[CallSite removal][TargetLowering] Replace ImmutableCallSite with CallBase

[craig.topper]

Use auto in place of ImmutableCallSite::arg_iterator

[mtrofin]

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

7082

Should we also get 'i' and 'e' to be style-compliant?

llvm/lib/Target/NVPTX/NVPTXISelLowering.h

494

(Here and elsewhere) can CB ever be nullptr? if not, should it be const CallBase &CB (to capture the contract)

[craig.topper]

Use CallBase& in one of the NVPTX function.
Capitalize i/e used as iterators.

[craig.topper]

llvm/lib/Target/PowerPC/PPCISelLowering.h

1173

These methods should maybe be refactored to use the CallLoweringInfo coming into LowerCall instead of passing a bunch of fields from it separately. I might look at that as a follow up.

[craig.topper]

Update one PowerPC function to take a reference. I didn't touch any that should probably take CallLoweringInfo. Since if we made that change they would also use the field which is a pointer.

[mtrofin]

lgtm

llvm/include/llvm/CodeGen/TargetLowering.h

struct CallLoweringInfo {
     bool IsPostTypeLegalization = false;
 
     unsigned NumFixedArgs = -1;
     CallingConv::ID CallConv = CallingConv::C;
     SDValue Callee;
     ArgListTy Args;
     SelectionDAG &DAG;
     SDLoc DL;
-    ImmutableCallSite CS;
+    const CallBase *CB = nullptr;
     SmallVector<ISD::OutputArg, 32> Outs;
     SmallVector<SDValue, 32> OutVals;
     SmallVector<ISD::InputArg, 32> Ins;
     SmallVector<SDValue, 4> InVals;
 
     CallLoweringInfo(SelectionDAG &DAG)
         : RetSExt(false), RetZExt(false), IsVarArg(false), IsInReg(false),
           DoesNotReturn(false), IsReturnValueUsed(true), IsConvergent(false),
CallLoweringInfo &setCallee(CallingConv::ID CC, Type *ResultType,
       CallConv = CC;
       NumFixedArgs = ArgsList.size();
       Args = std::move(ArgsList);
       return *this;
     }
 
     CallLoweringInfo &setCallee(Type *ResultType, FunctionType *FTy,
                                 SDValue Target, ArgListTy &&ArgsList,
-                                ImmutableCallSite Call) {
+                                const CallBase &Call) {
       RetTy = ResultType;
 
       IsInReg = Call.hasRetAttr(Attribute::InReg);
       DoesNotReturn =
           Call.doesNotReturn() ||
-          (!Call.isInvoke() &&
-           isa<UnreachableInst>(Call.getInstruction()->getNextNode()));
+          (!isa<InvokeInst>(Call) && isa<UnreachableInst>(Call.getNextNode()));
       IsVarArg = FTy->isVarArg();
-      IsReturnValueUsed = !Call.getInstruction()->use_empty();
+      IsReturnValueUsed = !Call.use_empty();
       RetSExt = Call.hasRetAttr(Attribute::SExt);
       RetZExt = Call.hasRetAttr(Attribute::ZExt);
 
       Callee = Target;
 
       CallConv = Call.getCallingConv();
       NumFixedArgs = FTy->getNumParams();
       Args = std::move(ArgsList);
 
-      CS = Call;
+      CB = &Call;
 
       return *this;
     }
 
     CallLoweringInfo &setInRegister(bool Value = true) {
       IsInReg = Value;
       return *this;
     }

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h

void EmitBranchForMergedCondition(const Value *Cond, MachineBasicBlock *TBB,
                                     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(ImmutableCallSite CS, SDValue Callee, bool IsTailCall,
+  void LowerCallTo(const CallBase &CB, SDValue Callee, bool IsTailCall,
                    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,

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

else if (Fn && Fn->isIntrinsic()) {
     }
   } else if (I.countOperandBundlesOfType(LLVMContext::OB_deopt)) {
     // Currently we do not lower any intrinsic calls with deopt operand bundles.
     // Eventually we will support lowering the @llvm.experimental.deoptimize
     // intrinsic, and right now there are no plans to support other intrinsics
     // with deopt state.
     LowerCallSiteWithDeoptBundle(&I, getValue(Callee), EHPadBB);
   } else {
-    LowerCallTo(&I, getValue(Callee), false, EHPadBB);
+    LowerCallTo(I, getValue(Callee), false, EHPadBB);
   }
 
   // If the value of the invoke is used outside of its defining block, make it
   // available as a virtual register.
   // We already took care of the exported value for the statepoint instruction
   // during call to the LowerStatepoint.
   if (!isStatepoint(I)) {
     CopyToExportRegsIfNeeded(&I);

 }
 
 void SelectionDAGBuilder::lowerCallToExternalSymbol(const CallInst &I,
                                            const char *FunctionName) {
   assert(FunctionName && "FunctionName must not be nullptr");
   SDValue Callee = DAG.getExternalSymbol(
       FunctionName,
       DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout()));
-  LowerCallTo(&I, Callee, I.isTailCall());
+  LowerCallTo(I, Callee, I.isTailCall());
 }
 
 /// Lower the call to the specified intrinsic function.
 void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
                                              unsigned Intrinsic) {
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   SDLoc sdl = getCurSDLoc();
   DebugLoc dl = getCurDebugLoc();
if (EHPadBB) {
     MCSymbol *EndLabel = MMI.getContext().createTempSymbol();
     DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getRoot(), EndLabel));
 
     // Inform MachineModuleInfo of range.
     auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn());
     // There is a platform (e.g. wasm) that uses funclet style IR but does not
     // actually use outlined funclets and their LSDA info style.
     if (MF.hasEHFunclets() && isFuncletEHPersonality(Pers)) {
-      assert(CLI.CS);
+      assert(CLI.CB);
       WinEHFuncInfo *EHInfo = DAG.getMachineFunction().getWinEHFuncInfo();
-      EHInfo->addIPToStateRange(cast<InvokeInst>(CLI.CS.getInstruction()),
-                                BeginLabel, EndLabel);
+      EHInfo->addIPToStateRange(cast<InvokeInst>(CLI.CB), BeginLabel, EndLabel);
     } else if (!isScopedEHPersonality(Pers)) {
       MF.addInvoke(FuncInfo.MBBMap[EHPadBB], BeginLabel, EndLabel);
     }
   }
 
   return Result;
 }
 
-void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee,
+void SelectionDAGBuilder::LowerCallTo(const CallBase &CB, SDValue Callee,
                                       bool isTailCall,
                                       const BasicBlock *EHPadBB) {
   auto &DL = DAG.getDataLayout();
-  FunctionType *FTy = CS.getFunctionType();
-  Type *RetTy = CS.getType();
+  FunctionType *FTy = CB.getFunctionType();
+  Type *RetTy = CB.getType();
 
   TargetLowering::ArgListTy Args;
-  Args.reserve(CS.arg_size());
+  Args.reserve(CB.arg_size());
 
   const Value *SwiftErrorVal = nullptr;
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
 
   if (isTailCall) {
     // Avoid emitting tail calls in functions with the disable-tail-calls
     // attribute.
-    auto *Caller = CS.getInstruction()->getParent()->getParent();
+    auto *Caller = CB.getParent()->getParent();
     if (Caller->getFnAttribute("disable-tail-calls").getValueAsString() ==
         "true")
       isTailCall = false;
 
     // We can't tail call inside a function with a swifterror argument. Lowering
     // does not support this yet. It would have to move into the swifterror
     // register before the call.
     if (TLI.supportSwiftError() &&
         Caller->getAttributes().hasAttrSomewhere(Attribute::SwiftError))
       isTailCall = false;
   }
 
-  for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
-       i != e; ++i) {
+  for (auto I = CB.arg_begin(), E = CB.arg_end(); I != E; ++I) {
     TargetLowering::ArgListEntry Entry;
-    const Value *V = *i;
+    const Value *V = *I;
 
     // Skip empty types
     if (V->getType()->isEmptyTy())
       continue;
 
     SDValue ArgNode = getValue(V);
     Entry.Node = ArgNode; Entry.Ty = V->getType();
 
-    Entry.setAttributes(&CS, i - CS.arg_begin());
+    Entry.setAttributes(&CB, I - CB.arg_begin());
 
