//===- lib/CodeGen/GlobalISel/LegalizerInfo.cpp - Legalizer ---------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // Implement an interface to specify and query how an illegal operation on a // given type should be expanded. // // Issues to be resolved: // + Make it fast. // + Support weird types like i3, <7 x i3>, ... // + Operations with more than one type (ICMP, CMPXCHG, intrinsics, ...) // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/GlobalISel/LegalizerInfo.h" #include "llvm/ADT/SmallBitVector.h" #include "llvm/CodeGen/MachineInstr.h" #include "llvm/CodeGen/MachineOperand.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/TargetOpcodes.h" #include "llvm/MC/MCInstrDesc.h" #include "llvm/MC/MCInstrInfo.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/LowLevelTypeImpl.h" #include "llvm/Support/MathExtras.h" #include <algorithm> #include <map> using namespace llvm; using namespace LegalizeActions; #define DEBUG_TYPE "legalizer-info" cl::opt<bool> llvm::DisableGISelLegalityCheck( "disable-gisel-legality-check", cl::desc("Don't verify that MIR is fully legal between GlobalISel passes"), cl::Hidden); raw_ostream &LegalityQuery::print(raw_ostream &OS) const { OS << Opcode << ", Tys={"; for (const auto &Type : Types) { OS << Type << ", "; } OS << "}, Opcode="; OS << Opcode << ", MMOs={"; for (const auto &MMODescr : MMODescrs) { OS << MMODescr.Size << ", "; } OS << "}"; return OS; } LegalizeActionStep LegalizeRuleSet::apply(const LegalityQuery &Query) const { LLVM_DEBUG(dbgs() << "Applying legalizer ruleset to: "; Query.print(dbgs()); dbgs() << "\n"); if (Rules.empty()) { LLVM_DEBUG(dbgs() << ".. fallback to legacy rules (no rules defined)\n"); return {LegalizeAction::UseLegacyRules, 0, LLT{}}; } for (const auto &Rule : Rules) { if (Rule.match(Query)) { LLVM_DEBUG(dbgs() << ".. match\n"); std::pair<unsigned, LLT> Mutation = Rule.determineMutation(Query); LLVM_DEBUG(dbgs() << ".. .. " << (unsigned)Rule.getAction() << ", " << Mutation.first << ", " << Mutation.second << "\n"); assert((Query.Types[Mutation.first] != Mutation.second || Rule.getAction() == Lower || Rule.getAction() == MoreElements || Rule.getAction() == FewerElements) && "Simple loop detected"); return {Rule.getAction(), Mutation.first, Mutation.second}; } else LLVM_DEBUG(dbgs() << ".. no match\n"); } LLVM_DEBUG(dbgs() << ".. unsupported\n"); return {LegalizeAction::Unsupported, 0, LLT{}}; } bool LegalizeRuleSet::verifyTypeIdxsCoverage(unsigned NumTypeIdxs) const { #ifndef NDEBUG if (Rules.empty()) { LLVM_DEBUG( dbgs() << ".. type index coverage check SKIPPED: no rules defined\n"); return true; } const int64_t FirstUncovered = TypeIdxsCovered.find_first_unset(); if (FirstUncovered < 0) { LLVM_DEBUG(dbgs() << ".. type index coverage check SKIPPED:" " user-defined predicate detected\n"); return true; } const bool AllCovered = (FirstUncovered >= NumTypeIdxs); LLVM_DEBUG(dbgs() << ".. the first uncovered type index: " << FirstUncovered << ", " << (AllCovered ? "OK" : "FAIL") << "\n"); return AllCovered; #else return true; #endif } LegalizerInfo::LegalizerInfo() : TablesInitialized(false) { // Set defaults. // FIXME: these two (G_ANYEXT and G_TRUNC?) can be legalized to the // fundamental load/store Jakob proposed. Once loads & stores are supported. setScalarAction(TargetOpcode::G_ANYEXT, 1, {{1, Legal}}); setScalarAction(TargetOpcode::G_ZEXT, 1, {{1, Legal}}); setScalarAction(TargetOpcode::G_SEXT, 1, {{1, Legal}}); setScalarAction(TargetOpcode::G_TRUNC, 0, {{1, Legal}}); setScalarAction(TargetOpcode::G_TRUNC, 