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//===- SelectionDAGBuilder.h - Selection-DAG building -----------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This implements routines for translating from LLVM IR into SelectionDAG IR.
#include "StatepointLowering.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/AssignmentTrackingAnalysis.h"
#include "llvm/CodeGen/CodeGenCommonISel.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineValueType.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/SwitchLoweringUtils.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Instruction.h"
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/ErrorHandling.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <optional>
#include <utility>
#include <vector>
namespace llvm {
class AAResults;
class AllocaInst;
class AtomicCmpXchgInst;
class AtomicRMWInst;
class AssumptionCache;
class BasicBlock;
class BranchInst;
class CallInst;
class CallBrInst;
class CatchPadInst;
class CatchReturnInst;
class CatchSwitchInst;
class CleanupPadInst;
class CleanupReturnInst;
class Constant;
class ConstrainedFPIntrinsic;
class DbgValueInst;
class DataLayout;
class DIExpression;
class DILocalVariable;
class DILocation;
class FenceInst;
class FunctionLoweringInfo;
class GCFunctionInfo;
class GCRelocateInst;
class GCResultInst;
class GCStatepointInst;
class IndirectBrInst;
class InvokeInst;
class LandingPadInst;
class LLVMContext;
class LoadInst;
class MachineBasicBlock;
class PHINode;
class ResumeInst;
class ReturnInst;
class SDDbgValue;
class SelectionDAG;
class StoreInst;
class SwiftErrorValueTracking;
class SwitchInst;
class TargetLibraryInfo;
class TargetMachine;
class Type;
class VAArgInst;
class UnreachableInst;
class Use;
class User;
class Value;
/// SelectionDAGBuilder - This is the common target-independent lowering
/// implementation that is parameterized by a TargetLowering object.
class SelectionDAGBuilder {
/// The current instruction being visited.
const Instruction *CurInst = nullptr;
DenseMap<const Value*, SDValue> NodeMap;
/// Maps argument value for unused arguments. This is used
/// to preserve debug information for incoming arguments.
DenseMap<const Value*, SDValue> UnusedArgNodeMap;
/// Helper type for DanglingDebugInfoMap.
class DanglingDebugInfo {
using DbgValTy = const DbgValueInst *;
using VarLocTy = const VarLocInfo *;
PointerUnion<DbgValTy, VarLocTy> Info;
unsigned SDNodeOrder = 0;
DanglingDebugInfo() = default;
DanglingDebugInfo(const DbgValueInst *DI, unsigned SDNO)
: Info(DI), SDNodeOrder(SDNO) {}
DanglingDebugInfo(const VarLocInfo *VarLoc, unsigned SDNO)
: Info(VarLoc), SDNodeOrder(SDNO) {}
DILocalVariable *getVariable(const FunctionVarLocs *Locs) const {
if (isa<VarLocTy>(Info))
return Locs->getDILocalVariable(cast<VarLocTy>(Info)->VariableID);
return cast<DbgValTy>(Info)->getVariable();
DIExpression *getExpression() const {
if (isa<VarLocTy>(Info))
return cast<VarLocTy>(Info)->Expr;
return cast<DbgValTy>(Info)->getExpression();
Value *getVariableLocationOp(unsigned Idx) const {
assert(Idx == 0 && "Dangling variadic debug values not supported yet");
if (isa<VarLocTy>(Info))
return cast<VarLocTy>(Info)->Values.getVariableLocationOp(Idx);
return cast<DbgValTy>(Info)->getVariableLocationOp(Idx);
DebugLoc getDebugLoc() const {
if (isa<VarLocTy>(Info))
return cast<VarLocTy>(Info)->DL;
return cast<DbgValTy>(Info)->getDebugLoc();
unsigned getSDNodeOrder() const { return SDNodeOrder; }
/// Helper for printing DanglingDebugInfo. This hoop-jumping is to
/// accommodate the fact that an argument is required for getVariable.
