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      1 //===---- llvm/IRBuilder.h - Builder for LLVM Instructions ------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the IRBuilder class, which is used as a convenient way
     11 // to create LLVM instructions with a consistent and simplified interface.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_IR_IRBUILDER_H
     16 #define LLVM_IR_IRBUILDER_H
     17 
     18 #include "llvm/ADT/ArrayRef.h"
     19 #include "llvm/ADT/StringRef.h"
     20 #include "llvm/ADT/Twine.h"
     21 #include "llvm/IR/BasicBlock.h"
     22 #include "llvm/IR/ConstantFolder.h"
     23 #include "llvm/IR/DataLayout.h"
     24 #include "llvm/IR/GlobalVariable.h"
     25 #include "llvm/IR/Instructions.h"
     26 #include "llvm/IR/LLVMContext.h"
     27 #include "llvm/IR/Operator.h"
     28 #include "llvm/IR/ValueHandle.h"
     29 #include "llvm/Support/CBindingWrapping.h"
     30 
     31 namespace llvm {
     32 class MDNode;
     33 
     34 /// \brief This provides the default implementation of the IRBuilder
     35 /// 'InsertHelper' method that is called whenever an instruction is created by
     36 /// IRBuilder and needs to be inserted.
     37 ///
     38 /// By default, this inserts the instruction at the insertion point.
     39 template <bool preserveNames = true>
     40 class IRBuilderDefaultInserter {
     41 protected:
     42   void InsertHelper(Instruction *I, const Twine &Name,
     43                     BasicBlock *BB, BasicBlock::iterator InsertPt) const {
     44     if (BB) BB->getInstList().insert(InsertPt, I);
     45     if (preserveNames)
     46       I->setName(Name);
     47   }
     48 };
     49 
     50 /// \brief Common base class shared among various IRBuilders.
     51 class IRBuilderBase {
     52   DebugLoc CurDbgLocation;
     53 protected:
     54   BasicBlock *BB;
     55   BasicBlock::iterator InsertPt;
     56   LLVMContext &Context;
     57 
     58   MDNode *DefaultFPMathTag;
     59   FastMathFlags FMF;
     60 public:
     61 
     62   IRBuilderBase(LLVMContext &context, MDNode *FPMathTag = nullptr)
     63     : Context(context), DefaultFPMathTag(FPMathTag), FMF() {
     64     ClearInsertionPoint();
     65   }
     66 
     67   //===--------------------------------------------------------------------===//
     68   // Builder configuration methods
     69   //===--------------------------------------------------------------------===//
     70 
     71   /// \brief Clear the insertion point: created instructions will not be
     72   /// inserted into a block.
     73   void ClearInsertionPoint() {
     74     BB = nullptr;
     75     InsertPt = nullptr;
     76   }
     77 
     78   BasicBlock *GetInsertBlock() const { return BB; }
     79   BasicBlock::iterator GetInsertPoint() const { return InsertPt; }
     80   LLVMContext &getContext() const { return Context; }
     81 
     82   /// \brief This specifies that created instructions should be appended to the
     83   /// end of the specified block.
     84   void SetInsertPoint(BasicBlock *TheBB) {
     85     BB = TheBB;
     86     InsertPt = BB->end();
     87   }
     88 
     89   /// \brief This specifies that created instructions should be inserted before
     90   /// the specified instruction.
     91   void SetInsertPoint(Instruction *I) {
     92     BB = I->getParent();
     93     InsertPt = I;
     94     assert(I != BB->end() && "Can't read debug loc from end()");
     95     SetCurrentDebugLocation(I->getDebugLoc());
     96   }
     97 
     98   /// \brief This specifies that created instructions should be inserted at the
     99   /// specified point.
    100   void SetInsertPoint(BasicBlock *TheBB, BasicBlock::iterator IP) {
    101     BB = TheBB;
    102     InsertPt = IP;
    103   }
    104 
    105   /// \brief Find the nearest point that dominates this use, and specify that
    106   /// created instructions should be inserted at this point.
    107   void SetInsertPoint(Use &U) {
    108     Instruction *UseInst = cast<Instruction>(U.getUser());
    109     if (PHINode *Phi = dyn_cast<PHINode>(UseInst)) {
    110       BasicBlock *PredBB = Phi->getIncomingBlock(U);
    111       assert(U != PredBB->getTerminator() && "critical edge not split");
    112       SetInsertPoint(PredBB, PredBB->getTerminator());
    113       return;
    114     }
    115     SetInsertPoint(UseInst);
    116   }
    117 
    118   /// \brief Set location information used by debugging information.
    119   void SetCurrentDebugLocation(DebugLoc L) { CurDbgLocation = std::move(L); }
    120 
    121   /// \brief Get location information used by debugging information.
    122   const DebugLoc &getCurrentDebugLocation() const { return CurDbgLocation; }
    123 
    124   /// \brief If this builder has a current debug location, set it on the
    125   /// specified instruction.
    126   void SetInstDebugLocation(Instruction *I) const {
    127     if (CurDbgLocation)
    128       I->setDebugLoc(CurDbgLocation);
    129   }
    130 
    131   /// \brief Get the return type of the current function that we're emitting
    132   /// into.
    133   Type *getCurrentFunctionReturnType() const;
    134 
    135   /// InsertPoint - A saved insertion point.
    136   class InsertPoint {
    137     BasicBlock *Block;
    138     BasicBlock::iterator Point;
    139 
    140   public:
    141     /// \brief Creates a new insertion point which doesn't point to anything.
    142     InsertPoint() : Block(nullptr) {}
    143 
    144     /// \brief Creates a new insertion point at the given location.
    145     InsertPoint(BasicBlock *InsertBlock, BasicBlock::iterator InsertPoint)
    146       : Block(InsertBlock), Point(InsertPoint) {}
    147 
    148     /// \brief Returns true if this insert point is set.
    149     bool isSet() const { return (Block != nullptr); }
    150 
    151     llvm::BasicBlock *getBlock() const { return Block; }
    152     llvm::BasicBlock::iterator getPoint() const { return Point; }
    153   };
    154 
    155   /// \brief Returns the current insert point.
    156   InsertPoint saveIP() const {
    157     return InsertPoint(GetInsertBlock(), GetInsertPoint());
    158   }
    159 
    160   /// \brief Returns the current insert point, clearing it in the process.
    161   InsertPoint saveAndClearIP() {
    162     InsertPoint IP(GetInsertBlock(), GetInsertPoint());
    163     ClearInsertionPoint();
    164     return IP;
    165   }
    166 
    167   /// \brief Sets the current insert point to a previously-saved location.
    168   void restoreIP(InsertPoint IP) {
    169     if (IP.isSet())
    170       SetInsertPoint(IP.getBlock(), IP.getPoint());
    171     else
    172       ClearInsertionPoint();
    173   }
    174 
    175   /// \brief Get the floating point math metadata being used.
    176   MDNode *getDefaultFPMathTag() const { return DefaultFPMathTag; }
    177 
    178   /// \brief Get the flags to be applied to created floating point ops
    179   FastMathFlags getFastMathFlags() const { return FMF; }
    180 
    181   /// \brief Clear the fast-math flags.
    182   void clearFastMathFlags() { FMF.clear(); }
    183 
    184   /// \brief Set the floating point math metadata to be used.
    185   void SetDefaultFPMathTag(MDNode *FPMathTag) { DefaultFPMathTag = FPMathTag; }
    186 
    187   /// \brief Set the fast-math flags to be used with generated fp-math operators
    188   void SetFastMathFlags(FastMathFlags NewFMF) { FMF = NewFMF; }
    189 
    190   //===--------------------------------------------------------------------===//
    191   // RAII helpers.
    192   //===--------------------------------------------------------------------===//
    193 
    194   // \brief RAII object that stores the current insertion point and restores it
    195   // when the object is destroyed. This includes the debug location.
    196   class InsertPointGuard {
    197     IRBuilderBase &Builder;
    198     AssertingVH<BasicBlock> Block;
    199     BasicBlock::iterator Point;
    200     DebugLoc DbgLoc;
    201 
    202     InsertPointGuard(const InsertPointGuard &) = delete;
    203     InsertPointGuard &operator=(const InsertPointGuard &) = delete;
    204 
    205   public:
    206     InsertPointGuard(IRBuilderBase &B)
    207         : Builder(B), Block(B.GetInsertBlock()), Point(B.GetInsertPoint()),
    208           DbgLoc(B.getCurrentDebugLocation()) {}
    209 
    210     ~InsertPointGuard() {
    211       Builder.restoreIP(InsertPoint(Block, Point));
    212       Builder.SetCurrentDebugLocation(DbgLoc);
    213     }
    214   };
    215 
    216   // \brief RAII object that stores the current fast math settings and restores
    217   // them when the object is destroyed.
