C++ InvokeInst::setCallingConv方法代码示例

// visitCallInst - This converts all LLVM call instructions into invoke
// instructions. The except part of the invoke goes to the "LongJmpBlkPre"
// that grabs the exception and proceeds to determine if it's a longjmp
// exception or not.
void LowerSetJmp::visitCallInst(CallInst& CI)
{
  if (CI.getCalledFunction())
    if (!IsTransformableFunction(CI.getCalledFunction()->getName()) ||
        CI.getCalledFunction()->isIntrinsic()) return;

  BasicBlock* OldBB = CI.getParent();

  // If not reachable from a setjmp call, don't transform.
  if (!DFSBlocks.count(OldBB)) return;

  BasicBlock* NewBB = OldBB->splitBasicBlock(CI);
  assert(NewBB && "Couldn't split BB of \"call\" instruction!!");
  DFSBlocks.insert(NewBB);
  NewBB->setName("Call2Invoke");

  Function* Func = OldBB->getParent();

  // Construct the new "invoke" instruction.
  TerminatorInst* Term = OldBB->getTerminator();
  std::vector<Value*> Params(CI.op_begin() + 1, CI.op_end());
  InvokeInst* II =
    InvokeInst::Create(CI.getCalledValue(), NewBB, PrelimBBMap[Func],
                       Params.begin(), Params.end(), CI.getName(), Term);
  II->setCallingConv(CI.getCallingConv());
  II->setParamAttrs(CI.getParamAttrs());

  // Replace the old call inst with the invoke inst and remove the call.
  CI.replaceAllUsesWith(II);
  CI.getParent()->getInstList().erase(&CI);

  // The old terminator is useless now that we have the invoke inst.
  Term->getParent()->getInstList().erase(Term);
  ++CallsTransformed;
}

/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
/// an invoke, we have to turn all of the calls that can throw into
/// invokes.  This function analyze BB to see if there are any calls, and if so,
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
/// nodes in that block with the values specified in InvokeDestPHIValues.
///
/// Returns true to indicate that the next block should be skipped.
static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
                                                   InvokeInliningInfo &Invoke) {
  LandingPadInst *LPI = Invoke.getLandingPadInst();

  for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
    Instruction *I = BBI++;

    if (LandingPadInst *L = dyn_cast<LandingPadInst>(I)) {
      unsigned NumClauses = LPI->getNumClauses();
      L->reserveClauses(NumClauses);
      for (unsigned i = 0; i != NumClauses; ++i)
        L->addClause(LPI->getClause(i));
    }

    // We only need to check for function calls: inlined invoke
    // instructions require no special handling.
    CallInst *CI = dyn_cast<CallInst>(I);

    // If this call cannot unwind, don't convert it to an invoke.
    // Inline asm calls cannot throw.
    if (!CI || CI->doesNotThrow() || isa<InlineAsm>(CI->getCalledValue()))
      continue;

    // Convert this function call into an invoke instruction.  First, split the
    // basic block.
    BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");

    // Delete the unconditional branch inserted by splitBasicBlock
    BB->getInstList().pop_back();

    // Create the new invoke instruction.
    ImmutableCallSite CS(CI);
    SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
    InvokeInst *II = InvokeInst::Create(CI->getCalledValue(), Split,
                                        Invoke.getOuterResumeDest(),
                                        InvokeArgs, CI->getName(), BB);
    II->setCallingConv(CI->getCallingConv());
    II->setAttributes(CI->getAttributes());
    
    // Make sure that anything using the call now uses the invoke!  This also
    // updates the CallGraph if present, because it uses a WeakVH.
    CI->replaceAllUsesWith(II);

    // Delete the original call
    Split->getInstList().pop_front();

    // Update any PHI nodes in the exceptional block to indicate that there is
    // now a new entry in them.
    Invoke.addIncomingPHIValuesFor(BB);
    return false;
  }

  return false;
}

/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
/// an invoke, we have to turn all of the calls that can throw into
/// invokes.  This function analyze BB to see if there are any calls, and if so,
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
/// nodes in that block with the values specified in InvokeDestPHIValues.
///
static void HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
                                                   BasicBlock *InvokeDest,
                           const SmallVectorImpl<Value*> &InvokeDestPHIValues) {
  for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
    Instruction *I = BBI++;
    