/// Call SelectionDAGBuilder::printDDI instead of using directly.
struct Print {
Print(const DanglingDebugInfo &DDI, const FunctionVarLocs *VarLocs)
: DDI(DDI), VarLocs(VarLocs) {}
const DanglingDebugInfo &DDI;
const FunctionVarLocs *VarLocs;
friend raw_ostream &operator<<(raw_ostream &OS,
const DanglingDebugInfo::Print &P) {
OS << "DDI(var=" << *P.DDI.getVariable(P.VarLocs)
<< ", val= " << *P.DDI.getVariableLocationOp(0)
<< ", expr=" << *P.DDI.getExpression()
<< ", order=" << P.DDI.getSDNodeOrder()
<< ", loc=" << P.DDI.getDebugLoc() << ")";
return OS;
/// Returns an object that defines `raw_ostream &operator<<` for printing.
/// Usage example:
//// errs() << printDDI(MyDanglingInfo) << " is dangling\n";
DanglingDebugInfo::Print printDDI(const DanglingDebugInfo &DDI) {
return DanglingDebugInfo::Print(DDI, DAG.getFunctionVarLocs());
/// Helper type for DanglingDebugInfoMap.
typedef std::vector<DanglingDebugInfo> DanglingDebugInfoVector;
/// Keeps track of dbg_values for which we have not yet seen the referent.
/// We defer handling these until we do see it.
MapVector<const Value*, DanglingDebugInfoVector> DanglingDebugInfoMap;
/// Cache the module flag for whether we should use debug-info assignment
/// tracking.
bool AssignmentTrackingEnabled = false;
/// Loads are not emitted to the program immediately. We bunch them up and
/// then emit token factor nodes when possible. This allows us to get simple
/// disambiguation between loads without worrying about alias analysis.
SmallVector<SDValue, 8> PendingLoads;
/// State used while lowering a statepoint sequence (gc_statepoint,
/// gc_relocate, and gc_result). See StatepointLowering.hpp/cpp for details.
StatepointLoweringState StatepointLowering;
/// CopyToReg nodes that copy values to virtual registers for export to other
/// blocks need to be emitted before any terminator instruction, but they have
/// no other ordering requirements. We bunch them up and the emit a single
/// tokenfactor for them just before terminator instructions.
SmallVector<SDValue, 8> PendingExports;
/// Similar to loads, nodes corresponding to constrained FP intrinsics are
/// bunched up and emitted when necessary. These can be moved across each
/// other and any (normal) memory operation (load or store), but not across
/// calls or instructions having unspecified side effects. As a special
/// case, constrained FP intrinsics using fpexcept.strict may not be deleted
/// even if otherwise unused, so they need to be chained before any
/// terminator instruction (like PendingExports). We track the latter
/// set of nodes in a separate list.
SmallVector<SDValue, 8> PendingConstrainedFP;
SmallVector<SDValue, 8> PendingConstrainedFPStrict;
/// Update root to include all chains from the Pending list.
SDValue updateRoot(SmallVectorImpl<SDValue> &Pending);
/// A unique monotonically increasing number used to order the SDNodes we
/// create.
unsigned SDNodeOrder;
/// Determine the rank by weight of CC in [First,Last]. If CC has more weight
/// than each cluster in the range, its rank is 0.
unsigned caseClusterRank(const SwitchCG::CaseCluster &CC,
SwitchCG::CaseClusterIt First,
SwitchCG::CaseClusterIt Last);
/// Emit comparison and split W into two subtrees.
void splitWorkItem(SwitchCG::SwitchWorkList &WorkList,
const SwitchCG::SwitchWorkListItem &W, Value *Cond,
MachineBasicBlock *SwitchMBB);
/// Lower W.
void lowerWorkItem(SwitchCG::SwitchWorkListItem W, Value *Cond,
MachineBasicBlock *SwitchMBB,
MachineBasicBlock *DefaultMBB);
/// Peel the top probability case if it exceeds the threshold
MachineBasicBlock *
peelDominantCaseCluster(const SwitchInst &SI,
SwitchCG::CaseClusterVector &Clusters,
BranchProbability &PeeledCaseProb);
const TargetMachine &TM;
/// Lowest valid SDNodeOrder. The special case 0 is reserved for scheduling
/// nodes without a corresponding SDNode.
