInfo &MRI, const TargetInstrInfo &TII, |
| const RegisterBankInfo &RBI, MachineInstr &InsertPt, const MCInstrDesc &II, |
| MachineOperand &RegMO, unsigned OpIdx) { |
| Register Reg = RegMO.getReg(); |
| // Assume physical registers are properly constrained. |
| assert(Register::isVirtualRegister(Reg) && "PhysReg not implemented"); |
| |
| const TargetRegisterClass *RegClass = TII.getRegClass(II, OpIdx, &TRI, MF); |
| // Some of the target independent instructions, like COPY, may not impose any |
| // register class constraints on some of their operands: If it's a use, we can |
| // skip constraining as the instruction defining the register would constrain |
| // it. |
| |
| // We can't constrain unallocatable register classes, because we can't create |
| // virtual registers for these classes, so we need to let targets handled this |
| // case. |
| if (RegClass && !RegClass->isAllocatable()) |
| RegClass = TRI.getConstrainedRegClassForOperand(RegMO, MRI); |
| |
| if (!RegClass) { |
| assert((!isTargetSpecificOpcode(II.getOpcode()) || RegMO.isUse()) && |
| "Register class constraint is required unless either the " |
| "instruction is target independent or the operand is a use"); |
| // FIXME: Just bailing out like this here could be not enough, unless we |
| // expect the users of this function to do the right thing for PHIs and |
| // COPY: |
| // v1 = COPY v0 |
| // v2 = COPY v1 |
| // v1 here may end up not being constrained at all. Please notice that to |
| // reproduce the issue we likely need a destination pattern of a selection |
| // rule producing such extra copies, not just an input GMIR with them as |
| // every existing target using selectImpl handles copies before calling it |
| // and they never reach this function. |
| return Reg; |
| } |
| return constrainOperandRegClass(MF, TRI, MRI, TII, RBI, InsertPt, *RegClass, |
| RegMO); |
| } |
| |
| bool llvm::constrainSelectedInstRegOperands(MachineInstr &I, |
| const TargetInstrInfo &TII, |
| const TargetRegisterInfo &TRI, |
| const RegisterBankInfo &RBI) { |
| assert(!isPreISelGenericOpcode(I.getOpcode()) && |
| "A selected instruction is expected"); |
| MachineBasicBlock &MBB = *I.getParent(); |
| MachineFunction &MF = *MBB.getParent(); |
| MachineRegisterInfo &MRI = MF.getRegInfo(); |
| |
| for (unsigned OpI = 0, OpE = I.getNumExplicitOperands(); OpI != OpE; ++OpI) { |
| MachineOperand &MO = I.getOperand(OpI); |
| |
| // There's nothing to be done on non-register operands. |
| if (!MO.isReg()) |
| continue; |
| |
| LLVM_DEBUG(dbgs() << "Converting operand: " << MO << '\n'); |
| assert(MO.isReg() && "Unsupported non-reg operand"); |
| |
| Register Reg = MO.getReg(); |
| // Physical registers don't need to be constrained. |
| if (Register::isPhysicalRegister(Reg)) |
| continue; |
| |
| // Register operands with a value of 0 (e.g. predicate operands) don't need |
| // to be constrained. |
| if (Reg == 0) |
| continue; |
| |
| // If the operand is a vreg, we should constrain its regclass, and only |
