Index: llvm/lib/CodeGen/PHIElimination.cpp =================================================================== --- llvm/lib/CodeGen/PHIElimination.cpp +++ llvm/lib/CodeGen/PHIElimination.cpp @@ -207,8 +207,9 @@ return false; // Quick exit for basic blocks without PHIs. // Get an iterator to the last PHI node. + // Skip debug instruction to avoid impacting PHI lower. MachineBasicBlock::iterator LastPHIIt = - std::prev(MBB.SkipPHIsAndLabels(MBB.begin())); + std::prev(MBB.SkipPHIsLabelsAndDebug(MBB.begin())); while (MBB.front().isPHI()) LowerPHINode(MBB, LastPHIIt); Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp.bk =================================================================== --- /dev/null +++ llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp.bk @@ -0,0 +1,3663 @@ +//===- SelectionDAGISel.cpp - Implement the SelectionDAGISel class --------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This implements the SelectionDAGISel class. +// +//===----------------------------------------------------------------------===// + +#include "llvm/CodeGen/SelectionDAGISel.h" +#include "ScheduleDAGSDNodes.h" +#include "SelectionDAGBuilder.h" +#include "llvm/ADT/APInt.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/None.h" +#include "llvm/ADT/PostOrderIterator.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallSet.h" +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/Analysis/BranchProbabilityInfo.h" +#include "llvm/Analysis/CFG.h" +#include "llvm/Analysis/EHPersonalities.h" +#include "llvm/Analysis/LegacyDivergenceAnalysis.h" +#include "llvm/Analysis/OptimizationRemarkEmitter.h" +#include "llvm/Analysis/TargetLibraryInfo.h" +#include "llvm/Analysis/TargetTransformInfo.h" +#include "llvm/CodeGen/FastISel.h" +#include "llvm/CodeGen/FunctionLoweringInfo.h" +#include "llvm/CodeGen/GCMetadata.h" +#include "llvm/CodeGen/ISDOpcodes.h" +#include "llvm/CodeGen/MachineBasicBlock.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineMemOperand.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/MachineOperand.h" +#include "llvm/CodeGen/MachinePassRegistry.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/SchedulerRegistry.h" +#include "llvm/CodeGen/SelectionDAG.h" +#include "llvm/CodeGen/SelectionDAGNodes.h" +#include "llvm/CodeGen/StackProtector.h" +#include "llvm/CodeGen/SwiftErrorValueTracking.h" +#include "llvm/CodeGen/TargetInstrInfo.h" +#include "llvm/CodeGen/TargetLowering.h" +#include "llvm/CodeGen/TargetRegisterInfo.h" +#include "llvm/CodeGen/TargetSubtargetInfo.h" +#include "llvm/CodeGen/ValueTypes.h" +#include "llvm/IR/BasicBlock.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DebugInfoMetadata.h" +#include "llvm/IR/DebugLoc.h" +#include "llvm/IR/DiagnosticInfo.h" +#include "llvm/IR/Dominators.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/InlineAsm.h" +#include "llvm/IR/InstIterator.h" +#include "llvm/IR/InstrTypes.h" +#include "llvm/IR/Instruction.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/Metadata.h" +#include "llvm/IR/Type.h" +#include "llvm/IR/User.h" +#include "llvm/IR/Value.h" +#include "llvm/InitializePasses.h" +#include "llvm/MC/MCInstrDesc.h" +#include "llvm/MC/MCRegisterInfo.h" +#include "llvm/Pass.h" +#include "llvm/Support/BranchProbability.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/CodeGen.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/KnownBits.h" +#include "llvm/Support/MachineValueType.h" +#include "llvm/Support/Timer.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetIntrinsicInfo.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include +#include +#include +#include +#include +#include +#include +#include +#include + +using namespace llvm; + +#define DEBUG_TYPE "isel" + +STATISTIC(NumFastIselFailures, "Number of instructions fast isel failed on"); +STATISTIC(NumFastIselSuccess, "Number of instructions fast isel selected"); +STATISTIC(NumFastIselBlocks, "Number of blocks selected entirely by fast isel"); +STATISTIC(NumDAGBlocks, "Number of blocks selected using DAG"); +STATISTIC(NumDAGIselRetries,"Number of times dag isel has to try another path"); +STATISTIC(NumEntryBlocks, "Number of entry blocks encountered"); +STATISTIC(NumFastIselFailLowerArguments, + "Number of entry blocks where fast isel failed to lower arguments"); + +static cl::opt EnableFastISelAbort( + "fast-isel-abort", cl::Hidden, + cl::desc("Enable abort calls when \"fast\" instruction selection " + "fails to lower an instruction: 0 disable the abort, 1 will " + "abort but for args, calls and terminators, 2 will also " + "abort for argument lowering, and 3 will never fallback " + "to SelectionDAG.")); + +static cl::opt EnableFastISelFallbackReport( + "fast-isel-report-on-fallback", cl::Hidden, + cl::desc("Emit a diagnostic when \"fast\" instruction selection " + "falls back to SelectionDAG.")); + +static cl::opt +UseMBPI("use-mbpi", + cl::desc("use Machine Branch Probability Info"), + cl::init(true), cl::Hidden); + +#ifndef NDEBUG +static cl::opt +FilterDAGBasicBlockName("filter-view-dags", cl::Hidden, + cl::desc("Only display the basic block whose name " + "matches this for all view-*-dags options")); +static cl::opt +ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden, + cl::desc("Pop up a window to show dags before the first " + "dag combine pass")); +static cl::opt +ViewLegalizeTypesDAGs("view-legalize-types-dags", cl::Hidden, + cl::desc("Pop up a window to show dags before legalize types")); +static cl::opt +ViewLegalizeDAGs("view-legalize-dags", cl::Hidden, + cl::desc("Pop up a window to show dags before legalize")); +static cl::opt +ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden, + cl::desc("Pop up a window to show dags before the second " + "dag combine pass")); +static cl::opt +ViewDAGCombineLT("view-dag-combine-lt-dags", cl::Hidden, + cl::desc("Pop up a window to show dags before the post legalize types" + " dag combine pass")); +static cl::opt +ViewISelDAGs("view-isel-dags", cl::Hidden, + cl::desc("Pop up a window to show isel dags as they are selected")); +static cl::opt +ViewSchedDAGs("view-sched-dags", cl::Hidden, + cl::desc("Pop up a window to show sched dags as they are processed")); +static cl::opt +ViewSUnitDAGs("view-sunit-dags", cl::Hidden, + cl::desc("Pop up a window to show SUnit dags after they are processed")); +#else +static const bool ViewDAGCombine1 = false, + ViewLegalizeTypesDAGs = false, ViewLegalizeDAGs = false, + ViewDAGCombine2 = false, + ViewDAGCombineLT = false, + ViewISelDAGs = false, ViewSchedDAGs = false, + ViewSUnitDAGs = false; +#endif + +//===---------------------------------------------------------------------===// +/// +/// RegisterScheduler class - Track the registration of instruction schedulers. +/// +//===---------------------------------------------------------------------===// +MachinePassRegistry + RegisterScheduler::Registry; + +//===---------------------------------------------------------------------===// +/// +/// ISHeuristic command line option for instruction schedulers. +/// +//===---------------------------------------------------------------------===// +static cl::opt> +ISHeuristic("pre-RA-sched", + cl::init(&createDefaultScheduler), cl::Hidden, + cl::desc("Instruction schedulers available (before register" + " allocation):")); + +static RegisterScheduler +defaultListDAGScheduler("default", "Best scheduler for the target", + createDefaultScheduler); + +namespace llvm { + + //===--------------------------------------------------------------------===// + /// This class is used by SelectionDAGISel to temporarily override + /// the optimization level on a per-function basis. + class OptLevelChanger { + SelectionDAGISel &IS; + CodeGenOpt::Level SavedOptLevel; + bool SavedFastISel; + + public: + OptLevelChanger(SelectionDAGISel &ISel, + CodeGenOpt::Level NewOptLevel) : IS(ISel) { + SavedOptLevel = IS.OptLevel; + if (NewOptLevel == SavedOptLevel) + return; + IS.OptLevel = NewOptLevel; + IS.TM.setOptLevel(NewOptLevel); + LLVM_DEBUG(dbgs() << "\nChanging optimization level for Function " + << IS.MF->getFunction().getName() << "\n"); + LLVM_DEBUG(dbgs() << "\tBefore: -O" << SavedOptLevel << " ; After: -O" + << NewOptLevel << "\n"); + SavedFastISel = IS.TM.Options.EnableFastISel; + if (NewOptLevel == CodeGenOpt::None) { + IS.TM.setFastISel(IS.TM.getO0WantsFastISel()); + LLVM_DEBUG( + dbgs() << "\tFastISel is " + << (IS.TM.Options.EnableFastISel ? "enabled" : "disabled") + << "\n"); + } + } + + ~OptLevelChanger() { + if (IS.OptLevel == SavedOptLevel) + return; + LLVM_DEBUG(dbgs() << "\nRestoring optimization level for Function " + << IS.MF->getFunction().getName() << "\n"); + LLVM_DEBUG(dbgs() << "\tBefore: -O" << IS.OptLevel << " ; After: -O" + << SavedOptLevel << "\n"); + IS.OptLevel = SavedOptLevel; + IS.TM.setOptLevel(SavedOptLevel); + IS.TM.setFastISel(SavedFastISel); + } + }; + + //===--------------------------------------------------------------------===// + /// createDefaultScheduler - This creates an instruction scheduler appropriate + /// for the target. + ScheduleDAGSDNodes* createDefaultScheduler(SelectionDAGISel *IS, + CodeGenOpt::Level OptLevel) { + const TargetLowering *TLI = IS->TLI; + const TargetSubtargetInfo &ST = IS->MF->getSubtarget(); + + // Try first to see if the Target has its own way of selecting a scheduler + if (auto *SchedulerCtor = ST.getDAGScheduler(OptLevel)) { + return SchedulerCtor(IS, OptLevel); + } + + if (OptLevel == CodeGenOpt::None || + (ST.enableMachineScheduler() && ST.enableMachineSchedDefaultSched()) || + TLI->getSchedulingPreference() == Sched::Source) + return createSourceListDAGScheduler(IS, OptLevel); + if (TLI->getSchedulingPreference() == Sched::RegPressure) + return createBURRListDAGScheduler(IS, OptLevel); + if (TLI->getSchedulingPreference() == Sched::Hybrid) + return createHybridListDAGScheduler(IS, OptLevel); + if (TLI->getSchedulingPreference() == Sched::VLIW) + return createVLIWDAGScheduler(IS, OptLevel); + assert(TLI->getSchedulingPreference() == Sched::ILP && + "Unknown sched type!"); + return createILPListDAGScheduler(IS, OptLevel); + } + +} // end namespace llvm + +// EmitInstrWithCustomInserter - This method should be implemented by targets +// that mark instructions with the 'usesCustomInserter' flag. These +// instructions are special in various ways, which require special support to +// insert. The specified MachineInstr is created but not inserted into any +// basic blocks, and this method is called to expand it into a sequence of +// instructions, potentially also creating new basic blocks and control flow. +// When new basic blocks are inserted and the edges from MBB to its successors +// are modified, the method should insert pairs of into the +// DenseMap. +MachineBasicBlock * +TargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI, + MachineBasicBlock *MBB) const { +#ifndef NDEBUG + dbgs() << "If a target marks an instruction with " + "'usesCustomInserter', it must implement " + "TargetLowering::EmitInstrWithCustomInserter!"; +#endif + llvm_unreachable(nullptr); +} + +void TargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI, + SDNode *Node) const { + assert(!MI.hasPostISelHook() && + "If a target marks an instruction with 'hasPostISelHook', " + "it must implement TargetLowering::AdjustInstrPostInstrSelection!"); +} + +//===----------------------------------------------------------------------===// +// SelectionDAGISel code +//===----------------------------------------------------------------------===// + +SelectionDAGISel::SelectionDAGISel(TargetMachine &tm, CodeGenOpt::Level OL) + : MachineFunctionPass(ID), TM(tm), FuncInfo(new FunctionLoweringInfo()), + SwiftError(new SwiftErrorValueTracking()), + CurDAG(new SelectionDAG(tm, OL)), + SDB(new SelectionDAGBuilder(*CurDAG, *FuncInfo, *SwiftError, OL)), AA(), + GFI(), OptLevel(OL), DAGSize(0) { + initializeGCModuleInfoPass(*PassRegistry::getPassRegistry()); + initializeBranchProbabilityInfoWrapperPassPass( + *PassRegistry::getPassRegistry()); + initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry()); + initializeTargetLibraryInfoWrapperPassPass(*PassRegistry::getPassRegistry()); +} + +SelectionDAGISel::~SelectionDAGISel() { + delete SDB; + delete CurDAG; + delete FuncInfo; + delete SwiftError; +} + +void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const { + if (OptLevel != CodeGenOpt::None) + AU.addRequired(); + AU.addRequired(); + AU.addRequired(); + AU.addPreserved(); + AU.addRequired(); + AU.addRequired(); + if (UseMBPI && OptLevel != CodeGenOpt::None) + AU.addRequired(); + MachineFunctionPass::getAnalysisUsage(AU); +} + +/// SplitCriticalSideEffectEdges - Look for critical edges with a PHI value that +/// may trap on it. In this case we have to split the edge so that the path +/// through the predecessor block that doesn't go to the phi block doesn't +/// execute the possibly trapping instruction. If available, we pass domtree +/// and loop info to be updated when we split critical edges. This is because +/// SelectionDAGISel preserves these analyses. +/// This is required for correctness, so it must be done at -O0. +/// +static void SplitCriticalSideEffectEdges(Function &Fn, DominatorTree *DT, + LoopInfo *LI) { + // Loop for blocks with phi nodes. + for (BasicBlock &BB : Fn) { + PHINode *PN = dyn_cast(BB.begin()); + if (!PN) continue; + + ReprocessBlock: + // For each block with a PHI node, check to see if any of the input values + // are potentially trapping constant expressions. Constant expressions are + // the only potentially trapping value that can occur as the argument to a + // PHI. + for (BasicBlock::iterator I = BB.begin(); (PN = dyn_cast(I)); ++I) + for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { + ConstantExpr *CE = dyn_cast(PN->getIncomingValue(i)); + if (!CE || !CE->canTrap()) continue; + + // The only case we have to worry about is when the edge is critical. + // Since this block has a PHI Node, we assume it has multiple input + // edges: check to see if the pred has multiple successors. + BasicBlock *Pred = PN->getIncomingBlock(i); + if (Pred->getTerminator()->getNumSuccessors() == 1) + continue; + + // Okay, we have to split this edge. + SplitCriticalEdge( + Pred->getTerminator(), GetSuccessorNumber(Pred, &BB), + CriticalEdgeSplittingOptions(DT, LI).setMergeIdenticalEdges()); + goto ReprocessBlock; + } + } +} + +static void computeUsesMSVCFloatingPoint(const Triple &TT, const Function &F, + MachineModuleInfo &MMI) { + // Only needed for MSVC + if (!TT.isWindowsMSVCEnvironment()) + return; + + // If it's already set, nothing to do. + if (MMI.usesMSVCFloatingPoint()) + return; + + for (const Instruction &I : instructions(F)) { + if (I.getType()->isFPOrFPVectorTy()) { + MMI.setUsesMSVCFloatingPoint(true); + return; + } + for (const auto &Op : I.operands()) { + if (Op->getType()->isFPOrFPVectorTy()) { + MMI.setUsesMSVCFloatingPoint(true); + return; + } + } + } +} + +bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) { + // If we already selected that function, we do not need to run SDISel. + if (mf.getProperties().hasProperty( + MachineFunctionProperties::Property::Selected)) + return false; + // Do some sanity-checking on the command-line options. + assert((!EnableFastISelAbort || TM.Options.EnableFastISel) && + "-fast-isel-abort > 0 requires -fast-isel"); + + const Function &Fn = mf.getFunction(); + MF = &mf; + + // Reset the target options before resetting the optimization + // level below. + // FIXME: This is a horrible hack and should be processed via + // codegen looking at the optimization level explicitly when + // it wants to look at it. + TM.resetTargetOptions(Fn); + // Reset OptLevel to None for optnone functions. + CodeGenOpt::Level NewOptLevel = OptLevel; + if (OptLevel != CodeGenOpt::None && skipFunction(Fn)) + NewOptLevel = CodeGenOpt::None; + OptLevelChanger OLC(*this, NewOptLevel); + + TII = MF->getSubtarget().getInstrInfo(); + TLI = MF->getSubtarget().getTargetLowering(); + RegInfo = &MF->getRegInfo(); + LibInfo = &getAnalysis().getTLI(Fn); + GFI = Fn.hasGC() ? &getAnalysis().getFunctionInfo(Fn) : nullptr; + ORE = std::make_unique(&Fn); + auto *DTWP = getAnalysisIfAvailable(); + DominatorTree *DT = DTWP ? &DTWP->getDomTree() : nullptr; + auto *LIWP = getAnalysisIfAvailable(); + LoopInfo *LI = LIWP ? &LIWP->getLoopInfo() : nullptr; + + LLVM_DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n"); + + SplitCriticalSideEffectEdges(const_cast(Fn), DT, LI); + + CurDAG->init(*MF, *ORE, this, LibInfo, + getAnalysisIfAvailable()); + FuncInfo->set(Fn, *MF, CurDAG); + SwiftError->setFunction(*MF); + + // Now get the optional analyzes if we want to. + // This is based on the possibly changed OptLevel (after optnone is taken + // into account). That's unfortunate but OK because it just means we won't + // ask for passes that have been required anyway. + + if (UseMBPI && OptLevel != CodeGenOpt::None) + FuncInfo->BPI = &getAnalysis().getBPI(); + else + FuncInfo->BPI = nullptr; + + if (OptLevel != CodeGenOpt::None) + AA = &getAnalysis().getAAResults(); + else + AA = nullptr; + + SDB->init(GFI, AA, LibInfo); + + MF->setHasInlineAsm(false); + + FuncInfo->SplitCSR = false; + + // We split CSR if the target supports it for the given function + // and the function has only return exits. + if (OptLevel != CodeGenOpt::None && TLI->supportSplitCSR(MF)) { + FuncInfo->SplitCSR = true; + + // Collect all the return blocks. + for (const BasicBlock &BB : Fn) { + if (!succ_empty(&BB)) + continue; + + const Instruction *Term = BB.getTerminator(); + if (isa(Term) || isa(Term)) + continue; + + // Bail out if the exit block is not Return nor Unreachable. + FuncInfo->SplitCSR = false; + break; + } + } + + MachineBasicBlock *EntryMBB = &MF->front(); + if (FuncInfo->SplitCSR) + // This performs initialization so lowering for SplitCSR will be correct. + TLI->initializeSplitCSR(EntryMBB); + + SelectAllBasicBlocks(Fn); + if (FastISelFailed && EnableFastISelFallbackReport) { + DiagnosticInfoISelFallback DiagFallback(Fn); + Fn.getContext().diagnose(DiagFallback); + } + + // Replace forward-declared registers with the registers containing + // the desired value. + // Note: it is important that this happens **before** the call to + // EmitLiveInCopies, since implementations can skip copies of unused + // registers. If we don't apply the reg fixups before, some registers may + // appear as unused and will be skipped, resulting in bad MI. + MachineRegisterInfo &MRI = MF->getRegInfo(); + for (DenseMap::iterator I = FuncInfo->RegFixups.begin(), + E = FuncInfo->RegFixups.end(); + I != E; ++I) { + unsigned From = I->first; + unsigned To = I->second; + // If To is also scheduled to be replaced, find what its ultimate + // replacement is. + while (true) { + DenseMap::iterator J = FuncInfo->RegFixups.find(To); + if (J == E) + break; + To = J->second; + } + // Make sure the new register has a sufficiently constrained register class. + if (Register::isVirtualRegister(From) && Register::isVirtualRegister(To)) + MRI.constrainRegClass(To, MRI.getRegClass(From)); + // Replace it. + + // Replacing one register with another won't touch the kill flags. + // We need to conservatively clear the kill flags as a kill on the old + // register might dominate existing uses of the new register. + if (!MRI.use_empty(To)) + MRI.clearKillFlags(From); + MRI.replaceRegWith(From, To); + } + + // If the first basic block in the function has live ins that need to be + // copied into vregs, emit the copies into the top of the block before + // emitting the code for the block. + const TargetRegisterInfo &TRI = *MF->getSubtarget().getRegisterInfo(); + RegInfo->EmitLiveInCopies(EntryMBB, TRI, *TII); + + // Insert copies in the entry block and the return blocks. + if (FuncInfo->SplitCSR) { + SmallVector Returns; + // Collect all the return blocks. + for (MachineBasicBlock &MBB : mf) { + if (!MBB.succ_empty()) + continue; + + MachineBasicBlock::iterator Term = MBB.getFirstTerminator(); + if (Term != MBB.end() && Term->isReturn()) { + Returns.push_back(&MBB); + continue; + } + } + TLI->insertCopiesSplitCSR(EntryMBB, Returns); + } + + DenseMap LiveInMap; + if (!FuncInfo->ArgDbgValues.empty()) + for (std::pair LI : RegInfo->liveins()) + if (LI.second) + LiveInMap.insert(LI); + + // Insert DBG_VALUE instructions for function arguments to the entry block. + for (unsigned i = 0, e = FuncInfo->ArgDbgValues.size(); i != e; ++i) { + MachineInstr *MI = FuncInfo->ArgDbgValues[e-i-1]; + bool hasFI = MI->getOperand(0).isFI(); + Register Reg = + hasFI ? TRI.getFrameRegister(*MF) : MI->getOperand(0).getReg(); + if (Register::isPhysicalRegister(Reg)) + EntryMBB->insert(EntryMBB->begin(), MI); + else { + MachineInstr *Def = RegInfo->getVRegDef(Reg); + if (Def) { + MachineBasicBlock::iterator InsertPos = Def; + // FIXME: VR def may not be in entry block. + Def->getParent()->insert(std::next(InsertPos), MI); + } else + LLVM_DEBUG(dbgs() << "Dropping debug info for dead vreg" + << Register::virtReg2Index(Reg) << "\n"); + } + + // If Reg is live-in then update debug info to track its copy in a vreg. + DenseMap::iterator LDI = LiveInMap.find(Reg); + if (LDI != LiveInMap.end()) { + assert(!hasFI && "There's no handling of frame pointer updating here yet " + "- add if needed"); + MachineInstr *Def = RegInfo->getVRegDef(LDI->second); + MachineBasicBlock::iterator InsertPos = Def; + const MDNode *Variable = MI->getDebugVariable(); + const MDNode *Expr = MI->getDebugExpression(); + DebugLoc DL = MI->getDebugLoc(); + bool IsIndirect = MI->isIndirectDebugValue(); + if (IsIndirect) + assert(MI->getOperand(1).getImm() == 0 && + "DBG_VALUE with nonzero offset"); + assert(cast(Variable)->isValidLocationForIntrinsic(DL) && + "Expected inlined-at fields to agree"); + // Def is never a terminator here, so it is ok to increment InsertPos. + BuildMI(*EntryMBB, ++InsertPos, DL, TII->get(TargetOpcode::DBG_VALUE), + IsIndirect, LDI->second, Variable, Expr); + + // If this vreg is directly copied into an exported register then + // that COPY instructions also need DBG_VALUE, if it is the only + // user of LDI->second. + MachineInstr *CopyUseMI = nullptr; + for (MachineRegisterInfo::use_instr_iterator + UI = RegInfo->use_instr_begin(LDI->second), + E = RegInfo->use_instr_end(); UI != E; ) { + MachineInstr *UseMI = &*(UI++); + if (UseMI->isDebugValue()) continue; + if (UseMI->isCopy() && !CopyUseMI && UseMI->getParent() == EntryMBB) { + CopyUseMI = UseMI; continue; + } + // Otherwise this is another use or second copy use. + CopyUseMI = nullptr; break; + } + if (CopyUseMI) { + // Use MI's debug location, which describes where Variable was + // declared, rather than whatever is attached to CopyUseMI. + MachineInstr *NewMI = + BuildMI(*MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsIndirect, + CopyUseMI->getOperand(0).getReg(), Variable, Expr); + MachineBasicBlock::iterator Pos = CopyUseMI; + EntryMBB->insertAfter(Pos, NewMI); + } + } + } + + // Determine if there are any calls in this machine function. + MachineFrameInfo &MFI = MF->getFrameInfo(); + for (const auto &MBB : *MF) { + if (MFI.hasCalls() && MF->hasInlineAsm()) + break; + + for (const auto &MI : MBB) { + const MCInstrDesc &MCID = TII->get(MI.getOpcode()); + if ((MCID.isCall() && !MCID.isReturn()) || + MI.isStackAligningInlineAsm()) { + MFI.setHasCalls(true); + } + if (MI.isInlineAsm()) { + MF->setHasInlineAsm(true); + } + } + } + + // Determine if there is a call to setjmp in the machine function. + MF->setExposesReturnsTwice(Fn.callsFunctionThatReturnsTwice()); + + // Determine if floating point is used for msvc + computeUsesMSVCFloatingPoint(TM.getTargetTriple(), Fn, MF->getMMI()); + + // Replace forward-declared registers with the registers containing + // the desired value. + for (DenseMap::iterator + I = FuncInfo->RegFixups.begin(), E = FuncInfo->RegFixups.end(); + I != E; ++I) { + unsigned From = I->first; + unsigned To = I->second; + // If To is also scheduled to be replaced, find what its ultimate + // replacement is. + while (true) { + DenseMap::iterator J = FuncInfo->RegFixups.find(To); + if (J == E) break; + To = J->second; + } + // Make sure the new register has a sufficiently constrained register class. + if (Register::isVirtualRegister(From) && Register::isVirtualRegister(To)) + MRI.constrainRegClass(To, MRI.getRegClass(From)); + // Replace it. + + + // Replacing one register with another won't touch the kill flags. + // We need to conservatively clear the kill flags as a kill on the old + // register might dominate existing uses of the new register. + if (!MRI.use_empty(To)) + MRI.clearKillFlags(From); + MRI.replaceRegWith(From, To); + } + + TLI->finalizeLowering(*MF); + + // Release function-specific state. SDB and CurDAG are already cleared + // at this point. + FuncInfo->clear(); + + LLVM_DEBUG(dbgs() << "*** MachineFunction at end of ISel ***\n"); + LLVM_DEBUG(MF->print(dbgs())); + + return true; +} + +static void reportFastISelFailure(MachineFunction &MF, + OptimizationRemarkEmitter &ORE, + OptimizationRemarkMissed &R, + bool ShouldAbort) { + // 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() || ShouldAbort) + R << (" (in function: " + MF.getName() + ")").str(); + + if (ShouldAbort) + report_fatal_error(R.getMsg()); + + ORE.emit(R); +} + +void SelectionDAGISel::SelectBasicBlock(BasicBlock::const_iterator Begin, + BasicBlock::const_iterator End, + bool &HadTailCall) { + // Allow creating illegal types during DAG building for the basic block. + CurDAG->NewNodesMustHaveLegalTypes = false; + + // Lower the instructions. If a call is emitted as a tail call, cease emitting + // nodes for this block. + for (BasicBlock::const_iterator I = Begin; I != End && !SDB->HasTailCall; ++I) { + if (!ElidedArgCopyInstrs.count(&*I)) + SDB->visit(*I); + } + + // Make sure the root of the DAG is up-to-date. + CurDAG->setRoot(SDB->getControlRoot()); + HadTailCall = SDB->HasTailCall; + SDB->resolveOrClearDbgInfo(); + SDB->clear(); + + // Final step, emit the lowered DAG as machine code. + CodeGenAndEmitDAG(); +} + +void SelectionDAGISel::ComputeLiveOutVRegInfo() { + SmallPtrSet VisitedNodes; + SmallVector Worklist; + + Worklist.push_back(CurDAG->getRoot().getNode()); + + KnownBits Known; + + do { + SDNode *N = Worklist.pop_back_val(); + + // If we've already seen this node, ignore it. + if (!VisitedNodes.insert(N).second) + continue; + + // Otherwise, add all chain operands to the worklist. + for (const SDValue &Op : N->op_values()) + if (Op.getValueType() == MVT::Other) + Worklist.push_back(Op.getNode()); + + // If this is a CopyToReg with a vreg dest, process it. + if (N->getOpcode() != ISD::CopyToReg) + continue; + + unsigned DestReg = cast(N->getOperand(1))->getReg(); + if (!Register::isVirtualRegister(DestReg)) + continue; + + // Ignore non-integer values. + SDValue Src = N->getOperand(2); + EVT SrcVT = Src.getValueType(); + if (!SrcVT.isInteger()) + continue; + + unsigned NumSignBits = CurDAG->ComputeNumSignBits(Src); + Known = CurDAG->computeKnownBits(Src); + FuncInfo->AddLiveOutRegInfo(DestReg, NumSignBits, Known); + } while (!Worklist.empty()); +} + +void SelectionDAGISel::CodeGenAndEmitDAG() { + StringRef GroupName = "sdag"; + StringRef GroupDescription = "Instruction Selection and Scheduling"; + std::string BlockName; + bool MatchFilterBB = false; (void)MatchFilterBB; +#ifndef NDEBUG + TargetTransformInfo &TTI = + getAnalysis().getTTI(*FuncInfo->Fn); +#endif + + // Pre-type legalization allow creation of any node types. + CurDAG->NewNodesMustHaveLegalTypes = false; + +#ifndef NDEBUG + MatchFilterBB = (FilterDAGBasicBlockName.empty() || + FilterDAGBasicBlockName == + FuncInfo->MBB->getBasicBlock()->getName()); +#endif +#ifdef NDEBUG + if (ViewDAGCombine1 || ViewLegalizeTypesDAGs || ViewLegalizeDAGs || + ViewDAGCombine2 || ViewDAGCombineLT || ViewISelDAGs || ViewSchedDAGs || + ViewSUnitDAGs) +#endif + { + BlockName = + (MF->getName() + ":" + FuncInfo->MBB->getBasicBlock()->getName()).str(); + } + LLVM_DEBUG(dbgs() << "Initial selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + if (ViewDAGCombine1 && MatchFilterBB) + CurDAG->viewGraph("dag-combine1 input for " + BlockName); + + // Run the DAG combiner in pre-legalize mode. + { + NamedRegionTimer T("combine1", "DAG Combining 1", GroupName, + GroupDescription, TimePassesIsEnabled); + CurDAG->Combine(BeforeLegalizeTypes, AA, OptLevel); + } + +#ifndef NDEBUG + if (TTI.hasBranchDivergence()) + CurDAG->VerifyDAGDiverence(); +#endif + + LLVM_DEBUG(dbgs() << "Optimized lowered selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + // Second step, hack on the DAG until it only uses operations and types that + // the target supports. + if (ViewLegalizeTypesDAGs && MatchFilterBB) + CurDAG->viewGraph("legalize-types input for " + BlockName); + + bool Changed; + { + NamedRegionTimer T("legalize_types", "Type Legalization", GroupName, + GroupDescription, TimePassesIsEnabled); + Changed = CurDAG->LegalizeTypes(); + } + +#ifndef NDEBUG + if (TTI.hasBranchDivergence()) + CurDAG->VerifyDAGDiverence(); +#endif + + LLVM_DEBUG(dbgs() << "Type-legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + // Only allow creation of legal node types. + CurDAG->NewNodesMustHaveLegalTypes = true; + + if (Changed) { + if (ViewDAGCombineLT && MatchFilterBB) + CurDAG->viewGraph("dag-combine-lt input for " + BlockName); + + // Run the DAG combiner in post-type-legalize mode. + { + NamedRegionTimer T("combine_lt", "DAG Combining after legalize types", + GroupName, GroupDescription, TimePassesIsEnabled); + CurDAG->Combine(AfterLegalizeTypes, AA, OptLevel); + } + +#ifndef NDEBUG + if (TTI.hasBranchDivergence()) + CurDAG->VerifyDAGDiverence(); +#endif + + LLVM_DEBUG(dbgs() << "Optimized type-legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + } + + { + NamedRegionTimer T("legalize_vec", "Vector Legalization", GroupName, + GroupDescription, TimePassesIsEnabled); + Changed = CurDAG->LegalizeVectors(); + } + + if (Changed) { + LLVM_DEBUG(dbgs() << "Vector-legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + { + NamedRegionTimer T("legalize_types2", "Type Legalization 2", GroupName, + GroupDescription, TimePassesIsEnabled); + CurDAG->LegalizeTypes(); + } + + LLVM_DEBUG(dbgs() << "Vector/type-legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + if (ViewDAGCombineLT && MatchFilterBB) + CurDAG->viewGraph("dag-combine-lv input for " + BlockName); + + // Run the DAG combiner in post-type-legalize mode. + { + NamedRegionTimer T("combine_lv", "DAG Combining after legalize vectors", + GroupName, GroupDescription, TimePassesIsEnabled); + CurDAG->Combine(AfterLegalizeVectorOps, AA, OptLevel); + } + + LLVM_DEBUG(dbgs() << "Optimized vector-legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + +#ifndef NDEBUG + if (TTI.hasBranchDivergence()) + CurDAG->VerifyDAGDiverence(); +#endif + } + + if (ViewLegalizeDAGs && MatchFilterBB) + CurDAG->viewGraph("legalize input for " + BlockName); + + { + NamedRegionTimer T("legalize", "DAG Legalization", GroupName, + GroupDescription, TimePassesIsEnabled); + CurDAG->Legalize(); + } + +#ifndef NDEBUG + if (TTI.hasBranchDivergence()) + CurDAG->VerifyDAGDiverence(); +#endif + + LLVM_DEBUG(dbgs() << "Legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + if (ViewDAGCombine2 && MatchFilterBB) + CurDAG->viewGraph("dag-combine2 input for " + BlockName); + + // Run the DAG combiner in post-legalize mode. + { + NamedRegionTimer T("combine2", "DAG Combining 2", GroupName, + GroupDescription, TimePassesIsEnabled); + CurDAG->Combine(AfterLegalizeDAG, AA, OptLevel); + } + +#ifndef NDEBUG + if (TTI.hasBranchDivergence()) + CurDAG->VerifyDAGDiverence(); +#endif + + LLVM_DEBUG(dbgs() << "Optimized legalized selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + if (OptLevel != CodeGenOpt::None) + ComputeLiveOutVRegInfo(); + + if (ViewISelDAGs && MatchFilterBB) + CurDAG->viewGraph("isel