static const unsigned LowestSDNodeOrder = 1;
SelectionDAG &DAG;
AAResults *AA = nullptr;
AssumptionCache *AC = nullptr;
const TargetLibraryInfo *LibInfo = nullptr;
class SDAGSwitchLowering : public SwitchCG::SwitchLowering {
SDAGSwitchLowering(SelectionDAGBuilder *sdb, FunctionLoweringInfo &funcinfo)
: SwitchCG::SwitchLowering(funcinfo), SDB(sdb) {}
void addSuccessorWithProb(
MachineBasicBlock *Src, MachineBasicBlock *Dst,
BranchProbability Prob = BranchProbability::getUnknown()) override {
SDB->addSuccessorWithProb(Src, Dst, Prob);
SelectionDAGBuilder *SDB = nullptr;
// Data related to deferred switch lowerings. Used to construct additional
// Basic Blocks in SelectionDAGISel::FinishBasicBlock.
std::unique_ptr<SDAGSwitchLowering> SL;
/// A StackProtectorDescriptor structure used to communicate stack protector
/// information in between SelectBasicBlock and FinishBasicBlock.
StackProtectorDescriptor SPDescriptor;
// Emit PHI-node-operand constants only once even if used by multiple
// PHI nodes.
DenseMap<const Constant *, unsigned> ConstantsOut;
/// Information about the function as a whole.
FunctionLoweringInfo &FuncInfo;
/// Information about the swifterror values used throughout the function.
SwiftErrorValueTracking &SwiftError;
/// Garbage collection metadata for the function.
GCFunctionInfo *GFI = nullptr;
/// Map a landing pad to the call site indexes.
DenseMap<MachineBasicBlock *, SmallVector<unsigned, 4>> LPadToCallSiteMap;
/// This is set to true if a call in the current block has been translated as
/// a tail call. In this case, no subsequent DAG nodes should be created.
bool HasTailCall = false;
LLVMContext *Context = nullptr;
SelectionDAGBuilder(SelectionDAG &dag, FunctionLoweringInfo &funcinfo,
SwiftErrorValueTracking &swifterror, CodeGenOpt::Level ol)
: SDNodeOrder(LowestSDNodeOrder), TM(dag.getTarget()), DAG(dag),
SL(std::make_unique<SDAGSwitchLowering>(this, funcinfo)), FuncInfo(funcinfo),
SwiftError(swifterror) {}
void init(GCFunctionInfo *gfi, AAResults *AA, AssumptionCache *AC,
const TargetLibraryInfo *li);
/// Clear out the current SelectionDAG and the associated state and prepare
/// this SelectionDAGBuilder object to be used for a new block. This doesn't
/// clear out information about additional blocks that are needed to complete
/// switch lowering or PHI node updating; that information is cleared out as
/// it is consumed.
void clear();
/// Clear the dangling debug information map. This function is separated from
/// the clear so that debug information that is dangling in a basic block can
/// be properly resolved in a different basic block. This allows the
/// SelectionDAG to resolve dangling debug information attached to PHI nodes.
void clearDanglingDebugInfo();
/// Return the current virtual root of the Selection DAG, flushing any
/// PendingLoad items. This must be done before emitting a store or any other
/// memory node that may need to be ordered after any prior load instructions.
SDValue getMemoryRoot();
/// Similar to getMemoryRoot, but also flushes PendingConstrainedFP(Strict)
/// items. This must be done before emitting any call other any other node
/// that may need to be ordered after FP instructions due to other side
/// effects.
SDValue getRoot();
/// Similar to getRoot, but instead of flushing all the PendingLoad items,
/// flush all the PendingExports (and PendingConstrainedFPStrict) items.
/// It is necessary to do this before emitting a terminator instruction.
SDValue getControlRoot();
SDLoc getCurSDLoc() const {
return SDLoc(CurInst, SDNodeOrder);
DebugLoc getCurDebugLoc() const {
return CurInst ? CurInst->getDebugLoc() : DebugLoc();
void CopyValueToVirtualRegister(const Value *V, unsigned Reg,
ISD::NodeType ExtendType = ISD::ANY_EXTEND);
void visit(const Instruction &I);
void visit(unsigned Opcode, const User &I);
/// If there was virtual register allocated for the value V emit CopyFromReg
/// of the specified type Ty. Return empty SDValue() otherwise.