| // insert COPYs if that's impossible. |
| // constrainOperandRegClass does that for us. |
| constrainOperandRegClass(MF, TRI, MRI, TII, RBI, I, I.getDesc(), MO, OpI); |
| |
| // Tie uses to defs as indicated in MCInstrDesc if this hasn't already been |
| // done. |
| if (MO.isUse()) { |
| int DefIdx = I.getDesc().getOperandConstraint(OpI, MCOI::TIED_TO); |
| if (DefIdx != -1 && !I.isRegTiedToUseOperand(DefIdx)) |
| I.tieOperands(DefIdx, OpI); |
| } |
| } |
| return true; |
| } |
| |
| bool llvm::canReplaceReg(Register DstReg, Register SrcReg, |
| MachineRegisterInfo &MRI) { |
| // Give up if either DstReg or SrcReg is a physical register. |
| if (DstReg.isPhysical() || SrcReg.isPhysical()) |
| return false; |
| // Give up if the types don't match. |
| if (MRI.getType(DstReg) != MRI.getType(SrcReg)) |
| return false; |
| // Replace if either DstReg has no constraints or the register |
| // constraints match. |
| return !MRI.getRegClassOrRegBank(DstReg) || |
| MRI.getRegClassOrRegBank(DstReg) == MRI.getRegClassOrRegBank(SrcReg); |
| } |
| |
| bool llvm::isTriviallyDead(const MachineInstr &MI, |
| const MachineRegisterInfo &MRI) { |
| // FIXME: This logical is mostly duplicated with |
| // DeadMachineInstructionElim::isDead. Why is LOCAL_ESCAPE not considered in |
| // MachineInstr::isLabel? |
| |
| // Don't delete frame allocation labels. |
| if (MI.getOpcode() == TargetOpcode::LOCAL_ESCAPE) |
| return false; |
| |
| // If we can move an instruction, we can remove it. Otherwise, it has |
| // a side-effect of some sort. |
| bool SawStore = false; |
| if (!MI.isSafeToMove(/*AA=*/nullptr, SawStore) && !MI.isPHI()) |
| return false; |
| |
| // Instructions without side-effects are dead iff they only define dead vregs. |
| for (auto &MO : MI.operands()) { |
| if (!MO.isReg() || !MO.isDef()) |
| continue; |
| |
| Register Reg = MO.getReg(); |
| if (Register::isPhysicalRegister(Reg) || !MRI.use_nodbg_empty(Reg)) |
| return false; |
| } |
| return true; |
| } |
| |
| static void reportGISelDiagnostic(DiagnosticSeverity Severity, |
| MachineFunction &MF, |
| const TargetPassConfig &TPC, |
| MachineOptimizationRemarkEmitter &MORE, |
| MachineOptimizationRemarkMissed &R) { |
| bool IsFatal = Severity == DS_Error && |
| TPC.isGlobalISelAbortEnabled(); |
| // Print the function name explicitly if we don't have a debug location (which |
| // makes the diagnostic less useful) or if we're going to emit a raw error. |
| if (!R.getLocation().isValid() || IsFatal) |
| R << (" (in function: " + MF.getName() + ")").str(); |
| |
| if (IsFatal) |
| report_fatal_error(R.getMsg()); |
| else |
| MORE.emit(R); |
| } |
| |
| void llvm::reportGISelWarning(MachineFunction &MF, const TargetPassConfig &TPC, |
| MachineOptimizationRemarkEmitter &MORE, |
| MachineOptimizationRemarkMissed &R) { |
| reportGISelDiagnostic(DS_Warning, MF, TPC, MORE, R); |
| } |
| |
| void llvm::reportGISelFailure(MachineFunction &MF, const TargetPassConfig &TPC, |