    218   class FastMathFlagGuard {
    219     IRBuilderBase &Builder;
    220     FastMathFlags FMF;
    221     MDNode *FPMathTag;
    222 
    223     FastMathFlagGuard(const FastMathFlagGuard &) = delete;
    224     FastMathFlagGuard &operator=(
    225         const FastMathFlagGuard &) = delete;
    226 
    227   public:
    228     FastMathFlagGuard(IRBuilderBase &B)
    229         : Builder(B), FMF(B.FMF), FPMathTag(B.DefaultFPMathTag) {}
    230 
    231     ~FastMathFlagGuard() {
    232       Builder.FMF = FMF;
    233       Builder.DefaultFPMathTag = FPMathTag;
    234     }
    235   };
    236 
    237   //===--------------------------------------------------------------------===//
    238   // Miscellaneous creation methods.
    239   //===--------------------------------------------------------------------===//
    240 
    241   /// \brief Make a new global variable with initializer type i8*
    242   ///
    243   /// Make a new global variable with an initializer that has array of i8 type
    244   /// filled in with the null terminated string value specified.  The new global
    245   /// variable will be marked mergable with any others of the same contents.  If
    246   /// Name is specified, it is the name of the global variable created.
    247   GlobalVariable *CreateGlobalString(StringRef Str, const Twine &Name = "");
    248 
    249   /// \brief Get a constant value representing either true or false.
    250   ConstantInt *getInt1(bool V) {
    251     return ConstantInt::get(getInt1Ty(), V);
    252   }
    253 
    254   /// \brief Get the constant value for i1 true.
    255   ConstantInt *getTrue() {
    256     return ConstantInt::getTrue(Context);
    257   }
    258 
    259   /// \brief Get the constant value for i1 false.
    260   ConstantInt *getFalse() {
    261     return ConstantInt::getFalse(Context);
    262   }
    263 
    264   /// \brief Get a constant 8-bit value.
    265   ConstantInt *getInt8(uint8_t C) {
    266     return ConstantInt::get(getInt8Ty(), C);
    267   }
    268 
    269   /// \brief Get a constant 16-bit value.
    270   ConstantInt *getInt16(uint16_t C) {
    271     return ConstantInt::get(getInt16Ty(), C);
    272   }
    273 
    274   /// \brief Get a constant 32-bit value.
    275   ConstantInt *getInt32(uint32_t C) {
    276     return ConstantInt::get(getInt32Ty(), C);
    277   }
    278 
    279   /// \brief Get a constant 64-bit value.
    280   ConstantInt *getInt64(uint64_t C) {
    281     return ConstantInt::get(getInt64Ty(), C);
    282   }
    283 
    284   /// \brief Get a constant N-bit value, zero extended or truncated from
    285   /// a 64-bit value.
    286   ConstantInt *getIntN(unsigned N, uint64_t C) {
    287     return ConstantInt::get(getIntNTy(N), C);
    288   }
    289 
    290   /// \brief Get a constant integer value.
    291   ConstantInt *getInt(const APInt &AI) {
    292     return ConstantInt::get(Context, AI);
    293   }
    294 
    295   //===--------------------------------------------------------------------===//
    296   // Type creation methods
    297   //===--------------------------------------------------------------------===//
    298 
    299   /// \brief Fetch the type representing a single bit
    300   IntegerType *getInt1Ty() {
    301     return Type::getInt1Ty(Context);
    302   }
    303 
    304   /// \brief Fetch the type representing an 8-bit integer.
    305   IntegerType *getInt8Ty() {
    306     return Type::getInt8Ty(Context);
    307   }
    308 
    309   /// \brief Fetch the type representing a 16-bit integer.
    310   IntegerType *getInt16Ty() {
    311     return Type::getInt16Ty(Context);
    312   }
    313 
    314   /// \brief Fetch the type representing a 32-bit integer.
    315   IntegerType *getInt32Ty() {
    316     return Type::getInt32Ty(Context);
    317   }
    318 
    319   /// \brief Fetch the type representing a 64-bit integer.
    320   IntegerType *getInt64Ty() {
    321     return Type::getInt64Ty(Context);
    322   }
    323 
    324   /// \brief Fetch the type representing an N-bit integer.
    325   IntegerType *getIntNTy(unsigned N) {
    326     return Type::getIntNTy(Context, N);
    327   }
    328 
    329   /// \brief Fetch the type representing a 16-bit floating point value.
    330   Type *getHalfTy() {
    331     return Type::getHalfTy(Context);
    332   }
    333 
    334   /// \brief Fetch the type representing a 32-bit floating point value.
    335   Type *getFloatTy() {
    336     return Type::getFloatTy(Context);
    337   }
    338 
    339   /// \brief Fetch the type representing a 64-bit floating point value.
    340   Type *getDoubleTy() {
    341     return Type::getDoubleTy(Context);
    342   }
    343 
    344   /// \brief Fetch the type representing void.
    345   Type *getVoidTy() {
    346     return Type::getVoidTy(Context);
    347   }
    348 
    349   /// \brief Fetch the type representing a pointer to an 8-bit integer value.
    350   PointerType *getInt8PtrTy(unsigned AddrSpace = 0) {
    351     return Type::getInt8PtrTy(Context, AddrSpace);
    352   }
    353 
    354   /// \brief Fetch the type representing a pointer to an integer value.
    355   IntegerType *getIntPtrTy(const DataLayout &DL, unsigned AddrSpace = 0) {
    356     return DL.getIntPtrType(Context, AddrSpace);
    357   }
    358 
    359   //===--------------------------------------------------------------------===//
    360   // Intrinsic creation methods
    361   //===--------------------------------------------------------------------===//
    362 
    363   /// \brief Create and insert a memset to the specified pointer and the
    364   /// specified value.
    365   ///
    366   /// If the pointer isn't an i8*, it will be converted. If a TBAA tag is
    367   /// specified, it will be added to the instruction. Likewise with alias.scope
    368   /// and noalias tags.
    369   CallInst *CreateMemSet(Value *Ptr, Value *Val, uint64_t Size, unsigned Align,
    370                          bool isVolatile = false, MDNode *TBAATag = nullptr,
    371                          MDNode *ScopeTag = nullptr,
    372                          MDNode *NoAliasTag = nullptr) {
    373     return CreateMemSet(Ptr, Val, getInt64(Size), Align, isVolatile,
    374                         TBAATag, ScopeTag, NoAliasTag);
    375   }
    376 
    377   CallInst *CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align,
    378                          bool isVolatile = false, MDNode *TBAATag = nullptr,
    379                          MDNode *ScopeTag = nullptr,
    380                          MDNode *NoAliasTag = nullptr);
    381 
    382   /// \brief Create and insert a memcpy between the specified pointers.
    383   ///
    384   /// If the pointers aren't i8*, they will be converted.  If a TBAA tag is
    385   /// specified, it will be added to the instruction. Likewise with alias.scope
    386   /// and noalias tags.
    387   CallInst *CreateMemCpy(Value *Dst, Value *Src, uint64_t Size, unsigned Align,
    388                          bool isVolatile = false, MDNode *TBAATag = nullptr,
    389                          MDNode *TBAAStructTag = nullptr,
    390                          MDNode *ScopeTag = nullptr,
    391                          MDNode *NoAliasTag = nullptr) {
    392     return CreateMemCpy(Dst, Src, getInt64(Size), Align, isVolatile, TBAATag,
    393                         TBAAStructTag, ScopeTag, NoAliasTag);
    394   }
    395 
    396   CallInst *CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align,
    397                          bool isVolatile = false, MDNode *TBAATag = nullptr,
    398                          MDNode *TBAAStructTag = nullptr,
    399                          MDNode *ScopeTag = nullptr,
    400                          MDNode *NoAliasTag = nullptr);
    401 
    402   /// \brief Create and insert a memmove between the specified
    403   /// pointers.
    404   ///
    405   /// If the pointers aren't i8*, they will be converted.  If a TBAA tag is
    406   /// specified, it will be added to the instruction. Likewise with alias.scope
    407   /// and noalias tags.
    408   CallInst *CreateMemMove(Value *Dst, Value *Src, uint64_t Size, unsigned Align,
    409                           bool isVolatile = false, MDNode *TBAATag = nullptr,
    410                           MDNode *ScopeTag = nullptr,
    411                           MDNode *NoAliasTag = nullptr) {
    412     return CreateMemMove(Dst, Src, getInt64(Size), Align, isVolatile,
    413                          TBAATag, ScopeTag, NoAliasTag);
    414   }
    415 
    416   CallInst *CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align,
    417                           bool isVolatile = false, MDNode *TBAATag = nullptr,
    418                           MDNode *ScopeTag = nullptr,
    419                           MDNode *NoAliasTag = nullptr);
    420 
    421   /// \brief Create a lifetime.start intrinsic.
    422   ///
    423   /// If the pointer isn't i8* it will be converted.
    424   CallInst *CreateLifetimeStart(Value *Ptr, ConstantInt *Size = nullptr);
    425 
    426   /// \brief Create a lifetime.end intrinsic.
    427   ///
    428   /// If the pointer isn't i8* it will be converted.