SDValue getCopyFromRegs(const Value *V, Type *Ty);
/// Register a dbg_value which relies on a Value which we have not yet seen.
void addDanglingDebugInfo(const DbgValueInst *DI, unsigned Order);
void addDanglingDebugInfo(const VarLocInfo *VarLoc, unsigned Order);
/// If we have dangling debug info that describes \p Variable, or an
/// overlapping part of variable considering the \p Expr, then this method
/// will drop that debug info as it isn't valid any longer.
void dropDanglingDebugInfo(const DILocalVariable *Variable,
const DIExpression *Expr);
/// If we saw an earlier dbg_value referring to V, generate the debug data
/// structures now that we've seen its definition.
void resolveDanglingDebugInfo(const Value *V, SDValue Val);
/// For the given dangling debuginfo record, perform last-ditch efforts to
/// resolve the debuginfo to something that is represented in this DAG. If
/// this cannot be done, produce an Undef debug value record.
void salvageUnresolvedDbgValue(DanglingDebugInfo &DDI);
/// For a given list of Values, attempt to create and record a SDDbgValue in
/// the SelectionDAG.
bool handleDebugValue(ArrayRef<const Value *> Values, DILocalVariable *Var,
DIExpression *Expr, DebugLoc DbgLoc, unsigned Order,
bool IsVariadic);
/// Create a record for a kill location debug intrinsic.
void handleKillDebugValue(DILocalVariable *Var, DIExpression *Expr,
DebugLoc DbgLoc, unsigned Order);
/// Evict any dangling debug information, attempting to salvage it first.
void resolveOrClearDbgInfo();
SDValue getValue(const Value *V);
SDValue getNonRegisterValue(const Value *V);
SDValue getValueImpl(const Value *V);
void setValue(const Value *V, SDValue NewN) {
SDValue &N = NodeMap[V];
assert(!N.getNode() && "Already set a value for this node!");
N = NewN;
void setUnusedArgValue(const Value *V, SDValue NewN) {
SDValue &N = UnusedArgNodeMap[V];
assert(!N.getNode() && "Already set a value for this node!");
N = NewN;
void FindMergedConditions(const Value *Cond, MachineBasicBlock *TBB,
MachineBasicBlock *FBB, MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
Instruction::BinaryOps Opc, BranchProbability TProb,
BranchProbability FProb, bool InvertCond);
void EmitBranchForMergedCondition(const Value *Cond, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
BranchProbability TProb, BranchProbability FProb,
bool InvertCond);
bool ShouldEmitAsBranches(const std::vector<SwitchCG::CaseBlock> &Cases);
bool isExportableFromCurrentBlock(const Value *V, const BasicBlock *FromBB);
void CopyToExportRegsIfNeeded(const Value *V);
void ExportFromCurrentBlock(const Value *V);
void LowerCallTo(const CallBase &CB, SDValue Callee, bool IsTailCall,
bool IsMustTailCall, const BasicBlock *EHPadBB = nullptr);
// Lower range metadata from 0 to N to assert zext to an integer of nearest
// floor power of two.
SDValue lowerRangeToAssertZExt(SelectionDAG &DAG, const Instruction &I,
SDValue Op);
void populateCallLoweringInfo(TargetLowering::CallLoweringInfo &CLI,
const CallBase *Call, unsigned ArgIdx,
unsigned NumArgs, SDValue Callee,
Type *ReturnTy, bool IsPatchPoint);
std::pair<SDValue, SDValue>
lowerInvokable(TargetLowering::CallLoweringInfo &CLI,
const BasicBlock *EHPadBB = nullptr);
/// When an MBB was split during scheduling, update the
/// references that need to refer to the last resulting block.
void UpdateSplitBlock(MachineBasicBlock *First, MachineBasicBlock *Last);
/// Describes a gc.statepoint or a gc.statepoint like thing for the purposes
/// of lowering into a STATEPOINT node.
struct StatepointLoweringInfo {
/// Bases[i] is the base pointer for Ptrs[i]. Together they denote the set
/// of gc pointers this STATEPOINT has to relocate.
