[opaque pointer types] Add a FunctionCallee wrapper type, and use it.

[jyknight]

Summary

The FunctionCallee type is effectively a {FunctionType*,Value*} pair,
and is a useful convenience to enable code to continue passing the
result of getOrInsertFunction() through to EmitCall, even once pointer
types lose their pointee-type.

Then:

• update the CallInst/InvokeInst instruction creation functions to

take a Callee,

• modify getOrInsertFunction to return FunctionCallee, and
• update all callers appropriately.

One area of particular note is the change to the sanitizer
code. Previously, they had been casting the result of
getOrInsertFunction to a Function* via
checkSanitizerInterfaceFunction, and storing that. That would report
an error if someone had already inserted a function declaraction with
a mismatching signature.

However, in general, LLVM allows for such mismatches, as
getOrInsertFunction will automatically insert a bitcast if
needed. As part of this cleanup, cause the sanitizer code to do the
same. (It will call its functions using the expected signature,
however they may have been declared.)

Finally, in a small number of locations, callers of
getOrInsertFunction actually were expecting/requiring that a brand
new function was being created. In such cases, I've switched them to
Function::Create instead.

[dblaikie]

llvm/examples/HowToUseJIT/HowToUseJIT.cpp

71–74

Does this translation (of a getOrInsert cast to Function to a Function::Create) work (not assert, etc) if the Function with that specific name and type already does exist? (the old code would succeed at the cast - the new code, does Function::Create succeed even if the function already exists?)

llvm/include/llvm/IR/DerivedTypes.h

168

In the interim (until opaque pointers happen) would it be correct/reasonable to assert in here that the type of the Value is a pointer to the FnType?

171–172

If it's only these two, overloads might be simpler/clearer? (though I'm not super fussed if you have a clear preference for this form)

178

potentially use non static data member initializers and = default this default ctor? (& the ctor above could skip its member initializers since null would be the default)

llvm/include/llvm/IR/Instructions.h

1563–1564

Worth having these as overloads, or would it be simpler/reasonable to change callers who don't have a FunctionCallee, to pass the first two args as {x, y} (as a separate commit would be totally OK of course)

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

11753–11755

This one in particular wasn't changed to use Function::Create - perhaps this answers my previous question about whether Function::Create is OK for an existing function (in the sense that this code suggests it is not OK? hence why this code still uses getOrInsert)

11756

Previous code made this a cast, not a dyn_cast - any reason to change that? (that means this new condition probably isn't tested - no test ever fails this dyn_cast?)

[jyknight]

llvm/examples/HowToUseJIT/HowToUseJIT.cpp

71–74

The old code could succeed at the cast (when the signature matches) -- but would then proceed to add more basic blocks to a function that may have already been created! That's certainly no good.

Function::Create will unconditionally create a brand new function, giving it a different name, if the name is already in use. That may or may not be a reasonable thing to do, depending on the circumstance.

There's two such changes in non-example/unittest code, I've left a comment on each.

llvm/include/llvm/IR/DerivedTypes.h

168

I believe it would be correct. However, I don't have a definition of Value here, only a forward-decl.

There's already an assert in CallInst::Create that the type of the value matches the function type, which I think will catch the problem soon enough.

171–172

Explicit overloads here are tricky, because this file doesn't include Function.h and InlineAsm.h. And I can't put them in InlineAsm and Function because it's a conversion from pointer to those types, not from the type itself.

So, this seemed the simplest way to express it.

178

Good idea -- I'd forgotten those were allowed.

llvm/include/llvm/IR/Instructions.h

1563–1564

Good question. I'll not change this until the migration is all done. Then it may be worth checking if there's much need.

llvm/include/llvm/IR/Module.h

332

Oops, forgot this FIXME. :) Updated the comment.

llvm/lib/CodeGen/MIRParser/MIRParser.cpp

274

This is okay because it only gets called after line 291 determines that there's no existing function of that name.

llvm/lib/CodeGen/MachineOutliner.cpp

1107

The name of this function is irrelevant -- the code is creating both function and call, so if Function::Create renames it, that'd be fine. Additionally, the code above intended to choose a unique name already.

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

11753–11755

This uses getOrInsert because it's referencing an externally-provided function, not defining a new function.

11756

There are many instances like this in the codebase, where it dyn_cast's the thing returned from getOrInsertFunction to add add various attributes to it.

I do not like this scheme at all and would like to get rid of that idiom, but I don't want to fix it all of that as part of this particular change.

The change here is simply to make this code use the typical idiom.

clang/lib/CodeGen/CGExpr.cpp

void CodeGenFunction::EmitCfiSlowPathCheck(
   llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
   BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
 
   EmitBlock(CheckBB);
 
   bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
 
   llvm::CallInst *CheckCall;
-  llvm::Constant *SlowPathFn;
+  llvm::FunctionCallee SlowPathFn;
   if (WithDiag) {
     llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
     auto *InfoPtr =
         new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
                                  llvm::GlobalVariable::PrivateLinkage, Info);
     InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
     CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
 
     SlowPathFn = CGM.getModule().getOrInsertFunction(
         "__cfi_slowpath_diag",
         llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
                                 false));
     CheckCall = Builder.CreateCall(
         SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
   } else {
     SlowPathFn = CGM.getModule().getOrInsertFunction(
         "__cfi_slowpath",
         llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
     CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
   }
 
-  CGM.setDSOLocal(cast<llvm::GlobalValue>(SlowPathFn->stripPointerCasts()));
+  CGM.setDSOLocal(
+      cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
   CheckCall->setDoesNotThrow();
 
   EmitBlock(Cont);
 }
 
 // Emit a stub for __cfi_check function so that the linker knows about this
 // symbol in LTO mode.
 void CodeGenFunction::EmitCfiCheckStub() {

llvm/docs/ProgrammersManual.rst

 
 ----------------
 
 * ``Function *getFunction(StringRef Name) const``
 
   Look up the specified function in the ``Module`` SymbolTable_.  If it does not
   exist, return ``null``.
 
-* ``Function *getOrInsertFunction(const std::string &Name, const FunctionType
-  *T)``
+* ``FunctionCallee getOrInsertFunction(const std::string &Name,
+  const FunctionType *T)``
 
-  Look up the specified function in the ``Module`` SymbolTable_.  If it does not
-  exist, add an external declaration for the function and return it.
+  Look up the specified function in the ``Module`` SymbolTable_.  If
+  it does not exist, add an external declaration for the function and
+  return it. Note that the function signature already present may not
+  match the requested signature. Thus, in order to enable the common
+  usage of passing the result directly to EmitCall, the return type is
+  a struct of ``{FunctionType *T, Constant *FunctionPtr}``, rather
+  than simply the ``Function*`` with potentially an unexpected
+  signature.
 
 * ``std::string getTypeName(const Type *Ty)``
 
   If there is at least one entry in the SymbolTable_ for the specified Type_,
   return it.  Otherwise return the empty string.
 
 * ``bool addTypeName(const std::string &Name, const Type *Ty)``
 

llvm/examples/BrainF/BrainF.h

protected:
     void readloop(PHINode *phi, BasicBlock *oldbb,
                   BasicBlock *testbb, LLVMContext &Context);
 
     /// Constants during parsing
     int memtotal;
     CompileFlags comflag;
     std::istream *in;
     Module *module;
-    Function *brainf_func;
-    Function *getchar_func;
-    Function *putchar_func;
+    FunctionCallee brainf_func;
+    FunctionCallee getchar_func;
+    FunctionCallee putchar_func;
     Value *ptr_arr;
     Value *ptr_arrmax;
     BasicBlock *endbb;
     BasicBlock *aberrorbb;
 
     /// Variables
     IRBuilder<> *builder;
     Value *curhead;
 };
 
 #endif // BRAINF_H

llvm/examples/BrainF/BrainF.cpp

void BrainF::header(LLVMContext& C) {
   //Function prototypes
 
   //declare void @llvm.memset.p0i8.i32(i8 *, i8, i32, i32, i1)
   Type *Tys[] = { Type::getInt8PtrTy(C), Type::getInt32Ty(C) };
   Function *memset_func = Intrinsic::getDeclaration(module, Intrinsic::memset,
                                                     Tys);
 
   //declare i32 @getchar()
-  getchar_func = cast<Function>(module->
-    getOrInsertFunction("getchar", IntegerType::getInt32Ty(C)));
+  getchar_func =
+      module->getOrInsertFunction("getchar", IntegerType::getInt32Ty(C));
 
   //declare i32 @putchar(i32)
-  putchar_func = cast<Function>(module->
-    getOrInsertFunction("putchar", IntegerType::getInt32Ty(C),
-                        IntegerType::getInt32Ty(C)));
+  putchar_func = module->getOrInsertFunction(
+      "putchar", IntegerType::getInt32Ty(C), IntegerType::getInt32Ty(C));
 
   //Function header
 
   //define void @brainf()
-  brainf_func = cast<Function>(module->
-    getOrInsertFunction("brainf", Type::getVoidTy(C)));
+  brainf_func = module->getOrInsertFunction("brainf", Type::getVoidTy(C));
 
   builder = new IRBuilder<>(BasicBlock::Create(C, label, brainf_func));
 
   //%arr = malloc i8, i32 %d
   ConstantInt *val_mem = ConstantInt::get(C, APInt(32, memtotal));
   BasicBlock* BB = builder->GetInsertBlock();
   Type* IntPtrTy = IntegerType::getInt32Ty(C);
   Type* Int8Ty = IntegerType::getInt8Ty(C);
GlobalVariable *aberrormsg = new GlobalVariable(
       *module,
       msg_0->getType(),
       true,
       GlobalValue::InternalLinkage,
       msg_0,
       "aberrormsg");
 
     //declare i32 @puts(i8 *)
-    Function *puts_func = cast<Function>(module->
-      getOrInsertFunction("puts", IntegerType::getInt32Ty(C),
-                      PointerType::getUnqual(IntegerType::getInt8Ty(C))));
+    FunctionCallee puts_func = module->getOrInsertFunction(
+        "puts", IntegerType::getInt32Ty(C),
+        PointerType::getUnqual(IntegerType::getInt8Ty(C)));
 
     //brainf.aberror:
     aberrorbb = BasicBlock::Create(C, label, brainf_func);
 
     //call i32 @puts(i8 *getelementptr([%d x i8] *@aberrormsg, i32 0, i32 0))
     {
       Constant *zero_32 = Constant::getNullValue(IntegerType::getInt32Ty(C));
 

llvm/examples/BrainF/BrainFDriver.cpp

 ArrayBoundsChecking("abc", cl::desc("Enable array bounds checking"));
 
 static cl::opt<bool>
 JIT("jit", cl::desc("Run program Just-In-Time"));
 
 //Add main function so can be fully compiled
 void addMainFunction(Module *mod) {
   //define i32 @main(i32 %argc, i8 **%argv)
-  Function *main_func = cast<Function>(mod->
-    getOrInsertFunction("main", IntegerType::getInt32Ty(mod->getContext()),
-                        IntegerType::getInt32Ty(mod->getContext()),
-                        PointerType::getUnqual(PointerType::getUnqual(
-                          IntegerType::getInt8Ty(mod->getContext())))));
+  FunctionType *main_func_fty = FunctionType::get(
+      Type::getInt32Ty(mod->getContext()),
+      {Type::getInt32Ty(mod->getContext()),
+       Type::getInt8Ty(mod->getContext())->getPointerTo()->getPointerTo()});
+  Function *main_func =
+      Function::create(main_func_fty, Function::ExternalLinkage, "main", mod);
+
   {
     Function::arg_iterator args = main_func->arg_begin();
     Value *arg_0 = &*args++;
     arg_0->setName("argc");
     Value *arg_1 = &*args++;
     arg_1->setName("argv");
   }
 

llvm/examples/Fibonacci/fibonacci.cpp

 #include <string>
 #include <vector>
 
 using namespace llvm;
 
 static Function *CreateFibFunction(Module *M, LLVMContext &Context) {
   // Create the fib function and insert it into module M. This function is said
   // to return an int and take an int parameter.
+  FunctionType *FibFTy = FunctionType::get(Type::getInt32Ty(Context),
+                                           {Type::getInt32Ty(Context)}, false);
   Function *FibF =
-    cast<Function>(M->getOrInsertFunction("fib", Type::getInt32Ty(Context),
-                                          Type::getInt32Ty(Context)));
+      Function::Create(FibFTy, Function::ExternalLinkage, "fib", M);
 
   // Add a basic block to the function.
   BasicBlock *BB = BasicBlock::Create(Context, "EntryBlock", FibF);
 
   // Get pointers to the constants.
   Value *One = ConstantInt::get(Type::getInt32Ty(Context), 1);
   Value *Two = ConstantInt::get(Type::getInt32Ty(Context), 2);
 

llvm/examples/HowToUseJIT/HowToUseJIT.cpp

int main() {
   LLVMContext Context;
   
   // Create some module to put our function into it.
   std::unique_ptr<Module> Owner = make_unique<Module>("test", Context);
   Module *M = Owner.get();
 
   // Create the add1 function entry and insert this entry into module M.  The
   // function will have a return type of "int" and take an argument of "int".
   Function *Add1F =
-    cast<Function>(M->getOrInsertFunction("add1", Type::getInt32Ty(Context),
-                                          Type::getInt32Ty(Context)));
+      Function::Create(FunctionType::get(Type::getInt32Ty(Context),
+                                         {Type::getInt32Ty(Context)}, false),
+                       Function::ExternalLinkage, "add1", M);
 
   // Add a basic block to the function. As before, it automatically inserts
   // because of the last argument.
   BasicBlock *BB = BasicBlock::Create(Context, "EntryBlock", Add1F);
 
   // Create a basic block builder with default parameters.  The builder will
   // automatically append instructions to the basic block `BB'.
   IRBuilder<> builder(BB);
int main() {
   // Create the return instruction and add it to the basic block
   builder.CreateRet(Add);
 
   // Now, function add1 is ready.
 
   // Now we're going to create function `foo', which returns an int and takes no
   // arguments.
   Function *FooF =
-    cast<Function>(M->getOrInsertFunction("foo", Type::getInt32Ty(Context)));
+      Function::Create(FunctionType::get(Type::getInt32Ty(Context), {}, false),
+                       Function::ExternalLinkage, "foo", M);
 
   // Add a basic block to the FooF function.
   BB = BasicBlock::Create(Context, "EntryBlock", FooF);
 
   // Tell the basic block builder to attach itself to the new basic block
   builder.SetInsertPoint(BB);
 
   // Get pointer to the constant `10'.

llvm/examples/ParallelJIT/ParallelJIT.cpp

 #include <vector>
 #include <pthread.h>
 
 using namespace llvm;
 
 static Function* createAdd1(Module *M) {
   // Create the add1 function entry and insert this entry into module M.  The
   // function will have a return type of "int" and take an argument of "int".
-  // The '0' terminates the list of argument types.
   Function *Add1F =
-    cast<Function>(M->getOrInsertFunction("add1",
-                                          Type::getInt32Ty(M->getContext()),
-                                          Type::getInt32Ty(M->getContext())));
+      Function::Create(FunctionType::get(Type::getInt32Ty(Context),
+                                         {Type::getInt32Ty(Context)}, false),
+                       Function::ExternalLinkage, "add1", M);
 
   // Add a basic block to the function. As before, it automatically inserts
   // because of the last argument.
   BasicBlock *BB = BasicBlock::Create(M->getContext(), "EntryBlock", Add1F);
 
   // Get pointers to the constant `1'.
   Value *One = ConstantInt::get(Type::getInt32Ty(M->getContext()), 1);
 
static Function* createAdd1(Module *M) {
 
   // Now, function add1 is ready.
   return Add1F;
 }
 
 static Function *CreateFibFunction(Module *M) {
   // Create the fib function and insert it into module M.  This function is said
   // to return an int and take an int parameter.
-  Function *FibF = 
-    cast<Function>(M->getOrInsertFunction("fib",
-                                          Type::getInt32Ty(M->getContext()),
-                                          Type::getInt32Ty(M->getContext())));
+  FunctionType *FibFTy = FunctionType::get(Type::getInt32Ty(Context),
+                                           {Type::getInt32Ty(Context)}, false);
+  Function *FibF =
+      Function::Create(FibFTy, Function::ExternalLinkage, "fib", M);
 
   // Add a basic block to the function.
   BasicBlock *BB = BasicBlock::Create(M->getContext(), "EntryBlock", FibF);
 
   // Get pointers to the constants.
   Value *One = ConstantInt::get(Type::getInt32Ty(M->getContext()), 1);
   Value *Two = ConstantInt::get(Type::getInt32Ty(M->getContext()), 2);
 

llvm/include/llvm/CodeGen/IntrinsicLowering.h

 class IntrinsicLowering {
   const DataLayout &DL;
 
   bool Warned;
 
 public:
   explicit IntrinsicLowering(const DataLayout &DL) : DL(DL), Warned(false) {}
 
-  /// Add all of the prototypes that might be needed by an intrinsic lowering
-  /// implementation to be inserted into the module specified.
-  void AddPrototypes(Module &M);
-
   /// Replace a call to the specified intrinsic function.
   /// If an intrinsic function must be implemented by the code generator
   /// (such as va_start), this function should print a message and abort.
   ///
   /// Otherwise, if an intrinsic function call can be lowered, the code to
   /// implement it (often a call to a non-intrinsic function) is inserted
   /// _after_ the call instruction and the call is deleted. The caller must
   /// be capable of handling this kind of change.

llvm/include/llvm/IR/DerivedTypes.h

 Type *Type::getFunctionParamType(unsigned i) const {
   return cast<FunctionType>(this)->getParamType(i);
 }
 
 unsigned Type::getFunctionNumParams() const {
   return cast<FunctionType>(this)->getNumParams();
 }
 
+/// A handy container for a FunctionType+Callee-pointer pair, which can be
+/// passed around as a single entity. This assists in replacing the use of
+/// PointerType::getElementType() to access the function's type, since that's
+/// slated for removal as part of the [opaque pointer types] project.
+class FunctionCallee {
+public:
+  FunctionCallee(FunctionType *FnTy, Value *Callee)
+      : FnTy(FnTy), Callee(Callee) {
+    assert((FnTy == nullptr) == (Callee == nullptr));
+  }
+
+  // Allow implicit conversion from types which have a getFunctionType member
+  // (e.g. Function and InlineAsm).
+  template <typename T,
+            typename U = std::enable_if<&T::getFunctionType != nullptr, void>>
+  FunctionCallee(T *Fn)
+      : FnTy(Fn ? Fn->getFunctionType() : nullptr), Callee(Fn) {}
+  FunctionCallee(std::nullptr_t) : FnTy(nullptr), Callee(nullptr) {}
+  FunctionCallee() : FnTy(nullptr), Callee(nullptr) {}
+
+  FunctionType *getFunctionType() { return FnTy; }
+  Value *getCallee() { return Callee; }
+
+  explicit operator bool() { return Callee; }
+
+private:
+  FunctionType *FnTy;
+  Value *Callee;
+};
+
 /// Common super class of ArrayType, StructType and VectorType.
 class CompositeType : public Type {
 protected:
   explicit CompositeType(LLVMContext &C, TypeID tid) : Type(C, tid) {}
 
 public:
   /// Given an index value into the type, return the type of the element.
   Type *getTypeAtIndex(const Value *V) const;

llvm/include/llvm/IR/IRBuilder.h

public:
   InvokeInst *CreateInvoke(FunctionType *Ty, Value *Callee,
                            BasicBlock *NormalDest, BasicBlock *UnwindDest,
                            ArrayRef<Value *> Args = None,
                            const Twine &Name = "") {
     return Insert(InvokeInst::Create(Ty, Callee, NormalDest, UnwindDest, Args),
                   Name);
   }
 
-  InvokeInst *CreateInvoke(Function *Callee, BasicBlock *NormalDest,
+  InvokeInst *CreateInvoke(FunctionCallee Callee, BasicBlock *NormalDest,
                            BasicBlock *UnwindDest, ArrayRef<Value *> Args,
                            ArrayRef<OperandBundleDef> OpBundles,
                            const Twine &Name = "") {
-    return CreateInvoke(Callee->getFunctionType(), Callee, NormalDest,
-                        UnwindDest, Args, OpBundles, Name);
+    return CreateInvoke(Callee.getFunctionType(), Callee.getCallee(),
+                        NormalDest, UnwindDest, Args, OpBundles, Name);
   }
 
-  InvokeInst *CreateInvoke(Function *Callee, BasicBlock *NormalDest,
+  InvokeInst *CreateInvoke(FunctionCallee Callee, BasicBlock *NormalDest,
                            BasicBlock *UnwindDest,
                            ArrayRef<Value *> Args = None,
                            const Twine &Name = "") {
-    return CreateInvoke(Callee->getFunctionType(), Callee, NormalDest,
-                        UnwindDest, Args, Name);
+    return CreateInvoke(Callee.getFunctionType(), Callee.getCallee(),
+                        NormalDest, UnwindDest, Args, Name);
   }
 
   // Deprecated [opaque pointer types]
   InvokeInst *CreateInvoke(Value *Callee, BasicBlock *NormalDest,
                            BasicBlock *UnwindDest, ArrayRef<Value *> Args,
                            ArrayRef<OperandBundleDef> OpBundles,
                            const Twine &Name = "") {
     return CreateInvoke(
CallInst *CreateCall(FunctionType *FTy, Value *Callee, ArrayRef<Value *> Args,
                        ArrayRef<OperandBundleDef> OpBundles,
                        const Twine &Name = "", MDNode *FPMathTag = nullptr) {
     CallInst *CI = CallInst::Create(FTy, Callee, Args, OpBundles);
     if (isa<FPMathOperator>(CI))
       CI = cast<CallInst>(setFPAttrs(CI, FPMathTag, FMF));
     return Insert(CI, Name);
   }
 
-  CallInst *CreateCall(Function *Callee, ArrayRef<Value *> Args = None,
+  CallInst *CreateCall(FunctionCallee Callee, ArrayRef<Value *> Args = None,
                        const Twine &Name = "", MDNode *FPMathTag = nullptr) {
-    return CreateCall(Callee->getFunctionType(), Callee, Args, Name, FPMathTag);
+    return CreateCall(Callee.getFunctionType(), Callee.getCallee(), Args, Name,
+                      FPMathTag);
   }
 
-  CallInst *CreateCall(Function *Callee, ArrayRef<Value *> Args,
+  CallInst *CreateCall(FunctionCallee Callee, ArrayRef<Value *> Args,
                        ArrayRef<OperandBundleDef> OpBundles,
                        const Twine &Name = "", MDNode *FPMathTag = nullptr) {
-    return CreateCall(Callee->getFunctionType(), Callee, Args, OpBundles, Name,
-                      FPMathTag);
+    return CreateCall(Callee.getFunctionType(), Callee.getCallee(), Args,
+                      OpBundles, Name, FPMathTag);
   }
 
   // Deprecated [opaque pointer types]
   CallInst *CreateCall(Value *Callee, ArrayRef<Value *> Args = None,
                        const Twine &Name = "", MDNode *FPMathTag = nullptr) {
     return CreateCall(
         cast<FunctionType>(Callee->getType()->getPointerElementType()), Callee,
         Args, Name, FPMathTag);

llvm/include/llvm/IR/InstrTypes.h

public:
 
   /// Sets the function called, including updating the function type.
   void setCalledFunction(Value *Fn) {
     setCalledFunction(
         cast<FunctionType>(cast<PointerType>(Fn->getType())->getElementType()),
         Fn);
   }
 
+  /// Sets the function called, including updating the function type.
+  void setCalledFunction(FunctionCallee Fn) {
+    setCalledFunction(Fn.getFunctionType(), Fn.getCallee());
+  }
+
   /// Sets the function called, including updating to the specified function
   /// type.
   void setCalledFunction(FunctionType *FTy, Value *Fn) {
     this->FTy = FTy;
     assert(FTy == cast<FunctionType>(
                       cast<PointerType>(Fn->getType())->getElementType()));
     setCalledOperand(Fn);
   }

llvm/include/llvm/IR/Instructions.h

static CallInst *Create(FunctionType *Ty, Value *Func, ArrayRef<Value *> Args,
     const int NumOperands =
         ComputeNumOperands(Args.size(), CountBundleInputs(Bundles));
     const unsigned DescriptorBytes = Bundles.size() * sizeof(BundleOpInfo);
 
     return new (NumOperands, DescriptorBytes)
         CallInst(Ty, Func, Args, Bundles, NameStr, InsertAtEnd);
   }
 
-  static CallInst *Create(Function *Func, const Twine &NameStr = "",
+  static CallInst *Create(FunctionCallee Func, const Twine &NameStr = "",
                           Instruction *InsertBefore = nullptr) {
-    return Create(Func->getFunctionType(), Func, NameStr, InsertBefore);
+    return Create(Func.getFunctionType(), Func.getCallee(), NameStr,
+                  InsertBefore);
   }
 
-  static CallInst *Create(Function *Func, ArrayRef<Value *> Args,
+  static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args,
+                          ArrayRef<OperandBundleDef> Bundles = None,
                           const Twine &NameStr = "",
                           Instruction *InsertBefore = nullptr) {
-    return Create(Func->getFunctionType(), Func, Args, NameStr, InsertBefore);
+    return Create(Func.getFunctionType(), Func.getCallee(), Args, Bundles,
+                  NameStr, InsertBefore);
+  }
+
+  static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args,
+                          const Twine &NameStr,
+                          Instruction *InsertBefore = nullptr) {
+    return Create(Func.getFunctionType(), Func.getCallee(), Args, NameStr,
+                  InsertBefore);
   }
 
-  static CallInst *Create(Function *Func, const Twine &NameStr,
+  static CallInst *Create(FunctionCallee Func, const Twine &NameStr,
                           BasicBlock *InsertAtEnd) {
-    return Create(Func->getFunctionType(), Func, NameStr, InsertAtEnd);
+    return Create(Func.getFunctionType(), Func.getCallee(), NameStr,
+                  InsertAtEnd);
+  }
+
+  static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args,
+                          const Twine &NameStr, BasicBlock *InsertAtEnd) {
+    return Create(Func.getFunctionType(), Func.getCallee(), Args, NameStr,
+                  InsertAtEnd);
   }
 
-  static CallInst *Create(Function *Func, ArrayRef<Value *> Args,
+  static CallInst *Create(FunctionCallee Func, ArrayRef<Value *> Args,
+                          ArrayRef<OperandBundleDef> Bundles,
                           const Twine &NameStr, BasicBlock *InsertAtEnd) {
-    return Create(Func->getFunctionType(), Func, Args, NameStr, InsertAtEnd);
+    return Create(Func.getFunctionType(), Func.getCallee(), Args, Bundles,
+                  NameStr, InsertAtEnd);
   }
 
   // Deprecated [opaque pointer types]
   static CallInst *Create(Value *Func, const Twine &NameStr = "",
                           Instruction *InsertBefore = nullptr) {
     return Create(cast<FunctionType>(
                       cast<PointerType>(Func->getType())->getElementType()),
                   Func, NameStr, InsertBefore);
int NumOperands =
         ComputeNumOperands(Args.size(), CountBundleInputs(Bundles));
     unsigned DescriptorBytes = Bundles.size() * sizeof(BundleOpInfo);
 
     return new (NumOperands, DescriptorBytes)
         InvokeInst(Ty, Func, IfNormal, IfException, Args, Bundles, NumOperands,
                    NameStr, InsertAtEnd);
   }
 
-  static InvokeInst *Create(Function *Func, BasicBlock *IfNormal,
+  static InvokeInst *Create(FunctionCallee Func, BasicBlock *IfNormal,
                             BasicBlock *IfException, ArrayRef<Value *> Args,
                             const Twine &NameStr,
                             Instruction *InsertBefore = nullptr) {
-    return Create(Func->getFunctionType(), Func, IfNormal, IfException, Args,
-                  None, NameStr, InsertBefore);
+    return Create(Func.getFunctionType(), Func.getCallee(), IfNormal,
+                  IfException, Args, None, NameStr, InsertBefore);
   }
 
-  static InvokeInst *Create(Function *Func, BasicBlock *IfNormal,
+  static InvokeInst *Create(FunctionCallee Func, BasicBlock *IfNormal,
                             BasicBlock *IfException, ArrayRef<Value *> Args,
                             ArrayRef<OperandBundleDef> Bundles = None,
                             const Twine &NameStr = "",
                             Instruction *InsertBefore = nullptr) {
-    return Create(Func->getFunctionType(), Func, IfNormal, IfException, Args,
-                  Bundles, NameStr, InsertBefore);
+    return Create(Func.getFunctionType(), Func.getCallee(), IfNormal,
+                  IfException, Args, Bundles, NameStr, InsertBefore);
   }
 
-  static InvokeInst *Create(Function *Func, BasicBlock *IfNormal,
+  static InvokeInst *Create(FunctionCallee Func, BasicBlock *IfNormal,
                             BasicBlock *IfException, ArrayRef<Value *> Args,
                             const Twine &NameStr, BasicBlock *InsertAtEnd) {
-    return Create(Func->getFunctionType(), Func, IfNormal, IfException, Args,
-                  NameStr, InsertAtEnd);
+    return Create(Func.getFunctionType(), Func.getCallee(), IfNormal,
+                  IfException, Args, NameStr, InsertAtEnd);
   }
 
-  static InvokeInst *Create(Function *Func, BasicBlock *IfNormal,
+  static InvokeInst *Create(FunctionCallee Func, BasicBlock *IfNormal,
                             BasicBlock *IfException, ArrayRef<Value *> Args,
                             ArrayRef<OperandBundleDef> Bundles,
                             const Twine &NameStr, BasicBlock *InsertAtEnd) {
-    return Create(Func->getFunctionType(), Func, IfNormal, IfException, Args,
-                  Bundles, NameStr, InsertAtEnd);
+    return Create(Func.getFunctionType(), Func.getCallee(), IfNormal,
+                  IfException, Args, Bundles, NameStr, InsertAtEnd);
   }
 
   // Deprecated [opaque pointer types]
   static InvokeInst *Create(Value *Func, BasicBlock *IfNormal,
                             BasicBlock *IfException, ArrayRef<Value *> Args,
                             const Twine &NameStr,
                             Instruction *InsertBefore = nullptr) {
     return Create(cast<FunctionType>(

llvm/include/llvm/IR/Module.h

/// @{
   StructType *getTypeByName(StringRef Name) const;
 
   std::vector<StructType *> getIdentifiedStructTypes() const;
 