     // Use swifterror virtual register as input to the call.
     if (Entry.IsSwiftError && TLI.supportSwiftError()) {
       SwiftErrorVal = V;
       // We find the virtual register for the actual swifterror argument.
       // Instead of using the Value, we use the virtual register instead.
-      Entry.Node = DAG.getRegister(
-          SwiftError.getOrCreateVRegUseAt(CS.getInstruction(), FuncInfo.MBB, V),
+      Entry.Node =
+          DAG.getRegister(SwiftError.getOrCreateVRegUseAt(&CB, FuncInfo.MBB, V),
                           EVT(TLI.getPointerTy(DL)));
     }
 
     Args.push_back(Entry);
 
     // If we have an explicit sret argument that is an Instruction, (i.e., it
     // might point to function-local memory), we can't meaningfully tail-call.
     if (Entry.IsSRet && isa<Instruction>(V))
       isTailCall = false;
   }
 
   // If call site has a cfguardtarget operand bundle, create and add an
   // additional ArgListEntry.
-  if (auto Bundle = CS.getOperandBundle(LLVMContext::OB_cfguardtarget)) {
+  if (auto Bundle = CB.getOperandBundle(LLVMContext::OB_cfguardtarget)) {
     TargetLowering::ArgListEntry Entry;
     Value *V = Bundle->Inputs[0];
     SDValue ArgNode = getValue(V);
     Entry.Node = ArgNode;
     Entry.Ty = V->getType();
     Entry.IsCFGuardTarget = true;
     Args.push_back(Entry);
   }
 
   // Check if target-independent constraints permit a tail call here.
   // Target-dependent constraints are checked within TLI->LowerCallTo.
-  if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget()))
+  if (isTailCall &&
+      !isInTailCallPosition(ImmutableCallSite(&CB), DAG.getTarget()))
     isTailCall = false;
 
   // Disable tail calls if there is an swifterror argument. Targets have not
   // been updated to support tail calls.
   if (TLI.supportSwiftError() && SwiftErrorVal)
     isTailCall = false;
 
   TargetLowering::CallLoweringInfo CLI(DAG);
   CLI.setDebugLoc(getCurSDLoc())
       .setChain(getRoot())
-      .setCallee(RetTy, FTy, Callee, std::move(Args), CS)
+      .setCallee(RetTy, FTy, Callee, std::move(Args), CB)
       .setTailCall(isTailCall)
-      .setConvergent(CS.isConvergent());
+      .setConvergent(CB.isConvergent());
   std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB);
 
   if (Result.first.getNode()) {
-    const Instruction *Inst = CS.getInstruction();
-    Result.first = lowerRangeToAssertZExt(DAG, *Inst, Result.first);
-    setValue(Inst, Result.first);
+    Result.first = lowerRangeToAssertZExt(DAG, CB, Result.first);
+    setValue(&CB, Result.first);
   }
 
   // The last element of CLI.InVals has the SDValue for swifterror return.
   // Here we copy it to a virtual register and update SwiftErrorMap for
   // book-keeping.
   if (SwiftErrorVal && TLI.supportSwiftError()) {
     // Get the last element of InVals.
     SDValue Src = CLI.InVals.back();
-    Register VReg = SwiftError.getOrCreateVRegDefAt(
-        CS.getInstruction(), FuncInfo.MBB, SwiftErrorVal);
+    Register VReg =
+        SwiftError.getOrCreateVRegDefAt(&CB, FuncInfo.MBB, SwiftErrorVal);
     SDValue CopyNode = CLI.DAG.getCopyToReg(Result.second, CLI.DL, VReg, Src);
     DAG.setRoot(CopyNode);
   }
 }
 
 static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT,
                              SelectionDAGBuilder &Builder) {
   // Check to see if this load can be trivially constant folded, e.g. if the
void SelectionDAGBuilder::visitCall(const CallInst &I) {
   SDValue Callee = getValue(I.getCalledValue());
 
   if (I.countOperandBundlesOfType(LLVMContext::OB_deopt))
     LowerCallSiteWithDeoptBundle(&I, Callee, nullptr);
   else
     // Check if we can potentially perform a tail call. More detailed checking
     // is be done within LowerCallTo, after more information about the call is
     // known.
-    LowerCallTo(&I, Callee, I.isTailCall());
+    LowerCallTo(I, Callee, I.isTailCall());
 }
 
 namespace {
 
 /// AsmOperandInfo - This contains information for each constraint that we are
 /// lowering.
 class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo {
 public:
for (unsigned Value = 0, NumValues = ValueVTs.size(); Value != NumValues;
         // parameter extension method is not compatible with the return
         // extension method
         if ((NumParts * PartVT.getSizeInBits() == VT.getSizeInBits()) ||
             (ExtendKind != ISD::ANY_EXTEND && CLI.RetSExt == Args[i].IsSExt &&
              CLI.RetZExt == Args[i].IsZExt))
           Flags.setReturned();
       }
 
-      getCopyToParts(CLI.DAG, CLI.DL, Op, &Parts[0], NumParts, PartVT,
-                     CLI.CS.getInstruction(), CLI.CallConv, ExtendKind);
+      getCopyToParts(CLI.DAG, CLI.DL, Op, &Parts[0], NumParts, PartVT, CLI.CB,
+                     CLI.CallConv, ExtendKind);
 
       for (unsigned j = 0; j != NumParts; ++j) {
         // if it isn't first piece, alignment must be 1
         // For scalable vectors the scalable part is currently handled
         // by individual targets, so we just use the known minimum size here.
         ISD::OutputArg MyFlags(Flags, Parts[j].getValueType(), VT,
                     i < CLI.NumFixedArgs, i,
                     j*Parts[j].getValueType().getStoreSize().getKnownMinSize());

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
   AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
   bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
   bool IsSibCall = false;
 
   if (IsTailCall) {
     // Check if it's really possible to do a tail call.
     IsTailCall = isEligibleForTailCallOptimization(
         Callee, CallConv, IsVarArg, Outs, OutVals, Ins, DAG);
-    if (!IsTailCall && CLI.CS && CLI.CS.isMustTailCall())
+    if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
       report_fatal_error("failed to perform tail call elimination on a call "
                          "site marked musttail");
 
     // A sibling call is one where we're under the usual C ABI and not planning
     // to change that but can still do a tail call:
     if (!TailCallOpt && IsTailCall)
       IsSibCall = true;
 
AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
   SDValue StackPtr = DAG.getCopyFromReg(Chain, DL, AArch64::SP,
                                         getPointerTy(DAG.getDataLayout()));
 
   SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
   SmallSet<unsigned, 8> RegsUsed;
   SmallVector<SDValue, 8> MemOpChains;
   auto PtrVT = getPointerTy(DAG.getDataLayout());
 
-  if (IsVarArg && CLI.CS && CLI.CS.isMustTailCall()) {
+  if (IsVarArg && CLI.CB && CLI.CB->isMustTailCall()) {
     const auto &Forwards = FuncInfo->getForwardedMustTailRegParms();
     for (const auto &F : Forwards) {
       SDValue Val = DAG.getCopyFromReg(Chain, DL, F.VReg, F.VT);
        RegsToPass.emplace_back(F.PReg, Val);
     }
   }
 
   // Walk the register/memloc assignments, inserting copies/loads.

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

void SITargetLowering::passSpecialInputs(
     CallLoweringInfo &CLI,
     CCState &CCInfo,
     const SIMachineFunctionInfo &Info,
     SmallVectorImpl<std::pair<unsigned, SDValue>> &RegsToPass,
     SmallVectorImpl<SDValue> &MemOpChains,
     SDValue Chain) const {
   // If we don't have a call site, this was a call inserted by
   // legalization. These can never use special inputs.
-  if (!CLI.CS)
+  if (!CLI.CB)
     return;
 
   SelectionDAG &DAG = CLI.DAG;
   const SDLoc &DL = CLI.DL;
 
   const SIRegisterInfo *TRI = Subtarget->getRegisterInfo();
   const AMDGPUFunctionArgInfo &CallerArgInfo = Info.getArgInfo();
 
   const AMDGPUFunctionArgInfo *CalleeArgInfo
     = &AMDGPUArgumentUsageInfo::FixedABIFunctionInfo;
-  if (const Function *CalleeFunc = CLI.CS.getCalledFunction()) {
+  if (const Function *CalleeFunc = CLI.CB->getCalledFunction()) {
     auto &ArgUsageInfo =
       DAG.getPass()->getAnalysis<AMDGPUArgumentUsageInfo>();
     CalleeArgInfo = &ArgUsageInfo.lookupFuncArgInfo(*CalleeFunc);
   }
 