SmallVector<const Value *, 16> Bases;
SmallVector<const Value *, 16> Ptrs;
/// The set of gc.relocate calls associated with this gc.statepoint.
SmallVector<const GCRelocateInst *, 16> GCRelocates;
/// The full list of gc arguments to the gc.statepoint being lowered.
ArrayRef<const Use> GCArgs;
/// The gc.statepoint instruction.
const Instruction *StatepointInstr = nullptr;
/// The list of gc transition arguments present in the gc.statepoint being
/// lowered.
ArrayRef<const Use> GCTransitionArgs;
/// The ID that the resulting STATEPOINT instruction has to report.
unsigned ID = -1;
/// Information regarding the underlying call instruction.
TargetLowering::CallLoweringInfo CLI;
/// The deoptimization state associated with this gc.statepoint call, if
/// any.
ArrayRef<const Use> DeoptState;
/// Flags associated with the meta arguments being lowered.
uint64_t StatepointFlags = -1;
/// The number of patchable bytes the call needs to get lowered into.
unsigned NumPatchBytes = -1;
/// The exception handling unwind destination, in case this represents an
/// invoke of gc.statepoint.
const BasicBlock *EHPadBB = nullptr;
explicit StatepointLoweringInfo(SelectionDAG &DAG) : CLI(DAG) {}
/// Lower \p SLI into a STATEPOINT instruction.
SDValue LowerAsSTATEPOINT(StatepointLoweringInfo &SI);
// This function is responsible for the whole statepoint lowering process.
// It uniformly handles invoke and call statepoints.
void LowerStatepoint(const GCStatepointInst &I,
const BasicBlock *EHPadBB = nullptr);
void LowerCallSiteWithDeoptBundle(const CallBase *Call, SDValue Callee,
const BasicBlock *EHPadBB);
void LowerDeoptimizeCall(const CallInst *CI);
void LowerDeoptimizingReturn();
void LowerCallSiteWithDeoptBundleImpl(const CallBase *Call, SDValue Callee,
const BasicBlock *EHPadBB,
bool VarArgDisallowed,
bool ForceVoidReturnTy);
/// Returns the type of FrameIndex and TargetFrameIndex nodes.
MVT getFrameIndexTy() {
return DAG.getTargetLoweringInfo().getFrameIndexTy(DAG.getDataLayout());
// Terminator instructions.
void visitRet(const ReturnInst &I);
void visitBr(const BranchInst &I);
void visitSwitch(const SwitchInst &I);
void visitIndirectBr(const IndirectBrInst &I);
void visitUnreachable(const UnreachableInst &I);
void visitCleanupRet(const CleanupReturnInst &I);
void visitCatchSwitch(const CatchSwitchInst &I);
void visitCatchRet(const CatchReturnInst &I);
void visitCatchPad(const CatchPadInst &I);
void visitCleanupPad(const CleanupPadInst &CPI);
BranchProbability getEdgeProbability(const MachineBasicBlock *Src,
const MachineBasicBlock *Dst) const;
void addSuccessorWithProb(
MachineBasicBlock *Src, MachineBasicBlock *Dst,
BranchProbability Prob = BranchProbability::getUnknown());
void visitSwitchCase(SwitchCG::CaseBlock &CB, MachineBasicBlock *SwitchBB);
void visitSPDescriptorParent(StackProtectorDescriptor &SPD,
MachineBasicBlock *ParentBB);
void visitSPDescriptorFailure(StackProtectorDescriptor &SPD);
void visitBitTestHeader(SwitchCG::BitTestBlock &B,
MachineBasicBlock *SwitchBB);
void visitBitTestCase(SwitchCG::BitTestBlock &BB, MachineBasicBlock *NextMBB,
BranchProbability BranchProbToNext, unsigned Reg,
SwitchCG::BitTestCase &B, MachineBasicBlock *SwitchBB);
void visitJumpTable(SwitchCG::JumpTable &JT);
void visitJumpTableHeader(SwitchCG::JumpTable &JT,
SwitchCG::JumpTableHeader &JTH,
MachineBasicBlock *SwitchBB);
// These all get lowered before this pass.
