llvm/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

//===- SelectionDAGBuilder.cpp - Selection-DAG building -------------------===//
//
// 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 routines for translating from LLVM IR into SelectionDAG IR.
//
//===----------------------------------------------------------------------===//

#include "SelectionDAGBuilder.h"
#include "SDNodeDbgValue.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/AssignmentTrackingAnalysis.h"
#include "llvm/CodeGen/CodeGenCommonISel.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/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineInstrBundleIterator.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RuntimeLibcallUtil.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGTargetInfo.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/SwiftErrorValueTracking.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/EHPersonalities.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicsAArch64.h"
#include "llvm/IR/IntrinsicsAMDGPU.h"
#include "llvm/IR/IntrinsicsWebAssembly.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MemoryModelRelaxationAnnotations.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Statepoint.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/InstructionCost.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/Utils/Local.h"
#include <cstddef>
#include <deque>
#include <iterator>
#include <limits>
#include <optional>
#include <tuple>

usingnamespacellvm;
usingnamespacePatternMatch;
usingnamespaceSwitchCG;

#define DEBUG_TYPE

/// LimitFloatPrecision - Generate low-precision inline sequences for
/// some float libcalls (6, 8 or 12 bits).
static unsigned LimitFloatPrecision;

static cl::opt<bool>
    InsertAssertAlign("insert-assert-align", cl::init(true),
                      cl::desc("Insert the experimental `assertalign` node."),
                      cl::ReallyHidden);

static cl::opt<unsigned, true>
    LimitFPPrecision("limit-float-precision",
                     cl::desc("Generate low-precision inline sequences "
                              "for some float libcalls"),
                     cl::location(LimitFloatPrecision), cl::Hidden,
                     cl::init(0));

static cl::opt<unsigned> SwitchPeelThreshold(
    "switch-peel-threshold", cl::Hidden, cl::init(66),
    cl::desc("Set the case probability threshold for peeling the case from a "
             "switch statement. A value greater than 100 will void this "
             "optimization"));

// Limit the width of DAG chains. This is important in general to prevent
// DAG-based analysis from blowing up. For example, alias analysis and
// load clustering may not complete in reasonable time. It is difficult to
// recognize and avoid this situation within each individual analysis, and
// future analyses are likely to have the same behavior. Limiting DAG width is
// the safe approach and will be especially important with global DAGs.
//
// MaxParallelChains default is arbitrarily high to avoid affecting
// optimization, but could be lowered to improve compile time. Any ld-ld-st-st
// sequence over this should have been converted to llvm.memcpy by the
// frontend. It is easy to induce this behavior with .ll code such as:
// %buffer = alloca [4096 x i8]
// %data = load [4096 x i8]* %argPtr
// store [4096 x i8] %data, [4096 x i8]* %buffer
static const unsigned MaxParallelChains =;

static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL,
                                      const SDValue *Parts, unsigned NumParts,
                                      MVT PartVT, EVT ValueVT, const Value *V,
                                      SDValue InChain,
                                      std::optional<CallingConv::ID> CC);

/// getCopyFromParts - Create a value that contains the specified legal parts
/// combined into the value they represent.  If the parts combine to a type
/// larger than ValueVT then AssertOp can be used to specify whether the extra
/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT
/// (ISD::AssertSext).
static SDValue
getCopyFromParts(SelectionDAG &DAG, const SDLoc &DL, const SDValue *Parts,
                 unsigned NumParts, MVT PartVT, EVT ValueVT, const Value *V,
                 SDValue InChain,
                 std::optional<CallingConv::ID> CC = std::nullopt,
                 std::optional<ISD::NodeType> AssertOp = std::nullopt) {}

static void diagnosePossiblyInvalidConstraint(LLVMContext &Ctx, const Value *V,
                                              const Twine &ErrMsg) {}

/// getCopyFromPartsVector - Create a value that contains the specified legal
/// parts combined into the value they represent.  If the parts combine to a
/// type larger than ValueVT then AssertOp can be used to specify whether the
/// extra bits are known to be zero (ISD::AssertZext) or sign extended from
/// ValueVT (ISD::AssertSext).
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL,
                                      const SDValue *Parts, unsigned NumParts,
                                      MVT PartVT, EVT ValueVT, const Value *V,
                                      SDValue InChain,
                                      std::optional<CallingConv::ID> CallConv) {}

static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &dl,
                                 SDValue Val, SDValue *Parts, unsigned NumParts,
                                 MVT PartVT, const Value *V,
                                 std::optional<CallingConv::ID> CallConv);

/// getCopyToParts - Create a series of nodes that contain the specified value
/// split into legal parts.  If the parts contain more bits than Val, then, for
/// integers, ExtendKind can be used to specify how to generate the extra bits.
static void
getCopyToParts(SelectionDAG &DAG, const SDLoc &DL, SDValue Val, SDValue *Parts,
               unsigned NumParts, MVT PartVT, const Value *V,
               std::optional<CallingConv::ID> CallConv = std::nullopt,
               ISD::NodeType ExtendKind = ISD::ANY_EXTEND) {}

static SDValue widenVectorToPartType(SelectionDAG &DAG, SDValue Val,
                                     const SDLoc &DL, EVT PartVT) {}

/// getCopyToPartsVector - Create a series of nodes that contain the specified
/// value split into legal parts.
static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &DL,
                                 SDValue Val, SDValue *Parts, unsigned NumParts,
                                 MVT PartVT, const Value *V,
                                 std::optional<CallingConv::ID> CallConv) {}