| MachineOptimizationRemarkEmitter &MORE, |
| MachineOptimizationRemarkMissed &R) { |
| MF.getProperties().set(MachineFunctionProperties::Property::FailedISel); |
| reportGISelDiagnostic(DS_Error, MF, TPC, MORE, R); |
| } |
| |
| void llvm::reportGISelFailure(MachineFunction &MF, const TargetPassConfig &TPC, |
| MachineOptimizationRemarkEmitter &MORE, |
| const char *PassName, StringRef Msg, |
| const MachineInstr &MI) { |
| MachineOptimizationRemarkMissed R(PassName, "GISelFailure: ", |
| MI.getDebugLoc(), MI.getParent()); |
| R << Msg; |
| // Printing MI is expensive; only do it if expensive remarks are enabled. |
| if (TPC.isGlobalISelAbortEnabled() || MORE.allowExtraAnalysis(PassName)) |
| R << ": " << ore::MNV("Inst", MI); |
| reportGISelFailure(MF, TPC, MORE, R); |
| } |
| |
| Optional<APInt> llvm::getConstantVRegVal(Register VReg, |
| const MachineRegisterInfo &MRI) { |
| Optional<ValueAndVReg> ValAndVReg = |
| getConstantVRegValWithLookThrough(VReg, MRI, /*LookThroughInstrs*/ false); |
| assert((!ValAndVReg || ValAndVReg->VReg == VReg) && |
| "Value found while looking through instrs"); |
| if (!ValAndVReg) |
| return None; |
| return ValAndVReg->Value; |
| } |
| |
| Optional<int64_t> llvm::getConstantVRegSExtVal(Register VReg, |
| const MachineRegisterInfo &MRI) { |
| Optional<APInt> Val = getConstantVRegVal(VReg, MRI); |
| if (Val && Val->getBitWidth() <= 64) |
| return Val->getSExtValue(); |
| return None; |
| } |
| |
| Optional<ValueAndVReg> llvm::getConstantVRegValWithLookThrough( |
| Register VReg, const MachineRegisterInfo &MRI, bool LookThroughInstrs, |
| bool HandleFConstant, bool LookThroughAnyExt) { |
| SmallVector<std::pair<unsigned, unsigned>, 4> SeenOpcodes; |
| MachineInstr *MI; |
| auto IsConstantOpcode = [HandleFConstant](unsigned Opcode) { |
| return Opcode == TargetOpcode::G_CONSTANT || |
| (HandleFConstant && Opcode == TargetOpcode::G_FCONSTANT); |
| }; |
| auto GetImmediateValue = [HandleFConstant, |
| &MRI](const MachineInstr &MI) -> Optional<APInt> { |
| const MachineOperand &CstVal = MI.getOperand(1); |
| if (!CstVal.isImm() && !CstVal.isCImm() && |
| (!HandleFConstant || !CstVal.isFPImm())) |
| return None; |
| if (!CstVal.isFPImm()) { |
| unsigned BitWidth = |
| MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(); |
| APInt Val = CstVal.isImm() ? APInt(BitWidth, CstVal.getImm()) |
| : CstVal.getCImm()->getValue(); |
| assert(Val.getBitWidth() == BitWidth && |
| "Value bitwidth doesn't match definition type"); |
| return Val; |
| } |
| return CstVal.getFPImm()->getValueAPF().bitcastToAPInt(); |
| }; |
| while ((MI = MRI.getVRegDef(VReg)) && !IsConstantOpcode(MI->getOpcode()) && |
| LookThroughInstrs) { |
| switch (MI->getOpcode()) { |
| case TargetOpcode::G_ANYEXT: |
| if (!LookThroughAnyExt) |
| return None; |
| LLVM_FALLTHROUGH; |
| case TargetOpcode::G_TRUNC: |
| case TargetOpcode::G_SEXT: |
| case TargetOpcode::G_ZEXT: |
| SeenOpcodes.push_back(std::make_pair( |
| MI->getOpcode(), |
| MRI.getType(MI->getOperand(0).getReg()).getSizeInBits())); |