void visitInvoke(const InvokeInst &I);
void visitCallBr(const CallBrInst &I);
void visitCallBrLandingPad(const CallInst &I);
void visitResume(const ResumeInst &I);
void visitUnary(const User &I, unsigned Opcode);
void visitFNeg(const User &I) { visitUnary(I, ISD::FNEG); }
void visitBinary(const User &I, unsigned Opcode);
void visitShift(const User &I, unsigned Opcode);
void visitAdd(const User &I) { visitBinary(I, ISD::ADD); }
void visitFAdd(const User &I) { visitBinary(I, ISD::FADD); }
void visitSub(const User &I) { visitBinary(I, ISD::SUB); }
void visitFSub(const User &I) { visitBinary(I, ISD::FSUB); }
void visitMul(const User &I) { visitBinary(I, ISD::MUL); }
void visitFMul(const User &I) { visitBinary(I, ISD::FMUL); }
void visitURem(const User &I) { visitBinary(I, ISD::UREM); }
void visitSRem(const User &I) { visitBinary(I, ISD::SREM); }
void visitFRem(const User &I) { visitBinary(I, ISD::FREM); }
void visitUDiv(const User &I) { visitBinary(I, ISD::UDIV); }
void visitSDiv(const User &I);
void visitFDiv(const User &I) { visitBinary(I, ISD::FDIV); }
void visitAnd (const User &I) { visitBinary(I, ISD::AND); }
void visitOr (const User &I) { visitBinary(I, ISD::OR); }
void visitXor (const User &I) { visitBinary(I, ISD::XOR); }
void visitShl (const User &I) { visitShift(I, ISD::SHL); }
void visitLShr(const User &I) { visitShift(I, ISD::SRL); }
void visitAShr(const User &I) { visitShift(I, ISD::SRA); }
void visitICmp(const User &I);
void visitFCmp(const User &I);
// Visit the conversion instructions
void visitTrunc(const User &I);
void visitZExt(const User &I);
void visitSExt(const User &I);
void visitFPTrunc(const User &I);
void visitFPExt(const User &I);
void visitFPToUI(const User &I);
void visitFPToSI(const User &I);
void visitUIToFP(const User &I);
void visitSIToFP(const User &I);
void visitPtrToInt(const User &I);
void visitIntToPtr(const User &I);
void visitBitCast(const User &I);
void visitAddrSpaceCast(const User &I);
void visitExtractElement(const User &I);
void visitInsertElement(const User &I);
void visitShuffleVector(const User &I);
void visitExtractValue(const ExtractValueInst &I);
void visitInsertValue(const InsertValueInst &I);
void visitLandingPad(const LandingPadInst &LP);
void visitGetElementPtr(const User &I);
void visitSelect(const User &I);
void visitAlloca(const AllocaInst &I);
void visitLoad(const LoadInst &I);
void visitStore(const StoreInst &I);
void visitMaskedLoad(const CallInst &I, bool IsExpanding = false);
void visitMaskedStore(const CallInst &I, bool IsCompressing = false);
void visitMaskedGather(const CallInst &I);
void visitMaskedScatter(const CallInst &I);
void visitAtomicCmpXchg(const AtomicCmpXchgInst &I);
void visitAtomicRMW(const AtomicRMWInst &I);
void visitFence(const FenceInst &I);
void visitPHI(const PHINode &I);
void visitCall(const CallInst &I);
bool visitMemCmpBCmpCall(const CallInst &I);
bool visitMemPCpyCall(const CallInst &I);
bool visitMemChrCall(const CallInst &I);
bool visitStrCpyCall(const CallInst &I, bool isStpcpy);
bool visitStrCmpCall(const CallInst &I);
bool visitStrLenCall(const CallInst &I);
bool visitStrNLenCall(const CallInst &I);
bool visitUnaryFloatCall(const CallInst &I, unsigned Opcode);
bool visitBinaryFloatCall(const CallInst &I, unsigned Opcode);
void visitAtomicLoad(const LoadInst &I);
