//===- MachineFunction.cpp ------------------------------------------------===// // // 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 // //===----------------------------------------------------------------------===// // // Collect native machine code information for a function. This allows // target-specific information about the generated code to be stored with each // function. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineFunction.h" #include "llvm/ADT/BitVector.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/DenseSet.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringRef.h" #include "llvm/ADT/Twine.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/EHPersonalities.h" #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineInstr.h" #include "llvm/CodeGen/MachineJumpTableInfo.h" #include "llvm/CodeGen/MachineMemOperand.h" #include "llvm/CodeGen/MachineModuleInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/PseudoSourceValue.h" #include "llvm/CodeGen/TargetFrameLowering.h" #include "llvm/CodeGen/TargetInstrInfo.h" #include "llvm/CodeGen/TargetLowering.h" #include "llvm/CodeGen/TargetRegisterInfo.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/CodeGen/WasmEHFuncInfo.h" #include "llvm/CodeGen/WinEHFuncInfo.h" #include "llvm/Config/llvm-config.h" #include "llvm/IR/Attributes.h" #include "llvm/IR/BasicBlock.h" #include "llvm/IR/Constant.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Function.h" #include "llvm/IR/GlobalValue.h" #include "llvm/IR/Instruction.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/Metadata.h" #include "llvm/IR/Module.h" #include "llvm/IR/ModuleSlotTracker.h" #include "llvm/IR/Value.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCSymbol.h" #include "llvm/MC/SectionKind.h" #include "llvm/Support/Casting.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/DOTGraphTraits.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/GraphWriter.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetMachine.h" #include #include #include #include #include #include #include #include #include #include "LiveDebugValues/LiveDebugValues.h" using namespace llvm; #define DEBUG_TYPE "codegen" static cl::opt AlignAllFunctions( "align-all-functions", cl::desc("Force the alignment of all functions in log2 format (e.g. 4 " "means align on 16B boundaries)."), cl::init(0), cl::Hidden); static const char *getPropertyName(MachineFunctionProperties::Property Prop) { using P = MachineFunctionProperties::Property; // clang-format off switch(Prop) { case P::FailedISel: return "FailedISel"; case P::IsSSA: return "IsSSA"; case P::Legalized: return "Legalized"; case P::NoPHIs: return "NoPHIs"; case P::NoVRegs: return "NoVRegs"; case P::RegBankSelected: return "RegBankSelected"; case P::Selected: return "Selected"; case P::TracksLiveness: return "TracksLiveness"; case P::TiedOpsRewritten: return "TiedOpsRewritten"; case P::FailsVerification: return "FailsVerification"; case P::TracksDebugUserValues: return "TracksDebugUserValues"; } // clang-format on llvm_unreachable("Invalid machine function property"); } void setUnsafeStackSize(const Function &F, MachineFrameInfo &FrameInfo) { if (!F.hasFnAttribute(Attribute::SafeStack)) return; auto *Existing = dyn_cast_or_null(F.getMetadata(LLVMContext::MD_annotation)); if (!Existing || Existing->getNumOperands() != 2) return; auto *MetadataName = "unsafe-stack-size"; if (auto &N = Existing->getOperand(0)) { if (cast(N.get())->getString() == MetadataName) { if (auto &Op = Existing->getOperand(1)) { auto Val = mdconst::extract(Op)->getZExtValue(); FrameInfo.setUnsafeStackSize(Val); } } } } // Pin the vtable to this file. void MachineFunction::Delegate::anchor() {} void MachineFunctionProperties::print(raw_ostream &OS) const { const char *Separator = ""; for (BitVector::size_type I = 0; I < Properties.size(); ++I) { if (!Properties[I]) continue; OS << Separator << getPropertyName(static_cast(I)); Separator = ", "; } } //===----------------------------------------------------------------------===// // MachineFunction implementation //===----------------------------------------------------------------------===// // Out-of-line virtual method. MachineFunctionInfo::~MachineFunctionInfo() = default; void ilist_alloc_traits::deleteNode(MachineBasicBlock *MBB) { MBB->getParent()->deleteMachineBasicBlock(MBB); } static inline Align getFnStackAlignment(const TargetSubtargetInfo *STI, const Function &F) { if (auto MA = F.getFnStackAlign()) return *MA; return STI->getFrameLowering()->getStackAlign(); } MachineFunction::MachineFunction(Function &F, const LLVMTargetMachine &Target, const TargetSubtargetInfo &STI, unsigned FunctionNum, MachineModuleInfo &mmi) : F(F), Target(Target), STI(&STI), Ctx(mmi.getContext()), MMI(mmi) { FunctionNumber = FunctionNum; init(); } void MachineFunction::handleInsertion(MachineInstr &MI) { if (TheDelegate) TheDelegate->MF_HandleInsertion(MI); } void MachineFunction::handleRemoval(MachineInstr &MI) { if (TheDelegate) TheDelegate->MF_HandleRemoval(MI); } void MachineFunction::init() { // Assume the function starts in SSA form with correct liveness. Properties.set(MachineFunctionProperties::Property::IsSSA); Properties.set(MachineFunctionProperties::Property::TracksLiveness); if (STI->getRegisterInfo()) RegInfo = new (Allocator) MachineRegisterInfo(this); else RegInfo = nullptr; MFInfo = nullptr; // We can realign the stack if the target supports it and the user hasn't // explicitly asked us not to. bool CanRealignSP = STI->getFrameLowering()->isStackRealignable() && !F.hasFnAttribute("no-realign-stack"); FrameInfo = new (Allocator) MachineFrameInfo( getFnStackAlignment(STI, F), /*StackRealignable=*/CanRealignSP, /*ForcedRealign=*/CanRealignSP && F.hasFnAttribute(Attribute::StackAlignment)); setUnsafeStackSize(F, *FrameInfo); if (F.hasFnAttribute(Attribute::StackAlignment)) FrameInfo->ensureMaxAlignment(*F.getFnStackAlign()); ConstantPool = new (Allocator) MachineConstantPool(getDataLayout()); Alignment = STI->getTargetLowering()->getMinFunctionAlignment(); // FIXME: Shouldn't use pref alignment if explicit alignment is set on F. // FIXME: Use Function::hasOptSize(). if (!F.hasFnAttribute(Attribute::OptimizeForSize)) Alignment = std::max(Alignment, STI->getTargetLowering()->getPrefFunctionAlignment()); if (AlignAllFunctions) Alignment = Align(1ULL << AlignAllFunctions); JumpTableInfo = nullptr; if (isFuncletEHPersonality(classifyEHPersonality( F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) { WinEHInfo = new (Allocator) WinEHFuncInfo(); } if (isScopedEHPersonality(classifyEHPersonality( F.hasPersonalityFn() ? F.getPersonalityFn() : nullptr))) { WasmEHInfo = new (Allocator) WasmEHFuncInfo(); } assert(Target.isCompatibleDataLayout(getDataLayout()) && "Can't create a MachineFunction using a Module with a " "Target-incompatible DataLayout attached\n"); PSVManager = std::make_unique(getTarget()); } void MachineFunction::initTargetMachineFunctionInfo( const TargetSubtargetInfo &STI) { assert(!MFInfo && "MachineFunctionInfo already set"); MFInfo = Target.createMachineFunctionInfo(Allocator, F, &STI); } MachineFunction::~MachineFunction() { clear(); } void MachineFunction::clear() { Properties.reset(); // Don't call destructors on MachineInstr and MachineOperand. All of their // memory comes from the BumpPtrAllocator which is about to be purged. // // Do call MachineBasicBlock destructors, it contains std::vectors. for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I)) I->Insts.clearAndLeakNodesUnsafely(); MBBNumbering.clear(); InstructionRecycler.clear(Allocator); OperandRecycler.clear(Allocator); BasicBlockRecycler.clear(Allocator); CodeViewAnnotations.clear(); VariableDbgInfos.clear(); if (RegInfo) { RegInfo->~MachineRegisterInfo(); Allocator.Deallocate(RegInfo); } if (MFInfo) { MFInfo->~MachineFunctionInfo(); Allocator.Deallocate(MFInfo); } FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo); ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool); if (JumpTableInfo) { JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo); } if (WinEHInfo) { WinEHInfo->~WinEHFuncInfo(); Allocator.Deallocate(WinEHInfo); } if (WasmEHInfo) { WasmEHInfo->~WasmEHFuncInfo(); Allocator.Deallocate(WasmEHInfo); } } const DataLayout &MachineFunction::getDataLayout() const { return F.getParent()->getDataLayout(); } /// Get the JumpTableInfo for this function. /// If it does not already exist, allocate one. MachineJumpTableInfo *MachineFunction:: getOrCreateJumpTableInfo(unsigned EntryKind) { if (JumpTableInfo) return JumpTableInfo; JumpTableInfo = new (Allocator) MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind); return JumpTableInfo; } DenormalMode MachineFunction::getDenormalMode(const fltSemantics &FPType) const { return F.getDenormalMode(FPType); } /// Should we be emitting segmented stack stuff for the function bool MachineFunction::shouldSplitStack() const { return getFunction().hasFnAttribute("split-stack"); } [[nodiscard]] unsigned MachineFunction::addFrameInst(const MCCFIInstruction &Inst) { FrameInstructions.push_back(Inst); return FrameInstructions.size() - 1; } /// This discards all of the MachineBasicBlock numbers and recomputes them. /// This guarantees that the MBB numbers are sequential, dense, and match the /// ordering of the blocks within the function. If a specific MachineBasicBlock /// is specified, only that block and those after it are renumbered. void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { if (empty()) { MBBNumbering.clear(); return; } MachineFunction::iterator MBBI, E = end(); if (MBB == nullptr) MBBI = begin(); else MBBI = MBB->getIterator(); // Figure out the block number this should have. unsigned BlockNo = 0; if (MBBI != begin()) BlockNo = std::prev(MBBI)->getNumber() + 1; for (; MBBI != E; ++MBBI, ++BlockNo) { if (MBBI->getNumber() != (int)BlockNo) { // Remove use of the old number. if (MBBI->getNumber() != -1) { assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && "MBB number mismatch!"); MBBNumbering[MBBI->getNumber()] = nullptr; } // If BlockNo is already taken, set that block's number to -1. if (MBBNumbering[BlockNo]) MBBNumbering[BlockNo]->setNumber(-1); MBBNumbering[BlockNo] = &*MBBI; MBBI->setNumber(BlockNo); } } // Okay, all the blocks are renumbered. If we have compactified the block // numbering, shrink MBBNumbering now. assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); MBBNumbering.resize(BlockNo); } /// This method iterates over the basic blocks and assigns their IsBeginSection /// and IsEndSection fields. This must be called after MBB layout is finalized /// and the SectionID's are assigned to MBBs. void MachineFunction::assignBeginEndSections() { front().setIsBeginSection(); auto CurrentSectionID = front().getSectionID(); for (auto MBBI = std::next(begin()), E = end(); MBBI != E; ++MBBI) { if (MBBI->getSectionID() == CurrentSectionID) continue; MBBI->setIsBeginSection(); std::prev(MBBI)->setIsEndSection(); CurrentSectionID = MBBI->getSectionID(); } back().setIsEndSection(); } /// Allocate a new MachineInstr. Use this instead of `new MachineInstr'. MachineInstr *MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID, DebugLoc DL, bool NoImplicit) { return new (InstructionRecycler.Allocate(Allocator)) MachineInstr(*this, MCID, std::move(DL), NoImplicit); } /// Create a new MachineInstr which is a copy of the 'Orig' instruction, /// identical in all ways except the instruction has no parent, prev, or next. MachineInstr * MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { return new (InstructionRecycler.Allocate(Allocator)) MachineInstr(*this, *Orig); } MachineInstr &MachineFunction::cloneMachineInstrBundle( MachineBasicBlock &MBB, MachineBasicBlock::iterator InsertBefore, const MachineInstr &Orig) { MachineInstr *FirstClone = nullptr; MachineBasicBlock::const_instr_iterator I = Orig.getIterator(); while (true) { MachineInstr *Cloned = CloneMachineInstr(&*I); MBB.insert(InsertBefore, Cloned); if (FirstClone == nullptr) { FirstClone = Cloned; } else { Cloned->bundleWithPred(); } if (!I->isBundledWithSucc()) break; ++I; } // Copy over call site info to the cloned instruction if needed. If Orig is in // a bundle, copyCallSiteInfo takes care of finding the call instruction in // the bundle. if (Orig.shouldUpdateCallSiteInfo()) copyCallSiteInfo(&Orig, FirstClone); return *FirstClone; } /// Delete the given MachineInstr. /// /// This function also serves as the MachineInstr destructor - the real /// ~MachineInstr() destructor must be empty. void MachineFunction::deleteMachineInstr(MachineInstr *MI) { // Verify that a call site info is at valid state. This assertion should // be triggered during the implementation of support for the // call site info of a new architecture. If the assertion is triggered, // back trace will tell where to insert a call to updateCallSiteInfo(). assert((!MI->isCandidateForCallSiteEntry() || CallSitesInfo.find(MI) == CallSitesInfo.end()) && "Call site info was not updated!"); // Strip it for parts. The operand array and the MI object itself are // independently recyclable. if (MI->Operands) deallocateOperandArray(MI->CapOperands, MI->Operands); // Don't call ~MachineInstr() which must be trivial anyway because // ~MachineFunction drops whole lists of MachineInstrs wihout calling their // destructors. InstructionRecycler.Deallocate(Allocator, MI); } /// Allocate a new MachineBasicBlock. Use this instead of /// `new MachineBasicBlock'. MachineBasicBlock * MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { MachineBasicBlock *MBB = new (BasicBlockRecycler.Allocate(Allocator)) MachineBasicBlock(*this, bb); // Set BBID for `-basic-block=sections=labels` and // `-basic-block-sections=list` to allow robust mapping of profiles to basic // blocks. if (Target.getBBSectionsType() == BasicBlockSection::Labels || Target.getBBSectionsType() == BasicBlockSection::List) MBB->setBBID(NextBBID++); return MBB; } /// Delete the given MachineBasicBlock. void MachineFunction::deleteMachineBasicBlock(MachineBasicBlock *MBB) { assert(MBB->getParent() == this && "MBB parent mismatch!"); // Clean up any references to MBB in jump tables before deleting it. if (JumpTableInfo) JumpTableInfo->RemoveMBBFromJumpTables(MBB); MBB->~MachineBasicBlock(); BasicBlockRecycler.Deallocate(Allocator, MBB); } MachineMemOperand *MachineFunction::getMachineMemOperand( MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, uint64_t s, Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges, SyncScope::ID SSID, AtomicOrdering Ordering, AtomicOrdering FailureOrdering) { return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment, AAInfo, Ranges, SSID, Ordering, FailureOrdering); } MachineMemOperand *MachineFunction::getMachineMemOperand( MachinePointerInfo PtrInfo, MachineMemOperand::Flags f, LLT MemTy, Align base_alignment, const AAMDNodes &AAInfo, const MDNode *Ranges, SyncScope::ID SSID, AtomicOrdering Ordering, AtomicOrdering FailureOrdering) { return new (Allocator) MachineMemOperand(PtrInfo, f, MemTy, base_alignment, AAInfo, Ranges, SSID, Ordering, FailureOrdering); } MachineMemOperand *MachineFunction::getMachineMemOperand( const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, uint64_t Size) { return new (Allocator) MachineMemOperand(PtrInfo, MMO->getFlags(), Size, MMO->getBaseAlign(), AAMDNodes(), nullptr, MMO->getSyncScopeID(), MMO->getSuccessOrdering(), MMO->getFailureOrdering()); } MachineMemOperand *MachineFunction::getMachineMemOperand( const MachineMemOperand *MMO, const MachinePointerInfo &PtrInfo, LLT Ty) { return new (Allocator) MachineMemOperand(PtrInfo, MMO->getFlags(), Ty, MMO->getBaseAlign(), AAMDNodes(), nullptr, MMO->getSyncScopeID(), MMO->getSuccessOrdering(), MMO->getFailureOrdering()); } MachineMemOperand * MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, int64_t Offset, LLT Ty) { const MachinePointerInfo &PtrInfo = MMO->getPointerInfo(); // If there is no pointer value, the offset isn't tracked so we need to adjust // the base alignment. Align Alignment = PtrInfo.V.isNull() ? commonAlignment(MMO->getBaseAlign(), Offset) : MMO->getBaseAlign(); // Do not preserve ranges, since we don't necessarily know what the high bits // are anymore. return new (Allocator) MachineMemOperand( PtrInfo.getWithOffset(Offset), MMO->getFlags(), Ty, Alignment, MMO->getAAInfo(), nullptr, MMO->getSyncScopeID(), MMO->getSuccessOrdering(), MMO->getFailureOrdering()); } MachineMemOperand * MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, const AAMDNodes &AAInfo) { MachinePointerInfo MPI = MMO->getValue() ? MachinePointerInfo(MMO->getValue(), MMO->getOffset()) : MachinePointerInfo(MMO->getPseudoValue(), MMO->getOffset()); return new (Allocator) MachineMemOperand( MPI, MMO->getFlags(), MMO->getSize(), MMO->getBaseAlign(), AAInfo, MMO->getRanges(), MMO->getSyncScopeID(), MMO->getSuccessOrdering(), MMO->getFailureOrdering()); } MachineMemOperand * MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, MachineMemOperand::Flags Flags) { return new (Allocator) MachineMemOperand( MMO->getPointerInfo(), Flags, MMO->getSize(), MMO->getBaseAlign(), MMO->getAAInfo(), MMO->getRanges(), MMO->getSyncScopeID(), MMO->getSuccessOrdering(), MMO->getFailureOrdering()); } MachineInstr::ExtraInfo *MachineFunction::createMIExtraInfo( ArrayRef MMOs, MCSymbol *PreInstrSymbol, MCSymbol *PostInstrSymbol, MDNode *HeapAllocMarker, MDNode *PCSections, uint32_t CFIType) { return