 /// @}
 /// @name Function Accessors
 /// @{
 
+  /// FIXME: fix function description.
   /// Look up the specified function in the module symbol table. Four
   /// possibilities:
   ///   1. If it does not exist, add a prototype for the function and return it.
   ///   2. If it exists, and has a local linkage, the existing function is
   ///      renamed and a new one is inserted.
   ///   3. Otherwise, if the existing function has the correct prototype, return
   ///      the existing function.
   ///   4. Finally, the function exists but has the wrong prototype: return the
   ///      function with a constantexpr cast to the right prototype.
-  Constant *getOrInsertFunction(StringRef Name, FunctionType *T,
+  FunctionCallee getOrInsertFunction(StringRef Name, FunctionType *T,
                                      AttributeList AttributeList);
 
-  Constant *getOrInsertFunction(StringRef Name, FunctionType *T);
+  FunctionCallee getOrInsertFunction(StringRef Name, FunctionType *T);
 
   /// Look up the specified function in the module symbol table. If it does not
   /// exist, add a prototype for the function and return it. This function
   /// guarantees to return a constant of pointer to the specified function type
   /// or a ConstantExpr BitCast of that type if the named function has a
   /// different type. This version of the method takes a list of
   /// function arguments, which makes it easier for clients to use.
-  template<typename... ArgsTy>
-  Constant *getOrInsertFunction(StringRef Name,
-                                AttributeList AttributeList,
-                                Type *RetTy, ArgsTy... Args)
-  {
+  template <typename... ArgsTy>
+  FunctionCallee getOrInsertFunction(StringRef Name,
+                                     AttributeList AttributeList, Type *RetTy,
+                                     ArgsTy... Args) {
     SmallVector<Type*, sizeof...(ArgsTy)> ArgTys{Args...};
     return getOrInsertFunction(Name,
                                FunctionType::get(RetTy, ArgTys, false),
                                AttributeList);
   }
 
   /// Same as above, but without the attributes.
-  template<typename... ArgsTy>
-  Constant *getOrInsertFunction(StringRef Name, Type *RetTy, ArgsTy... Args) {
+  template <typename... ArgsTy>
+  FunctionCallee getOrInsertFunction(StringRef Name, Type *RetTy,
+                                     ArgsTy... Args) {
     return getOrInsertFunction(Name, AttributeList{}, RetTy, Args...);
   }
 
   // Avoid an incorrect ordering that'd otherwise compile incorrectly.
   template <typename... ArgsTy>
-  Constant *getOrInsertFunction(StringRef Name, AttributeList AttributeList,
-                                FunctionType *Invalid, ArgsTy... Args) = delete;
+  FunctionCallee
+  getOrInsertFunction(StringRef Name, AttributeList AttributeList,
 
   /// Look up the specified function in the module symbol table. If it does not
   /// exist, return null.
   Function *getFunction(StringRef Name) const;
 
 /// @}
 /// @name Global Variable Accessors
 /// @{

llvm/include/llvm/Transforms/Utils/ModuleUtils.h

 #include "llvm/ADT/StringRef.h"
 #include <utility> // for std::pair
 
 namespace llvm {
 
 template <typename T> class ArrayRef;
 class Module;
 class Function;
+class FunctionCallee;
 class GlobalValue;
 class GlobalVariable;
 class Constant;
 class StringRef;
 class Value;
 class Type;
 
 /// Append F to the list of global ctors of module M with the given Priority.
 /// This wraps the function in the appropriate structure and stores it along
 /// side other global constructors. For details see
 /// http://llvm.org/docs/LangRef.html#intg_global_ctors
 void appendToGlobalCtors(Module &M, Function *F, int Priority,
                          Constant *Data = nullptr);
 
 /// Same as appendToGlobalCtors(), but for global dtors.
 void appendToGlobalDtors(Module &M, Function *F, int Priority,
                          Constant *Data = nullptr);
 
-// Validate the result of Module::getOrInsertFunction called for an interface
-// function of given sanitizer. If the instrumented module defines a function
-// with the same name, their prototypes must match, otherwise
-// getOrInsertFunction returns a bitcast.
-Function *checkSanitizerInterfaceFunction(Constant *FuncOrBitcast);
-
-Function *declareSanitizerInitFunction(Module &M, StringRef InitName,
+FunctionCallee declareSanitizerInitFunction(Module &M, StringRef InitName,
                                             ArrayRef<Type *> InitArgTypes);
 
 /// Creates sanitizer constructor function, and calls sanitizer's init
 /// function from it.
 /// \return Returns pair of pointers to constructor, and init functions
 /// respectively.
-std::pair<Function *, Function *> createSanitizerCtorAndInitFunctions(
+std::pair<Function *, FunctionCallee> createSanitizerCtorAndInitFunctions(
     Module &M, StringRef CtorName, StringRef InitName,
     ArrayRef<Type *> InitArgTypes, ArrayRef<Value *> InitArgs,
     StringRef VersionCheckName = StringRef());
 
 /// Creates sanitizer constructor function lazily. If a constructor and init
 /// function already exist, this function returns it. Otherwise it calls \c
 /// createSanitizerCtorAndInitFunctions. The FunctionsCreatedCallback is invoked
 /// in that case, passing the new Ctor and Init function.
 ///
 /// \return Returns pair of pointers to constructor, and init functions
 /// respectively.
-std::pair<Function *, Function *> getOrCreateSanitizerCtorAndInitFunctions(
+std::pair<Function *, FunctionCallee> getOrCreateSanitizerCtorAndInitFunctions(
     Module &M, StringRef CtorName, StringRef InitName,
     ArrayRef<Type *> InitArgTypes, ArrayRef<Value *> InitArgs,
-    function_ref<void(Function *, Function *)> FunctionsCreatedCallback,
+    function_ref<void(Function *, FunctionCallee)> FunctionsCreatedCallback,
     StringRef VersionCheckName = StringRef());
 
 // Creates and returns a sanitizer init function without argument if it doesn't
 // exist, and adds it to the global constructors list. Otherwise it returns the
 // existing function.
 Function *getOrCreateInitFunction(Module &M, StringRef Name);
 
 /// Rename all the anon globals in the module using a hash computed from

llvm/lib/CodeGen/AtomicExpandPass.cpp

bool AtomicExpand::expandAtomicOpToLibcall(
   else
     ResultTy = Type::getVoidTy(Ctx);
 
   // Done with setting up arguments and return types, create the call:
   SmallVector<Type *, 6> ArgTys;
   for (Value *Arg : Args)
     ArgTys.push_back(Arg->getType());
   FunctionType *FnType = FunctionType::get(ResultTy, ArgTys, false);
-  Constant *LibcallFn =
+  FunctionCallee LibcallFn =
       M->getOrInsertFunction(TLI->getLibcallName(RTLibType), FnType, Attr);
   CallInst *Call = Builder.CreateCall(LibcallFn, Args);
   Call->setAttributes(Attr);
   Value *Result = Call;
 
   // And then, extract the results...
   if (ValueOperand && !UseSizedLibcall)
     Builder.CreateLifetimeEnd(AllocaValue_i8, SizeVal64);

llvm/lib/CodeGen/DwarfEHPrepare.cpp

 #define DEBUG_TYPE "dwarfehprepare"
 
 STATISTIC(NumResumesLowered, "Number of resume calls lowered");
 
 namespace {
 
   class DwarfEHPrepare : public FunctionPass {
     // RewindFunction - _Unwind_Resume or the target equivalent.
-    Constant *RewindFunction = nullptr;
+    FunctionCallee RewindFunction = nullptr;
 
     DominatorTree *DT = nullptr;
     const TargetLowering *TLI = nullptr;
 
     bool InsertUnwindResumeCalls(Function &Fn);
     Value *GetExceptionObject(ResumeInst *RI);
     size_t
     pruneUnreachableResumes(Function &Fn,

llvm/lib/CodeGen/IntrinsicLowering.cpp

 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
-template <class ArgIt>
-static void EnsureFunctionExists(Module &M, const char *Name,
-                                 ArgIt ArgBegin, ArgIt ArgEnd,
-                                 Type *RetTy) {
-  // Insert a correctly-typed definition now.
-  std::vector<Type *> ParamTys;
-  for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
-    ParamTys.push_back(I->getType());
-  M.getOrInsertFunction(Name, FunctionType::get(RetTy, ParamTys, false));
-}
-
-static void EnsureFPIntrinsicsExist(Module &M, Function &Fn,
-                                    const char *FName,
-                                    const char *DName, const char *LDName) {
-  // Insert definitions for all the floating point types.
-  switch((int)Fn.arg_begin()->getType()->getTypeID()) {
-  case Type::FloatTyID:
-    EnsureFunctionExists(M, FName, Fn.arg_begin(), Fn.arg_end(),
-                         Type::getFloatTy(M.getContext()));
-    break;
-  case Type::DoubleTyID:
-    EnsureFunctionExists(M, DName, Fn.arg_begin(), Fn.arg_end(),
-                         Type::getDoubleTy(M.getContext()));
-    break;
-  case Type::X86_FP80TyID:
-  case Type::FP128TyID:
-  case Type::PPC_FP128TyID:
-    EnsureFunctionExists(M, LDName, Fn.arg_begin(), Fn.arg_end(),
-                         Fn.arg_begin()->getType());
-    break;
-  }
-}
-
 /// This function is used when we want to lower an intrinsic call to a call of
 /// an external function. This handles hard cases such as when there was already
 /// a prototype for the external function, but that prototype doesn't match the
 /// arguments we expect to pass in.
 template <class ArgIt>
 static CallInst *ReplaceCallWith(const char *NewFn, CallInst *CI,
                                  ArgIt ArgBegin, ArgIt ArgEnd,
                                  Type *RetTy) {
   // If we haven't already looked up this function, check to see if the
   // program already contains a function with this name.
   Module *M = CI->getModule();
   // Get or insert the definition now.
   std::vector<Type *> ParamTys;
   for (ArgIt I = ArgBegin; I != ArgEnd; ++I)
     ParamTys.push_back((*I)->getType());
-  Constant* FCache = M->getOrInsertFunction(NewFn,
-                                  FunctionType::get(RetTy, ParamTys, false));
+  FunctionCallee FCache =
+      M->getOrInsertFunction(NewFn, FunctionType::get(RetTy, ParamTys, false));
 
   IRBuilder<> Builder(CI->getParent(), CI->getIterator());
   SmallVector<Value *, 8> Args(ArgBegin, ArgEnd);
   CallInst *NewCI = Builder.CreateCall(FCache, Args);
   NewCI->setName(CI->getName());
   if (!CI->use_empty())
     CI->replaceAllUsesWith(NewCI);
   return NewCI;
 }
 
 // VisualStudio defines setjmp as _setjmp
 #if defined(_MSC_VER) && defined(setjmp) && \
                          !defined(setjmp_undefined_for_msvc)
 #  pragma push_macro("setjmp")
 #  undef setjmp
 #  define setjmp_undefined_for_msvc
 #endif
 
-void IntrinsicLowering::AddPrototypes(Module &M) {
-  LLVMContext &Context = M.getContext();
-  for (auto &F : M)
-    if (F.isDeclaration() && !F.use_empty())
-      switch (F.getIntrinsicID()) {
-      default: break;
-      case Intrinsic::setjmp:
-        EnsureFunctionExists(M, "setjmp", F.arg_begin(), F.arg_end(),
-                             Type::getInt32Ty(M.getContext()));
-        break;
-      case Intrinsic::longjmp:
-        EnsureFunctionExists(M, "longjmp", F.arg_begin(), F.arg_end(),
-                             Type::getVoidTy(M.getContext()));
-        break;
-      case Intrinsic::siglongjmp:
-        EnsureFunctionExists(M, "abort", F.arg_end(), F.arg_end(),
-                             Type::getVoidTy(M.getContext()));
-        break;
-      case Intrinsic::memcpy:
-        M.getOrInsertFunction("memcpy",
-          Type::getInt8PtrTy(Context),
-                              Type::getInt8PtrTy(Context),
-                              Type::getInt8PtrTy(Context),
-                              DL.getIntPtrType(Context));
-        break;
-      case Intrinsic::memmove:
-        M.getOrInsertFunction("memmove",
-          Type::getInt8PtrTy(Context),
-                              Type::getInt8PtrTy(Context),
-                              Type::getInt8PtrTy(Context),
-                              DL.getIntPtrType(Context));
-        break;
-      case Intrinsic::memset:
-        M.getOrInsertFunction("memset",
-          Type::getInt8PtrTy(Context),
-                              Type::getInt8PtrTy(Context),
-                              Type::getInt32Ty(M.getContext()),
-                              DL.getIntPtrType(Context));
-        break;
-      case Intrinsic::sqrt:
-        EnsureFPIntrinsicsExist(M, F, "sqrtf", "sqrt", "sqrtl");
-        break;
-      case Intrinsic::sin:
-        EnsureFPIntrinsicsExist(M, F, "sinf", "sin", "sinl");
-        break;
-      case Intrinsic::cos:
-        EnsureFPIntrinsicsExist(M, F, "cosf", "cos", "cosl");
-        break;
-      case Intrinsic::pow:
-        EnsureFPIntrinsicsExist(M, F, "powf", "pow", "powl");
-        break;
-      case Intrinsic::log:
-        EnsureFPIntrinsicsExist(M, F, "logf", "log", "logl");
-        break;
-      case Intrinsic::log2:
-        EnsureFPIntrinsicsExist(M, F, "log2f", "log2", "log2l");
-        break;
-      case Intrinsic::log10:
-        EnsureFPIntrinsicsExist(M, F, "log10f", "log10", "log10l");
-        break;
-      case Intrinsic::exp:
-        EnsureFPIntrinsicsExist(M, F, "expf", "exp", "expl");
-        break;
-      case Intrinsic::exp2:
-        EnsureFPIntrinsicsExist(M, F, "exp2f", "exp2", "exp2l");
-        break;
-      }
-}
-
 /// Emit the code to lower bswap of V before the specified instruction IP.
 static Value *LowerBSWAP(LLVMContext &Context, Value *V, Instruction *IP) {
   assert(V->getType()->isIntOrIntVectorTy() && "Can't bswap a non-integer type!");
 
   unsigned BitSize = V->getType()->getScalarSizeInBits();
 
   IRBuilder<> Builder(IP);
 

llvm/lib/CodeGen/MIRParser/MIRParser.cpp

bool MIRParserImpl::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
   } while (In.setCurrentDocument());
 
   return false;
 }
 
 /// Create an empty function with the given name.
 static Function *createDummyFunction(StringRef Name, Module &M) {
   auto &Context = M.getContext();
-  Function *F = cast<Function>(M.getOrInsertFunction(
-      Name, FunctionType::get(Type::getVoidTy(Context), false)));
+  Function *F =
+      Function::Create(FunctionType::get(Type::getVoidTy(Context), false),
+                       Function::ExternalLinkage, Name, M);
   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
   new UnreachableInst(Context, BB);
   return F;
 }
 
 bool MIRParserImpl::parseMachineFunction(Module &M, MachineModuleInfo &MMI) {
   // Parse the yaml.
   yaml::MachineFunction YamlMF;

llvm/lib/CodeGen/MachineOutliner.cpp

MachineOutliner::createOutlinedFunction(Module &M, OutlinedFunction &OF,
   // function.
   std::ostringstream NameStream;
   // FIXME: We should have a better naming scheme. This should be stable,
   // regardless of changes to the outliner's cost model/traversal order.
   NameStream << "OUTLINED_FUNCTION_" << Name;
 
   // Create the function using an IR-level function.
   LLVMContext &C = M.getContext();
-  Function *F = dyn_cast<Function>(
-      M.getOrInsertFunction(NameStream.str(), Type::getVoidTy(C)));
-  assert(F && "Function was null!");
+  Function *F =
+      Function::Create(FunctionType::get(Type::getVoidTy(C), false),
+                       Function::ExternalLinkage, NameStream.str(), M);
 
   // NOTE: If this is linkonceodr, then we can take advantage of linker deduping
   // which gives us better results when we outline from linkonceodr functions.
   F->setLinkage(GlobalValue::InternalLinkage);
   F->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
 
   // FIXME: Set nounwind, so we don't generate eh_frame? Haven't verified it's
   // necessary.

llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp

 static bool lowerObjCCall(Function &F, const char *NewFn,
                           bool setNonLazyBind = false) {
   if (F.use_empty())
     return false;
 
   // If we haven't already looked up this function, check to see if the
   // program already contains a function with this name.
   Module *M = F.getParent();
-  Constant* FCache = M->getOrInsertFunction(NewFn, F.getFunctionType());
+  FunctionCallee FCache = M->getOrInsertFunction(NewFn, F.getFunctionType());
 
-  if (Function* Fn = dyn_cast<Function>(FCache)) {
+  if (Function *Fn = dyn_cast<Function>(FCache.getCallee())) {
     Fn->setLinkage(F.getLinkage());
     if (setNonLazyBind && !Fn->isWeakForLinker()) {
       // If we have Native ARC, set nonlazybind attribute for these APIs for
       // performance.
       Fn->addFnAttr(Attribute::NonLazyBind);
     }
   }
 

llvm/lib/CodeGen/SafeStack.cpp

void SafeStack::checkStackGuard(IRBuilder<> &IRB, Function &F, ReturnInst &RI,
   MDNode *Weights = MDBuilder(F.getContext())
                         .createBranchWeights(SuccessProb.getNumerator(),
                                              FailureProb.getNumerator());
   Instruction *CheckTerm =
       SplitBlockAndInsertIfThen(Cmp, &RI,
                                 /* Unreachable */ true, Weights);
   IRBuilder<> IRBFail(CheckTerm);
   // FIXME: respect -fsanitize-trap / -ftrap-function here?
-  Constant *StackChkFail = F.getParent()->getOrInsertFunction(
-      "__stack_chk_fail", IRB.getVoidTy());
+  FunctionCallee StackChkFail =
+      F.getParent()->getOrInsertFunction("__stack_chk_fail", IRB.getVoidTy());
   IRBFail.CreateCall(StackChkFail, {});
 }
 
 /// We explicitly compute and set the unsafe stack layout for all unsafe
 /// static alloca instructions. We save the unsafe "base pointer" in the
 /// prologue into a local variable and restore it in the epilogue.
 Value *SafeStack::moveStaticAllocasToUnsafeStack(
     IRBuilder<> &IRB, Function &F, ArrayRef<AllocaInst *> StaticAllocas,
if (!StackRestorePoints.empty())
     ++NumUnsafeStackRestorePointsFunctions;
 
   IRBuilder<> IRB(&F.front(), F.begin()->getFirstInsertionPt());
   // Calls must always have a debug location, or else inlining breaks. So
   // we explicitly set a artificial debug location here.
   if (DISubprogram *SP = F.getSubprogram())
     IRB.SetCurrentDebugLocation(DebugLoc::get(SP->getScopeLine(), 0, SP));
   if (SafeStackUsePointerAddress) {
-    Value *Fn = F.getParent()->getOrInsertFunction(
+    FunctionCallee Fn = F.getParent()->getOrInsertFunction(
         "__safestack_pointer_address", StackPtrTy->getPointerTo(0));
     UnsafeStackPtr = IRB.CreateCall(Fn);
   } else {
     UnsafeStackPtr = TL.getSafeStackPointerLocation(IRB);
   }
 
   // Load the current stack pointer (we'll also use it as a base pointer).
   // FIXME: use a dedicated register for it ?

llvm/lib/CodeGen/SjLjEHPrepare.cpp

 STATISTIC(NumInvokes, "Number of invokes replaced");
 STATISTIC(NumSpilled, "Number of registers live across unwind edges");
 
 namespace {
 class SjLjEHPrepare : public FunctionPass {
   Type *doubleUnderDataTy;
   Type *doubleUnderJBufTy;
   Type *FunctionContextTy;
-  Constant *RegisterFn;
-  Constant *UnregisterFn;
-  Constant *BuiltinSetupDispatchFn;
-  Constant *FrameAddrFn;
-  Constant *StackAddrFn;
-  Constant *StackRestoreFn;
-  Constant *LSDAAddrFn;
-  Constant *CallSiteFn;
-  Constant *FuncCtxFn;
+  FunctionCallee RegisterFn;
+  FunctionCallee UnregisterFn;
+  Function *BuiltinSetupDispatchFn;
+  Function *FrameAddrFn;
+  Function *StackAddrFn;
+  Function *StackRestoreFn;
+  Function *LSDAAddrFn;
+  Function *CallSiteFn;
+  Function *FuncCtxFn;
   AllocaInst *FuncCtx;
 
 public:
   static char ID; // Pass identification, replacement for typeid
   explicit SjLjEHPrepare() : FunctionPass(ID) {}
   bool doInitialization(Module &M) override;
   bool runOnFunction(Function &F) override;
 

llvm/lib/CodeGen/StackProtector.cpp

 /// CreateFailBB - Create a basic block to jump to when the stack protector
 /// check fails.
 BasicBlock *StackProtector::CreateFailBB() {
   LLVMContext &Context = F->getContext();
   BasicBlock *FailBB = BasicBlock::Create(Context, "CallStackCheckFailBlk", F);
   IRBuilder<> B(FailBB);
   B.SetCurrentDebugLocation(DebugLoc::get(0, 0, F->getSubprogram()));
   if (Trip.isOSOpenBSD()) {
-    Constant *StackChkFail =
-        M->getOrInsertFunction("__stack_smash_handler",
-                               Type::getVoidTy(Context),
-                               Type::getInt8PtrTy(Context));
+    FunctionCallee StackChkFail = M->getOrInsertFunction(
+        "__stack_smash_handler", Type::getVoidTy(Context),
 
     B.CreateCall(StackChkFail, B.CreateGlobalStringPtr(F->getName(), "SSH"));
   } else {
-    Constant *StackChkFail =
+    FunctionCallee StackChkFail =
         M->getOrInsertFunction("__stack_chk_fail", Type::getVoidTy(Context));
 
     B.CreateCall(StackChkFail, {});
   }
   B.CreateUnreachable();
   return FailBB;
 }
 

llvm/lib/CodeGen/TargetLoweringBase.cpp

 Value *TargetLoweringBase::getSafeStackPointerLocation(IRBuilder<> &IRB) const {
   if (!TM.getTargetTriple().isAndroid())
     return getDefaultSafeStackPointerLocation(IRB, true);
 
   // Android provides a libc function to retrieve the address of the current
   // thread's unsafe stack pointer.
   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
   Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
-  Value *Fn = M->getOrInsertFunction("__safestack_pointer_address",
+  FunctionCallee Fn = M->getOrInsertFunction("__safestack_pointer_address",
                                              StackPtrTy->getPointerTo(0));
   return IRB.CreateCall(Fn);
 }
 
 //===----------------------------------------------------------------------===//
 //  Loop Strength Reduction hooks
 //===----------------------------------------------------------------------===//
 
 /// isLegalAddressingMode - Return true if the addressing mode represented

llvm/lib/CodeGen/WasmEHPrepare.cpp

class WasmEHPrepare : public FunctionPass {
   Value *SelectorField = nullptr;  // selector
 
   Function *ThrowF = nullptr;           // wasm.throw() intrinsic
   Function *CatchF = nullptr;           // wasm.catch.extract() intrinsic
   Function *LPadIndexF = nullptr;       // wasm.landingpad.index() intrinsic
   Function *LSDAF = nullptr;            // wasm.lsda() intrinsic
   Function *GetExnF = nullptr;          // wasm.get.exception() intrinsic
   Function *GetSelectorF = nullptr;     // wasm.get.ehselector() intrinsic
-  Function *CallPersonalityF = nullptr; // _Unwind_CallPersonality() wrapper
+  FunctionCallee CallPersonalityF =
+      nullptr;                          // _Unwind_CallPersonality() wrapper
   Function *ClangCallTermF = nullptr;   // __clang_call_terminate() function
 
   bool prepareEHPads(Function &F);
   bool prepareThrows(Function &F);
 
   void prepareEHPad(BasicBlock *BB, unsigned Index);
   void prepareTerminateCleanupPad(BasicBlock *BB);
 
bool WasmEHPrepare::prepareEHPads(Function &F) {
   // function.
   LSDAF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_lsda);
   // wasm.get.exception() and wasm.get.ehselector() intrinsics. Calls to these
   // are generated in clang.
   GetExnF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_get_exception);
   GetSelectorF = Intrinsic::getDeclaration(&M, Intrinsic::wasm_get_ehselector);
 
   // _Unwind_CallPersonality() wrapper function, which calls the personality
-  CallPersonalityF = cast<Function>(M.getOrInsertFunction(
-      "_Unwind_CallPersonality", IRB.getInt32Ty(), IRB.getInt8PtrTy()));
-  CallPersonalityF->setDoesNotThrow();
+  CallPersonalityF = M.getOrInsertFunction(
+      "_Unwind_CallPersonality", IRB.getInt32Ty(), IRB.getInt8PtrTy());
+  if (Function *F = dyn_cast<Function>(CallPersonalityF.getCallee()))
+    F->setDoesNotThrow();
 
   // __clang_call_terminate() function, which is inserted by clang in case a
   // cleanup throws
   ClangCallTermF = M.getFunction("__clang_call_terminate");
 
   unsigned Index = 0;
   for (auto *BB : CatchPads) {
     auto *CPI = cast<CatchPadInst>(BB->getFirstNonPHI());

llvm/lib/IR/Function.cpp

 /// This defines the "Intrinsic::getAttributes(ID id)" method.
 #define GET_INTRINSIC_ATTRIBUTES
 #include "llvm/IR/IntrinsicImpl.inc"
 #undef GET_INTRINSIC_ATTRIBUTES
 
 Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
   // There can never be multiple globals with the same name of different types,
   // because intrinsics must be a specific type.
-  return
-    cast<Function>(M->getOrInsertFunction(getName(id, Tys),
-                                          getType(M->getContext(), id, Tys)));
+  return cast<Function>(
+      M->getOrInsertFunction(getName(id, Tys),
+                             getType(M->getContext(), id, Tys))
+          .getCallee());
 }
 
 // This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
 #define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
 #include "llvm/IR/IntrinsicImpl.inc"
 #undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
 
 // This defines the "Intrinsic::getIntrinsicForMSBuiltin()" method.

llvm/lib/IR/Instructions.cpp

if (!IsConstantOne(ArraySize)) {
     }
   }
 
   assert(AllocSize->getType() == IntPtrTy && "malloc arg is wrong size");
   // Create the call to Malloc.
   BasicBlock *BB = InsertBefore ? InsertBefore->getParent() : InsertAtEnd;
   Module *M = BB->getParent()->getParent();
   Type *BPTy = Type::getInt8PtrTy(BB->getContext());
-  Value *MallocFunc = MallocF;
+  FunctionCallee MallocFunc = MallocF;
   if (!MallocFunc)
     // prototype malloc as "void *malloc(size_t)"
     MallocFunc = M->getOrInsertFunction("malloc", BPTy, IntPtrTy);
   PointerType *AllocPtrType = PointerType::getUnqual(AllocTy);
   CallInst *MCall = nullptr;
   Instruction *Result = nullptr;
   if (InsertBefore) {
     MCall = CallInst::Create(MallocFunc, AllocSize, OpB, "malloccall",
                              InsertBefore);
     Result = MCall;
     if (Result->getType() != AllocPtrType)
       // Create a cast instruction to convert to the right type...
       Result = new BitCastInst(MCall, AllocPtrType, Name, InsertBefore);
   } else {
     MCall = CallInst::Create(MallocFunc, AllocSize, OpB, "malloccall");
     Result = MCall;
     if (Result->getType() != AllocPtrType) {
       InsertAtEnd->getInstList().push_back(MCall);
       // Create a cast instruction to convert to the right type...
       Result = new BitCastInst(MCall, AllocPtrType, Name);
     }
   }
   MCall->setTailCall();
-  if (Function *F = dyn_cast<Function>(MallocFunc)) {
+  if (Function *F = dyn_cast<Function>(MallocFunc.getCallee())) {
     MCall->setCallingConv(F->getCallingConv());
     if (!F->returnDoesNotAlias())
       F->setReturnDoesNotAlias();
   }
   assert(!MCall->getType()->isVoidTy() && "Malloc has void return type");
 
   return Result;
 }
assert(Source->getType()->isPointerTy() &&
          "Can not free something of nonpointer type!");
 
   BasicBlock *BB = InsertBefore ? InsertBefore->getParent() : InsertAtEnd;
   Module *M = BB->getParent()->getParent();
 
   Type *VoidTy = Type::getVoidTy(M->getContext());
   Type *IntPtrTy = Type::getInt8PtrTy(M->getContext());
   // prototype free as "void free(void*)"
-  Value *FreeFunc = M->getOrInsertFunction("free", VoidTy, IntPtrTy);
+  FunctionCallee FreeFunc = M->getOrInsertFunction("free", VoidTy, IntPtrTy);
   CallInst *Result = nullptr;
   Value *PtrCast = Source;
   if (InsertBefore) {
     if (Source->getType() != IntPtrTy)
       PtrCast = new BitCastInst(Source, IntPtrTy, "", InsertBefore);
     Result = CallInst::Create(FreeFunc, PtrCast, Bundles, "", InsertBefore);
   } else {
     if (Source->getType() != IntPtrTy)
       PtrCast = new BitCastInst(Source, IntPtrTy, "", InsertAtEnd);
     Result = CallInst::Create(FreeFunc, PtrCast, Bundles, "");
   }
   Result->setTailCall();
-  if (Function *F = dyn_cast<Function>(FreeFunc))
+  if (Function *F = dyn_cast<Function>(FreeFunc.getCallee()))
     Result->setCallingConv(F->getCallingConv());
 
   return Result;
 }
 
 /// CreateFree - Generate the IR for a call to the builtin free function.
 Instruction *CallInst::CreateFree(Value *Source, Instruction *InsertBefore) {
   return createFree(Source, None, InsertBefore, nullptr);

llvm/lib/IR/Module.cpp

 // Methods for easy access to the functions in the module.
 //
 
 // getOrInsertFunction - Look up the specified function in the module symbol
 // table.  If it does not exist, add a prototype for the function and return
 // it.  This is nice because it allows most passes to get away with not handling
 // the symbol table directly for this common task.
 //
-Constant *Module::getOrInsertFunction(StringRef Name, FunctionType *Ty,
+FunctionCallee Module::getOrInsertFunction(StringRef Name, FunctionType *Ty,
                                            AttributeList AttributeList) {
   // See if we have a definition for the specified function already.
   GlobalValue *F = getNamedValue(Name);
   if (!F) {
     // Nope, add it
     Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage,
                                      DL.getProgramAddressSpace(), Name);
     if (!New->isIntrinsic())       // Intrinsics get attrs set on construction
       New->setAttributes(AttributeList);
     FunctionList.push_back(New);
-    return New;                    // Return the new prototype.
+    return {Ty, New}; // Return the new prototype.
   }
 