    // We only need to check for function calls: inlined invoke
    // instructions require no special handling.
    CallInst *CI = dyn_cast<CallInst>(I);
    if (CI == 0) continue;
    
    // If this call cannot unwind, don't convert it to an invoke.
    if (CI->doesNotThrow())
      continue;
    
    // Convert this function call into an invoke instruction.
    // First, split the basic block.
    BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");
    
    // Next, create the new invoke instruction, inserting it at the end
    // of the old basic block.
    ImmutableCallSite CS(CI);
    SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
    InvokeInst *II =
      InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest,
                         InvokeArgs.begin(), InvokeArgs.end(),
                         CI->getName(), BB->getTerminator());
    II->setCallingConv(CI->getCallingConv());
    II->setAttributes(CI->getAttributes());
    
    // Make sure that anything using the call now uses the invoke!  This also
    // updates the CallGraph if present, because it uses a WeakVH.
    CI->replaceAllUsesWith(II);
    
    // Delete the unconditional branch inserted by splitBasicBlock
    BB->getInstList().pop_back();
    Split->getInstList().pop_front();  // Delete the original call
    
    // Update any PHI nodes in the exceptional block to indicate that
    // there is now a new entry in them.
    unsigned i = 0;
    for (BasicBlock::iterator I = InvokeDest->begin();
         isa<PHINode>(I); ++I, ++i)
      cast<PHINode>(I)->addIncoming(InvokeDestPHIValues[i], BB);
    
    // This basic block is now complete, the caller will continue scanning the
    // next one.
    return;
  }
}

/// Replaces the given call site (Call or Invoke) with a gc.statepoint
/// intrinsic with an empty deoptimization arguments list.  This does
/// NOT do explicit relocation for GC support.
static Value *ReplaceWithStatepoint(const CallSite &CS /* to replace */) {
  assert(CS.getInstruction()->getModule() && "must be set");

  // TODO: technically, a pass is not allowed to get functions from within a
  // function pass since it might trigger a new function addition.  Refactor
  // this logic out to the initialization of the pass.  Doesn't appear to
  // matter in practice.

  // Then go ahead and use the builder do actually do the inserts.  We insert
  // immediately before the previous instruction under the assumption that all
  // arguments will be available here.  We can't insert afterwards since we may
  // be replacing a terminator.
  IRBuilder<> Builder(CS.getInstruction());

  // Note: The gc args are not filled in at this time, that's handled by
  // RewriteStatepointsForGC (which is currently under review).

  // Create the statepoint given all the arguments
  Instruction *Token = nullptr;

  uint64_t ID;
  uint32_t NumPatchBytes;

  AttributeSet OriginalAttrs = CS.getAttributes();
  Attribute AttrID =
      OriginalAttrs.getAttribute(AttributeSet::FunctionIndex, "statepoint-id");
  Attribute AttrNumPatchBytes = OriginalAttrs.getAttribute(
      AttributeSet::FunctionIndex, "statepoint-num-patch-bytes");

  AttrBuilder AttrsToRemove;
  bool HasID = AttrID.isStringAttribute() &&
               !AttrID.getValueAsString().getAsInteger(10, ID);

  if (HasID)
    AttrsToRemove.addAttribute("statepoint-id");
  else
    ID = 0xABCDEF00;

  bool HasNumPatchBytes =
      AttrNumPatchBytes.isStringAttribute() &&
      !AttrNumPatchBytes.getValueAsString().getAsInteger(10, NumPatchBytes);

  if (HasNumPatchBytes)
    AttrsToRemove.addAttribute("statepoint-num-patch-bytes");
  else
    NumPatchBytes = 0;

  OriginalAttrs = OriginalAttrs.removeAttributes(
      CS.getInstruction()->getContext(), AttributeSet::FunctionIndex,
      AttrsToRemove);

  if (CS.isCall()) {
    CallInst *ToReplace = cast<CallInst>(CS.getInstruction());
    CallInst *Call = Builder.CreateGCStatepointCall(
        ID, NumPatchBytes, CS.getCalledValue(),
        makeArrayRef(CS.arg_begin(), CS.arg_end()), None, None,
        "safepoint_token");
    Call->setTailCall(ToReplace->isTailCall());
    Call->setCallingConv(ToReplace->getCallingConv());

    // In case if we can handle this set of attributes - set up function
    // attributes directly on statepoint and return attributes later for
    // gc_result intrinsic.
    Call->setAttributes(OriginalAttrs.getFnAttributes());