1, {{1, Legal}}); setScalarAction(TargetOpcode::G_INTRINSIC, 0, {{1, Legal}}); setScalarAction(TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS, 0, {{1, Legal}}); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_IMPLICIT_DEF, 0, narrowToSmallerAndUnsupportedIfTooSmall); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_ADD, 0, widenToLargerTypesAndNarrowToLargest); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_OR, 0, widenToLargerTypesAndNarrowToLargest); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_LOAD, 0, narrowToSmallerAndUnsupportedIfTooSmall); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_STORE, 0, narrowToSmallerAndUnsupportedIfTooSmall); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_BRCOND, 0, widenToLargerTypesUnsupportedOtherwise); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_INSERT, 0, narrowToSmallerAndUnsupportedIfTooSmall); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_EXTRACT, 0, narrowToSmallerAndUnsupportedIfTooSmall); setLegalizeScalarToDifferentSizeStrategy( TargetOpcode::G_EXTRACT, 1, narrowToSmallerAndUnsupportedIfTooSmall); setScalarAction(TargetOpcode::G_FNEG, 0, {{1, Lower}}); } void LegalizerInfo::computeTables() { assert(TablesInitialized == false); for (unsigned OpcodeIdx = 0; OpcodeIdx <= LastOp - FirstOp; ++OpcodeIdx) { const unsigned Opcode = FirstOp + OpcodeIdx; for (unsigned TypeIdx = 0; TypeIdx != SpecifiedActions[OpcodeIdx].size(); ++TypeIdx) { // 0. Collect information specified through the setAction API, i.e. // for specific bit sizes. // For scalar types: SizeAndActionsVec ScalarSpecifiedActions; // For pointer types: std::map<uint16_t, SizeAndActionsVec> AddressSpace2SpecifiedActions; // For vector types: std::map<uint16_t, SizeAndActionsVec> ElemSize2SpecifiedActions; for (auto LLT2Action : SpecifiedActions[OpcodeIdx][TypeIdx]) { const LLT Type = LLT2Action.first; const LegalizeAction Action = LLT2Action.second; auto SizeAction = std::make_pair(Type.getSizeInBits(), Action); if (Type.isPointer()) AddressSpace2SpecifiedActions[Type.getAddressSpace()].push_back( SizeAction); else if (Type.isVector()) ElemSize2SpecifiedActions[Type.getElementType().getSizeInBits()] .push_back(SizeAction); else ScalarSpecifiedActions.push_back(SizeAction); } // 1. Handle scalar types { // Decide how to handle bit sizes for which no explicit specification // was given. SizeChangeStrategy S = &unsupportedForDifferentSizes; if (TypeIdx < ScalarSizeChangeStrategies[OpcodeIdx].size() && ScalarSizeChangeStrategies[OpcodeIdx][TypeIdx] != nullptr) S = ScalarSizeChangeStrategies[OpcodeIdx][TypeIdx]; llvm::sort(ScalarSpecifiedActions.begin(), ScalarSpecifiedActions.end()); checkPartialSizeAndActionsVector(ScalarSpecifiedActions); setScalarAction(Opcode, TypeIdx, S(ScalarSpecifiedActions)); } // 2. Handle pointer types for (auto PointerSpecifiedActions : AddressSpace2SpecifiedActions) { llvm::sort(PointerSpecifiedActions.second.begin(), PointerSpecifiedActions.second.end()); checkPartialSizeAndActionsVector(PointerSpecifiedActions.second); // For pointer types, we assume that there isn't a meaningfull way // to change the number of bits used in the pointer. setPointerAction( Opcode, TypeIdx, PointerSpecifiedActions.first, unsupportedForDifferentSizes(PointerSpecifiedActions.second)); } // 3. Handle vector types SizeAndActionsVec ElementSizesSeen; for (auto VectorSpecifiedActions : ElemSize2SpecifiedActions) { llvm::sort(VectorSpecifiedActions.second.begin(), VectorSpecifiedActions.second.end()); const