   // If the function exists but has the wrong type, return a bitcast to the
   // right type.
   auto *PTy = PointerType::get(Ty, F->getAddressSpace());
   if (F->getType() != PTy)
-    return ConstantExpr::getBitCast(F, PTy);
+    return {Ty, ConstantExpr::getBitCast(F, PTy)};
 
   // Otherwise, we just found the existing function or a prototype.
-  return F;
+  return {Ty, F};
 }
 
-Constant *Module::getOrInsertFunction(StringRef Name,
-                                      FunctionType *Ty) {
+FunctionCallee Module::getOrInsertFunction(StringRef Name, FunctionType *Ty) {
   return getOrInsertFunction(Name, Ty, AttributeList());
 }
 
 // getFunction - Look up the specified function in the module symbol table.
 // If it does not exist, return null.
 //
 Function *Module::getFunction(StringRef Name) const {
   return dyn_cast_or_null<Function>(getNamedValue(Name));

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

 void AArch64TargetLowering::insertSSPDeclarations(Module &M) const {
   // MSVC CRT provides functionalities for stack protection.
   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment()) {
     // MSVC CRT has a global variable holding security cookie.
     M.getOrInsertGlobal("__security_cookie",
                         Type::getInt8PtrTy(M.getContext()));
 
     // MSVC CRT has a function to validate security cookie.
-    auto *SecurityCheckCookie = cast<Function>(
-        M.getOrInsertFunction("__security_check_cookie",
-                              Type::getVoidTy(M.getContext()),
-                              Type::getInt8PtrTy(M.getContext())));
-    SecurityCheckCookie->setCallingConv(CallingConv::Win64);
-    SecurityCheckCookie->addAttribute(1, Attribute::AttrKind::InReg);
+    FunctionCallee SecurityCheckCookie = M.getOrInsertFunction(
+        "__security_check_cookie", Type::getVoidTy(M.getContext()),
+        Type::getInt8PtrTy(M.getContext()));
+    if (Function *F = dyn_cast<Function>(SecurityCheckCookie.getCallee())) {
+      F->setCallingConv(CallingConv::Win64);
+      F->addAttribute(1, Attribute::AttrKind::InReg);
+    }
     return;
   }
   TargetLowering::insertSSPDeclarations(M);
 }
 
 Value *AArch64TargetLowering::getSDagStackGuard(const Module &M) const {
   // MSVC CRT has a global variable holding security cookie.
   if (Subtarget->getTargetTriple().isWindowsMSVCEnvironment())

llvm/lib/Target/AMDGPU/AMDGPULibCalls.cpp

private:
 
   // -fuse-native.
   bool AllNative = false;
 
   bool useNativeFunc(const StringRef F) const;
 
   // Return a pointer (pointer expr) to the function if function defintion with
   // "FuncName" exists. It may create a new function prototype in pre-link mode.
-  Constant *getFunction(Module *M, const FuncInfo& fInfo);
+  FunctionCallee getFunction(Module *M, const FuncInfo &fInfo);
 
   // Replace a normal function with its native version.
   bool replaceWithNative(CallInst *CI, const FuncInfo &FInfo);
 
   bool parseFunctionName(const StringRef& FMangledName,
                          FuncInfo *FInfo=nullptr /*out*/);
 
   bool TDOFold(CallInst *CI, const FuncInfo &FInfo);
private:
   // __read_pipe/__write_pipe
   bool fold_read_write_pipe(CallInst *CI, IRBuilder<> &B, FuncInfo &FInfo);
 
   // Get insertion point at entry.
   BasicBlock::iterator getEntryIns(CallInst * UI);
   // Insert an Alloc instruction.
   AllocaInst* insertAlloca(CallInst * UI, IRBuilder<> &B, const char *prefix);
   // Get a scalar native builtin signle argument FP function
-  Constant* getNativeFunction(Module* M, const FuncInfo &FInfo);
+  FunctionCallee getNativeFunction(Module *M, const FuncInfo &FInfo);
 
 protected:
   CallInst *CI;
 
   bool isUnsafeMath(const CallInst *CI) const;
 
   void replaceCall(Value *With) {
     CI->replaceAllUsesWith(With);

 INITIALIZE_PASS_END(AMDGPUSimplifyLibCalls, "amdgpu-simplifylib",
                     "Simplify well-known AMD library calls", false, false)
 
 INITIALIZE_PASS(AMDGPUUseNativeCalls, "amdgpu-usenative",
                 "Replace builtin math calls with that native versions.",
                 false, false)
 
 template <typename IRB>
-static CallInst *CreateCallEx(IRB &B, Value *Callee, Value *Arg,
+static CallInst *CreateCallEx(IRB &B, FunctionCallee Callee, Value *Arg,
                               const Twine &Name = "") {
   CallInst *R = B.CreateCall(Callee, Arg, Name);
-  if (Function* F = dyn_cast<Function>(Callee))
+  if (Function *F = dyn_cast<Function>(Callee.getCallee()))
     R->setCallingConv(F->getCallingConv());
   return R;
 }
 
 template <typename IRB>
-static CallInst *CreateCallEx2(IRB &B, Value *Callee, Value *Arg1, Value *Arg2,
-                               const Twine &Name = "") {
+static CallInst *CreateCallEx2(IRB &B, FunctionCallee Callee, Value *Arg1,
+                               Value *Arg2, const Twine &Name = "") {
   CallInst *R = B.CreateCall(Callee, {Arg1, Arg2}, Name);
-  if (Function* F = dyn_cast<Function>(Callee))
+  if (Function *F = dyn_cast<Function>(Callee.getCallee()))
     R->setCallingConv(F->getCallingConv());
   return R;
 }
 
 //  Data structures for table-driven optimizations.
 //  FuncTbl works for both f32 and f64 functions with 1 input argument
 
 struct TableEntry {

 static inline int getVecSize(const AMDGPULibFunc& FInfo) {
   return FInfo.getLeads()[0].VectorSize;
 }
 
 static inline AMDGPULibFunc::EType getArgType(const AMDGPULibFunc& FInfo) {
   return (AMDGPULibFunc::EType)FInfo.getLeads()[0].ArgType;
 }
 
-Constant *AMDGPULibCalls::getFunction(Module *M, const FuncInfo& fInfo) {
+FunctionCallee AMDGPULibCalls::getFunction(Module *M, const FuncInfo &fInfo) {
   // If we are doing PreLinkOpt, the function is external. So it is safe to
   // use getOrInsertFunction() at this stage.
 
   return EnablePreLink ? AMDGPULibFunc::getOrInsertFunction(M, fInfo)
                        : AMDGPULibFunc::getFunction(M, fInfo);
 }
 
 bool AMDGPULibCalls::parseFunctionName(const StringRef& FMangledName,
if (native_sin && native_cos) {
     Value *opr0 = aCI->getArgOperand(0);
 
     AMDGPULibFunc nf;
     nf.getLeads()[0].ArgType = FInfo.getLeads()[0].ArgType;
     nf.getLeads()[0].VectorSize = FInfo.getLeads()[0].VectorSize;
 
     nf.setPrefix(AMDGPULibFunc::NATIVE);
     nf.setId(AMDGPULibFunc::EI_SIN);
-    Constant *sinExpr = getFunction(M, nf);
+    FunctionCallee sinExpr = getFunction(M, nf);
 
     nf.setPrefix(AMDGPULibFunc::NATIVE);
     nf.setId(AMDGPULibFunc::EI_COS);
-    Constant *cosExpr = getFunction(M, nf);
+    FunctionCallee cosExpr = getFunction(M, nf);
     if (sinExpr && cosExpr) {
       Value *sinval = CallInst::Create(sinExpr, opr0, "splitsin", aCI);
       Value *cosval = CallInst::Create(cosExpr, opr0, "splitcos", aCI);
       new StoreInst(cosval, aCI->getArgOperand(1), aCI);
 
       DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI
                                           << " with native version of sin/cos");
 
if (!parseFunctionName(Callee->getName(), &FInfo) || !FInfo.isMangled() ||
       !(AllNative || useNativeFunc(FInfo.getName()))) {
     return false;
   }
 
   if (FInfo.getId() == AMDGPULibFunc::EI_SINCOS)
     return sincosUseNative(aCI, FInfo);
 
   FInfo.setPrefix(AMDGPULibFunc::NATIVE);
-  Constant *F = getFunction(aCI->getModule(), FInfo);
+  FunctionCallee F = getFunction(aCI->getModule(), FInfo);
   if (!F)
     return false;
 
   aCI->setCalledFunction(F);
   DEBUG_WITH_TYPE("usenative", dbgs() << "<useNative> replace " << *aCI
                                       << " with native version");
   return true;
 }
bool AMDGPULibCalls::fold_read_write_pipe(CallInst *CI, IRBuilder<> &B,
   for (unsigned I = 0; I != PtrArgLoc; ++I)
     ArgTys.push_back(CI->getArgOperand(I)->getType());
   ArgTys.push_back(PtrTy);
 
   Name = Name + "_" + std::to_string(Size);
   auto *FTy = FunctionType::get(Callee->getReturnType(),
                                 ArrayRef<Type *>(ArgTys), false);
   AMDGPULibFunc NewLibFunc(Name, FTy);
-  auto *F = AMDGPULibFunc::getOrInsertFunction(M, NewLibFunc);
+  FunctionCallee F = AMDGPULibFunc::getOrInsertFunction(M, NewLibFunc);
   if (!F)
     return false;
 
   auto *BCast = B.CreatePointerCast(PtrArg, PtrTy);
   SmallVector<Value *, 6> Args;
   for (unsigned I = 0; I != PtrArgLoc; ++I)
     Args.push_back(CI->getArgOperand(I));
   Args.push_back(BCast);
bool AMDGPULibCalls::replaceWithNative(CallInst *CI, const FuncInfo &FInfo) {
   Module *M = CI->getModule();
   if (getArgType(FInfo) != AMDGPULibFunc::F32 ||
       FInfo.getPrefix() != AMDGPULibFunc::NOPFX ||
       !HasNative(FInfo.getId()))
     return false;
 
   AMDGPULibFunc nf = FInfo;
   nf.setPrefix(AMDGPULibFunc::NATIVE);
-  if (Constant *FPExpr = getFunction(M, nf)) {
+  if (FunctionCallee FPExpr = getFunction(M, nf)) {
     LLVM_DEBUG(dbgs() << "AMDIC: " << *CI << " ---> ");
 
     CI->setCalledFunction(FPExpr);
 
     LLVM_DEBUG(dbgs() << *CI << '\n');
 
     return true;
   }
if ((CF && CF->isExactlyValue(-1.0)) || (CINT && ci_opr1 == -1)) {
     replaceCall(nval);
     return true;
   }
 
   Module *M = CI->getModule();
   if (CF && (CF->isExactlyValue(0.5) || CF->isExactlyValue(-0.5))) {
     // pow[r](x, [-]0.5) = sqrt(x)
     bool issqrt = CF->isExactlyValue(0.5);
-    if (Constant *FPExpr = getFunction(M,
-        AMDGPULibFunc(issqrt ? AMDGPULibFunc::EI_SQRT
-                             : AMDGPULibFunc::EI_RSQRT, FInfo))) {
+    if (FunctionCallee FPExpr =
+            getFunction(M, AMDGPULibFunc(issqrt ? AMDGPULibFunc::EI_SQRT
+                                                : AMDGPULibFunc::EI_RSQRT,
+                                         FInfo))) {
       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
                         << FInfo.getName().c_str() << "(" << *opr0 << ")\n");
       Value *nval = CreateCallEx(B,FPExpr, opr0, issqrt ? "__pow2sqrt"
                                                         : "__pow2rsqrt");
       replaceCall(nval);
       return true;
     }
   }
LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
                       << ((ci_opr1 < 0) ? "1/prod(" : "prod(") << *opr0
                       << ")\n");
     replaceCall(nval);
     return true;
   }
 
   // powr ---> exp2(y * log2(x))
   // pown/pow ---> powr(fabs(x), y) | (x & ((int)y << 31))
-  Constant *ExpExpr = getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_EXP2,
-                                                   FInfo));
+  FunctionCallee ExpExpr =
+      getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_EXP2, FInfo));
   if (!ExpExpr)
     return false;
 
   bool needlog = false;
   bool needabs = false;
   bool needcopysign = false;
   Constant *cnval = nullptr;
   if (getVecSize(FInfo) == 1) {
if (getVecSize(FInfo) == 1) {
         }
       } else
         return false;
     }
   }
 
   Value *nval;
   if (needabs) {
-    Constant *AbsExpr = getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_FABS,
-                                                     FInfo));
+    FunctionCallee AbsExpr =
+        getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_FABS, FInfo));
     if (!AbsExpr)
       return false;
     nval = CreateCallEx(B, AbsExpr, opr0, "__fabs");
   } else {
     nval = cnval ? cnval : opr0;
   }
   if (needlog) {
-    Constant *LogExpr = getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_LOG2,
-                                                     FInfo));
+    FunctionCallee LogExpr =
+        getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_LOG2, FInfo));
     if (!LogExpr)
       return false;
     nval = CreateCallEx(B,LogExpr, nval, "__log2");
   }
 
   if (FInfo.getId() == AMDGPULibFunc::EI_POWN) {
     // convert int(32) to fp(f32 or f64)
     opr1 = B.CreateSIToFP(opr1, nval->getType(), "pownI2F");
if (ci_opr1 == 1) {  // rootn(x, 1) = x
     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> " << *opr0 << "\n");
     replaceCall(opr0);
     return true;
   }
   if (ci_opr1 == 2) {  // rootn(x, 2) = sqrt(x)
     std::vector<const Type*> ParamsTys;
     ParamsTys.push_back(opr0->getType());
     Module *M = CI->getModule();
-    if (Constant *FPExpr = getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT,
-                                                        FInfo))) {
+    if (FunctionCallee FPExpr =
+            getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) {
       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> sqrt(" << *opr0 << ")\n");
       Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2sqrt");
       replaceCall(nval);
       return true;
     }
   } else if (ci_opr1 == 3) { // rootn(x, 3) = cbrt(x)
     Module *M = CI->getModule();
-    if (Constant *FPExpr = getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_CBRT,
-                                                        FInfo))) {
+    if (FunctionCallee FPExpr =
+            getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_CBRT, FInfo))) {
       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> cbrt(" << *opr0 << ")\n");
       Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2cbrt");
       replaceCall(nval);
       return true;
     }
   } else if (ci_opr1 == -1) { // rootn(x, -1) = 1.0/x
     LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> 1.0 / " << *opr0 << "\n");
     Value *nval = B.CreateFDiv(ConstantFP::get(opr0->getType(), 1.0),
                                opr0,
                                "__rootn2div");
     replaceCall(nval);
     return true;
   } else if (ci_opr1 == -2) {  // rootn(x, -2) = rsqrt(x)
     std::vector<const Type*> ParamsTys;
     ParamsTys.push_back(opr0->getType());
     Module *M = CI->getModule();
-    if (Constant *FPExpr = getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_RSQRT,
-                                                        FInfo))) {
+    if (FunctionCallee FPExpr =
+            getFunction(M, AMDGPULibFunc(AMDGPULibFunc::EI_RSQRT, FInfo))) {
       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> rsqrt(" << *opr0
                         << ")\n");
       Value *nval = CreateCallEx(B,FPExpr, opr0, "__rootn2rsqrt");
       replaceCall(nval);
       return true;
     }
   }
   return false;
if (CF->isZero()) {
       return true;
     }
   }
 
   return false;
 }
 
 // Get a scalar native builtin signle argument FP function
-Constant* AMDGPULibCalls::getNativeFunction(Module* M, const FuncInfo& FInfo) {
+FunctionCallee AMDGPULibCalls::getNativeFunction(Module *M,
+                                                 const FuncInfo &FInfo) {
   if (getArgType(FInfo) == AMDGPULibFunc::F64 || !HasNative(FInfo.getId()))
     return nullptr;
   FuncInfo nf = FInfo;
   nf.setPrefix(AMDGPULibFunc::NATIVE);
   return getFunction(M, nf);
 }
 
 // fold sqrt -> native_sqrt (x)
 bool AMDGPULibCalls::fold_sqrt(CallInst *CI, IRBuilder<> &B,
                                const FuncInfo &FInfo) {
   if (getArgType(FInfo) == AMDGPULibFunc::F32 && (getVecSize(FInfo) == 1) &&
       (FInfo.getPrefix() != AMDGPULibFunc::NATIVE)) {
-    if (Constant *FPExpr = getNativeFunction(
+    if (FunctionCallee FPExpr = getNativeFunction(
             CI->getModule(), AMDGPULibFunc(AMDGPULibFunc::EI_SQRT, FInfo))) {
       Value *opr0 = CI->getArgOperand(0);
       LLVM_DEBUG(errs() << "AMDIC: " << *CI << " ---> "
                         << "sqrt(" << *opr0 << ")\n");
       Value *nval = CreateCallEx(B,FPExpr, opr0, "__sqrt");
       replaceCall(nval);
       return true;
     }
   }
bool AMDGPULibCalls::fold_sincos(CallInst *CI, IRBuilder<> &B,
   if (!UI) return false;
 
   // Merge the sin and cos.
 
   // for OpenCL 2.0 we have only generic implementation of sincos
   // function.
   AMDGPULibFunc nf(AMDGPULibFunc::EI_SINCOS, fInfo);
   nf.getLeads()[0].PtrKind = AMDGPULibFunc::getEPtrKindFromAddrSpace(AMDGPUAS::FLAT_ADDRESS);
-  Function *Fsincos = dyn_cast_or_null<Function>(getFunction(M, nf));
+  FunctionCallee Fsincos = getFunction(M, nf);
   if (!Fsincos) return false;
 
   BasicBlock::iterator ItOld = B.GetInsertPoint();
   AllocaInst *Alloc = insertAlloca(UI, B, "__sincos_");
   B.SetInsertPoint(UI);
 
   Value *P = Alloc;
-  Type *PTy = Fsincos->getFunctionType()->getParamType(1);
+  Type *PTy = Fsincos.getFunctionType()->getParamType(1);
   // The allocaInst allocates the memory in private address space. This need
   // to be bitcasted to point to the address space of cos pointer type.
   // In OpenCL 2.0 this is generic, while in 1.2 that is private.
   if (PTy->getPointerAddressSpace() != AMDGPUAS::PRIVATE_ADDRESS)
     P = B.CreateAddrSpaceCast(Alloc, PTy);
   CallInst *Call = CreateCallEx2(B, Fsincos, UI->getArgOperand(0), P);
 
   LLVM_DEBUG(errs() << "AMDIC: fold_sincos (" << *CI << ", " << *UI << ") with "

llvm/lib/Target/AMDGPU/AMDGPULibFunc.h

public:
   void setName(StringRef N) { Impl->setName(N); }
   void setPrefix(ENamePrefix PFX) { Impl->setPrefix(PFX); }
 
   FunctionType *getFunctionType(Module &M) const {
     return Impl->getFunctionType(M);
   }
   static Function *getFunction(llvm::Module *M, const AMDGPULibFunc &fInfo);
 
-  static Function *getOrInsertFunction(llvm::Module *M,
+  static FunctionCallee getOrInsertFunction(llvm::Module *M,
                                             const AMDGPULibFunc &fInfo);
   static bool parse(StringRef MangledName, AMDGPULibFunc &Ptr);
 
 private:
   /// Initialize as a mangled library function.
   void initMangled();
   std::unique_ptr<AMDGPULibFuncImpl> Impl;
 };
 

llvm/lib/Target/AMDGPU/AMDGPULibFunc.cpp

Function *AMDGPULibFunc::getFunction(Module *M, const AMDGPULibFunc &fInfo) {
   if (F && !F->isDeclaration()
         && !F->isVarArg()
         && F->arg_size() == fInfo.getNumArgs()) {
     return F;
   }
   return nullptr;
 }
 
-Function *AMDGPULibFunc::getOrInsertFunction(Module *M,
+FunctionCallee AMDGPULibFunc::getOrInsertFunction(Module *M,
                                                   const AMDGPULibFunc &fInfo) {
   std::string const FuncName = fInfo.mangle();
   Function *F = dyn_cast_or_null<Function>(
     M->getValueSymbolTable().lookup(FuncName));
 
   // check formal with actual types conformance
   if (F && !F->isDeclaration()
         && !F->isVarArg()
         && F->arg_size() == fInfo.getNumArgs()) {
for (FunctionType::param_iterator
        PI != PE; ++PI) {
     const Type* argTy = static_cast<const Type*>(*PI);
     if (argTy->isPointerTy()) {
       hasPtr = true;
       break;
     }
   }
 
-  Constant *C = nullptr;
+  FunctionCallee C;
   if (hasPtr) {
     // Do not set extra attributes for functions with pointer arguments.
     C = M->getOrInsertFunction(FuncName, FuncTy);
   } else {
     AttributeList Attr;
     LLVMContext &Ctx = M->getContext();
     Attr = Attr.addAttribute(Ctx, AttributeList::FunctionIndex,
                              Attribute::ReadOnly);
     Attr = Attr.addAttribute(Ctx, AttributeList::FunctionIndex,
                              Attribute::NoUnwind);
     C = M->getOrInsertFunction(FuncName, FuncTy, Attr);
   }
 
-  return cast<Function>(C);
+  return C;
 }
 
 bool UnmangledFuncInfo::lookup(StringRef Name, ID &Id) {
   auto Loc = Map.find(Name);
   if (Loc != Map.end()) {
     Id = toFuncId(Loc->second);
     return true;
   }

llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp

if (RuntimeCheck) {
     CondBuilder.CreateBr(ExitB);
     CondBuilder.SetInsertPoint(MemmoveB->getTerminator());
 
     if (DestVolatile) {
       Type *Int32Ty = Type::getInt32Ty(Ctx);
       Type *Int32PtrTy = Type::getInt32PtrTy(Ctx);
       Type *VoidTy = Type::getVoidTy(Ctx);
       Module *M = Func->getParent();
-      Constant *CF = M->getOrInsertFunction(HexagonVolatileMemcpyName, VoidTy,
-                                            Int32PtrTy, Int32PtrTy, Int32Ty);
-      Function *Fn = cast<Function>(CF);
-      Fn->setLinkage(Function::ExternalLinkage);
+      FunctionCallee Fn = M->getOrInsertFunction(
+          HexagonVolatileMemcpyName, VoidTy, Int32PtrTy, Int32PtrTy, Int32Ty);
 
       const SCEV *OneS = SE->getConstant(Int32Ty, 1);
       const SCEV *BECount32 = SE->getTruncateOrZeroExtend(BECount, Int32Ty);
       const SCEV *NumWordsS = SE->getAddExpr(BECount32, OneS, SCEV::FlagNUW);
       Value *NumWords = Expander.expandCodeFor(NumWordsS, Int32Ty,
                                                MemmoveB->getTerminator());
       if (Instruction *In = dyn_cast<Instruction>(NumWords))
         if (Value *Simp = SimplifyInstruction(In, {*DL, TLI, DT}))

llvm/lib/Target/Mips/Mips16HardFloat.cpp

for (auto &I: BB) {
         // functions will take place.
         //
         A = A.addAttribute(C, AttributeList::FunctionIndex,
                            "__Mips16RetHelper");
         A = A.addAttribute(C, AttributeList::FunctionIndex,
                            Attribute::ReadNone);
         A = A.addAttribute(C, AttributeList::FunctionIndex,
                            Attribute::NoInline);
-        Value *F = (M->getOrInsertFunction(Name, A, MyVoid, T));
+        FunctionCallee F = (M->getOrInsertFunction(Name, A, MyVoid, T));
         CallInst::Create(F, Params, "", &I);
       } else if (const CallInst *CI = dyn_cast<CallInst>(&I)) {
         FunctionType *FT = CI->getFunctionType();
         Function *F_ =  CI->getCalledFunction();
         if (needsFPReturnHelper(*FT) &&
             !(F_ && isIntrinsicInline(F_))) {
           Modified=true;
           F.addFnAttr("saveS2");

llvm/lib/Target/WebAssembly/WebAssemblyLowerGlobalDtors.cpp

bool LowerGlobalDtors::runOnModule(Module &M) {
   // extern "C" int __cxa_atexit(void (*f)(void *), void *p, void *d);
   LLVMContext &C = M.getContext();
   PointerType *VoidStar = Type::getInt8PtrTy(C);
   Type *AtExitFuncArgs[] = {VoidStar};
   FunctionType *AtExitFuncTy =
       FunctionType::get(Type::getVoidTy(C), AtExitFuncArgs,
                         /*isVarArg=*/false);
 
-  Type *AtExitArgs[] = {PointerType::get(AtExitFuncTy, 0), VoidStar, VoidStar};
-  FunctionType *AtExitTy = FunctionType::get(Type::getInt32Ty(C), AtExitArgs,
-                                             /*isVarArg=*/false);
-  Constant *AtExit = M.getOrInsertFunction("__cxa_atexit", AtExitTy);
+  FunctionCallee AtExit = M.getOrInsertFunction(
+      "__cxa_atexit",
+      FunctionType::get(Type::getInt32Ty(C),
+                        {PointerType::get(AtExitFuncTy, 0), VoidStar, VoidStar},
+                        /*isVarArg=*/false));
 
   // Declare __dso_local.
   Constant *DsoHandle = M.getNamedValue("__dso_handle");
   if (!DsoHandle) {
     Type *DsoHandleTy = Type::getInt8Ty(C);
     GlobalVariable *Handle = new GlobalVariable(
         M, DsoHandleTy, /*isConstant=*/true,
         GlobalVariable::ExternalWeakLinkage, nullptr, "__dso_handle");

llvm/lib/Target/X86/X86ISelLowering.cpp

void X86TargetLowering::insertSSPDeclarations(Module &M) const {
   // MSVC CRT provides functionalities for stack protection.
   if (Subtarget.getTargetTriple().isWindowsMSVCEnvironment() ||
       Subtarget.getTargetTriple().isWindowsItaniumEnvironment()) {
     // MSVC CRT has a global variable holding security cookie.
     M.getOrInsertGlobal("__security_cookie",
                         Type::getInt8PtrTy(M.getContext()));
 
     // MSVC CRT has a function to validate security cookie.
-    auto *SecurityCheckCookie = cast<Function>(
-        M.getOrInsertFunction("__security_check_cookie",
-                              Type::getVoidTy(M.getContext()),
-                              Type::getInt8PtrTy(M.getContext())));
-    SecurityCheckCookie->setCallingConv(CallingConv::X86_FastCall);
-    SecurityCheckCookie->addAttribute(1, Attribute::AttrKind::InReg);
+    FunctionCallee SecurityCheckCookie = M.getOrInsertFunction(
+        "__security_check_cookie", Type::getVoidTy(M.getContext()),
+        Type::getInt8PtrTy(M.getContext()));
+    if (Function *F = dyn_cast<Function>(SecurityCheckCookie.getCallee())) {
+      F->setCallingConv(CallingConv::X86_FastCall);
+      F->addAttribute(1, Attribute::AttrKind::InReg);
+    }
     return;
   }
   // glibc, bionic, and Fuchsia have a special slot for the stack guard.
   if (hasStackGuardSlotTLS(Subtarget.getTargetTriple()))
     return;
   TargetLowering::insertSSPDeclarations(M);
 }
 

llvm/lib/Target/X86/X86WinEHState.cpp

private:
   Type *getSEHRegistrationType();
   Type *getCXXEHRegistrationType();
 
   // Per-module data.
   Module *TheModule = nullptr;
   StructType *EHLinkRegistrationTy = nullptr;
   StructType *CXXEHRegistrationTy = nullptr;
   StructType *SEHRegistrationTy = nullptr;
-  Constant *SetJmp3 = nullptr;
-  Constant *CxxLongjmpUnwind = nullptr;
+  FunctionCallee SetJmp3 = nullptr;
+  FunctionCallee CxxLongjmpUnwind = nullptr;
 
   // Per-function state
   EHPersonality Personality = EHPersonality::Unknown;
   Function *PersonalityFn = nullptr;
   bool UseStackGuard = false;
   int ParentBaseState;
-  Constant *SehLongjmpUnwind = nullptr;
+  FunctionCallee SehLongjmpUnwind = nullptr;
   Constant *Cookie = nullptr;
 
   /// The stack allocation containing all EH data, including the link in the
   /// fs:00 chain and the current state.
   AllocaInst *RegNode = nullptr;
 
   // The allocation containing the EH security guard.
   AllocaInst *EHGuardNode = nullptr;
if (Personality == EHPersonality::MSVC_CXX) {
     // Handler = __ehhandler$F
     Function *Trampoline = generateLSDAInEAXThunk(F);
     Link = Builder.CreateStructGEP(RegNodeTy, RegNode, 1);
     linkExceptionRegistration(Builder, Trampoline);
 
     CxxLongjmpUnwind = TheModule->getOrInsertFunction(
         "__CxxLongjmpUnwind",
         FunctionType::get(VoidTy, Int8PtrType, /*isVarArg=*/false));
-    cast<Function>(CxxLongjmpUnwind->stripPointerCasts())
+    cast<Function>(CxxLongjmpUnwind.getCallee()->stripPointerCasts())
         ->setCallingConv(CallingConv::X86_StdCall);
   } else if (Personality == EHPersonality::MSVC_X86SEH) {
     // If _except_handler4 is in use, some additional guard checks and prologue
     // stuff is required.
     StringRef PersonalityName = PersonalityFn->getName();
     UseStackGuard = (PersonalityName == "_except_handler4");
 
     // Allocate local structures.
if (Personality == EHPersonality::MSVC_CXX) {
     // Register the exception handler.
     Link = Builder.CreateStructGEP(RegNodeTy, RegNode, 2);
     linkExceptionRegistration(Builder, PersonalityFn);
 