RegsForValue::RegsForValue(const SmallVector<unsigned, 4> &regs, MVT regvt,
                           EVT valuevt, std::optional<CallingConv::ID> CC)
    :{}

RegsForValue::RegsForValue(LLVMContext &Context, const TargetLowering &TLI,
                           const DataLayout &DL, unsigned Reg, Type *Ty,
                           std::optional<CallingConv::ID> CC) {}

SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG,
                                      FunctionLoweringInfo &FuncInfo,
                                      const SDLoc &dl, SDValue &Chain,
                                      SDValue *Glue, const Value *V) const {}

void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG,
                                 const SDLoc &dl, SDValue &Chain, SDValue *Glue,
                                 const Value *V,
                                 ISD::NodeType PreferredExtendType) const {}

void RegsForValue::AddInlineAsmOperands(InlineAsm::Kind Code, bool HasMatching,
                                        unsigned MatchingIdx, const SDLoc &dl,
                                        SelectionDAG &DAG,
                                        std::vector<SDValue> &Ops) const {}

SmallVector<std::pair<unsigned, TypeSize>, 4>
RegsForValue::getRegsAndSizes() const {}

void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis *aa,
                               AssumptionCache *ac,
                               const TargetLibraryInfo *li) {}

void SelectionDAGBuilder::clear() {}

void SelectionDAGBuilder::clearDanglingDebugInfo() {}

// Update DAG root to include dependencies on Pending chains.
SDValue SelectionDAGBuilder::updateRoot(SmallVectorImpl<SDValue> &Pending) {}

SDValue SelectionDAGBuilder::getMemoryRoot() {}

SDValue SelectionDAGBuilder::getRoot() {}

SDValue SelectionDAGBuilder::getControlRoot() {}

void SelectionDAGBuilder::handleDebugDeclare(Value *Address,
                                             DILocalVariable *Variable,
                                             DIExpression *Expression,
                                             DebugLoc DL) {}

void SelectionDAGBuilder::visitDbgInfo(const Instruction &I) {}

void SelectionDAGBuilder::visit(const Instruction &I) {}

void SelectionDAGBuilder::visitPHI(const PHINode &) {}

void SelectionDAGBuilder::visit(unsigned Opcode, const User &I) {}

static bool handleDanglingVariadicDebugInfo(SelectionDAG &DAG,
                                            DILocalVariable *Variable,
                                            DebugLoc DL, unsigned Order,
                                            SmallVectorImpl<Value *> &Values,
                                            DIExpression *Expression) {}

void SelectionDAGBuilder::addDanglingDebugInfo(SmallVectorImpl<Value *> &Values,
                                               DILocalVariable *Var,
                                               DIExpression *Expr,
                                               bool IsVariadic, DebugLoc DL,
                                               unsigned Order) {}

void SelectionDAGBuilder::dropDanglingDebugInfo(const DILocalVariable *Variable,
                                                const DIExpression *Expr) {}

// resolveDanglingDebugInfo - if we saw an earlier dbg_value referring to V,
// generate the debug data structures now that we've seen its definition.
void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
                                                   SDValue Val) {}

void SelectionDAGBuilder::salvageUnresolvedDbgValue(const Value *V,
                                                    DanglingDebugInfo &DDI) {}

void SelectionDAGBuilder::handleKillDebugValue(DILocalVariable *Var,
                                               DIExpression *Expr,
                                               DebugLoc DbgLoc,
                                               unsigned Order) {}

bool SelectionDAGBuilder::handleDebugValue(ArrayRef<const Value *> Values,
                                           DILocalVariable *Var,
                                           DIExpression *Expr, DebugLoc DbgLoc,
                                           unsigned Order, bool IsVariadic) {}

void SelectionDAGBuilder::resolveOrClearDbgInfo() {}

/// getCopyFromRegs - If there was virtual register allocated for the value V
/// emit CopyFromReg of the specified type Ty. Return empty SDValue() otherwise.
SDValue SelectionDAGBuilder::getCopyFromRegs(const Value *V, Type *Ty) {}

/// getValue - Return an SDValue for the given Value.
SDValue SelectionDAGBuilder::getValue(const Value *V) {}

/// getNonRegisterValue - Return an SDValue for the given Value, but
/// don't look in FuncInfo.ValueMap for a virtual register.
SDValue SelectionDAGBuilder::getNonRegisterValue(const Value *V) {}

/// getValueImpl - Helper function for getValue and getNonRegisterValue.
/// Create an SDValue for the given value.
SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {}