    429   CallInst *CreateLifetimeEnd(Value *Ptr, ConstantInt *Size = nullptr);
    430 
    431   /// \brief Create a call to Masked Load intrinsic
    432   CallInst *CreateMaskedLoad(Value *Ptr, unsigned Align, Value *Mask,
    433                              Value *PassThru = 0, const Twine &Name = "");
    434 
    435   /// \brief Create a call to Masked Store intrinsic
    436   CallInst *CreateMaskedStore(Value *Val, Value *Ptr, unsigned Align,
    437                               Value *Mask);
    438 
    439   /// \brief Create an assume intrinsic call that allows the optimizer to
    440   /// assume that the provided condition will be true.
    441   CallInst *CreateAssumption(Value *Cond);
    442 
    443   /// \brief Create a call to the experimental.gc.statepoint intrinsic to
    444   /// start a new statepoint sequence.
    445   CallInst *CreateGCStatepoint(Value *ActualCallee,
    446                                ArrayRef<Value *> CallArgs,
    447                                ArrayRef<Value *> DeoptArgs,
    448                                ArrayRef<Value *> GCArgs,
    449                                const Twine &Name = "");
    450 
    451   // Conveninence function for the common case when CallArgs are filled in using
    452   // makeArrayRef(CS.arg_begin(), .arg_end()); Use needs to be .get()'ed to get
    453   // the Value *.
    454   CallInst *CreateGCStatepoint(Value *ActualCallee, ArrayRef<Use> CallArgs,
    455                                ArrayRef<Value *> DeoptArgs,
    456                                ArrayRef<Value *> GCArgs,
    457                                const Twine &Name = "");
    458 
    459   /// \brief Create a call to the experimental.gc.result intrinsic to extract
    460   /// the result from a call wrapped in a statepoint.
    461   CallInst *CreateGCResult(Instruction *Statepoint,
    462                            Type *ResultType,
    463                            const Twine &Name = "");
    464 
    465   /// \brief Create a call to the experimental.gc.relocate intrinsics to
    466   /// project the relocated value of one pointer from the statepoint.
    467   CallInst *CreateGCRelocate(Instruction *Statepoint,
    468                              int BaseOffset,
    469                              int DerivedOffset,
    470                              Type *ResultType,
    471                              const Twine &Name = "");
    472 
    473 private:
    474   /// \brief Create a call to a masked intrinsic with given Id.
    475   /// Masked intrinsic has only one overloaded type - data type.
    476   CallInst *CreateMaskedIntrinsic(unsigned Id, ArrayRef<Value *> Ops,
    477                                   Type *DataTy, const Twine &Name = "");
    478 
    479   Value *getCastedInt8PtrValue(Value *Ptr);
    480 };
    481 
    482 /// \brief This provides a uniform API for creating instructions and inserting
    483 /// them into a basic block: either at the end of a BasicBlock, or at a specific
    484 /// iterator location in a block.
    485 ///
    486 /// Note that the builder does not expose the full generality of LLVM
    487 /// instructions.  For access to extra instruction properties, use the mutators
    488 /// (e.g. setVolatile) on the instructions after they have been
    489 /// created. Convenience state exists to specify fast-math flags and fp-math
    490 /// tags.
    491 ///
    492 /// The first template argument handles whether or not to preserve names in the
    493 /// final instruction output. This defaults to on.  The second template argument
    494 /// specifies a class to use for creating constants.  This defaults to creating
    495 /// minimally folded constants.  The third template argument allows clients to
    496 /// specify custom insertion hooks that are called on every newly created
    497 /// insertion.
    498 template<bool preserveNames = true, typename T = ConstantFolder,
    499          typename Inserter = IRBuilderDefaultInserter<preserveNames> >
    500 class IRBuilder : public IRBuilderBase, public Inserter {
    501   T Folder;
    502 public:
    503   IRBuilder(LLVMContext &C, const T &F, const Inserter &I = Inserter(),
    504             MDNode *FPMathTag = nullptr)
    505     : IRBuilderBase(C, FPMathTag), Inserter(I), Folder(F) {
    506   }
    507 
    508   explicit IRBuilder(LLVMContext &C, MDNode *FPMathTag = nullptr)
    509     : IRBuilderBase(C, FPMathTag), Folder() {
    510   }
    511 
    512   explicit IRBuilder(BasicBlock *TheBB, const T &F, MDNode *FPMathTag = nullptr)
    513     : IRBuilderBase(TheBB->getContext(), FPMathTag), Folder(F) {
    514     SetInsertPoint(TheBB);
    515   }
    516 
    517   explicit IRBuilder(BasicBlock *TheBB, MDNode *FPMathTag = nullptr)
    518     : IRBuilderBase(TheBB->getContext(), FPMathTag), Folder() {
    519     SetInsertPoint(TheBB);
    520   }
    521 
    522   explicit IRBuilder(Instruction *IP, MDNode *FPMathTag = nullptr)
    523     : IRBuilderBase(IP->getContext(), FPMathTag), Folder() {
    524     SetInsertPoint(IP);
    525     SetCurrentDebugLocation(IP->getDebugLoc());
    526   }
    527 
    528   explicit IRBuilder(Use &U, MDNode *FPMathTag = nullptr)
    529     : IRBuilderBase(U->getContext(), FPMathTag), Folder() {
    530     SetInsertPoint(U);
    531     SetCurrentDebugLocation(cast<Instruction>(U.getUser())->getDebugLoc());
    532   }
    533 
    534   IRBuilder(BasicBlock *TheBB, BasicBlock::iterator IP, const T& F,
    535             MDNode *FPMathTag = nullptr)
    536     : IRBuilderBase(TheBB->getContext(), FPMathTag), Folder(F) {
    537     SetInsertPoint(TheBB, IP);
    538   }
    539 
    540   IRBuilder(BasicBlock *TheBB, BasicBlock::iterator IP,
    541             MDNode *FPMathTag = nullptr)
    542     : IRBuilderBase(TheBB->getContext(), FPMathTag), Folder() {
    543     SetInsertPoint(TheBB, IP);
    544   }
    545 
    546   /// \brief Get the constant folder being used.
    547   const T &getFolder() { return Folder; }
    548 
    549   /// \brief Return true if this builder is configured to actually add the
    550   /// requested names to IR created through it.
    551   bool isNamePreserving() const { return preserveNames; }
    552 
    553   /// \brief Insert and return the specified instruction.
    554   template<typename InstTy>
    555   InstTy *Insert(InstTy *I, const Twine &Name = "") const {
    556     this->InsertHelper(I, Name, BB, InsertPt);
    557     this->SetInstDebugLocation(I);
    558     return I;
    559   }
    560 
    561   /// \brief No-op overload to handle constants.
    562   Constant *Insert(Constant *C, const Twine& = "") const {
    563     return C;
    564   }
    565 
    566   //===--------------------------------------------------------------------===//
    567   // Instruction creation methods: Terminators
    568   //===--------------------------------------------------------------------===//
    569 
    570 private:
    571   /// \brief Helper to add branch weight metadata onto an instruction.
    572   /// \returns The annotated instruction.
    573   template <typename InstTy>
    574   InstTy *addBranchWeights(InstTy *I, MDNode *Weights) {
    575     if (Weights)
    576       I->setMetadata(LLVMContext::MD_prof, Weights);
    577     return I;
    578   }
    579 
    580 public:
    581   /// \brief Create a 'ret void' instruction.
    582   ReturnInst *CreateRetVoid() {
    583     return Insert(ReturnInst::Create(Context));
    584   }
    585 
    586   /// \brief Create a 'ret <val>' instruction.
    587   ReturnInst *CreateRet(Value *V) {
    588     return Insert(ReturnInst::Create(Context, V));
    589   }
    590 
    591   /// \brief Create a sequence of N insertvalue instructions,
    592   /// with one Value from the retVals array each, that build a aggregate
    593   /// return value one value at a time, and a ret instruction to return
    594   /// the resulting aggregate value.
    595   ///
    596   /// This is a convenience function for code that uses aggregate return values
    597   /// as a vehicle for having multiple return values.
    598   ReturnInst *CreateAggregateRet(Value *const *retVals, unsigned N) {
    599     Value *V = UndefValue::get(getCurrentFunctionReturnType());
    600     for (unsigned i = 0; i != N; ++i)
    601       V = CreateInsertValue(V, retVals[i], i, "mrv");
    602     return Insert(ReturnInst::Create(Context, V));
    603   }
    604 
    605   /// \brief Create an unconditional 'br label X' instruction.
    606   BranchInst *CreateBr(BasicBlock *Dest) {
    607     return Insert(BranchInst::Create(Dest));
    608   }
    609 
    610   /// \brief Create a conditional 'br Cond, TrueDest, FalseDest'
    611   /// instruction.
    612   BranchInst *CreateCondBr(Value *Cond, BasicBlock *True, BasicBlock *False,
    613                            MDNode *BranchWeights = nullptr) {
    614     return Insert(addBranchWeights(BranchInst::Create(True, False, Cond),
    615                                    BranchWeights));
    616   }
    617 
    618   /// \brief Create a switch instruction with the specified value, default dest,
    619   /// and with a hint for the number of cases that will be added (for efficient
    620   /// allocation).