   // TODO: Unify with private memory register handling. This is complicated by
   // the fact that at least in kernels, the input argument is not necessarily
   // in the same location as the input.
if (Callee.isUndef() || isNullConstant(Callee)) {
     return Chain;
   }
 
   if (IsVarArg) {
     return lowerUnhandledCall(CLI, InVals,
                               "unsupported call to variadic function ");
   }
 
-  if (!CLI.CS.getInstruction())
+  if (!CLI.CB)
     report_fatal_error("unsupported libcall legalization");
 
-  if (!AMDGPUTargetMachine::EnableFixedFunctionABI && !CLI.CS.getCalledFunction()) {
+  if (!AMDGPUTargetMachine::EnableFixedFunctionABI &&
+      !CLI.CB->getCalledFunction()) {
     return lowerUnhandledCall(CLI, InVals,
                               "unsupported indirect call to function ");
   }
 
   if (IsTailCall && MF.getTarget().Options.GuaranteedTailCallOpt) {
     return lowerUnhandledCall(CLI, InVals,
                               "unsupported required tail call to function ");
   }
 
   if (AMDGPU::isShader(MF.getFunction().getCallingConv())) {
     // Note the issue is with the CC of the calling function, not of the call
     // itself.
     return lowerUnhandledCall(CLI, InVals,
                           "unsupported call from graphics shader of function ");
   }
 
   if (IsTailCall) {
     IsTailCall = isEligibleForTailCallOptimization(
       Callee, CallConv, IsVarArg, Outs, OutVals, Ins, DAG);
-    if (!IsTailCall && CLI.CS && CLI.CS.isMustTailCall()) {
+    if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall()) {
       report_fatal_error("failed to perform tail call elimination on a call "
                          "site marked musttail");
     }
 
     bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
 
     // A sibling call is one where we're under the usual C ABI and not planning
     // to change that but can still do a tail call:

llvm/lib/Target/ARM/ARMISelLowering.cpp

ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   if (!Subtarget->supportsTailCall())
     isTailCall = false;
 
   if (isa<GlobalAddressSDNode>(Callee)) {
     // If we're optimizing for minimum size and the function is called three or
     // more times in this block, we can improve codesize by calling indirectly
     // as BLXr has a 16-bit encoding.
     auto *GV = cast<GlobalAddressSDNode>(Callee)->getGlobal();
-    if (CLI.CS) {
-      auto *BB = CLI.CS.getParent();
+    if (CLI.CB) {
+      auto *BB = CLI.CB->getParent();
       PreferIndirect = Subtarget->isThumb() && Subtarget->hasMinSize() &&
                        count_if(GV->users(), [&BB](const User *U) {
                          return isa<Instruction>(U) &&
                                 cast<Instruction>(U)->getParent() == BB;
                        }) > 2;
     }
   }
   if (isTailCall) {
     // Check if it's really possible to do a tail call.
     isTailCall = IsEligibleForTailCallOptimization(
         Callee, CallConv, isVarArg, isStructRet,
         MF.getFunction().hasStructRetAttr(), Outs, OutVals, Ins, DAG,
         PreferIndirect);
-    if (!isTailCall && CLI.CS && CLI.CS.isMustTailCall())
+    if (!isTailCall && CLI.CB && CLI.CB->isMustTailCall())
       report_fatal_error("failed to perform tail call elimination on a call "
                          "site marked musttail");
     // We don't support GuaranteedTailCallOpt for ARM, only automatically
     // detected sibcalls.
     if (isTailCall)
       ++NumTailCalls;
   }
 

llvm/lib/Target/Hexagon/HexagonISelLowering.cpp

HexagonTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   bool IsVarArg                         = CLI.IsVarArg;
   bool DoesNotReturn                    = CLI.DoesNotReturn;
 
   bool IsStructRet    = Outs.empty() ? false : Outs[0].Flags.isSRet();
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo &MFI = MF.getFrameInfo();
   auto PtrVT = getPointerTy(MF.getDataLayout());
 
-  unsigned NumParams = CLI.CS.getInstruction()
-                        ? CLI.CS.getFunctionType()->getNumParams()
-                        : 0;
+  unsigned NumParams = CLI.CB ? CLI.CB->getFunctionType()->getNumParams() : 0;
   if (GlobalAddressSDNode *GAN = dyn_cast<GlobalAddressSDNode>(Callee))
     Callee = DAG.getTargetGlobalAddress(GAN->getGlobal(), dl, MVT::i32);
 
   // Linux ABI treats var-arg calls the same way as regular ones.
   bool TreatAsVarArg = !Subtarget.isEnvironmentMusl() && IsVarArg;
 
   // Analyze operands of the call, assigning locations to each operand.
   SmallVector<CCValAssign, 16> ArgLocs;

llvm/lib/Target/Mips/MipsISelLowering.cpp

if (IsTailCall) {
      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
       InternalLinkage = G->getGlobal()->hasInternalLinkage();
       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
                      G->getGlobal()->hasPrivateLinkage() ||
                      G->getGlobal()->hasHiddenVisibility() ||
                      G->getGlobal()->hasProtectedVisibility());
      }
   }
-  if (!IsTailCall && CLI.CS && CLI.CS.isMustTailCall())
+  if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
     report_fatal_error("failed to perform tail call elimination on a call "
                        "site marked musttail");
 
   if (IsTailCall)
     ++NumTailCalls;
 
   // Chain is the output chain of the last Load/Store or CopyToReg node.
   // ByValChain is the output chain of the last Memcpy node created for copying

llvm/lib/Target/NVPTX/NVPTXISelLowering.h

SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
                                const SDLoc &dl, SelectionDAG &DAG,
                                SmallVectorImpl<SDValue> &InVals) const override;
 
   SDValue LowerCall(CallLoweringInfo &CLI,
                     SmallVectorImpl<SDValue> &InVals) const override;
 
   std::string getPrototype(const DataLayout &DL, Type *, const ArgListTy &,
                            const SmallVectorImpl<ISD::OutputArg> &,
-                           MaybeAlign retAlignment, ImmutableCallSite CS) const;
+                           MaybeAlign retAlignment, const CallBase &CB) const;
 
   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
                       const SmallVectorImpl<ISD::OutputArg> &Outs,
                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &dl,
                       SelectionDAG &DAG) const override;
 
   void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
                                     std::vector<SDValue> &Ops,
private:
   SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
 
   SDValue LowerSelect(SDValue Op, SelectionDAG &DAG) const;
 
   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
                           SelectionDAG &DAG) const override;
   SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
 
-  Align getArgumentAlignment(SDValue Callee, ImmutableCallSite CS, Type *Ty,
+  Align getArgumentAlignment(SDValue Callee, const CallBase *CB, Type *Ty,
                              unsigned Idx, const DataLayout &DL) const;
 };
 } // namespace llvm
 
 #endif

llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp

NVPTXTargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
   auto PtrVT = getPointerTy(DAG.getDataLayout(), GAN->getAddressSpace());
   Op = DAG.getTargetGlobalAddress(GAN->getGlobal(), dl, PtrVT);
   return DAG.getNode(NVPTXISD::Wrapper, dl, PtrVT, Op);
 }
 
 std::string NVPTXTargetLowering::getPrototype(
     const DataLayout &DL, Type *retTy, const ArgListTy &Args,
     const SmallVectorImpl<ISD::OutputArg> &Outs, MaybeAlign retAlignment,
-    ImmutableCallSite CS) const {
+    const CallBase &CB) const {
   auto PtrVT = getPointerTy(DL);
 
   bool isABI = (STI.getSmVersion() >= 20);
   assert(isABI && "Non-ABI compilation is not supported");
   if (!isABI)
     return "";
 
   std::stringstream O;
for (unsigned i = 0, e = Args.size(); i != e; ++i, ++OIdx) {
     if (!first) {
       O << ", ";
     }
     first = false;
 
     if (!Outs[OIdx].Flags.isByVal()) {
       if (Ty->isAggregateType() || Ty->isVectorTy() || Ty->isIntegerTy(128)) {
         unsigned align = 0;
-        const CallInst *CallI = cast<CallInst>(CS.getInstruction());
+        const CallInst *CallI = cast<CallInst>(&CB);
         // +1 because index 0 is reserved for return type alignment
         if (!getAlign(*CallI, i + 1, align))
           align = DL.getABITypeAlignment(Ty);
         unsigned sz = DL.getTypeAllocSize(Ty);
         O << ".param .align " << align << " .b8 ";
         O << "_";
         O << "[" << sz << "]";
         // update the index for Outs
for (unsigned i = 0, e = Args.size(); i != e; ++i, ++OIdx) {
     O << "_";
     O << "[" << sz << "]";
   }
   O << ");";
   return O.str();
 }
 