void visitAtomicStore(const StoreInst &I);
void visitLoadFromSwiftError(const LoadInst &I);
void visitStoreToSwiftError(const StoreInst &I);
void visitFreeze(const FreezeInst &I);
void visitInlineAsm(const CallBase &Call,
const BasicBlock *EHPadBB = nullptr);
void visitIntrinsicCall(const CallInst &I, unsigned Intrinsic);
void visitTargetIntrinsic(const CallInst &I, unsigned Intrinsic);
void visitConstrainedFPIntrinsic(const ConstrainedFPIntrinsic &FPI);
void visitVPLoad(const VPIntrinsic &VPIntrin, EVT VT,
const SmallVectorImpl<SDValue> &OpValues);
void visitVPStore(const VPIntrinsic &VPIntrin,
const SmallVectorImpl<SDValue> &OpValues);
void visitVPGather(const VPIntrinsic &VPIntrin, EVT VT,
const SmallVectorImpl<SDValue> &OpValues);
void visitVPScatter(const VPIntrinsic &VPIntrin,
const SmallVectorImpl<SDValue> &OpValues);
void visitVPStridedLoad(const VPIntrinsic &VPIntrin, EVT VT,
const SmallVectorImpl<SDValue> &OpValues);
void visitVPStridedStore(const VPIntrinsic &VPIntrin,
const SmallVectorImpl<SDValue> &OpValues);
void visitVPCmp(const VPCmpIntrinsic &VPIntrin);
void visitVectorPredicationIntrinsic(const VPIntrinsic &VPIntrin);
void visitVAStart(const CallInst &I);
void visitVAArg(const VAArgInst &I);
void visitVAEnd(const CallInst &I);
void visitVACopy(const CallInst &I);
void visitStackmap(const CallInst &I);
void visitPatchpoint(const CallBase &CB, const BasicBlock *EHPadBB = nullptr);
// These two are implemented in StatepointLowering.cpp
void visitGCRelocate(const GCRelocateInst &Relocate);
void visitGCResult(const GCResultInst &I);
void visitVectorReduce(const CallInst &I, unsigned Intrinsic);
void visitVectorReverse(const CallInst &I);
void visitVectorSplice(const CallInst &I);
void visitVectorInterleave(const CallInst &I);
void visitVectorDeinterleave(const CallInst &I);
void visitStepVector(const CallInst &I);
void visitUserOp1(const Instruction &I) {
llvm_unreachable("UserOp1 should not exist at instruction selection time!");
void visitUserOp2(const Instruction &I) {
llvm_unreachable("UserOp2 should not exist at instruction selection time!");
void processIntegerCallValue(const Instruction &I,
SDValue Value, bool IsSigned);
void HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB);
void emitInlineAsmError(const CallBase &Call, const Twine &Message);
/// An enum that states to emit func argument dbg value the kind of intrinsic
/// it originally had. This controls the internal behavior of
/// EmitFuncArgumentDbgValue.
enum class FuncArgumentDbgValueKind {
Value, // This was originally a llvm.dbg.value.
Declare, // This was originally a llvm.dbg.declare.
/// If V is an function argument then create corresponding DBG_VALUE machine
/// instruction for it now. At the end of instruction selection, they will be
/// inserted to the entry BB.
bool EmitFuncArgumentDbgValue(const Value *V, DILocalVariable *Variable,
DIExpression *Expr, DILocation *DL,
FuncArgumentDbgValueKind Kind,
const SDValue &N);
/// Return the next block after MBB, or nullptr if there is none.
MachineBasicBlock *NextBlock(MachineBasicBlock *MBB);
/// Update the DAG and DAG builder with the relevant information after
/// a new root node has been created which could be a tail call.
void updateDAGForMaybeTailCall(SDValue MaybeTC);
/// Return the appropriate SDDbgValue based on N.