    621   SwitchInst *CreateSwitch(Value *V, BasicBlock *Dest, unsigned NumCases = 10,
    622                            MDNode *BranchWeights = nullptr) {
    623     return Insert(addBranchWeights(SwitchInst::Create(V, Dest, NumCases),
    624                                    BranchWeights));
    625   }
    626 
    627   /// \brief Create an indirect branch instruction with the specified address
    628   /// operand, with an optional hint for the number of destinations that will be
    629   /// added (for efficient allocation).
    630   IndirectBrInst *CreateIndirectBr(Value *Addr, unsigned NumDests = 10) {
    631     return Insert(IndirectBrInst::Create(Addr, NumDests));
    632   }
    633 
    634   InvokeInst *CreateInvoke(Value *Callee, BasicBlock *NormalDest,
    635                            BasicBlock *UnwindDest, const Twine &Name = "") {
    636     return Insert(InvokeInst::Create(Callee, NormalDest, UnwindDest, None),
    637                   Name);
    638   }
    639   InvokeInst *CreateInvoke(Value *Callee, BasicBlock *NormalDest,
    640                            BasicBlock *UnwindDest, Value *Arg1,
    641                            const Twine &Name = "") {
    642     return Insert(InvokeInst::Create(Callee, NormalDest, UnwindDest, Arg1),
    643                   Name);
    644   }
    645   InvokeInst *CreateInvoke3(Value *Callee, BasicBlock *NormalDest,
    646                             BasicBlock *UnwindDest, Value *Arg1,
    647                             Value *Arg2, Value *Arg3,
    648                             const Twine &Name = "") {
    649     Value *Args[] = { Arg1, Arg2, Arg3 };
    650     return Insert(InvokeInst::Create(Callee, NormalDest, UnwindDest, Args),
    651                   Name);
    652   }
    653   /// \brief Create an invoke instruction.
    654   InvokeInst *CreateInvoke(Value *Callee, BasicBlock *NormalDest,
    655                            BasicBlock *UnwindDest, ArrayRef<Value *> Args,
    656                            const Twine &Name = "") {
    657     return Insert(InvokeInst::Create(Callee, NormalDest, UnwindDest, Args),
    658                   Name);
    659   }
    660 
    661   ResumeInst *CreateResume(Value *Exn) {
    662     return Insert(ResumeInst::Create(Exn));
    663   }
    664 
    665   UnreachableInst *CreateUnreachable() {
    666     return Insert(new UnreachableInst(Context));
    667   }
    668 
    669   //===--------------------------------------------------------------------===//
    670   // Instruction creation methods: Binary Operators
    671   //===--------------------------------------------------------------------===//
    672 private:
    673   BinaryOperator *CreateInsertNUWNSWBinOp(BinaryOperator::BinaryOps Opc,
    674                                           Value *LHS, Value *RHS,
    675                                           const Twine &Name,
    676                                           bool HasNUW, bool HasNSW) {
    677     BinaryOperator *BO = Insert(BinaryOperator::Create(Opc, LHS, RHS), Name);
    678     if (HasNUW) BO->setHasNoUnsignedWrap();
    679     if (HasNSW) BO->setHasNoSignedWrap();
    680     return BO;
    681   }
    682 
    683   Instruction *AddFPMathAttributes(Instruction *I,
    684                                    MDNode *FPMathTag,
    685                                    FastMathFlags FMF) const {
    686     if (!FPMathTag)
    687       FPMathTag = DefaultFPMathTag;
    688     if (FPMathTag)
    689       I->setMetadata(LLVMContext::MD_fpmath, FPMathTag);
    690     I->setFastMathFlags(FMF);
    691     return I;
    692   }
    693 public:
    694   Value *CreateAdd(Value *LHS, Value *RHS, const Twine &Name = "",
    695                    bool HasNUW = false, bool HasNSW = false) {
    696     if (Constant *LC = dyn_cast<Constant>(LHS))
    697       if (Constant *RC = dyn_cast<Constant>(RHS))
    698         return Insert(Folder.CreateAdd(LC, RC, HasNUW, HasNSW), Name);
    699     return CreateInsertNUWNSWBinOp(Instruction::Add, LHS, RHS, Name,
    700                                    HasNUW, HasNSW);
    701   }
    702   Value *CreateNSWAdd(Value *LHS, Value *RHS, const Twine &Name = "") {
    703     return CreateAdd(LHS, RHS, Name, false, true);
    704   }
    705   Value *CreateNUWAdd(Value *LHS, Value *RHS, const Twine &Name = "") {
    706     return CreateAdd(LHS, RHS, Name, true, false);
    707   }
    708   Value *CreateFAdd(Value *LHS, Value *RHS, const Twine &Name = "",
    709                     MDNode *FPMathTag = nullptr) {
    710     if (Constant *LC = dyn_cast<Constant>(LHS))
    711       if (Constant *RC = dyn_cast<Constant>(RHS))
    712         return Insert(Folder.CreateFAdd(LC, RC), Name);
    713     return Insert(AddFPMathAttributes(BinaryOperator::CreateFAdd(LHS, RHS),
    714                                       FPMathTag, FMF), Name);
    715   }
    716   Value *CreateSub(Value *LHS, Value *RHS, const Twine &Name = "",
    717                    bool HasNUW = false, bool HasNSW = false) {
    718     if (Constant *LC = dyn_cast<Constant>(LHS))
    719       if (Constant *RC = dyn_cast<Constant>(RHS))
    720         return Insert(Folder.CreateSub(LC, RC, HasNUW, HasNSW), Name);
    721     return CreateInsertNUWNSWBinOp(Instruction::Sub, LHS, RHS, Name,
    722                                    HasNUW, HasNSW);
    723   }
    724   Value *CreateNSWSub(Value *LHS, Value *RHS, const Twine &Name = "") {
    725     return CreateSub(LHS, RHS, Name, false, true);
    726   }
    727   Value *CreateNUWSub(Value *LHS, Value *RHS, const Twine &Name = "") {
    728     return CreateSub(LHS, RHS, Name, true, false);
    729   }
    730   Value *CreateFSub(Value *LHS, Value *RHS, const Twine &Name = "",
    731                     MDNode *FPMathTag = nullptr) {
    732     if (Constant *LC = dyn_cast<Constant>(LHS))
    733       if (Constant *RC = dyn_cast<Constant>(RHS))
    734         return Insert(Folder.CreateFSub(LC, RC), Name);
    735     return Insert(AddFPMathAttributes(BinaryOperator::CreateFSub(LHS, RHS),
    736                                       FPMathTag, FMF), Name);
    737   }
    738   Value *CreateMul(Value *LHS, Value *RHS, const Twine &Name = "",
    739                    bool HasNUW = false, bool HasNSW = false) {
    740     if (Constant *LC = dyn_cast<Constant>(LHS))
    741       if (Constant *RC = dyn_cast<Constant>(RHS))
    742         return Insert(Folder.CreateMul(LC, RC, HasNUW, HasNSW), Name);
    743     return CreateInsertNUWNSWBinOp(Instruction::Mul, LHS, RHS, Name,
    744                                    HasNUW, HasNSW);
    745   }
    746   Value *CreateNSWMul(Value *LHS, Value *RHS, const Twine &Name = "") {
    747     return CreateMul(LHS, RHS, Name, false, true);
    748   }
    749   Value *CreateNUWMul(Value *LHS, Value *RHS, const Twine &Name = "") {
    750     return CreateMul(LHS, RHS, Name, true, false);
    751   }
    752   Value *CreateFMul(Value *LHS, Value *RHS, const Twine &Name = "",
    753                     MDNode *FPMathTag = nullptr) {
    754     if (Constant *LC = dyn_cast<Constant>(LHS))
    755       if (Constant *RC = dyn_cast<Constant>(RHS))
    756         return Insert(Folder.CreateFMul(LC, RC), Name);
    757     return Insert(AddFPMathAttributes(BinaryOperator::CreateFMul(LHS, RHS),
    758                                       FPMathTag, FMF), Name);
    759   }
    760   Value *CreateUDiv(Value *LHS, Value *RHS, const Twine &Name = "",
    761                     bool isExact = false) {
    762     if (Constant *LC = dyn_cast<Constant>(LHS))
    763       if (Constant *RC = dyn_cast<Constant>(RHS))
    764         return Insert(Folder.CreateUDiv(LC, RC, isExact), Name);
    765     if (!isExact)
    766       return Insert(BinaryOperator::CreateUDiv(LHS, RHS), Name);
    767     return Insert(BinaryOperator::CreateExactUDiv(LHS, RHS), Name);
    768   }
    769   Value *CreateExactUDiv(Value *LHS, Value *RHS, const Twine &Name = "") {
    770     return CreateUDiv(LHS, RHS, Name, true);
    771   }
    772   Value *CreateSDiv(Value *LHS, Value *RHS, const Twine &Name = "",
    773                     bool isExact = false) {
    774     if (Constant *LC = dyn_cast<Constant>(LHS))
    775       if (Constant *RC = dyn_cast<Constant>(RHS))
    776         return Insert(Folder.CreateSDiv(LC, RC, isExact), Name);
    777     if (!isExact)
    778       return Insert(BinaryOperator::CreateSDiv(LHS, RHS), Name);
    779     return Insert(BinaryOperator::CreateExactSDiv(LHS, RHS), Name);
    780   }
    781   Value *CreateExactSDiv(Value *LHS, Value *RHS, const Twine &Name = "") {
    782     return CreateSDiv(LHS, RHS, Name, true);
    783   }
    784   Value *CreateFDiv(Value *LHS, Value *RHS, const Twine &Name = "",
    785                     MDNode *FPMathTag = nullptr) {
    786     if (Constant *LC = dyn_cast<Constant>(LHS))
    787       if (Constant *RC = dyn_cast<Constant>(RHS))
    788         return Insert(Folder.CreateFDiv(LC, RC), Name);
    789     return Insert(AddFPMathAttributes(BinaryOperator::CreateFDiv(LHS, RHS),