 Align NVPTXTargetLowering::getArgumentAlignment(SDValue Callee,
-                                                ImmutableCallSite CS, Type *Ty,
+                                                const CallBase *CB, Type *Ty,
                                                 unsigned Idx,
                                                 const DataLayout &DL) const {
-  if (!CS) {
+  if (!CB) {
     // CallSite is zero, fallback to ABI type alignment
     return DL.getABITypeAlign(Ty);
   }
 
   unsigned Alignment = 0;
-  const Value *DirectCallee = CS.getCalledFunction();
+  const Value *DirectCallee = CB->getCalledFunction();
 
   if (!DirectCallee) {
     // We don't have a direct function symbol, but that may be because of
     // constant cast instructions in the call.
-    const Instruction *CalleeI = CS.getInstruction();
-    assert(CalleeI && "Call target is not a function or derived value?");
 
     // With bitcast'd call targets, the instruction will be the call
-    if (isa<CallInst>(CalleeI)) {
+    if (isa<CallInst>(CB)) {
       // Check if we have call alignment metadata
-      if (getAlign(*cast<CallInst>(CalleeI), Idx, Alignment))
+      if (getAlign(*cast<CallInst>(CB), Idx, Alignment))
         return Align(Alignment);
 
-      const Value *CalleeV = cast<CallInst>(CalleeI)->getCalledValue();
+      const Value *CalleeV = cast<CallInst>(CB)->getCalledValue();
       // Ignore any bitcast instructions
       while (isa<ConstantExpr>(CalleeV)) {
         const ConstantExpr *CE = cast<ConstantExpr>(CalleeV);
         if (!CE->isCast())
           break;
         // Look through the bitcast
         CalleeV = cast<ConstantExpr>(CalleeV)->getOperand(0);
       }
SDValue NVPTXTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
   SmallVectorImpl<SDValue> &OutVals = CLI.OutVals;
   SmallVectorImpl<ISD::InputArg> &Ins = CLI.Ins;
   SDValue Chain = CLI.Chain;
   SDValue Callee = CLI.Callee;
   bool &isTailCall = CLI.IsTailCall;
   ArgListTy &Args = CLI.getArgs();
   Type *RetTy = CLI.RetTy;
-  ImmutableCallSite CS = CLI.CS;
+  const CallBase *CB = CLI.CB;
   const DataLayout &DL = DAG.getDataLayout();
 
   bool isABI = (STI.getSmVersion() >= 20);
   assert(isABI && "Non-ABI compilation is not supported");
   if (!isABI)
     return Chain;
 
   SDValue tempChain = Chain;
SDValue NVPTXTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   for (unsigned i = 0, e = Args.size(); i != e; ++i, ++OIdx) {
     EVT VT = Outs[OIdx].VT;
     Type *Ty = Args[i].Ty;
 
     if (!Outs[OIdx].Flags.isByVal()) {
       SmallVector<EVT, 16> VTs;
       SmallVector<uint64_t, 16> Offsets;
       ComputePTXValueVTs(*this, DL, Ty, VTs, &Offsets);
-      Align ArgAlign = getArgumentAlignment(Callee, CS, Ty, paramCount + 1, DL);
+      Align ArgAlign = getArgumentAlignment(Callee, CB, Ty, paramCount + 1, DL);
       unsigned AllocSize = DL.getTypeAllocSize(Ty);
       SDVTList DeclareParamVTs = DAG.getVTList(MVT::Other, MVT::Glue);
       bool NeedAlign; // Does argument declaration specify alignment?
       if (Ty->isAggregateType() || Ty->isVectorTy() || Ty->isIntegerTy(128)) {
         // declare .param .align <align> .b8 .param<n>[<size>];
         SDValue DeclareParamOps[] = {
             Chain, DAG.getConstant(ArgAlign.value(), dl, MVT::i32),
             DAG.getConstant(paramCount, dl, MVT::i32),
if (RetTy->isFloatingPointTy() || RetTy->isPointerTy() ||
       SDVTList DeclareRetVTs = DAG.getVTList(MVT::Other, MVT::Glue);
       SDValue DeclareRetOps[] = { Chain, DAG.getConstant(1, dl, MVT::i32),
                                   DAG.getConstant(resultsz, dl, MVT::i32),
                                   DAG.getConstant(0, dl, MVT::i32), InFlag };
       Chain = DAG.getNode(NVPTXISD::DeclareRet, dl, DeclareRetVTs,
                           DeclareRetOps);
       InFlag = Chain.getValue(1);
     } else {
-      retAlignment = getArgumentAlignment(Callee, CS, RetTy, 0, DL);
+      retAlignment = getArgumentAlignment(Callee, CB, RetTy, 0, DL);
       assert(retAlignment && "retAlignment is guaranteed to be set");
       SDVTList DeclareRetVTs = DAG.getVTList(MVT::Other, MVT::Glue);
       SDValue DeclareRetOps[] = {
           Chain, DAG.getConstant(retAlignment->value(), dl, MVT::i32),
           DAG.getConstant(resultsz / 8, dl, MVT::i32),
           DAG.getConstant(0, dl, MVT::i32), InFlag};
       Chain = DAG.getNode(NVPTXISD::DeclareRetParam, dl, DeclareRetVTs,
                           DeclareRetOps);
       InFlag = Chain.getValue(1);
     }
   }
 
   // Both indirect calls and libcalls have nullptr Func. In order to distinguish
   // between them we must rely on the call site value which is valid for
   // indirect calls but is always null for libcalls.
-  bool isIndirectCall = !Func && CS;
+  bool isIndirectCall = !Func && CB;
 
   if (isa<ExternalSymbolSDNode>(Callee)) {
     Function* CalleeFunc = nullptr;
 
     // Try to find the callee in the current module.
     Callee = DAG.getSymbolFunctionGlobalAddress(Callee, &CalleeFunc);
     assert(CalleeFunc != nullptr && "Libcall callee must be set.");
 
     // Set the "libcall callee" attribute to indicate that the function
     // must always have a declaration.
     CalleeFunc->addFnAttr("nvptx-libcall-callee", "true");
   }
 
   if (isIndirectCall) {
     // This is indirect function call case : PTX requires a prototype of the
     // form
     // proto_0 : .callprototype(.param .b32 _) _ (.param .b32 _);
     // to be emitted, and the label has to used as the last arg of call
     // instruction.
     // The prototype is embedded in a string and put as the operand for a
     // CallPrototype SDNode which will print out to the value of the string.
     SDVTList ProtoVTs = DAG.getVTList(MVT::Other, MVT::Glue);
-    std::string Proto = getPrototype(DL, RetTy, Args, Outs, retAlignment, CS);
+    std::string Proto = getPrototype(DL, RetTy, Args, Outs, retAlignment, *CB);
     const char *ProtoStr =
       nvTM->getManagedStrPool()->getManagedString(Proto.c_str())->c_str();
     SDValue ProtoOps[] = {
       Chain, DAG.getTargetExternalSymbol(ProtoStr, MVT::i32), InFlag,
     };
     Chain = DAG.getNode(NVPTXISD::CallPrototype, dl, ProtoVTs, ProtoOps);
     InFlag = Chain.getValue(1);
   }
SDValue NVPTXTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
 
   // Generate loads from param memory/moves from registers for result
   if (Ins.size() > 0) {
     SmallVector<EVT, 16> VTs;
     SmallVector<uint64_t, 16> Offsets;
     ComputePTXValueVTs(*this, DL, RetTy, VTs, &Offsets, 0);
     assert(VTs.size() == Ins.size() && "Bad value decomposition");
 
-    Align RetAlign = getArgumentAlignment(Callee, CS, RetTy, 0, DL);
+    Align RetAlign = getArgumentAlignment(Callee, CB, RetTy, 0, DL);
     auto VectorInfo = VectorizePTXValueVTs(VTs, Offsets, RetAlign);
 
     SmallVector<EVT, 6> LoadVTs;
     int VecIdx = -1; // Index of the first element of the vector.
 