void SelectionDAGBuilder::visitCatchPad(const CatchPadInst &I) {}

void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) {}

void SelectionDAGBuilder::visitCleanupPad(const CleanupPadInst &CPI) {}

// In wasm EH, even though a catchpad may not catch an exception if a tag does
// not match, it is OK to add only the first unwind destination catchpad to the
// successors, because there will be at least one invoke instruction within the
// catch scope that points to the next unwind destination, if one exists, so
// CFGSort cannot mess up with BB sorting order.
// (All catchpads with 'catch (type)' clauses have a 'llvm.rethrow' intrinsic
// call within them, and catchpads only consisting of 'catch (...)' have a
// '__cxa_end_catch' call within them, both of which generate invokes in case
// the next unwind destination exists, i.e., the next unwind destination is not
// the caller.)
//
// Having at most one EH pad successor is also simpler and helps later
// transformations.
//
// For example,
// current:
//   invoke void @foo to ... unwind label %catch.dispatch
// catch.dispatch:
//   %0 = catchswitch within ... [label %catch.start] unwind label %next
// catch.start:
//   ...
//   ... in this BB or some other child BB dominated by this BB there will be an
//   invoke that points to 'next' BB as an unwind destination
//
// next: ; We don't need to add this to 'current' BB's successor
//   ...
static void findWasmUnwindDestinations(
    FunctionLoweringInfo &FuncInfo, const BasicBlock *EHPadBB,
    BranchProbability Prob,
    SmallVectorImpl<std::pair<MachineBasicBlock *, BranchProbability>>
        &UnwindDests) {}

/// When an invoke or a cleanupret unwinds to the next EH pad, there are
/// many places it could ultimately go. In the IR, we have a single unwind
/// destination, but in the machine CFG, we enumerate all the possible blocks.
/// This function skips over imaginary basic blocks that hold catchswitch
/// instructions, and finds all the "real" machine
/// basic block destinations. As those destinations may not be successors of
/// EHPadBB, here we also calculate the edge probability to those destinations.
/// The passed-in Prob is the edge probability to EHPadBB.
static void findUnwindDestinations(
    FunctionLoweringInfo &FuncInfo, const BasicBlock *EHPadBB,
    BranchProbability Prob,
    SmallVectorImpl<std::pair<MachineBasicBlock *, BranchProbability>>
        &UnwindDests) {}

void SelectionDAGBuilder::visitCleanupRet(const CleanupReturnInst &I) {}

void SelectionDAGBuilder::visitCatchSwitch(const CatchSwitchInst &CSI) {}

void SelectionDAGBuilder::visitRet(const ReturnInst &I) {}

/// CopyToExportRegsIfNeeded - If the given value has virtual registers
/// created for it, emit nodes to copy the value into the virtual
/// registers.
void SelectionDAGBuilder::CopyToExportRegsIfNeeded(const Value *V) {}

/// ExportFromCurrentBlock - If this condition isn't known to be exported from
/// the current basic block, add it to ValueMap now so that we'll get a
/// CopyTo/FromReg.
void SelectionDAGBuilder::ExportFromCurrentBlock(const Value *V) {}

bool SelectionDAGBuilder::isExportableFromCurrentBlock(const Value *V,
                                                     const BasicBlock *FromBB) {}

/// Return branch probability calculated by BranchProbabilityInfo for IR blocks.
BranchProbability
SelectionDAGBuilder::getEdgeProbability(const MachineBasicBlock *Src,
                                        const MachineBasicBlock *Dst) const {}

void SelectionDAGBuilder::addSuccessorWithProb(MachineBasicBlock *Src,
                                               MachineBasicBlock *Dst,
                                               BranchProbability Prob) {}

static bool InBlock(const Value *V, const BasicBlock *BB) {}

/// EmitBranchForMergedCondition - Helper method for FindMergedConditions.
/// This function emits a branch and is used at the leaves of an OR or an
/// AND operator tree.
void
SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond,
                                                  MachineBasicBlock *TBB,
                                                  MachineBasicBlock *FBB,
                                                  MachineBasicBlock *CurBB,
                                                  MachineBasicBlock *SwitchBB,
                                                  BranchProbability TProb,
                                                  BranchProbability FProb,
                                                  bool InvertCond) {}

// Collect dependencies on V recursively. This is used for the cost analysis in
// `shouldKeepJumpConditionsTogether`.
static bool collectInstructionDeps(
    SmallMapVector<const Instruction *, bool, 8> *Deps, const Value *V,
    SmallMapVector<const Instruction *, bool, 8> *Necessary = nullptr,
    unsigned Depth = 0) {}

bool SelectionDAGBuilder::shouldKeepJumpConditionsTogether(
    const FunctionLoweringInfo &FuncInfo, const BranchInst &I,
    Instruction::BinaryOps Opc, const Value *Lhs, const Value *Rhs,
    TargetLoweringBase::CondMergingParams Params) const {}

void SelectionDAGBuilder::FindMergedConditions(const Value *Cond,
                                               MachineBasicBlock *TBB,
                                               MachineBasicBlock *FBB,
                                               MachineBasicBlock *CurBB,
                                               MachineBasicBlock *SwitchBB,
                                               Instruction::BinaryOps Opc,
                                               BranchProbability TProb,
                                               BranchProbability FProb,
                                               bool InvertCond) {}

/// If the set of cases should be emitted as a series of branches, return true.
/// If we should emit this as a bunch of and/or'd together conditions, return
/// false.
bool
SelectionDAGBuilder::ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases) {}

void SelectionDAGBuilder::visitBr(const BranchInst &I) {}

/// visitSwitchCase - Emits the necessary code to represent a single node in
/// the binary search tree resulting from lowering a switch instruction.
void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB,
                                          MachineBasicBlock *SwitchBB) {}

/// visitJumpTable - Emit JumpTable node in the current MBB
void SelectionDAGBuilder::visitJumpTable(SwitchCG::JumpTable &JT) {}

/// visitJumpTableHeader - This function emits necessary code to produce index
/// in the JumpTable from switch case.
void SelectionDAGBuilder::visitJumpTableHeader(SwitchCG::JumpTable &JT,
                                               JumpTableHeader &JTH,
                                               MachineBasicBlock *SwitchBB) {}