MachineInstr::ExtraInfo::create(Allocator, MMOs, PreInstrSymbol, PostInstrSymbol, HeapAllocMarker, PCSections, CFIType); } const char *MachineFunction::createExternalSymbolName(StringRef Name) { char *Dest = Allocator.Allocate(Name.size() + 1); llvm::copy(Name, Dest); Dest[Name.size()] = 0; return Dest; } uint32_t *MachineFunction::allocateRegMask() { unsigned NumRegs = getSubtarget().getRegisterInfo()->getNumRegs(); unsigned Size = MachineOperand::getRegMaskSize(NumRegs); uint32_t *Mask = Allocator.Allocate(Size); memset(Mask, 0, Size * sizeof(Mask[0])); return Mask; } ArrayRef MachineFunction::allocateShuffleMask(ArrayRef Mask) { int* AllocMask = Allocator.Allocate(Mask.size()); copy(Mask, AllocMask); return {AllocMask, Mask.size()}; } #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) LLVM_DUMP_METHOD void MachineFunction::dump() const { print(dbgs()); } #endif StringRef MachineFunction::getName() const { return getFunction().getName(); } void MachineFunction::print(raw_ostream &OS, const SlotIndexes *Indexes) const { OS << "# Machine code for function " << getName() << ": "; getProperties().print(OS); OS << '\n'; // Print Frame Information FrameInfo->print(*this, OS); // Print JumpTable Information if (JumpTableInfo) JumpTableInfo->print(OS); // Print Constant Pool ConstantPool->print(OS); const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo(); if (RegInfo && !RegInfo->livein_empty()) { OS << "Function Live Ins: "; for (MachineRegisterInfo::livein_iterator I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { OS << printReg(I->first, TRI); if (I->second) OS << " in " << printReg(I->second, TRI); if (std::next(I) != E) OS << ", "; } OS << '\n'; } ModuleSlotTracker MST(getFunction().getParent()); MST.incorporateFunction(getFunction()); for (const auto &BB : *this) { OS << '\n'; // If we print the whole function, print it at its most verbose level. BB.print(OS, MST, Indexes, /*IsStandalone=*/true); } OS << "\n# End machine code for function " << getName() << ".\n\n"; } /// True if this function needs frame moves for debug or exceptions. bool MachineFunction::needsFrameMoves() const { return getMMI().hasDebugInfo() || getTarget().Options.ForceDwarfFrameSection || F.needsUnwindTableEntry(); } namespace llvm { template<> struct DOTGraphTraits : public DefaultDOTGraphTraits { DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {} static std::string getGraphName(const MachineFunction *F) { return ("CFG for '" + F->getName() + "' function").str(); } std::string getNodeLabel(const MachineBasicBlock *Node, const MachineFunction *Graph) { std::string OutStr; { raw_string_ostream OSS(OutStr); if (isSimple()) { OSS << printMBBReference(*Node); if (const BasicBlock *BB = Node->getBasicBlock()) OSS << ": " << BB->getName(); } else Node->print(OSS); } if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); // Process string output to make it nicer... for (unsigned i = 0; i != OutStr.length(); ++i) if (OutStr[i] == '\n') { // Left justify OutStr[i] = '\\'; OutStr.insert(OutStr.begin()+i+1, 'l'); } return OutStr; } }; } // end namespace llvm void MachineFunction::viewCFG() const { #ifndef NDEBUG ViewGraph(this, "mf" + getName()); #else errs() << "MachineFunction::viewCFG is only available in debug builds on " << "systems with Graphviz or gv!\n"; #endif // NDEBUG } void MachineFunction::viewCFGOnly() const { #ifndef NDEBUG ViewGraph(this, "mf" + getName(), true); #else errs() << "MachineFunction::viewCFGOnly is only available in debug builds on " << "systems with Graphviz or gv!\n"; #endif // NDEBUG } /// Add the specified physical register as a live-in value and /// create a corresponding virtual register for it. Register MachineFunction::addLiveIn(MCRegister PReg, const TargetRegisterClass *RC) { MachineRegisterInfo &MRI = getRegInfo(); Register VReg = MRI.getLiveInVirtReg(PReg); if (VReg) { const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg); (void)VRegRC; // A physical register can be added several times. // Between two calls, the register class of the related virtual register // may have been constrained to match some operation constraints. // In that case, check that the current register class includes the // physical register and is a sub class of the specified RC. assert((VRegRC == RC || (VRegRC->contains(PReg) && RC->hasSubClassEq(VRegRC))) && "Register class mismatch!"); return VReg; } VReg = MRI.createVirtualRegister(RC); MRI.addLiveIn(PReg, VReg); return VReg; } /// Return the MCSymbol for the specified non-empty jump table. /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a /// normal 'L' label is returned. MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, bool isLinkerPrivate) const { const DataLayout &DL = getDataLayout(); assert(JumpTableInfo && "No jump tables"); assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); StringRef Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix() : DL.getPrivateGlobalPrefix(); SmallString<60> Name; raw_svector_ostream(Name) << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; return Ctx.getOrCreateSymbol(Name); } /// Return a function-local symbol to represent the PIC base. MCSymbol *MachineFunction::getPICBaseSymbol() const { const DataLayout &DL = getDataLayout(); return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "$pb"); } /// \name Exception Handling /// \{ LandingPadInfo & MachineFunction::getOrCreateLandingPadInfo(MachineBasicBlock *LandingPad) { unsigned N = LandingPads.size(); for (unsigned i = 0; i < N; ++i) { LandingPadInfo &LP = LandingPads[i]; if (LP.LandingPadBlock == LandingPad) return LP; } LandingPads.push_back(LandingPadInfo(LandingPad)); return LandingPads[N]; } void MachineFunction::addInvoke(MachineBasicBlock *LandingPad, MCSymbol *BeginLabel, MCSymbol *EndLabel) { LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); LP.BeginLabels.push_back(BeginLabel); LP.EndLabels.push_back(EndLabel); } MCSymbol *MachineFunction::addLandingPad(MachineBasicBlock *LandingPad) { MCSymbol *LandingPadLabel = Ctx.createTempSymbol(); LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); LP.LandingPadLabel = LandingPadLabel; const Instruction *FirstI = LandingPad->getBasicBlock()->getFirstNonPHI(); if (const auto *LPI = dyn_cast(FirstI)) { // If there's no typeid list specified, then "cleanup" is implicit. // Otherwise, id 0 is reserved for the cleanup action. if (LPI->isCleanup() && LPI->getNumClauses() != 0) LP.TypeIds.push_back(0); // FIXME: New EH - Add the clauses in reverse order. This isn't 100% // correct, but we need to do it this way because of how the DWARF EH // emitter processes the clauses. for (unsigned I = LPI->getNumClauses(); I != 0; --I) { Value *Val = LPI->getClause(I - 1); if (LPI->isCatch(I - 1)) { LP.TypeIds.push_back( getTypeIDFor(dyn_cast(Val->stripPointerCasts()))); } else { // Add filters in a list. auto *CVal = cast(Val); SmallVector FilterList; for (const Use &U : CVal->operands()) FilterList.push_back( getTypeIDFor(cast(U->stripPointerCasts()))); LP.TypeIds.push_back(getFilterIDFor(FilterList)); } } } else if (const auto *CPI = dyn_cast(FirstI)) { for (unsigned I = CPI->arg_size(); I != 0; --I) { auto *TypeInfo = dyn_cast(CPI->getArgOperand(I - 1)->stripPointerCasts()); LP.TypeIds.push_back(getTypeIDFor(TypeInfo)); } } else { assert(isa(FirstI) && "Invalid landingpad!"); } return LandingPadLabel; } void MachineFunction::setCallSiteLandingPad(MCSymbol *Sym, ArrayRef Sites) { LPadToCallSiteMap[Sym].append(Sites.begin(), Sites.end()); } unsigned MachineFunction::getTypeIDFor(const GlobalValue *TI) { for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i) if (TypeInfos[i] == TI) return i + 1; TypeInfos.push_back(TI); return TypeInfos.size(); } int MachineFunction::getFilterIDFor(ArrayRef TyIds) { // If the new filter coincides with the tail of an existing filter, then // re-use the existing filter. Folding filters more than this requires // re-ordering filters and/or their elements - probably not worth it. for (unsigned i : FilterEnds) { unsigned j = TyIds.size(); while (i && j) if (FilterIds[--i] != TyIds[--j]) goto try_next; if (!j) // The new filter coincides with range [i, end) of the existing filter. return -(1 + i); try_next:; } // Add the new filter. int FilterID = -(1 + FilterIds.size()); FilterIds.reserve(FilterIds.size() + TyIds.size() + 1); llvm::append_range(FilterIds, TyIds); FilterEnds.push_back(FilterIds.size()); FilterIds.push_back(0); // terminator return FilterID; } MachineFunction::CallSiteInfoMap::iterator MachineFunction::getCallSiteInfo(const MachineInstr *MI) { assert(MI->isCandidateForCallSiteEntry() && "Call site info refers only to call (MI) candidates"); if (!Target.Options.EmitCallSiteInfo) return CallSitesInfo.end(); return CallSitesInfo.find(MI); } /// Return the call machine instruction or find a call within bundle. static const MachineInstr *getCallInstr(const MachineInstr *MI) { if (!MI->isBundle()) return MI; for (const auto &BMI : make_range(getBundleStart(MI->getIterator()), getBundleEnd(MI->getIterator()))) if (BMI.isCandidateForCallSiteEntry()) return &BMI; llvm_unreachable("Unexpected bundle without a call site candidate"); } void MachineFunction::eraseCallSiteInfo(const MachineInstr *MI) { assert(MI->shouldUpdateCallSiteInfo() && "Call site info refers only to call (MI) candidates or " "candidates inside bundles"); const MachineInstr *CallMI = getCallInstr(MI); CallSiteInfoMap::iterator CSIt = getCallSiteInfo(CallMI); if (CSIt == CallSitesInfo.end()) return; CallSitesInfo.erase(CSIt); } void MachineFunction::copyCallSiteInfo(const MachineInstr *Old, const MachineInstr *New) { assert(Old->shouldUpdateCallSiteInfo() && "Call site info refers only to call (MI) candidates or " "candidates inside bundles"); if (!New->isCandidateForCallSiteEntry()) return eraseCallSiteInfo(Old); const MachineInstr *OldCallMI = getCallInstr(Old); CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI); if (CSIt == CallSitesInfo.end()) return; CallSiteInfo CSInfo = CSIt->second; CallSitesInfo[New] = CSInfo; } void MachineFunction::moveCallSiteInfo(const MachineInstr *Old, const MachineInstr *New) { assert(Old->shouldUpdateCallSiteInfo() && "Call site info refers only to call (MI) candidates or " "candidates inside bundles"); if (!New->isCandidateForCallSiteEntry()) return eraseCallSiteInfo(Old); const MachineInstr *OldCallMI = getCallInstr(Old); CallSiteInfoMap::iterator CSIt = getCallSiteInfo(OldCallMI); if (CSIt == CallSitesInfo.end()) return; CallSiteInfo CSInfo = std::move(CSIt->second); CallSitesInfo.erase(CSIt); CallSitesInfo[New] = CSInfo; } void MachineFunction::setDebugInstrNumberingCount(unsigned Num) { DebugInstrNumberingCount = Num; } void MachineFunction::makeDebugValueSubstitution(DebugInstrOperandPair A, DebugInstrOperandPair B, unsigned Subreg) { // Catch any accidental self-loops. assert(A.first != B.first); // Don't allow any substitutions _from_ the memory operand number. assert(A.second != DebugOperandMemNumber); DebugValueSubstitutions.push_back({A, B, Subreg}); } void MachineFunction::substituteDebugValuesForInst(const MachineInstr &Old, MachineInstr &New, unsigned MaxOperand) { // If the Old instruction wasn't tracked at all, there is no work to do. unsigned OldInstrNum = Old.peekDebugInstrNum(); if (!OldInstrNum) return; // Iterate over all operands looking for defs to create substitutions for. // Avoid creating new instr numbers unless we create a new substitution. // While this has no functional effect, it risks confusing someone reading // MIR output. // Examine all the operands, or the first N specified by the caller. MaxOperand = std::min(MaxOperand, Old.getNumOperands()); for (unsigned int I = 0; I < MaxOperand; ++I) { const auto &OldMO = Old.getOperand(I); auto &NewMO = New.getOperand(I); (void)NewMO; if (!OldMO.isReg() || !OldMO.isDef()) continue; assert(NewMO.isDef()); unsigned NewInstrNum = New.getDebugInstrNum(); makeDebugValueSubstitution(std::make_pair(OldInstrNum, I), std::make_pair(NewInstrNum, I)); } } auto MachineFunction::salvageCopySSA( MachineInstr &MI, DenseMap &DbgPHICache) -> DebugInstrOperandPair { const TargetInstrInfo &TII = *getSubtarget().getInstrInfo(); // Check whether this copy-like instruction has already been salvaged into // an operand pair. Register Dest; if (auto CopyDstSrc = TII.isCopyInstr(MI)) { Dest = CopyDstSrc->Destination->getReg(); } else { assert(MI.isSubregToReg()); Dest = MI.getOperand(0).getReg(); } auto CacheIt = DbgPHICache.find(Dest); if (CacheIt != DbgPHICache.end()) return CacheIt->second; // Calculate the instruction number to use, or install a DBG_PHI. auto OperandPair = salvageCopySSAImpl(MI); DbgPHICache.insert({Dest, OperandPair}); return OperandPair; } auto MachineFunction::salvageCopySSAImpl(MachineInstr &MI) -> DebugInstrOperandPair { MachineRegisterInfo &MRI = getRegInfo(); const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo(); const TargetInstrInfo &TII = *getSubtarget().getInstrInfo(); // Chase the value read by a copy-like instruction back to the instruction // that ultimately _defines_ that value. This may pass: // * Through multiple intermediate copies, including subregister moves / // copies, // * Copies from physical registers that must then be traced back to the // defining instruction, // * Or, physical registers may be live-in to (only) the entry block, which // requires a DBG_PHI to be created. // We can pursue this problem in that order: trace back through copies, // optionally through a physical register, to a defining instruction. We // should never move from physreg to vreg. As we're still in SSA form, no need // to worry about partial definitions of registers. // Helper lambda to interpret a copy-like instruction. Takes instruction, // returns the register read and any subregister identifying which part is // read. auto GetRegAndSubreg = [&](const MachineInstr &Cpy) -> std::pair { Register NewReg, OldReg; unsigned SubReg; if (Cpy.isCopy()) { OldReg = Cpy.getOperand(0).getReg(); NewReg = Cpy.getOperand(1).getReg(); SubReg = Cpy.getOperand(1).getSubReg(); } else if (Cpy.isSubregToReg()) { OldReg = Cpy.getOperand(0).getReg(); NewReg = Cpy.getOperand(2).getReg(); SubReg = Cpy.getOperand(3).getImm(); } else { auto CopyDetails = *TII.isCopyInstr(Cpy); const MachineOperand &Src = *CopyDetails.Source; const MachineOperand &Dest = *CopyDetails.Destination; OldReg = Dest.getReg(); NewReg = Src.getReg(); SubReg = Src.getSubReg(); } return {NewReg, SubReg}; }; // First seek either the defining instruction, or a copy from a physreg. // During search, the current state is the current copy instruction, and which // register we've read. Accumulate qualifying subregisters into SubregsSeen; // deal with those later. auto State = GetRegAndSubreg(MI); auto CurInst = MI.getIterator(); SmallVector SubregsSeen; while (true) { // If we've found a copy from a physreg, first portion of search is over. if (!State.first.isVirtual()) break; // Record any subregister qualifier. if (State.second) SubregsSeen.push_back(State.second); assert(MRI.hasOneDef(State.first)); MachineInstr &Inst = *MRI.def_begin(State.first)->getParent(); CurInst = Inst.getIterator(); // Any non-copy instruction is the defining instruction we're seeking. if (!Inst.isCopyLike() && !TII.isCopyInstr(Inst)) break; State = GetRegAndSubreg(Inst); }; // Helper lambda to apply additional subregister substitutions to a known // instruction/operand pair. Adds new (fake) substitutions so that we can // record the subregister. FIXME: this isn't very space efficient if multiple // values are tracked back through the same copies; cache something later. auto ApplySubregisters = [&](DebugInstrOperandPair P) -> DebugInstrOperandPair { for (unsigned Subreg : reverse(SubregsSeen)) { // Fetch a new instruction number, not attached to an actual instruction. unsigned NewInstrNumber = getNewDebugInstrNum(); // Add a substitution from the "new" number to the known one, with a // qualifying subreg. makeDebugValueSubstitution({NewInstrNumber, 0}, P, Subreg); // Return the new number; to find the underlying value, consumers need to // deal with the qualifying subreg. P = {NewInstrNumber, 0}; } return P; }; // If we managed to find the defining instruction after COPYs, return an // instruction / operand pair after adding subregister qualifiers. if (State.first.isVirtual()) { // Virtual register def -- we can just look up where this happens. MachineInstr *Inst = MRI.def_begin(State.first)->getParent(); for (auto &MO : Inst->operands()) { if (!MO.isReg() || !MO.isDef() || MO.getReg() != State.first) continue; return ApplySubregisters( {Inst->getDebugInstrNum(), Inst->getOperandNo(&MO)}); } llvm_unreachable("Vreg def with no corresponding operand?"); } // Our search ended in a copy from a physreg: walk back up the function // looking for whatever defines the physreg. assert(CurInst->isCopyLike() || TII.isCopyInstr(*CurInst)); State = GetRegAndSubreg(*CurInst); Register RegToSeek = State.first; auto RMII = CurInst->getReverseIterator(); auto PrevInstrs = make_range(RMII, CurInst->getParent()->instr_rend()); for (auto &ToExamine : PrevInstrs) { for (auto &MO : ToExamine.operands()) { // Test for operand that defines something aliasing RegToSeek. if (!MO.isReg() || !MO.isDef() || !TRI.regsOverlap(RegToSeek, MO.getReg())) continue; return ApplySubregisters( {ToExamine.getDebugInstrNum(), ToExamine.getOperandNo(&MO)}); } } MachineBasicBlock &InsertBB = *CurInst->getParent(); // We reached the start of the block before finding a defining instruction. // There are numerous scenarios