    790                                       FPMathTag, FMF), Name);
    791   }
    792   Value *CreateURem(Value *LHS, Value *RHS, const Twine &Name = "") {
    793     if (Constant *LC = dyn_cast<Constant>(LHS))
    794       if (Constant *RC = dyn_cast<Constant>(RHS))
    795         return Insert(Folder.CreateURem(LC, RC), Name);
    796     return Insert(BinaryOperator::CreateURem(LHS, RHS), Name);
    797   }
    798   Value *CreateSRem(Value *LHS, Value *RHS, const Twine &Name = "") {
    799     if (Constant *LC = dyn_cast<Constant>(LHS))
    800       if (Constant *RC = dyn_cast<Constant>(RHS))
    801         return Insert(Folder.CreateSRem(LC, RC), Name);
    802     return Insert(BinaryOperator::CreateSRem(LHS, RHS), Name);
    803   }
    804   Value *CreateFRem(Value *LHS, Value *RHS, const Twine &Name = "",
    805                     MDNode *FPMathTag = nullptr) {
    806     if (Constant *LC = dyn_cast<Constant>(LHS))
    807       if (Constant *RC = dyn_cast<Constant>(RHS))
    808         return Insert(Folder.CreateFRem(LC, RC), Name);
    809     return Insert(AddFPMathAttributes(BinaryOperator::CreateFRem(LHS, RHS),
    810                                       FPMathTag, FMF), Name);
    811   }
    812 
    813   Value *CreateShl(Value *LHS, Value *RHS, const Twine &Name = "",
    814                    bool HasNUW = false, bool HasNSW = false) {
    815     if (Constant *LC = dyn_cast<Constant>(LHS))
    816       if (Constant *RC = dyn_cast<Constant>(RHS))
    817         return Insert(Folder.CreateShl(LC, RC, HasNUW, HasNSW), Name);
    818     return CreateInsertNUWNSWBinOp(Instruction::Shl, LHS, RHS, Name,
    819                                    HasNUW, HasNSW);
    820   }
    821   Value *CreateShl(Value *LHS, const APInt &RHS, const Twine &Name = "",
    822                    bool HasNUW = false, bool HasNSW = false) {
    823     return CreateShl(LHS, ConstantInt::get(LHS->getType(), RHS), Name,
    824                      HasNUW, HasNSW);
    825   }
    826   Value *CreateShl(Value *LHS, uint64_t RHS, const Twine &Name = "",
    827                    bool HasNUW = false, bool HasNSW = false) {
    828     return CreateShl(LHS, ConstantInt::get(LHS->getType(), RHS), Name,
    829                      HasNUW, HasNSW);
    830   }
    831 
    832   Value *CreateLShr(Value *LHS, Value *RHS, const Twine &Name = "",
    833                     bool isExact = false) {
    834     if (Constant *LC = dyn_cast<Constant>(LHS))
    835       if (Constant *RC = dyn_cast<Constant>(RHS))
    836         return Insert(Folder.CreateLShr(LC, RC, isExact), Name);
    837     if (!isExact)
    838       return Insert(BinaryOperator::CreateLShr(LHS, RHS), Name);
    839     return Insert(BinaryOperator::CreateExactLShr(LHS, RHS), Name);
    840   }
    841   Value *CreateLShr(Value *LHS, const APInt &RHS, const Twine &Name = "",
    842                     bool isExact = false) {
    843     return CreateLShr(LHS, ConstantInt::get(LHS->getType(), RHS), Name,isExact);
    844   }
    845   Value *CreateLShr(Value *LHS, uint64_t RHS, const Twine &Name = "",
    846                     bool isExact = false) {
    847     return CreateLShr(LHS, ConstantInt::get(LHS->getType(), RHS), Name,isExact);
    848   }
    849 
    850   Value *CreateAShr(Value *LHS, Value *RHS, const Twine &Name = "",
    851                     bool isExact = false) {
    852     if (Constant *LC = dyn_cast<Constant>(LHS))
    853       if (Constant *RC = dyn_cast<Constant>(RHS))
    854         return Insert(Folder.CreateAShr(LC, RC, isExact), Name);
    855     if (!isExact)
    856       return Insert(BinaryOperator::CreateAShr(LHS, RHS), Name);
    857     return Insert(BinaryOperator::CreateExactAShr(LHS, RHS), Name);
    858   }
    859   Value *CreateAShr(Value *LHS, const APInt &RHS, const Twine &Name = "",
    860                     bool isExact = false) {
    861     return CreateAShr(LHS, ConstantInt::get(LHS->getType(), RHS), Name,isExact);
    862   }
    863   Value *CreateAShr(Value *LHS, uint64_t RHS, const Twine &Name = "",
    864                     bool isExact = false) {
    865     return CreateAShr(LHS, ConstantInt::get(LHS->getType(), RHS), Name,isExact);
    866   }
    867 
    868   Value *CreateAnd(Value *LHS, Value *RHS, const Twine &Name = "") {
    869     if (Constant *RC = dyn_cast<Constant>(RHS)) {
    870       if (isa<ConstantInt>(RC) && cast<ConstantInt>(RC)->isAllOnesValue())
    871         return LHS;  // LHS & -1 -> LHS
    872       if (Constant *LC = dyn_cast<Constant>(LHS))
    873         return Insert(Folder.CreateAnd(LC, RC), Name);
    874     }
    875     return Insert(BinaryOperator::CreateAnd(LHS, RHS), Name);
    876   }
    877   Value *CreateAnd(Value *LHS, const APInt &RHS, const Twine &Name = "") {
    878     return CreateAnd(LHS, ConstantInt::get(LHS->getType(), RHS), Name);
    879   }
    880   Value *CreateAnd(Value *LHS, uint64_t RHS, const Twine &Name = "") {
    881     return CreateAnd(LHS, ConstantInt::get(LHS->getType(), RHS), Name);
    882   }
    883 
    884   Value *CreateOr(Value *LHS, Value *RHS, const Twine &Name = "") {
    885     if (Constant *RC = dyn_cast<Constant>(RHS)) {
    886       if (RC->isNullValue())
    887         return LHS;  // LHS | 0 -> LHS
    888       if (Constant *LC = dyn_cast<Constant>(LHS))
    889         return Insert(Folder.CreateOr(LC, RC), Name);
    890     }
    891     return Insert(BinaryOperator::CreateOr(LHS, RHS), Name);
    892   }
    893   Value *CreateOr(Value *LHS, const APInt &RHS, const Twine &Name = "") {
    894     return CreateOr(LHS, ConstantInt::get(LHS->getType(), RHS), Name);
    895   }
    896   Value *CreateOr(Value *LHS, uint64_t RHS, const Twine &Name = "") {
    897     return CreateOr(LHS, ConstantInt::get(LHS->getType(), RHS), Name);
    898   }
    899 
    900   Value *CreateXor(Value *LHS, Value *RHS, const Twine &Name = "") {
    901     if (Constant *LC = dyn_cast<Constant>(LHS))
    902       if (Constant *RC = dyn_cast<Constant>(RHS))
    903         return Insert(Folder.CreateXor(LC, RC), Name);
    904     return Insert(BinaryOperator::CreateXor(LHS, RHS), Name);
    905   }
    906   Value *CreateXor(Value *LHS, const APInt &RHS, const Twine &Name = "") {
    907     return CreateXor(LHS, ConstantInt::get(LHS->getType(), RHS), Name);
    908   }
    909   Value *CreateXor(Value *LHS, uint64_t RHS, const Twine &Name = "") {
    910     return CreateXor(LHS, ConstantInt::get(LHS->getType(), RHS), Name);
    911   }
    912 
    913   Value *CreateBinOp(Instruction::BinaryOps Opc,
    914                      Value *LHS, Value *RHS, const Twine &Name = "",
    915                      MDNode *FPMathTag = nullptr) {
    916     if (Constant *LC = dyn_cast<Constant>(LHS))
    917       if (Constant *RC = dyn_cast<Constant>(RHS))
    918         return Insert(Folder.CreateBinOp(Opc, LC, RC), Name);
    919     llvm::Instruction *BinOp = BinaryOperator::Create(Opc, LHS, RHS);
    920     if (isa<FPMathOperator>(BinOp))
    921       BinOp = AddFPMathAttributes(BinOp, FPMathTag, FMF);
    922     return Insert(BinOp, Name);
    923   }
    924 
    925   Value *CreateNeg(Value *V, const Twine &Name = "",
    926                    bool HasNUW = false, bool HasNSW = false) {
    927     if (Constant *VC = dyn_cast<Constant>(V))
    928       return Insert(Folder.CreateNeg(VC, HasNUW, HasNSW), Name);
    929     BinaryOperator *BO = Insert(BinaryOperator::CreateNeg(V), Name);
    930     if (HasNUW) BO->setHasNoUnsignedWrap();
    931     if (HasNSW) BO->setHasNoSignedWrap();
    932     return BO;
    933   }
    934   Value *CreateNSWNeg(Value *V, const Twine &Name = "") {
    935     return CreateNeg(V, Name, false, true);
    936   }
    937   Value *CreateNUWNeg(Value *V, const Twine &Name = "") {
    938     return CreateNeg(V, Name, true, false);
    939   }
    940   Value *CreateFNeg(Value *V, const Twine &Name = "",
    941                     MDNode *FPMathTag = nullptr) {
    942     if (Constant *VC = dyn_cast<Constant>(V))
    943       return Insert(Folder.CreateFNeg(VC), Name);
    944     return Insert(AddFPMathAttributes(BinaryOperator::CreateFNeg(V),
    945                                       FPMathTag, FMF), Name);
    946   }
    947   Value *CreateNot(Value *V, const Twine &Name = "") {
    948     if (Constant *VC = dyn_cast<Constant>(V))
    949       return Insert(Folder.CreateNot(VC), Name);
    950     return Insert(BinaryOperator::CreateNot(V), Name);
    951   }
    952 
    953   //===--------------------------------------------------------------------===//
    954   // Instruction creation methods: Memory Instructions
    955   //===--------------------------------------------------------------------===//
    956 
    957   AllocaInst *CreateAlloca(Type *Ty, Value *ArraySize = nullptr,
    958                            const Twine &Name = "") {
    959     return Insert(new AllocaInst(Ty, ArraySize), Name);
    960   }
    961   // \brief Provided to resolve 'CreateLoad(Ptr, "...")' correctly, instead of
    962   // converting the string to 'bool' for the isVolatile parameter.