     // PTX Interoperability Guide 3.3(A): [Integer] Values shorter than
     // 32-bits are sign extended or zero extended, depending on whether
     // they are signed or unsigned types.

llvm/lib/Target/PowerPC/PPCISelLowering.h

private:
 
     bool
     IsEligibleForTailCallOptimization(SDValue Callee,
                                       CallingConv::ID CalleeCC,
                                       bool isVarArg,
                                       const SmallVectorImpl<ISD::InputArg> &Ins,
                                       SelectionDAG& DAG) const;
 
-    bool
-    IsEligibleForTailCallOptimization_64SVR4(
-                                    SDValue Callee,
-                                    CallingConv::ID CalleeCC,
-                                    ImmutableCallSite CS,
-                                    bool isVarArg,
-                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
-                                    const SmallVectorImpl<ISD::InputArg> &Ins,
-                                    SelectionDAG& DAG) const;
+    bool IsEligibleForTailCallOptimization_64SVR4(
+        SDValue Callee, CallingConv::ID CalleeCC, const CallBase *CB,
+        bool isVarArg, const SmallVectorImpl<ISD::OutputArg> &Outs,
+        const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG &DAG) const;
 
     SDValue EmitTailCallLoadFPAndRetAddr(SelectionDAG &DAG, int SPDiff,
                                          SDValue Chain, SDValue &LROpOut,
                                          SDValue &FPOpOut,
                                          const SDLoc &dl) const;
 
     SDValue getTOCEntry(SelectionDAG &DAG, const SDLoc &dl, SDValue GA) const;
 
SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
                             SmallVectorImpl<SDValue> &InVals) const;
 
     SDValue FinishCall(CallFlags CFlags, const SDLoc &dl, SelectionDAG &DAG,
                        SmallVector<std::pair<unsigned, SDValue>, 8> &RegsToPass,
                        SDValue InFlag, SDValue Chain, SDValue CallSeqStart,
                        SDValue &Callee, int SPDiff, unsigned NumBytes,
                        const SmallVectorImpl<ISD::InputArg> &Ins,
                        SmallVectorImpl<SDValue> &InVals,
-                       ImmutableCallSite CS) const;
+                       const CallBase *CB) const;
 
     SDValue
     LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
                          const SmallVectorImpl<ISD::InputArg> &Ins,
                          const SDLoc &dl, SelectionDAG &DAG,
                          SmallVectorImpl<SDValue> &InVals) const override;
 
     SDValue LowerCall(TargetLowering::CallLoweringInfo &CLI,
SDValue LowerFormalArguments_32SVR4(
         const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
         SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const;
 
     SDValue createMemcpyOutsideCallSeq(SDValue Arg, SDValue PtrOff,
                                        SDValue CallSeqStart,
                                        ISD::ArgFlagsTy Flags, SelectionDAG &DAG,
                                        const SDLoc &dl) const;
 
     SDValue LowerCall_Darwin(SDValue Chain, SDValue Callee, CallFlags CFlags,
                              const SmallVectorImpl<ISD::OutputArg> &Outs,
                              const SmallVectorImpl<SDValue> &OutVals,
                              const SmallVectorImpl<ISD::InputArg> &Ins,
                              const SDLoc &dl, SelectionDAG &DAG,
                              SmallVectorImpl<SDValue> &InVals,
-                             ImmutableCallSite CS) const;
+                             const CallBase *CB) const;
     SDValue LowerCall_64SVR4(SDValue Chain, SDValue Callee, CallFlags CFlags,
                              const SmallVectorImpl<ISD::OutputArg> &Outs,
                              const SmallVectorImpl<SDValue> &OutVals,
                              const SmallVectorImpl<ISD::InputArg> &Ins,
                              const SDLoc &dl, SelectionDAG &DAG,
                              SmallVectorImpl<SDValue> &InVals,
-                             ImmutableCallSite CS) const;
+                             const CallBase *CB) const;
     SDValue LowerCall_32SVR4(SDValue Chain, SDValue Callee, CallFlags CFlags,
                              const SmallVectorImpl<ISD::OutputArg> &Outs,
                              const SmallVectorImpl<SDValue> &OutVals,
                              const SmallVectorImpl<ISD::InputArg> &Ins,
                              const SDLoc &dl, SelectionDAG &DAG,
                              SmallVectorImpl<SDValue> &InVals,
-                             ImmutableCallSite CS) const;
+                             const CallBase *CB) const;
     SDValue LowerCall_AIX(SDValue Chain, SDValue Callee, CallFlags CFlags,
                           const SmallVectorImpl<ISD::OutputArg> &Outs,
                           const SmallVectorImpl<SDValue> &OutVals,
                           const SmallVectorImpl<ISD::InputArg> &Ins,
                           const SDLoc &dl, SelectionDAG &DAG,
                           SmallVectorImpl<SDValue> &InVals,
-                          ImmutableCallSite CS) const;
+                          const CallBase *CB) const;
 
     SDValue lowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
     SDValue lowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerBITCAST(SDValue Op, SelectionDAG &DAG) const;
 
     SDValue DAGCombineExtBoolTrunc(SDNode *N, DAGCombinerInfo &DCI) const;
     SDValue DAGCombineBuildVector(SDNode *N, DAGCombinerInfo &DCI) const;
     SDValue DAGCombineTruncBoolExt(SDNode *N, DAGCombinerInfo &DCI) const;

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

if (CalculateStackSlotUsed(Param.VT, Param.ArgVT, Param.Flags,
                                PtrByteSize, LinkageSize, ParamAreaSize,
                                NumBytes, AvailableFPRs, AvailableVRs,
                                Subtarget.hasQPX()))
       return true;
   }
   return false;
 }
 
-static bool
-hasSameArgumentList(const Function *CallerFn, ImmutableCallSite CS) {
-  if (CS.arg_size() != CallerFn->arg_size())
+static bool hasSameArgumentList(const Function *CallerFn, const CallBase *CB) {
+  if (CB->arg_size() != CallerFn->arg_size())
     return false;
 
-  ImmutableCallSite::arg_iterator CalleeArgIter = CS.arg_begin();
-  ImmutableCallSite::arg_iterator CalleeArgEnd = CS.arg_end();
+  auto CalleeArgIter = CB->arg_begin();
+  auto CalleeArgEnd = CB->arg_end();
   Function::const_arg_iterator CallerArgIter = CallerFn->arg_begin();
 
   for (; CalleeArgIter != CalleeArgEnd; ++CalleeArgIter, ++CallerArgIter) {
     const Value* CalleeArg = *CalleeArgIter;
     const Value* CallerArg = &(*CallerArgIter);
     if (CalleeArg == CallerArg)
       continue;
 
areCallingConvEligibleForTCO_64SVR4(CallingConv::ID CallerCC,
 
   // We can safely tail call both fastcc and ccc callees from a c calling
   // convention caller. If the caller is fastcc, we may have less stack space
   // than a non-fastcc caller with the same signature so disable tail-calls in
   // that case.
   return CallerCC == CallingConv::C || CallerCC == CalleeCC;
 }
 
-bool
-PPCTargetLowering::IsEligibleForTailCallOptimization_64SVR4(
-                                    SDValue Callee,
-                                    CallingConv::ID CalleeCC,
-                                    ImmutableCallSite CS,
-                                    bool isVarArg,
-                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
-                                    const SmallVectorImpl<ISD::InputArg> &Ins,
-                                    SelectionDAG& DAG) const {
+bool PPCTargetLowering::IsEligibleForTailCallOptimization_64SVR4(
+    SDValue Callee, CallingConv::ID CalleeCC, const CallBase *CB, bool isVarArg,
+    const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG &DAG) const {
   bool TailCallOpt = getTargetMachine().Options.GuaranteedTailCallOpt;
 
   // FIXME: Tail calls are currently disabled when using PC Relative addressing.
   // The issue is that PC Relative is only partially implemented and so there
   // is currently a mix of functions that require the TOC and functions that do
   // not require it. If we have A calls B calls C and both A and B require the
   // TOC and C does not and is marked as clobbering R2 then it is not safe for
   // B to tail call C. Since we do not have the information of whether or not
bool PPCTargetLowering::IsEligibleForTailCallOptimization_64SVR4(
   if (CalleeCC == CallingConv::Fast && TailCallOpt)
     return true;
 
   if (DisableSCO) return false;
 