uint16_t ElementSize = VectorSpecifiedActions.first; ElementSizesSeen.push_back({ElementSize, Legal}); checkPartialSizeAndActionsVector(VectorSpecifiedActions.second); // For vector types, we assume that the best way to adapt the number // of elements is to the next larger number of elements type for which // the vector type is legal, unless there is no such type. In that case, // legalize towards a vector type with a smaller number of elements. SizeAndActionsVec NumElementsActions; for (SizeAndAction BitsizeAndAction : VectorSpecifiedActions.second) { assert(BitsizeAndAction.first % ElementSize == 0); const uint16_t NumElements = BitsizeAndAction.first / ElementSize; NumElementsActions.push_back({NumElements, BitsizeAndAction.second}); } setVectorNumElementAction( Opcode, TypeIdx, ElementSize, moreToWiderTypesAndLessToWidest(NumElementsActions)); } llvm::sort(ElementSizesSeen.begin(), ElementSizesSeen.end()); SizeChangeStrategy VectorElementSizeChangeStrategy = &unsupportedForDifferentSizes; if (TypeIdx < VectorElementSizeChangeStrategies[OpcodeIdx].size() && VectorElementSizeChangeStrategies[OpcodeIdx][TypeIdx] != nullptr) VectorElementSizeChangeStrategy = VectorElementSizeChangeStrategies[OpcodeIdx][TypeIdx]; setScalarInVectorAction( Opcode, TypeIdx, VectorElementSizeChangeStrategy(ElementSizesSeen)); } } TablesInitialized = true; } // FIXME: inefficient implementation for now. Without ComputeValueVTs we're // probably going to need specialized lookup structures for various types before // we have any hope of doing well with something like <13 x i3>. Even the common // cases should do better than what we have now. std::pair<LegalizeAction, LLT> LegalizerInfo::getAspectAction(const InstrAspect &Aspect) const { assert(TablesInitialized && "backend forgot to call computeTables"); // These *have* to be implemented for now, they're the fundamental basis of // how everything else is transformed. if (Aspect.Type.isScalar() || Aspect.Type.isPointer()) return findScalarLegalAction(Aspect); assert(Aspect.Type.isVector()); return findVectorLegalAction(Aspect); } /// Helper function to get LLT for the given type index. static LLT getTypeFromTypeIdx(const MachineInstr &MI, const MachineRegisterInfo &MRI, unsigned OpIdx, unsigned TypeIdx) { assert(TypeIdx < MI.getNumOperands() && "Unexpected TypeIdx"); // G_UNMERGE_VALUES has variable number of operands, but there is only // one source type and one destination type as all destinations must be the // same type. So, get the last operand if TypeIdx == 1. if (MI.getOpcode() == TargetOpcode::G_UNMERGE_VALUES && TypeIdx == 1) return MRI.getType(MI.getOperand(MI.getNumOperands() - 1).getReg()); return MRI.getType(MI.getOperand(OpIdx).getReg()); } unsigned LegalizerInfo::getOpcodeIdxForOpcode(unsigned Opcode) const { assert(Opcode >= FirstOp && Opcode <= LastOp && "Unsupported opcode"); return Opcode - FirstOp; } unsigned LegalizerInfo::getActionDefinitionsIdx(unsigned Opcode) const { unsigned OpcodeIdx = getOpcodeIdxForOpcode(Opcode); if (unsigned Alias = RulesForOpcode[OpcodeIdx].getAlias()) { LLVM_DEBUG(dbgs() << ".. opcode " << Opcode << " is aliased to " << Alias << "\n"); OpcodeIdx = getOpcodeIdxForOpcode(Alias); LLVM_DEBUG(dbgs() << ".. opcode " << Alias << " is aliased to " << RulesForOpcode[OpcodeIdx].getAlias() << "\n"); assert(RulesForOpcode[OpcodeIdx].getAlias() == 0 && "Cannot chain aliases"); } return OpcodeIdx; } const LegalizeRuleSet & LegalizerInfo::getActionDefinitions(unsigned