     SehLongjmpUnwind = TheModule->getOrInsertFunction(
         UseStackGuard ? "_seh_longjmp_unwind4" : "_seh_longjmp_unwind",
         FunctionType::get(Type::getVoidTy(TheModule->getContext()), Int8PtrType,
                           /*isVarArg=*/false));
-    cast<Function>(SehLongjmpUnwind->stripPointerCasts())
+    cast<Function>(SehLongjmpUnwind.getCallee()->stripPointerCasts())
         ->setCallingConv(CallingConv::X86_StdCall);
   } else {
     llvm_unreachable("unexpected personality function");
   }
 
   // Insert an unlink before all returns.
   for (BasicBlock &BB : *F) {
     Instruction *T = BB.getTerminator();
void WinEHStatePass::rewriteSetJmpCallSite(IRBuilder<> &Builder, Function &F,
 
   Instruction *Inst = CS.getInstruction();
 
   SmallVector<OperandBundleDef, 1> OpBundles;
   CS.getOperandBundlesAsDefs(OpBundles);
 
   SmallVector<Value *, 3> OptionalArgs;
   if (Personality == EHPersonality::MSVC_CXX) {
-    OptionalArgs.push_back(CxxLongjmpUnwind);
+    OptionalArgs.push_back(CxxLongjmpUnwind.getCallee());
     OptionalArgs.push_back(State);
     OptionalArgs.push_back(emitEHLSDA(Builder, &F));
   } else if (Personality == EHPersonality::MSVC_X86SEH) {
-    OptionalArgs.push_back(SehLongjmpUnwind);
+    OptionalArgs.push_back(SehLongjmpUnwind.getCallee());
     OptionalArgs.push_back(State);
     if (UseStackGuard)
       OptionalArgs.push_back(Cookie);
   } else {
     llvm_unreachable("unhandled personality!");
   }
 
   SmallVector<Value *, 5> Args;
void WinEHStatePass::addStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
 
   SmallVector<CallSite, 1> SetJmp3CallSites;
   for (BasicBlock *BB : RPOT) {
     for (Instruction &I : *BB) {
       CallSite CS(&I);
       if (!CS)
         continue;
       if (CS.getCalledValue()->stripPointerCasts() !=
-          SetJmp3->stripPointerCasts())
+          SetJmp3.getCallee()->stripPointerCasts())
         continue;
 
       SetJmp3CallSites.push_back(CS);
     }
   }
 
   for (CallSite CS : SetJmp3CallSites) {
     auto &BBColors = BlockColors[CS->getParent()];

llvm/lib/Transforms/IPO/CrossDSOCFI.cpp

for (auto Func : CfiFunctionsMD->operands()) {
       for (unsigned I = 2; I < Func->getNumOperands(); ++I)
         if (ConstantInt *TypeId =
                 extractNumericTypeId(cast<MDNode>(Func->getOperand(I).get())))
           TypeIds.insert(TypeId->getZExtValue());
     }
   }
 
   LLVMContext &Ctx = M.getContext();
-  Constant *C = M.getOrInsertFunction(
+  FunctionCallee C = M.getOrInsertFunction(
       "__cfi_check", Type::getVoidTy(Ctx), Type::getInt64Ty(Ctx),
       Type::getInt8PtrTy(Ctx), Type::getInt8PtrTy(Ctx));
-  Function *F = dyn_cast<Function>(C);
+  Function *F = dyn_cast<Function>(C.getCallee());
   // Take over the existing function. The frontend emits a weak stub so that the
   // linker knows about the symbol; this pass replaces the function body.
   F->deleteBody();
   F->setAlignment(4096);
 
   Triple T(M.getTargetTriple());
   if (T.isARM() || T.isThumb())
     F->addFnAttr("target-features", "+thumb-mode");
 
   auto args = F->arg_begin();
   Value &CallSiteTypeId = *(args++);
   CallSiteTypeId.setName("CallSiteTypeId");
   Value &Addr = *(args++);
   Addr.setName("Addr");
   Value &CFICheckFailData = *(args++);
   CFICheckFailData.setName("CFICheckFailData");
   assert(args == F->arg_end());
 
   BasicBlock *BB = BasicBlock::Create(Ctx, "entry", F);
   BasicBlock *ExitBB = BasicBlock::Create(Ctx, "exit", F);
 
   BasicBlock *TrapBB = BasicBlock::Create(Ctx, "fail", F);
   IRBuilder<> IRBFail(TrapBB);
-  Constant *CFICheckFailFn = M.getOrInsertFunction(
-      "__cfi_check_fail", Type::getVoidTy(Ctx), Type::getInt8PtrTy(Ctx),
-      Type::getInt8PtrTy(Ctx));
+  FunctionCallee CFICheckFailFn =
+      M.getOrInsertFunction("__cfi_check_fail", Type::getVoidTy(Ctx),
+                            Type::getInt8PtrTy(Ctx), Type::getInt8PtrTy(Ctx));
   IRBFail.CreateCall(CFICheckFailFn, {&CFICheckFailData, &Addr});
   IRBFail.CreateBr(ExitBB);
 
   IRBuilder<> IRBExit(ExitBB);
   IRBExit.CreateRetVoid();
 
   IRBuilder<> IRB(BB);
   SwitchInst *SI = IRB.CreateSwitch(&CallSiteTypeId, TrapBB, TypeIds.size());

llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp

void DevirtModule::importResolution(VTableSlot Slot, VTableSlotInfo &SlotInfo) {
   auto ResI = TidSummary->WPDRes.find(Slot.ByteOffset);
   if (ResI == TidSummary->WPDRes.end())
     return;
   const WholeProgramDevirtResolution &Res = ResI->second;
 
   if (Res.TheKind == WholeProgramDevirtResolution::SingleImpl) {
     // The type of the function in the declaration is irrelevant because every
     // call site will cast it to the correct type.
-    auto *SingleImpl = M.getOrInsertFunction(
-        Res.SingleImplName, Type::getVoidTy(M.getContext()));
+    Constant *SingleImpl =
+        cast<Constant>(M.getOrInsertFunction(Res.SingleImplName,
+                                             Type::getVoidTy(M.getContext()))
+                           .getCallee());
 
     // This is the import phase so we should not be exporting anything.
     bool IsExported = false;
     applySingleImplDevirt(SlotInfo, SingleImpl, IsExported);
     assert(!IsExported);
   }
 
   for (auto &CSByConstantArg : SlotInfo.ConstCSInfo) {
case WholeProgramDevirtResolution::ByArg::VirtualConstProp: {
       break;
     }
     default:
       break;
     }
   }
 
   if (Res.TheKind == WholeProgramDevirtResolution::BranchFunnel) {
-    auto *JT = M.getOrInsertFunction(getGlobalName(Slot, {}, "branch_funnel"),
-                                     Type::getVoidTy(M.getContext()));
+    // The type of the function is irrelevant, because it's bitcast at calls
+    // anyhow.
+    Constant *JT = cast<Constant>(
+        M.getOrInsertFunction(getGlobalName(Slot, {}, "branch_funnel"),
+                              Type::getVoidTy(M.getContext()))
+            .getCallee());
     bool IsExported = false;
     applyICallBranchFunnel(SlotInfo, JT, IsExported);
     assert(!IsExported);
   }
 }
 
 void DevirtModule::removeRedundantTypeTests() {
   auto True = ConstantInt::getTrue(M.getContext());

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

private:
   Triple TargetTriple;
   int LongSize;
   bool CompileKernel;
   bool Recover;
   bool UseAfterScope;
   Type *IntptrTy;
   ShadowMapping Mapping;
   DominatorTree *DT;
-  Function *AsanHandleNoReturnFunc;
-  Function *AsanPtrCmpFunction, *AsanPtrSubFunction;
+  FunctionCallee AsanHandleNoReturnFunc;
+  FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
   Constant *AsanShadowGlobal;
 
   // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
-  Function *AsanErrorCallback[2][2][kNumberOfAccessSizes];
-  Function *AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
+  FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
+  FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
 
   // These arrays is indexed by AccessIsWrite and Experiment.
-  Function *AsanErrorCallbackSized[2][2];
-  Function *AsanMemoryAccessCallbackSized[2][2];
+  FunctionCallee AsanErrorCallbackSized[2][2];
+  FunctionCallee AsanMemoryAccessCallbackSized[2][2];
 
-  Function *AsanMemmove, *AsanMemcpy, *AsanMemset;
+  FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
   InlineAsm *EmptyAsm;
   Value *LocalDynamicShadow = nullptr;
   GlobalsMetadata GlobalsMD;
   DenseMap<const AllocaInst *, bool> ProcessedAllocas;
 };
 
 class AddressSanitizerModule : public ModulePass {
 public:
private:
   bool UseGlobalsGC;
   bool UsePrivateAlias;
   bool UseOdrIndicator;
   bool UseCtorComdat;
   Type *IntptrTy;
   LLVMContext *C;
   Triple TargetTriple;
   ShadowMapping Mapping;
-  Function *AsanPoisonGlobals;
-  Function *AsanUnpoisonGlobals;
-  Function *AsanRegisterGlobals;
-  Function *AsanUnregisterGlobals;
-  Function *AsanRegisterImageGlobals;
-  Function *AsanUnregisterImageGlobals;
-  Function *AsanRegisterElfGlobals;
-  Function *AsanUnregisterElfGlobals;
+  FunctionCallee AsanPoisonGlobals;
+  FunctionCallee AsanUnpoisonGlobals;
+  FunctionCallee AsanRegisterGlobals;
+  FunctionCallee AsanUnregisterGlobals;
+  FunctionCallee AsanRegisterImageGlobals;
+  FunctionCallee AsanUnregisterImageGlobals;
+  FunctionCallee AsanRegisterElfGlobals;
+  FunctionCallee AsanUnregisterElfGlobals;
 
   Function *AsanCtorFunction = nullptr;
   Function *AsanDtorFunction = nullptr;
 };
 
 // Stack poisoning does not play well with exception handling.
 // When an exception is thrown, we essentially bypass the code
 // that unpoisones the stack. This is why the run-time library has
struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
   Type *IntptrPtrTy;
   ShadowMapping Mapping;
 
   SmallVector<AllocaInst *, 16> AllocaVec;
   SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
   SmallVector<Instruction *, 8> RetVec;
   unsigned StackAlignment;
 
-  Function *AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
-      *AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
-  Function *AsanSetShadowFunc[0x100] = {};
-  Function *AsanPoisonStackMemoryFunc, *AsanUnpoisonStackMemoryFunc;
-  Function *AsanAllocaPoisonFunc, *AsanAllocasUnpoisonFunc;
+  FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
+      AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
+  FunctionCallee AsanSetShadowFunc[0x100] = {};
+  FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
+  FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;
 
   // Stores a place and arguments of poisoning/unpoisoning call for alloca.
   struct AllocaPoisonCall {
     IntrinsicInst *InsBefore;
     AllocaInst *AI;
     uint64_t Size;
     bool DoPoison;
   };
bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
   // have to instrument it.  However, if a global does not have initializer
   // at all, we assume it has dynamic initializer (in other TU).
   return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
 }
 
 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
     Instruction *I) {
   IRBuilder<> IRB(I);
-  Function *F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
+  FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
   Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
   for (Value *&i : Param) {
     if (i->getType()->isPointerTy())
       i = IRB.CreatePointerCast(i, IntptrTy);
   }
   IRB.CreateCall(F, Param);
 }
 
StringRef AddressSanitizerModule::getGlobalMetadataSection() const {
   }
   llvm_unreachable("unsupported object format");
 }
 
 void AddressSanitizerModule::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(*C);
 
   // Declare our poisoning and unpoisoning functions.
-  AsanPoisonGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy));
-  AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
-  AsanUnpoisonGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      kAsanUnpoisonGlobalsName, IRB.getVoidTy()));
-  AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
+  AsanPoisonGlobals =
+      M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
+  AsanUnpoisonGlobals =
+      M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());
 
   // Declare functions that register/unregister globals.
-  AsanRegisterGlobals = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy));
-  AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
-  AsanUnregisterGlobals = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(kAsanUnregisterGlobalsName, IRB.getVoidTy(),
-                            IntptrTy, IntptrTy));
-  AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
+  AsanRegisterGlobals = M.getOrInsertFunction(
+      kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
+  AsanUnregisterGlobals = M.getOrInsertFunction(
+      kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
 
   // Declare the functions that find globals in a shared object and then invoke
   // the (un)register function on them.
-  AsanRegisterImageGlobals =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
-  AsanRegisterImageGlobals->setLinkage(Function::ExternalLinkage);
-
-  AsanUnregisterImageGlobals =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy));
-  AsanUnregisterImageGlobals->setLinkage(Function::ExternalLinkage);
+  AsanRegisterImageGlobals = M.getOrInsertFunction(
+      kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
+  AsanUnregisterImageGlobals = M.getOrInsertFunction(
+      kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
 
-  AsanRegisterElfGlobals = checkSanitizerInterfaceFunction(
+  AsanRegisterElfGlobals =
       M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
-                            IntptrTy, IntptrTy, IntptrTy));
-  AsanRegisterElfGlobals->setLinkage(Function::ExternalLinkage);
-
-  AsanUnregisterElfGlobals = checkSanitizerInterfaceFunction(
+                            IntptrTy, IntptrTy, IntptrTy);
+  AsanUnregisterElfGlobals =
       M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
-                            IntptrTy, IntptrTy, IntptrTy));
-  AsanUnregisterElfGlobals->setLinkage(Function::ExternalLinkage);
+                            IntptrTy, IntptrTy, IntptrTy);
 }
 
 // Put the metadata and the instrumented global in the same group. This ensures
 // that the metadata is discarded if the instrumented global is discarded.
 void AddressSanitizerModule::SetComdatForGlobalMetadata(
     GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
   Module &M = *G->getParent();
   Comdat *C = G->getComdat();
for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
 
       SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
       SmallVector<Type *, 2> Args1{1, IntptrTy};
       if (Exp) {
         Type *ExpType = Type::getInt32Ty(*C);
         Args2.push_back(ExpType);
         Args1.push_back(ExpType);
       }
-      AsanErrorCallbackSized[AccessIsWrite][Exp] =
-          checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-              kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
-              FunctionType::get(IRB.getVoidTy(), Args2, false)));
+      AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
+          FunctionType::get(IRB.getVoidTy(), Args2, false));
 
-      AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] =
-          checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-              ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
-              FunctionType::get(IRB.getVoidTy(), Args2, false)));
+      AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
+          FunctionType::get(IRB.getVoidTy(), Args2, false));
 
       for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
            AccessSizeIndex++) {
         const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
         AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
-            checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+            M.getOrInsertFunction(
                 kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
-                FunctionType::get(IRB.getVoidTy(), Args1, false)));
+                FunctionType::get(IRB.getVoidTy(), Args1, false));
 
         AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
-            checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+            M.getOrInsertFunction(
                 ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
-                FunctionType::get(IRB.getVoidTy(), Args1, false)));
+                FunctionType::get(IRB.getVoidTy(), Args1, false));
       }
     }
   }
 
   const std::string MemIntrinCallbackPrefix =
       CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
-  AsanMemmove = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      MemIntrinCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
-      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
-  AsanMemcpy = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      MemIntrinCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
-      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
-  AsanMemset = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      MemIntrinCallbackPrefix + "memset", IRB.getInt8PtrTy(),
-      IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy));
-
-  AsanHandleNoReturnFunc = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy()));
-
-  AsanPtrCmpFunction = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy));
-  AsanPtrSubFunction = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy));
+  AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
+                                      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+                                      IRB.getInt8PtrTy(), IntptrTy);
+  AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
+                                     IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+                                     IRB.getInt8PtrTy(), IntptrTy);
+  AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
+                                     IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+                                     IRB.getInt32Ty(), IntptrTy);
+
+  AsanHandleNoReturnFunc =
+      M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());
+
+  AsanPtrCmpFunction =
+      M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
+  AsanPtrSubFunction =
+      M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
   // We insert an empty inline asm after __asan_report* to avoid callback merge.
   EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
                             StringRef(""), StringRef(""),
                             /*hasSideEffects=*/true);
   if (Mapping.InGlobal)
     AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
                                            ArrayType::get(IRB.getInt8Ty(), 0));
 }
bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
   // For each NSObject descendant having a +load method, this method is invoked
   // by the ObjC runtime before any of the static constructors is called.
   // Therefore we need to instrument such methods with a call to __asan_init
   // at the beginning in order to initialize our runtime before any access to
   // the shadow memory.
   // We cannot just ignore these methods, because they may call other
   // instrumented functions.
   if (F.getName().find(" load]") != std::string::npos) {
-    Function *AsanInitFunction =
+    FunctionCallee AsanInitFunction =
         declareSanitizerInitFunction(*F.getParent(), kAsanInitName, {});
     IRBuilder<> IRB(&F.front(), F.front().begin());
     IRB.CreateCall(AsanInitFunction, {});
     return true;
   }
   return false;
 }
 
bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
   // We have inline assembly with quite a few arguments.
   return true;
 }
 
 void FunctionStackPoisoner::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(*C);
   for (int i = 0; i <= kMaxAsanStackMallocSizeClass; i++) {
     std::string Suffix = itostr(i);
-    AsanStackMallocFunc[i] = checkSanitizerInterfaceFunction(
-        M.getOrInsertFunction(kAsanStackMallocNameTemplate + Suffix, IntptrTy,
-                              IntptrTy));
-    AsanStackFreeFunc[i] = checkSanitizerInterfaceFunction(
+    AsanStackMallocFunc[i] = M.getOrInsertFunction(
+        kAsanStackMallocNameTemplate + Suffix, IntptrTy, IntptrTy);
+    AsanStackFreeFunc[i] =
         M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
-                              IRB.getVoidTy(), IntptrTy, IntptrTy));
+                              IRB.getVoidTy(), IntptrTy, IntptrTy);
   }
   if (ASan.UseAfterScope) {
-    AsanPoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
-        M.getOrInsertFunction(kAsanPoisonStackMemoryName, IRB.getVoidTy(),
-                              IntptrTy, IntptrTy));
-    AsanUnpoisonStackMemoryFunc = checkSanitizerInterfaceFunction(
-        M.getOrInsertFunction(kAsanUnpoisonStackMemoryName, IRB.getVoidTy(),
-                              IntptrTy, IntptrTy));
+    AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
+        kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
+    AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
+        kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
   }
 
   for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
     std::ostringstream Name;
     Name << kAsanSetShadowPrefix;
     Name << std::setw(2) << std::setfill('0') << std::hex << Val;
     AsanSetShadowFunc[Val] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy));
+        M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
   }
 
-  AsanAllocaPoisonFunc = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
-  AsanAllocasUnpoisonFunc =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy));
+  AsanAllocaPoisonFunc = M.getOrInsertFunction(
+      kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
+  AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
+      kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
 }
 
 void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
                                                ArrayRef<uint8_t> ShadowBytes,
                                                size_t Begin, size_t End,
                                                IRBuilder<> &IRB,
                                                Value *ShadowBase) {
   if (Begin >= End)

llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp

class DataFlowSanitizer : public ModulePass {
   Constant *GetRetvalTLS;
   Constant *ExternalShadowMask;
   FunctionType *DFSanUnionFnTy;
   FunctionType *DFSanUnionLoadFnTy;
   FunctionType *DFSanUnimplementedFnTy;
   FunctionType *DFSanSetLabelFnTy;
   FunctionType *DFSanNonzeroLabelFnTy;
   FunctionType *DFSanVarargWrapperFnTy;
-  Constant *DFSanUnionFn;
-  Constant *DFSanCheckedUnionFn;
-  Constant *DFSanUnionLoadFn;
-  Constant *DFSanUnimplementedFn;
-  Constant *DFSanSetLabelFn;
-  Constant *DFSanNonzeroLabelFn;
-  Constant *DFSanVarargWrapperFn;
+  FunctionCallee DFSanUnionFn;
+  FunctionCallee DFSanCheckedUnionFn;
+  FunctionCallee DFSanUnionLoadFn;
+  FunctionCallee DFSanUnimplementedFn;
+  FunctionCallee DFSanSetLabelFn;
+  FunctionCallee DFSanNonzeroLabelFn;
+  FunctionCallee DFSanVarargWrapperFn;
   MDNode *ColdCallWeights;
   DFSanABIList ABIList;
   DenseMap<Value *, Function *> UnwrappedFnMap;
   AttrBuilder ReadOnlyNoneAttrs;
   bool DFSanRuntimeShadowMask = false;
 
   Value *getShadowAddress(Value *Addr, Instruction *Pos);
   bool isInstrumented(const Function *F);
DataFlowSanitizer::buildWrapperFunction(Function *F, StringRef NewFName,
   }
 
   return NewF;
 }
 
 Constant *DataFlowSanitizer::getOrBuildTrampolineFunction(FunctionType *FT,
                                                           StringRef FName) {
   FunctionType *FTT = getTrampolineFunctionType(FT);
-  Constant *C = Mod->getOrInsertFunction(FName, FTT);
-  Function *F = dyn_cast<Function>(C);
+  FunctionCallee C = Mod->getOrInsertFunction(FName, FTT);
+  Function *F = dyn_cast<Function>(C.getCallee());
   if (F && F->isDeclaration()) {
     F->setLinkage(GlobalValue::LinkOnceODRLinkage);
     BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", F);
     std::vector<Value *> Args;
     Function::arg_iterator AI = F->arg_begin(); ++AI;
     for (unsigned N = FT->getNumParams(); N != 0; ++AI, --N)
       Args.push_back(&*AI);
     CallInst *CI = CallInst::Create(&*F->arg_begin(), Args, "", BB);
     ReturnInst *RI;
     if (FT->getReturnType()->isVoidTy())
       RI = ReturnInst::Create(*Ctx, BB);
     else
       RI = ReturnInst::Create(*Ctx, CI, BB);
 
     DFSanFunction DFSF(*this, F, /*IsNativeABI=*/true);
     Function::arg_iterator ValAI = F->arg_begin(), ShadowAI = AI; ++ValAI;
     for (unsigned N = FT->getNumParams(); N != 0; ++ValAI, ++ShadowAI, --N)
       DFSF.ValShadowMap[&*ValAI] = &*ShadowAI;
     DFSanVisitor(DFSF).visitCallInst(*CI);
     if (!FT->getReturnType()->isVoidTy())
       new StoreInst(DFSF.getShadow(RI->getReturnValue()),
                     &*std::prev(F->arg_end()), RI);
   }
 
-  return C;
+  return cast<Constant>(C.getCallee());
 }
 
 bool DataFlowSanitizer::runOnModule(Module &M) {
   if (ABIList.isIn(M, "skip"))
     return false;
 
   if (!GetArgTLSPtr) {
     Type *ArgTLSTy = ArrayType::get(ShadowTy, 64);
     ArgTLS = Mod->getOrInsertGlobal("__dfsan_arg_tls", ArgTLSTy);
     if (GlobalVariable *G = dyn_cast<GlobalVariable>(ArgTLS))
       G->setThreadLocalMode(GlobalVariable::InitialExecTLSModel);
   }
   if (!GetRetvalTLSPtr) {
     RetvalTLS = Mod->getOrInsertGlobal("__dfsan_retval_tls", ShadowTy);
     if (GlobalVariable *G = dyn_cast<GlobalVariable>(RetvalTLS))
       G->setThreadLocalMode(GlobalVariable::InitialExecTLSModel);
   }
 
   ExternalShadowMask =
       Mod->getOrInsertGlobal(kDFSanExternShadowPtrMask, IntptrTy);
 
-  DFSanUnionFn = Mod->getOrInsertFunction("__dfsan_union", DFSanUnionFnTy);
-  if (Function *F = dyn_cast<Function>(DFSanUnionFn)) {
-    F->addAttribute(AttributeList::FunctionIndex, Attribute::NoUnwind);
-    F->addAttribute(AttributeList::FunctionIndex, Attribute::ReadNone);
-    F->addAttribute(AttributeList::ReturnIndex, Attribute::ZExt);
-    F->addParamAttr(0, Attribute::ZExt);
-    F->addParamAttr(1, Attribute::ZExt);
-  }
-  DFSanCheckedUnionFn = Mod->getOrInsertFunction("dfsan_union", DFSanUnionFnTy);
-  if (Function *F = dyn_cast<Function>(DFSanCheckedUnionFn)) {
-    F->addAttribute(AttributeList::FunctionIndex, Attribute::NoUnwind);
-    F->addAttribute(AttributeList::FunctionIndex, Attribute::ReadNone);
-    F->addAttribute(AttributeList::ReturnIndex, Attribute::ZExt);
-    F->addParamAttr(0, Attribute::ZExt);
-    F->addParamAttr(1, Attribute::ZExt);
-  }
+  {
+    AttributeList AL;
+    AL = AL.addAttribute(M.getContext(), AttributeList::FunctionIndex,
+                         Attribute::NoUnwind);
+    AL = AL.addAttribute(M.getContext(), AttributeList::FunctionIndex,
+                         Attribute::ReadNone);
+    AL = AL.addAttribute(M.getContext(), AttributeList::ReturnIndex,
+                         Attribute::ZExt);
+    AL = AL.addParamAttribute(M.getContext(), 0, Attribute::ZExt);
+    AL = AL.addParamAttribute(M.getContext(), 1, Attribute::ZExt);
+    DFSanUnionFn =
+        Mod->getOrInsertFunction("__dfsan_union", DFSanUnionFnTy, AL);
+  }
+
+  {
+    AttributeList AL;
+    AL = AL.addAttribute(M.getContext(), AttributeList::FunctionIndex,
+                         Attribute::NoUnwind);
+    AL = AL.addAttribute(M.getContext(), AttributeList::FunctionIndex,
+                         Attribute::ReadNone);
+    AL = AL.addAttribute(M.getContext(), AttributeList::ReturnIndex,
+                         Attribute::ZExt);
+    AL = AL.addParamAttribute(M.getContext(), 0, Attribute::ZExt);
+    AL = AL.addParamAttribute(M.getContext(), 1, Attribute::ZExt);
+    DFSanCheckedUnionFn =
+        Mod->getOrInsertFunction("dfsan_union", DFSanUnionFnTy, AL);
+  }
+  {
+    AttributeList AL;
+    AL = AL.addAttribute(M.getContext(), AttributeList::FunctionIndex,
+                         Attribute::NoUnwind);
+    AL = AL.addAttribute(M.getContext(), AttributeList::FunctionIndex,
+                         Attribute::ReadOnly);
+    AL = AL.addAttribute(M.getContext(), AttributeList::ReturnIndex,
+                         Attribute::ZExt);
     DFSanUnionLoadFn =
-      Mod->getOrInsertFunction("__dfsan_union_load", DFSanUnionLoadFnTy);
-  if (Function *F = dyn_cast<Function>(DFSanUnionLoadFn)) {
-    F->addAttribute(AttributeList::FunctionIndex, Attribute::NoUnwind);
-    F->addAttribute(AttributeList::FunctionIndex, Attribute::ReadOnly);
-    F->addAttribute(AttributeList::ReturnIndex, Attribute::ZExt);
+        Mod->getOrInsertFunction("__dfsan_union_load", DFSanUnionLoadFnTy, AL);
   }
   DFSanUnimplementedFn =
       Mod->getOrInsertFunction("__dfsan_unimplemented", DFSanUnimplementedFnTy);
+  {
+    AttributeList AL;
+    AL = AL.addParamAttribute(M.getContext(), 0, Attribute::ZExt);
     DFSanSetLabelFn =
-      Mod->getOrInsertFunction("__dfsan_set_label", DFSanSetLabelFnTy);
-  if (Function *F = dyn_cast<Function>(DFSanSetLabelFn)) {
-    F->addParamAttr(0, Attribute::ZExt);
+        Mod->getOrInsertFunction("__dfsan_set_label", DFSanSetLabelFnTy, AL);
   }
   DFSanNonzeroLabelFn =
       Mod->getOrInsertFunction("__dfsan_nonzero_label", DFSanNonzeroLabelFnTy);
   DFSanVarargWrapperFn = Mod->getOrInsertFunction("__dfsan_vararg_wrapper",
                                                   DFSanVarargWrapperFnTy);
 
   std::vector<Function *> FnsToInstrument;
   SmallPtrSet<Function *, 2> FnsWithNativeABI;
   for (Function &i : M) {
     if (!i.isIntrinsic() &&
-        &i != DFSanUnionFn &&
-        &i != DFSanCheckedUnionFn &&
-        &i != DFSanUnionLoadFn &&
-        &i != DFSanUnimplementedFn &&
-        &i != DFSanSetLabelFn &&
-        &i != DFSanNonzeroLabelFn &&
-        &i != DFSanVarargWrapperFn)
+        &i != DFSanUnionFn.getCallee()->stripPointerCasts() &&
+        &i != DFSanCheckedUnionFn.getCallee()->stripPointerCasts() &&
+        &i != DFSanUnionLoadFn.getCallee()->stripPointerCasts() &&
+        &i != DFSanUnimplementedFn.getCallee()->stripPointerCasts() &&
+        &i != DFSanSetLabelFn.getCallee()->stripPointerCasts() &&
+        &i != DFSanNonzeroLabelFn.getCallee()->stripPointerCasts() &&
+        &i != DFSanVarargWrapperFn.getCallee()->stripPointerCasts())
       FnsToInstrument.push_back(&i);
   }
 
   // Give function aliases prefixes when necessary, and build wrappers where the
   // instrumentedness is inconsistent.
   for (Module::alias_iterator i = M.alias_begin(), e = M.alias_end(); i != e;) {
     GlobalAlias *GA = &*i;
     ++i;
void DFSanVisitor::visitCallSite(CallSite CS) {
   Function *F = CS.getCalledFunction();
   if ((F && F->isIntrinsic()) || isa<InlineAsm>(CS.getCalledValue())) {
     visitOperandShadowInst(*CS.getInstruction());
     return;
   }
 
   // Calls to this function are synthesized in wrappers, and we shouldn't
   // instrument them.
-  if (F == DFSF.DFS.DFSanVarargWrapperFn)
+  if (F == DFSF.DFS.DFSanVarargWrapperFn.getCallee()->stripPointerCasts())
     return;
 
   IRBuilder<> IRB(CS.getInstruction());
 