   // If callee use the same argument list that caller is using, then we can
   // apply SCO on this case. If it is not, then we need to check if callee needs
   // stack for passing arguments.
-  if (!hasSameArgumentList(&Caller, CS) &&
+  if (!hasSameArgumentList(&Caller, CB) &&
       needStackSlotPassParameters(Subtarget, Outs)) {
     return false;
   }
 
   return true;
 }
 
 /// IsEligibleForTailCallOptimization - Check whether the call is eligible
Chain = DAG.getNode(PPCISD::MTCTR, dl, makeArrayRef(ReturnTypes, 2),
                       makeArrayRef(MTCTROps, Glue.getNode() ? 3 : 2));
   // The glue is the second value produced.
   Glue = Chain.getValue(1);
 }
 
 static void prepareDescriptorIndirectCall(SelectionDAG &DAG, SDValue &Callee,
                                           SDValue &Glue, SDValue &Chain,
                                           SDValue CallSeqStart,
-                                          ImmutableCallSite CS, const SDLoc &dl,
+                                          const CallBase *CB, const SDLoc &dl,
                                           bool hasNest,
                                           const PPCSubtarget &Subtarget) {
   // Function pointers in the 64-bit SVR4 ABI do not point to the function
   // entry point, but to the function descriptor (the function entry point
   // address is part of the function descriptor though).
   // The function descriptor is a three doubleword structure with the
   // following fields: function entry point, TOC base address and
   // environment pointer.
static void prepareDescriptorIndirectCall(SelectionDAG &DAG, SDValue &Callee,
 
   // Start by loading the function address from the descriptor.
   SDValue LDChain = getOutputChainFromCallSeq(CallSeqStart);
   auto MMOFlags = Subtarget.hasInvariantFunctionDescriptors()
                       ? (MachineMemOperand::MODereferenceable |
                          MachineMemOperand::MOInvariant)
                       : MachineMemOperand::MONone;
 
-  MachinePointerInfo MPI(CS ? CS.getCalledValue() : nullptr);
+  MachinePointerInfo MPI(CB ? CB->getCalledValue() : nullptr);
 
   // Registers used in building the DAG.
   const MCRegister EnvPtrReg = Subtarget.getEnvironmentPointerRegister();
   const MCRegister TOCReg = Subtarget.getTOCPointerRegister();
 
   // Offsets of descriptor members.
   const unsigned TOCAnchorOffset = Subtarget.descriptorTOCAnchorOffset();
   const unsigned EnvPtrOffset = Subtarget.descriptorEnvironmentPointerOffset();
if (Glue.getNode())
     Ops.push_back(Glue);
 }
 
 SDValue PPCTargetLowering::FinishCall(
     CallFlags CFlags, const SDLoc &dl, SelectionDAG &DAG,
     SmallVector<std::pair<unsigned, SDValue>, 8> &RegsToPass, SDValue Glue,
     SDValue Chain, SDValue CallSeqStart, SDValue &Callee, int SPDiff,
     unsigned NumBytes, const SmallVectorImpl<ISD::InputArg> &Ins,
-    SmallVectorImpl<SDValue> &InVals, ImmutableCallSite CS) const {
+    SmallVectorImpl<SDValue> &InVals, const CallBase *CB) const {
 
   if ((Subtarget.is64BitELFABI() && !Subtarget.isUsingPCRelativeCalls()) ||
       Subtarget.isAIXABI())
     setUsesTOCBasePtr(DAG);
 
   unsigned CallOpc =
       getCallOpcode(CFlags, DAG.getMachineFunction().getFunction(), Callee,
                     Subtarget, DAG.getTarget());
 
   if (!CFlags.IsIndirect)
     Callee = transformCallee(Callee, DAG, dl, Subtarget);
   else if (Subtarget.usesFunctionDescriptors())
-    prepareDescriptorIndirectCall(DAG, Callee, Glue, Chain, CallSeqStart, CS,
+    prepareDescriptorIndirectCall(DAG, Callee, Glue, Chain, CallSeqStart, CB,
                                   dl, CFlags.HasNest, Subtarget);
   else
     prepareIndirectCall(DAG, Callee, Glue, Chain, dl);
 
   // Build the operand list for the call instruction.
   SmallVector<SDValue, 8> Ops;
   buildCallOperands(Ops, CFlags, dl, DAG, RegsToPass, Glue, Chain, Callee,
                     SPDiff, Subtarget);
PPCTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
   SDValue Chain                         = CLI.Chain;
   SDValue Callee                        = CLI.Callee;
   bool &isTailCall                      = CLI.IsTailCall;
   CallingConv::ID CallConv              = CLI.CallConv;
   bool isVarArg                         = CLI.IsVarArg;
   bool isPatchPoint                     = CLI.IsPatchPoint;
-  ImmutableCallSite CS                  = CLI.CS;
+  const CallBase *CB                    = CLI.CB;
 
   if (isTailCall) {
-    if (Subtarget.useLongCalls() && !(CS && CS.isMustTailCall()))
+    if (Subtarget.useLongCalls() && !(CB && CB->isMustTailCall()))
       isTailCall = false;
     else if (Subtarget.isSVR4ABI() && Subtarget.isPPC64())
-      isTailCall =
-        IsEligibleForTailCallOptimization_64SVR4(Callee, CallConv, CS,
-                                                 isVarArg, Outs, Ins, DAG);
+      isTailCall = IsEligibleForTailCallOptimization_64SVR4(
+          Callee, CallConv, CB, isVarArg, Outs, Ins, DAG);
     else
       isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv, isVarArg,
                                                      Ins, DAG);
     if (isTailCall) {
       ++NumTailCalls;
       if (!getTargetMachine().Options.GuaranteedTailCallOpt)
         ++NumSiblingCalls;
 
       assert(isa<GlobalAddressSDNode>(Callee) &&
              "Callee should be an llvm::Function object.");
       LLVM_DEBUG(
           const GlobalValue *GV =
               cast<GlobalAddressSDNode>(Callee)->getGlobal();
           const unsigned Width =
               80 - strlen("TCO caller: ") - strlen(", callee linkage: 0, 0");
           dbgs() << "TCO caller: "
                  << left_justify(DAG.getMachineFunction().getName(), Width)
                  << ", callee linkage: " << GV->getVisibility() << ", "
                  << GV->getLinkage() << "\n");
     }
   }
 
-  if (!isTailCall && CS && CS.isMustTailCall())
+  if (!isTailCall && CB && CB->isMustTailCall())
     report_fatal_error("failed to perform tail call elimination on a call "
                        "site marked musttail");
 
   // When long calls (i.e. indirect calls) are always used, calls are always
   // made via function pointer. If we have a function name, first translate it
   // into a pointer.
   if (Subtarget.useLongCalls() && isa<GlobalAddressSDNode>(Callee) &&
       !isTailCall)
     Callee = LowerGlobalAddress(Callee, DAG);
 
   CallFlags CFlags(
       CallConv, isTailCall, isVarArg, isPatchPoint,
       isIndirectCall(Callee, DAG, Subtarget, isPatchPoint),
       // hasNest
       Subtarget.is64BitELFABI() &&
           any_of(Outs, [](ISD::OutputArg Arg) { return Arg.Flags.isNest(); }));
 
   if (Subtarget.isSVR4ABI() && Subtarget.isPPC64())
     return LowerCall_64SVR4(Chain, Callee, CFlags, Outs, OutVals, Ins, dl, DAG,
-                            InVals, CS);
+                            InVals, CB);
 
   if (Subtarget.isSVR4ABI())
     return LowerCall_32SVR4(Chain, Callee, CFlags, Outs, OutVals, Ins, dl, DAG,
-                            InVals, CS);
+                            InVals, CB);
 
   if (Subtarget.isAIXABI())
     return LowerCall_AIX(Chain, Callee, CFlags, Outs, OutVals, Ins, dl, DAG,
-                         InVals, CS);
+                         InVals, CB);
 
   return LowerCall_Darwin(Chain, Callee, CFlags, Outs, OutVals, Ins, dl, DAG,
-                          InVals, CS);
+                          InVals, CB);
 }
 
 SDValue PPCTargetLowering::LowerCall_32SVR4(
     SDValue Chain, SDValue Callee, CallFlags CFlags,
     const SmallVectorImpl<ISD::OutputArg> &Outs,
     const SmallVectorImpl<SDValue> &OutVals,
     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
-    ImmutableCallSite CS) const {
+    const CallBase *CB) const {
   // See PPCTargetLowering::LowerFormalArguments_32SVR4() for a description
   // of the 32-bit SVR4 ABI stack frame layout.
 