| VReg = MI->getOperand(1).getReg(); |
| break; |
| case TargetOpcode::COPY: |
| VReg = MI->getOperand(1).getReg(); |
| if (Register::isPhysicalRegister(VReg)) |
| return None; |
| break; |
| case TargetOpcode::G_INTTOPTR: |
| VReg = MI->getOperand(1).getReg(); |
| break; |
| default: |
| return None; |
| } |
| } |
| if (!MI || !IsConstantOpcode(MI->getOpcode())) |
| return None; |
| |
| Optional<APInt> MaybeVal = GetImmediateValue(*MI); |
| if (!MaybeVal) |
| return None; |
| APInt &Val = *MaybeVal; |
| while (!SeenOpcodes.empty()) { |
| std::pair<unsigned, unsigned> OpcodeAndSize = SeenOpcodes.pop_back_val(); |
| switch (OpcodeAndSize.first) { |
| case TargetOpcode::G_TRUNC: |
| Val = Val.trunc(OpcodeAndSize.second); |
| break; |
| case TargetOpcode::G_ANYEXT: |
| case TargetOpcode::G_SEXT: |
| Val = Val.sext(OpcodeAndSize.second); |
| break; |
| case TargetOpcode::G_ZEXT: |
| Val = Val.zext(OpcodeAndSize.second); |
| break; |
| } |
| } |
| |
| return ValueAndVReg{Val, VReg}; |
| } |
| |
| const ConstantFP * |
| llvm::getConstantFPVRegVal(Register VReg, const MachineRegisterInfo &MRI) { |
| MachineInstr *MI = MRI.getVRegDef(VReg); |
| if (TargetOpcode::G_FCONSTANT != MI->getOpcode()) |
| return nullptr; |
| return MI->getOperand(1).getFPImm(); |
| } |
| |
| Optional<DefinitionAndSourceRegister> |
| llvm::getDefSrcRegIgnoringCopies(Register Reg, const MachineRegisterInfo &MRI) { |
| Register DefSrcReg = Reg; |
| auto *DefMI = MRI.getVRegDef(Reg); |
| auto DstTy = MRI.getType(DefMI->getOperand(0).getReg()); |
| if (!DstTy.isValid()) |
| return None; |
| while (DefMI->getOpcode() == TargetOpcode::COPY) { |
| Register SrcReg = DefMI->getOperand(1).getReg(); |
| auto SrcTy = MRI.getType(SrcReg); |
| if (!SrcTy.isValid()) |
| break; |
| DefMI = MRI.getVRegDef(SrcReg); |
| DefSrcReg = SrcReg; |
| } |
| return DefinitionAndSourceRegister{DefMI, DefSrcReg}; |
| } |
| |
| MachineInstr *llvm::getDefIgnoringCopies(Register Reg, |
| const MachineRegisterInfo &MRI) { |
| Optional<DefinitionAndSourceRegister> DefSrcReg = |
| getDefSrcRegIgnoringCopies(Reg, MRI); |
| return DefSrcReg ? DefSrcReg->MI : nullptr; |
| } |
| |
| Register llvm::getSrcRegIgnoringCopies(Register Reg, |
| const MachineRegisterInfo &MRI) { |
| Optional<DefinitionAndSourceRegister> DefSrcReg = |
| getDefSrcRegIgnoringCopies(Reg, MRI); |
| return DefSrcReg ? DefSrcReg->Reg : Register(); |
| } |
| |
| MachineInstr *llvm::getOpcodeDef(unsigned Opcode, Register Reg, |
| const MachineRegisterInfo &MRI) { |
| MachineInstr *DefMI = getDefIgnoringCopies(Reg, MRI); |
| return DefMI && DefMI->getOpcode() == Opcode ? DefMI : nullptr; |
| } |
| |
| APFloat llvm::getAPFloatFromSize(double Val, unsigned Size) { |
| if (Size == 32) |
| return APFloat(float(Val)); |
| if (Size == 64) |
| return APFloat(Val); |
| if (Size != 16) |
| llvm_unreachable("Unsupported FPConstant size"); |
| bool Ignored; |
| APFloat APF(Val); |
| APF.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &Ignored); |