    Token = Call;

    // Put the following gc_result and gc_relocate calls immediately after
    // the old call (which we're about to delete).
    assert(ToReplace->getNextNode() && "not a terminator, must have next");
    Builder.SetInsertPoint(ToReplace->getNextNode());
    Builder.SetCurrentDebugLocation(ToReplace->getNextNode()->getDebugLoc());
  } else if (CS.isInvoke()) {
    InvokeInst *ToReplace = cast<InvokeInst>(CS.getInstruction());

    // Insert the new invoke into the old block.  We'll remove the old one in a
    // moment at which point this will become the new terminator for the
    // original block.
    Builder.SetInsertPoint(ToReplace->getParent());
    InvokeInst *Invoke = Builder.CreateGCStatepointInvoke(
        ID, NumPatchBytes, CS.getCalledValue(), ToReplace->getNormalDest(),
        ToReplace->getUnwindDest(), makeArrayRef(CS.arg_begin(), CS.arg_end()),
        None, None, "safepoint_token");

    Invoke->setCallingConv(ToReplace->getCallingConv());

    // In case if we can handle this set of attributes - set up function
    // attributes directly on statepoint and return attributes later for
    // gc_result intrinsic.
    Invoke->setAttributes(OriginalAttrs.getFnAttributes());

    Token = Invoke;

    // We'll insert the gc.result into the normal block
    BasicBlock *NormalDest = ToReplace->getNormalDest();
    // Can not insert gc.result in case of phi nodes preset.
    // Should have removed this cases prior to running this function
//.........这里部分代码省略.........

/// HandleInlinedInvoke - If we inlined an invoke site, we need to convert calls
/// in the body of the inlined function into invokes and turn unwind
/// instructions into branches to the invoke unwind dest.
///
/// II is the invoke instruction being inlined.  FirstNewBlock is the first
/// block of the inlined code (the last block is the end of the function),
/// and InlineCodeInfo is information about the code that got inlined.
static void HandleInlinedInvoke(InvokeInst *II, BasicBlock *FirstNewBlock,
                                ClonedCodeInfo &InlinedCodeInfo) {
  BasicBlock *InvokeDest = II->getUnwindDest();
  std::vector<Value*> InvokeDestPHIValues;

  // If there are PHI nodes in the unwind destination block, we need to
  // keep track of which values came into them from this invoke, then remove
  // the entry for this block.
  BasicBlock *InvokeBlock = II->getParent();
  for (BasicBlock::iterator I = InvokeDest->begin(); isa<PHINode>(I); ++I) {
    PHINode *PN = cast<PHINode>(I);
    // Save the value to use for this edge.
    InvokeDestPHIValues.push_back(PN->getIncomingValueForBlock(InvokeBlock));
  }

  Function *Caller = FirstNewBlock->getParent();

  // The inlined code is currently at the end of the function, scan from the
  // start of the inlined code to its end, checking for stuff we need to
  // rewrite.
  if (InlinedCodeInfo.ContainsCalls || InlinedCodeInfo.ContainsUnwinds) {
    for (Function::iterator BB = FirstNewBlock, E = Caller->end();
         BB != E; ++BB) {
      if (InlinedCodeInfo.ContainsCalls) {
        for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ){
          Instruction *I = BBI++;

          // We only need to check for function calls: inlined invoke
          // instructions require no special handling.
          if (!isa<CallInst>(I)) continue;
          CallInst *CI = cast<CallInst>(I);

          // If this call cannot unwind, don't convert it to an invoke.
          if (CI->doesNotThrow())
            continue;

          // Convert this function call into an invoke instruction.
          // First, split the basic block.
          BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");

          // Next, create the new invoke instruction, inserting it at the end
          // of the old basic block.
          SmallVector<Value*, 8> InvokeArgs(CI->op_begin()+1, CI->op_end());
          InvokeInst *II =
            InvokeInst::Create(CI->getCalledValue(), Split, InvokeDest,
                               InvokeArgs.begin(), InvokeArgs.end(),
                               CI->getName(), BB->getTerminator());
          II->setCallingConv(CI->getCallingConv());
          II->setAttributes(CI->getAttributes());

          // Make sure that anything using the call now uses the invoke!
          CI->replaceAllUsesWith(II);