   const CallingConv::ID CallConv = CFlags.CallConv;
   const bool IsVarArg = CFlags.IsVarArg;
   const bool IsTailCall = CFlags.IsTailCall;
 
   assert((CallConv == CallingConv::C ||
if (IsVarArg) {
     InFlag = Chain.getValue(1);
   }
 
   if (IsTailCall)
     PrepareTailCall(DAG, InFlag, Chain, dl, SPDiff, NumBytes, LROp, FPOp,
                     TailCallArguments);
 
   return FinishCall(CFlags, dl, DAG, RegsToPass, InFlag, Chain, CallSeqStart,
-                    Callee, SPDiff, NumBytes, Ins, InVals, CS);
+                    Callee, SPDiff, NumBytes, Ins, InVals, CB);
 }
 
 // Copy an argument into memory, being careful to do this outside the
 // call sequence for the call to which the argument belongs.
 SDValue PPCTargetLowering::createMemcpyOutsideCallSeq(
     SDValue Arg, SDValue PtrOff, SDValue CallSeqStart, ISD::ArgFlagsTy Flags,
     SelectionDAG &DAG, const SDLoc &dl) const {
   SDValue MemcpyCall = CreateCopyOfByValArgument(Arg, PtrOff,

 }
 
 SDValue PPCTargetLowering::LowerCall_64SVR4(
     SDValue Chain, SDValue Callee, CallFlags CFlags,
     const SmallVectorImpl<ISD::OutputArg> &Outs,
     const SmallVectorImpl<SDValue> &OutVals,
     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
-    ImmutableCallSite CS) const {
+    const CallBase *CB) const {
   bool isELFv2ABI = Subtarget.isELFv2ABI();
   bool isLittleEndian = Subtarget.isLittleEndian();
   unsigned NumOps = Outs.size();
   bool IsSibCall = false;
   bool IsFastCall = CFlags.CallConv == CallingConv::Fast;
 
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
   unsigned PtrByteSize = 8;
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
     InFlag = Chain.getValue(1);
   }
 
   if (CFlags.IsTailCall && !IsSibCall)
     PrepareTailCall(DAG, InFlag, Chain, dl, SPDiff, NumBytes, LROp, FPOp,
                     TailCallArguments);
 
   return FinishCall(CFlags, dl, DAG, RegsToPass, InFlag, Chain, CallSeqStart,
-                    Callee, SPDiff, NumBytes, Ins, InVals, CS);
+                    Callee, SPDiff, NumBytes, Ins, InVals, CB);
 }
 
 SDValue PPCTargetLowering::LowerCall_Darwin(
     SDValue Chain, SDValue Callee, CallFlags CFlags,
     const SmallVectorImpl<ISD::OutputArg> &Outs,
     const SmallVectorImpl<SDValue> &OutVals,
     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
-    ImmutableCallSite CS) const {
+    const CallBase *CB) const {
   unsigned NumOps = Outs.size();
 
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
   bool isPPC64 = PtrVT == MVT::i64;
   unsigned PtrByteSize = isPPC64 ? 8 : 4;
 
   MachineFunction &MF = DAG.getMachineFunction();
 
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
     InFlag = Chain.getValue(1);
   }
 
   if (CFlags.IsTailCall)
     PrepareTailCall(DAG, InFlag, Chain, dl, SPDiff, NumBytes, LROp, FPOp,
                     TailCallArguments);
 
   return FinishCall(CFlags, dl, DAG, RegsToPass, InFlag, Chain, CallSeqStart,
-                    Callee, SPDiff, NumBytes, Ins, InVals, CS);
+                    Callee, SPDiff, NumBytes, Ins, InVals, CB);
 }
 
 static bool CC_AIX(unsigned ValNo, MVT ValVT, MVT LocVT,
                    CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
                    CCState &State) {
 
   const PPCSubtarget &Subtarget = static_cast<const PPCSubtarget &>(
       State.getMachineFunction().getSubtarget());

 }
 
 SDValue PPCTargetLowering::LowerCall_AIX(
     SDValue Chain, SDValue Callee, CallFlags CFlags,
     const SmallVectorImpl<ISD::OutputArg> &Outs,
     const SmallVectorImpl<SDValue> &OutVals,
     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
-    ImmutableCallSite CS) const {
+    const CallBase *CB) const {
 
   assert((CFlags.CallConv == CallingConv::C ||
           CFlags.CallConv == CallingConv::Cold ||
           CFlags.CallConv == CallingConv::Fast) &&
          "Unexpected calling convention!");
 
   if (CFlags.IsPatchPoint)
     report_fatal_error("This call type is unimplemented on AIX.");
SDValue PPCTargetLowering::LowerCall_AIX(
   SDValue InFlag;
   for (auto Reg : RegsToPass) {
     Chain = DAG.getCopyToReg(Chain, dl, Reg.first, Reg.second, InFlag);
     InFlag = Chain.getValue(1);
   }
 
   const int SPDiff = 0;
   return FinishCall(CFlags, dl, DAG, RegsToPass, InFlag, Chain, CallSeqStart,
-                    Callee, SPDiff, NumBytes, Ins, InVals, CS);
+                    Callee, SPDiff, NumBytes, Ins, InVals, CB);
 }
 
 bool
 PPCTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
                                   MachineFunction &MF, bool isVarArg,
                                   const SmallVectorImpl<ISD::OutputArg> &Outs,
                                   LLVMContext &Context) const {
   SmallVector<CCValAssign, 16> RVLocs;

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

else
     analyzeOutputArgs(MF, ArgCCInfo, Outs, /*IsRet=*/false, &CLI);
 
   // Check if it's really possible to do a tail call.
   if (IsTailCall)
     IsTailCall = isEligibleForTailCallOptimization(ArgCCInfo, CLI, MF, ArgLocs);
 
   if (IsTailCall)
     ++NumTailCalls;
-  else if (CLI.CS && CLI.CS.isMustTailCall())
+  else if (CLI.CB && CLI.CB->isMustTailCall())
     report_fatal_error("failed to perform tail call elimination on a call "
                        "site marked musttail");
 
   // Get a count of how many bytes are to be pushed on the stack.
   unsigned NumBytes = ArgCCInfo.getNextStackOffset();
 
   // Create local copies for byval args
   SmallVector<SDValue, 8> ByValArgs;

llvm/lib/Target/Sparc/SparcISelLowering.cpp

 SparcTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
                                SmallVectorImpl<SDValue> &InVals) const {
   if (Subtarget->is64Bit())
     return LowerCall_64(CLI, InVals);
   return LowerCall_32(CLI, InVals);
 }
 
 static bool hasReturnsTwiceAttr(SelectionDAG &DAG, SDValue Callee,
-                                ImmutableCallSite CS) {
-  if (CS)
-    return CS.hasFnAttr(Attribute::ReturnsTwice);
+                                const CallBase *Call) {
+  if (Call)
+    return Call->hasFnAttr(Attribute::ReturnsTwice);
 
   const Function *CalleeFn = nullptr;
   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
     CalleeFn = dyn_cast<Function>(G->getGlobal());
   } else if (ExternalSymbolSDNode *E =
              dyn_cast<ExternalSymbolSDNode>(Callee)) {
     const Function &Fn = DAG.getMachineFunction().getFunction();
     const Module *M = Fn.getParent();
SparcTargetLowering::LowerCall_32(TargetLowering::CallLoweringInfo &CLI,
   // stuck together.
   SDValue InFlag;
   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
     unsigned Reg = toCallerWindow(RegsToPass[i].first);
     Chain = DAG.getCopyToReg(Chain, dl, Reg, RegsToPass[i].second, InFlag);
     InFlag = Chain.getValue(1);
   }
 
-  bool hasReturnsTwice = hasReturnsTwiceAttr(DAG, Callee, CLI.CS);
+  bool hasReturnsTwice = hasReturnsTwiceAttr(DAG, Callee, CLI.CB);
 
   // If the callee is a GlobalAddress node (quite common, every direct call is)
   // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
   // Likewise ExternalSymbol -> TargetExternalSymbol.
   unsigned TF = isPositionIndependent() ? SparcMCExpr::VK_Sparc_WPLT30 : 0;
   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
     Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i32, 0, TF);
   else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
Chain = DAG.getCopyToReg(Chain, DL,
                              RegsToPass[i].first, RegsToPass[i].second, InGlue);
     InGlue = Chain.getValue(1);
   }
 