| return APF; |
| } |
| |
| Optional<APInt> llvm::ConstantFoldBinOp(unsigned Opcode, const Register Op1, |
| const Register Op2, |
| const MachineRegisterInfo &MRI) { |
| auto MaybeOp2Cst = getConstantVRegVal(Op2, MRI); |
| if (!MaybeOp2Cst) |
| return None; |
| |
| auto MaybeOp1Cst = getConstantVRegVal(Op1, MRI); |
| if (!MaybeOp1Cst) |
| return None; |
| |
| const APInt &C1 = *MaybeOp1Cst; |
| const APInt &C2 = *MaybeOp2Cst; |
| switch (Opcode) { |
| default: |
| break; |
| case TargetOpcode::G_ADD: |
| return C1 + C2; |
| case TargetOpcode::G_AND: |
| return C1 & C2; |
| case TargetOpcode::G_ASHR: |
| return C1.ashr(C2); |
| case TargetOpcode::G_LSHR: |
| return C1.lshr(C2); |
| case TargetOpcode::G_MUL: |
| return C1 * C2; |
| case TargetOpcode::G_OR: |
| return C1 | C2; |
| case TargetOpcode::G_SHL: |
| return C1 << C2; |
| case TargetOpcode::G_SUB: |
| return C1 - C2; |
| case TargetOpcode::G_XOR: |
| return C1 ^ C2; |
| case TargetOpcode::G_UDIV: |
| if (!C2.getBoolValue()) |
| break; |
| return C1.udiv(C2); |
| case TargetOpcode::G_SDIV: |
| if (!C2.getBoolValue()) |
| break; |
| return C1.sdiv(C2); |
| case TargetOpcode::G_UREM: |
| if (!C2.getBoolValue()) |
| break; |
| return C1.urem(C2); |
| case TargetOpcode::G_SREM: |
| if (!C2.getBoolValue()) |
| break; |
| return C1.srem(C2); |
| } |
| |
| return None; |
| } |
| |
| bool llvm::isKnownNeverNaN(Register Val, const MachineRegisterInfo &MRI, |
| bool SNaN) { |
| const MachineInstr *DefMI = MRI.getVRegDef(Val); |
| if (!DefMI) |
| return false; |
| |
| const TargetMachine& TM = DefMI->getMF()->getTarget(); |
| if (DefMI->getFlag(MachineInstr::FmNoNans) || TM.Options.NoNaNsFPMath) |
| return true; |
| |
| if (SNaN) { |
| // FP operations quiet. For now, just handle the ones inserted during |
| // legalization. |
| switch (DefMI->getOpcode()) { |
| case TargetOpcode::G_FPEXT: |
| case TargetOpcode::G_FPTRUNC: |
| case TargetOpcode::G_FCANONICALIZE: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| return false; |
| } |
| |
| Align llvm::inferAlignFromPtrInfo(MachineFunction &MF, |
| const MachinePointerInfo &MPO) { |
| auto PSV = MPO.V.dyn_cast<const PseudoSourceValue *>(); |
| if (auto FSPV = dyn_cast_or_null<FixedStackPseudoSourceValue>(PSV)) { |
| MachineFrameInfo &MFI = MF.getFrameInfo(); |
| return commonAlignment(MFI.getObjectAlign(FSPV->getFrameIndex()), |
| MPO.Offset); |
| } |
| |
| return Align(1); |
| } |
| |
| Register llvm::getFunctionLiveInPhysReg(MachineFunction &MF, |
| const TargetInstrInfo &TII, |
| MCRegister PhysReg, |
| const TargetRegisterClass &RC, |
| LLT RegTy) { |
| DebugLoc DL; // FIXME: Is no location the right choice? |
| MachineBasicBlock &EntryMBB = MF.front(); |
| MachineRegisterInfo &MRI = MF.getRegInfo(); |
| Register LiveIn = MRI.getLiveInVirtReg(PhysReg); |
| if (LiveIn) { |
| MachineInstr *Def = MRI.getVRegDef(LiveIn); |
| if (Def) { |
| // FIXME: Should the verifier check this is in the entry block? |