          // Delete the unconditional branch inserted by splitBasicBlock
          BB->getInstList().pop_back();
          Split->getInstList().pop_front();  // Delete the original call

          // Update any PHI nodes in the exceptional block to indicate that
          // there is now a new entry in them.
          unsigned i = 0;
          for (BasicBlock::iterator I = InvokeDest->begin();
               isa<PHINode>(I); ++I, ++i) {
            PHINode *PN = cast<PHINode>(I);
            PN->addIncoming(InvokeDestPHIValues[i], BB);
          }

          // This basic block is now complete, start scanning the next one.
          break;
        }
      }

      if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
        // An UnwindInst requires special handling when it gets inlined into an
        // invoke site.  Once this happens, we know that the unwind would cause
        // a control transfer to the invoke exception destination, so we can
        // transform it into a direct branch to the exception destination.
        BranchInst::Create(InvokeDest, UI);

        // Delete the unwind instruction!
        UI->eraseFromParent();

        // Update any PHI nodes in the exceptional block to indicate that
        // there is now a new entry in them.
        unsigned i = 0;
        for (BasicBlock::iterator I = InvokeDest->begin();
             isa<PHINode>(I); ++I, ++i) {
          PHINode *PN = cast<PHINode>(I);
          PN->addIncoming(InvokeDestPHIValues[i], BB);
        }
      }
    }
  }

//.........这里部分代码省略.........

/// Replaces the given call site (Call or Invoke) with a gc.statepoint
/// intrinsic with an empty deoptimization arguments list.  This does
/// NOT do explicit relocation for GC support.
static Value *ReplaceWithStatepoint(const CallSite &CS, /* to replace */
                                    Pass *P) {
  BasicBlock *BB = CS.getInstruction()->getParent();
  Function *F = BB->getParent();
  Module *M = F->getParent();
  assert(M && "must be set");

  // TODO: technically, a pass is not allowed to get functions from within a
  // function pass since it might trigger a new function addition.  Refactor
  // this logic out to the initialization of the pass.  Doesn't appear to
  // matter in practice.

  // Fill in the one generic type'd argument (the function is also vararg)
  std::vector<Type *> argTypes;
  argTypes.push_back(CS.getCalledValue()->getType());

  Function *gc_statepoint_decl = Intrinsic::getDeclaration(
      M, Intrinsic::experimental_gc_statepoint, argTypes);

  // Then go ahead and use the builder do actually do the inserts.  We insert
  // immediately before the previous instruction under the assumption that all
  // arguments will be available here.  We can't insert afterwards since we may
  // be replacing a terminator.
  Instruction *insertBefore = CS.getInstruction();
  IRBuilder<> Builder(insertBefore);
  // First, create the statepoint (with all live ptrs as arguments).
  std::vector<llvm::Value *> args;
  // target, #args, unused, args
  Value *Target = CS.getCalledValue();
  args.push_back(Target);
  int callArgSize = CS.arg_size();
  args.push_back(
      ConstantInt::get(Type::getInt32Ty(M->getContext()), callArgSize));
  // TODO: add a 'Needs GC-rewrite' later flag
  args.push_back(ConstantInt::get(Type::getInt32Ty(M->getContext()), 0));

  // Copy all the arguments of the original call
  args.insert(args.end(), CS.arg_begin(), CS.arg_end());

  // Create the statepoint given all the arguments
  Instruction *token = nullptr;
  AttributeSet return_attributes;
  if (CS.isCall()) {
    CallInst *toReplace = cast<CallInst>(CS.getInstruction());
    CallInst *call =
        Builder.CreateCall(gc_statepoint_decl, args, "safepoint_token");
    call->setTailCall(toReplace->isTailCall());
    call->setCallingConv(toReplace->getCallingConv());

    // Before we have to worry about GC semantics, all attributes are legal
    AttributeSet new_attrs = toReplace->getAttributes();
    // In case if we can handle this set of sttributes - set up function attrs
    // directly on statepoint and return attrs later for gc_result intrinsic.
    call->setAttributes(new_attrs.getFnAttributes());
    return_attributes = new_attrs.getRetAttributes();
    // TODO: handle param attributes

    token = call;

    // Put the following gc_result and gc_relocate calls immediately after the
    // the old call (which we're about to delete)
    BasicBlock::iterator next(toReplace);
    assert(BB->end() != next && "not a terminator, must have next");
    next++;
    Instruction *IP = &*(next);
    Builder.SetInsertPoint(IP);
    Builder.SetCurrentDebugLocation(IP->getDebugLoc());