Opcode) const { unsigned OpcodeIdx = getActionDefinitionsIdx(Opcode); return RulesForOpcode[OpcodeIdx]; } LegalizeRuleSet &LegalizerInfo::getActionDefinitionsBuilder(unsigned Opcode) { unsigned OpcodeIdx = getActionDefinitionsIdx(Opcode); auto &Result = RulesForOpcode[OpcodeIdx]; assert(!Result.isAliasedByAnother() && "Modifying this opcode will modify aliases"); return Result; } LegalizeRuleSet &LegalizerInfo::getActionDefinitionsBuilder( std::initializer_list<unsigned> Opcodes) { unsigned Representative = *Opcodes.begin(); assert(Opcodes.begin() != Opcodes.end() && Opcodes.begin() + 1 != Opcodes.end() && "Initializer list must have at least two opcodes"); for (auto I = Opcodes.begin() + 1, E = Opcodes.end(); I != E; ++I) aliasActionDefinitions(Representative, *I); auto &Return = getActionDefinitionsBuilder(Representative); Return.setIsAliasedByAnother(); return Return; } void LegalizerInfo::aliasActionDefinitions(unsigned OpcodeTo, unsigned OpcodeFrom) { assert(OpcodeTo != OpcodeFrom && "Cannot alias to self"); assert(OpcodeTo >= FirstOp && OpcodeTo <= LastOp && "Unsupported opcode"); const unsigned OpcodeFromIdx = getOpcodeIdxForOpcode(OpcodeFrom); RulesForOpcode[OpcodeFromIdx].aliasTo(OpcodeTo); } LegalizeActionStep LegalizerInfo::getAction(const LegalityQuery &Query) const { LegalizeActionStep Step = getActionDefinitions(Query.Opcode).apply(Query); if (Step.Action != LegalizeAction::UseLegacyRules) { return Step; } for (unsigned i = 0; i < Query.Types.size(); ++i) { auto Action = getAspectAction({Query.Opcode, i, Query.Types[i]}); if (Action.first != Legal) { LLVM_DEBUG(dbgs() << ".. (legacy) Type " << i << " Action=" << (unsigned)Action.first << ", " << Action.second << "\n"); return {Action.first, i, Action.second}; } else LLVM_DEBUG(dbgs() << ".. (legacy) Type " << i << " Legal\n"); } LLVM_DEBUG(dbgs() << ".. (legacy) Legal\n"); return {Legal, 0, LLT{}}; } LegalizeActionStep LegalizerInfo::getAction(const MachineInstr &MI, const MachineRegisterInfo &MRI) const { SmallVector<LLT, 2> Types; SmallBitVector SeenTypes(8); const MCOperandInfo *OpInfo = MI.getDesc().OpInfo; // FIXME: probably we'll need to cache the results here somehow? for (unsigned i = 0; i < MI.getDesc().getNumOperands(); ++i) { if (!OpInfo[i].isGenericType()) continue; // We must only record actions once for each TypeIdx; otherwise we'd // try to legalize operands multiple times down the line. unsigned TypeIdx = OpInfo[i].getGenericTypeIndex(); if (SeenTypes[TypeIdx]) continue; SeenTypes.set(TypeIdx); LLT Ty = getTypeFromTypeIdx(MI, MRI, i, TypeIdx); Types.push_back(Ty); } SmallVector<LegalityQuery::MemDesc, 2> MemDescrs; for (const auto &MMO : MI.memoperands()) MemDescrs.push_back( {MMO->getSize() /* in bytes */ * 8, MMO->getOrdering()}); return getAction({MI.getOpcode(), Types, MemDescrs}); } bool LegalizerInfo::isLegal(const MachineInstr &MI, const MachineRegisterInfo &MRI) const { return getAction(MI, MRI).Action == Legal; } bool LegalizerInfo::legalizeCustom(MachineInstr &MI, MachineRegisterInfo &MRI, MachineIRBuilder &MIRBuilder) const { return false; } LegalizerInfo::SizeAndActionsVec LegalizerInfo::increaseToLargerTypesAndDecreaseToLargest( const SizeAndActionsVec &v, LegalizeAction IncreaseAction, LegalizeAction DecreaseAction) { SizeAndActionsVec result; unsigned LargestSizeSoFar = 0; if (v.size() >= 1 && v[0].first != 1) result.push_back({1, IncreaseAction}); for (size_t i = 0; i < v.size(); ++i) { result.push_back(v[i]); LargestSizeSoFar = v[i].first; if (i + 1 < v.size() && v[i + 1].first != v[i].first + 1) { result.push_back({LargestSizeSoFar + 1, IncreaseAction}); LargestSizeSoFar = v[i].first + 1; } } result.push_back({LargestSizeSoFar + 1, DecreaseAction}); return result; } LegalizerInfo::SizeAndActionsVec LegalizerInfo::decreaseToSmallerTypesAndIncreaseToSmallest( const SizeAndActionsVec &v, LegalizeAction DecreaseAction, LegalizeAction IncreaseAction) { SizeAndActionsVec result; if (v.size() == 0 || v[0].first != 1) result.push_back({1, IncreaseAction}); for (size_t i = 0; i < v.size(); ++i) { result.push_back(v[i]); if (i + 1 == v.size() || v[i + 1].first != v[i].first + 1) { result.push_back({v[i].first + 1, DecreaseAction}); } } return result; } LegalizerInfo::SizeAndAction LegalizerInfo::findAction(const SizeAndActionsVec &Vec, const uint32_t Size) { assert(Size >= 1); // Find the last element in Vec that has a bitsize equal to or smaller than // the requested bit size. // That is the element just before the first element that is bigger than Size. auto VecIt = std::upper_bound( Vec.begin(), Vec.end(), Size, [](const uint32_t Size, const SizeAndAction lhs) -> bool { return Size < lhs.first; }); assert(VecIt != Vec.begin() && "Does Vec not start with size 1?"); --VecIt; int VecIdx = VecIt - Vec.begin(); LegalizeAction Action = Vec[VecIdx].second; switch (Action) { case Legal: case Lower: case Libcall: case Custom: return {Size, Action}; case FewerElements: // FIXME: is this special case still needed and correct? // Special case for scalarization: if (Vec == SizeAndActionsVec({{1, FewerElements}})) return {1, FewerElements}; LLVM_FALLTHROUGH; case NarrowScalar: { // The following needs to be a loop, as for now, we do allow needing to // go over "Unsupported" bit sizes before finding a legalizable bit size. // e.g. (s8, WidenScalar), (s9, Unsupported), (s32, Legal). if Size==8, // we need to iterate over s9, and then to s32 to return (s32, Legal). // If we want to get rid of the below loop, we should have stronger asserts // when building the SizeAndActionsVecs, probably not allowing // "Unsupported" unless at the ends of the vector. for (int i = VecIdx - 1; i >= 0; --i) if (!needsLegalizingToDifferentSize(Vec[i].second) && Vec[i].second != Unsupported) return {Vec[i].first, Action}; llvm_unreachable(""); } case WidenScalar: case MoreElements: { // See above, the following needs to be a loop, at least for now. for (std::size_t i = VecIdx + 1; i < Vec.size(); ++i) if (!needsLegalizingToDifferentSize(Vec[i].second) && Vec[i].second != Unsupported) return {Vec[i].first, Action}; llvm_unreachable(""); } case Unsupported: return {Size, Unsupported}; case NotFound: case UseLegacyRules: llvm_unreachable("NotFound"); } llvm_unreachable("Action has an unknown enum value"); } std::pair<LegalizeAction, LLT> LegalizerInfo::findScalarLegalAction(const InstrAspect &Aspect) const { assert(Aspect.Type.isScalar() || Aspect.Type.isPointer()); if (Aspect.Opcode < FirstOp || Aspect.Opcode > LastOp) return {NotFound, LLT()}; const unsigned OpcodeIdx = getOpcodeIdxForOpcode(Aspect.Opcode); if (Aspect.Type.isPointer() && AddrSpace2PointerActions[OpcodeIdx].find(Aspect.Type.getAddressSpace()) == AddrSpace2PointerActions[OpcodeIdx].end()) { return {NotFound, LLT()}; } const SmallVector<SizeAndActionsVec, 1> &Actions = Aspect.Type.isPointer() ? AddrSpace2PointerActions[OpcodeIdx] .find(Aspect.Type.getAddressSpace()) ->second : ScalarActions[OpcodeIdx]; if (Aspect.Idx >= Actions.size()) return {NotFound, LLT()}; const SizeAndActionsVec &Vec = Actions[Aspect.Idx]; // FIXME: speed up this search, e.g. by using a results cache for repeated // queries? auto SizeAndAction = findAction(Vec, Aspect.Type.getSizeInBits()); return {SizeAndAction.second, Aspect.Type.isScalar() ? LLT::scalar(SizeAndAction.first) : LLT::pointer(Aspect.Type.getAddressSpace(), SizeAndAction.first)}; } std::pair<LegalizeAction, LLT> LegalizerInfo::findVectorLegalAction(const InstrAspect &Aspect) const { assert(Aspect.Type.isVector()); // First legalize the vector element size, then legalize the number of // lanes in the vector. if (Aspect.Opcode < FirstOp || Aspect.Opcode > LastOp) return {NotFound, Aspect.Type}; const unsigned OpcodeIdx = getOpcodeIdxForOpcode(Aspect.Opcode); const unsigned TypeIdx = Aspect.Idx; if (TypeIdx >= ScalarInVectorActions[OpcodeIdx].size()) return {NotFound, Aspect.Type}; const SizeAndActionsVec &ElemSizeVec = ScalarInVectorActions[OpcodeIdx][TypeIdx]; LLT IntermediateType; auto ElementSizeAndAction = findAction(ElemSizeVec, Aspect.Type.getScalarSizeInBits()); IntermediateType = LLT::vector(Aspect.Type.getNumElements(), ElementSizeAndAction.first); if (ElementSizeAndAction.second != Legal) return {ElementSizeAndAction.second, IntermediateType}; auto i = NumElements2Actions[OpcodeIdx].find( IntermediateType.getScalarSizeInBits()); if (i == NumElements2Actions[OpcodeIdx].end()) { return {NotFound, IntermediateType}; } const SizeAndActionsVec &NumElementsVec = (*i).second[TypeIdx]; auto NumElementsAndAction = findAction(NumElementsVec, IntermediateType.getNumElements()); return {NumElementsAndAction.second, LLT::vector(NumElementsAndAction.first, IntermediateType.getScalarSizeInBits())}; } /// \pre Type indices of every opcode form a dense set starting from 0. void LegalizerInfo::verify(const MCInstrInfo &MII) const { #ifndef NDEBUG std::vector<unsigned> FailedOpcodes; for (unsigned Opcode = FirstOp; Opcode <= LastOp; ++Opcode) { const MCInstrDesc &MCID = MII.get(Opcode); const unsigned NumTypeIdxs = std::accumulate( MCID.opInfo_begin(), MCID.opInfo_end(), 0U, [](unsigned Acc, const MCOperandInfo &OpInfo) { return OpInfo.isGenericType() ? std::max(OpInfo.getGenericTypeIndex() + 1U, Acc) : Acc; }); LLVM_DEBUG(dbgs() << MII.getName(Opcode) << " (opcode " << Opcode << "): " << NumTypeIdxs << " type ind" << (NumTypeIdxs == 1 ? "ex" : "ices") << "\n"); const LegalizeRuleSet &RuleSet = getActionDefinitions(Opcode); if (!RuleSet.verifyTypeIdxsCoverage(NumTypeIdxs)) FailedOpcodes.push_back(Opcode); } if (!FailedOpcodes.empty()) { errs() << "The following opcodes have ill-defined legalization rules:"; for (unsigned Opcode : FailedOpcodes) errs() << " " << MII.getName(Opcode); errs() << "\n"; report_fatal_error("ill-defined LegalizerInfo" ", try -debug-only=legalizer-info for details"); } #endif } #ifndef NDEBUG // FIXME: This should be in the MachineVerifier, but it can't use the // LegalizerInfo as it's currently in the separate GlobalISel library. // Note that RegBankSelected property already checked in the verifier // has the same layering problem, but we only use inline methods so // end up not needing to link against the GlobalISel library. const MachineInstr *llvm::machineFunctionIsIllegal(const MachineFunction &MF) { if (const LegalizerInfo *MLI = MF.getSubtarget().getLegalizerInfo()) { const MachineRegisterInfo &MRI = MF.getRegInfo(); for (const MachineBasicBlock &MBB : MF) for (const MachineInstr &MI : MBB) if (isPreISelGenericOpcode(MI.getOpcode()) && !MLI->isLegal(MI, MRI)) return &MI; } return nullptr; } #endif