| assert(Def->getParent() == &EntryMBB && "live-in copy not in entry block"); |
| return LiveIn; |
| } |
| |
| // It's possible the incoming argument register and copy was added during |
| // lowering, but later deleted due to being/becoming dead. If this happens, |
| // re-insert the copy. |
| } else { |
| // The live in register was not present, so add it. |
| LiveIn = MF.addLiveIn(PhysReg, &RC); |
| if (RegTy.isValid()) |
| MRI.setType(LiveIn, RegTy); |
| } |
| |
| BuildMI(EntryMBB, EntryMBB.begin(), DL, TII.get(TargetOpcode::COPY), LiveIn) |
| .addReg(PhysReg); |
| if (!EntryMBB.isLiveIn(PhysReg)) |
| EntryMBB.addLiveIn(PhysReg); |
| return LiveIn; |
| } |
| |
| Optional<APInt> llvm::ConstantFoldExtOp(unsigned Opcode, const Register Op1, |
| uint64_t Imm, |
| const MachineRegisterInfo &MRI) { |
| auto MaybeOp1Cst = getConstantVRegVal(Op1, MRI); |
| if (MaybeOp1Cst) { |
| switch (Opcode) { |
| default: |
| break; |
| case TargetOpcode::G_SEXT_INREG: { |
| LLT Ty = MRI.getType(Op1); |
| return MaybeOp1Cst->trunc(Imm).sext(Ty.getScalarSizeInBits()); |
| } |
| } |
| } |
| return None; |
| } |
| |
| bool llvm::isKnownToBeAPowerOfTwo(Register Reg, const MachineRegisterInfo &MRI, |
| GISelKnownBits *KB) { |
| Optional<DefinitionAndSourceRegister> DefSrcReg = |
| getDefSrcRegIgnoringCopies(Reg, MRI); |
| if (!DefSrcReg) |
| return false; |
| |
| const MachineInstr &MI = *DefSrcReg->MI; |
| const LLT Ty = MRI.getType(Reg); |
| |
| switch (MI.getOpcode()) { |
| case TargetOpcode::G_CONSTANT: { |
| unsigned BitWidth = Ty.getScalarSizeInBits(); |
| const ConstantInt *CI = MI.getOperand(1).getCImm(); |
| return CI->getValue().zextOrTrunc(BitWidth).isPowerOf2(); |
| } |
| case TargetOpcode::G_SHL: { |
| // A left-shift of a constant one will have exactly one bit set because |
| // shifting the bit off the end is undefined. |
| |
| // TODO: Constant splat |
| if (auto ConstLHS = getConstantVRegVal(MI.getOperand(1).getReg(), MRI)) { |
| if (*ConstLHS == 1) |
| return true; |
| } |
| |
| break; |
| } |
| case TargetOpcode::G_LSHR: { |
| if (auto ConstLHS = getConstantVRegVal(MI.getOperand(1).getReg(), MRI)) { |
| if (ConstLHS->isSignMask()) |
| return true; |
| } |
| |
| break; |
| } |
| default: |
| break; |
| } |
| |
| // TODO: Are all operands of a build vector constant powers of two? |
| if (!KB) |
| return false; |
| |
| // More could be done here, though the above checks are enough |
| // to handle some common cases. |
| |
| // Fall back to computeKnownBits to catch other known cases. |
| KnownBits Known = KB->getKnownBits(Reg); |
| return (Known.countMaxPopulation() == 1) && (Known.countMinPopulation() == 1); |
| } |
| |
| void llvm::getSelectionDAGFallbackAnalysisUsage(AnalysisUsage &AU) { |
| AU.addPreserved<StackProtector>(); |
| } |
| |
| static unsigned getLCMSize(unsigned OrigSize, unsigned TargetSize) { |
| unsigned Mul = OrigSize * TargetSize; |
| unsigned GCDSize = greatestCommonDivisor(OrigSize, TargetSize); |
| return Mul / GCDSize; |
| } |
| |