  } else if (CS.isInvoke()) {
    InvokeInst *toReplace = cast<InvokeInst>(CS.getInstruction());

    // Insert the new invoke into the old block.  We'll remove the old one in a
    // moment at which point this will become the new terminator for the
    // original block.
    InvokeInst *invoke = InvokeInst::Create(
        gc_statepoint_decl, toReplace->getNormalDest(),
        toReplace->getUnwindDest(), args, "", toReplace->getParent());
    invoke->setCallingConv(toReplace->getCallingConv());

    // Currently we will fail on parameter attributes and on certain
    // function attributes.
    AttributeSet new_attrs = toReplace->getAttributes();
    // In case if we can handle this set of sttributes - set up function attrs
    // directly on statepoint and return attrs later for gc_result intrinsic.
    invoke->setAttributes(new_attrs.getFnAttributes());
    return_attributes = new_attrs.getRetAttributes();

    token = invoke;

    // We'll insert the gc.result into the normal block
    BasicBlock *normalDest = normalizeBBForInvokeSafepoint(
        toReplace->getNormalDest(), invoke->getParent());
    Instruction *IP = &*(normalDest->getFirstInsertionPt());
    Builder.SetInsertPoint(IP);
  } else {
    llvm_unreachable("unexpect type of CallSite");
  }
//.........这里部分代码省略.........

/// HandleCallsInBlockInlinedThroughInvoke - When we inline a basic block into
/// an invoke, we have to turn all of the calls that can throw into
/// invokes.  This function analyze BB to see if there are any calls, and if so,
/// it rewrites them to be invokes that jump to InvokeDest and fills in the PHI
/// nodes in that block with the values specified in InvokeDestPHIValues.
///
/// Returns true to indicate that the next block should be skipped.
static bool HandleCallsInBlockInlinedThroughInvoke(BasicBlock *BB,
                                                   InvokeInliningInfo &Invoke) {
  for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
    Instruction *I = BBI++;
    
    // We only need to check for function calls: inlined invoke
    // instructions require no special handling.
    CallInst *CI = dyn_cast<CallInst>(I);
    if (CI == 0) continue;

    // LIBUNWIND: merge selector instructions.
    if (EHSelectorInst *Inner = dyn_cast<EHSelectorInst>(CI)) {
      EHSelectorInst *Outer = Invoke.getOuterSelector();
      if (!Outer) continue;

      bool innerIsOnlyCleanup = isCleanupOnlySelector(Inner);
      bool outerIsOnlyCleanup = isCleanupOnlySelector(Outer);

      // If both selectors contain only cleanups, we don't need to do
      // anything.  TODO: this is really just a very specific instance
      // of a much more general optimization.
      if (innerIsOnlyCleanup && outerIsOnlyCleanup) continue;

      // Otherwise, we just append the outer selector to the inner selector.
      SmallVector<Value*, 16> NewSelector;
      for (unsigned i = 0, e = Inner->getNumArgOperands(); i != e; ++i)
        NewSelector.push_back(Inner->getArgOperand(i));
      for (unsigned i = 2, e = Outer->getNumArgOperands(); i != e; ++i)
        NewSelector.push_back(Outer->getArgOperand(i));

      CallInst *NewInner =
        IRBuilder<>(Inner).CreateCall(Inner->getCalledValue(), NewSelector);
      // No need to copy attributes, calling convention, etc.
      NewInner->takeName(Inner);
      Inner->replaceAllUsesWith(NewInner);
      Inner->eraseFromParent();
      continue;
    }
    
    // If this call cannot unwind, don't convert it to an invoke.
    if (CI->doesNotThrow())
      continue;
    
    // Convert this function call into an invoke instruction.
    // First, split the basic block.
    BasicBlock *Split = BB->splitBasicBlock(CI, CI->getName()+".noexc");

    // Delete the unconditional branch inserted by splitBasicBlock
    BB->getInstList().pop_back();

    // LIBUNWIND: If this is a call to @llvm.eh.resume, just branch
    // directly to the new landing pad.
    if (Invoke.forwardEHResume(CI, BB)) {
      // TODO: 'Split' is now unreachable; clean it up.