/// Create a LOAD_STACK_GUARD node, and let it carry the target specific global
/// variable if there exists one.
static SDValue getLoadStackGuard(SelectionDAG &DAG, const SDLoc &DL,
                                 SDValue &Chain) {}

/// Codegen a new tail for a stack protector check ParentMBB which has had its
/// tail spliced into a stack protector check success bb.
///
/// For a high level explanation of how this fits into the stack protector
/// generation see the comment on the declaration of class
/// StackProtectorDescriptor.
void SelectionDAGBuilder::visitSPDescriptorParent(StackProtectorDescriptor &SPD,
                                                  MachineBasicBlock *ParentBB) {}

/// Codegen the failure basic block for a stack protector check.
///
/// A failure stack protector machine basic block consists simply of a call to
/// __stack_chk_fail().
///
/// For a high level explanation of how this fits into the stack protector
/// generation see the comment on the declaration of class
/// StackProtectorDescriptor.
void
SelectionDAGBuilder::visitSPDescriptorFailure(StackProtectorDescriptor &SPD) {}

/// visitBitTestHeader - This function emits necessary code to produce value
/// suitable for "bit tests"
void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
                                             MachineBasicBlock *SwitchBB) {}

/// visitBitTestCase - this function produces one "bit test"
void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB,
                                           MachineBasicBlock* NextMBB,
                                           BranchProbability BranchProbToNext,
                                           unsigned Reg,
                                           BitTestCase &B,
                                           MachineBasicBlock *SwitchBB) {}

void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {}

void SelectionDAGBuilder::visitCallBr(const CallBrInst &I) {}

void SelectionDAGBuilder::visitResume(const ResumeInst &RI) {}

void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &LP) {}

void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First,
                                           MachineBasicBlock *Last) {}

void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) {}

void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {}

void SelectionDAGBuilder::visitUnary(const User &I, unsigned Opcode) {}

void SelectionDAGBuilder::visitBinary(const User &I, unsigned Opcode) {}

void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) {}

void SelectionDAGBuilder::visitSDiv(const User &I) {}

void SelectionDAGBuilder::visitICmp(const ICmpInst &I) {}

void SelectionDAGBuilder::visitFCmp(const FCmpInst &I) {}

// Check if the condition of the select has one use or two users that are both
// selects with the same condition.
static bool hasOnlySelectUsers(const Value *Cond) {}

void SelectionDAGBuilder::visitSelect(const User &I) {}

void SelectionDAGBuilder::visitTrunc(const User &I) {}

void SelectionDAGBuilder::visitZExt(const User &I) {}

void SelectionDAGBuilder::visitSExt(const User &I) {}

void SelectionDAGBuilder::visitFPTrunc(const User &I) {}

void SelectionDAGBuilder::visitFPExt(const User &I) {}

void SelectionDAGBuilder::visitFPToUI(const User &I) {}

void SelectionDAGBuilder::visitFPToSI(const User &I) {}

void SelectionDAGBuilder::visitUIToFP(const User &I) {}

void SelectionDAGBuilder::visitSIToFP(const User &I) {}

void SelectionDAGBuilder::visitPtrToInt(const User &I) {}

void SelectionDAGBuilder::visitIntToPtr(const User &I) {}

void SelectionDAGBuilder::visitBitCast(const User &I) {}

void SelectionDAGBuilder::visitAddrSpaceCast(const User &I) {}

void SelectionDAGBuilder::visitInsertElement(const User &I) {}

void SelectionDAGBuilder::visitExtractElement(const User &I) {}

void SelectionDAGBuilder::visitShuffleVector(const User &I) {}

void SelectionDAGBuilder::visitInsertValue(const InsertValueInst &I) {}

void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) {}

void SelectionDAGBuilder::visitGetElementPtr(const User &I) {}

void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) {}

static const MDNode *getRangeMetadata(const Instruction &I) {}

static std::optional<ConstantRange> getRange(const Instruction &I) {}

void SelectionDAGBuilder::visitLoad(const LoadInst &I) {}

void SelectionDAGBuilder::visitStoreToSwiftError(const StoreInst &I) {}

void SelectionDAGBuilder::visitLoadFromSwiftError(const LoadInst &I) {}

void SelectionDAGBuilder::visitStore(const StoreInst &I) {}

void SelectionDAGBuilder::visitMaskedStore(const CallInst &I,
                                           bool IsCompressing) {}

// Get a uniform base for the Gather/Scatter intrinsic.
// The first argument of the Gather/Scatter intrinsic is a vector of pointers.
// We try to represent it as a base pointer + vector of indices.
// Usually, the vector of pointers comes from a 'getelementptr' instruction.
// The first operand of the GEP may be a single pointer or a vector of pointers
// Example:
//   %gep.ptr = getelementptr i32, <8 x i32*> %vptr, <8 x i32> %ind
//  or
//   %gep.ptr = getelementptr i32, i32* %ptr,        <8 x i32> %ind
// %res = call <8 x i32> @llvm.masked.gather.v8i32(<8 x i32*> %gep.ptr, ..
//
// When the first GEP operand is a single pointer - it is the uniform base we
// are looking for. If first operand of the GEP is a splat vector - we
// extract the splat value and use it as a uniform base.
// In all other cases the function returns 'false'.
static bool getUniformBase(const Value *Ptr, SDValue &Base, SDValue &Index,
                           ISD::MemIndexType &IndexType, SDValue &Scale,
                           SelectionDAGBuilder *SDB, const BasicBlock *CurBB,
                           uint64_t ElemSize) {}