   // If the callee is a GlobalAddress node (quite common, every direct call is)
   // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
   // Likewise ExternalSymbol -> TargetExternalSymbol.
   SDValue Callee = CLI.Callee;
-  bool hasReturnsTwice = hasReturnsTwiceAttr(DAG, Callee, CLI.CS);
+  bool hasReturnsTwice = hasReturnsTwiceAttr(DAG, Callee, CLI.CB);
   unsigned TF = isPositionIndependent() ? SparcMCExpr::VK_Sparc_WPLT30 : 0;
   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
     Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL, PtrVT, 0, TF);
   else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
     Callee = DAG.getTargetExternalSymbol(E->getSymbol(), PtrVT, TF);
 
   // Build the operands for the call instruction itself.
   SmallVector<SDValue, 8> Ops;
SparcTargetLowering::LowerCall_64(TargetLowering::CallLoweringInfo &CLI,
 
   // Assign locations to each value returned by this call.
   SmallVector<CCValAssign, 16> RVLocs;
   CCState RVInfo(CLI.CallConv, CLI.IsVarArg, DAG.getMachineFunction(), RVLocs,
                  *DAG.getContext());
 
   // Set inreg flag manually for codegen generated library calls that
   // return float.
-  if (CLI.Ins.size() == 1 && CLI.Ins[0].VT == MVT::f32 && !CLI.CS)
+  if (CLI.Ins.size() == 1 && CLI.Ins[0].VT == MVT::f32 && !CLI.CB)
     CLI.Ins[0].Flags.setInReg();
 
   RVInfo.AnalyzeCallResult(CLI.Ins, RetCC_Sparc64);
 
   // Copy all of the result registers out of their specified physreg.
   for (unsigned i = 0; i != RVLocs.size(); ++i) {
     CCValAssign &VA = RVLocs[i];
     unsigned Reg = toCallerWindow(VA.getLocReg());

llvm/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp

if (!callingConvSupported(CallConv))
     fail(DL, DAG,
          "WebAssembly doesn't support language-specific or target-specific "
          "calling conventions yet");
   if (CLI.IsPatchPoint)
     fail(DL, DAG, "WebAssembly doesn't support patch point yet");
 
   if (CLI.IsTailCall) {
     auto NoTail = [&](const char *Msg) {
-      if (CLI.CS && CLI.CS.isMustTailCall())
+      if (CLI.CB && CLI.CB->isMustTailCall())
         fail(DL, DAG, Msg);
       CLI.IsTailCall = false;
     };
 
     if (!Subtarget->hasTailCall())
       NoTail("WebAssembly 'tail-call' feature not enabled");
 
     // Varargs calls cannot be tail calls because the buffer is on the stack
if (CLI.IsTailCall) {
     bool TypesMatch = CallerRetTys.size() == CalleeRetTys.size() &&
                       std::equal(CallerRetTys.begin(), CallerRetTys.end(),
                                  CalleeRetTys.begin());
     if (!TypesMatch)
       NoTail("WebAssembly tail call requires caller and callee return types to "
              "match");
 
     // If pointers to local stack values are passed, we cannot tail call
-    if (CLI.CS) {
-      for (auto &Arg : CLI.CS.args()) {
+    if (CLI.CB) {
+      for (auto &Arg : CLI.CB->args()) {
         Value *Val = Arg.get();
         // Trace the value back through pointer operations
         while (true) {
           Value *Src = Val->stripPointerCastsAndAliases();
           if (auto *GEP = dyn_cast<GetElementPtrInst>(Src))
             Src = GEP->getPointerOperand();
           if (Val == Src)
             break;

llvm/lib/Target/X86/X86ISelLowering.cpp

X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   MachineFunction &MF = DAG.getMachineFunction();
   bool Is64Bit        = Subtarget.is64Bit();
   bool IsWin64        = Subtarget.isCallingConvWin64(CallConv);
   StructReturnType SR = callIsStructReturn(Outs, Subtarget.isTargetMCU());
   bool IsSibcall      = false;
   bool IsGuaranteeTCO = MF.getTarget().Options.GuaranteedTailCallOpt ||
       CallConv == CallingConv::Tail;
   X86MachineFunctionInfo *X86Info = MF.getInfo<X86MachineFunctionInfo>();
-  const auto *CI = dyn_cast_or_null<CallInst>(CLI.CS.getInstruction());
+  const auto *CI = dyn_cast_or_null<CallInst>(CLI.CB);
   const Function *Fn = CI ? CI->getCalledFunction() : nullptr;
   bool HasNCSR = (CI && CI->hasFnAttr("no_caller_saved_registers")) ||
                  (Fn && Fn->hasFnAttribute("no_caller_saved_registers"));
-  const auto *II = dyn_cast_or_null<InvokeInst>(CLI.CS.getInstruction());
+  const auto *II = dyn_cast_or_null<InvokeInst>(CLI.CB);
   bool HasNoCfCheck =
       (CI && CI->doesNoCfCheck()) || (II && II->doesNoCfCheck());
   const Module *M = MF.getMMI().getModule();
   Metadata *IsCFProtectionSupported = M->getModuleFlag("cf-protection-branch");
 
   MachineFunction::CallSiteInfo CSInfo;
 
   if (CallConv == CallingConv::X86_INTR)
     report_fatal_error("X86 interrupts may not be called directly");
 
   if (Subtarget.isPICStyleGOT() && !IsGuaranteeTCO) {
     // If we are using a GOT, disable tail calls to external symbols with
     // default visibility. Tail calling such a symbol requires using a GOT
     // relocation, which forces early binding of the symbol. This breaks code
     // that require lazy function symbol resolution. Using musttail or
     // GuaranteedTailCallOpt will override this.
     GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
     if (!G || (!G->getGlobal()->hasLocalLinkage() &&
                G->getGlobal()->hasDefaultVisibility()))
       isTailCall = false;
   }
 
-  bool IsMustTail = CLI.CS && CLI.CS.isMustTailCall();
+  bool IsMustTail = CLI.CB && CLI.CB->isMustTailCall();
   if (IsMustTail) {
     // Force this to be a tail call.  The verifier rules are enough to ensure
     // that we can lower this successfully without moving the return address
     // around.
     isTailCall = true;
   } else if (isTailCall) {
     // Check if it's really possible to do a tail call.
     isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv,
const uint32_t *Mask = RegInfo->getCallPreservedMask(
       MF, HasNCSR ? (CallingConv::ID)CallingConv::X86_INTR : CallConv);
   assert(Mask && "Missing call preserved mask for calling convention");
 
   // If this is an invoke in a 32-bit function using a funclet-based
   // personality, assume the function clobbers all registers. If an exception
   // is thrown, the runtime will not restore CSRs.
   // FIXME: Model this more precisely so that we can register allocate across
   // the normal edge and spill and fill across the exceptional edge.
-  if (!Is64Bit && CLI.CS && CLI.CS.isInvoke()) {
+  if (!Is64Bit && CLI.CB && isa<InvokeInst>(CLI.CB)) {
     const Function &CallerFn = MF.getFunction();
     EHPersonality Pers =
         CallerFn.hasPersonalityFn()
             ? classifyEHPersonality(CallerFn.getPersonalityFn())
             : EHPersonality::Unknown;
     if (isFuncletEHPersonality(Pers))
       Mask = RegInfo->getNoPreservedMask();
   }
if (HasNoCfCheck && IsCFProtectionSupported) {
     Chain = DAG.getNode(X86ISD::NT_CALL, dl, NodeTys, Ops);
   } else {
     Chain = DAG.getNode(X86ISD::CALL, dl, NodeTys, Ops);
   }
   InFlag = Chain.getValue(1);
   DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
 
   // Save heapallocsite metadata.
-  if (CLI.CS)
-    if (MDNode *HeapAlloc = CLI.CS->getMetadata("heapallocsite"))
+  if (CLI.CB)
+    if (MDNode *HeapAlloc = CLI.CB->getMetadata("heapallocsite"))
       DAG.addHeapAllocSite(Chain.getNode(), HeapAlloc);
 
   // Create the CALLSEQ_END node.
   unsigned NumBytesForCalleeToPop;
   if (X86::isCalleePop(CallConv, Is64Bit, isVarArg,
                        DAG.getTarget().Options.GuaranteedTailCallOpt))
     NumBytesForCalleeToPop = NumBytes;    // Callee pops everything
   else if (!Is64Bit && !canGuaranteeTCO(CallConv) &&