   DenseMap<Value *, Function *>::iterator i =
       DFSF.DFS.UnwrappedFnMap.find(CS.getCalledValue());
   if (i != DFSF.DFS.UnwrappedFnMap.end()) {
     Function *F = i->second;
case DataFlowSanitizer::WK_Custom:
       // Don't try to handle invokes of custom functions, it's too complicated.
       // Instead, invoke the dfsw$ wrapper, which will in turn call the __dfsw_
       // wrapper.
       if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
         FunctionType *FT = F->getFunctionType();
         TransformedFunction CustomFn = DFSF.DFS.getCustomFunctionType(FT);
         std::string CustomFName = "__dfsw_";
         CustomFName += F->getName();
-        Constant *CustomF = DFSF.DFS.Mod->getOrInsertFunction(
+        FunctionCallee CustomF = DFSF.DFS.Mod->getOrInsertFunction(
             CustomFName, CustomFn.TransformedType);
-        if (Function *CustomFn = dyn_cast<Function>(CustomF)) {
+        if (Function *CustomFn = dyn_cast<Function>(CustomF.getCallee())) {
           CustomFn->copyAttributesFrom(F);
 
           // Custom functions returning non-void will write to the return label.
           if (!FT->getReturnType()->isVoidTy()) {
             CustomFn->removeAttributes(AttributeList::FunctionIndex,
                                        DFSF.DFS.ReadOnlyNoneAttrs);
           }
         }

llvm/lib/Transforms/Instrumentation/EfficiencySanitizer.cpp

bool instrumentFastpathWorkingSet(Instruction *I, const DataLayout &DL,
                                     Value *Addr, unsigned Alignment);
 
   EfficiencySanitizerOptions Options;
   LLVMContext *Ctx;
   Type *IntptrTy;
   // Our slowpath involves callouts to the runtime library.
   // Access sizes are powers of two: 1, 2, 4, 8, 16.
   static const size_t NumberOfAccessSizes = 5;
-  Function *EsanAlignedLoad[NumberOfAccessSizes];
-  Function *EsanAlignedStore[NumberOfAccessSizes];
-  Function *EsanUnalignedLoad[NumberOfAccessSizes];
-  Function *EsanUnalignedStore[NumberOfAccessSizes];
+  FunctionCallee EsanAlignedLoad[NumberOfAccessSizes];
+  FunctionCallee EsanAlignedStore[NumberOfAccessSizes];
+  FunctionCallee EsanUnalignedLoad[NumberOfAccessSizes];
+  FunctionCallee EsanUnalignedStore[NumberOfAccessSizes];
   // For irregular sizes of any alignment:
-  Function *EsanUnalignedLoadN, *EsanUnalignedStoreN;
-  Function *MemmoveFn, *MemcpyFn, *MemsetFn;
+  FunctionCallee EsanUnalignedLoadN, EsanUnalignedStoreN;
+  FunctionCallee MemmoveFn, MemcpyFn, MemsetFn;
   Function *EsanCtorFunction;
   Function *EsanDtorFunction;
   // Remember the counter variable for each struct type to avoid
   // recomputing the variable name later during instrumentation.
   std::map<Type *, GlobalVariable *> StructTyMap;
   ShadowMemoryParams ShadowParams;
 };
 } // namespace
void EfficiencySanitizer::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(M.getContext());
   // Initialize the callbacks.
   for (size_t Idx = 0; Idx < NumberOfAccessSizes; ++Idx) {
     const unsigned ByteSize = 1U << Idx;
     std::string ByteSizeStr = utostr(ByteSize);
     // We'll inline the most common (i.e., aligned and frequent sizes)
     // load + store instrumentation: these callouts are for the slowpath.
     SmallString<32> AlignedLoadName("__esan_aligned_load" + ByteSizeStr);
-    EsanAlignedLoad[Idx] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            AlignedLoadName, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    EsanAlignedLoad[Idx] = M.getOrInsertFunction(
+        AlignedLoadName, IRB.getVoidTy(), IRB.getInt8PtrTy());
     SmallString<32> AlignedStoreName("__esan_aligned_store" + ByteSizeStr);
-    EsanAlignedStore[Idx] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            AlignedStoreName, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    EsanAlignedStore[Idx] = M.getOrInsertFunction(
+        AlignedStoreName, IRB.getVoidTy(), IRB.getInt8PtrTy());
     SmallString<32> UnalignedLoadName("__esan_unaligned_load" + ByteSizeStr);
-    EsanUnalignedLoad[Idx] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            UnalignedLoadName, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    EsanUnalignedLoad[Idx] = M.getOrInsertFunction(
+        UnalignedLoadName, IRB.getVoidTy(), IRB.getInt8PtrTy());
     SmallString<32> UnalignedStoreName("__esan_unaligned_store" + ByteSizeStr);
-    EsanUnalignedStore[Idx] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            UnalignedStoreName, IRB.getVoidTy(), IRB.getInt8PtrTy()));
-  }
-  EsanUnalignedLoadN = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("__esan_unaligned_loadN", IRB.getVoidTy(),
-                            IRB.getInt8PtrTy(), IntptrTy));
-  EsanUnalignedStoreN = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("__esan_unaligned_storeN", IRB.getVoidTy(),
-                            IRB.getInt8PtrTy(), IntptrTy));
-  MemmoveFn = checkSanitizerInterfaceFunction(
+    EsanUnalignedStore[Idx] = M.getOrInsertFunction(
+        UnalignedStoreName, IRB.getVoidTy(), IRB.getInt8PtrTy());
+  }
+  EsanUnalignedLoadN = M.getOrInsertFunction(
+      "__esan_unaligned_loadN", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy);
+  EsanUnalignedStoreN = M.getOrInsertFunction(
+      "__esan_unaligned_storeN", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy);
+  MemmoveFn =
       M.getOrInsertFunction("memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
-                            IRB.getInt8PtrTy(), IntptrTy));
-  MemcpyFn = checkSanitizerInterfaceFunction(
+                            IRB.getInt8PtrTy(), IntptrTy);
+  MemcpyFn =
       M.getOrInsertFunction("memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
-                            IRB.getInt8PtrTy(), IntptrTy));
-  MemsetFn = checkSanitizerInterfaceFunction(
+                            IRB.getInt8PtrTy(), IntptrTy);
+  MemsetFn =
       M.getOrInsertFunction("memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
-                            IRB.getInt32Ty(), IntptrTy));
+                            IRB.getInt32Ty(), IntptrTy);
 }
 
 bool EfficiencySanitizer::shouldIgnoreStructType(StructType *StructTy) {
   if (StructTy == nullptr || StructTy->isOpaque() /* no struct body */)
     return true;
   return false;
 }
 

 void EfficiencySanitizer::createDestructor(Module &M, Constant *ToolInfoArg) {
   PointerType *Int8PtrTy = Type::getInt8PtrTy(*Ctx);
   EsanDtorFunction = Function::Create(FunctionType::get(Type::getVoidTy(*Ctx),
                                                         false),
                                       GlobalValue::InternalLinkage,
                                       EsanModuleDtorName, &M);
   ReturnInst::Create(*Ctx, BasicBlock::Create(*Ctx, "", EsanDtorFunction));
   IRBuilder<> IRB_Dtor(EsanDtorFunction->getEntryBlock().getTerminator());
-  Function *EsanExit = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(EsanExitName, IRB_Dtor.getVoidTy(),
-                            Int8PtrTy));
-  EsanExit->setLinkage(Function::ExternalLinkage);
+  FunctionCallee EsanExit =
+      M.getOrInsertFunction(EsanExitName, IRB_Dtor.getVoidTy(), Int8PtrTy);
   IRB_Dtor.CreateCall(EsanExit, {ToolInfoArg});
   appendToGlobalDtors(M, EsanDtorFunction, EsanCtorAndDtorPriority);
 }
 
 bool EfficiencySanitizer::initOnModule(Module &M) {
 
   Triple TargetTriple(M.getTargetTriple());
   if (TargetTriple.isMIPS64())
if (LoadInst *Load = dyn_cast<LoadInst>(I)) {
     IsStore = true;
     Alignment = 0;
     Addr = Xchg->getPointerOperand();
   } else
     llvm_unreachable("Unsupported mem access type");
 
   Type *OrigTy = cast<PointerType>(Addr->getType())->getElementType();
   const uint32_t TypeSizeBytes = DL.getTypeStoreSizeInBits(OrigTy) / 8;
-  Value *OnAccessFunc = nullptr;
+  FunctionCallee OnAccessFunc = nullptr;
 
   // Convert 0 to the default alignment.
   if (Alignment == 0)
     Alignment = DL.getPrefTypeAlignment(OrigTy);
 
   if (IsStore)
     NumInstrumentedStores++;
   else

llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp

private:
   bool emitProfileArcs();
 
   bool isFunctionInstrumented(const Function &F);
   std::vector<Regex> createRegexesFromString(StringRef RegexesStr);
   static bool doesFilenameMatchARegex(StringRef Filename,
                                       std::vector<Regex> &Regexes);
 
   // Get pointers to the functions in the runtime library.
-  Constant *getStartFileFunc();
-  Constant *getEmitFunctionFunc();
-  Constant *getEmitArcsFunc();
-  Constant *getSummaryInfoFunc();
-  Constant *getEndFileFunc();
+  FunctionCallee getStartFileFunc();
+  FunctionCallee getEmitFunctionFunc();
+  FunctionCallee getEmitArcsFunc();
+  FunctionCallee getSummaryInfoFunc();
+  FunctionCallee getEndFileFunc();
 
   // Add the function to write out all our counters to the global destructor
   // list.
   Function *
   insertCounterWriteout(ArrayRef<std::pair<GlobalVariable *, MDNode *>>);
   Function *insertFlush(ArrayRef<std::pair<GlobalVariable *, MDNode *>>);
 
   void AddFlushBeforeForkAndExec();
void GCOVProfiler::AddFlushBeforeForkAndExec() {
   }
 
   // We need to split the block after the fork/exec call
   // because else the counters for the lines after will be
   // the same as before the call.
   for (auto I : ForkAndExecs) {
     IRBuilder<> Builder(I);
     FunctionType *FTy = FunctionType::get(Builder.getVoidTy(), {}, false);
-    Constant *GCOVFlush = M->getOrInsertFunction("__gcov_flush", FTy);
+    FunctionCallee GCOVFlush = M->getOrInsertFunction("__gcov_flush", FTy);
     Builder.CreateCall(GCOVFlush);
     I->getParent()->splitBasicBlock(I);
   }
 }
 
 void GCOVProfiler::emitProfileNotes() {
   NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
   if (!CU_Nodes) return;
for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
     Type *Params[] = {
       PointerType::get(FTy, 0),
       PointerType::get(FTy, 0)
     };
     FTy = FunctionType::get(Builder.getVoidTy(), Params, false);
 
     // Initialize the environment and register the local writeout and flush
     // functions.
-    Constant *GCOVInit = M->getOrInsertFunction("llvm_gcov_init", FTy);
+    FunctionCallee GCOVInit = M->getOrInsertFunction("llvm_gcov_init", FTy);
     Builder.CreateCall(GCOVInit, {WriteoutF, FlushF});
     Builder.CreateRetVoid();
 
     appendToGlobalCtors(*M, F, 0);
   }
 
   return Result;
 }
 
-Constant *GCOVProfiler::getStartFileFunc() {
+FunctionCallee GCOVProfiler::getStartFileFunc() {
   Type *Args[] = {
     Type::getInt8PtrTy(*Ctx),  // const char *orig_filename
     Type::getInt8PtrTy(*Ctx),  // const char version[4]
     Type::getInt32Ty(*Ctx),    // uint32_t checksum
   };
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
-  auto *Res = M->getOrInsertFunction("llvm_gcda_start_file", FTy);
-  if (Function *FunRes = dyn_cast<Function>(Res))
-    if (auto AK = TLI->getExtAttrForI32Param(false))
-      FunRes->addParamAttr(2, AK);
+  AttributeList AL;
+    AL = AL.addParamAttribute(*Ctx, 2, AK);
+  FunctionCallee Res = M->getOrInsertFunction("llvm_gcda_start_file", FTy, AL);
   return Res;
-
 }
 
-Constant *GCOVProfiler::getEmitFunctionFunc() {
+FunctionCallee GCOVProfiler::getEmitFunctionFunc() {
   Type *Args[] = {
     Type::getInt32Ty(*Ctx),    // uint32_t ident
     Type::getInt8PtrTy(*Ctx),  // const char *function_name
     Type::getInt32Ty(*Ctx),    // uint32_t func_checksum
     Type::getInt8Ty(*Ctx),     // uint8_t use_extra_checksum
     Type::getInt32Ty(*Ctx),    // uint32_t cfg_checksum
   };
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
-  auto *Res = M->getOrInsertFunction("llvm_gcda_emit_function", FTy);
-  if (Function *FunRes = dyn_cast<Function>(Res))
-    if (auto AK = TLI->getExtAttrForI32Param(false)) {
-      FunRes->addParamAttr(0, AK);
-      FunRes->addParamAttr(2, AK);
-      FunRes->addParamAttr(3, AK);
-      FunRes->addParamAttr(4, AK);
-    }
-  return Res;
+  AttributeList AL;
+    AL = AL.addParamAttribute(*Ctx, 0, AK);
+    AL = AL.addParamAttribute(*Ctx, 2, AK);
+    AL = AL.addParamAttribute(*Ctx, 3, AK);
+    AL = AL.addParamAttribute(*Ctx, 4, AK);
+  return M->getOrInsertFunction("llvm_gcda_emit_function", FTy);
 }
 
-Constant *GCOVProfiler::getEmitArcsFunc() {
+FunctionCallee GCOVProfiler::getEmitArcsFunc() {
   Type *Args[] = {
     Type::getInt32Ty(*Ctx),     // uint32_t num_counters
     Type::getInt64PtrTy(*Ctx),  // uint64_t *counters
   };
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
-  auto *Res = M->getOrInsertFunction("llvm_gcda_emit_arcs", FTy);
-  if (Function *FunRes = dyn_cast<Function>(Res))
-    if (auto AK = TLI->getExtAttrForI32Param(false))
-      FunRes->addParamAttr(0, AK);
-  return Res;
+  AttributeList AL;
+    AL = AL.addParamAttribute(*Ctx, 0, AK);
+  return M->getOrInsertFunction("llvm_gcda_emit_arcs", FTy, AL);
 }
 
-Constant *GCOVProfiler::getSummaryInfoFunc() {
+FunctionCallee GCOVProfiler::getSummaryInfoFunc() {
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
   return M->getOrInsertFunction("llvm_gcda_summary_info", FTy);
 }
 
-Constant *GCOVProfiler::getEndFileFunc() {
+FunctionCallee GCOVProfiler::getEndFileFunc() {
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
   return M->getOrInsertFunction("llvm_gcda_end_file", FTy);
 }
 
 Function *GCOVProfiler::insertCounterWriteout(
     ArrayRef<std::pair<GlobalVariable *, MDNode *> > CountersBySP) {
   FunctionType *WriteoutFTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
   Function *WriteoutF = M->getFunction("__llvm_gcov_writeout");
   if (!WriteoutF)
     WriteoutF = Function::Create(WriteoutFTy, GlobalValue::InternalLinkage,
                                  "__llvm_gcov_writeout", M);
   WriteoutF->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
   WriteoutF->addFnAttr(Attribute::NoInline);
   if (Options.NoRedZone)
     WriteoutF->addFnAttr(Attribute::NoRedZone);
 
   BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", WriteoutF);
   IRBuilder<> Builder(BB);
 
-  Constant *StartFile = getStartFileFunc();
-  Constant *EmitFunction = getEmitFunctionFunc();
-  Constant *EmitArcs = getEmitArcsFunc();
-  Constant *SummaryInfo = getSummaryInfoFunc();
-  Constant *EndFile = getEndFileFunc();
+  FunctionCallee StartFile = getStartFileFunc();
+  FunctionCallee EmitFunction = getEmitFunctionFunc();
+  FunctionCallee EmitArcs = getEmitArcsFunc();
+  FunctionCallee SummaryInfo = getSummaryInfoFunc();
+  FunctionCallee EndFile = getEndFileFunc();
 
   NamedMDNode *CUNodes = M->getNamedMetadata("llvm.dbg.cu");
   if (!CUNodes) {
     Builder.CreateRetVoid();
     return WriteoutF;
   }
 
   // Collect the relevant data into a large constant data structure that we can

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

public:
 
   Value *getHwasanThreadSlotPtr(IRBuilder<> &IRB, Type *Ty);
   Value *emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord);
 
 private:
   LLVMContext *C;
   std::string CurModuleUniqueId;
   Triple TargetTriple;
-  Function *HWAsanMemmove, *HWAsanMemcpy, *HWAsanMemset;
+  FunctionCallee HWAsanMemmove, HWAsanMemcpy, HWAsanMemset;
 
   // Frame description is a way to pass names/sizes of local variables
   // to the run-time w/o adding extra executable code in every function.
   // We do this by creating a separate section with {PC,Descr} pairs and passing
   // the section beg/end to __hwasan_init_frames() at module init time.
   std::string createFrameString(ArrayRef<AllocaInst*> Allocas);
   void createFrameGlobal(Function &F, const std::string &FrameString);
   // Get the section name for frame descriptions. Currently ELF-only.
private:
   Type *Int8Ty;
   Type *Int32Ty;
 
   bool CompileKernel;
   bool Recover;
 
   Function *HwasanCtorFunction;
 
-  Function *HwasanMemoryAccessCallback[2][kNumberOfAccessSizes];
-  Function *HwasanMemoryAccessCallbackSized[2];
+  FunctionCallee HwasanMemoryAccessCallback[2][kNumberOfAccessSizes];
+  FunctionCallee HwasanMemoryAccessCallbackSized[2];
 
-  Function *HwasanTagMemoryFunc;
-  Function *HwasanGenerateTagFunc;
-  Function *HwasanThreadEnterFunc;
+  FunctionCallee HwasanTagMemoryFunc;
+  FunctionCallee HwasanGenerateTagFunc;
+  FunctionCallee HwasanThreadEnterFunc;
 
   Constant *ShadowGlobal;
 
   Value *LocalDynamicShadow = nullptr;
   GlobalValue *ThreadPtrGlobal = nullptr;
 };
 
 } // end anonymous namespace

 }
 
 void HWAddressSanitizer::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(*C);
   for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
     const std::string TypeStr = AccessIsWrite ? "store" : "load";
     const std::string EndingStr = Recover ? "_noabort" : "";
 
-    HwasanMemoryAccessCallbackSized[AccessIsWrite] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            ClMemoryAccessCallbackPrefix + TypeStr + "N" + EndingStr,
-            FunctionType::get(IRB.getVoidTy(), {IntptrTy, IntptrTy}, false)));
+    HwasanMemoryAccessCallbackSized[AccessIsWrite] = M.getOrInsertFunction(
+        FunctionType::get(IRB.getVoidTy(), {IntptrTy, IntptrTy}, false));
 
     for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
          AccessSizeIndex++) {
       HwasanMemoryAccessCallback[AccessIsWrite][AccessSizeIndex] =
-          checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+          M.getOrInsertFunction(
               ClMemoryAccessCallbackPrefix + TypeStr +
                   itostr(1ULL << AccessSizeIndex) + EndingStr,
-              FunctionType::get(IRB.getVoidTy(), {IntptrTy}, false)));
+              FunctionType::get(IRB.getVoidTy(), {IntptrTy}, false));
     }
   }
 
-  HwasanTagMemoryFunc = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__hwasan_tag_memory", IRB.getVoidTy(), Int8PtrTy, Int8Ty, IntptrTy));
-  HwasanGenerateTagFunc = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("__hwasan_generate_tag", Int8Ty));
+  HwasanTagMemoryFunc = M.getOrInsertFunction(
+      "__hwasan_tag_memory", IRB.getVoidTy(), Int8PtrTy, Int8Ty, IntptrTy);
+  HwasanGenerateTagFunc =
+      M.getOrInsertFunction("__hwasan_generate_tag", Int8Ty);
 
   ShadowGlobal = M.getOrInsertGlobal("__hwasan_shadow",
                                      ArrayType::get(IRB.getInt8Ty(), 0));
 
   const std::string MemIntrinCallbackPrefix =
       CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
-  HWAsanMemmove = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      MemIntrinCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
-      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
-  HWAsanMemcpy = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      MemIntrinCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
-      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy));
-  HWAsanMemset = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      MemIntrinCallbackPrefix + "memset", IRB.getInt8PtrTy(),
-      IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy));
+  HWAsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
+                                        IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+                                        IRB.getInt8PtrTy(), IntptrTy);
+  HWAsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
+                                       IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+                                       IRB.getInt8PtrTy(), IntptrTy);
+  HWAsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
+                                       IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+                                       IRB.getInt32Ty(), IntptrTy);
 
-  HwasanThreadEnterFunc = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("__hwasan_thread_enter", IRB.getVoidTy()));
+  HwasanThreadEnterFunc =
+      M.getOrInsertFunction("__hwasan_thread_enter", IRB.getVoidTy());
 }
 
 Value *HWAddressSanitizer::getDynamicShadowIfunc(IRBuilder<> &IRB) {
   // An empty inline asm with input reg == output reg.
   // An opaque no-op cast, basically.
   InlineAsm *Asm = InlineAsm::get(
       FunctionType::get(Int8PtrTy, {ShadowGlobal->getType()}, false),
       StringRef(""), StringRef("=r,0"),

llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp

bool InstrProfiling::run(Module &M, const TargetLibraryInfo &TLI) {
   emitVNodes();
   emitNameData();
   emitRegistration();
   emitUses();
   emitInitialization();
   return true;
 }
 
-static Constant *getOrInsertValueProfilingCall(Module &M,
-                                               const TargetLibraryInfo &TLI,
-                                               bool IsRange = false) {
+static FunctionCallee
+getOrInsertValueProfilingCall(Module &M, const TargetLibraryInfo &TLI,
   LLVMContext &Ctx = M.getContext();
   auto *ReturnTy = Type::getVoidTy(M.getContext());
 
-  Constant *Res;
+  AttributeList AL;
+  if (auto AK = TLI.getExtAttrForI32Param(false))
+    AL = AL.addParamAttribute(M.getContext(), 2, AK);
+
   if (!IsRange) {
     Type *ParamTypes[] = {
 #define VALUE_PROF_FUNC_PARAM(ParamType, ParamName, ParamLLVMType) ParamLLVMType
 #include "llvm/ProfileData/InstrProfData.inc"
     };
     auto *ValueProfilingCallTy =
         FunctionType::get(ReturnTy, makeArrayRef(ParamTypes), false);
-    Res = M.getOrInsertFunction(getInstrProfValueProfFuncName(),
-                                ValueProfilingCallTy);
+    return M.getOrInsertFunction(getInstrProfValueProfFuncName(),
+                                 ValueProfilingCallTy, AL);
   } else {
     Type *RangeParamTypes[] = {
 #define VALUE_RANGE_PROF 1
 #define VALUE_PROF_FUNC_PARAM(ParamType, ParamName, ParamLLVMType) ParamLLVMType
 #include "llvm/ProfileData/InstrProfData.inc"
 #undef VALUE_RANGE_PROF
     };
     auto *ValueRangeProfilingCallTy =
         FunctionType::get(ReturnTy, makeArrayRef(RangeParamTypes), false);
-    Res = M.getOrInsertFunction(getInstrProfValueRangeProfFuncName(),
-                                ValueRangeProfilingCallTy);
-  }
-
-  if (Function *FunRes = dyn_cast<Function>(Res)) {
-    if (auto AK = TLI.getExtAttrForI32Param(false))
-      FunRes->addParamAttr(2, AK);
+    return M.getOrInsertFunction(getInstrProfValueRangeProfFuncName(),
+                                 ValueRangeProfilingCallTy, AL);
   }
-  return Res;
 }
 
 void InstrProfiling::computeNumValueSiteCounts(InstrProfValueProfileInst *Ind) {
   GlobalVariable *Name = Ind->getName();
   uint64_t ValueKind = Ind->getValueKind()->getZExtValue();
   uint64_t Index = Ind->getIndex()->getZExtValue();
   auto It = ProfileDataMap.find(Name);
   if (It == ProfileDataMap.end()) {

llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp

private:
   /// Thread-local space used to pass origin value to the UMR reporting
   /// function.
   Value *OriginTLS;
 
   /// Are the instrumentation callbacks set up?
   bool CallbacksInitialized = false;
 
   /// The run-time callback to print a warning.
-  Value *WarningFn;
+  FunctionCallee WarningFn;
 
   // These arrays are indexed by log2(AccessSize).
-  Value *MaybeWarningFn[kNumberOfAccessSizes];
-  Value *MaybeStoreOriginFn[kNumberOfAccessSizes];
+  FunctionCallee MaybeWarningFn[kNumberOfAccessSizes];
+  FunctionCallee MaybeStoreOriginFn[kNumberOfAccessSizes];
 
   /// Run-time helper that generates a new origin value for a stack
   /// allocation.
-  Value *MsanSetAllocaOrigin4Fn;
+  FunctionCallee MsanSetAllocaOrigin4Fn;
 
   /// Run-time helper that poisons stack on function entry.
-  Value *MsanPoisonStackFn;
+  FunctionCallee MsanPoisonStackFn;
 
   /// Run-time helper that records a store (or any event) of an
   /// uninitialized value and returns an updated origin id encoding this info.
-  Value *MsanChainOriginFn;
+  FunctionCallee MsanChainOriginFn;
 
   /// MSan runtime replacements for memmove, memcpy and memset.
-  Value *MemmoveFn, *MemcpyFn, *MemsetFn;
+  FunctionCallee MemmoveFn, MemcpyFn, MemsetFn;
 
   /// KMSAN callback for task-local function argument shadow.
-  Value *MsanGetContextStateFn;
+  FunctionCallee MsanGetContextStateFn;
 
   /// Functions for poisoning/unpoisoning local variables
-  Value *MsanPoisonAllocaFn, *MsanUnpoisonAllocaFn;
+  FunctionCallee MsanPoisonAllocaFn, MsanUnpoisonAllocaFn;
 
   /// Each of the MsanMetadataPtrXxx functions returns a pair of shadow/origin
   /// pointers.
-  Value *MsanMetadataPtrForLoadN, *MsanMetadataPtrForStoreN;
-  Value *MsanMetadataPtrForLoad_1_8[4];
-  Value *MsanMetadataPtrForStore_1_8[4];
-  Value *MsanInstrumentAsmStoreFn;
+  FunctionCallee MsanMetadataPtrForLoadN, MsanMetadataPtrForStoreN;
+  FunctionCallee MsanMetadataPtrForLoad_1_8[4];
+  FunctionCallee MsanMetadataPtrForStore_1_8[4];
+  FunctionCallee MsanInstrumentAsmStoreFn;
 
   /// Helper to choose between different MsanMetadataPtrXxx().
-  Value *getKmsanShadowOriginAccessFn(bool isStore, int size);
+  FunctionCallee getKmsanShadowOriginAccessFn(bool isStore, int size);
 
   /// Memory map parameters used in application-to-shadow calculation.
   const MemoryMapParams *MapParams;
 
   /// Custom memory map parameters used when -msan-shadow-base or
   // -msan-origin-base is provided.
   MemoryMapParams CustomMapParams;
 
void MemorySanitizer::initializeCallbacks(Module &M) {
   if (CompileKernel) {
     createKernelApi(M);
   } else {
     createUserspaceApi(M);
   }
   CallbacksInitialized = true;
 }
 
-Value *MemorySanitizer::getKmsanShadowOriginAccessFn(bool isStore, int size) {
-  Value **Fns =
+FunctionCallee MemorySanitizer::getKmsanShadowOriginAccessFn(bool isStore,
+                                                             int size) {
+  FunctionCallee *Fns =
       isStore ? MsanMetadataPtrForStore_1_8 : MsanMetadataPtrForLoad_1_8;
   switch (size) {
   case 1:
     return Fns[0];
   case 2:
     return Fns[1];
   case 4:
     return Fns[2];
void MemorySanitizer::initializeModule(Module &M) {
   if (!CompileKernel) {
     std::tie(MsanCtorFunction, std::ignore) =
         getOrCreateSanitizerCtorAndInitFunctions(
             M, kMsanModuleCtorName, kMsanInitName,
             /*InitArgTypes=*/{},
             /*InitArgs=*/{},
             // This callback is invoked when the functions are created the first
             // time. Hook them into the global ctors list in that case:
-            [&](Function *Ctor, Function *) {
+            [&](Function *Ctor, FunctionCallee) {
               if (!ClWithComdat) {
                 appendToGlobalCtors(M, Ctor, 0);
                 return;
               }
               Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName);
               Ctor->setComdat(MsanCtorComdat);
               appendToGlobalCtors(M, Ctor, 0, Ctor);
             });
if (Shadow->getType()->isAggregateType()) {
                       OriginAlignment);
         return;
       }
 
       unsigned TypeSizeInBits =
           DL.getTypeSizeInBits(ConvertedShadow->getType());
       unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
       if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
-        Value *Fn = MS.MaybeStoreOriginFn[SizeIndex];
+        FunctionCallee Fn = MS.MaybeStoreOriginFn[SizeIndex];
         Value *ConvertedShadow2 = IRB.CreateZExt(
             ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
         IRB.CreateCall(Fn, {ConvertedShadow2,
                             IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
                             Origin});
       } else {
         Value *Cmp = IRB.CreateICmpNE(
             ConvertedShadow, getCleanShadow(ConvertedShadow), "_mscmp");
if (ConstantShadow) {
       return;
     }
 
     const DataLayout &DL = OrigIns->getModule()->getDataLayout();
 
     unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType());
     unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
     if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
-      Value *Fn = MS.MaybeWarningFn[SizeIndex];
+      FunctionCallee Fn = MS.MaybeWarningFn[SizeIndex];
       Value *ConvertedShadow2 =
           IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
       IRB.CreateCall(Fn, {ConvertedShadow2, MS.TrackOrigins && Origin
                                                 ? Origin
                                                 : (Value *)IRB.getInt32(0)});
     } else {
       Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
                                     getCleanShadow(ConvertedShadow), "_mscmp");
struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
 
   std::pair<Value *, Value *>
   getShadowOriginPtrKernel(Value *Addr, IRBuilder<> &IRB, Type *ShadowTy,
                            unsigned Alignment, bool isStore) {
     Value *ShadowOriginPtrs;
     const DataLayout &DL = F.getParent()->getDataLayout();
     int Size = DL.getTypeStoreSize(ShadowTy);
 