void SelectionDAGBuilder::visitMaskedScatter(const CallInst &I) {}

void SelectionDAGBuilder::visitMaskedLoad(const CallInst &I, bool IsExpanding) {}

void SelectionDAGBuilder::visitMaskedGather(const CallInst &I) {}

void SelectionDAGBuilder::visitAtomicCmpXchg(const AtomicCmpXchgInst &I) {}

void SelectionDAGBuilder::visitAtomicRMW(const AtomicRMWInst &I) {}

void SelectionDAGBuilder::visitFence(const FenceInst &I) {}

void SelectionDAGBuilder::visitAtomicLoad(const LoadInst &I) {}

void SelectionDAGBuilder::visitAtomicStore(const StoreInst &I) {}

/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC
/// node.
void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I,
                                               unsigned Intrinsic) {}

/// GetSignificand - Get the significand and build it into a floating-point
/// number with exponent of 1:
///
///   Op = (Op & 0x007fffff) | 0x3f800000;
///
/// where Op is the hexadecimal representation of floating point value.
static SDValue GetSignificand(SelectionDAG &DAG, SDValue Op, const SDLoc &dl) {}

/// GetExponent - Get the exponent:
///
///   (float)(int)(((Op & 0x7f800000) >> 23) - 127);
///
/// where Op is the hexadecimal representation of floating point value.
static SDValue GetExponent(SelectionDAG &DAG, SDValue Op,
                           const TargetLowering &TLI, const SDLoc &dl) {}

/// getF32Constant - Get 32-bit floating point constant.
static SDValue getF32Constant(SelectionDAG &DAG, unsigned Flt,
                              const SDLoc &dl) {}

static SDValue getLimitedPrecisionExp2(SDValue t0, const SDLoc &dl,
                                       SelectionDAG &DAG) {}

/// expandExp - Lower an exp intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandExp(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
                         const TargetLowering &TLI, SDNodeFlags Flags) {}

/// expandLog - Lower a log intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
                         const TargetLowering &TLI, SDNodeFlags Flags) {}

/// expandLog2 - Lower a log2 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
                          const TargetLowering &TLI, SDNodeFlags Flags) {}

/// expandLog10 - Lower a log10 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog10(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
                           const TargetLowering &TLI, SDNodeFlags Flags) {}

/// expandExp2 - Lower an exp2 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandExp2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
                          const TargetLowering &TLI, SDNodeFlags Flags) {}

/// visitPow - Lower a pow intrinsic. Handles the special sequences for
/// limited-precision mode with x == 10.0f.
static SDValue expandPow(const SDLoc &dl, SDValue LHS, SDValue RHS,
                         SelectionDAG &DAG, const TargetLowering &TLI,
                         SDNodeFlags Flags) {}

/// ExpandPowI - Expand a llvm.powi intrinsic.
static SDValue ExpandPowI(const SDLoc &DL, SDValue LHS, SDValue RHS,
                          SelectionDAG &DAG) {}

static SDValue expandDivFix(unsigned Opcode, const SDLoc &DL,
                            SDValue LHS, SDValue RHS, SDValue Scale,
                            SelectionDAG &DAG, const TargetLowering &TLI) {}

// getUnderlyingArgRegs - Find underlying registers used for a truncated,
// bitcasted, or split argument. Returns a list of <Register, size in bits>
static void
getUnderlyingArgRegs(SmallVectorImpl<std::pair<unsigned, TypeSize>> &Regs,
                     const SDValue &N) {}

/// If the DbgValueInst is a dbg_value of a function argument, create the
/// corresponding DBG_VALUE machine instruction for it now.  At the end of
/// instruction selection, they will be inserted to the entry BB.
/// We don't currently support this for variadic dbg_values, as they shouldn't
/// appear for function arguments or in the prologue.
bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(
    const Value *V, DILocalVariable *Variable, DIExpression *Expr,
    DILocation *DL, FuncArgumentDbgValueKind Kind, const SDValue &N) {}

/// Return the appropriate SDDbgValue based on N.
SDDbgValue *SelectionDAGBuilder::getDbgValue(SDValue N,
                                             DILocalVariable *Variable,
                                             DIExpression *Expr,
                                             const DebugLoc &dl,
                                             unsigned DbgSDNodeOrder) {}

static unsigned FixedPointIntrinsicToOpcode(unsigned Intrinsic) {}

void SelectionDAGBuilder::lowerCallToExternalSymbol(const CallInst &I,
                                           const char *FunctionName) {}

/// Given a @llvm.call.preallocated.setup, return the corresponding
/// preallocated call.
static const CallBase *FindPreallocatedCall(const Value *PreallocatedSetup) {}

/// If DI is a debug value with an EntryValue expression, lower it using the
/// corresponding physical register of the associated Argument value
/// (guaranteed to exist by the verifier).
bool SelectionDAGBuilder::visitEntryValueDbgValue(
    ArrayRef<const Value *> Values, DILocalVariable *Variable,
    DIExpression *Expr, DebugLoc DbgLoc) {}