    963   LoadInst *CreateLoad(Value *Ptr, const char *Name) {
    964     return Insert(new LoadInst(Ptr), Name);
    965   }
    966   LoadInst *CreateLoad(Value *Ptr, const Twine &Name = "") {
    967     return Insert(new LoadInst(Ptr), Name);
    968   }
    969   LoadInst *CreateLoad(Value *Ptr, bool isVolatile, const Twine &Name = "") {
    970     return Insert(new LoadInst(Ptr, nullptr, isVolatile), Name);
    971   }
    972   StoreInst *CreateStore(Value *Val, Value *Ptr, bool isVolatile = false) {
    973     return Insert(new StoreInst(Val, Ptr, isVolatile));
    974   }
    975   // \brief Provided to resolve 'CreateAlignedLoad(Ptr, Align, "...")'
    976   // correctly, instead of converting the string to 'bool' for the isVolatile
    977   // parameter.
    978   LoadInst *CreateAlignedLoad(Value *Ptr, unsigned Align, const char *Name) {
    979     LoadInst *LI = CreateLoad(Ptr, Name);
    980     LI->setAlignment(Align);
    981     return LI;
    982   }
    983   LoadInst *CreateAlignedLoad(Value *Ptr, unsigned Align,
    984                               const Twine &Name = "") {
    985     LoadInst *LI = CreateLoad(Ptr, Name);
    986     LI->setAlignment(Align);
    987     return LI;
    988   }
    989   LoadInst *CreateAlignedLoad(Value *Ptr, unsigned Align, bool isVolatile,
    990                               const Twine &Name = "") {
    991     LoadInst *LI = CreateLoad(Ptr, isVolatile, Name);
    992     LI->setAlignment(Align);
    993     return LI;
    994   }
    995   StoreInst *CreateAlignedStore(Value *Val, Value *Ptr, unsigned Align,
    996                                 bool isVolatile = false) {
    997     StoreInst *SI = CreateStore(Val, Ptr, isVolatile);
    998     SI->setAlignment(Align);
    999     return SI;
   1000   }
   1001   FenceInst *CreateFence(AtomicOrdering Ordering,
   1002                          SynchronizationScope SynchScope = CrossThread,
   1003                          const Twine &Name = "") {
   1004     return Insert(new FenceInst(Context, Ordering, SynchScope), Name);
   1005   }
   1006   AtomicCmpXchgInst *
   1007   CreateAtomicCmpXchg(Value *Ptr, Value *Cmp, Value *New,
   1008                       AtomicOrdering SuccessOrdering,
   1009                       AtomicOrdering FailureOrdering,
   1010                       SynchronizationScope SynchScope = CrossThread) {
   1011     return Insert(new AtomicCmpXchgInst(Ptr, Cmp, New, SuccessOrdering,
   1012                                         FailureOrdering, SynchScope));
   1013   }
   1014   AtomicRMWInst *CreateAtomicRMW(AtomicRMWInst::BinOp Op, Value *Ptr, Value *Val,
   1015                                  AtomicOrdering Ordering,
   1016                                SynchronizationScope SynchScope = CrossThread) {
   1017     return Insert(new AtomicRMWInst(Op, Ptr, Val, Ordering, SynchScope));
   1018   }
   1019   Value *CreateGEP(Value *Ptr, ArrayRef<Value *> IdxList,
   1020                    const Twine &Name = "") {
   1021     return CreateGEP(nullptr, Ptr, IdxList, Name);
   1022   }
   1023   Value *CreateGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList,
   1024                    const Twine &Name = "") {
   1025     if (Constant *PC = dyn_cast<Constant>(Ptr)) {
   1026       // Every index must be constant.
   1027       size_t i, e;
   1028       for (i = 0, e = IdxList.size(); i != e; ++i)
   1029         if (!isa<Constant>(IdxList[i]))
   1030           break;
   1031       if (i == e)
   1032         return Insert(Folder.CreateGetElementPtr(Ty, PC, IdxList), Name);
   1033     }
   1034     return Insert(GetElementPtrInst::Create(Ty, Ptr, IdxList), Name);
   1035   }
   1036   Value *CreateInBoundsGEP(Value *Ptr, ArrayRef<Value *> IdxList,
   1037                            const Twine &Name = "") {
   1038     return CreateInBoundsGEP(nullptr, Ptr, IdxList, Name);
   1039   }
   1040   Value *CreateInBoundsGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList,
   1041                            const Twine &Name = "") {
   1042     if (Constant *PC = dyn_cast<Constant>(Ptr)) {
   1043       // Every index must be constant.