-    Value *Getter = MS.getKmsanShadowOriginAccessFn(isStore, Size);
+    FunctionCallee Getter = MS.getKmsanShadowOriginAccessFn(isStore, Size);
     Value *AddrCast =
         IRB.CreatePointerCast(Addr, PointerType::get(IRB.getInt8Ty(), 0));
     if (Getter) {
       ShadowOriginPtrs = IRB.CreateCall(Getter, AddrCast);
     } else {
       Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size);
       ShadowOriginPtrs = IRB.CreateCall(isStore ? MS.MsanMetadataPtrForStoreN
                                                 : MS.MsanMetadataPtrForLoadN,

llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp

private:
   void SetNoSanitizeMetadata(Instruction *I) {
     I->setMetadata(I->getModule()->getMDKindID("nosanitize"),
                    MDNode::get(*C, None));
   }
 
   std::string getSectionName(const std::string &Section) const;
   std::string getSectionStart(const std::string &Section) const;
   std::string getSectionEnd(const std::string &Section) const;
-  Function *SanCovTracePCIndir;
-  Function *SanCovTracePC, *SanCovTracePCGuard;
-  Function *SanCovTraceCmpFunction[4];
-  Function *SanCovTraceConstCmpFunction[4];
-  Function *SanCovTraceDivFunction[2];
-  Function *SanCovTraceGepFunction;
-  Function *SanCovTraceSwitchFunction;
+  FunctionCallee SanCovTracePCIndir;
+  FunctionCallee SanCovTracePC, SanCovTracePCGuard;
+  FunctionCallee SanCovTraceCmpFunction[4];
+  FunctionCallee SanCovTraceConstCmpFunction[4];
+  FunctionCallee SanCovTraceDivFunction[2];
+  FunctionCallee SanCovTraceGepFunction;
+  FunctionCallee SanCovTraceSwitchFunction;
   GlobalVariable *SanCovLowestStack;
   InlineAsm *EmptyAsm;
   Type *IntptrTy, *IntptrPtrTy, *Int64Ty, *Int64PtrTy, *Int32Ty, *Int32PtrTy,
       *Int16Ty, *Int8Ty, *Int8PtrTy;
   Module *CurModule;
   std::string CurModuleUniqueId;
   Triple TargetTriple;
   LLVMContext *C;
bool SanitizerCoverageModule::runOnModule(Module &M) {
   Int64PtrTy = PointerType::getUnqual(IRB.getInt64Ty());
   Int32PtrTy = PointerType::getUnqual(IRB.getInt32Ty());
   Int8PtrTy = PointerType::getUnqual(IRB.getInt8Ty());
   Int64Ty = IRB.getInt64Ty();
   Int32Ty = IRB.getInt32Ty();
   Int16Ty = IRB.getInt16Ty();
   Int8Ty = IRB.getInt8Ty();
 
-  SanCovTracePCIndir = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy));
+  SanCovTracePCIndir =
+      M.getOrInsertFunction(SanCovTracePCIndirName, VoidTy, IntptrTy);
+  // Make sure smaller parameters are zero-extended to i64 as required by the
+  // x86_64 ABI.
+  AttributeList SanCovTraceCmpZeroExtAL;
+  if (TargetTriple.getArch() == Triple::x86_64) {
+    SanCovTraceCmpZeroExtAL =
+        SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 0, Attribute::ZExt);
+    SanCovTraceCmpZeroExtAL =
+        SanCovTraceCmpZeroExtAL.addParamAttribute(*C, 1, Attribute::ZExt);
+  }
+
   SanCovTraceCmpFunction[0] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceCmp1, VoidTy, IRB.getInt8Ty(), IRB.getInt8Ty()));
-  SanCovTraceCmpFunction[1] = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(SanCovTraceCmp2, VoidTy, IRB.getInt16Ty(),
-                            IRB.getInt16Ty()));
-  SanCovTraceCmpFunction[2] = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(SanCovTraceCmp4, VoidTy, IRB.getInt32Ty(),
-                            IRB.getInt32Ty()));
+      M.getOrInsertFunction(SanCovTraceCmp1, SanCovTraceCmpZeroExtAL, VoidTy,
+                            IRB.getInt8Ty(), IRB.getInt8Ty());
+  SanCovTraceCmpFunction[1] =
+      M.getOrInsertFunction(SanCovTraceCmp2, SanCovTraceCmpZeroExtAL, VoidTy,
+                            IRB.getInt16Ty(), IRB.getInt16Ty());
+  SanCovTraceCmpFunction[2] =
+      M.getOrInsertFunction(SanCovTraceCmp4, SanCovTraceCmpZeroExtAL, VoidTy,
+                            IRB.getInt32Ty(), IRB.getInt32Ty());
   SanCovTraceCmpFunction[3] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty));
+      M.getOrInsertFunction(SanCovTraceCmp8, VoidTy, Int64Ty, Int64Ty);
 
-  SanCovTraceConstCmpFunction[0] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceConstCmp1, VoidTy, Int8Ty, Int8Ty));
-  SanCovTraceConstCmpFunction[1] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceConstCmp2, VoidTy, Int16Ty, Int16Ty));
-  SanCovTraceConstCmpFunction[2] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceConstCmp4, VoidTy, Int32Ty, Int32Ty));
+  SanCovTraceConstCmpFunction[0] = M.getOrInsertFunction(
+      SanCovTraceConstCmp1, SanCovTraceCmpZeroExtAL, VoidTy, Int8Ty, Int8Ty);
+  SanCovTraceConstCmpFunction[1] = M.getOrInsertFunction(
+      SanCovTraceConstCmp2, SanCovTraceCmpZeroExtAL, VoidTy, Int16Ty, Int16Ty);
+  SanCovTraceConstCmpFunction[2] = M.getOrInsertFunction(
+      SanCovTraceConstCmp4, SanCovTraceCmpZeroExtAL, VoidTy, Int32Ty, Int32Ty);
   SanCovTraceConstCmpFunction[3] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty));
+      M.getOrInsertFunction(SanCovTraceConstCmp8, VoidTy, Int64Ty, Int64Ty);
 
+  {
+    AttributeList AL;
+    if (TargetTriple.getArch() == Triple::x86_64)
+      AL = AL.addParamAttribute(*C, 0, Attribute::ZExt);
     SanCovTraceDivFunction[0] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceDiv4, VoidTy, IRB.getInt32Ty()));
+        M.getOrInsertFunction(SanCovTraceDiv4, AL, VoidTy, IRB.getInt32Ty());
+  }
   SanCovTraceDivFunction[1] =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceDiv8, VoidTy, Int64Ty));
+      M.getOrInsertFunction(SanCovTraceDiv8, VoidTy, Int64Ty);
   SanCovTraceGepFunction =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceGep, VoidTy, IntptrTy));
+      M.getOrInsertFunction(SanCovTraceGep, VoidTy, IntptrTy);
   SanCovTraceSwitchFunction =
-      checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-          SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy));
+      M.getOrInsertFunction(SanCovTraceSwitchName, VoidTy, Int64Ty, Int64PtrTy);
 
   Constant *SanCovLowestStackConstant =
       M.getOrInsertGlobal(SanCovLowestStackName, IntptrTy);
   SanCovLowestStack = cast<GlobalVariable>(SanCovLowestStackConstant);
   SanCovLowestStack->setThreadLocalMode(
       GlobalValue::ThreadLocalMode::InitialExecTLSModel);
   if (Options.StackDepth && !SanCovLowestStack->isDeclaration())
     SanCovLowestStack->setInitializer(Constant::getAllOnesValue(IntptrTy));
 
-  // Make sure smaller parameters are zero-extended to i64 as required by the
-  // x86_64 ABI.
-  if (TargetTriple.getArch() == Triple::x86_64) {
-    for (int i = 0; i < 3; i++) {
-      SanCovTraceCmpFunction[i]->addParamAttr(0, Attribute::ZExt);
-      SanCovTraceCmpFunction[i]->addParamAttr(1, Attribute::ZExt);
-      SanCovTraceConstCmpFunction[i]->addParamAttr(0, Attribute::ZExt);
-      SanCovTraceConstCmpFunction[i]->addParamAttr(1, Attribute::ZExt);
-    }
-    SanCovTraceDivFunction[0]->addParamAttr(0, Attribute::ZExt);
-  }
-
-
   // We insert an empty inline asm after cov callbacks to avoid callback merge.
   EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
                             StringRef(""), StringRef(""),
                             /*hasSideEffects=*/true);
 
-  SanCovTracePC = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction(SanCovTracePCName, VoidTy));
-  SanCovTracePCGuard = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      SanCovTracePCGuardName, VoidTy, Int32PtrTy));
+  SanCovTracePC = M.getOrInsertFunction(SanCovTracePCName, VoidTy);
+  SanCovTracePCGuard =
+      M.getOrInsertFunction(SanCovTracePCGuardName, VoidTy, Int32PtrTy);
 
   for (auto &F : M)
     runOnFunction(F);
 
   Function *Ctor = nullptr;
 
   if (FunctionGuardArray)
     Ctor = CreateInitCallsForSections(M, SanCovTracePCGuardInitName, Int32PtrTy,
                                       SanCovGuardsSectionName);
   if (Function8bitCounterArray)
     Ctor = CreateInitCallsForSections(M, SanCov8bitCountersInitName, Int8PtrTy,
                                       SanCovCountersSectionName);
   if (Ctor && Options.PCTable) {
     auto SecStartEnd = CreateSecStartEnd(M, SanCovPCsSectionName, IntptrPtrTy);
-    Function *InitFunction = declareSanitizerInitFunction(
+    FunctionCallee InitFunction = declareSanitizerInitFunction(
         M, SanCovPCsInitName, {IntptrPtrTy, IntptrPtrTy});
     IRBuilder<> IRBCtor(Ctor->getEntryBlock().getTerminator());
     IRBCtor.CreateCall(InitFunction, {SecStartEnd.first, SecStartEnd.second});
   }
   // We don't reference these arrays directly in any of our runtime functions,
   // so we need to prevent them from being dead stripped.
   if (TargetTriple.isOSBinFormatMachO())
     appendToUsed(M, GlobalsToAppendToUsed);

llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp

void chooseInstructionsToInstrument(SmallVectorImpl<Instruction *> &Local,
                                       const DataLayout &DL);
   bool addrPointsToConstantData(Value *Addr);
   int getMemoryAccessFuncIndex(Value *Addr, const DataLayout &DL);
   void InsertRuntimeIgnores(Function &F);
 
   Type *IntptrTy;
   IntegerType *OrdTy;
   // Callbacks to run-time library are computed in doInitialization.
-  Function *TsanFuncEntry;
-  Function *TsanFuncExit;
-  Function *TsanIgnoreBegin;
-  Function *TsanIgnoreEnd;
+  FunctionCallee TsanFuncEntry;
+  FunctionCallee TsanFuncExit;
+  FunctionCallee TsanIgnoreBegin;
+  FunctionCallee TsanIgnoreEnd;
   // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
   static const size_t kNumberOfAccessSizes = 5;
-  Function *TsanRead[kNumberOfAccessSizes];
-  Function *TsanWrite[kNumberOfAccessSizes];
-  Function *TsanUnalignedRead[kNumberOfAccessSizes];
-  Function *TsanUnalignedWrite[kNumberOfAccessSizes];
-  Function *TsanAtomicLoad[kNumberOfAccessSizes];
-  Function *TsanAtomicStore[kNumberOfAccessSizes];
-  Function *TsanAtomicRMW[AtomicRMWInst::LAST_BINOP + 1][kNumberOfAccessSizes];
-  Function *TsanAtomicCAS[kNumberOfAccessSizes];
-  Function *TsanAtomicThreadFence;
-  Function *TsanAtomicSignalFence;
-  Function *TsanVptrUpdate;
-  Function *TsanVptrLoad;
-  Function *MemmoveFn, *MemcpyFn, *MemsetFn;
+  FunctionCallee TsanRead[kNumberOfAccessSizes];
+  FunctionCallee TsanWrite[kNumberOfAccessSizes];
+  FunctionCallee TsanUnalignedRead[kNumberOfAccessSizes];
+  FunctionCallee TsanUnalignedWrite[kNumberOfAccessSizes];
+  FunctionCallee TsanAtomicLoad[kNumberOfAccessSizes];
+  FunctionCallee TsanAtomicStore[kNumberOfAccessSizes];
+  FunctionCallee TsanAtomicRMW[AtomicRMWInst::LAST_BINOP + 1]
+                              [kNumberOfAccessSizes];
+  FunctionCallee TsanAtomicCAS[kNumberOfAccessSizes];
+  FunctionCallee TsanAtomicThreadFence;
+  FunctionCallee TsanAtomicSignalFence;
+  FunctionCallee TsanVptrUpdate;
+  FunctionCallee TsanVptrLoad;
+  FunctionCallee MemmoveFn, MemcpyFn, MemsetFn;
   Function *TsanCtorFunction;
 };
 
 struct ThreadSanitizerLegacyPass : FunctionPass {
   ThreadSanitizerLegacyPass() : FunctionPass(ID) {}
   StringRef getPassName() const override;
   void getAnalysisUsage(AnalysisUsage &AU) const override;
   bool runOnFunction(Function &F) override;

 }
 
 void ThreadSanitizer::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(M.getContext());
   AttributeList Attr;
   Attr = Attr.addAttribute(M.getContext(), AttributeList::FunctionIndex,
                            Attribute::NoUnwind);
   // Initialize the callbacks.
-  TsanFuncEntry = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__tsan_func_entry", Attr, IRB.getVoidTy(), IRB.getInt8PtrTy()));
-  TsanFuncExit = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("__tsan_func_exit", Attr, IRB.getVoidTy()));
-  TsanIgnoreBegin = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__tsan_ignore_thread_begin", Attr, IRB.getVoidTy()));
-  TsanIgnoreEnd = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__tsan_ignore_thread_end", Attr, IRB.getVoidTy()));
+  TsanFuncEntry = M.getOrInsertFunction("__tsan_func_entry", Attr,
+                                        IRB.getVoidTy(), IRB.getInt8PtrTy());
+  TsanFuncExit =
+      M.getOrInsertFunction("__tsan_func_exit", Attr, IRB.getVoidTy());
+  TsanIgnoreBegin = M.getOrInsertFunction("__tsan_ignore_thread_begin", Attr,
+                                          IRB.getVoidTy());
+  TsanIgnoreEnd =
+      M.getOrInsertFunction("__tsan_ignore_thread_end", Attr, IRB.getVoidTy());
   OrdTy = IRB.getInt32Ty();
   for (size_t i = 0; i < kNumberOfAccessSizes; ++i) {
     const unsigned ByteSize = 1U << i;
     const unsigned BitSize = ByteSize * 8;
     std::string ByteSizeStr = utostr(ByteSize);
     std::string BitSizeStr = utostr(BitSize);
     SmallString<32> ReadName("__tsan_read" + ByteSizeStr);
-    TsanRead[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-        ReadName, Attr, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    TsanRead[i] = M.getOrInsertFunction(ReadName, Attr, IRB.getVoidTy(),
+                                        IRB.getInt8PtrTy());
 
     SmallString<32> WriteName("__tsan_write" + ByteSizeStr);
-    TsanWrite[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-        WriteName, Attr, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    TsanWrite[i] = M.getOrInsertFunction(WriteName, Attr, IRB.getVoidTy(),
+                                         IRB.getInt8PtrTy());
 
     SmallString<64> UnalignedReadName("__tsan_unaligned_read" + ByteSizeStr);
-    TsanUnalignedRead[i] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            UnalignedReadName, Attr, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    TsanUnalignedRead[i] = M.getOrInsertFunction(
+        UnalignedReadName, Attr, IRB.getVoidTy(), IRB.getInt8PtrTy());
 
     SmallString<64> UnalignedWriteName("__tsan_unaligned_write" + ByteSizeStr);
-    TsanUnalignedWrite[i] =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            UnalignedWriteName, Attr, IRB.getVoidTy(), IRB.getInt8PtrTy()));
+    TsanUnalignedWrite[i] = M.getOrInsertFunction(
+        UnalignedWriteName, Attr, IRB.getVoidTy(), IRB.getInt8PtrTy());
 
     Type *Ty = Type::getIntNTy(M.getContext(), BitSize);
     Type *PtrTy = Ty->getPointerTo();
     SmallString<32> AtomicLoadName("__tsan_atomic" + BitSizeStr + "_load");
-    TsanAtomicLoad[i] = checkSanitizerInterfaceFunction(
-        M.getOrInsertFunction(AtomicLoadName, Attr, Ty, PtrTy, OrdTy));
+    TsanAtomicLoad[i] =
+        M.getOrInsertFunction(AtomicLoadName, Attr, Ty, PtrTy, OrdTy);
 
     SmallString<32> AtomicStoreName("__tsan_atomic" + BitSizeStr + "_store");
-    TsanAtomicStore[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-        AtomicStoreName, Attr, IRB.getVoidTy(), PtrTy, Ty, OrdTy));
+    TsanAtomicStore[i] = M.getOrInsertFunction(
+        AtomicStoreName, Attr, IRB.getVoidTy(), PtrTy, Ty, OrdTy);
 
     for (int op = AtomicRMWInst::FIRST_BINOP;
         op <= AtomicRMWInst::LAST_BINOP; ++op) {
       TsanAtomicRMW[op][i] = nullptr;
       const char *NamePart = nullptr;
       if (op == AtomicRMWInst::Xchg)
         NamePart = "_exchange";
       else if (op == AtomicRMWInst::Add)
         NamePart = "_fetch_add";
       else if (op == AtomicRMWInst::Sub)
         NamePart = "_fetch_sub";
       else if (op == AtomicRMWInst::And)
         NamePart = "_fetch_and";
       else if (op == AtomicRMWInst::Or)
         NamePart = "_fetch_or";
       else if (op == AtomicRMWInst::Xor)
         NamePart = "_fetch_xor";
       else if (op == AtomicRMWInst::Nand)
         NamePart = "_fetch_nand";
       else
         continue;
       SmallString<32> RMWName("__tsan_atomic" + itostr(BitSize) + NamePart);
-      TsanAtomicRMW[op][i] = checkSanitizerInterfaceFunction(
-          M.getOrInsertFunction(RMWName, Attr, Ty, PtrTy, Ty, OrdTy));
+      TsanAtomicRMW[op][i] =
+          M.getOrInsertFunction(RMWName, Attr, Ty, PtrTy, Ty, OrdTy);
     }
 
     SmallString<32> AtomicCASName("__tsan_atomic" + BitSizeStr +
                                   "_compare_exchange_val");
-    TsanAtomicCAS[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-        AtomicCASName, Attr, Ty, PtrTy, Ty, Ty, OrdTy, OrdTy));
+    TsanAtomicCAS[i] = M.getOrInsertFunction(AtomicCASName, Attr, Ty, PtrTy, Ty,
+                                             Ty, OrdTy, OrdTy);
   }
-  TsanVptrUpdate = checkSanitizerInterfaceFunction(
+  TsanVptrUpdate =
       M.getOrInsertFunction("__tsan_vptr_update", Attr, IRB.getVoidTy(),
-                            IRB.getInt8PtrTy(), IRB.getInt8PtrTy()));
-  TsanVptrLoad = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__tsan_vptr_read", Attr, IRB.getVoidTy(), IRB.getInt8PtrTy()));
-  TsanAtomicThreadFence = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__tsan_atomic_thread_fence", Attr, IRB.getVoidTy(), OrdTy));
-  TsanAtomicSignalFence = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      "__tsan_atomic_signal_fence", Attr, IRB.getVoidTy(), OrdTy));
-
-  MemmoveFn = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("memmove", Attr, IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
-                            IRB.getInt8PtrTy(), IntptrTy));
-  MemcpyFn = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("memcpy", Attr, IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
-                            IRB.getInt8PtrTy(), IntptrTy));
-  MemsetFn = checkSanitizerInterfaceFunction(
-      M.getOrInsertFunction("memset", Attr, IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
-                            IRB.getInt32Ty(), IntptrTy));
+                            IRB.getInt8PtrTy(), IRB.getInt8PtrTy());
+  TsanVptrLoad = M.getOrInsertFunction("__tsan_vptr_read", Attr,
+                                       IRB.getVoidTy(), IRB.getInt8PtrTy());
+  TsanAtomicThreadFence = M.getOrInsertFunction("__tsan_atomic_thread_fence",
+                                                Attr, IRB.getVoidTy(), OrdTy);
+  TsanAtomicSignalFence = M.getOrInsertFunction("__tsan_atomic_signal_fence",
+                                                Attr, IRB.getVoidTy(), OrdTy);
+
+  MemmoveFn =
+      M.getOrInsertFunction("memmove", Attr, IRB.getInt8PtrTy(),
+                            IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy);
+  MemcpyFn =
+      M.getOrInsertFunction("memcpy", Attr, IRB.getInt8PtrTy(),
+                            IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy);
+  MemsetFn =
+      M.getOrInsertFunction("memset", Attr, IRB.getInt8PtrTy(),
+                            IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy);
 }
 
 ThreadSanitizer::ThreadSanitizer(Module &M) {
   const DataLayout &DL = M.getDataLayout();
   IntptrTy = DL.getIntPtrType(M.getContext());
   std::tie(TsanCtorFunction, std::ignore) =
       getOrCreateSanitizerCtorAndInitFunctions(
           M, kTsanModuleCtorName, kTsanInitName, /*InitArgTypes=*/{},
           /*InitArgs=*/{},
           // This callback is invoked when the functions are created the first
           // time. Hook them into the global ctors list in that case:
-          [&](Function *Ctor, Function *) { appendToGlobalCtors(M, Ctor, 0); });
+          [&](Function *Ctor, FunctionCallee) {
+            appendToGlobalCtors(M, Ctor, 0);
+          });
 }
 
 static bool isVtableAccess(Instruction *I) {
   if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
     return Tag->isTBAAVtableAccess();
   return false;
 }
 
if (!IsWrite && isVtableAccess(I)) {
     NumInstrumentedVtableReads++;
     return true;
   }
   const unsigned Alignment = IsWrite
       ? cast<StoreInst>(I)->getAlignment()
       : cast<LoadInst>(I)->getAlignment();
   Type *OrigTy = cast<PointerType>(Addr->getType())->getElementType();
   const uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
-  Value *OnAccessFunc = nullptr;
+  FunctionCallee OnAccessFunc = nullptr;
   if (Alignment == 0 || Alignment >= 8 || (Alignment % (TypeSize / 8)) == 0)
     OnAccessFunc = IsWrite ? TsanWrite[Idx] : TsanRead[Idx];
   else
     OnAccessFunc = IsWrite ? TsanUnalignedWrite[Idx] : TsanUnalignedRead[Idx];
   IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
   if (IsWrite) NumInstrumentedWrites++;
   else         NumInstrumentedReads++;
   return true;
Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
                      createOrdering(&IRB, SI->getOrdering())};
     CallInst *C = CallInst::Create(TsanAtomicStore[Idx], Args);
     ReplaceInstWithInst(I, C);
   } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) {
     Value *Addr = RMWI->getPointerOperand();
     int Idx = getMemoryAccessFuncIndex(Addr, DL);
     if (Idx < 0)
       return false;
-    Function *F = TsanAtomicRMW[RMWI->getOperation()][Idx];
+    FunctionCallee F = TsanAtomicRMW[RMWI->getOperation()][Idx];
     if (!F)
       return false;
     const unsigned ByteSize = 1U << Idx;
     const unsigned BitSize = ByteSize * 8;
     Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
     Type *PtrTy = Ty->getPointerTo();
     Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
                      IRB.CreateIntCast(RMWI->getValOperand(), Ty, false),
if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
     Value *Res =
       IRB.CreateInsertValue(UndefValue::get(CASI->getType()), OldVal, 0);
     Res = IRB.CreateInsertValue(Res, Success, 1);
 
     I->replaceAllUsesWith(Res);
     I->eraseFromParent();
   } else if (FenceInst *FI = dyn_cast<FenceInst>(I)) {
     Value *Args[] = {createOrdering(&IRB, FI->getOrdering())};
-    Function *F = FI->getSyncScopeID() == SyncScope::SingleThread ?
-        TsanAtomicSignalFence : TsanAtomicThreadFence;
+    FunctionCallee F = FI->getSyncScopeID() == SyncScope::SingleThread
+                           ? TsanAtomicSignalFence
+                           : TsanAtomicThreadFence;
     CallInst *C = CallInst::Create(F, Args);
     ReplaceInstWithInst(I, C);
   }
   return true;
 }
 
 int ThreadSanitizer::getMemoryAccessFuncIndex(Value *Addr,
                                               const DataLayout &DL) {

llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

if (SplatValue) {
     NewCall =
         Builder.CreateMemSet(BasePtr, SplatValue, NumBytes, StoreAlignment);
   } else {
     // Everything is emitted in default address space
     Type *Int8PtrTy = DestInt8PtrTy;
 
     Module *M = TheStore->getModule();
     StringRef FuncName = "memset_pattern16";
-    Value *MSP =
-        M->getOrInsertFunction(FuncName, Builder.getVoidTy(),
+    FunctionCallee MSP = M->getOrInsertFunction(FuncName, Builder.getVoidTy(),
                                                 Int8PtrTy, Int8PtrTy, IntPtr);
     inferLibFuncAttributes(M, FuncName, *TLI);
 
     // Otherwise we should form a memset_pattern16.  PatternValue is known to be
     // an constant array of 16-bytes.  Plop the value into a mergable global.
     GlobalVariable *GV = new GlobalVariable(*M, PatternValue->getType(), true,
                                             GlobalValue::PrivateLinkage,
                                             PatternValue, ".memset_pattern");
     GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global); // Ok to merge these.

llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp

if (F->getIntrinsicID() == Intrinsic::experimental_deoptimize) {
         DomainTy.push_back(Arg->getType());
       auto *FTy = FunctionType::get(Type::getVoidTy(F->getContext()), DomainTy,
                                     /* isVarArg = */ false);
 
       // Note: CallTarget can be a bitcast instruction of a symbol if there are
       // calls to @llvm.experimental.deoptimize with different argument types in
       // the same module.  This is fine -- we assume the frontend knew what it
       // was doing when generating this kind of IR.
-      CallTarget =
-          F->getParent()->getOrInsertFunction("__llvm_deoptimize", FTy);
+      CallTarget = F->getParent()
+                       ->getOrInsertFunction("__llvm_deoptimize", FTy)
+                       .getCallee();
 
       IsDeoptimize = true;
     }
   }
 
   // Create the statepoint given all the arguments
   Instruction *Token = nullptr;
   if (CS.isCall()) {

 static void insertUseHolderAfter(CallSite &CS, const ArrayRef<Value *> Values,
                                  SmallVectorImpl<CallInst *> &Holders) {
   if (Values.empty())
     // No values to hold live, might as well not insert the empty holder
     return;
 
   Module *M = CS.getInstruction()->getModule();
   // Use a dummy vararg function to actually hold the values live
-  Function *Func = cast<Function>(M->getOrInsertFunction(
-      "__tmp_use", FunctionType::get(Type::getVoidTy(M->getContext()), true)));
+  FunctionCallee Func = M->getOrInsertFunction(
+      "__tmp_use", FunctionType::get(Type::getVoidTy(M->getContext()), true));
   if (CS.isCall()) {
     // For call safepoints insert dummy calls right after safepoint
     Holders.push_back(CallInst::Create(Func, Values, "",
                                        &*++CS.getInstruction()->getIterator()));
     return;
   }
   // For invoke safepooints insert dummy calls both in normal and
   // exceptional destination blocks

llvm/lib/Transforms/Utils/BuildLibCalls.cpp

 Value *llvm::emitStrLen(Value *Ptr, IRBuilder<> &B, const DataLayout &DL,
                         const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_strlen))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef StrlenName = TLI->getName(LibFunc_strlen);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
-  Constant *StrLen = M->getOrInsertFunction(StrlenName, DL.getIntPtrType(Context),
-                                            B.getInt8PtrTy());
+  FunctionCallee StrLen = M->getOrInsertFunction(
+      StrlenName, DL.getIntPtrType(Context), B.getInt8PtrTy());
   inferLibFuncAttributes(M, StrlenName, *TLI);
   CallInst *CI = B.CreateCall(StrLen, castToCStr(Ptr, B), StrlenName);
-  if (const Function *F = dyn_cast<Function>(StrLen->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(StrLen.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitStrChr(Value *Ptr, char C, IRBuilder<> &B,
                         const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_strchr))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef StrChrName = TLI->getName(LibFunc_strchr);
   Type *I8Ptr = B.getInt8PtrTy();
   Type *I32Ty = B.getInt32Ty();
-  Constant *StrChr =
+  FunctionCallee StrChr =
       M->getOrInsertFunction(StrChrName, I8Ptr, I8Ptr, I32Ty);
   inferLibFuncAttributes(M, StrChrName, *TLI);
   CallInst *CI = B.CreateCall(
       StrChr, {castToCStr(Ptr, B), ConstantInt::get(I32Ty, C)}, StrChrName);
-  if (const Function *F = dyn_cast<Function>(StrChr->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(StrChr.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitStrNCmp(Value *Ptr1, Value *Ptr2, Value *Len, IRBuilder<> &B,
                          const DataLayout &DL, const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_strncmp))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef StrNCmpName = TLI->getName(LibFunc_strncmp);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
-  Value *StrNCmp = M->getOrInsertFunction(StrNCmpName, B.getInt32Ty(),
-                                          B.getInt8PtrTy(), B.getInt8PtrTy(),
-                                          DL.getIntPtrType(Context));
+  FunctionCallee StrNCmp =
+      M->getOrInsertFunction(StrNCmpName, B.getInt32Ty(), B.getInt8PtrTy(),
+                             B.getInt8PtrTy(), DL.getIntPtrType(Context));
   inferLibFuncAttributes(M, StrNCmpName, *TLI);
   CallInst *CI = B.CreateCall(
       StrNCmp, {castToCStr(Ptr1, B), castToCStr(Ptr2, B), Len}, StrNCmpName);
 