| LLT llvm::getLCMType(LLT OrigTy, LLT TargetTy) { |
| const unsigned OrigSize = OrigTy.getSizeInBits(); |
| const unsigned TargetSize = TargetTy.getSizeInBits(); |
| |
| if (OrigSize == TargetSize) |
| return OrigTy; |
| |
| if (OrigTy.isVector()) { |
| const LLT OrigElt = OrigTy.getElementType(); |
| |
| if (TargetTy.isVector()) { |
| const LLT TargetElt = TargetTy.getElementType(); |
| |
| if (OrigElt.getSizeInBits() == TargetElt.getSizeInBits()) { |
| int GCDElts = greatestCommonDivisor(OrigTy.getNumElements(), |
| TargetTy.getNumElements()); |
| // Prefer the original element type. |
| int Mul = OrigTy.getNumElements() * TargetTy.getNumElements(); |
| return LLT::vector(Mul / GCDElts, OrigTy.getElementType()); |
| } |
| } else { |
| if (OrigElt.getSizeInBits() == TargetSize) |
| return OrigTy; |
| } |
| |
| unsigned LCMSize = getLCMSize(OrigSize, TargetSize); |
| return LLT::vector(LCMSize / OrigElt.getSizeInBits(), OrigElt); |
| } |
| |
| if (TargetTy.isVector()) { |
| unsigned LCMSize = getLCMSize(OrigSize, TargetSize); |
| return LLT::vector(LCMSize / OrigSize, OrigTy); |
| } |
| |
| unsigned LCMSize = getLCMSize(OrigSize, TargetSize); |
| |
| // Preserve pointer types. |
| if (LCMSize == OrigSize) |
| return OrigTy; |
| if (LCMSize == TargetSize) |
| return TargetTy; |
| |
| return LLT::scalar(LCMSize); |
| } |
| |
| LLT llvm::getGCDType(LLT OrigTy, LLT TargetTy) { |
| const unsigned OrigSize = OrigTy.getSizeInBits(); |
| const unsigned TargetSize = TargetTy.getSizeInBits(); |
| |
| if (OrigSize == TargetSize) |
| return OrigTy; |
| |
| if (OrigTy.isVector()) { |
| LLT OrigElt = OrigTy.getElementType(); |
| if (TargetTy.isVector()) { |
| LLT TargetElt = TargetTy.getElementType(); |
| if (OrigElt.getSizeInBits() == TargetElt.getSizeInBits()) { |
| int GCD = greatestCommonDivisor(OrigTy.getNumElements(), |
| TargetTy.getNumElements()); |
| return LLT::scalarOrVector(GCD, OrigElt); |
| } |
| } else { |
| // If the source is a vector of pointers, return a pointer element. |
| if (OrigElt.getSizeInBits() == TargetSize) |
| return OrigElt; |
| } |
| |
| unsigned GCD = greatestCommonDivisor(OrigSize, TargetSize); |
| if (GCD == OrigElt.getSizeInBits()) |
| return OrigElt; |
| |
| // If we can't produce the original element type, we have to use a smaller |
| // scalar. |
| if (GCD < OrigElt.getSizeInBits()) |
| return LLT::scalar(GCD); |
| return LLT::vector(GCD / OrigElt.getSizeInBits(), OrigElt); |
| } |
| |
| if (TargetTy.isVector()) { |
| // Try to preserve the original element type. |
| LLT TargetElt = TargetTy.getElementType(); |
| if (TargetElt.getSizeInBits() == OrigSize) |
| return OrigTy; |
| } |
| |
| unsigned GCD = greatestCommonDivisor(OrigSize, TargetSize); |
| return LLT::scalar(GCD); |
| } |
| |
| Optional<int> llvm::getSplatIndex(MachineInstr &MI) { |
| assert(MI.getOpcode() == TargetOpcode::G_SHUFFLE_VECTOR && |
| "Only G_SHUFFLE_VECTOR can have a splat index!"); |
| ArrayRef<int> Mask = MI.getOperand(3).getShuffleMask(); |