input for " + BlockName); + + // Third, instruction select all of the operations to machine code, adding the + // code to the MachineBasicBlock. + { + NamedRegionTimer T("isel", "Instruction Selection", GroupName, + GroupDescription, TimePassesIsEnabled); + DoInstructionSelection(); + } + + LLVM_DEBUG(dbgs() << "Selected selection DAG: " + << printMBBReference(*FuncInfo->MBB) << " '" << BlockName + << "'\n"; + CurDAG->dump()); + + if (ViewSchedDAGs && MatchFilterBB) + CurDAG->viewGraph("scheduler input for " + BlockName); + + // Schedule machine code. + ScheduleDAGSDNodes *Scheduler = CreateScheduler(); + { + NamedRegionTimer T("sched", "Instruction Scheduling", GroupName, + GroupDescription, TimePassesIsEnabled); + Scheduler->Run(CurDAG, FuncInfo->MBB); + } + + if (ViewSUnitDAGs && MatchFilterBB) + Scheduler->viewGraph(); + + // Emit machine code to BB. This can change 'BB' to the last block being + // inserted into. + MachineBasicBlock *FirstMBB = FuncInfo->MBB, *LastMBB; + { + NamedRegionTimer T("emit", "Instruction Creation", GroupName, + GroupDescription, TimePassesIsEnabled); + + // FuncInfo->InsertPt is passed by reference and set to the end of the + // scheduled instructions. + LastMBB = FuncInfo->MBB = Scheduler->EmitSchedule(FuncInfo->InsertPt); + } + + // If the block was split, make sure we update any references that are used to + // update PHI nodes later on. + if (FirstMBB != LastMBB) + SDB->UpdateSplitBlock(FirstMBB, LastMBB); + + // Free the scheduler state. + { + NamedRegionTimer T("cleanup", "Instruction Scheduling Cleanup", GroupName, + GroupDescription, TimePassesIsEnabled); + delete Scheduler; + } + + // Free the SelectionDAG state, now that we're finished with it. + CurDAG->clear(); +} + +namespace { + +/// ISelUpdater - helper class to handle updates of the instruction selection +/// graph. +class ISelUpdater : public SelectionDAG::DAGUpdateListener { + SelectionDAG::allnodes_iterator &ISelPosition; + +public: + ISelUpdater(SelectionDAG &DAG, SelectionDAG::allnodes_iterator &isp) + : SelectionDAG::DAGUpdateListener(DAG), ISelPosition(isp) {} + + /// NodeDeleted - Handle nodes deleted from the graph. If the node being + /// deleted is the current ISelPosition node, update ISelPosition. + /// + void NodeDeleted(SDNode *N, SDNode *E) override { + if (ISelPosition == SelectionDAG::allnodes_iterator(N)) + ++ISelPosition; + } +}; + +} // end anonymous namespace + +// This function is used to enforce the topological node id property +// property leveraged during Instruction selection. Before selection all +// nodes are given a non-negative id such that all nodes have a larger id than +// their operands. As this holds transitively we can prune checks that a node N +// is a predecessor of M another by not recursively checking through M's +// operands if N's ID is larger than M's ID. This is significantly improves +// performance of for various legality checks (e.g. IsLegalToFold / +// UpdateChains). + +// However, when we fuse multiple nodes into a single node +// during selection we may induce a predecessor relationship between inputs and +// outputs of distinct nodes being merged violating the topological property. +// Should a fused node have a successor which has yet to be selected, our +// legality checks would be incorrect. To avoid this we mark all unselected +// sucessor nodes, i.e. id != -1 as invalid for pruning by bit-negating (x => +// (-(x+1))) the ids and modify our pruning check to ignore negative Ids of M. +// We use bit-negation to more clearly enforce that node id -1 can only be +// achieved by selected nodes). As the conversion is reversable the original Id, +// topological pruning can still be leveraged when looking for unselected nodes. +// This method is call internally in all ISel replacement calls. +void SelectionDAGISel::EnforceNodeIdInvariant(SDNode *Node) { + SmallVector Nodes; + Nodes.push_back(Node); + + while (!Nodes.empty()) { + SDNode *N = Nodes.pop_back_val(); + for (auto *U : N->uses()) { + auto UId = U->getNodeId(); + if (UId > 0) { + InvalidateNodeId(U); + Nodes.push_back(U); + } + } + } +} + +// InvalidateNodeId - As discusses in EnforceNodeIdInvariant, mark a +// NodeId with the equivalent node id which is invalid for topological +// pruning. +void SelectionDAGISel::InvalidateNodeId(SDNode *N) { + int InvalidId = -(N->getNodeId() + 1); + N->setNodeId(InvalidId); +} + +// getUninvalidatedNodeId - get original uninvalidated node id. +int SelectionDAGISel::getUninvalidatedNodeId(SDNode *N) { + int Id = N->getNodeId(); + if (Id < -1) + return -(Id + 1); + return Id; +} + +void SelectionDAGISel::DoInstructionSelection() { + LLVM_DEBUG(dbgs() << "===== Instruction selection begins: " + << printMBBReference(*FuncInfo->MBB) << " '" + << FuncInfo->MBB->getName() << "'\n"); + + PreprocessISelDAG(); + + // Select target instructions for the DAG. + { + // Number all nodes with a topological order and set DAGSize. + DAGSize = CurDAG->AssignTopologicalOrder(); + + // Create a dummy node (which is not added to allnodes), that adds + // a reference to the root node, preventing it from being deleted, + // and tracking any changes of the root. + HandleSDNode Dummy(CurDAG->getRoot()); + SelectionDAG::allnodes_iterator ISelPosition (CurDAG->getRoot().getNode()); + ++ISelPosition; + + // Make sure that ISelPosition gets properly updated when nodes are deleted + // in calls made from this function. + ISelUpdater ISU(*CurDAG, ISelPosition); + + // The AllNodes list is now topological-sorted. Visit the + // nodes by starting at the end of the list (the root of the + // graph) and preceding back toward the beginning (the entry + // node). + while (ISelPosition != CurDAG->allnodes_begin()) { + SDNode *Node = &*--ISelPosition; + // Skip dead nodes. DAGCombiner is expected to eliminate all dead nodes, + // but there are currently some corner cases that it misses. Also, this + // makes it theoretically possible to disable the DAGCombiner. + if (Node->use_empty()) + continue; + +#ifndef NDEBUG + SmallVector Nodes; + Nodes.push_back(Node); + + while (!Nodes.empty()) { + auto N = Nodes.pop_back_val(); + if (N->getOpcode() == ISD::TokenFactor || N->getNodeId() < 0) + continue; + for (const SDValue &Op : N->op_values()) { + if (Op->getOpcode() == ISD::TokenFactor) + Nodes.push_back(Op.getNode()); + else { + // We rely on topological ordering of node ids for checking for + // cycles when fusing nodes during selection. All unselected nodes + // successors of an already selected node should have a negative id. + // This assertion will catch such cases. If this assertion triggers + // it is likely you using DAG-level Value/Node replacement functions + // (versus equivalent ISEL replacement) in backend-specific + // selections. See comment in EnforceNodeIdInvariant for more + // details. + assert(Op->getNodeId() != -1 && + "Node has already selected predecessor node"); + } + } + } +#endif + + // When we are using non-default rounding modes or FP exception behavior + // FP operations are represented by StrictFP pseudo-operations. For + // targets that do not (yet) understand strict FP operations directly, + // we convert them to normal FP opcodes instead at this point. This + // will allow them to be handled by existing target-specific instruction + // selectors. + if (Node->isStrictFPOpcode() && + (TLI->getOperationAction(Node->getOpcode(), Node->getValueType(0)) + != TargetLowering::Legal)) + Node = CurDAG->mutateStrictFPToFP(Node); + + LLVM_DEBUG(dbgs() << "\nISEL: Starting selection on root node: "; + Node->dump(CurDAG)); + + Select(Node); + } + + CurDAG->setRoot(Dummy.getValue()); + } + + LLVM_DEBUG(dbgs() << "\n===== Instruction selection ends:\n"); + + PostprocessISelDAG(); +} + +static bool hasExceptionPointerOrCodeUser(const CatchPadInst *CPI) { + for (const User *U : CPI->users()) { + if (const IntrinsicInst *EHPtrCall = dyn_cast(U)) { + Intrinsic::ID IID = EHPtrCall->getIntrinsicID(); + if (IID == Intrinsic::eh_exceptionpointer || + IID == Intrinsic::eh_exceptioncode) + return true; + } + } + return false; +} + +// wasm.landingpad.index intrinsic is for associating a landing pad index number +// with a catchpad instruction. Retrieve the landing pad index in the intrinsic +// and store the mapping in the function. +static void mapWasmLandingPadIndex(MachineBasicBlock *MBB, + const CatchPadInst *CPI) { + MachineFunction *MF = MBB->getParent(); + // In case of single catch (...), we don't emit LSDA, so we don't need + // this information. + bool IsSingleCatchAllClause = + CPI->getNumArgOperands() == 1 && + cast(CPI->getArgOperand(0))->isNullValue(); + if (!IsSingleCatchAllClause) { + // Create a mapping from landing pad label to landing pad index. + bool IntrFound = false; + for (const User *U : CPI->users()) { + if (const auto *Call = dyn_cast(U)) { + Intrinsic::ID IID = Call->getIntrinsicID(); + if (IID == Intrinsic::wasm_landingpad_index) { + Value *IndexArg = Call->getArgOperand(1); + int Index = cast(IndexArg)->getZExtValue(); + MF->setWasmLandingPadIndex(MBB, Index); + IntrFound = true; + break; + } + } + } + assert(IntrFound && "wasm.landingpad.index intrinsic not found!"); + (void)IntrFound; + } +} + +/// PrepareEHLandingPad - Emit an EH_LABEL, set up live-in registers, and +/// do other setup for EH landing-pad blocks. +bool SelectionDAGISel::PrepareEHLandingPad() { + MachineBasicBlock *MBB = FuncInfo->MBB; + const Constant *PersonalityFn = FuncInfo->Fn->getPersonalityFn(); + const BasicBlock *LLVMBB = MBB->getBasicBlock(); + const TargetRegisterClass *PtrRC = + TLI->getRegClassFor(TLI->getPointerTy(CurDAG->getDataLayout())); + + auto Pers = classifyEHPersonality(PersonalityFn); + + // Catchpads have one live-in register, which typically holds the exception + // pointer or code. + if (isFuncletEHPersonality(Pers)) { + if (const auto *CPI = dyn_cast(LLVMBB->getFirstNonPHI())) { + if (hasExceptionPointerOrCodeUser(CPI)) { + // Get or create the virtual register to hold the pointer or code. Mark + // the live in physreg and copy into the vreg. + MCPhysReg EHPhysReg = TLI->getExceptionPointerRegister(PersonalityFn); + assert(EHPhysReg && "target lacks exception pointer register"); + MBB->addLiveIn(EHPhysReg); + unsigned VReg = FuncInfo->getCatchPadExceptionPointerVReg(CPI, PtrRC); + BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(), + TII->get(TargetOpcode::COPY), VReg) + .addReg(EHPhysReg, RegState::Kill); + } + } + return true; + } + + // Add a label to mark the beginning of the landing pad. Deletion of the + // landing pad can thus be detected via the MachineModuleInfo. + MCSymbol *Label = MF->addLandingPad(MBB); + + const MCInstrDesc &II = TII->get(TargetOpcode::EH_LABEL); + BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(), II) + .addSym(Label); + + if (Pers == EHPersonality::Wasm_CXX) { + if (const auto *CPI = dyn_cast(LLVMBB->getFirstNonPHI())) + mapWasmLandingPadIndex(MBB, CPI); + } else { + // Assign the call site to the landing pad's begin label. + MF->setCallSiteLandingPad(Label, SDB->LPadToCallSiteMap[MBB]); + // Mark exception register as live in. + if (unsigned Reg = TLI->getExceptionPointerRegister(PersonalityFn)) + FuncInfo->ExceptionPointerVirtReg = MBB->addLiveIn(Reg, PtrRC); + // Mark exception selector register as live in. + if (unsigned Reg = TLI->getExceptionSelectorRegister(PersonalityFn)) + FuncInfo->ExceptionSelectorVirtReg = MBB->addLiveIn(Reg, PtrRC); + } + + return true; +} + +/// isFoldedOrDeadInstruction - Return true if the specified instruction is +/// side-effect free and is either dead or folded into a generated instruction. +/// Return false if it needs to be emitted. +static bool isFoldedOrDeadInstruction(const Instruction *I, + FunctionLoweringInfo *FuncInfo) { + return !I->mayWriteToMemory() && // Side-effecting instructions aren't folded. + !I->isTerminator() && // Terminators aren't folded. + !isa(I) && // Debug instructions aren't folded. + !I->isEHPad() && // EH pad instructions aren't folded. + !FuncInfo->isExportedInst(I); // Exported instrs must be computed. +} + +/// Collect llvm.dbg.declare information. This is done after argument lowering +/// in case the declarations refer to arguments. +static void processDbgDeclares(FunctionLoweringInfo *FuncInfo) { + MachineFunction *MF = FuncInfo->MF; + const DataLayout &DL = MF->getDataLayout(); + for (const BasicBlock &BB : *FuncInfo->Fn) { + for (const Instruction &I : BB) { + const DbgDeclareInst *DI = dyn_cast(&I); + if (!DI) + continue; + + assert(DI->getVariable() && "Missing variable"); + assert(DI->getDebugLoc() && "Missing location"); + const Value *Address = DI->getAddress(); + if (!Address) + continue; + + // Look through casts and constant offset GEPs. These mostly come from + // inalloca. + APInt Offset(DL.getTypeSizeInBits(Address->getType()), 0); + Address = Address->stripAndAccumulateInBoundsConstantOffsets(DL, Offset); + + // Check if the variable is a static alloca or a byval or inalloca + // argument passed in memory. If it is not, then we will ignore this + // intrinsic and handle this during isel like dbg.value. + int FI = std::numeric_limits::max(); + if (const auto *AI = dyn_cast(Address)) { + auto SI = FuncInfo->StaticAllocaMap.find(AI); + if (SI != FuncInfo->StaticAllocaMap.end()) + FI = SI->second; + } else if (const auto *Arg = dyn_cast(Address)) + FI = FuncInfo->getArgumentFrameIndex(Arg); + + if (FI == std::numeric_limits::max()) + continue; + + DIExpression *Expr = DI->getExpression(); + if (Offset.getBoolValue()) + Expr = DIExpression::prepend(Expr, DIExpression::ApplyOffset, + Offset.getZExtValue()); + MF->setVariableDbgInfo(DI->getVariable(), Expr, FI, DI->getDebugLoc()); + } + } +} + +void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) { + FastISelFailed = false; + // Initialize the Fast-ISel state, if needed. + FastISel *FastIS = nullptr; + if (TM.Options.EnableFastISel) { + LLVM_DEBUG(dbgs() << "Enabling fast-isel\n"); + FastIS = TLI->createFastISel(*FuncInfo, LibInfo); + } + + ReversePostOrderTraversal RPOT(&Fn); + + // Lower arguments up front. An RPO iteration always visits the entry block + // first. + assert(*RPOT.begin() == &Fn.getEntryBlock()); + ++NumEntryBlocks; + + // Set up FuncInfo for ISel. Entry blocks never have PHIs. + FuncInfo->MBB = FuncInfo->MBBMap[&Fn.getEntryBlock()]; + FuncInfo->InsertPt = FuncInfo->MBB->begin(); + + CurDAG->setFunctionLoweringInfo(FuncInfo); + + if (!FastIS) { + LowerArguments(Fn); + } else { + // See if fast isel can lower the arguments. + FastIS->startNewBlock(); + if (!FastIS->lowerArguments()) { + FastISelFailed = true; + // Fast isel failed to lower these arguments + ++NumFastIselFailLowerArguments; + + OptimizationRemarkMissed R("sdagisel", "FastISelFailure", + Fn.getSubprogram(), + &Fn.getEntryBlock()); + R << "FastISel didn't lower all arguments: " + << ore::NV("Prototype", Fn.getType()); + reportFastISelFailure(*MF, *ORE, R, EnableFastISelAbort > 1); + + // Use SelectionDAG argument lowering + LowerArguments(Fn); + CurDAG->setRoot(SDB->getControlRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + } + + // If we inserted any instructions at the beginning, make a note of + // where they are, so we can be sure to emit subsequent instructions + // after them. + if (FuncInfo->InsertPt != FuncInfo->MBB->begin()) + FastIS->setLastLocalValue(&*std::prev(FuncInfo->InsertPt)); + else + FastIS->setLastLocalValue(nullptr); + } + + bool Inserted = SwiftError->createEntriesInEntryBlock(SDB->getCurDebugLoc()); + + if (FastIS && Inserted) + FastIS->setLastLocalValue(&*std::prev(FuncInfo->InsertPt)); + + processDbgDeclares(FuncInfo); + + // Iterate over all basic blocks in the function. + StackProtector &SP = getAnalysis(); + for (const BasicBlock *LLVMBB : RPOT) { + if (OptLevel != CodeGenOpt::None) { + bool AllPredsVisited = true; + for (const_pred_iterator PI = pred_begin(LLVMBB), PE = pred_end(LLVMBB); + PI != PE; ++PI) { + if (!FuncInfo->VisitedBBs.count(*PI)) { + AllPredsVisited = false; + break; + } + } + + if (AllPredsVisited) { + for (const PHINode &PN : LLVMBB->phis()) + FuncInfo->ComputePHILiveOutRegInfo(&PN); + } else { + for (const PHINode &PN : LLVMBB->phis()) + FuncInfo->InvalidatePHILiveOutRegInfo(&PN); + } + + FuncInfo->VisitedBBs.insert(LLVMBB); + } + + BasicBlock::const_iterator const Begin = + LLVMBB->getFirstNonPHI()->getIterator(); + BasicBlock::const_iterator const End = LLVMBB->end(); + BasicBlock::const_iterator BI = End; + + FuncInfo->MBB = FuncInfo->MBBMap[LLVMBB]; + if (!FuncInfo->MBB) + continue; // Some blocks like catchpads have no code or MBB. + + // Insert new instructions after any phi or argument setup code. + FuncInfo->InsertPt = FuncInfo->MBB->end(); + + // Setup an EH landing-pad block. + FuncInfo->ExceptionPointerVirtReg = 0; + FuncInfo->ExceptionSelectorVirtReg = 0; + if (LLVMBB->isEHPad()) + if (!PrepareEHLandingPad()) + continue; + + // Before doing SelectionDAG ISel, see if FastISel has been requested. + if (FastIS) { + if (LLVMBB != &Fn.getEntryBlock()) + FastIS->startNewBlock(); + + unsigned NumFastIselRemaining = std::distance(Begin, End); + + // Pre-assign swifterror vregs. + SwiftError->preassignVRegs(FuncInfo->MBB, Begin, End); + + // Do FastISel on as many instructions as possible. + for (; BI != Begin; --BI) { + const Instruction *Inst = &*std::prev(BI); + + // If we no longer require this instruction, skip it. + if (isFoldedOrDeadInstruction(Inst, FuncInfo) || + ElidedArgCopyInstrs.count(Inst)) { + --NumFastIselRemaining; + continue; + } + + // Bottom-up: reset the insert pos at the top, after any local-value + // instructions. + FastIS->recomputeInsertPt(); + + // Try to select the instruction with FastISel. + if (FastIS->selectInstruction(Inst)) { + --NumFastIselRemaining; + ++NumFastIselSuccess; + // If fast isel succeeded, skip over all the folded instructions, and + // then see if there is a load right before the selected instructions. + // Try to fold the load if so. + const Instruction *BeforeInst = Inst; + while (BeforeInst != &*Begin) { + BeforeInst = &*std::prev(BasicBlock::const_iterator(BeforeInst)); + if (isa(BeforeInst)) + continue; + if (!isFoldedOrDeadInstruction(BeforeInst, FuncInfo)) + break; + } + if (BeforeInst != Inst && isa(BeforeInst) && + BeforeInst->hasOneUse() && + FastIS->tryToFoldLoad(cast(BeforeInst), Inst)) { + // If we succeeded, don't re-select the load. + BI = std::next(BasicBlock::const_iterator(BeforeInst)); + --NumFastIselRemaining; + ++NumFastIselSuccess; + } + continue; + } + + FastISelFailed = true; + + // Then handle certain instructions as single-LLVM-Instruction blocks. + // We cannot separate out GCrelocates to their own blocks since we need + // to keep track of gc-relocates for a particular gc-statepoint. This is + // done by SelectionDAGBuilder::LowerAsSTATEPOINT, called before + // visitGCRelocate. + if (isa(Inst) && !isStatepoint(Inst) && !isGCRelocate(Inst) && + !isGCResult(Inst)) { + OptimizationRemarkMissed R("sdagisel", "FastISelFailure", + Inst->getDebugLoc(), LLVMBB); + + R << "FastISel missed call"; + + if (R.isEnabled() || EnableFastISelAbort) { + std::string InstStrStorage; + raw_string_ostream InstStr(InstStrStorage); + InstStr << *Inst; + + R << ": " << InstStr.str(); + } + + reportFastISelFailure(*MF, *ORE, R, EnableFastISelAbort > 2); + + if (!Inst->getType()->isVoidTy() && !Inst->getType()->isTokenTy() && + !Inst->use_empty()) { + unsigned &R = FuncInfo->ValueMap[Inst]; + if (!R) + R = FuncInfo->CreateRegs(Inst); + } + + bool HadTailCall = false; + MachineBasicBlock::iterator SavedInsertPt = FuncInfo->InsertPt; + SelectBasicBlock(Inst->getIterator(), BI, HadTailCall); + + // If the call was emitted as a tail call, we're done with the block. + // We also need to delete any previously emitted instructions. + if (HadTailCall) { + FastIS->removeDeadCode(SavedInsertPt, FuncInfo->MBB->end()); + --BI; + break; + } + + // Recompute NumFastIselRemaining as Selection DAG instruction + // selection may have handled the call, input args, etc. + unsigned RemainingNow = std::distance(Begin, BI); + NumFastIselFailures += NumFastIselRemaining - RemainingNow; + NumFastIselRemaining = RemainingNow; + continue; + } + + OptimizationRemarkMissed R("sdagisel", "FastISelFailure", + Inst->getDebugLoc(), LLVMBB); + + bool ShouldAbort = EnableFastISelAbort; + if (Inst->isTerminator()) { + // Use a different message for terminator misses. + R << "FastISel missed terminator"; + // Don't abort for terminator unless the level is really high + ShouldAbort = (EnableFastISelAbort > 2); + } else { + R << "FastISel missed"; + } + + if (R.isEnabled() || EnableFastISelAbort) { + std::string InstStrStorage; + raw_string_ostream InstStr(InstStrStorage); + InstStr << *Inst; + R << ": " << InstStr.str(); + } + + reportFastISelFailure(*MF, *ORE, R, ShouldAbort); + + NumFastIselFailures += NumFastIselRemaining; + break; + } + + FastIS->recomputeInsertPt(); + } + + if (SP.shouldEmitSDCheck(*LLVMBB)) { + bool FunctionBasedInstrumentation = + TLI->getSSPStackGuardCheck(*Fn.getParent()); + SDB->SPDescriptor.initialize(LLVMBB, FuncInfo->MBBMap[LLVMBB], + FunctionBasedInstrumentation); + } + + if (Begin != BI) + ++NumDAGBlocks; + else + ++NumFastIselBlocks; + + if (Begin != BI) { + // Run SelectionDAG instruction selection on the remainder of the block + // not handled by FastISel. If FastISel is not run, this is the entire + // block. + bool HadTailCall; + SelectBasicBlock(Begin, BI, HadTailCall); + + // But if FastISel was run, we already selected some of the block. + // If we emitted a tail-call, we need to delete any previously emitted + // instruction that follows it. + if (FastIS && HadTailCall && FuncInfo->InsertPt != FuncInfo->MBB->end()) + FastIS->removeDeadCode(FuncInfo->InsertPt, FuncInfo->MBB->end()); + } + + if (FastIS) + FastIS->finishBasicBlock(); + FinishBasicBlock(); + FuncInfo->PHINodesToUpdate.clear(); + ElidedArgCopyInstrs.clear(); + } + + SP.copyToMachineFrameInfo(MF->getFrameInfo()); + + SwiftError->propagateVRegs(); + + delete FastIS; + SDB->clearDanglingDebugInfo(); + SDB->SPDescriptor.resetPerFunctionState(); +} + +/// Given that the input MI is before a partial terminator sequence TSeq, return +/// true if M + TSeq also a partial terminator sequence. +/// +/// A Terminator sequence is a sequence of MachineInstrs which at this point in +/// lowering copy vregs into physical registers, which are then passed into +/// terminator instructors so we can satisfy ABI constraints. A partial +/// terminator sequence is an improper subset of a terminator sequence (i.e. it +/// may be the whole terminator sequence). +static bool MIIsInTerminatorSequence(const MachineInstr &MI) { + // If we do not have a copy or an implicit def, we return true if and only if + // MI is a debug value. + if (!MI.isCopy() && !MI.isImplicitDef()) + // Sometimes DBG_VALUE MI sneak in between the copies from the vregs to the + // physical registers if there is debug info associated with the terminator + // of our mbb. We want to include said debug info in our terminator + // sequence, so we return true in that case. + return MI.isDebugValue(); + + // We have left the terminator sequence if we are not doing one of the + // following: + // + // 1. Copying a vreg into a physical register. + // 2. Copying a vreg into a vreg. + // 3. Defining a register via an implicit def. + + // OPI should always be a register definition... + MachineInstr::const_mop_iterator OPI = MI.operands_begin(); + if (!OPI->isReg() || !OPI->isDef()) + return false; + + // Defining any register via an implicit def is always ok. + if (MI.isImplicitDef()) + return true; + + // Grab the copy source... + MachineInstr::const_mop_iterator OPI2 = OPI; + ++OPI2; + assert(OPI2 != MI.operands_end() + && "Should have a copy implying we should have 2 arguments."); + + // Make sure that the copy dest is not a vreg when the copy source is a + // physical register. + if (!OPI2->isReg() || (!Register::isPhysicalRegister(OPI->getReg()) && + Register::isPhysicalRegister(OPI2->getReg()))) + return false; + + return true; +} + +/// Find the split point at which to splice the end of BB into its success stack +/// protector check machine basic block. +/// +/// On many platforms, due to ABI constraints, terminators, even before register +/// allocation, use physical registers. This creates an issue for us since +/// physical registers at this point can not travel across basic +/// blocks. Luckily, selectiondag always moves physical registers into vregs +/// when they enter functions and moves them through a sequence of copies back +/// into the physical registers right before the terminator creating a +/// ``Terminator Sequence''. This function is searching for the beginning of the +/// terminator sequence so that we can ensure that we splice off not just the +/// terminator, but additionally the copies that move the vregs into the +/// physical registers. +static MachineBasicBlock::iterator +FindSplitPointForStackProtector(MachineBasicBlock *BB) { + MachineBasicBlock::iterator SplitPoint = BB->getFirstTerminator(); + // + if (SplitPoint == BB->begin()) + return SplitPoint; + + MachineBasicBlock::iterator Start = BB->begin(); + MachineBasicBlock::iterator Previous = SplitPoint; + --Previous; + + while (MIIsInTerminatorSequence(*Previous)) { + SplitPoint = Previous; + if (Previous == Start) + break; + --Previous; + } + + return SplitPoint; +} + +void +SelectionDAGISel::FinishBasicBlock() { + LLVM_DEBUG(dbgs() << "Total amount of phi nodes to update: " + << FuncInfo->PHINodesToUpdate.size() << "\n"; + for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; + ++i) dbgs() + << "Node " << i << " : (" << FuncInfo->PHINodesToUpdate[i].first + << ", " << FuncInfo->PHINodesToUpdate[i].second << ")\n"); + + // Next, now that we know what the last MBB the LLVM BB expanded is, update + // PHI nodes in successors. + for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i) { + MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[i].first); + assert(PHI->isPHI() && + "This is not a machine PHI node that we are updating!"); + if (!FuncInfo->MBB->isSuccessor(PHI->getParent())) + continue; + PHI.addReg(FuncInfo->PHINodesToUpdate[i].second).addMBB(FuncInfo->MBB); + } + + // Handle stack protector. + if (SDB->SPDescriptor.shouldEmitFunctionBasedCheckStackProtector()) { + // The target provides a guard check function. There is no need to + // generate error handling code or to split current basic block. + MachineBasicBlock *ParentMBB = SDB->SPDescriptor.getParentMBB(); + + // Add load and check to the basicblock. + FuncInfo->MBB = ParentMBB; + FuncInfo->InsertPt = + FindSplitPointForStackProtector(ParentMBB); + SDB->visitSPDescriptorParent(SDB->SPDescriptor, ParentMBB); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + + // Clear the Per-BB State. + SDB->SPDescriptor.resetPerBBState(); + } else if (SDB->SPDescriptor.shouldEmitStackProtector()) { + MachineBasicBlock *ParentMBB = SDB->SPDescriptor.getParentMBB(); + MachineBasicBlock *SuccessMBB = SDB->SPDescriptor.getSuccessMBB(); + + // Find the split point to split the parent mbb. At the same time copy all + // physical registers used in the tail of parent mbb into virtual registers + // before the split point and back into physical registers after the split + // point. This prevents us needing to deal with Live-ins and many other + // register allocation issues caused by us splitting the parent mbb. The + // register allocator will clean up said virtual copies later on. + MachineBasicBlock::iterator SplitPoint = + FindSplitPointForStackProtector(ParentMBB); + + // Splice the terminator of ParentMBB into SuccessMBB. + SuccessMBB->splice(SuccessMBB->end(), ParentMBB, + SplitPoint, + ParentMBB->end()); + + // Add compare/jump on neq/jump to the parent BB. + FuncInfo->MBB = ParentMBB; + FuncInfo->InsertPt = ParentMBB->end(); + SDB->visitSPDescriptorParent(SDB->SPDescriptor, ParentMBB); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + + // CodeGen Failure MBB if we have not codegened it yet. + MachineBasicBlock *FailureMBB = SDB->SPDescriptor.getFailureMBB(); + if (FailureMBB->empty()) { + FuncInfo->MBB = FailureMBB; + FuncInfo->InsertPt = FailureMBB->end(); + SDB->visitSPDescriptorFailure(SDB->SPDescriptor); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + } + + // Clear the Per-BB State. + SDB->SPDescriptor.resetPerBBState(); + } + + // Lower each BitTestBlock. + for (auto &BTB : SDB->SL->BitTestCases) { + // Lower header first, if it wasn't already lowered + if (!BTB.Emitted) { + // Set the current basic block to the mbb we wish to insert the code into + FuncInfo->MBB = BTB.Parent; + FuncInfo->InsertPt = FuncInfo->MBB->end(); + // Emit the code + SDB->visitBitTestHeader(BTB, FuncInfo->MBB); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + } + + BranchProbability UnhandledProb = BTB.Prob; + for (unsigned j = 0, ej = BTB.Cases.size(); j != ej; ++j) { + UnhandledProb -= BTB.Cases[j].ExtraProb; + // Set the current basic block to the mbb we wish to insert the code into + FuncInfo->MBB = BTB.Cases[j].ThisBB; + FuncInfo->InsertPt = FuncInfo->MBB->end(); + // Emit the code + + // If all cases cover a contiguous range, it is not necessary to jump to + // the default block after the last bit test fails. This is because the + // range check during bit test header creation has guaranteed that every + // case here doesn't go outside the range. In this case, there is no need + // to perform the last bit test, as it will always be true. Instead, make + // the second-to-last bit-test fall through to the target of the last bit + // test, and delete the last bit test. + + MachineBasicBlock *NextMBB; + if (BTB.ContiguousRange && j + 2 == ej) { + // Second-to-last bit-test with contiguous range: fall through to the + // target of the final bit test. + NextMBB = BTB.Cases[j + 1].TargetBB; + } else if (j + 1 == ej) { + // For the last bit test, fall through to Default. + NextMBB = BTB.Default; + } else { + // Otherwise, fall through to the next bit test. + NextMBB = BTB.Cases[j + 1].ThisBB; + } + + SDB->visitBitTestCase(BTB, NextMBB, UnhandledProb, BTB.Reg, BTB.Cases[j], + FuncInfo->MBB); + + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + + if (BTB.ContiguousRange && j + 2 == ej) { + // Since we're not going to use the final bit test, remove it. + BTB.Cases.pop_back(); + break; + } + } + + // Update PHI Nodes + for (unsigned pi = 0, pe = FuncInfo->PHINodesToUpdate.size(); + pi != pe; ++pi) { + MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[pi].first); + MachineBasicBlock *PHIBB = PHI->getParent(); + assert(PHI->isPHI() && + "This is not a machine PHI node that we are updating!"); + // This is "default" BB. We have two jumps to it. From "header" BB and + // from last "case" BB, unless the latter was skipped. + if (PHIBB == BTB.Default) { + PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second).addMBB(BTB.Parent); + if (!BTB.ContiguousRange) { + PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second) + .addMBB(BTB.Cases.back().ThisBB); + } + } + // One of "cases" BB. + for (unsigned j = 0, ej = BTB.Cases.size(); + j != ej; ++j) { + MachineBasicBlock* cBB = BTB.Cases[j].ThisBB; + if (cBB->isSuccessor(PHIBB)) + PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second).addMBB(cBB); + } + } + } + SDB->SL->BitTestCases.clear(); + + // If the JumpTable record is filled in, then we need to emit a jump table. + // Updating the PHI nodes is tricky in this case, since we need to determine + // whether the PHI is a successor of the range check MBB or the jump table MBB + for (unsigned i = 0, e = SDB->SL->JTCases.size(); i != e; ++i) { + // Lower header first, if it wasn't already lowered + if (!SDB->SL->JTCases[i].first.Emitted) { + // Set the current basic block to the mbb we wish to insert the code into + FuncInfo->MBB = SDB->SL->JTCases[i].first.HeaderBB; + FuncInfo->InsertPt = FuncInfo->MBB->end(); + // Emit the code + SDB->visitJumpTableHeader(SDB->SL->JTCases[i].second, + SDB->SL->JTCases[i].first, FuncInfo->MBB); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + } + + // Set the current basic block to the mbb we wish to insert the code into + FuncInfo->MBB = SDB->SL->JTCases[i].second.MBB; + FuncInfo->InsertPt = FuncInfo->MBB->end(); + // Emit the code + SDB->visitJumpTable(SDB->SL->JTCases[i].second); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + + // Update PHI Nodes + for (unsigned pi = 0, pe = FuncInfo->PHINodesToUpdate.size(); + pi != pe; ++pi) { + MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[pi].first); + MachineBasicBlock *PHIBB = PHI->getParent(); + assert(PHI->isPHI() && + "This is not a machine PHI node that we are updating!"); + // "default" BB. We can go there only from header BB. + if (PHIBB == SDB->SL->JTCases[i].second.Default) + PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second) + .addMBB(SDB->SL->JTCases[i].first.HeaderBB); + // JT BB. Just iterate over successors here + if (FuncInfo->MBB->isSuccessor(PHIBB)) + PHI.addReg(FuncInfo->PHINodesToUpdate[pi].second).addMBB(FuncInfo->MBB); + } + } + SDB->SL->JTCases.clear(); + + // If we generated any switch lowering information, build and codegen any + // additional DAGs necessary. + for (unsigned i = 0, e = SDB->SL->SwitchCases.size(); i != e; ++i) { + // Set the current basic block to the mbb we wish to insert the code into + FuncInfo->MBB = SDB->SL->SwitchCases[i].ThisBB; + FuncInfo->InsertPt = FuncInfo->MBB->end(); + + // Determine the unique successors. + SmallVector Succs; + Succs.push_back(SDB->SL->SwitchCases[i].TrueBB); + if (SDB->SL->SwitchCases[i].TrueBB != SDB->SL->SwitchCases[i].FalseBB) + Succs.push_back(SDB->SL->SwitchCases[i].FalseBB); + + // Emit the code. Note that this could result in FuncInfo->MBB being split. + SDB->visitSwitchCase(SDB->SL->SwitchCases[i], FuncInfo->MBB); + CurDAG->setRoot(SDB->getRoot()); + SDB->clear(); + CodeGenAndEmitDAG(); + + // Remember the last block, now that any splitting is done, for use in + // populating PHI nodes in successors. + MachineBasicBlock *ThisBB = FuncInfo->MBB; + + // Handle any PHI nodes in successors of this chunk, as if we were coming + // from the original BB before switch expansion. Note that PHI nodes can + // occur multiple times in PHINodesToUpdate. We have to be very careful to + // handle them the right number of times. + for (unsigned i = 0, e = Succs.size(); i != e; ++i) { + FuncInfo->MBB = Succs[i]; + FuncInfo->InsertPt = FuncInfo->MBB->end(); + // FuncInfo->MBB may have been removed from the CFG if a branch was + // constant folded. + if (ThisBB->isSuccessor(FuncInfo->MBB)) { + for (MachineBasicBlock::iterator + MBBI = FuncInfo->MBB->begin(), MBBE = FuncInfo->MBB->end(); + MBBI != MBBE && MBBI->isPHI(); ++MBBI) { + MachineInstrBuilder PHI(*MF, MBBI); + // This value for this PHI node is recorded in PHINodesToUpdate. + for (unsigned pn = 0; ; ++pn) { + assert(pn != FuncInfo->PHINodesToUpdate.size() && + "Didn't find PHI entry!"); + if (FuncInfo->PHINodesToUpdate[pn].first == PHI) { + PHI.addReg(FuncInfo->PHINodesToUpdate[pn].second).addMBB(ThisBB); + break; + } + } + } + } + } + } + SDB->SL->SwitchCases.clear(); +} + +/// Create the scheduler. If a specific scheduler was specified +/// via the SchedulerRegistry, use it, otherwise select the +/// one preferred by the target. +/// +ScheduleDAGSDNodes *SelectionDAGISel::CreateScheduler() { + return ISHeuristic(this, OptLevel); +} + +//===----------------------------------------------------------------------===// +// Helper functions used by the generated instruction selector. +//===----------------------------------------------------------------------===// +// Calls to these methods are generated by tblgen. + +/// CheckAndMask - The isel is trying to match something like (and X, 255). If +/// the dag combiner simplified the 255, we still want to match. RHS is the +/// actual value in the DAG on the RHS of an AND, and DesiredMaskS is the value +/// specified in the .td file (e.g. 255). +bool SelectionDAGISel::CheckAndMask(SDValue LHS, ConstantSDNode *RHS, + int64_t DesiredMaskS) const { + const APInt &ActualMask = RHS->getAPIntValue(); + const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS); + + // If the actual mask exactly matches, success! + if (ActualMask == DesiredMask) + return true; + + // If the actual AND mask is allowing unallowed bits, this doesn't match. + if (!ActualMask.isSubsetOf(DesiredMask)) + return false; + + // Otherwise, the DAG Combiner may have proven that the value coming in is + // either already zero or is not demanded. Check for known zero input bits. + APInt NeededMask = DesiredMask & ~ActualMask; + if (CurDAG->MaskedValueIsZero(LHS, NeededMask)) + return true; + + // TODO: check to see if missing bits are just not demanded. + + // Otherwise, this pattern doesn't match. + return false; +} + +/// CheckOrMask - The isel is trying to match something like (or X, 255). If +/// the dag combiner simplified the 255, we still want to match. RHS is the +/// actual value in the DAG on the RHS of an OR, and DesiredMaskS is the value +/// specified in the .td file (e.g. 255). +bool SelectionDAGISel::CheckOrMask(SDValue LHS, ConstantSDNode *RHS, + int64_t DesiredMaskS) const { + const APInt &ActualMask = RHS->getAPIntValue(); + const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS); + + // If the actual mask exactly matches, success! + if (ActualMask == DesiredMask) + return true; + + // If the actual AND mask is allowing unallowed bits, this doesn't match. + if (!ActualMask.isSubsetOf(DesiredMask)) + return false; + + // Otherwise, the DAG Combiner may have proven that the value coming in is + // either already zero or is not demanded. Check for known zero input bits. + APInt NeededMask = DesiredMask & ~ActualMask; + KnownBits Known = CurDAG->computeKnownBits(LHS); + + // If all the missing bits in the or are already known to be set, match! + if (NeededMask.isSubsetOf(Known.One)) + return true; + + // TODO: check to see if missing bits are just not demanded. + + // Otherwise, this pattern doesn't match. + return false; +} + +/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated +/// by tblgen. Others should not call it. +void SelectionDAGISel::SelectInlineAsmMemoryOperands(std::vector &Ops, + const SDLoc &DL) { + std::vector InOps; + std::swap(InOps, Ops); + + Ops.push_back(InOps[InlineAsm::Op_InputChain]); // 0 + Ops.push_back(InOps[InlineAsm::Op_AsmString]); // 1 + Ops.push_back(InOps[InlineAsm::Op_MDNode]); // 2, !srcloc + Ops.push_back(InOps[InlineAsm::Op_ExtraInfo]); // 3 (SideEffect, AlignStack) + + unsigned i = InlineAsm::Op_FirstOperand, e = InOps.size(); + if (InOps[e-1].getValueType() == MVT::Glue) + --e; // Don't process a glue operand if it is here. + + while (i != e) { + unsigned Flags = cast(InOps[i])->getZExtValue(); + if (!InlineAsm::isMemKind(Flags)) { + // Just skip over this operand, copying the operands verbatim. + Ops.insert(Ops.end(), InOps.begin()+i, + InOps.begin()+i+InlineAsm::getNumOperandRegisters(Flags) + 1); + i += InlineAsm::getNumOperandRegisters(Flags) + 1; + } else { + assert(InlineAsm::getNumOperandRegisters(Flags) == 1 && + "Memory operand with multiple values?"); + + unsigned TiedToOperand; + if (InlineAsm::isUseOperandTiedToDef(Flags, TiedToOperand)) { + // We need the constraint ID from the operand this is tied to. + unsigned CurOp = InlineAsm::Op_FirstOperand; + Flags = cast(InOps[CurOp])->getZExtValue(); + for (; TiedToOperand; --TiedToOperand) { + CurOp += InlineAsm::getNumOperandRegisters(Flags)+1; + Flags = cast(InOps[CurOp])->getZExtValue(); + } + } + + // Otherwise, this is a memory operand. Ask the target to select it. + std::vector SelOps; + unsigned ConstraintID = InlineAsm::getMemoryConstraintID(Flags); + if (SelectInlineAsmMemoryOperand(InOps[i+1], ConstraintID, SelOps)) + report_fatal_error("Could not match memory address. Inline asm" + " failure!"); + + // Add this to the output node. + unsigned NewFlags = + InlineAsm::getFlagWord(InlineAsm::Kind_Mem, SelOps.size()); + NewFlags = InlineAsm::getFlagWordForMem(NewFlags, ConstraintID); + Ops.push_back(CurDAG->getTargetConstant(NewFlags, DL, MVT::i32)); + Ops.insert(Ops.end(), SelOps.begin(), SelOps.end()); + i += 2; + } + } + + // Add the glue input back if present. + if (e != InOps.size()) + Ops.push_back(InOps.back()); +} + +/// findGlueUse - Return use of MVT::Glue value produced by the specified +/// SDNode. +/// +static SDNode *findGlueUse(SDNode *N) { + unsigned FlagResNo = N->getNumValues()-1; + for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) { + SDUse &Use = I.getUse(); + if (Use.getResNo() == FlagResNo) + return Use.getUser(); + } + return nullptr; +} + +/// findNonImmUse - Return true if "Def" is a predecessor of "Root" via a path +/// beyond "ImmedUse". We may ignore chains as they are checked separately. +static bool findNonImmUse(SDNode *Root, SDNode *Def, SDNode *ImmedUse, + bool IgnoreChains) { + SmallPtrSet Visited; + SmallVector WorkList; + // Only check if we have non-immediate uses of Def. + if (ImmedUse->isOnlyUserOf(Def)) + return false; + + // We don't care about paths to Def that go through ImmedUse so mark it + // visited and mark non-def operands as used. + Visited.insert(ImmedUse); + for (const SDValue &Op : ImmedUse->op_values()) { + SDNode *N = Op.getNode(); + // Ignore chain deps (they are validated by + // HandleMergeInputChains) and immediate uses + if ((Op.getValueType() == MVT::Other && IgnoreChains) || N == Def) + continue; + if (!Visited.insert(N).second) + continue; + WorkList.push_back(N); + } + + // Initialize worklist to operands of Root. + if (Root != ImmedUse) { + for (const SDValue &Op : Root->op_values()) { + SDNode *N = Op.getNode(); + // Ignore chains (they are validated by HandleMergeInputChains) + if ((Op.getValueType() == MVT::Other && IgnoreChains) || N == Def) + continue; + if (!Visited.insert(N).second) + continue; + WorkList.push_back(N); + } + } + + return SDNode::hasPredecessorHelper(Def, Visited, WorkList, 0, true); +} + +/// IsProfitableToFold - Returns true if it's profitable to fold the specific +/// operand node N of U during instruction selection that starts at Root. +bool SelectionDAGISel::IsProfitableToFold(SDValue N, SDNode *U, + SDNode *Root) const { + if (OptLevel == CodeGenOpt::None) return false; + return N.hasOneUse(); +} + +/// IsLegalToFold - Returns true if the specific operand node N of +/// U can be folded during instruction selection that starts at Root. +bool SelectionDAGISel::IsLegalToFold(SDValue N, SDNode *U, SDNode *Root, + CodeGenOpt::Level OptLevel, + bool IgnoreChains) { + if (OptLevel == CodeGenOpt::None) return false; + + // If Root use can somehow reach N through a path that that doesn't contain + // U then folding N would create a cycle. e.g. In the following + // diagram, Root can reach N through X. If N is folded into Root, then + // X is both a predecessor and a successor of U. + // + // [N*] // + // ^ ^ // + // / \ // + // [U*] [X]? // + // ^ ^ // + // \ / // + // \ / // + // [Root*] // + // + // * indicates nodes to be folded together. + // + // If Root produces glue, then it gets (even more) interesting. Since it + // will be "glued" together with its glue use in the scheduler, we need to + // check if it might reach N. + // + // [N*] // + // ^ ^ // + // / \ // + // [U*] [X]? // + // ^ ^ // + // \ \ // + // \ | // + // [Root*] | // + // ^ | // + // f | // + // | / // + // [Y] / // + // ^ / // + // f / // + // | / // + // [GU] // + // + // If GU (glue use) indirectly reaches N (the load), and Root folds N + // (call it Fold), then X is a predecessor of GU and a successor of + // Fold. But since Fold and GU are glued together, this will create + // a cycle in the scheduling graph. + + // If the node has glue, walk down the graph to the "lowest" node in the + // glueged set. + EVT VT = Root->getValueType(Root->getNumValues()-1); + while (VT == MVT::Glue) { + SDNode *GU = findGlueUse(Root); + if (!GU) + break; + Root = GU; + VT = Root->getValueType(Root->getNumValues()-1); + + // If our query node has a glue result with a use, we've walked up it. If + // the user (which has already been selected) has a chain or indirectly uses + // the chain, HandleMergeInputChains will not consider it. Because of + // this, we cannot ignore chains in this predicate. + IgnoreChains = false; + } + + return !findNonImmUse(Root, N.getNode(), U, IgnoreChains); +} + +void SelectionDAGISel::Select_INLINEASM(SDNode *N, bool Branch) { + SDLoc DL(N); + + std::vector Ops(N->op_begin(), N->op_end()); + SelectInlineAsmMemoryOperands(Ops, DL); + + const EVT VTs[] = {MVT::Other, MVT::Glue}; + SDValue New = CurDAG->getNode(Branch ? ISD::INLINEASM_BR : ISD::INLINEASM, DL, VTs, Ops); + New->setNodeId(-1); + ReplaceUses(N, New.getNode()); + CurDAG->RemoveDeadNode(N); +} + +void SelectionDAGISel::Select_READ_REGISTER(SDNode *Op) { + SDLoc dl(Op); + MDNodeSDNode *MD = dyn_cast(Op->getOperand(1)); + const MDString *RegStr = dyn_cast(MD->getMD()->getOperand(0)); + Register Reg = + TLI->getRegisterByName(RegStr->getString().data(), Op->getValueType(0), + CurDAG->getMachineFunction()); + SDValue New = CurDAG->getCopyFromReg( + Op->getOperand(0), dl, Reg, Op->getValueType(0)); + New->setNodeId(-1); + ReplaceUses(Op, New.getNode()); + CurDAG->RemoveDeadNode(Op); +} + +void SelectionDAGISel::Select_WRITE_REGISTER(SDNode *Op) { + SDLoc dl(Op); + MDNodeSDNode *MD = dyn_cast(Op->getOperand(1)); + const MDString *RegStr = dyn_cast(MD->getMD()->getOperand(0)); + Register Reg = TLI->getRegisterByName(RegStr->getString().data(), + Op->getOperand(2).getValueType(), + CurDAG->getMachineFunction()); + SDValue New = CurDAG->getCopyToReg( + Op->getOperand(0), dl, Reg, Op->getOperand(2)); + New->setNodeId(-1); + ReplaceUses(Op, New.getNode()); + CurDAG->RemoveDeadNode(Op); +} + +void SelectionDAGISel::Select_UNDEF(SDNode *N) { + CurDAG->SelectNodeTo(N, TargetOpcode::IMPLICIT_DEF, N->getValueType(0)); +} + +/// GetVBR - decode a vbr encoding whose top bit is set. +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline uint64_t +GetVBR(uint64_t Val, const unsigned char *MatcherTable, unsigned &Idx) { + assert(Val >= 128 && "Not a VBR"); + Val &= 127; // Remove first vbr bit. + + unsigned Shift = 7; + uint64_t NextBits; + do { + NextBits = MatcherTable[Idx++]; + Val |= (NextBits&127) << Shift; + Shift += 7; + } while (NextBits & 128); + + return Val; +} + +/// When a match is complete, this method updates uses of interior chain results +/// to use the new results. +void SelectionDAGISel::UpdateChains( + SDNode *NodeToMatch, SDValue InputChain, + SmallVectorImpl &ChainNodesMatched, bool isMorphNodeTo) { + SmallVector NowDeadNodes; + + // Now that all the normal results are replaced, we replace the chain and + // glue results if present. + if (!ChainNodesMatched.empty()) { + assert(InputChain.getNode() && + "Matched input chains but didn't produce a chain"); + // Loop over all of the nodes we matched that produced a chain result. + // Replace all the chain results with the final chain we ended up with. + for (unsigned i = 0, e = ChainNodesMatched.size(); i != e; ++i) { + SDNode *ChainNode = ChainNodesMatched[i]; + // If ChainNode is null, it's because we replaced it on a previous + // iteration and we cleared it out of the map. Just skip it. + if (!ChainNode) + continue; + + assert(ChainNode->getOpcode() != ISD::DELETED_NODE && + "Deleted node left in chain"); + + // Don't replace the results of the root node if we're doing a + // MorphNodeTo. + if (ChainNode == NodeToMatch && isMorphNodeTo) + continue; + + SDValue ChainVal = SDValue(ChainNode, ChainNode->getNumValues()-1); + if (ChainVal.getValueType() == MVT::Glue) + ChainVal = ChainVal.getValue(ChainVal->getNumValues()-2); + assert(ChainVal.getValueType() == MVT::Other && "Not a chain?"); + SelectionDAG::DAGNodeDeletedListener NDL( + *CurDAG, [&](SDNode *N, SDNode *E) { + std::replace(ChainNodesMatched.begin(), ChainNodesMatched.end(), N, + static_cast(nullptr)); + }); + if (ChainNode->getOpcode() != ISD::TokenFactor) + ReplaceUses(ChainVal, InputChain); + + // If the node became dead and we haven't already seen it, delete it. + if (ChainNode != NodeToMatch && ChainNode->use_empty() && + !std::count(NowDeadNodes.begin(), NowDeadNodes.end(), ChainNode)) + NowDeadNodes.push_back(ChainNode); + } + } + + if (!NowDeadNodes.empty()) + CurDAG->RemoveDeadNodes(NowDeadNodes); + + LLVM_DEBUG(dbgs() << "ISEL: Match complete!