/// Lower the call to the specified intrinsic function.
void SelectionDAGBuilder::visitConvergenceControl(const CallInst &I,
                                                  unsigned Intrinsic) {}

void SelectionDAGBuilder::visitVectorHistogram(const CallInst &I,
                                               unsigned IntrinsicID) {}

/// Lower the call to the specified intrinsic function.
void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
                                             unsigned Intrinsic) {}

void SelectionDAGBuilder::visitConstrainedFPIntrinsic(
    const ConstrainedFPIntrinsic &FPI) {}

static unsigned getISDForVPIntrinsic(const VPIntrinsic &VPIntrin) {}

void SelectionDAGBuilder::visitVPLoad(
    const VPIntrinsic &VPIntrin, EVT VT,
    const SmallVectorImpl<SDValue> &OpValues) {}

void SelectionDAGBuilder::visitVPGather(
    const VPIntrinsic &VPIntrin, EVT VT,
    const SmallVectorImpl<SDValue> &OpValues) {}

void SelectionDAGBuilder::visitVPStore(
    const VPIntrinsic &VPIntrin, const SmallVectorImpl<SDValue> &OpValues) {}

void SelectionDAGBuilder::visitVPScatter(
    const VPIntrinsic &VPIntrin, const SmallVectorImpl<SDValue> &OpValues) {}

void SelectionDAGBuilder::visitVPStridedLoad(
    const VPIntrinsic &VPIntrin, EVT VT,
    const SmallVectorImpl<SDValue> &OpValues) {}

void SelectionDAGBuilder::visitVPStridedStore(
    const VPIntrinsic &VPIntrin, const SmallVectorImpl<SDValue> &OpValues) {}

void SelectionDAGBuilder::visitVPCmp(const VPCmpIntrinsic &VPIntrin) {}

void SelectionDAGBuilder::visitVectorPredicationIntrinsic(
    const VPIntrinsic &VPIntrin) {}

SDValue SelectionDAGBuilder::lowerStartEH(SDValue Chain,
                                          const BasicBlock *EHPadBB,
                                          MCSymbol *&BeginLabel) {}

SDValue SelectionDAGBuilder::lowerEndEH(SDValue Chain, const InvokeInst *II,
                                        const BasicBlock *EHPadBB,
                                        MCSymbol *BeginLabel) {}

std::pair<SDValue, SDValue>
SelectionDAGBuilder::lowerInvokable(TargetLowering::CallLoweringInfo &CLI,
                                    const BasicBlock *EHPadBB) {}

void SelectionDAGBuilder::LowerCallTo(const CallBase &CB, SDValue Callee,
                                      bool isTailCall, bool isMustTailCall,
                                      const BasicBlock *EHPadBB,
                                      const TargetLowering::PtrAuthInfo *PAI) {}

static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT,
                             SelectionDAGBuilder &Builder) {}

/// Record the value for an instruction that produces an integer result,
/// converting the type where necessary.
void SelectionDAGBuilder::processIntegerCallValue(const Instruction &I,
                                                  SDValue Value,
                                                  bool IsSigned) {}

/// See if we can lower a memcmp/bcmp call into an optimized form. If so, return
/// true and lower it. Otherwise return false, and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitMemCmpBCmpCall(const CallInst &I) {}

/// See if we can lower a memchr call into an optimized form. If so, return
/// true and lower it. Otherwise return false, and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitMemChrCall(const CallInst &I) {}

/// See if we can lower a mempcpy call into an optimized form. If so, return
/// true and lower it. Otherwise return false, and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitMemPCpyCall(const CallInst &I) {}

/// See if we can lower a strcpy call into an optimized form.  If so, return
/// true and lower it, otherwise return false and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitStrCpyCall(const CallInst &I, bool isStpcpy) {}

/// See if we can lower a strcmp call into an optimized form.  If so, return
/// true and lower it, otherwise return false and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitStrCmpCall(const CallInst &I) {}

/// See if we can lower a strlen call into an optimized form.  If so, return
/// true and lower it, otherwise return false and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitStrLenCall(const CallInst &I) {}

/// See if we can lower a strnlen call into an optimized form.  If so, return
/// true and lower it, otherwise return false and it will be lowered like a
/// normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitStrNLenCall(const CallInst &I) {}

/// See if we can lower a unary floating-point operation into an SDNode with
/// the specified Opcode.  If so, return true and lower it, otherwise return
/// false and it will be lowered like a normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitUnaryFloatCall(const CallInst &I,
                                              unsigned Opcode) {}

/// See if we can lower a binary floating-point operation into an SDNode with
/// the specified Opcode. If so, return true and lower it. Otherwise return
/// false, and it will be lowered like a normal call.
/// The caller already checked that \p I calls the appropriate LibFunc with a
/// correct prototype.
bool SelectionDAGBuilder::visitBinaryFloatCall(const CallInst &I,
                                               unsigned Opcode) {}

void SelectionDAGBuilder::visitCall(const CallInst &I) {}

void SelectionDAGBuilder::LowerCallSiteWithPtrAuthBundle(
    const CallBase &CB, const BasicBlock *EHPadBB) {}

namespace {

/// AsmOperandInfo - This contains information for each constraint that we are
/// lowering.
class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo {};


} // end anonymous namespace

/// Make sure that the output operand \p OpInfo and its corresponding input
/// operand \p MatchingOpInfo have compatible constraint types (otherwise error
/// out).
static void patchMatchingInput(const SDISelAsmOperandInfo &OpInfo,
                               SDISelAsmOperandInfo &MatchingOpInfo,
                               SelectionDAG &DAG) {}