| auto FirstDefinedIdx = find_if(Mask, [](int Elt) { return Elt >= 0; }); |
| |
| // If all elements are undefined, this shuffle can be considered a splat. |
| // Return 0 for better potential for callers to simplify. |
| if (FirstDefinedIdx == Mask.end()) |
| return 0; |
| |
| // Make sure all remaining elements are either undef or the same |
| // as the first non-undef value. |
| int SplatValue = *FirstDefinedIdx; |
| if (any_of(make_range(std::next(FirstDefinedIdx), Mask.end()), |
| [&SplatValue](int Elt) { return Elt >= 0 && Elt != SplatValue; })) |
| return None; |
| |
| return SplatValue; |
| } |
| |
| static bool isBuildVectorOp(unsigned Opcode) { |
| return Opcode == TargetOpcode::G_BUILD_VECTOR || |
| Opcode == TargetOpcode::G_BUILD_VECTOR_TRUNC; |
| } |
| |
| // TODO: Handle mixed undef elements. |
| static bool isBuildVectorConstantSplat(const MachineInstr &MI, |
| const MachineRegisterInfo &MRI, |
| int64_t SplatValue) { |
| if (!isBuildVectorOp(MI.getOpcode())) |
| return false; |
| |
| const unsigned NumOps = MI.getNumOperands(); |
| for (unsigned I = 1; I != NumOps; ++I) { |
| Register Element = MI.getOperand(I).getReg(); |
| if (!mi_match(Element, MRI, m_SpecificICst(SplatValue))) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| Optional<int64_t> |
| llvm::getBuildVectorConstantSplat(const MachineInstr &MI, |
| const MachineRegisterInfo &MRI) { |
| if (!isBuildVectorOp(MI.getOpcode())) |
| return None; |
| |
| const unsigned NumOps = MI.getNumOperands(); |
| Optional<int64_t> Scalar; |
| for (unsigned I = 1; I != NumOps; ++I) { |
| Register Element = MI.getOperand(I).getReg(); |
| int64_t ElementValue; |
| if (!mi_match(Element, MRI, m_ICst(ElementValue))) |
| return None; |
| if (!Scalar) |
| Scalar = ElementValue; |
| else if (*Scalar != ElementValue) |
| return None; |
| } |
| |
| return Scalar; |
| } |
| |
| bool llvm::isBuildVectorAllZeros(const MachineInstr &MI, |
| const MachineRegisterInfo &MRI) { |
| return isBuildVectorConstantSplat(MI, MRI, 0); |
| } |
| |
| bool llvm::isBuildVectorAllOnes(const MachineInstr &MI, |
| const MachineRegisterInfo &MRI) { |
| return isBuildVectorConstantSplat(MI, MRI, -1); |
| } |
| |
| bool llvm::isConstTrueVal(const TargetLowering &TLI, int64_t Val, bool IsVector, |
| bool IsFP) { |
| switch (TLI.getBooleanContents(IsVector, IsFP)) { |
| case TargetLowering::UndefinedBooleanContent: |
| return Val & 0x1; |
| case TargetLowering::ZeroOrOneBooleanContent: |
| return Val == 1; |
| case TargetLowering::ZeroOrNegativeOneBooleanContent: |
| return Val == -1; |
| } |
| llvm_unreachable("Invalid boolean contents"); |
| } |
| |
| int64_t llvm::getICmpTrueVal(const TargetLowering &TLI, bool IsVector, |
| bool IsFP) { |
| switch (TLI.getBooleanContents(IsVector, IsFP)) { |
| case TargetLowering::UndefinedBooleanContent: |
| case TargetLowering::ZeroOrOneBooleanContent: |
| return 1; |
| case TargetLowering::ZeroOrNegativeOneBooleanContent: |
| return -1; |
| } |
| llvm_unreachable("Invalid boolean contents"); |
| } |