SDDbgValue *getDbgValue(SDValue N, DILocalVariable *Variable,
DIExpression *Expr, const DebugLoc &dl,
unsigned DbgSDNodeOrder);
/// Lowers CallInst to an external symbol.
void lowerCallToExternalSymbol(const CallInst &I, const char *FunctionName);
SDValue lowerStartEH(SDValue Chain, const BasicBlock *EHPadBB,
MCSymbol *&BeginLabel);
SDValue lowerEndEH(SDValue Chain, const InvokeInst *II,
const BasicBlock *EHPadBB, MCSymbol *BeginLabel);
/// This struct represents the registers (physical or virtual)
/// that a particular set of values is assigned, and the type information about
/// the value. The most common situation is to represent one value at a time,
/// but struct or array values are handled element-wise as multiple values. The
/// splitting of aggregates is performed recursively, so that we never have
/// aggregate-typed registers. The values at this point do not necessarily have
/// legal types, so each value may require one or more registers of some legal
/// type.
struct RegsForValue {
/// The value types of the values, which may not be legal, and
/// may need be promoted or synthesized from one or more registers.
SmallVector<EVT, 4> ValueVTs;
/// The value types of the registers. This is the same size as ValueVTs and it
/// records, for each value, what the type of the assigned register or
/// registers are. (Individual values are never synthesized from more than one
/// type of register.)
/// With virtual registers, the contents of RegVTs is redundant with TLI's
/// getRegisterType member function, however when with physical registers
/// it is necessary to have a separate record of the types.
SmallVector<MVT, 4> RegVTs;
/// This list holds the registers assigned to the values.
/// Each legal or promoted value requires one register, and each
/// expanded value requires multiple registers.
SmallVector<unsigned, 4> Regs;
/// This list holds the number of registers for each value.
SmallVector<unsigned, 4> RegCount;
/// Records if this value needs to be treated in an ABI dependant manner,
/// different to normal type legalization.
std::optional<CallingConv::ID> CallConv;
RegsForValue() = default;
RegsForValue(const SmallVector<unsigned, 4> &regs, MVT regvt, EVT valuevt,
std::optional<CallingConv::ID> CC = std::nullopt);
RegsForValue(LLVMContext &Context, const TargetLowering &TLI,
const DataLayout &DL, unsigned Reg, Type *Ty,
std::optional<CallingConv::ID> CC);
bool isABIMangled() const { return CallConv.has_value(); }
/// Add the specified values to this one.
void append(const RegsForValue &RHS) {
ValueVTs.append(RHS.ValueVTs.begin(), RHS.ValueVTs.end());
RegVTs.append(RHS.RegVTs.begin(), RHS.RegVTs.end());
Regs.append(RHS.Regs.begin(), RHS.Regs.end());
/// Emit a series of CopyFromReg nodes that copies from this value and returns
/// the result as a ValueVTs value. This uses Chain/Flag as the input and
/// updates them for the output Chain/Flag. If the Flag pointer is NULL, no
/// flag is used.
SDValue getCopyFromRegs(SelectionDAG &DAG, FunctionLoweringInfo &FuncInfo,
const SDLoc &dl, SDValue &Chain, SDValue *Glue,
const Value *V = nullptr) const;
/// Emit a series of CopyToReg nodes that copies the specified value into the
/// registers specified by this object. This uses Chain/Flag as the input and
/// updates them for the output Chain/Flag. If the Flag pointer is nullptr, no
/// flag is used. If V is not nullptr, then it is used in printing better
/// diagnostic messages on error.
void getCopyToRegs(SDValue Val, SelectionDAG &DAG, const SDLoc &dl,
SDValue &Chain, SDValue *Glue, const Value *V = nullptr,
ISD::NodeType PreferredExtendType = ISD::ANY_EXTEND) const;
/// Add this value to the specified inlineasm node operand list. This adds the
/// code marker, matching input operand index (if applicable), and includes
/// the number of values added into it.
void AddInlineAsmOperands(unsigned Code, bool HasMatching,
unsigned MatchingIdx, const SDLoc &dl,
SelectionDAG &DAG, std::vector<SDValue> &Ops) const;
/// Check if the total RegCount is greater than one.
bool occupiesMultipleRegs() const {
return std::accumulate(RegCount.begin(), RegCount.end(), 0) > 1;
/// Return a list of registers and their sizes.
SmallVector<std::pair<unsigned, TypeSize>, 4> getRegsAndSizes() const;
} // end namespace llvm