/// Get a direct memory input to behave well as an indirect operand.
/// This may introduce stores, hence the need for a \p Chain.
/// \return The (possibly updated) chain.
static SDValue getAddressForMemoryInput(SDValue Chain, const SDLoc &Location,
                                        SDISelAsmOperandInfo &OpInfo,
                                        SelectionDAG &DAG) {}

/// GetRegistersForValue - Assign registers (virtual or physical) for the
/// specified operand.  We prefer to assign virtual registers, to allow the
/// register allocator to handle the assignment process.  However, if the asm
/// uses features that we can't model on machineinstrs, we have SDISel do the
/// allocation.  This produces generally horrible, but correct, code.
///
///   OpInfo describes the operand
///   RefOpInfo describes the matching operand if any, the operand otherwise
static std::optional<unsigned>
getRegistersForValue(SelectionDAG &DAG, const SDLoc &DL,
                     SDISelAsmOperandInfo &OpInfo,
                     SDISelAsmOperandInfo &RefOpInfo) {}

static unsigned
findMatchingInlineAsmOperand(unsigned OperandNo,
                             const std::vector<SDValue> &AsmNodeOperands) {}

namespace {

class ExtraFlags {};

} // end anonymous namespace

static bool isFunction(SDValue Op) {}

/// visitInlineAsm - Handle a call to an InlineAsm object.
void SelectionDAGBuilder::visitInlineAsm(const CallBase &Call,
                                         const BasicBlock *EHPadBB) {}

void SelectionDAGBuilder::emitInlineAsmError(const CallBase &Call,
                                             const Twine &Message) {}

void SelectionDAGBuilder::visitVAStart(const CallInst &I) {}

void SelectionDAGBuilder::visitVAArg(const VAArgInst &I) {}

void SelectionDAGBuilder::visitVAEnd(const CallInst &I) {}

void SelectionDAGBuilder::visitVACopy(const CallInst &I) {}

SDValue SelectionDAGBuilder::lowerRangeToAssertZExt(SelectionDAG &DAG,
                                                    const Instruction &I,
                                                    SDValue Op) {}

/// Populate a CallLowerinInfo (into \p CLI) based on the properties of
/// the call being lowered.
///
/// This is a helper for lowering intrinsics that follow a target calling
/// convention or require stack pointer adjustment. Only a subset of the
/// intrinsic's operands need to participate in the calling convention.
void SelectionDAGBuilder::populateCallLoweringInfo(
    TargetLowering::CallLoweringInfo &CLI, const CallBase *Call,
    unsigned ArgIdx, unsigned NumArgs, SDValue Callee, Type *ReturnTy,
    AttributeSet RetAttrs, bool IsPatchPoint) {}

/// Add a stack map intrinsic call's live variable operands to a stackmap
/// or patchpoint target node's operand list.
///
/// Constants are converted to TargetConstants purely as an optimization to
/// avoid constant materialization and register allocation.
///
/// FrameIndex operands are converted to TargetFrameIndex so that ISEL does not
/// generate addess computation nodes, and so FinalizeISel can convert the
/// TargetFrameIndex into a DirectMemRefOp StackMap location. This avoids
/// address materialization and register allocation, but may also be required
/// for correctness. If a StackMap (or PatchPoint) intrinsic directly uses an
/// alloca in the entry block, then the runtime may assume that the alloca's
/// StackMap location can be read immediately after compilation and that the
/// location is valid at any point during execution (this is similar to the
/// assumption made by the llvm.gcroot intrinsic). If the alloca's location were
/// only available in a register, then the runtime would need to trap when
/// execution reaches the StackMap in order to read the alloca's location.
static void addStackMapLiveVars(const CallBase &Call, unsigned StartIdx,
                                const SDLoc &DL, SmallVectorImpl<SDValue> &Ops,
                                SelectionDAGBuilder &Builder) {}

/// Lower llvm.experimental.stackmap.
void SelectionDAGBuilder::visitStackmap(const CallInst &CI) {}

/// Lower llvm.experimental.patchpoint directly to its target opcode.
void SelectionDAGBuilder::visitPatchpoint(const CallBase &CB,
                                          const BasicBlock *EHPadBB) {}

void SelectionDAGBuilder::visitVectorReduce(const CallInst &I,
                                            unsigned Intrinsic) {}

/// Returns an AttributeList representing the attributes applied to the return
/// value of the given call.
static AttributeList getReturnAttrs(TargetLowering::CallLoweringInfo &CLI) {}

/// TargetLowering::LowerCallTo - This is the default LowerCallTo
/// implementation, which just calls LowerCall.
/// FIXME: When all targets are
/// migrated to using LowerCall, this hook should be integrated into SDISel.
std::pair<SDValue, SDValue>
TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {}

/// Places new result values for the node in Results (their number
/// and types must exactly match those of the original return values of
/// the node), or leaves Results empty, which indicates that the node is not
/// to be custom lowered after all.
void TargetLowering::LowerOperationWrapper(SDNode *N,
                                           SmallVectorImpl<SDValue> &Results,
                                           SelectionDAG &DAG) const {}

SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {}

void SelectionDAGBuilder::CopyValueToVirtualRegister(const Value *V,
                                                     unsigned Reg,
                                                     ISD::NodeType ExtendType) {}