where this can happen: // * Constant physical registers, // * Several intrinsics that allow LLVM-IR to read arbitary registers, // * Arguments in the entry block, // * Exception handling landing pads. // Validating all of them is too difficult, so just insert a DBG_PHI reading // the variable value at this position, rather than checking it makes sense. // Create DBG_PHI for specified physreg. auto Builder = BuildMI(InsertBB, InsertBB.getFirstNonPHI(), DebugLoc(), TII.get(TargetOpcode::DBG_PHI)); Builder.addReg(State.first); unsigned NewNum = getNewDebugInstrNum(); Builder.addImm(NewNum); return ApplySubregisters({NewNum, 0u}); } void MachineFunction::finalizeDebugInstrRefs() { auto *TII = getSubtarget().getInstrInfo(); auto MakeUndefDbgValue = [&](MachineInstr &MI) { const MCInstrDesc &RefII = TII->get(TargetOpcode::DBG_VALUE_LIST); MI.setDesc(RefII); MI.setDebugValueUndef(); }; DenseMap ArgDbgPHIs; for (auto &MBB : *this) { for (auto &MI : MBB) { if (!MI.isDebugRef()) continue; bool IsValidRef = true; for (MachineOperand &MO : MI.debug_operands()) { if (!MO.isReg()) continue; Register Reg = MO.getReg(); // Some vregs can be deleted as redundant in the meantime. Mark those // as DBG_VALUE $noreg. Additionally, some normal instructions are // quickly deleted, leaving dangling references to vregs with no def. if (Reg == 0 || !RegInfo->hasOneDef(Reg)) { IsValidRef = false; break; } assert(Reg.isVirtual()); MachineInstr &DefMI = *RegInfo->def_instr_begin(Reg); // If we've found a copy-like instruction, follow it back to the // instruction that defines the source value, see salvageCopySSA docs // for why this is important. if (DefMI.isCopyLike() || TII->isCopyInstr(DefMI)) { auto Result = salvageCopySSA(DefMI, ArgDbgPHIs); MO.ChangeToDbgInstrRef(Result.first, Result.second); } else { // Otherwise, identify the operand number that the VReg refers to. unsigned OperandIdx = 0; for (const auto &DefMO : DefMI.operands()) { if (DefMO.isReg() && DefMO.isDef() && DefMO.getReg() == Reg) break; ++OperandIdx; } assert(OperandIdx < DefMI.getNumOperands()); // Morph this instr ref to point at the given instruction and operand. unsigned ID = DefMI.getDebugInstrNum(); MO.ChangeToDbgInstrRef(ID, OperandIdx); } } if (!IsValidRef) MakeUndefDbgValue(MI); } } } bool MachineFunction::shouldUseDebugInstrRef() const { // Disable instr-ref at -O0: it's very slow (in compile time). We can still // have optimized code inlined into this unoptimized code, however with // fewer and less aggressive optimizations happening, coverage and accuracy // should not suffer. if (getTarget().getOptLevel() == CodeGenOpt::None) return false; // Don't use instr-ref if this function is marked optnone. if (F.hasFnAttribute(Attribute::OptimizeNone)) return false; if (llvm::debuginfoShouldUseDebugInstrRef(getTarget().getTargetTriple())) return true; return false; } bool MachineFunction::useDebugInstrRef() const { return UseDebugInstrRef; } void MachineFunction::setUseDebugInstrRef(bool Use) { UseDebugInstrRef = Use; } // Use one million as a high / reserved number. const unsigned MachineFunction::DebugOperandMemNumber = 1000000; /// \} //===----------------------------------------------------------------------===// // MachineJumpTableInfo implementation //===----------------------------------------------------------------------===// /// Return the size of each entry in the jump table. unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const { // The size of a jump table entry is 4 bytes unless the entry is just the // address of a block, in which case it is the pointer size. switch (getEntryKind()) { case MachineJumpTableInfo::EK_BlockAddress: return TD.getPointerSize(); case MachineJumpTableInfo::EK_GPRel64BlockAddress: return 8; case MachineJumpTableInfo::EK_GPRel32BlockAddress: case MachineJumpTableInfo::EK_LabelDifference32: case MachineJumpTableInfo::EK_Custom32: return 4; case MachineJumpTableInfo::EK_Inline: return 0; } llvm_unreachable("Unknown jump table encoding!"); } /// Return the alignment of each entry in the jump table. unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const { // The alignment of a jump table entry is the alignment of int32 unless the // entry is just the address of a block, in which case it is the pointer // alignment. switch (getEntryKind()) { case MachineJumpTableInfo::EK_BlockAddress: return TD.getPointerABIAlignment(0).value(); case MachineJumpTableInfo::EK_GPRel64BlockAddress: return TD.getABIIntegerTypeAlignment(64).value(); case MachineJumpTableInfo::EK_GPRel32BlockAddress: case MachineJumpTableInfo::EK_LabelDifference32: case MachineJumpTableInfo::EK_Custom32: return TD.getABIIntegerTypeAlignment(32).value(); case MachineJumpTableInfo::EK_Inline: return 1; } llvm_unreachable("Unknown jump table encoding!"); } /// Create a new jump table entry in the jump table info. unsigned MachineJumpTableInfo::createJumpTableIndex( const std::vector &DestBBs) { assert(!DestBBs.empty() && "Cannot create an empty jump table!"); JumpTables.push_back(MachineJumpTableEntry(DestBBs)); return JumpTables.size()-1; } /// If Old is the target of any jump tables, update the jump tables to branch /// to New instead. bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, MachineBasicBlock *New) { assert(Old != New && "Not making a change?"); bool MadeChange = false; for (size_t i = 0, e = JumpTables.size(); i != e; ++i) ReplaceMBBInJumpTable(i, Old, New); return MadeChange; } /// If MBB is present in any jump tables, remove it. bool MachineJumpTableInfo::RemoveMBBFromJumpTables(MachineBasicBlock *MBB) { bool MadeChange = false; for (MachineJumpTableEntry &JTE : JumpTables) { auto removeBeginItr = std::remove(JTE.MBBs.begin(), JTE.MBBs.end(), MBB); MadeChange |= (removeBeginItr != JTE.MBBs.end()); JTE.MBBs.erase(removeBeginItr, JTE.MBBs.end()); } return