      // We want to leave the original call intact so that the call
      // graph and other structures won't get misled.  We also have to
      // avoid processing the next block, or we'll iterate here forever.
      return true;
    }

    // Otherwise, create the new invoke instruction.
    ImmutableCallSite CS(CI);
    SmallVector<Value*, 8> InvokeArgs(CS.arg_begin(), CS.arg_end());
    InvokeInst *II =
      InvokeInst::Create(CI->getCalledValue(), Split,
                         Invoke.getOuterUnwindDest(),
                         InvokeArgs, CI->getName(), BB);
    II->setCallingConv(CI->getCallingConv());
    II->setAttributes(CI->getAttributes());
    
    // Make sure that anything using the call now uses the invoke!  This also
    // updates the CallGraph if present, because it uses a WeakVH.
    CI->replaceAllUsesWith(II);

    Split->getInstList().pop_front();  // Delete the original call

    // Update any PHI nodes in the exceptional block to indicate that
    // there is now a new entry in them.
    Invoke.addIncomingPHIValuesFor(BB);
    return false;
  }

  return false;
}

// Convert the given call to use normalized argument/return types.
template <class T> static bool ConvertCall(T *Call, Pass *P) {
  // Don't try to change calls to intrinsics.
  if (isa<IntrinsicInst>(Call))
    return false;
  FunctionType *FTy = cast<FunctionType>(
      Call->getCalledValue()->getType()->getPointerElementType());
  FunctionType *NFTy = NormalizeFunctionType(FTy);
  if (NFTy == FTy)
    return false; // No change needed.

  // Convert arguments.
  SmallVector<Value *, 8> Args;
  for (unsigned I = 0; I < Call->getNumArgOperands(); ++I) {
    Value *Arg = Call->getArgOperand(I);
    if (NFTy->getParamType(I) != FTy->getParamType(I)) {
      Instruction::CastOps CastType =
          Call->getAttributes().hasAttribute(I + 1, Attribute::SExt) ?
          Instruction::SExt : Instruction::ZExt;
      Arg = CopyDebug(CastInst::Create(CastType, Arg, NFTy->getParamType(I),
                                       "arg_ext", Call), Call);
    }
    Args.push_back(Arg);
  }
  Value *CastFunc =
    CopyDebug(new BitCastInst(Call->getCalledValue(), NFTy->getPointerTo(),
                              Call->getName() + ".arg_cast", Call), Call);
  Value *Result = NULL;
  if (CallInst *OldCall = dyn_cast<CallInst>(Call)) {
    CallInst *NewCall = CopyDebug(CallInst::Create(CastFunc, Args, "", OldCall),
                                  OldCall);
    NewCall->takeName(OldCall);
    NewCall->setAttributes(OldCall->getAttributes());
    NewCall->setCallingConv(OldCall->getCallingConv());
    NewCall->setTailCall(OldCall->isTailCall());
    Result = NewCall;

    if (FTy->getReturnType() != NFTy->getReturnType()) {
      Result = CopyDebug(new TruncInst(NewCall, FTy->getReturnType(),
                                       NewCall->getName() + ".ret_trunc", Call),
                         Call);
    }
  } else if (InvokeInst *OldInvoke = dyn_cast<InvokeInst>(Call)) {
    BasicBlock *Parent = OldInvoke->getParent();
    BasicBlock *NormalDest = OldInvoke->getNormalDest();
    BasicBlock *UnwindDest = OldInvoke->getUnwindDest();

    if (FTy->getReturnType() != NFTy->getReturnType()) {
      if (BasicBlock *SplitDest = SplitCriticalEdge(Parent, NormalDest)) {
        NormalDest = SplitDest;
      }
    }

    InvokeInst *New = CopyDebug(InvokeInst::Create(CastFunc, NormalDest,
                                                   UnwindDest, Args,
                                                   "", OldInvoke),
                                OldInvoke);
    New->takeName(OldInvoke);

    if (FTy->getReturnType() != NFTy->getReturnType()) {
      Result = CopyDebug(new TruncInst(New, FTy->getReturnType(),
                                       New->getName() + ".ret_trunc",
                                       NormalDest->getTerminator()),
                         OldInvoke);
    } else {
      Result = New;
    }

    New->setAttributes(OldInvoke->getAttributes());
    New->setCallingConv(OldInvoke->getCallingConv());
  }
  Call->replaceAllUsesWith(Result);
  Call->eraseFromParent();
  return true;
}