\n"); +} + +/// HandleMergeInputChains - This implements the OPC_EmitMergeInputChains +/// operation for when the pattern matched at least one node with a chains. The +/// input vector contains a list of all of the chained nodes that we match. We +/// must determine if this is a valid thing to cover (i.e. matching it won't +/// induce cycles in the DAG) and if so, creating a TokenFactor node. that will +/// be used as the input node chain for the generated nodes. +static SDValue +HandleMergeInputChains(SmallVectorImpl &ChainNodesMatched, + SelectionDAG *CurDAG) { + + SmallPtrSet Visited; + SmallVector Worklist; + SmallVector InputChains; + unsigned int Max = 8192; + + // Quick exit on trivial merge. + if (ChainNodesMatched.size() == 1) + return ChainNodesMatched[0]->getOperand(0); + + // Add chains that aren't already added (internal). Peek through + // token factors. + std::function AddChains = [&](const SDValue V) { + if (V.getValueType() != MVT::Other) + return; + if (V->getOpcode() == ISD::EntryToken) + return; + if (!Visited.insert(V.getNode()).second) + return; + if (V->getOpcode() == ISD::TokenFactor) { + for (const SDValue &Op : V->op_values()) + AddChains(Op); + } else + InputChains.push_back(V); + }; + + for (auto *N : ChainNodesMatched) { + Worklist.push_back(N); + Visited.insert(N); + } + + while (!Worklist.empty()) + AddChains(Worklist.pop_back_val()->getOperand(0)); + + // Skip the search if there are no chain dependencies. + if (InputChains.size() == 0) + return CurDAG->getEntryNode(); + + // If one of these chains is a successor of input, we must have a + // node that is both the predecessor and successor of the + // to-be-merged nodes. Fail. + Visited.clear(); + for (SDValue V : InputChains) + Worklist.push_back(V.getNode()); + + for (auto *N : ChainNodesMatched) + if (SDNode::hasPredecessorHelper(N, Visited, Worklist, Max, true)) + return SDValue(); + + // Return merged chain. + if (InputChains.size() == 1) + return InputChains[0]; + return CurDAG->getNode(ISD::TokenFactor, SDLoc(ChainNodesMatched[0]), + MVT::Other, InputChains); +} + +/// MorphNode - Handle morphing a node in place for the selector. +SDNode *SelectionDAGISel:: +MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTList, + ArrayRef Ops, unsigned EmitNodeInfo) { + // It is possible we're using MorphNodeTo to replace a node with no + // normal results with one that has a normal result (or we could be + // adding a chain) and the input could have glue and chains as well. + // In this case we need to shift the operands down. + // FIXME: This is a horrible hack and broken in obscure cases, no worse + // than the old isel though. + int OldGlueResultNo = -1, OldChainResultNo = -1; + + unsigned NTMNumResults = Node->getNumValues(); + if (Node->getValueType(NTMNumResults-1) == MVT::Glue) { + OldGlueResultNo = NTMNumResults-1; + if (NTMNumResults != 1 && + Node->getValueType(NTMNumResults-2) == MVT::Other) + OldChainResultNo = NTMNumResults-2; + } else if (Node->getValueType(NTMNumResults-1) == MVT::Other) + OldChainResultNo = NTMNumResults-1; + + // Call the underlying SelectionDAG routine to do the transmogrification. Note + // that this deletes operands of the old node that become dead. + SDNode *Res = CurDAG->MorphNodeTo(Node, ~TargetOpc, VTList, Ops); + + // MorphNodeTo can operate in two ways: if an existing node with the + // specified operands exists, it can just return it. Otherwise, it + // updates the node in place to have the requested operands. + if (Res == Node) { + // If we updated the node in place, reset the node ID. To the isel, + // this should be just like a newly allocated machine node. + Res->setNodeId(-1); + } + + unsigned ResNumResults = Res->getNumValues(); + // Move the glue if needed. + if ((EmitNodeInfo & OPFL_GlueOutput) && OldGlueResultNo != -1 && + (unsigned)OldGlueResultNo != ResNumResults-1) + ReplaceUses(SDValue(Node, OldGlueResultNo), + SDValue(Res, ResNumResults - 1)); + + if ((EmitNodeInfo & OPFL_GlueOutput) != 0) + --ResNumResults; + + // Move the chain reference if needed. + if ((EmitNodeInfo & OPFL_Chain) && OldChainResultNo != -1 && + (unsigned)OldChainResultNo != ResNumResults-1) + ReplaceUses(SDValue(Node, OldChainResultNo), + SDValue(Res, ResNumResults - 1)); + + // Otherwise, no replacement happened because the node already exists. Replace + // Uses of the old node with the new one. + if (Res != Node) { + ReplaceNode(Node, Res); + } else { + EnforceNodeIdInvariant(Res); + } + + return Res; +} + +/// CheckSame - Implements OP_CheckSame. +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckSame(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, + const SmallVectorImpl> &RecordedNodes) { + // Accept if it is exactly the same as a previously recorded node. + unsigned RecNo = MatcherTable[MatcherIndex++]; + assert(RecNo < RecordedNodes.size() && "Invalid CheckSame"); + return N == RecordedNodes[RecNo].first; +} + +/// CheckChildSame - Implements OP_CheckChildXSame. +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckChildSame(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, + const SmallVectorImpl> &RecordedNodes, + unsigned ChildNo) { + if (ChildNo >= N.getNumOperands()) + return false; // Match fails if out of range child #. + return ::CheckSame(MatcherTable, MatcherIndex, N.getOperand(ChildNo), + RecordedNodes); +} + +/// CheckPatternPredicate - Implements OP_CheckPatternPredicate. +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckPatternPredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex, + const SelectionDAGISel &SDISel) { + return SDISel.CheckPatternPredicate(MatcherTable[MatcherIndex++]); +} + +/// CheckNodePredicate - Implements OP_CheckNodePredicate. +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckNodePredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex, + const SelectionDAGISel &SDISel, SDNode *N) { + return SDISel.CheckNodePredicate(N, MatcherTable[MatcherIndex++]); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckOpcode(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDNode *N) { + uint16_t Opc = MatcherTable[MatcherIndex++]; + Opc |= (unsigned short)MatcherTable[MatcherIndex++] << 8; + return N->getOpcode() == Opc; +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckType(const unsigned char *MatcherTable, unsigned &MatcherIndex, SDValue N, + const TargetLowering *TLI, const DataLayout &DL) { + MVT::SimpleValueType VT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + if (N.getValueType() == VT) return true; + + // Handle the case when VT is iPTR. + return VT == MVT::iPTR && N.getValueType() == TLI->getPointerTy(DL); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckChildType(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, const TargetLowering *TLI, const DataLayout &DL, + unsigned ChildNo) { + if (ChildNo >= N.getNumOperands()) + return false; // Match fails if out of range child #. + return ::CheckType(MatcherTable, MatcherIndex, N.getOperand(ChildNo), TLI, + DL); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckCondCode(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N) { + return cast(N)->get() == + (ISD::CondCode)MatcherTable[MatcherIndex++]; +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckChild2CondCode(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N) { + if (2 >= N.getNumOperands()) + return false; + return ::CheckCondCode(MatcherTable, MatcherIndex, N.getOperand(2)); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckValueType(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, const TargetLowering *TLI, const DataLayout &DL) { + MVT::SimpleValueType VT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + if (cast(N)->getVT() == VT) + return true; + + // Handle the case when VT is iPTR. + return VT == MVT::iPTR && cast(N)->getVT() == TLI->getPointerTy(DL); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckInteger(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N) { + int64_t Val = MatcherTable[MatcherIndex++]; + if (Val & 128) + Val = GetVBR(Val, MatcherTable, MatcherIndex); + + ConstantSDNode *C = dyn_cast(N); + return C && C->getSExtValue() == Val; +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckChildInteger(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, unsigned ChildNo) { + if (ChildNo >= N.getNumOperands()) + return false; // Match fails if out of range child #. + return ::CheckInteger(MatcherTable, MatcherIndex, N.getOperand(ChildNo)); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckAndImm(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, const SelectionDAGISel &SDISel) { + int64_t Val = MatcherTable[MatcherIndex++]; + if (Val & 128) + Val = GetVBR(Val, MatcherTable, MatcherIndex); + + if (N->getOpcode() != ISD::AND) return false; + + ConstantSDNode *C = dyn_cast(N->getOperand(1)); + return C && SDISel.CheckAndMask(N.getOperand(0), C, Val); +} + +LLVM_ATTRIBUTE_ALWAYS_INLINE static inline bool +CheckOrImm(const unsigned char *MatcherTable, unsigned &MatcherIndex, + SDValue N, const SelectionDAGISel &SDISel) { + int64_t Val = MatcherTable[MatcherIndex++]; + if (Val & 128) + Val = GetVBR(Val, MatcherTable, MatcherIndex); + + if (N->getOpcode() != ISD::OR) return false; + + ConstantSDNode *C = dyn_cast(N->getOperand(1)); + return C && SDISel.CheckOrMask(N.getOperand(0), C, Val); +} + +/// IsPredicateKnownToFail - If we know how and can do so without pushing a +/// scope, evaluate the current node. If the current predicate is known to +/// fail, set Result=true and return anything. If the current predicate is +/// known to pass, set Result=false and return the MatcherIndex to continue +/// with. If the current predicate is unknown, set Result=false and return the +/// MatcherIndex to continue with. +static unsigned IsPredicateKnownToFail(const unsigned char *Table, + unsigned Index, SDValue N, + bool &Result, + const SelectionDAGISel &SDISel, + SmallVectorImpl> &RecordedNodes) { + switch (Table[Index++]) { + default: + Result = false; + return Index-1; // Could not evaluate this predicate. + case SelectionDAGISel::OPC_CheckSame: + Result = !::CheckSame(Table, Index, N, RecordedNodes); + return Index; + case SelectionDAGISel::OPC_CheckChild0Same: + case SelectionDAGISel::OPC_CheckChild1Same: + case SelectionDAGISel::OPC_CheckChild2Same: + case SelectionDAGISel::OPC_CheckChild3Same: + Result = !::CheckChildSame(Table, Index, N, RecordedNodes, + Table[Index-1] - SelectionDAGISel::OPC_CheckChild0Same); + return Index; + case SelectionDAGISel::OPC_CheckPatternPredicate: + Result = !::CheckPatternPredicate(Table, Index, SDISel); + return Index; + case SelectionDAGISel::OPC_CheckPredicate: + Result = !::CheckNodePredicate(Table, Index, SDISel, N.getNode()); + return Index; + case SelectionDAGISel::OPC_CheckOpcode: + Result = !::CheckOpcode(Table, Index, N.getNode()); + return Index; + case SelectionDAGISel::OPC_CheckType: + Result = !::CheckType(Table, Index, N, SDISel.TLI, + SDISel.CurDAG->getDataLayout()); + return Index; + case SelectionDAGISel::OPC_CheckTypeRes: { + unsigned Res = Table[Index++]; + Result = !::CheckType(Table, Index, N.getValue(Res), SDISel.TLI, + SDISel.CurDAG->getDataLayout()); + return Index; + } + case SelectionDAGISel::OPC_CheckChild0Type: + case SelectionDAGISel::OPC_CheckChild1Type: + case SelectionDAGISel::OPC_CheckChild2Type: + case SelectionDAGISel::OPC_CheckChild3Type: + case SelectionDAGISel::OPC_CheckChild4Type: + case SelectionDAGISel::OPC_CheckChild5Type: + case SelectionDAGISel::OPC_CheckChild6Type: + case SelectionDAGISel::OPC_CheckChild7Type: + Result = !::CheckChildType( + Table, Index, N, SDISel.TLI, SDISel.CurDAG->getDataLayout(), + Table[Index - 1] - SelectionDAGISel::OPC_CheckChild0Type); + return Index; + case SelectionDAGISel::OPC_CheckCondCode: + Result = !::CheckCondCode(Table, Index, N); + return Index; + case SelectionDAGISel::OPC_CheckChild2CondCode: + Result = !::CheckChild2CondCode(Table, Index, N); + return Index; + case SelectionDAGISel::OPC_CheckValueType: + Result = !::CheckValueType(Table, Index, N, SDISel.TLI, + SDISel.CurDAG->getDataLayout()); + return Index; + case SelectionDAGISel::OPC_CheckInteger: + Result = !::CheckInteger(Table, Index, N); + return Index; + case SelectionDAGISel::OPC_CheckChild0Integer: + case SelectionDAGISel::OPC_CheckChild1Integer: + case SelectionDAGISel::OPC_CheckChild2Integer: + case SelectionDAGISel::OPC_CheckChild3Integer: + case SelectionDAGISel::OPC_CheckChild4Integer: + Result = !::CheckChildInteger(Table, Index, N, + Table[Index-1] - SelectionDAGISel::OPC_CheckChild0Integer); + return Index; + case SelectionDAGISel::OPC_CheckAndImm: + Result = !::CheckAndImm(Table, Index, N, SDISel); + return Index; + case SelectionDAGISel::OPC_CheckOrImm: + Result = !::CheckOrImm(Table, Index, N, SDISel); + return Index; + } +} + +namespace { + +struct MatchScope { + /// FailIndex - If this match fails, this is the index to continue with. + unsigned FailIndex; + + /// NodeStack - The node stack when the scope was formed. + SmallVector NodeStack; + + /// NumRecordedNodes - The number of recorded nodes when the scope was formed. + unsigned NumRecordedNodes; + + /// NumMatchedMemRefs - The number of matched memref entries. + unsigned NumMatchedMemRefs; + + /// InputChain/InputGlue - The current chain/glue + SDValue InputChain, InputGlue; + + /// HasChainNodesMatched - True if the ChainNodesMatched list is non-empty. + bool HasChainNodesMatched; +}; + +/// \A DAG update listener to keep the matching state +/// (i.e. RecordedNodes and MatchScope) uptodate if the target is allowed to +/// change the DAG while matching. X86 addressing mode matcher is an example +/// for this. +class MatchStateUpdater : public SelectionDAG::DAGUpdateListener +{ + SDNode **NodeToMatch; + SmallVectorImpl> &RecordedNodes; + SmallVectorImpl &MatchScopes; + +public: + MatchStateUpdater(SelectionDAG &DAG, SDNode **NodeToMatch, + SmallVectorImpl> &RN, + SmallVectorImpl &MS) + : SelectionDAG::DAGUpdateListener(DAG), NodeToMatch(NodeToMatch), + RecordedNodes(RN), MatchScopes(MS) {} + + void NodeDeleted(SDNode *N, SDNode *E) override { + // Some early-returns here to avoid the search if we deleted the node or + // if the update comes from MorphNodeTo (MorphNodeTo is the last thing we + // do, so it's unnecessary to update matching state at that point). + // Neither of these can occur currently because we only install this + // update listener during matching a complex patterns. + if (!E || E->isMachineOpcode()) + return; + // Check if NodeToMatch was updated. + if (N == *NodeToMatch) + *NodeToMatch = E; + // Performing linear search here does not matter because we almost never + // run this code. You'd have to have a CSE during complex pattern + // matching. + for (auto &I : RecordedNodes) + if (I.first.getNode() == N) + I.first.setNode(E); + + for (auto &I : MatchScopes) + for (auto &J : I.NodeStack) + if (J.getNode() == N) + J.setNode(E); + } +}; + +} // end anonymous namespace + +void SelectionDAGISel::SelectCodeCommon(SDNode *NodeToMatch, + const unsigned char *MatcherTable, + unsigned TableSize) { + // FIXME: Should these even be selected? Handle these cases in the caller? + switch (NodeToMatch->getOpcode()) { + default: + break; + case