-  if (const Function *F = dyn_cast<Function>(StrNCmp->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(StrNCmp.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitStrCpy(Value *Dst, Value *Src, IRBuilder<> &B,
                         const TargetLibraryInfo *TLI, StringRef Name) {
   if (!TLI->has(LibFunc_strcpy))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   Type *I8Ptr = B.getInt8PtrTy();
-  Value *StrCpy = M->getOrInsertFunction(Name, I8Ptr, I8Ptr, I8Ptr);
+  FunctionCallee StrCpy = M->getOrInsertFunction(Name, I8Ptr, I8Ptr, I8Ptr);
   inferLibFuncAttributes(M, Name, *TLI);
   CallInst *CI =
       B.CreateCall(StrCpy, {castToCStr(Dst, B), castToCStr(Src, B)}, Name);
-  if (const Function *F = dyn_cast<Function>(StrCpy->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(StrCpy.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitStrNCpy(Value *Dst, Value *Src, Value *Len, IRBuilder<> &B,
                          const TargetLibraryInfo *TLI, StringRef Name) {
   if (!TLI->has(LibFunc_strncpy))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   Type *I8Ptr = B.getInt8PtrTy();
-  Value *StrNCpy = M->getOrInsertFunction(Name, I8Ptr, I8Ptr, I8Ptr,
-                                          Len->getType());
+  FunctionCallee StrNCpy =
+      M->getOrInsertFunction(Name, I8Ptr, I8Ptr, I8Ptr, Len->getType());
   inferLibFuncAttributes(M, Name, *TLI);
   CallInst *CI = B.CreateCall(
       StrNCpy, {castToCStr(Dst, B), castToCStr(Src, B), Len}, Name);
-  if (const Function *F = dyn_cast<Function>(StrNCpy->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(StrNCpy.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitMemCpyChk(Value *Dst, Value *Src, Value *Len, Value *ObjSize,
                            IRBuilder<> &B, const DataLayout &DL,
                            const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_memcpy_chk))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   AttributeList AS;
   AS = AttributeList::get(M->getContext(), AttributeList::FunctionIndex,
                           Attribute::NoUnwind);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
-  Value *MemCpy = M->getOrInsertFunction(
+  FunctionCallee MemCpy = M->getOrInsertFunction(
       "__memcpy_chk", AttributeList::get(M->getContext(), AS), B.getInt8PtrTy(),
       B.getInt8PtrTy(), B.getInt8PtrTy(), DL.getIntPtrType(Context),
       DL.getIntPtrType(Context));
   Dst = castToCStr(Dst, B);
   Src = castToCStr(Src, B);
   CallInst *CI = B.CreateCall(MemCpy, {Dst, Src, Len, ObjSize});
-  if (const Function *F = dyn_cast<Function>(MemCpy->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(MemCpy.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitMemChr(Value *Ptr, Value *Val, Value *Len, IRBuilder<> &B,
                         const DataLayout &DL, const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_memchr))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef MemChrName = TLI->getName(LibFunc_memchr);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
-  Value *MemChr = M->getOrInsertFunction(MemChrName, B.getInt8PtrTy(),
-                                         B.getInt8PtrTy(), B.getInt32Ty(),
-                                         DL.getIntPtrType(Context));
+  FunctionCallee MemChr =
+      M->getOrInsertFunction(MemChrName, B.getInt8PtrTy(), B.getInt8PtrTy(),
+                             B.getInt32Ty(), DL.getIntPtrType(Context));
   inferLibFuncAttributes(M, MemChrName, *TLI);
   CallInst *CI = B.CreateCall(MemChr, {castToCStr(Ptr, B), Val, Len}, MemChrName);
 
-  if (const Function *F = dyn_cast<Function>(MemChr->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(MemChr.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitMemCmp(Value *Ptr1, Value *Ptr2, Value *Len, IRBuilder<> &B,
                         const DataLayout &DL, const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_memcmp))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef MemCmpName = TLI->getName(LibFunc_memcmp);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
-  Value *MemCmp = M->getOrInsertFunction(MemCmpName, B.getInt32Ty(),
-                                         B.getInt8PtrTy(), B.getInt8PtrTy(),
-                                         DL.getIntPtrType(Context));
+  FunctionCallee MemCmp =
+      M->getOrInsertFunction(MemCmpName, B.getInt32Ty(), B.getInt8PtrTy(),
+                             B.getInt8PtrTy(), DL.getIntPtrType(Context));
   inferLibFuncAttributes(M, MemCmpName, *TLI);
   CallInst *CI = B.CreateCall(
       MemCmp, {castToCStr(Ptr1, B), castToCStr(Ptr2, B), Len}, MemCmpName);
 
-  if (const Function *F = dyn_cast<Function>(MemCmp->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(MemCmp.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 /// Append a suffix to the function name according to the type of 'Op'.
 static void appendTypeSuffix(Value *Op, StringRef &Name,
                              SmallString<20> &NameBuffer) {

 }
 
 static Value *emitUnaryFloatFnCallHelper(Value *Op, StringRef Name,
                                          IRBuilder<> &B,
                                          const AttributeList &Attrs) {
   assert((Name != "") && "Must specify Name to emitUnaryFloatFnCall");
 
   Module *M = B.GetInsertBlock()->getModule();
-  Value *Callee = M->getOrInsertFunction(Name, Op->getType(),
-                                         Op->getType());
+  FunctionCallee Callee =
+      M->getOrInsertFunction(Name, Op->getType(), Op->getType());
   CallInst *CI = B.CreateCall(Callee, Op, Name);
 
   // The incoming attribute set may have come from a speculatable intrinsic, but
   // is being replaced with a library call which is not allowed to be
   // speculatable.
   CI->setAttributes(Attrs.removeAttribute(B.getContext(),
                                           AttributeList::FunctionIndex,
                                           Attribute::Speculatable));
-  if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(Callee.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitUnaryFloatFnCall(Value *Op, StringRef Name, IRBuilder<> &B,
                                   const AttributeList &Attrs) {
   SmallString<20> NameBuffer;

 Value *llvm::emitBinaryFloatFnCall(Value *Op1, Value *Op2, StringRef Name,
                                    IRBuilder<> &B, const AttributeList &Attrs) {
   assert((Name != "") && "Must specify Name to emitBinaryFloatFnCall");
 
   SmallString<20> NameBuffer;
   appendTypeSuffix(Op1, Name, NameBuffer);
 
   Module *M = B.GetInsertBlock()->getModule();
-  Value *Callee = M->getOrInsertFunction(Name, Op1->getType(), Op1->getType(),
-                                         Op2->getType());
+  FunctionCallee Callee = M->getOrInsertFunction(
+      Name, Op1->getType(), Op1->getType(), Op2->getType());
   CallInst *CI = B.CreateCall(Callee, {Op1, Op2}, Name);
   CI->setAttributes(Attrs);
-  if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(Callee.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitPutChar(Value *Char, IRBuilder<> &B,
                          const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_putchar))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef PutCharName = TLI->getName(LibFunc_putchar);
-  Value *PutChar = M->getOrInsertFunction(PutCharName, B.getInt32Ty(), B.getInt32Ty());
+  FunctionCallee PutChar =
+      M->getOrInsertFunction(PutCharName, B.getInt32Ty(), B.getInt32Ty());
   inferLibFuncAttributes(M, PutCharName, *TLI);
   CallInst *CI = B.CreateCall(PutChar,
                               B.CreateIntCast(Char,
                               B.getInt32Ty(),
                               /*isSigned*/true,
                               "chari"),
                               PutCharName);
 
-  if (const Function *F = dyn_cast<Function>(PutChar->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(PutChar.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitPutS(Value *Str, IRBuilder<> &B,
                       const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_puts))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef PutsName = TLI->getName(LibFunc_puts);
-  Value *PutS =
+  FunctionCallee PutS =
       M->getOrInsertFunction(PutsName, B.getInt32Ty(), B.getInt8PtrTy());
   inferLibFuncAttributes(M, PutsName, *TLI);
   CallInst *CI = B.CreateCall(PutS, castToCStr(Str, B), PutsName);
-  if (const Function *F = dyn_cast<Function>(PutS->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(PutS.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFPutC(Value *Char, Value *File, IRBuilder<> &B,
                        const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fputc))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef FPutcName = TLI->getName(LibFunc_fputc);
-  Constant *F = M->getOrInsertFunction(FPutcName, B.getInt32Ty(), B.getInt32Ty(),
-                                       File->getType());
+  FunctionCallee F = M->getOrInsertFunction(FPutcName, B.getInt32Ty(),
+                                            B.getInt32Ty(), File->getType());
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FPutcName, *TLI);
   Char = B.CreateIntCast(Char, B.getInt32Ty(), /*isSigned*/true,
                          "chari");
   CallInst *CI = B.CreateCall(F, {Char, File}, FPutcName);
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFPutCUnlocked(Value *Char, Value *File, IRBuilder<> &B,
                                const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fputc_unlocked))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef FPutcUnlockedName = TLI->getName(LibFunc_fputc_unlocked);
-  Constant *F = M->getOrInsertFunction(FPutcUnlockedName, B.getInt32Ty(),
+  FunctionCallee F = M->getOrInsertFunction(FPutcUnlockedName, B.getInt32Ty(),
                                             B.getInt32Ty(), File->getType());
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FPutcUnlockedName, *TLI);
   Char = B.CreateIntCast(Char, B.getInt32Ty(), /*isSigned*/ true, "chari");
   CallInst *CI = B.CreateCall(F, {Char, File}, FPutcUnlockedName);
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFPutS(Value *Str, Value *File, IRBuilder<> &B,
                        const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fputs))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef FPutsName = TLI->getName(LibFunc_fputs);
-  Constant *F = M->getOrInsertFunction(
-      FPutsName, B.getInt32Ty(), B.getInt8PtrTy(), File->getType());
+  FunctionCallee F = M->getOrInsertFunction(FPutsName, B.getInt32Ty(),
+                                            B.getInt8PtrTy(), File->getType());
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FPutsName, *TLI);
   CallInst *CI = B.CreateCall(F, {castToCStr(Str, B), File}, FPutsName);
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFPutSUnlocked(Value *Str, Value *File, IRBuilder<> &B,
                                const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fputs_unlocked))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef FPutsUnlockedName = TLI->getName(LibFunc_fputs_unlocked);
-  Constant *F = M->getOrInsertFunction(FPutsUnlockedName, B.getInt32Ty(),
+  FunctionCallee F = M->getOrInsertFunction(FPutsUnlockedName, B.getInt32Ty(),
                                             B.getInt8PtrTy(), File->getType());
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FPutsUnlockedName, *TLI);
   CallInst *CI = B.CreateCall(F, {castToCStr(Str, B), File}, FPutsUnlockedName);
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFWrite(Value *Ptr, Value *Size, Value *File, IRBuilder<> &B,
                         const DataLayout &DL, const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fwrite))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   LLVMContext &Context = B.GetInsertBlock()->getContext();
   StringRef FWriteName = TLI->getName(LibFunc_fwrite);
-  Constant *F = M->getOrInsertFunction(
+  FunctionCallee F = M->getOrInsertFunction(
       FWriteName, DL.getIntPtrType(Context), B.getInt8PtrTy(),
       DL.getIntPtrType(Context), DL.getIntPtrType(Context), File->getType());
 
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FWriteName, *TLI);
   CallInst *CI =
       B.CreateCall(F, {castToCStr(Ptr, B), Size,
                        ConstantInt::get(DL.getIntPtrType(Context), 1), File});
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitMalloc(Value *Num, IRBuilder<> &B, const DataLayout &DL,
                         const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_malloc))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef MallocName = TLI->getName(LibFunc_malloc);
   LLVMContext &Context = B.GetInsertBlock()->getContext();
-  Value *Malloc = M->getOrInsertFunction(MallocName, B.getInt8PtrTy(),
+  FunctionCallee Malloc = M->getOrInsertFunction(MallocName, B.getInt8PtrTy(),
                                                  DL.getIntPtrType(Context));
   inferLibFuncAttributes(M, MallocName, *TLI);
   CallInst *CI = B.CreateCall(Malloc, Num, MallocName);
 
-  if (const Function *F = dyn_cast<Function>(Malloc->stripPointerCasts()))
+  if (const Function *F =
+          dyn_cast<Function>(Malloc.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitCalloc(Value *Num, Value *Size, const AttributeList &Attrs,
                         IRBuilder<> &B, const TargetLibraryInfo &TLI) {
   if (!TLI.has(LibFunc_calloc))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef CallocName = TLI.getName(LibFunc_calloc);
   const DataLayout &DL = M->getDataLayout();
   IntegerType *PtrType = DL.getIntPtrType((B.GetInsertBlock()->getContext()));
-  Value *Calloc = M->getOrInsertFunction(CallocName, Attrs, B.getInt8PtrTy(),
-                                         PtrType, PtrType);
+  FunctionCallee Calloc = M->getOrInsertFunction(
+      CallocName, Attrs, B.getInt8PtrTy(), PtrType, PtrType);
   inferLibFuncAttributes(M, CallocName, TLI);
   CallInst *CI = B.CreateCall(Calloc, {Num, Size}, CallocName);
 
-  if (const auto *F = dyn_cast<Function>(Calloc->stripPointerCasts()))
+  if (const auto *F =
+          dyn_cast<Function>(Calloc.getCallee()->stripPointerCasts()))
     CI->setCallingConv(F->getCallingConv());
 
   return CI;
 }
 
 Value *llvm::emitFWriteUnlocked(Value *Ptr, Value *Size, Value *N, Value *File,
                                 IRBuilder<> &B, const DataLayout &DL,
                                 const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fwrite_unlocked))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   LLVMContext &Context = B.GetInsertBlock()->getContext();
   StringRef FWriteUnlockedName = TLI->getName(LibFunc_fwrite_unlocked);
-  Constant *F = M->getOrInsertFunction(
+  FunctionCallee F = M->getOrInsertFunction(
       FWriteUnlockedName, DL.getIntPtrType(Context), B.getInt8PtrTy(),
       DL.getIntPtrType(Context), DL.getIntPtrType(Context), File->getType());
 
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FWriteUnlockedName, *TLI);
   CallInst *CI = B.CreateCall(F, {castToCStr(Ptr, B), Size, N, File});
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFGetCUnlocked(Value *File, IRBuilder<> &B,
                                const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fgetc_unlocked))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef FGetCUnlockedName = TLI->getName(LibFunc_fgetc_unlocked);
-  Constant *F =
-      M->getOrInsertFunction(FGetCUnlockedName, B.getInt32Ty(), File->getType());
+  FunctionCallee F = M->getOrInsertFunction(FGetCUnlockedName, B.getInt32Ty(),
+                                            File->getType());
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FGetCUnlockedName, *TLI);
   CallInst *CI = B.CreateCall(F, File, FGetCUnlockedName);
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFGetSUnlocked(Value *Str, Value *Size, Value *File,
                                IRBuilder<> &B, const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fgets_unlocked))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   StringRef FGetSUnlockedName = TLI->getName(LibFunc_fgets_unlocked);
-  Constant *F =
+  FunctionCallee F =
       M->getOrInsertFunction(FGetSUnlockedName, B.getInt8PtrTy(),
                              B.getInt8PtrTy(), B.getInt32Ty(), File->getType());
   inferLibFuncAttributes(M, FGetSUnlockedName, *TLI);
   CallInst *CI =
       B.CreateCall(F, {castToCStr(Str, B), Size, File}, FGetSUnlockedName);
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }
 
 Value *llvm::emitFReadUnlocked(Value *Ptr, Value *Size, Value *N, Value *File,
                                IRBuilder<> &B, const DataLayout &DL,
                                const TargetLibraryInfo *TLI) {
   if (!TLI->has(LibFunc_fread_unlocked))
     return nullptr;
 
   Module *M = B.GetInsertBlock()->getModule();
   LLVMContext &Context = B.GetInsertBlock()->getContext();
   StringRef FReadUnlockedName = TLI->getName(LibFunc_fread_unlocked);
-  Constant *F = M->getOrInsertFunction(
+  FunctionCallee F = M->getOrInsertFunction(
       FReadUnlockedName, DL.getIntPtrType(Context), B.getInt8PtrTy(),
       DL.getIntPtrType(Context), DL.getIntPtrType(Context), File->getType());
 
   if (File->getType()->isPointerTy())
     inferLibFuncAttributes(M, FReadUnlockedName, *TLI);
   CallInst *CI = B.CreateCall(F, {castToCStr(Ptr, B), Size, N, File});
 
-  if (const Function *Fn = dyn_cast<Function>(F->stripPointerCasts()))
+  if (const Function *Fn =
+          dyn_cast<Function>(F.getCallee()->stripPointerCasts()))
     CI->setCallingConv(Fn->getCallingConv());
   return CI;
 }

llvm/lib/Transforms/Utils/EntryExitInstrumenter.cpp

static void insertCall(Function &CurFn, StringRef Func,
   if (Func == "mcount" ||
       Func == ".mcount" ||
       Func == "\01__gnu_mcount_nc" ||
       Func == "\01_mcount" ||
       Func == "\01mcount" ||
       Func == "__mcount" ||
       Func == "_mcount" ||
       Func == "__cyg_profile_func_enter_bare") {
-    Constant *Fn = M.getOrInsertFunction(Func, Type::getVoidTy(C));
+    FunctionCallee Fn = M.getOrInsertFunction(Func, Type::getVoidTy(C));
     CallInst *Call = CallInst::Create(Fn, "", InsertionPt);
     Call->setDebugLoc(DL);
     return;
   }
 
   if (Func == "__cyg_profile_func_enter" || Func == "__cyg_profile_func_exit") {
     Type *ArgTypes[] = {Type::getInt8PtrTy(C), Type::getInt8PtrTy(C)};
 
-    Constant *Fn = M.getOrInsertFunction(
+    FunctionCallee Fn = M.getOrInsertFunction(
         Func, FunctionType::get(Type::getVoidTy(C), ArgTypes, false));
 
     Instruction *RetAddr = CallInst::Create(
         Intrinsic::getDeclaration(&M, Intrinsic::returnaddress),
         ArrayRef<Value *>(ConstantInt::get(Type::getInt32Ty(C), 0)), "",
         InsertionPt);
     RetAddr->setDebugLoc(DL);
 

llvm/lib/Transforms/Utils/EscapeEnumerator.cpp

 
 #include "llvm/Transforms/Utils/EscapeEnumerator.h"
 #include "llvm/Analysis/EHPersonalities.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Module.h"
 using namespace llvm;
 
-static Constant *getDefaultPersonalityFn(Module *M) {
+static FunctionCallee getDefaultPersonalityFn(Module *M) {
   LLVMContext &C = M->getContext();
   Triple T(M->getTargetTriple());
   EHPersonality Pers = getDefaultEHPersonality(T);
   return M->getOrInsertFunction(getEHPersonalityName(Pers),
                                 FunctionType::get(Type::getInt32Ty(C), true));
 }
 
 IRBuilder<> *EscapeEnumerator::Next() {
IRBuilder<> *EscapeEnumerator::Next() {
   if (Calls.empty())
     return nullptr;
 
   // Create a cleanup block.
   LLVMContext &C = F.getContext();
   BasicBlock *CleanupBB = BasicBlock::Create(C, CleanupBBName, &F);
   Type *ExnTy = StructType::get(Type::getInt8PtrTy(C), Type::getInt32Ty(C));
   if (!F.hasPersonalityFn()) {
-    Constant *PersFn = getDefaultPersonalityFn(F.getParent());
-    F.setPersonalityFn(PersFn);
+    FunctionCallee PersFn = getDefaultPersonalityFn(F.getParent());
+    F.setPersonalityFn(cast<Constant>(PersFn.getCallee()));
   }
 
   if (isScopedEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) {
     report_fatal_error("Scoped EH not supported");
   }
 
   LandingPadInst *LPad =
       LandingPadInst::Create(ExnTy, 1, "cleanup.lpad", CleanupBB);

llvm/lib/Transforms/Utils/ModuleUtils.cpp

 void llvm::appendToUsed(Module &M, ArrayRef<GlobalValue *> Values) {
   appendToUsedList(M, "llvm.used", Values);
 }
 
 void llvm::appendToCompilerUsed(Module &M, ArrayRef<GlobalValue *> Values) {
   appendToUsedList(M, "llvm.compiler.used", Values);
 }
 
-Function *llvm::checkSanitizerInterfaceFunction(Constant *FuncOrBitcast) {
-  if (isa<Function>(FuncOrBitcast))
-    return cast<Function>(FuncOrBitcast);
-  FuncOrBitcast->print(errs());
-  errs() << '\n';
-  std::string Err;
-  raw_string_ostream Stream(Err);
-  Stream << "Sanitizer interface function redefined: " << *FuncOrBitcast;
-  report_fatal_error(Err);
-}
-
-Function *llvm::declareSanitizerInitFunction(Module &M, StringRef InitName,
-                                             ArrayRef<Type *> InitArgTypes) {
+FunctionCallee
+llvm::declareSanitizerInitFunction(Module &M, StringRef InitName,
   assert(!InitName.empty() && "Expected init function name");
-  Function *F = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+  return M.getOrInsertFunction(
       InitName,
       FunctionType::get(Type::getVoidTy(M.getContext()), InitArgTypes, false),
-      AttributeList()));
-  F->setLinkage(Function::ExternalLinkage);
-  return F;
+      AttributeList());
 }
 
-std::pair<Function *, Function *> llvm::createSanitizerCtorAndInitFunctions(
+std::pair<Function *, FunctionCallee> llvm::createSanitizerCtorAndInitFunctions(
     Module &M, StringRef CtorName, StringRef InitName,
     ArrayRef<Type *> InitArgTypes, ArrayRef<Value *> InitArgs,
     StringRef VersionCheckName) {
   assert(!InitName.empty() && "Expected init function name");
   assert(InitArgs.size() == InitArgTypes.size() &&
          "Sanitizer's init function expects different number of arguments");
-  Function *InitFunction =
+  FunctionCallee InitFunction =
       declareSanitizerInitFunction(M, InitName, InitArgTypes);
   Function *Ctor = Function::Create(
       FunctionType::get(Type::getVoidTy(M.getContext()), false),
       GlobalValue::InternalLinkage, CtorName, &M);
   BasicBlock *CtorBB = BasicBlock::Create(M.getContext(), "", Ctor);
   IRBuilder<> IRB(ReturnInst::Create(M.getContext(), CtorBB));
   IRB.CreateCall(InitFunction, InitArgs);
   if (!VersionCheckName.empty()) {
-    Function *VersionCheckFunction =
-        checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-            VersionCheckName, FunctionType::get(IRB.getVoidTy(), {}, false),
-            AttributeList()));
+    FunctionCallee VersionCheckFunction = M.getOrInsertFunction(
+        AttributeList());
     IRB.CreateCall(VersionCheckFunction, {});
   }
   return std::make_pair(Ctor, InitFunction);
 }
 
-std::pair<Function *, Function *>
+std::pair<Function *, FunctionCallee>
 llvm::getOrCreateSanitizerCtorAndInitFunctions(
     Module &M, StringRef CtorName, StringRef InitName,
     ArrayRef<Type *> InitArgTypes, ArrayRef<Value *> InitArgs,
-    function_ref<void(Function *, Function *)> FunctionsCreatedCallback,
+    function_ref<void(Function *, FunctionCallee)> FunctionsCreatedCallback,
     StringRef VersionCheckName) {
   assert(!CtorName.empty() && "Expected ctor function name");
 
   if (Function *Ctor = M.getFunction(CtorName))
     // FIXME: Sink this logic into the module, similar to the handling of
     // globals. This will make moving to a concurrent model much easier.
     if (Ctor->arg_size() == 0 ||
         Ctor->getReturnType() == Type::getVoidTy(M.getContext()))
       return {Ctor, declareSanitizerInitFunction(M, InitName, InitArgTypes)};
 
-  Function *Ctor, *InitFunction;
+  Function *Ctor;
+  FunctionCallee InitFunction;
   std::tie(Ctor, InitFunction) = llvm::createSanitizerCtorAndInitFunctions(
       M, CtorName, InitName, InitArgTypes, InitArgs, VersionCheckName);
   FunctionsCreatedCallback(Ctor, InitFunction);
   return std::make_pair(Ctor, InitFunction);
 }
 
 Function *llvm::getOrCreateInitFunction(Module &M, StringRef Name) {
   assert(!Name.empty() && "Expected init function name");
   if (Function *F = M.getFunction(Name)) {
     if (F->arg_size() != 0 ||
         F->getReturnType() != Type::getVoidTy(M.getContext())) {
       std::string Err;
       raw_string_ostream Stream(Err);
       Stream << "Sanitizer interface function defined with wrong type: " << *F;
       report_fatal_error(Err);
     }
     return F;
   }
-  Function *F = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
-      Name, AttributeList(), Type::getVoidTy(M.getContext())));
-  F->setLinkage(Function::ExternalLinkage);
+  Function *F =
+      cast<Function>(M.getOrInsertFunction(Name, AttributeList(),
+                                           Type::getVoidTy(M.getContext()))
+                         .getCallee());
 
   appendToGlobalCtors(M, F, 0);
 
   return F;
 }
 
 void llvm::filterDeadComdatFunctions(
     Module &M, SmallVectorImpl<Function *> &DeadComdatFunctions) {

llvm/lib/Transforms/Utils/PredicateInfo.cpp

 // Intrinsic::getDeclaration does not handle overloaded unnamed types properly:
 // all unnamed types get mangled to the same string. We use the pointer
 // to the type as name here, as it guarantees unique names for different
 // types and we remove the declarations when destroying PredicateInfo.
 // It is a workaround for PR38117, because solving it in a fully general way is
 // tricky (FIXME).
 static Function *getCopyDeclaration(Module *M, Type *Ty) {
   std::string Name = "llvm.ssa.copy." + utostr((uintptr_t) Ty);
-  return cast<Function>(M->getOrInsertFunction(
-      Name, getType(M->getContext(), Intrinsic::ssa_copy, Ty)));
+  return cast<Function>(
+      M->getOrInsertFunction(Name,
+                             getType(M->getContext(), Intrinsic::ssa_copy, Ty))
+          .getCallee());
 }
 
 // Given the renaming stack, make all the operands currently on the stack real
 // by inserting them into the IR.  Return the last operation's value.
 Value *PredicateInfo::materializeStack(unsigned int &Counter,
                                        ValueDFSStack &RenameStack,
                                        Value *OrigOp) {
   // Find the first thing we have to materialize

llvm/lib/Transforms/Utils/SanitizerStats.cpp

Inits.push_back(ConstantArray::get(
       {Constant::getNullValue(Int8PtrTy),
        ConstantExpr::getIntToPtr(
            ConstantInt::get(IntPtrTy, uint64_t(SK) << (IntPtrTy->getBitWidth() -
                                                        kSanitizerStatKindBits)),
            Int8PtrTy)}));
 
   FunctionType *StatReportTy =
       FunctionType::get(B.getVoidTy(), Int8PtrTy, false);
-  Constant *StatReport = M->getOrInsertFunction(
-      "__sanitizer_stat_report", StatReportTy);
+  FunctionCallee StatReport =
+      M->getOrInsertFunction("__sanitizer_stat_report", StatReportTy);
 
   auto InitAddr = ConstantExpr::getGetElementPtr(
       EmptyModuleStatsTy, ModuleStatsGV,
       ArrayRef<Constant *>{
           ConstantInt::get(IntPtrTy, 0), ConstantInt::get(B.getInt32Ty(), 2),
           ConstantInt::get(IntPtrTy, Inits.size() - 1),
       });
   B.CreateCall(StatReport, ConstantExpr::getBitCast(InitAddr, Int8PtrTy));
void SanitizerStatReport::finish() {
 
   // Create a global constructor to register NewModuleStatsGV.
   auto F = Function::Create(FunctionType::get(VoidTy, false),
                             GlobalValue::InternalLinkage, "", M);
   auto BB = BasicBlock::Create(M->getContext(), "", F);
   IRBuilder<> B(BB);
 
   FunctionType *StatInitTy = FunctionType::get(VoidTy, Int8PtrTy, false);
-  Constant *StatInit = M->getOrInsertFunction(
-      "__sanitizer_stat_init", StatInitTy);
+  FunctionCallee StatInit =
+      M->getOrInsertFunction("__sanitizer_stat_init", StatInitTy);
 
   B.CreateCall(StatInit, ConstantExpr::getBitCast(NewModuleStatsGV, Int8PtrTy));
   B.CreateRetVoid();
 
   appendToGlobalCtors(*M, F, 0);
 }

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

if (TLI->has(LdExp)) {
     }
 
     if (LdExpArg) {
       Constant *One = ConstantFP::get(CI->getContext(), APFloat(1.0f));
       if (!Op->getType()->isFloatTy())
         One = ConstantExpr::getFPExtend(One, Op->getType());
 
       Module *M = CI->getModule();
-      Value *NewCallee =
-          M->getOrInsertFunction(TLI->getName(LdExp), Op->getType(),
-                                 Op->getType(), B.getInt32Ty());
+      FunctionCallee NewCallee = M->getOrInsertFunction(
+          TLI->getName(LdExp), Op->getType(), Op->getType(), B.getInt32Ty());
       CallInst *CI = B.CreateCall(NewCallee, {One, LdExpArg});
       if (const Function *F = dyn_cast<Function>(Callee->stripPointerCasts()))
         CI->setCallingConv(F->getCallingConv());
 
       return CI;
     }
   }
   return Ret;
ResTy = T.getArch() == Triple::x86_64
                 ? static_cast<Type *>(VectorType::get(ArgTy, 2))
                 : static_cast<Type *>(StructType::get(ArgTy, ArgTy));
   } else {
     Name = "__sincospi_stret";
     ResTy = StructType::get(ArgTy, ArgTy);
   }
 
   Module *M = OrigCallee->getParent();
-  Value *Callee = M->getOrInsertFunction(Name, OrigCallee->getAttributes(),
-                                         ResTy, ArgTy);
+  FunctionCallee Callee =
+      M->getOrInsertFunction(Name, OrigCallee->getAttributes(), ResTy, ArgTy);
 
   if (Instruction *ArgInst = dyn_cast<Instruction>(Arg)) {
     // If the argument is an instruction, it must dominate all uses so put our
     // sincos call there.
     B.SetInsertPoint(ArgInst->getParent(), ++ArgInst->getIterator());
   } else {
     // Otherwise (e.g. for a constant) the beginning of the function is as
     // good a place as any.
Value *LibCallSimplifier::optimizePrintF(CallInst *CI, IRBuilder<> &B) {
   if (Value *V = optimizePrintFString(CI, B)) {
     return V;
   }
 
   // printf(format, ...) -> iprintf(format, ...) if no floating point
   // arguments.
   if (TLI->has(LibFunc_iprintf) && !callHasFloatingPointArgument(CI)) {
     Module *M = B.GetInsertBlock()->getParent()->getParent();
-    Constant *IPrintFFn =
+    FunctionCallee IPrintFFn =
         M->getOrInsertFunction("iprintf", FT, Callee->getAttributes());
     CallInst *New = cast<CallInst>(CI->clone());
     New->setCalledFunction(IPrintFFn);
     B.Insert(New);
     return New;
   }
   return nullptr;
 }
Value *LibCallSimplifier::optimizeSPrintF(CallInst *CI, IRBuilder<> &B) {
   if (Value *V = optimizeSPrintFString(CI, B)) {
     return V;
   }
 
   // sprintf(str, format, ...) -> siprintf(str, format, ...) if no floating
   // point arguments.
   if (TLI->has(LibFunc_siprintf) && !callHasFloatingPointArgument(CI)) {
     Module *M = B.GetInsertBlock()->getParent()->getParent();
-    Constant *SIPrintFFn =
+    FunctionCallee SIPrintFFn =
         M->getOrInsertFunction("siprintf", FT, Callee->getAttributes());
     CallInst *New = cast<CallInst>(CI->clone());
     New->setCalledFunction(SIPrintFFn);
     B.Insert(New);
     return New;
   }
   return nullptr;
 }
Value *LibCallSimplifier::optimizeFPrintF(CallInst *CI, IRBuilder<> &B) {
   if (Value *V = optimizeFPrintFString(CI, B)) {
     return V;
   }
 
   // fprintf(stream, format, ...) -> fiprintf(stream, format, ...) if no
   // floating point arguments.
   if (TLI->has(LibFunc_fiprintf) && !callHasFloatingPointArgument(CI)) {
     Module *M = B.GetInsertBlock()->getParent()->getParent();
-    Constant *FIPrintFFn =
+    FunctionCallee FIPrintFFn =
         M->getOrInsertFunction("fiprintf", FT, Callee->getAttributes());
     CallInst *New = cast<CallInst>(CI->clone());
     New->setCalledFunction(FIPrintFFn);
     B.Insert(New);
     return New;
   }
   return nullptr;
 }

llvm/tools/bugpoint/Miscompilation.cpp

CleanupAndPrepareModules(BugDriver &BD, std::unique_ptr<Module> Test,
 
   // The second nasty issue we must deal with in the JIT is that the Safe
   // module cannot directly reference any functions defined in the test
   // module.  Instead, we use a JIT API call to dynamically resolve the
   // symbol.
 