MadeChange; } /// If Old is a target of the jump tables, update the jump table to branch to /// New instead. bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, MachineBasicBlock *Old, MachineBasicBlock *New) { assert(Old != New && "Not making a change?"); bool MadeChange = false; MachineJumpTableEntry &JTE = JumpTables[Idx]; for (MachineBasicBlock *&MBB : JTE.MBBs) if (MBB == Old) { MBB = New; MadeChange = true; } return MadeChange; } void MachineJumpTableInfo::print(raw_ostream &OS) const { if (JumpTables.empty()) return; OS << "Jump Tables:\n"; for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { OS << printJumpTableEntryReference(i) << ':'; for (const MachineBasicBlock *MBB : JumpTables[i].MBBs) OS << ' ' << printMBBReference(*MBB); if (i != e) OS << '\n'; } OS << '\n'; } #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) LLVM_DUMP_METHOD void MachineJumpTableInfo::dump() const { print(dbgs()); } #endif Printable llvm::printJumpTableEntryReference(unsigned Idx) { return Printable([Idx](raw_ostream &OS) { OS << "%jump-table." << Idx; }); } //===----------------------------------------------------------------------===// // MachineConstantPool implementation //===----------------------------------------------------------------------===// void MachineConstantPoolValue::anchor() {} unsigned MachineConstantPoolValue::getSizeInBytes(const DataLayout &DL) const { return DL.getTypeAllocSize(Ty); } unsigned MachineConstantPoolEntry::getSizeInBytes(const DataLayout &DL) const { if (isMachineConstantPoolEntry()) return Val.MachineCPVal->getSizeInBytes(DL); return DL.getTypeAllocSize(Val.ConstVal->getType()); } bool MachineConstantPoolEntry::needsRelocation() const { if (isMachineConstantPoolEntry()) return true; return Val.ConstVal->needsDynamicRelocation(); } SectionKind MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const { if (needsRelocation()) return SectionKind::getReadOnlyWithRel(); switch (getSizeInBytes(*DL)) { case 4: return SectionKind::getMergeableConst4(); case 8: return SectionKind::getMergeableConst8(); case 16: return SectionKind::getMergeableConst16(); case 32: return SectionKind::getMergeableConst32(); default: return SectionKind::getReadOnly(); } } MachineConstantPool::~MachineConstantPool() { // A constant may be a member of both Constants and MachineCPVsSharingEntries, // so keep track of which we've deleted to avoid double deletions. DenseSet Deleted; for (const MachineConstantPoolEntry &C : Constants) if (C.isMachineConstantPoolEntry()) { Deleted.insert(C.Val.MachineCPVal); delete C.Val.MachineCPVal; } for (MachineConstantPoolValue *CPV : MachineCPVsSharingEntries) { if (Deleted.count(CPV) == 0) delete CPV; } } /// Test whether the given two constants can be allocated the same constant pool /// entry. static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, const DataLayout &DL) { // Handle the trivial case quickly. if (A == B) return true; // If they have the same type but weren't the same constant, quickly // reject them. if (A->getType() == B->getType()) return false; // We can't handle structs or arrays. if (isa(A->getType()) || isa(A->getType()) || isa(B->getType()) || isa(B->getType())) return false; // For now, only support constants with the same size. uint64_t StoreSize = DL.getTypeStoreSize(A->getType()); if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128) return false; Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); // Try constant folding a bitcast of both instructions to an integer. If we // get two identical ConstantInt's, then we are good to share them. We use // the constant folding APIs to do this so that we get the benefit of // DataLayout. if (isa(A->getType())) A = ConstantFoldCastOperand(Instruction::PtrToInt, const_cast(A), IntTy, DL); else if (A->getType() != IntTy) A = ConstantFoldCastOperand(Instruction::BitCast, const_cast(A), IntTy, DL); if (isa(B->getType())) B = ConstantFoldCastOperand(Instruction::PtrToInt, const_cast(B), IntTy, DL); else if (B->getType() != IntTy) B = ConstantFoldCastOperand(Instruction::BitCast, const_cast(B), IntTy, DL); return A == B; } /// Create a new entry in the constant pool or return an existing one. /// User must specify the log2 of the minimum required alignment for the object. unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, Align Alignment) { if (Alignment > PoolAlignment) PoolAlignment = Alignment; // Check to see if we already have this constant. // // FIXME, this could be made much more efficient for large constant pools. for (unsigned i = 0, e = Constants.size(); i != e; ++i) if (!Constants[i].isMachineConstantPoolEntry() && CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) { if (Constants[i].getAlign() < Alignment) Constants[i].Alignment = Alignment; return i; } Constants.push_back(MachineConstantPoolEntry(C, Alignment)); return Constants.size()-1; } unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, Align Alignment) { if (Alignment > PoolAlignment) PoolAlignment = Alignment; // Check to see if we already have this constant. // // FIXME, this could be made much more efficient for large constant pools. int Idx = V->getExistingMachineCPValue(this, Alignment); if (Idx != -1) { MachineCPVsSharingEntries.insert(V); return (unsigned)Idx; } Constants.push_back(MachineConstantPoolEntry(V, Alignment)); return Constants.size()-1; } void MachineConstantPool::print(raw_ostream &OS) const { if (Constants.empty()) return; OS << "Constant Pool:\n"; for (unsigned i = 0, e = Constants.size(); i != e; ++i) { OS << " cp#" << i << ": "; if (Constants[i].isMachineConstantPoolEntry()) Constants[i].Val.MachineCPVal->print(OS); else Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false); OS << ", align=" << Constants[i].getAlign().value(); OS << "\n"; } } #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); } #endif