ISD::EntryToken: // These nodes remain the same. + case ISD::BasicBlock: + case ISD::Register: + case ISD::RegisterMask: + case ISD::HANDLENODE: + case ISD::MDNODE_SDNODE: + case ISD::TargetConstant: + case ISD::TargetConstantFP: + case ISD::TargetConstantPool: + case ISD::TargetFrameIndex: + case ISD::TargetExternalSymbol: + case ISD::MCSymbol: + case ISD::TargetBlockAddress: + case ISD::TargetJumpTable: + case ISD::TargetGlobalTLSAddress: + case ISD::TargetGlobalAddress: + case ISD::TokenFactor: + case ISD::CopyFromReg: + case ISD::CopyToReg: + case ISD::EH_LABEL: + case ISD::ANNOTATION_LABEL: + case ISD::LIFETIME_START: + case ISD::LIFETIME_END: + NodeToMatch->setNodeId(-1); // Mark selected. + return; + case ISD::AssertSext: + case ISD::AssertZext: + ReplaceUses(SDValue(NodeToMatch, 0), NodeToMatch->getOperand(0)); + CurDAG->RemoveDeadNode(NodeToMatch); + return; + case ISD::INLINEASM: + case ISD::INLINEASM_BR: + Select_INLINEASM(NodeToMatch, + NodeToMatch->getOpcode() == ISD::INLINEASM_BR); + return; + case ISD::READ_REGISTER: + Select_READ_REGISTER(NodeToMatch); + return; + case ISD::WRITE_REGISTER: + Select_WRITE_REGISTER(NodeToMatch); + return; + case ISD::UNDEF: + Select_UNDEF(NodeToMatch); + return; + } + + assert(!NodeToMatch->isMachineOpcode() && "Node already selected!"); + + // Set up the node stack with NodeToMatch as the only node on the stack. + SmallVector NodeStack; + SDValue N = SDValue(NodeToMatch, 0); + NodeStack.push_back(N); + + // MatchScopes - Scopes used when matching, if a match failure happens, this + // indicates where to continue checking. + SmallVector MatchScopes; + + // RecordedNodes - This is the set of nodes that have been recorded by the + // state machine. The second value is the parent of the node, or null if the + // root is recorded. + SmallVector, 8> RecordedNodes; + + // MatchedMemRefs - This is the set of MemRef's we've seen in the input + // pattern. + SmallVector MatchedMemRefs; + + // These are the current input chain and glue for use when generating nodes. + // Various Emit operations change these. For example, emitting a copytoreg + // uses and updates these. + SDValue InputChain, InputGlue; + + // ChainNodesMatched - If a pattern matches nodes that have input/output + // chains, the OPC_EmitMergeInputChains operation is emitted which indicates + // which ones they are. The result is captured into this list so that we can + // update the chain results when the pattern is complete. + SmallVector ChainNodesMatched; + + LLVM_DEBUG(dbgs() << "ISEL: Starting pattern match\n"); + + // Determine where to start the interpreter. Normally we start at opcode #0, + // but if the state machine starts with an OPC_SwitchOpcode, then we + // accelerate the first lookup (which is guaranteed to be hot) with the + // OpcodeOffset table. + unsigned MatcherIndex = 0; + + if (!OpcodeOffset.empty()) { + // Already computed the OpcodeOffset table, just index into it. + if (N.getOpcode() < OpcodeOffset.size()) + MatcherIndex = OpcodeOffset[N.getOpcode()]; + LLVM_DEBUG(dbgs() << " Initial Opcode index to " << MatcherIndex << "\n"); + + } else if (MatcherTable[0] == OPC_SwitchOpcode) { + // Otherwise, the table isn't computed, but the state machine does start + // with an OPC_SwitchOpcode instruction. Populate the table now, since this + // is the first time we're selecting an instruction. + unsigned Idx = 1; + while (true) { + // Get the size of this case. + unsigned CaseSize = MatcherTable[Idx++]; + if (CaseSize & 128) + CaseSize = GetVBR(CaseSize, MatcherTable, Idx); + if (CaseSize == 0) break; + + // Get the opcode, add the index to the table. + uint16_t Opc = MatcherTable[Idx++]; + Opc |= (unsigned short)MatcherTable[Idx++] << 8; + if (Opc >= OpcodeOffset.size()) + OpcodeOffset.resize((Opc+1)*2); + OpcodeOffset[Opc] = Idx; + Idx += CaseSize; + } + + // Okay, do the lookup for the first opcode. + if (N.getOpcode() < OpcodeOffset.size()) + MatcherIndex = OpcodeOffset[N.getOpcode()]; + } + + while (true) { + assert(MatcherIndex < TableSize && "Invalid index"); +#ifndef NDEBUG + unsigned CurrentOpcodeIndex = MatcherIndex; +#endif + BuiltinOpcodes Opcode = (BuiltinOpcodes)MatcherTable[MatcherIndex++]; + switch (Opcode) { + case OPC_Scope: { + // Okay, the semantics of this operation are that we should push a scope + // then evaluate the first child. However, pushing a scope only to have + // the first check fail (which then pops it) is inefficient. If we can + // determine immediately that the first check (or first several) will + // immediately fail, don't even bother pushing a scope for them. + unsigned FailIndex; + + while (true) { + unsigned NumToSkip = MatcherTable[MatcherIndex++]; + if (NumToSkip & 128) + NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex); + // Found the end of the scope with no match. + if (NumToSkip == 0) { + FailIndex = 0; + break; + } + + FailIndex = MatcherIndex+NumToSkip; + + unsigned MatcherIndexOfPredicate = MatcherIndex; + (void)MatcherIndexOfPredicate; // silence warning. + + // If we can't evaluate this predicate without pushing a scope (e.g. if + // it is a 'MoveParent') or if the predicate succeeds on this node, we + // push the scope and evaluate the full predicate chain. + bool Result; + MatcherIndex = IsPredicateKnownToFail(MatcherTable, MatcherIndex, N, + Result, *this, RecordedNodes); + if (!Result) + break; + + LLVM_DEBUG( + dbgs() << " Skipped scope entry (due to false predicate) at " + << "index " << MatcherIndexOfPredicate << ", continuing at " + << FailIndex << "\n"); + ++NumDAGIselRetries; + + // Otherwise, we know that this case of the Scope is guaranteed to fail, + // move to the next case. + MatcherIndex = FailIndex; + } + + // If the whole scope failed to match, bail. + if (FailIndex == 0) break; + + // Push a MatchScope which indicates where to go if the first child fails + // to match. + MatchScope NewEntry; + NewEntry.FailIndex = FailIndex; + NewEntry.NodeStack.append(NodeStack.begin(), NodeStack.end()); + NewEntry.NumRecordedNodes = RecordedNodes.size(); + NewEntry.NumMatchedMemRefs = MatchedMemRefs.size(); + NewEntry.InputChain = InputChain; + NewEntry.InputGlue = InputGlue; + NewEntry.HasChainNodesMatched = !ChainNodesMatched.empty(); + MatchScopes.push_back(NewEntry); + continue; + } + case OPC_RecordNode: { + // Remember this node, it may end up being an operand in the pattern. + SDNode *Parent = nullptr; + if (NodeStack.size() > 1) + Parent = NodeStack[NodeStack.size()-2].getNode(); + RecordedNodes.push_back(std::make_pair(N, Parent)); + continue; + } + + case OPC_RecordChild0: case OPC_RecordChild1: + case OPC_RecordChild2: case OPC_RecordChild3: + case OPC_RecordChild4: case OPC_RecordChild5: + case OPC_RecordChild6: case OPC_RecordChild7: { + unsigned ChildNo = Opcode-OPC_RecordChild0; + if (ChildNo >= N.getNumOperands()) + break; // Match fails if out of range child #. + + RecordedNodes.push_back(std::make_pair(N->getOperand(ChildNo), + N.getNode())); + continue; + } + case OPC_RecordMemRef: + if (auto *MN = dyn_cast(N)) + MatchedMemRefs.push_back(MN->getMemOperand()); + else { + LLVM_DEBUG(dbgs() << "Expected MemSDNode "; N->dump(CurDAG); + dbgs() << '\n'); + } + + continue; + + case OPC_CaptureGlueInput: + // If the current node has an input glue, capture it in InputGlue. + if (N->getNumOperands() != 0 && + N->getOperand(N->getNumOperands()-1).getValueType() == MVT::Glue) + InputGlue = N->getOperand(N->getNumOperands()-1); + continue; + + case OPC_MoveChild: { + unsigned ChildNo = MatcherTable[MatcherIndex++]; + if (ChildNo >= N.getNumOperands()) + break; // Match fails if out of range child #. + N = N.getOperand(ChildNo); + NodeStack.push_back(N); + continue; + } + + case OPC_MoveChild0: case OPC_MoveChild1: + case OPC_MoveChild2: case OPC_MoveChild3: + case OPC_MoveChild4: case OPC_MoveChild5: + case OPC_MoveChild6: case OPC_MoveChild7: { + unsigned ChildNo = Opcode-OPC_MoveChild0; + if (ChildNo >= N.getNumOperands()) + break; // Match fails if out of range child #. + N = N.getOperand(ChildNo); + NodeStack.push_back(N); + continue; + } + + case OPC_MoveParent: + // Pop the current node off the NodeStack. + NodeStack.pop_back(); + assert(!NodeStack.empty() && "Node stack imbalance!"); + N = NodeStack.back(); + continue; + + case OPC_CheckSame: + if (!::CheckSame(MatcherTable, MatcherIndex, N, RecordedNodes)) break; + continue; + + case OPC_CheckChild0Same: case OPC_CheckChild1Same: + case OPC_CheckChild2Same: case OPC_CheckChild3Same: + if (!::CheckChildSame(MatcherTable, MatcherIndex, N, RecordedNodes, + Opcode-OPC_CheckChild0Same)) + break; + continue; + + case OPC_CheckPatternPredicate: + if (!::CheckPatternPredicate(MatcherTable, MatcherIndex, *this)) break; + continue; + case OPC_CheckPredicate: + if (!::CheckNodePredicate(MatcherTable, MatcherIndex, *this, + N.getNode())) + break; + continue; + case OPC_CheckPredicateWithOperands: { + unsigned OpNum = MatcherTable[MatcherIndex++]; + SmallVector Operands; + + for (unsigned i = 0; i < OpNum; ++i) + Operands.push_back(RecordedNodes[MatcherTable[MatcherIndex++]].first); + + unsigned PredNo = MatcherTable[MatcherIndex++]; + if (!CheckNodePredicateWithOperands(N.getNode(), PredNo, Operands)) + break; + continue; + } + case OPC_CheckComplexPat: { + unsigned CPNum = MatcherTable[MatcherIndex++]; + unsigned RecNo = MatcherTable[MatcherIndex++]; + assert(RecNo < RecordedNodes.size() && "Invalid CheckComplexPat"); + + // If target can modify DAG during matching, keep the matching state + // consistent. + std::unique_ptr MSU; + if (ComplexPatternFuncMutatesDAG()) + MSU.reset(new MatchStateUpdater(*CurDAG, &NodeToMatch, RecordedNodes, + MatchScopes)); + + if (!CheckComplexPattern(NodeToMatch, RecordedNodes[RecNo].second, + RecordedNodes[RecNo].first, CPNum, + RecordedNodes)) + break; + continue; + } + case OPC_CheckOpcode: + if (!::CheckOpcode(MatcherTable, MatcherIndex, N.getNode())) break; + continue; + + case OPC_CheckType: + if (!::CheckType(MatcherTable, MatcherIndex, N, TLI, + CurDAG->getDataLayout())) + break; + continue; + + case OPC_CheckTypeRes: { + unsigned Res = MatcherTable[MatcherIndex++]; + if (!::CheckType(MatcherTable, MatcherIndex, N.getValue(Res), TLI, + CurDAG->getDataLayout())) + break; + continue; + } + + case OPC_SwitchOpcode: { + unsigned CurNodeOpcode = N.getOpcode(); + unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart; + unsigned CaseSize; + while (true) { + // Get the size of this case. + CaseSize = MatcherTable[MatcherIndex++]; + if (CaseSize & 128) + CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex); + if (CaseSize == 0) break; + + uint16_t Opc = MatcherTable[MatcherIndex++]; + Opc |= (unsigned short)MatcherTable[MatcherIndex++] << 8; + + // If the opcode matches, then we will execute this case. + if (CurNodeOpcode == Opc) + break; + + // Otherwise, skip over this case. + MatcherIndex += CaseSize; + } + + // If no cases matched, bail out. + if (CaseSize == 0) break; + + // Otherwise, execute the case we found. + LLVM_DEBUG(dbgs() << " OpcodeSwitch from " << SwitchStart << " to " + << MatcherIndex << "\n"); + continue; + } + + case OPC_SwitchType: { + MVT CurNodeVT = N.getSimpleValueType(); + unsigned SwitchStart = MatcherIndex-1; (void)SwitchStart; + unsigned CaseSize; + while (true) { + // Get the size of this case. + CaseSize = MatcherTable[MatcherIndex++]; + if (CaseSize & 128) + CaseSize = GetVBR(CaseSize, MatcherTable, MatcherIndex); + if (CaseSize == 0) break; + + MVT CaseVT = (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + if (CaseVT == MVT::iPTR) + CaseVT = TLI->getPointerTy(CurDAG->getDataLayout()); + + // If the VT matches, then we will execute this case. + if (CurNodeVT == CaseVT) + break; + + // Otherwise, skip over this case. + MatcherIndex += CaseSize; + } + + // If no cases matched, bail out. + if (CaseSize == 0) break; + + // Otherwise, execute the case we found. + LLVM_DEBUG(dbgs() << " TypeSwitch[" << EVT(CurNodeVT).getEVTString() + << "] from " << SwitchStart << " to " << MatcherIndex + << '\n'); + continue; + } + case OPC_CheckChild0Type: case OPC_CheckChild1Type: + case OPC_CheckChild2Type: case OPC_CheckChild3Type: + case OPC_CheckChild4Type: case OPC_CheckChild5Type: + case OPC_CheckChild6Type: case OPC_CheckChild7Type: + if (!::CheckChildType(MatcherTable, MatcherIndex, N, TLI, + CurDAG->getDataLayout(), + Opcode - OPC_CheckChild0Type)) + break; + continue; + case OPC_CheckCondCode: + if (!::CheckCondCode(MatcherTable, MatcherIndex, N)) break; + continue; + case OPC_CheckChild2CondCode: + if (!::CheckChild2CondCode(MatcherTable, MatcherIndex, N)) break; + continue; + case OPC_CheckValueType: + if (!::CheckValueType(MatcherTable, MatcherIndex, N, TLI, + CurDAG->getDataLayout())) + break; + continue; + case OPC_CheckInteger: + if (!::CheckInteger(MatcherTable, MatcherIndex, N)) break; + continue; + case OPC_CheckChild0Integer: case OPC_CheckChild1Integer: + case OPC_CheckChild2Integer: case OPC_CheckChild3Integer: + case OPC_CheckChild4Integer: + if (!::CheckChildInteger(MatcherTable, MatcherIndex, N, + Opcode-OPC_CheckChild0Integer)) break; + continue; + case OPC_CheckAndImm: + if (!::CheckAndImm(MatcherTable, MatcherIndex, N, *this)) break; + continue; + case OPC_CheckOrImm: + if (!::CheckOrImm(MatcherTable, MatcherIndex, N, *this)) break; + continue; + case OPC_CheckImmAllOnesV: + if (!ISD::isBuildVectorAllOnes(N.getNode())) break; + continue; + case OPC_CheckImmAllZerosV: + if (!ISD::isBuildVectorAllZeros(N.getNode())) break; + continue; + + case OPC_CheckFoldableChainNode: { + assert(NodeStack.size() != 1 && "No parent node"); + // Verify that all intermediate nodes between the root and this one have + // a single use. + bool HasMultipleUses = false; + for (unsigned i = 1, e = NodeStack.size()-1; i != e; ++i) + if (!NodeStack[i].getNode()->hasOneUse()) { + HasMultipleUses = true; + break; + } + if (HasMultipleUses) break; + + // Check to see that the target thinks this is profitable to fold and that + // we can fold it without inducing cycles in the graph. + if (!IsProfitableToFold(N, NodeStack[NodeStack.size()-2].getNode(), + NodeToMatch) || + !IsLegalToFold(N, NodeStack[NodeStack.size()-2].getNode(), + NodeToMatch, OptLevel, + true/*We validate our own chains*/)) + break; + + continue; + } + case OPC_EmitInteger: { + MVT::SimpleValueType VT = + (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + int64_t Val = MatcherTable[MatcherIndex++]; + if (Val & 128) + Val = GetVBR(Val, MatcherTable, MatcherIndex); + RecordedNodes.push_back(std::pair( + CurDAG->getTargetConstant(Val, SDLoc(NodeToMatch), + VT), nullptr)); + continue; + } + case OPC_EmitRegister: { + MVT::SimpleValueType VT = + (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + unsigned RegNo = MatcherTable[MatcherIndex++]; + RecordedNodes.push_back(std::pair( + CurDAG->getRegister(RegNo, VT), nullptr)); + continue; + } + case OPC_EmitRegister2: { + // For targets w/ more than 256 register names, the register enum + // values are stored in two bytes in the matcher table (just like + // opcodes). + MVT::SimpleValueType VT = + (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + unsigned RegNo = MatcherTable[MatcherIndex++]; + RegNo |= MatcherTable[MatcherIndex++] << 8; + RecordedNodes.push_back(std::pair( + CurDAG->getRegister(RegNo, VT), nullptr)); + continue; + } + + case OPC_EmitConvertToTarget: { + // Convert from IMM/FPIMM to target version. + unsigned RecNo = MatcherTable[MatcherIndex++]; + assert(RecNo < RecordedNodes.size() && "Invalid EmitConvertToTarget"); + SDValue Imm = RecordedNodes[RecNo].first; + + if (Imm->getOpcode() == ISD::Constant) { + const ConstantInt *Val=cast(Imm)->getConstantIntValue(); + Imm = CurDAG->getTargetConstant(*Val, SDLoc(NodeToMatch), + Imm.getValueType()); + } else if (Imm->getOpcode() == ISD::ConstantFP) { + const ConstantFP *Val=cast(Imm)->getConstantFPValue(); + Imm = CurDAG->getTargetConstantFP(*Val, SDLoc(NodeToMatch), + Imm.getValueType()); + } + + RecordedNodes.push_back(std::make_pair(Imm, RecordedNodes[RecNo].second)); + continue; + } + + case OPC_EmitMergeInputChains1_0: // OPC_EmitMergeInputChains, 1, 0 + case OPC_EmitMergeInputChains1_1: // OPC_EmitMergeInputChains, 1, 1 + case OPC_EmitMergeInputChains1_2: { // OPC_EmitMergeInputChains, 1, 2 + // These are space-optimized forms of OPC_EmitMergeInputChains. + assert(!InputChain.getNode() && + "EmitMergeInputChains should be the first chain producing node"); + assert(ChainNodesMatched.empty() && + "Should only have one EmitMergeInputChains per match"); + + // Read all of the chained nodes. + unsigned RecNo = Opcode - OPC_EmitMergeInputChains1_0; + assert(RecNo < RecordedNodes.size() && "Invalid EmitMergeInputChains"); + ChainNodesMatched.push_back(RecordedNodes[RecNo].first.getNode()); + + // FIXME: What if other value results of the node have uses not matched + // by this pattern? + if (ChainNodesMatched.back() != NodeToMatch && + !RecordedNodes[RecNo].first.hasOneUse()) { + ChainNodesMatched.clear(); + break; + } + + // Merge the input chains if they are not intra-pattern references. + InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG); + + if (!InputChain.getNode()) + break; // Failed to merge. + continue; + } + + case OPC_EmitMergeInputChains: { + assert(!InputChain.getNode() && + "EmitMergeInputChains should be the first chain producing node"); + // This node gets a list of nodes we matched in the input that have + // chains. We want to token factor all of the input chains to these nodes + // together. However, if any of the input chains is actually one of the + // nodes matched in this pattern, then we have an intra-match reference. + // Ignore these because the newly token factored chain should not refer to + // the old nodes. + unsigned NumChains = MatcherTable[MatcherIndex++]; + assert(NumChains != 0 && "Can't TF zero chains"); + + assert(ChainNodesMatched.empty() && + "Should only have one EmitMergeInputChains per match"); + + // Read all of the chained nodes. + for (unsigned i = 0; i != NumChains; ++i) { + unsigned RecNo = MatcherTable[MatcherIndex++]; + assert(RecNo < RecordedNodes.size() && "Invalid EmitMergeInputChains"); + ChainNodesMatched.push_back(RecordedNodes[RecNo].first.getNode()); + + // FIXME: What if other value results of the node have uses not matched + // by this pattern? + if (ChainNodesMatched.back() != NodeToMatch && + !RecordedNodes[RecNo].first.hasOneUse()) { + ChainNodesMatched.clear(); + break; + } + } + + // If the inner loop broke out, the match fails. + if (ChainNodesMatched.empty()) + break; + + // Merge the input chains if they are not intra-pattern references. + InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG); + + if (!InputChain.getNode()) + break; // Failed to merge. + + continue; + } + + case OPC_EmitCopyToReg: + case OPC_EmitCopyToReg2: { + unsigned RecNo = MatcherTable[MatcherIndex++]; + assert(RecNo < RecordedNodes.size() && "Invalid EmitCopyToReg"); + unsigned DestPhysReg = MatcherTable[MatcherIndex++]; + if (Opcode == OPC_EmitCopyToReg2) + DestPhysReg |= MatcherTable[MatcherIndex++] << 8; + + if (!InputChain.getNode()) + InputChain = CurDAG->getEntryNode(); + + InputChain = CurDAG->getCopyToReg(InputChain, SDLoc(NodeToMatch), + DestPhysReg, RecordedNodes[RecNo].first, + InputGlue); + + InputGlue = InputChain.getValue(1); + continue; + } + + case OPC_EmitNodeXForm: { + unsigned XFormNo = MatcherTable[MatcherIndex++]; + unsigned RecNo = MatcherTable[MatcherIndex++]; + assert(RecNo < RecordedNodes.size() && "Invalid EmitNodeXForm"); + SDValue Res = RunSDNodeXForm(RecordedNodes[RecNo].first, XFormNo); + RecordedNodes.push_back(std::pair(Res, nullptr)); + continue; + } + case OPC_Coverage: { + // This is emitted right before MorphNode/EmitNode. + // So it should be safe to assume that this node has been selected + unsigned index = MatcherTable[MatcherIndex++]; + index |= (MatcherTable[MatcherIndex++] << 8); + dbgs() << "COVERED: " << getPatternForIndex(index) << "\n"; + dbgs() << "INCLUDED: " << getIncludePathForIndex(index) << "\n"; + continue; + } + + case OPC_EmitNode: case OPC_MorphNodeTo: + case OPC_EmitNode0: case OPC_EmitNode1: case OPC_EmitNode2: + case OPC_MorphNodeTo0: case OPC_MorphNodeTo1: case OPC_MorphNodeTo2: { + uint16_t TargetOpc = MatcherTable[MatcherIndex++]; + TargetOpc |= (unsigned short)MatcherTable[MatcherIndex++] << 8; + unsigned EmitNodeInfo = MatcherTable[MatcherIndex++]; + // Get the result VT list. + unsigned NumVTs; + // If this is one of the compressed forms, get the number of VTs based + // on the Opcode. Otherwise read the next byte from the table. + if (Opcode >= OPC_MorphNodeTo0 && Opcode <= OPC_MorphNodeTo2) + NumVTs = Opcode - OPC_MorphNodeTo0; + else if (Opcode >= OPC_EmitNode0 && Opcode <= OPC_EmitNode2) + NumVTs = Opcode - OPC_EmitNode0; + else + NumVTs = MatcherTable[MatcherIndex++]; + SmallVector VTs; + for (unsigned i = 0; i != NumVTs; ++i) { + MVT::SimpleValueType VT = + (MVT::SimpleValueType)MatcherTable[MatcherIndex++]; + if (VT == MVT::iPTR) + VT = TLI->getPointerTy(CurDAG->getDataLayout()).SimpleTy; + VTs.push_back(VT); + } + + if (EmitNodeInfo & OPFL_Chain) + VTs.push_back(MVT::Other); + if (EmitNodeInfo & OPFL_GlueOutput) + VTs.push_back(MVT::Glue); + + // This is hot code, so optimize the two most common cases of 1 and 2 + // results. + SDVTList VTList; + if (VTs.size() == 1) + VTList = CurDAG->getVTList(VTs[0]); + else if (VTs.size() == 2) + VTList = CurDAG->getVTList(VTs[0], VTs[1]); + else + VTList = CurDAG->getVTList(VTs); + + // Get the operand list. + unsigned NumOps = MatcherTable[MatcherIndex++]; + SmallVector Ops; + for (unsigned i = 0; i != NumOps; ++i) { + unsigned RecNo = MatcherTable[MatcherIndex++]; + if (RecNo & 128) + RecNo = GetVBR(RecNo, MatcherTable, MatcherIndex); + + assert(RecNo < RecordedNodes.size() && "Invalid EmitNode"); + Ops.push_back(RecordedNodes[RecNo].first); + } + + // If there are variadic operands to add, handle them now. + if (EmitNodeInfo & OPFL_VariadicInfo) { + // Determine the start index to copy from. + unsigned FirstOpToCopy = getNumFixedFromVariadicInfo(EmitNodeInfo); + FirstOpToCopy += (EmitNodeInfo & OPFL_Chain) ? 1 : 0; + assert(NodeToMatch->getNumOperands() >= FirstOpToCopy && + "Invalid variadic node"); + // Copy all of the variadic operands, not including a potential glue + // input. + for (unsigned i = FirstOpToCopy, e = NodeToMatch->getNumOperands(); + i != e; ++i) { + SDValue V = NodeToMatch->getOperand(i); + if (V.getValueType() == MVT::Glue) break; + Ops.push_back(V); + } + } + + // If this has chain/glue inputs, add them. + if (EmitNodeInfo & OPFL_Chain) + Ops.push_back(InputChain); + if ((EmitNodeInfo & OPFL_GlueInput) && InputGlue.getNode() != nullptr) + Ops.push_back(InputGlue); + + // Create the node. + MachineSDNode *Res = nullptr; + bool IsMorphNodeTo = Opcode == OPC_MorphNodeTo || + (Opcode >= OPC_MorphNodeTo0 && Opcode <= OPC_MorphNodeTo2); + if (!IsMorphNodeTo) { + // If this is a normal EmitNode command, just create the new node and + // add the results to the RecordedNodes list. + Res = CurDAG->getMachineNode(TargetOpc, SDLoc(NodeToMatch), + VTList, Ops); + + // Add all the non-glue/non-chain results to the RecordedNodes list. + for (unsigned i = 0, e = VTs.size(); i != e; ++i) { + if (VTs[i] == MVT::Other || VTs[i] == MVT::Glue) break; + RecordedNodes.push_back(std::pair(SDValue(Res, i), + nullptr)); + } + } else { + assert(NodeToMatch->getOpcode() != ISD::DELETED_NODE && + "NodeToMatch was removed partway through selection"); + SelectionDAG::DAGNodeDeletedListener NDL(*CurDAG, [&](SDNode *N, + SDNode *E) { + CurDAG->salvageDebugInfo(*N); + auto &Chain = ChainNodesMatched; + assert((!E || !is_contained(Chain, N)) && + "Chain node replaced during MorphNode"); + Chain.erase(std::remove(Chain.begin(), Chain.end(), N), Chain.end()); + }); + Res = cast(MorphNode(NodeToMatch, TargetOpc, VTList, + Ops, EmitNodeInfo)); + } + + // If the node had chain/glue results, update our notion of the current + // chain and glue. + if (EmitNodeInfo & OPFL_GlueOutput) { + InputGlue = SDValue(Res, VTs.size()-1); + if (EmitNodeInfo & OPFL_Chain) + InputChain = SDValue(Res, VTs.size()-2); + } else if (EmitNodeInfo & OPFL_Chain) + InputChain = SDValue(Res, VTs.size()-1); + + // If the OPFL_MemRefs glue is set on this node, slap all of the + // accumulated memrefs onto it. + // + // FIXME: This is vastly incorrect for patterns with multiple outputs + // instructions that access memory and for ComplexPatterns that match + // loads. + if (EmitNodeInfo & OPFL_MemRefs) { + // Only attach load or store memory operands if the generated + // instruction may load or store. + const MCInstrDesc &MCID = TII->get(TargetOpc); + bool mayLoad = MCID.mayLoad(); + bool mayStore = MCID.mayStore(); + + // We expect to have relatively few of these so just filter them into a + // temporary buffer so that we can easily add them to the instruction. + SmallVector FilteredMemRefs; + for (MachineMemOperand *MMO : MatchedMemRefs) { + if (MMO->isLoad()) { + if (mayLoad) + FilteredMemRefs.push_back(MMO); + } else if (MMO->isStore()) { + if (mayStore) + FilteredMemRefs.push_back(MMO); + } else { + FilteredMemRefs.push_back(MMO); + } + } + + CurDAG->setNodeMemRefs(Res, FilteredMemRefs); + } + + LLVM_DEBUG(if (!MatchedMemRefs.empty() && Res->memoperands_empty()) dbgs() + << " Dropping mem operands\n"; + dbgs() << " " << (IsMorphNodeTo ? "Morphed" : "Created") + << " node: "; + Res->dump(CurDAG);); + + // If this was a MorphNodeTo then we're completely done! + if (IsMorphNodeTo) { + // Update chain uses. + UpdateChains(Res, InputChain, ChainNodesMatched, true); + return; + } + continue; + } + + case OPC_CompleteMatch: { + // The match has been completed, and any new nodes (if any) have been + // created. Patch up references to the matched dag to use the newly + // created nodes. + unsigned NumResults = MatcherTable[MatcherIndex++]; + + for (unsigned i = 0; i != NumResults; ++i) { + unsigned ResSlot = MatcherTable[MatcherIndex++]; + if (ResSlot & 128) + ResSlot = GetVBR(ResSlot, MatcherTable, MatcherIndex); + + assert(ResSlot < RecordedNodes.size() && "Invalid CompleteMatch"); + SDValue Res = RecordedNodes[ResSlot].first; + + assert(i < NodeToMatch->getNumValues() && + NodeToMatch->getValueType(i) != MVT::Other && + NodeToMatch->getValueType(i) != MVT::Glue && + "Invalid number of results to complete!"); + assert((NodeToMatch->getValueType(i) == Res.getValueType() || + NodeToMatch->getValueType(i) == MVT::iPTR || + Res.getValueType() == MVT::iPTR || + NodeToMatch->getValueType(i).getSizeInBits() == + Res.getValueSizeInBits()) && + "invalid replacement"); + ReplaceUses(SDValue(NodeToMatch, i), Res); + } + + // Update chain uses. + UpdateChains(NodeToMatch, InputChain, ChainNodesMatched, false); + + // If the root node defines glue, we need to update it to the glue result. + // TODO: This never happens in our tests and I think it can be removed / + // replaced with an assert, but if we do it this the way the change is + // NFC. + if (NodeToMatch->getValueType(NodeToMatch->getNumValues() - 1) == + MVT::Glue && + InputGlue.getNode()) + ReplaceUses(SDValue(NodeToMatch, NodeToMatch->getNumValues() - 1), + InputGlue); + + assert(NodeToMatch->use_empty() && + "Didn't replace all uses of the node?"); + CurDAG->RemoveDeadNode(NodeToMatch); + + return; + } + } + + // If the code reached this point, then the match failed. See if there is + // another child to try in the current 'Scope', otherwise pop it until we + // find a case to check. + LLVM_DEBUG(dbgs() << " Match failed at index " << CurrentOpcodeIndex + << "\n"); + ++NumDAGIselRetries; + while (true) { + if (MatchScopes.empty()) { + CannotYetSelect(NodeToMatch); + return; + } + + // Restore the interpreter state back to the point where the scope was + // formed. + MatchScope &LastScope = MatchScopes.back(); + RecordedNodes.resize(LastScope.NumRecordedNodes); + NodeStack.clear(); + NodeStack.append(LastScope.NodeStack.begin(), LastScope.NodeStack.end()); + N = NodeStack.back(); + + if (LastScope.NumMatchedMemRefs != MatchedMemRefs.size()) + MatchedMemRefs.resize(LastScope.NumMatchedMemRefs); + MatcherIndex = LastScope.FailIndex; + + LLVM_DEBUG(dbgs() << " Continuing at " << MatcherIndex << "\n"); + + InputChain = LastScope.InputChain; + InputGlue = LastScope.InputGlue; + if (!LastScope.HasChainNodesMatched) + ChainNodesMatched.clear(); + + // Check to see what the offset is at the new MatcherIndex. If it is zero + // we have reached the end of this scope, otherwise we have another child + // in the current scope to try. + unsigned NumToSkip = MatcherTable[MatcherIndex++]; + if (NumToSkip & 128) + NumToSkip = GetVBR(NumToSkip, MatcherTable, MatcherIndex); + + // If we have another child in this scope to match, update FailIndex and + // try it. + if (NumToSkip != 0) { + LastScope.FailIndex = MatcherIndex+NumToSkip; + break; + } + + // End of this scope, pop it and try the next child in the containing + // scope. + MatchScopes.pop_back(); + } + } +} + +bool SelectionDAGISel::isOrEquivalentToAdd(const SDNode *N) const { + assert(N->getOpcode() == ISD::OR && "Unexpected opcode"); + auto *C = dyn_cast(N->getOperand(1)); + if (!C) + return false; + + // Detect when "or" is used to add an offset to a stack object. + if (auto *FN = dyn_cast(N->getOperand(0))) { + MachineFrameInfo &MFI = MF->getFrameInfo(); + unsigned A = MFI.getObjectAlignment(FN->getIndex()); + assert(isPowerOf2_32(A) && "Unexpected alignment"); + int32_t Off = C->getSExtValue(); + // If the alleged offset fits in the zero bits guaranteed by + // the alignment, then this or is really an add. + return (Off >= 0) && (((A - 1) & Off) == unsigned(Off)); + } + return false; +} + +void SelectionDAGISel::CannotYetSelect(SDNode *N) { + std::string msg; + raw_string_ostream Msg(msg); + Msg << "Cannot select: "; + + if (N->getOpcode() != ISD::INTRINSIC_W_CHAIN && + N->getOpcode() != ISD::INTRINSIC_WO_CHAIN && + N->getOpcode() != ISD::INTRINSIC_VOID) { + N->printrFull(Msg, CurDAG); + Msg << "\nIn function: " << MF->getName(); + } else { + bool HasInputChain = N->getOperand(0).getValueType() == MVT::Other; + unsigned iid = + cast(N->getOperand(HasInputChain))->getZExtValue(); + if (iid < Intrinsic::num_intrinsics) + Msg << "intrinsic %" << Intrinsic::getName((Intrinsic::ID)iid, None); + else if (const TargetIntrinsicInfo *TII = TM.getIntrinsicInfo()) + Msg << "target intrinsic %" << TII->getName(iid); + else + Msg << "unknown intrinsic #" << iid; + } + report_fatal_error(Msg.str()); +} + +char SelectionDAGISel::ID = 0; Index: llvm/test/CodeGen/X86/phi-node-elimination-dbg-invariant.mir =================================================================== --- /dev/null +++ llvm/test/CodeGen/X86/phi-node-elimination-dbg-invariant.mir @@ -0,0 +1,48 @@ +# RUN: llc -mtriple=x86_64-- -run-pass phi-node-elimination -o - %s | FileCheck %s +# Debug instruction should not impact PHI node lower when +# the PHI node is at the top of the specified block +# Fix issue: https://bugs.llvm.org/show_bug.cgi?id=43859 + +--- +name: test1 +tracksRegLiveness: true +registers: +body: | + ; Verify PHI lowering without Debug instruction exist + ; CHECK-LABEL: name: test1 + ; CHECK: bb.2: + ; CHECK: EH_LABEL 0 + ; CHECK: %1:gr32 = COPY %3 + bb.0: + %0:gr32 = IMPLICIT_DEF + JMP_1 %bb.2 + + bb.1: + + bb.2: + %1:gr32 = PHI %0:gr32, %bb.0, %2:gr32, %bb.1 + EH_LABEL 0 + %2:gr32 = ADD32ri8 killed %1:gr32, 1, implicit-def $eflags +... + +--- +name: test2 +tracksRegLiveness: true +body: | + ; Verify PHI lowering with Debug instruction exist + ; CHECK-LABEL: name: test2 + ; CHECK: bb.2: + ; CHECK: EH_LABEL 0 + ; CHECK: %1:gr32 = COPY %3 + bb.0: + %0:gr32 = IMPLICIT_DEF + JMP_1 %bb.2 + + bb.1: + + bb.2: + %1:gr32 = PHI %0:gr32, %bb.0, %2:gr32, %bb.1 + DBG_VALUE + EH_LABEL 0 + %2:gr32 = ADD32ri8 killed %1:gr32, 1, implicit-def $eflags +...