   // Add the resolver to the Safe module.
   // Prototype: void *getPointerToNamedFunction(const char* Name)
-  Constant *resolverFunc = Safe->getOrInsertFunction(
+  FunctionCallee resolverFunc = Safe->getOrInsertFunction(
       "getPointerToNamedFunction", Type::getInt8PtrTy(Safe->getContext()),
       Type::getInt8PtrTy(Safe->getContext()));
 
   // Use the function we just added to get addresses of functions we need.
   for (Module::iterator F = Safe->begin(), E = Safe->end(); F != E; ++F) {
-    if (F->isDeclaration() && !F->use_empty() && &*F != resolverFunc &&
+    if (F->isDeclaration() && !F->use_empty() &&
+        &*F != resolverFunc.getCallee() &&
         !F->isIntrinsic() /* ignore intrinsics */) {
       Function *TestFn = Test->getFunction(F->getName());
 
       // Don't forward functions which are external in the test module too.
       if (TestFn && !TestFn->isDeclaration()) {
         // 1. Add a string constant with its name to the global file
         Constant *InitArray =
             ConstantDataArray::getString(F->getContext(), F->getName());

llvm/tools/lli/lli.cpp

if (ChildExecPath.empty()) {
       return -1;
     }
 #endif
   }
 
   if (!RemoteMCJIT) {
     // If the program doesn't explicitly call exit, we will need the Exit
     // function later on to make an explicit call, so get the function now.
-    Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
-                                                      Type::getInt32Ty(Context));
+    FunctionCallee Exit = Mod->getOrInsertFunction(
+        "exit", Type::getVoidTy(Context), Type::getInt32Ty(Context));
 
     // Run static constructors.
     if (!ForceInterpreter) {
       // Give MCJIT a chance to apply relocations and set page permissions.
       EE->finalizeObject();
     }
     EE->runStaticConstructorsDestructors(false);
 
     // Trigger compilation separately so code regions that need to be
     // invalidated will be known.
     (void)EE->getPointerToFunction(EntryFn);
     // Clear instruction cache before code will be executed.
     if (RTDyldMM)
       static_cast<SectionMemoryManager*>(RTDyldMM)->invalidateInstructionCache();
 
     // Run main.
     Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
 
     // Run static destructors.
     EE->runStaticConstructorsDestructors(true);
 
     // If the program didn't call exit explicitly, we should call it now.
     // This ensures that any atexit handlers get called correctly.
-    if (Function *ExitF = dyn_cast<Function>(Exit)) {
+    if (Function *ExitF =
+            dyn_cast<Function>(Exit.getCallee()->stripPointerCasts())) {
+      if (ExitF->getFunctionType() == Exit.getFunctionType()) {
         std::vector<GenericValue> Args;
         GenericValue ResultGV;
         ResultGV.IntVal = APInt(32, Result);
         Args.push_back(ResultGV);
         EE->runFunction(ExitF, Args);
-      WithColor::error(errs(), argv[0]) << "exit(" << Result << ") returned!\n";
-      abort();
-    } else {
         WithColor::error(errs(), argv[0])
-          << "exit defined with wrong prototype!\n";
+            << "exit(" << Result << ") returned!\n";
         abort();
       }
+    }
+    WithColor::error(errs(), argv[0]) << "exit defined with wrong prototype!\n";
+    abort();
   } else {
     // else == "if (RemoteMCJIT)"
 
     // Remote target MCJIT doesn't (yet) support static constructors. No reason
     // it couldn't. This is a limitation of the LLI implementation, not the
     // MCJIT itself. FIXME.
 
     // Lanch the remote process and get a channel to it.

llvm/unittests/Analysis/AliasAnalysisTest.cpp

AAResults &getAAResults(Function &F) {
     return *AAR;
   }
 };
 
 TEST_F(AliasAnalysisTest, getModRefInfo) {
   // Setup function.
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(C), std::vector<Type *>(), false);
-  auto *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  auto *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   auto *BB = BasicBlock::Create(C, "entry", F);
   auto IntType = Type::getInt32Ty(C);
   auto PtrType = Type::getInt32PtrTy(C);
   auto *Value = ConstantInt::get(IntType, 42);
   auto *Addr = ConstantPointerNull::get(PtrType);
 
   auto *Store1 = new StoreInst(Value, Addr, BB);
   auto *Load1 = new LoadInst(Addr, "load", BB);

llvm/unittests/Analysis/DivergenceAnalysisTest.cpp

protected:
   }
 };
 
 // Simple initial state test
 TEST_F(DivergenceAnalysisTest, DAInitialState) {
   IntegerType *IntTy = IntegerType::getInt32Ty(Context);
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), {IntTy}, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
   ReturnInst::Create(Context, nullptr, BB);
 
   DivergenceAnalysis DA = buildDA(*F, false);
 
   // Whole function region
   EXPECT_EQ(DA.getRegionLoop(), nullptr);
 

llvm/unittests/Analysis/OrderedInstructionsTest.cpp

 /// Check intra-basicblock and inter-basicblock dominance using
 /// OrderedInstruction.
 TEST(OrderedInstructionsTest, DominanceTest) {
   LLVMContext Ctx;
   Module M("test", Ctx);
   IRBuilder<> B(Ctx);
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Ctx), {B.getInt8PtrTy()}, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
 
   // Create the function as follow and check for dominance relation.
   //
   // test():
   //  bbx:
   //    loadx;
   //    loady;
   //  bby:

llvm/unittests/Analysis/PhiValuesTest.cpp

TEST(PhiValuesTest, SimplePhi) {
   Module M("PhiValuesTest", C);
 
   Type *VoidTy = Type::getVoidTy(C);
   Type *I1Ty = Type::getInt1Ty(C);
   Type *I32Ty = Type::getInt32Ty(C);
   Type *I32PtrTy = Type::getInt32PtrTy(C);
 
   // Create a function with phis that do not have other phis as incoming values
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FunctionType::get(VoidTy, false)));
+  Function *F = Function::Create(FunctionType::get(VoidTy, false),
+                                 Function::ExternalLinkage, "f", M);
 
   BasicBlock *Entry = BasicBlock::Create(C, "entry", F);
   BasicBlock *If = BasicBlock::Create(C, "if", F);
   BasicBlock *Else = BasicBlock::Create(C, "else", F);
   BasicBlock *Then = BasicBlock::Create(C, "then", F);
   BranchInst::Create(If, Else, UndefValue::get(I1Ty), Entry);
   BranchInst::Create(Then, If);
   BranchInst::Create(Then, Else);
TEST(PhiValuesTest, DependentPhi) {
   Module M("PhiValuesTest", C);
 
   Type *VoidTy = Type::getVoidTy(C);
   Type *I1Ty = Type::getInt1Ty(C);
   Type *I32Ty = Type::getInt32Ty(C);
   Type *I32PtrTy = Type::getInt32PtrTy(C);
 
   // Create a function with a phi that has another phi as an incoming value
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FunctionType::get(VoidTy, false)));
+  Function *F = Function::Create(FunctionType::get(VoidTy, false),
+                                 Function::ExternalLinkage, "f", M);
 
   BasicBlock *Entry = BasicBlock::Create(C, "entry", F);
   BasicBlock *If1 = BasicBlock::Create(C, "if1", F);
   BasicBlock *Else1 = BasicBlock::Create(C, "else1", F);
   BasicBlock *Then = BasicBlock::Create(C, "then", F);
   BasicBlock *If2 = BasicBlock::Create(C, "if2", F);
   BasicBlock *Else2 = BasicBlock::Create(C, "else2", F);
   BasicBlock *End = BasicBlock::Create(C, "then", F);

llvm/unittests/Analysis/ScalarEvolutionTest.cpp

void runWithSE(
     ScalarEvolution SE = buildSE(*F);
     Test(*F, *LI, SE);
   }
 };
 
 TEST_F(ScalarEvolutionsTest, SCEVUnknownRAUW) {
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
                                               std::vector<Type *>(), false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
   ReturnInst::Create(Context, nullptr, BB);
 
   Type *Ty = Type::getInt1Ty(Context);
   Constant *Init = Constant::getNullValue(Ty);
   Value *V0 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V0");
   Value *V1 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V1");
   Value *V2 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V2");
TEST_F(ScalarEvolutionsTest, SCEVUnknownRAUW) {
   EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
   EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V0);
   EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V0);
 }
 
 TEST_F(ScalarEvolutionsTest, SimplifiedPHI) {
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
                                               std::vector<Type *>(), false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
   BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
   BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
   BranchInst::Create(LoopBB, EntryBB);
   BranchInst::Create(LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)),
                      LoopBB);
   ReturnInst::Create(Context, nullptr, ExitBB);
   auto *Ty = Type::getInt32Ty(Context);
TEST_F(ScalarEvolutionsTest, ExpandPtrTypeSCEV) {
   // expansion when the value in ValueOffsetPair is a ptr and the offset
   // is not divisible by the elem type size of value.
   auto *I8Ty = Type::getInt8Ty(Context);
   auto *I8PtrTy = Type::getInt8PtrTy(Context);
   auto *I32Ty = Type::getInt32Ty(Context);
   auto *I32PtrTy = Type::getInt32PtrTy(Context);
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
   BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
   BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
   BranchInst::Create(LoopBB, EntryBB);
   ReturnInst::Create(Context, nullptr, ExitBB);
 
   // loop:                            ; preds = %loop, %entry
   //   %alloca = alloca i32
runWithSE(
                                    SE.getSCEV(getInstructionByName(F, "y")),
                                    SE.getSCEV(getInstructionByName(F, "z")));
         });
 }
 
 TEST_F(ScalarEvolutionsTest, CompareSCEVComplexity) {
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
   BasicBlock *LoopBB = BasicBlock::Create(Context, "bb1", F);
   BranchInst::Create(LoopBB, EntryBB);
 
   auto *Ty = Type::getInt32Ty(Context);
   SmallVector<Instruction*, 8> Muls(8), Acc(8), NextAcc(8);
 
   Acc[0] = PHINode::Create(Ty, 2, "", LoopBB);

 }
 
 TEST_F(ScalarEvolutionsTest, CompareValueComplexity) {
   IntegerType *IntPtrTy = M.getDataLayout().getIntPtrType(Context);
   PointerType *IntPtrPtrTy = IntPtrTy->getPointerTo();
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), {IntPtrTy, IntPtrTy}, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
 
   Value *X = &*F->arg_begin();
   Value *Y = &*std::next(F->arg_begin());
 
   const int ValueDepth = 10;
   for (int i = 0; i < ValueDepth; i++) {
     X = new LoadInst(new IntToPtrInst(X, IntPtrPtrTy, "", EntryBB), "",

 }
 
 TEST_F(ScalarEvolutionsTest, SCEVAddExpr) {
   Type *Ty32 = Type::getInt32Ty(Context);
   Type *ArgTys[] = {Type::getInt64Ty(Context), Ty32};
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), ArgTys, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
 
   Argument *A1 = &*F->arg_begin();
   Argument *A2 = &*(std::next(F->arg_begin()));
   BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
 
   Instruction *Trunc = CastInst::CreateTruncOrBitCast(A1, Ty32, "", EntryBB);
   Instruction *Mul1 = BinaryOperator::CreateMul(Trunc, A2, "", EntryBB);
   Instruction *Add1 = BinaryOperator::CreateAdd(Mul1, Trunc, "", EntryBB);
TEST_F(ScalarEvolutionsTest, SCEVZeroExtendExpr) {
   // for.end:
   //   %gep = getelementptr i8, i8* null, i64 %dec
   //   %gep6 = getelementptr i8, i8* %gep, i64 %dec5
   //   ......
   //   %gep95 = getelementptr i8, i8* %gep91, i64 %dec94
   //   ret void
   // }
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), {}, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
 
   BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
   BasicBlock *CondBB = BasicBlock::Create(Context, "for.cond", F);
   BasicBlock *EndBB = BasicBlock::Create(Context, "for.end", F);
   BranchInst::Create(CondBB, EntryBB);
   BasicBlock *PrevBB = EntryBB;
 
   Type *I64Ty = Type::getInt64Ty(Context);
TEST_F(ScalarEvolutionsTest, SCEVZeroExtendExprNonIntegral) {
   NIM.setDataLayout(DataLayout);
 
   Type *T_int1 = Type::getInt1Ty(Context);
   Type *T_int64 = Type::getInt64Ty(Context);
   Type *T_pint64 = T_int64->getPointerTo(10);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
-  Function *F = cast<Function>(NIM.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", NIM);
 
   Argument *Arg = &*F->arg_begin();
 
   BasicBlock *Top = BasicBlock::Create(Context, "top", F);
   BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
   BasicBlock *L = BasicBlock::Create(Context, "L", F);
   BasicBlock *Post = BasicBlock::Create(Context, "post", F);
 
TEST_F(ScalarEvolutionsTest, SCEVExitLimitForgetLoop) {
   DataLayout += "ni:10";
   NIM.setDataLayout(DataLayout);
 
   Type *T_int64 = Type::getInt64Ty(Context);
   Type *T_pint64 = T_int64->getPointerTo(10);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
-  Function *F = cast<Function>(NIM.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", NIM);
 
   BasicBlock *Top = BasicBlock::Create(Context, "top", F);
   BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
   BasicBlock *L = BasicBlock::Create(Context, "L", F);
   BasicBlock *Post = BasicBlock::Create(Context, "post", F);
 
   IRBuilder<> Builder(Top);
   Builder.CreateBr(LPh);
TEST_F(ScalarEvolutionsTest, SCEVExitLimitForgetValue) {
   DataLayout += "ni:10";
   NIM.setDataLayout(DataLayout);
 
   Type *T_int64 = Type::getInt64Ty(Context);
   Type *T_pint64 = T_int64->getPointerTo(10);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
-  Function *F = cast<Function>(NIM.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", NIM);
 
   Argument *Arg = &*F->arg_begin();
 
   BasicBlock *Top = BasicBlock::Create(Context, "top", F);
   BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
   BasicBlock *L = BasicBlock::Create(Context, "L", F);
   BasicBlock *Post = BasicBlock::Create(Context, "post", F);
 
TEST_F(ScalarEvolutionsTest, SCEVAddRecFromPHIwithLargeConstants) {
   // Make sure that SCEV does not blow up when constructing an AddRec
   // with predicates for a phi with the update pattern:
   //  (SExt/ZExt ix (Trunc iy (%SymbolicPHI) to ix) to iy) + InvariantAccum
   // when either the initial value of the Phi or the InvariantAccum are
   // constants that are too large to fit in an ix but are zero when truncated to
   // ix.
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
-  Function *F = cast<Function>(M.getOrInsertFunction("addrecphitest", FTy));
+  Function *F =
+      Function::Create(FTy, Function::ExternalLinkage, "addrecphitest", M);
 
   /*
     Create IR:
     entry:
      br label %loop
     loop:
      %0 = phi i64 [-9223372036854775808, %entry], [%3, %loop]
      %1 = shl i64 %0, 32
TEST_F(ScalarEvolutionsTest, SCEVAddRecFromPHIwithLargeConstantAccum) {
   //  (SExt/ZExt ix (Trunc iy (%SymbolicPHI) to ix) to iy) + InvariantAccum
   // when the InvariantAccum is a constant that is too large to fit in an
   // ix but are zero when truncated to ix, and the initial value of the
   // phi is not a constant.
   Type *Int32Ty = Type::getInt32Ty(Context);
   SmallVector<Type *, 1> Types;
   Types.push_back(Int32Ty);
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Types, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("addrecphitest", FTy));
+  Function *F =
+      Function::Create(FTy, Function::ExternalLinkage, "addrecphitest", M);
 
   /*
     Create IR:
     define @addrecphitest(i32)
     entry:
      br label %loop
     loop:
      %1 = phi i32 [%0, %entry], [%4, %loop]

 TEST_F(ScalarEvolutionsTest, SCEVFoldSumOfTruncs) {
   // Verify that the following SCEV gets folded to a zero:
   //  (-1 * (trunc i64 (-1 * %0) to i32)) + (-1 * (trunc i64 %0 to i32)
   Type *ArgTy = Type::getInt64Ty(Context);
   Type *Int32Ty = Type::getInt32Ty(Context);
   SmallVector<Type *, 1> Types;
   Types.push_back(ArgTy);
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Types, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
   ReturnInst::Create(Context, nullptr, BB);
 
   ScalarEvolution SE = buildSE(*F);
 
   auto *Arg = &*(F->arg_begin());
   const auto *ArgSCEV = SE.getSCEV(Arg);
 
TEST_F(ScalarEvolutionsTest, SCEVExpanderIsSafeToExpandAt) {
   DataLayout += "ni:10";
   NIM.setDataLayout(DataLayout);
 
   Type *T_int64 = Type::getInt64Ty(Context);
   Type *T_pint64 = T_int64->getPointerTo(10);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
-  Function *F = cast<Function>(NIM.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", NIM);
 
   BasicBlock *Top = BasicBlock::Create(Context, "top", F);
   BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
   BasicBlock *L = BasicBlock::Create(Context, "L", F);
   BasicBlock *Post = BasicBlock::Create(Context, "post", F);
 
   IRBuilder<> Builder(Top);
   Builder.CreateBr(LPh);
TEST_F(ScalarEvolutionsTest, SCEVExpanderNUW) {
 
   // Create a module.
   Module M("SCEVExpanderNUW", Context);
 
   Type *T_int64 = Type::getInt64Ty(Context);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), { T_int64 }, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("func", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "func", M);
   Argument *Arg = &*F->arg_begin();
   ConstantInt *C = ConstantInt::get(Context, APInt(64, -1));
 
   BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
   BasicBlock *Body = BasicBlock::Create(Context, "body", F);
   BasicBlock *Exit = BasicBlock::Create(Context, "exit", F);
 
   IRBuilder<> Builder(Entry);
TEST_F(ScalarEvolutionsTest, SCEVExpanderNSW) {
 
   // Create a module.
   Module M("SCEVExpanderNSW", Context);
 
   Type *T_int64 = Type::getInt64Ty(Context);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), { T_int64 }, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("func", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "func", M);
   Argument *Arg = &*F->arg_begin();
   ConstantInt *C = ConstantInt::get(Context, APInt(64, -1));
 
   BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
   BasicBlock *Body = BasicBlock::Create(Context, "body", F);
   BasicBlock *Exit = BasicBlock::Create(Context, "exit", F);
 
   IRBuilder<> Builder(Entry);
TEST_F(ScalarEvolutionsTest, SCEVCacheNUW) {
 
   // Create a module.
   Module M("SCEVCacheNUW", Context);
 
   Type *T_int64 = Type::getInt64Ty(Context);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), { T_int64 }, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("func", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "func", M);
   Argument *Arg = &*F->arg_begin();
   ConstantInt *C = ConstantInt::get(Context, APInt(64, -1));
 
   BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
   BasicBlock *Exit = BasicBlock::Create(Context, "exit", F);
 
   IRBuilder<> Builder(Entry);
   auto *S1 = cast<Instruction>(Builder.CreateAdd(Arg, C, "add"));
TEST_F(ScalarEvolutionsTest, SCEVCacheNSW) {
 
   // Create a module.
   Module M("SCEVCacheNUW", Context);
 
   Type *T_int64 = Type::getInt64Ty(Context);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), { T_int64 }, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("func", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "func", M);
   Argument *Arg = &*F->arg_begin();
   ConstantInt *C = ConstantInt::get(Context, APInt(64, -1));
 
   BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
   BasicBlock *Exit = BasicBlock::Create(Context, "exit", F);
 
   IRBuilder<> Builder(Entry);
   auto *S1 = cast<Instruction>(Builder.CreateAdd(Arg, C, "add"));
TEST_F(ScalarEvolutionsTest, SCEVComputeExpressionSize) {
 
   // Create a module.
   Module M("SCEVComputeExpressionSize", Context);
 
   Type *T_int64 = Type::getInt64Ty(Context);
 
   FunctionType *FTy =
       FunctionType::get(Type::getVoidTy(Context), { T_int64, T_int64 }, false);
-  Function *F = cast<Function>(M.getOrInsertFunction("func", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "func", M);
   Argument *A = &*F->arg_begin();
   Argument *B = &*std::next(F->arg_begin());
   ConstantInt *C = ConstantInt::get(Context, APInt(64, 1));
 
   BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
   BasicBlock *Exit = BasicBlock::Create(Context, "exit", F);
 
   IRBuilder<> Builder(Entry);

llvm/unittests/Analysis/TBAATest.cpp

protected:
   LLVMContext C;
   Module M;
   MDBuilder MD;
 };
 
 static StoreInst *getFunctionWithSingleStore(Module *M, StringRef Name) {
   auto &C = M->getContext();
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), {});
-  auto *F = cast<Function>(M->getOrInsertFunction(Name, FTy));
+  auto *F = Function::Create(FTy, Function::ExternalLinkage, Name, M);
   auto *BB = BasicBlock::Create(C, "entry", F);
   auto *IntType = Type::getInt32Ty(C);
   auto *PtrType = Type::getInt32PtrTy(C);
   auto *SI = new StoreInst(ConstantInt::get(IntType, 42),
                            ConstantPointerNull::get(PtrType), BB);
   ReturnInst::Create(C, nullptr, BB);
 
   return SI;

llvm/unittests/Analysis/TargetLibraryInfoTest.cpp

TEST_F(TargetLibraryInfoTest, InvalidProto) {
   parseAssembly("%foo = type { %foo }\n");
 
   auto *StructTy = M->getTypeByName("foo");
   auto *InvalidFTy = FunctionType::get(StructTy, /*isVarArg=*/false);
 
   for (unsigned FI = 0; FI != LibFunc::NumLibFuncs; ++FI) {
     LibFunc LF = (LibFunc)FI;
     auto *F = cast<Function>(
-        M->getOrInsertFunction(TLI.getName(LF), InvalidFTy));
+        M->getOrInsertFunction(TLI.getName(LF), InvalidFTy).getCallee());
     EXPECT_FALSE(isLibFunc(F, LF));
   }
 }
 
 // Check that we do accept know-correct prototypes.
 TEST_F(TargetLibraryInfoTest, ValidProto) {
   parseAssembly(
       // These functions use a 64-bit size_t; use the appropriate datalayout.

llvm/unittests/IR/CFGBuilder.cpp

 #define DEBUG_TYPE "cfg-builder"
 
 using namespace llvm;
 
 CFGHolder::CFGHolder(StringRef ModuleName, StringRef FunctionName)
     : Context(llvm::make_unique<LLVMContext>()),
       M(llvm::make_unique<Module>(ModuleName, *Context)) {
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Context), {}, false);
-  F = cast<Function>(M->getOrInsertFunction(FunctionName, FTy));
+  F = Function::Create(FTy, Function::ExternalLinkage, FunctionName, M.get());
 }
 CFGHolder::~CFGHolder() = default;
 
 CFGBuilder::CFGBuilder(Function *F, const std::vector<Arc> &InitialArcs,
                        std::vector<Update> Updates)
     : F(F), Updates(std::move(Updates)) {
   assert(F);
   buildCFG(InitialArcs);

llvm/unittests/IR/MetadataTest.cpp

ConstantAsMetadata *getConstantAsMetadata() {
     return ConstantAsMetadata::get(getConstant());
   }
   DIType *getCompositeType() {
     return DICompositeType::getDistinct(
         Context, dwarf::DW_TAG_structure_type, "", nullptr, 0, nullptr, nullptr,
         32, 32, 0, DINode::FlagZero, nullptr, 0, nullptr, nullptr, "");
   }
   Function *getFunction(StringRef Name) {
-    return cast<Function>(M.getOrInsertFunction(
-        Name, FunctionType::get(Type::getVoidTy(Context), None, false)));
+    return Function::Create(
+        FunctionType::get(Type::getVoidTy(Context), None, false),
+        Function::ExternalLinkage, Name, M);
   }
 };
 typedef MetadataTest MDStringTest;
 
 // Test that construction of MDString with different value produces different
 // MDString objects, even with the same string pointer and nulls in the string.
 TEST_F(MDStringTest, CreateDifferent) {
   char x[3] = { 'f', 0, 'A' };

llvm/unittests/IR/VerifierTest.cpp

 
 namespace llvm {
 namespace {
 
 TEST(VerifierTest, Branch_i1) {
   LLVMContext C;
   Module M("M", C);
   FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), /*isVarArg=*/false);
-  Function *F = cast<Function>(M.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
   BasicBlock *Entry = BasicBlock::Create(C, "entry", F);
   BasicBlock *Exit = BasicBlock::Create(C, "exit", F);
   ReturnInst::Create(C, Exit);
 
   // To avoid triggering an assertion in BranchInst::Create, we first create
   // a branch with an 'i1' condition ...
 
   Constant *False = ConstantInt::getFalse(C);
   BranchInst *BI = BranchInst::Create(Exit, Exit, False, Entry);
 
   // ... then use setOperand to redirect it to a value of different type.
 
   Constant *Zero32 = ConstantInt::get(IntegerType::get(C, 32), 0);
   BI->setOperand(0, Zero32);
 
   EXPECT_TRUE(verifyFunction(*F));
 }
 
 TEST(VerifierTest, InvalidRetAttribute) {
   LLVMContext C;
   Module M("M", C);
   FunctionType *FTy = FunctionType::get(Type::getInt32Ty(C), /*isVarArg=*/false);
-  Function *F = cast<Function>(M.getOrInsertFunction("foo", FTy));
+  Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
   AttributeList AS = F->getAttributes();
   F->setAttributes(
       AS.addAttribute(C, AttributeList::ReturnIndex, Attribute::UWTable));
 
   std::string Error;
   raw_string_ostream ErrorOS(Error);
   EXPECT_TRUE(verifyModule(M, &ErrorOS));
   EXPECT_TRUE(StringRef(ErrorOS.str()).startswith(
       "Attribute 'uwtable' only applies to functions!"));
 }
 
 TEST(VerifierTest, CrossModuleRef) {
   LLVMContext C;
   Module M1("M1", C);
   Module M2("M2", C);
   Module M3("M3", C);
   FunctionType *FTy = FunctionType::get(Type::getInt32Ty(C), /*isVarArg=*/false);
-  Function *F1 = cast<Function>(M1.getOrInsertFunction("foo1", FTy));
-  Function *F2 = cast<Function>(M2.getOrInsertFunction("foo2", FTy));
-  Function *F3 = cast<Function>(M3.getOrInsertFunction("foo3", FTy));
+  Function *F1 = Function::Create(FTy, Function::ExternalLinkage, "foo1", M1);
+  Function *F2 = Function::Create(FTy, Function::ExternalLinkage, "foo2", M2);
+  Function *F3 = Function::Create(FTy, Function::ExternalLinkage, "foo3", M3);
 
   BasicBlock *Entry1 = BasicBlock::Create(C, "entry", F1);
   BasicBlock *Entry3 = BasicBlock::Create(C, "entry", F3);
 
   // BAD: Referencing function in another module
   CallInst::Create(F2,"call",Entry1);
 
   // BAD: Referencing personality routine in another module
TEST(VerifierTest, DetectInvalidDebugInfo) {
     Module M("M", C);
     DIBuilder DIB(M);
     auto *CU = DIB.createCompileUnit(dwarf::DW_LANG_C89,
                                      DIB.createFile("broken.c", "/"),
                                      "unittest", false, "", 0);
     new GlobalVariable(M, Type::getInt8Ty(C), false,
                        GlobalValue::ExternalLinkage, nullptr, "g");
 
-    auto *F = cast<Function>(M.getOrInsertFunction(
-        "f", FunctionType::get(Type::getVoidTy(C), false)));
+    auto *F = Function::Create(FunctionType::get(Type::getVoidTy(C), false),
+                               Function::ExternalLinkage, "f", M);
     IRBuilder<> Builder(BasicBlock::Create(C, "", F));
     Builder.CreateUnreachable();
     F->setSubprogram(DIB.createFunction(
         CU, "f", "f", DIB.createFile("broken.c", "/"), 1, nullptr, 1,
         DINode::FlagZero,
         DISubprogram::SPFlagLocalToUnit | DISubprogram::SPFlagDefinition));
     DIB.finalize();
     EXPECT_FALSE(verifyModule(M));