   1044       size_t i, e;
   1045       for (i = 0, e = IdxList.size(); i != e; ++i)
   1046         if (!isa<Constant>(IdxList[i]))
   1047           break;
   1048       if (i == e)
   1049         return Insert(Folder.CreateInBoundsGetElementPtr(Ty, PC, IdxList),
   1050                       Name);
   1051     }
   1052     return Insert(GetElementPtrInst::CreateInBounds(Ty, Ptr, IdxList), Name);
   1053   }
   1054   Value *CreateGEP(Value *Ptr, Value *Idx, const Twine &Name = "") {
   1055     return CreateGEP(nullptr, Ptr, Idx, Name);
   1056   }
   1057   Value *CreateGEP(Type *Ty, Value *Ptr, Value *Idx, const Twine &Name = "") {
   1058     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1059       if (Constant *IC = dyn_cast<Constant>(Idx))
   1060         return Insert(Folder.CreateGetElementPtr(Ty, PC, IC), Name);
   1061     return Insert(GetElementPtrInst::Create(Ty, Ptr, Idx), Name);
   1062   }
   1063   Value *CreateInBoundsGEP(Type *Ty, Value *Ptr, Value *Idx,
   1064                            const Twine &Name = "") {
   1065     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1066       if (Constant *IC = dyn_cast<Constant>(Idx))
   1067         return Insert(Folder.CreateInBoundsGetElementPtr(Ty, PC, IC), Name);
   1068     return Insert(GetElementPtrInst::CreateInBounds(Ty, Ptr, Idx), Name);
   1069   }
   1070   Value *CreateConstGEP1_32(Value *Ptr, unsigned Idx0, const Twine &Name = "") {
   1071     return CreateConstGEP1_32(nullptr, Ptr, Idx0, Name);
   1072   }
   1073   Value *CreateConstGEP1_32(Type *Ty, Value *Ptr, unsigned Idx0,
   1074                             const Twine &Name = "") {
   1075     Value *Idx = ConstantInt::get(Type::getInt32Ty(Context), Idx0);
   1076 
   1077     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1078       return Insert(Folder.CreateGetElementPtr(Ty, PC, Idx), Name);
   1079 
   1080     return Insert(GetElementPtrInst::Create(Ty, Ptr, Idx), Name);
   1081   }
   1082   Value *CreateConstInBoundsGEP1_32(Type *Ty, Value *Ptr, unsigned Idx0,
   1083                                     const Twine &Name = "") {
   1084     Value *Idx = ConstantInt::get(Type::getInt32Ty(Context), Idx0);
   1085 
   1086     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1087       return Insert(Folder.CreateInBoundsGetElementPtr(Ty, PC, Idx), Name);
   1088 
   1089     return Insert(GetElementPtrInst::CreateInBounds(Ty, Ptr, Idx), Name);
   1090   }
   1091   Value *CreateConstGEP2_32(Type *Ty, Value *Ptr, unsigned Idx0, unsigned Idx1,
   1092                             const Twine &Name = "") {
   1093     Value *Idxs[] = {
   1094       ConstantInt::get(Type::getInt32Ty(Context), Idx0),
   1095       ConstantInt::get(Type::getInt32Ty(Context), Idx1)
   1096     };
   1097 
   1098     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1099       return Insert(Folder.CreateGetElementPtr(Ty, PC, Idxs), Name);
   1100 
   1101     return Insert(GetElementPtrInst::Create(Ty, Ptr, Idxs), Name);
   1102   }
   1103   Value *CreateConstInBoundsGEP2_32(Type *Ty, Value *Ptr, unsigned Idx0,
   1104                                     unsigned Idx1, const Twine &Name = "") {
   1105     Value *Idxs[] = {
   1106       ConstantInt::get(Type::getInt32Ty(Context), Idx0),
   1107       ConstantInt::get(Type::getInt32Ty(Context), Idx1)
   1108     };
   1109 
   1110     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1111       return Insert(Folder.CreateInBoundsGetElementPtr(Ty, PC, Idxs), Name);
   1112 
   1113     return Insert(GetElementPtrInst::CreateInBounds(Ty, Ptr, Idxs), Name);
   1114   }
   1115   Value *CreateConstGEP1_64(Value *Ptr, uint64_t Idx0, const Twine &Name = "") {
   1116     Value *Idx = ConstantInt::get(Type::getInt64Ty(Context), Idx0);
   1117 
   1118     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1119       return Insert(Folder.CreateGetElementPtr(nullptr, PC, Idx), Name);
   1120 
   1121     return Insert(GetElementPtrInst::Create(nullptr, Ptr, Idx), Name);
   1122   }
   1123   Value *CreateConstInBoundsGEP1_64(Value *Ptr, uint64_t Idx0,
   1124                                     const Twine &Name = "") {
   1125     Value *Idx = ConstantInt::get(Type::getInt64Ty(Context), Idx0);
   1126 
   1127     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1128       return Insert(Folder.CreateInBoundsGetElementPtr(nullptr, PC, Idx), Name);
   1129 
   1130     return Insert(GetElementPtrInst::CreateInBounds(nullptr, Ptr, Idx), Name);
   1131   }
   1132   Value *CreateConstGEP2_64(Value *Ptr, uint64_t Idx0, uint64_t Idx1,
   1133                     const Twine &Name = "") {
   1134     Value *Idxs[] = {
   1135       ConstantInt::get(Type::getInt64Ty(Context), Idx0),
   1136       ConstantInt::get(Type::getInt64Ty(Context), Idx1)
   1137     };
   1138 
   1139     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1140       return Insert(Folder.CreateGetElementPtr(nullptr, PC, Idxs), Name);
   1141 
   1142     return Insert(GetElementPtrInst::Create(nullptr, Ptr, Idxs), Name);
   1143   }
   1144   Value *CreateConstInBoundsGEP2_64(Value *Ptr, uint64_t Idx0, uint64_t Idx1,
   1145                                     const Twine &Name = "") {
   1146     Value *Idxs[] = {
   1147       ConstantInt::get(Type::getInt64Ty(Context), Idx0),
   1148       ConstantInt::get(Type::getInt64Ty(Context), Idx1)
   1149     };
   1150 
   1151     if (Constant *PC = dyn_cast<Constant>(Ptr))
   1152       return Insert(Folder.CreateInBoundsGetElementPtr(nullptr, PC, Idxs),
   1153                     Name);
   1154 
   1155     return Insert(GetElementPtrInst::CreateInBounds(nullptr, Ptr, Idxs), Name);
   1156   }
   1157   Value *CreateStructGEP(Type *Ty, Value *Ptr, unsigned Idx,
   1158                          const Twine &Name = "") {
   1159     return CreateConstInBoundsGEP2_32(Ty, Ptr, 0, Idx, Name);
   1160   }
   1161 
   1162   /// \brief Same as CreateGlobalString, but return a pointer with "i8*" type
   1163   /// instead of a pointer to array of i8.
   1164   Value *CreateGlobalStringPtr(StringRef Str, const Twine &Name = "") {
   1165     GlobalVariable *gv = CreateGlobalString(Str, Name);
   1166     Value *zero = ConstantInt::get(Type::getInt32Ty(Context), 0);
   1167     Value *Args[] = { zero, zero };
   1168     return CreateInBoundsGEP(gv->getValueType(), gv, Args, Name);
   1169   }
   1170 
   1171   //===--------------------------------------------------------------------===//
   1172   // Instruction creation methods: Cast/Conversion Operators
   1173   //===--------------------------------------------------------------------===//
   1174 
   1175   Value *CreateTrunc(Value *V, Type *DestTy, const Twine &Name = "") {
   1176     return CreateCast(Instruction::Trunc, V, DestTy, Name);
   1177   }
   1178   Value *CreateZExt(Value *V, Type *DestTy, const Twine &Name = "") {
   1179     return CreateCast(Instruction::ZExt, V, DestTy, Name);
   1180   }
   1181   Value *CreateSExt(Value *V, Type *DestTy, const Twine &Name = "") {
   1182     return CreateCast(Instruction::SExt, V, DestTy, Name);
   1183   }
   1184   /// \brief Create a ZExt or Trunc from the integer value V to DestTy. Return
   1185   /// the value untouched if the type of V is already DestTy.
   1186   Value *CreateZExtOrTrunc(Value *V, Type *DestTy,
   1187                            const Twine &Name = "") {
   1188     assert(V->getType()->isIntOrIntVectorTy() &&
   1189            DestTy->isIntOrIntVectorTy() &&
   1190            "Can only zero extend/truncate integers!");
   1191     Type *VTy = V->getType();
   1192     if (VTy->getScalarSizeInBits() < DestTy->getScalarSizeInBits())
   1193       return CreateZExt(V, DestTy, Name);
   1194     if (VTy->getScalarSizeInBits() > DestTy->getScalarSizeInBits())
   1195       return CreateTrunc(V, DestTy, Name);
   1196     return V;
   1197   }
   1198   /// \brief Create a SExt or Trunc from the integer value V to DestTy. Return
   1199   /// the value untouched if the type of V is already DestTy.