#include "llvm/CodeGen/SelectionDAGISel.h"

/// isOnlyUsedInEntryBlock - If the specified argument is only used in the
/// entry block, return true.  This includes arguments used by switches, since
/// the switch may expand into multiple basic blocks.
static bool isOnlyUsedInEntryBlock(const Argument *A, bool FastISel) {}

ArgCopyElisionMapTy;

/// Scan the entry block of the function in FuncInfo for arguments that look
/// like copies into a local alloca. Record any copied arguments in
/// ArgCopyElisionCandidates.
static void
findArgumentCopyElisionCandidates(const DataLayout &DL,
                                  FunctionLoweringInfo *FuncInfo,
                                  ArgCopyElisionMapTy &ArgCopyElisionCandidates) {}

/// Try to elide argument copies from memory into a local alloca. Succeeds if
/// ArgVal is a load from a suitable fixed stack object.
static void tryToElideArgumentCopy(
    FunctionLoweringInfo &FuncInfo, SmallVectorImpl<SDValue> &Chains,
    DenseMap<int, int> &ArgCopyElisionFrameIndexMap,
    SmallPtrSetImpl<const Instruction *> &ElidedArgCopyInstrs,
    ArgCopyElisionMapTy &ArgCopyElisionCandidates, const Argument &Arg,
    ArrayRef<SDValue> ArgVals, bool &ArgHasUses) {}

void SelectionDAGISel::LowerArguments(const Function &F) {}

/// Handle PHI nodes in successor blocks.  Emit code into the SelectionDAG to
/// ensure constants are generated when needed.  Remember the virtual registers
/// that need to be added to the Machine PHI nodes as input.  We cannot just
/// directly add them, because expansion might result in multiple MBB's for one
/// BB.  As such, the start of the BB might correspond to a different MBB than
/// the end.
void
SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {}

MachineBasicBlock *SelectionDAGBuilder::NextBlock(MachineBasicBlock *MBB) {}

/// During lowering new call nodes can be created (such as memset, etc.).
/// Those will become new roots of the current DAG, but complications arise
/// when they are tail calls. In such cases, the call lowering will update
/// the root, but the builder still needs to know that a tail call has been
/// lowered in order to avoid generating an additional return.
void SelectionDAGBuilder::updateDAGForMaybeTailCall(SDValue MaybeTC) {}

void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
                                        MachineBasicBlock *SwitchMBB,
                                        MachineBasicBlock *DefaultMBB) {}

void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList,
                                        const SwitchWorkListItem &W,
                                        Value *Cond,
                                        MachineBasicBlock *SwitchMBB) {}

// Scale CaseProb after peeling a case with the probablity of PeeledCaseProb
// from the swith statement.
static BranchProbability scaleCaseProbality(BranchProbability CaseProb,
                                            BranchProbability PeeledCaseProb) {}

// Try to peel the top probability case if it exceeds the threshold.
// Return current MachineBasicBlock for the switch statement if the peeling
// does not occur.
// If the peeling is performed, return the newly created MachineBasicBlock
// for the peeled switch statement. Also update Clusters to remove the peeled
// case. PeeledCaseProb is the BranchProbability for the peeled case.
MachineBasicBlock *SelectionDAGBuilder::peelDominantCaseCluster(
    const SwitchInst &SI, CaseClusterVector &Clusters,
    BranchProbability &PeeledCaseProb) {}

void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) {}

void SelectionDAGBuilder::visitStepVector(const CallInst &I) {}

void SelectionDAGBuilder::visitVectorReverse(const CallInst &I) {}

void SelectionDAGBuilder::visitVectorDeinterleave(const CallInst &I) {}

void SelectionDAGBuilder::visitVectorInterleave(const CallInst &I) {}

void SelectionDAGBuilder::visitFreeze(const FreezeInst &I) {}

void SelectionDAGBuilder::visitVectorSplice(const CallInst &I) {}

// Consider the following MIR after SelectionDAG, which produces output in
// phyregs in the first case or virtregs in the second case.
//
// INLINEASM_BR ..., implicit-def $ebx, ..., implicit-def $edx
// %5:gr32 = COPY $ebx
// %6:gr32 = COPY $edx
// %1:gr32 = COPY %6:gr32
// %0:gr32 = COPY %5:gr32
//
// INLINEASM_BR ..., def %5:gr32, ..., def %6:gr32
// %1:gr32 = COPY %6:gr32
// %0:gr32 = COPY %5:gr32
//
// Given %0, we'd like to return $ebx in the first case and %5 in the second.
// Given %1, we'd like to return $edx in the first case and %6 in the second.
//
// If a callbr has outputs, it will have a single mapping in FuncInfo.ValueMap
// to a single virtreg (such as %0). The remaining outputs monotonically
// increase in virtreg number from there. If a callbr has no outputs, then it
// should not have a corresponding callbr landingpad; in fact, the callbr
// landingpad would not even be able to refer to such a callbr.
static Register FollowCopyChain(MachineRegisterInfo &MRI, Register Reg) {}

// We must do this walk rather than the simpler
//   setValue(&I, getCopyFromRegs(CBR, CBR->getType()));
// otherwise we will end up with copies of virtregs only valid along direct
// edges.
void SelectionDAGBuilder::visitCallBrLandingPad(const CallInst &I) {}