   1200   Value *CreateSExtOrTrunc(Value *V, Type *DestTy,
   1201                            const Twine &Name = "") {
   1202     assert(V->getType()->isIntOrIntVectorTy() &&
   1203            DestTy->isIntOrIntVectorTy() &&
   1204            "Can only sign extend/truncate integers!");
   1205     Type *VTy = V->getType();
   1206     if (VTy->getScalarSizeInBits() < DestTy->getScalarSizeInBits())
   1207       return CreateSExt(V, DestTy, Name);
   1208     if (VTy->getScalarSizeInBits() > DestTy->getScalarSizeInBits())
   1209       return CreateTrunc(V, DestTy, Name);
   1210     return V;
   1211   }
   1212   Value *CreateFPToUI(Value *V, Type *DestTy, const Twine &Name = ""){
   1213     return CreateCast(Instruction::FPToUI, V, DestTy, Name);
   1214   }
   1215   Value *CreateFPToSI(Value *V, Type *DestTy, const Twine &Name = ""){
   1216     return CreateCast(Instruction::FPToSI, V, DestTy, Name);
   1217   }
   1218   Value *CreateUIToFP(Value *V, Type *DestTy, const Twine &Name = ""){
   1219     return CreateCast(Instruction::UIToFP, V, DestTy, Name);
   1220   }
   1221   Value *CreateSIToFP(Value *V, Type *DestTy, const Twine &Name = ""){
   1222     return CreateCast(Instruction::SIToFP, V, DestTy, Name);
   1223   }
   1224   Value *CreateFPTrunc(Value *V, Type *DestTy,
   1225                        const Twine &Name = "") {
   1226     return CreateCast(Instruction::FPTrunc, V, DestTy, Name);
   1227   }
   1228   Value *CreateFPExt(Value *V, Type *DestTy, const Twine &Name = "") {
   1229     return CreateCast(Instruction::FPExt, V, DestTy, Name);
   1230   }
   1231   Value *CreatePtrToInt(Value *V, Type *DestTy,
   1232                         const Twine &Name = "") {
   1233     return CreateCast(Instruction::PtrToInt, V, DestTy, Name);
   1234   }
   1235   Value *CreateIntToPtr(Value *V, Type *DestTy,
   1236                         const Twine &Name = "") {
   1237     return CreateCast(Instruction::IntToPtr, V, DestTy, Name);
   1238   }
   1239   Value *CreateBitCast(Value *V, Type *DestTy,
   1240                        const Twine &Name = "") {
   1241     return CreateCast(Instruction::BitCast, V, DestTy, Name);
   1242   }
   1243   Value *CreateAddrSpaceCast(Value *V, Type *DestTy,
   1244                              const Twine &Name = "") {
   1245     return CreateCast(Instruction::AddrSpaceCast, V, DestTy, Name);
   1246   }
   1247   Value *CreateZExtOrBitCast(Value *V, Type *DestTy,
   1248                              const Twine &Name = "") {
   1249     if (V->getType() == DestTy)
   1250       return V;
   1251     if (Constant *VC = dyn_cast<Constant>(V))
   1252       return Insert(Folder.CreateZExtOrBitCast(VC, DestTy), Name);
   1253     return Insert(CastInst::CreateZExtOrBitCast(V, DestTy), Name);
   1254   }
   1255   Value *CreateSExtOrBitCast(Value *V, Type *DestTy,
   1256                              const Twine &Name = "") {
   1257     if (V->getType() == DestTy)
   1258       return V;
   1259     if (Constant *VC = dyn_cast<Constant>(V))
   1260       return Insert(Folder.CreateSExtOrBitCast(VC, DestTy), Name);
   1261     return Insert(CastInst::CreateSExtOrBitCast(V, DestTy), Name);
   1262   }
   1263   Value *CreateTruncOrBitCast(Value *V, Type *DestTy,
   1264                               const Twine &Name = "") {
   1265     if (V->getType() == DestTy)
   1266       return V;
   1267     if (Constant *VC = dyn_cast<Constant>(V))
   1268       return Insert(Folder.CreateTruncOrBitCast(VC, DestTy), Name);
   1269     return Insert(CastInst::CreateTruncOrBitCast(V, DestTy), Name);
   1270   }
   1271   Value *CreateCast(Instruction::CastOps Op, Value *V, Type *DestTy,
   1272                     const Twine &Name = "") {
   1273     if (V->getType() == DestTy)
   1274       return V;
   1275     if (Constant *VC = dyn_cast<Constant>(V))
   1276       return Insert(Folder.CreateCast(Op, VC, DestTy), Name);
   1277     return Insert(CastInst::Create(Op, V, DestTy), Name);
   1278   }
   1279   Value *CreatePointerCast(Value *V, Type *DestTy,
   1280                            const Twine &Name = "") {
   1281     if (V->getType() == DestTy)
   1282       return V;
   1283     if (Constant *VC = dyn_cast<Constant>(V))
   1284       return Insert(Folder.CreatePointerCast(VC, DestTy), Name);
   1285     return Insert(CastInst::CreatePointerCast(V, DestTy), Name);
   1286   }
   1287 
   1288   Value *CreatePointerBitCastOrAddrSpaceCast(Value *V, Type *DestTy,
   1289                                              const Twine &Name = "") {
   1290     if (V->getType() == DestTy)
   1291       return V;
   1292 
   1293     if (Constant *VC = dyn_cast<Constant>(V)) {
   1294       return Insert(Folder.CreatePointerBitCastOrAddrSpaceCast(VC, DestTy),
   1295                     Name);
   1296     }
   1297 
   1298     return Insert(CastInst::CreatePointerBitCastOrAddrSpaceCast(V, DestTy),
   1299                   Name);
   1300   }
   1301 
   1302   Value *CreateIntCast(Value *V, Type *DestTy, bool isSigned,
   1303                        const Twine &Name = "") {
   1304     if (V->getType() == DestTy)
   1305       return V;
   1306     if (Constant *VC = dyn_cast<Constant>(V))
   1307       return Insert(Folder.CreateIntCast(VC, DestTy, isSigned), Name);
   1308     return Insert(CastInst::CreateIntegerCast(V, DestTy, isSigned), Name);
   1309   }
   1310 
   1311   Value *CreateBitOrPointerCast(Value *V, Type *DestTy,
   1312                                 const Twine &Name = "") {
   1313     if (V->getType() == DestTy)
   1314       return V;
   1315     if (V->getType()->isPointerTy() && DestTy->isIntegerTy())
   1316       return CreatePtrToInt(V, DestTy, Name);
   1317     if (V->getType()->isIntegerTy() && DestTy->isPointerTy())
   1318       return CreateIntToPtr(V, DestTy, Name);
   1319 
   1320     return CreateBitCast(V, DestTy, Name);
   1321   }
   1322 private:
   1323   // \brief Provided to resolve 'CreateIntCast(Ptr, Ptr, "...")', giving a
   1324   // compile time error, instead of converting the string to bool for the
   1325   // isSigned parameter.
   1326   Value *CreateIntCast(Value *, Type *, const char *) = delete;
   1327 public:
   1328   Value *CreateFPCast(Value *V, Type *DestTy, const Twine &Name = "") {
   1329     if (V->getType() == DestTy)
   1330       return V;
   1331     if (Constant *VC = dyn_cast<Constant>(V))
   1332       return Insert(Folder.CreateFPCast(VC, DestTy), Name);
   1333     return Insert(CastInst::CreateFPCast(V, DestTy), Name);
   1334   }
   1335 
   1336   //===--------------------------------------------------------------------===//
   1337   // Instruction creation methods: Compare Instructions
   1338   //===--------------------------------------------------------------------===//
   1339 
   1340   Value *CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name = "") {
   1341     return CreateICmp(ICmpInst::ICMP_EQ, LHS, RHS, Name);
   1342   }
   1343   Value *CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1344     return CreateICmp(ICmpInst::ICMP_NE, LHS, RHS, Name);
   1345   }
   1346   Value *CreateICmpUGT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1347     return CreateICmp(ICmpInst::ICMP_UGT, LHS, RHS, Name);
   1348   }
   1349   Value *CreateICmpUGE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1350     return CreateICmp(ICmpInst::ICMP_UGE, LHS, RHS, Name);
   1351   }
   1352   Value *CreateICmpULT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1353     return CreateICmp(ICmpInst::ICMP_ULT, LHS, RHS, Name);
   1354   }
   1355   Value *CreateICmpULE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1356     return CreateICmp(ICmpInst::ICMP_ULE, LHS, RHS, Name);
   1357   }
   1358   Value *CreateICmpSGT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1359     return CreateICmp(ICmpInst::ICMP_SGT, LHS, RHS, Name);
   1360   }
   1361   Value *CreateICmpSGE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1362     return CreateICmp(ICmpInst::ICMP_SGE, LHS, RHS, Name);
   1363   }
   1364   Value *CreateICmpSLT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1365     return CreateICmp(ICmpInst::ICMP_SLT, LHS, RHS, Name);
   1366   }
   1367   Value *CreateICmpSLE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1368     return CreateICmp(ICmpInst::ICMP_SLE, LHS, RHS, Name);
   1369   }
   1370 
   1371   Value *CreateFCmpOEQ(Value *LHS, Value *RHS, const Twine &Name = "") {
   1372     return CreateFCmp(FCmpInst::FCMP_OEQ, LHS, RHS, Name);
   1373   }
   1374   Value *CreateFCmpOGT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1375     return CreateFCmp(FCmpInst::FCMP_OGT, LHS, RHS, Name);
   1376   }
   1377   Value *CreateFCmpOGE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1378     return CreateFCmp(FCmpInst::FCMP_OGE, LHS, RHS, Name);
   1379   }
   1380   Value *CreateFCmpOLT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1381     return CreateFCmp(FCmpInst::FCMP_OLT, LHS, RHS, Name);
   1382   }
   1383   Value *CreateFCmpOLE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1384     return CreateFCmp(FCmpInst::FCMP_OLE, LHS, RHS, Name);
   1385   }
   1386   Value *CreateFCmpONE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1387     return CreateFCmp(FCmpInst::FCMP_ONE, LHS, RHS, Name);
   1388   }
   1389   Value *CreateFCmpORD(Value *LHS, Value *RHS, const Twine &Name = "") {
   1390     return CreateFCmp(FCmpInst::FCMP_ORD, LHS, RHS, Name);
   1391   }
   1392   Value *CreateFCmpUNO(Value *LHS, Value *RHS, const Twine &Name = "") {
   1393     return CreateFCmp(FCmpInst::FCMP_UNO, LHS, RHS, Name);
   1394   }
   1395   Value *CreateFCmpUEQ(Value *LHS, Value *RHS, const Twine &Name = "") {
   1396     return CreateFCmp(FCmpInst::FCMP_UEQ, LHS, RHS, Name);
   1397   }
   1398   Value *CreateFCmpUGT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1399     return CreateFCmp(FCmpInst::FCMP_UGT, LHS, RHS, Name);
   1400   }
   1401   Value *CreateFCmpUGE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1402     return CreateFCmp(FCmpInst::FCMP_UGE, LHS, RHS, Name);
   1403   }
   1404   Value *CreateFCmpULT(Value *LHS, Value *RHS, const Twine &Name = "") {
   1405     return CreateFCmp(FCmpInst::FCMP_ULT, LHS, RHS, Name);
   1406   }
   1407   Value *CreateFCmpULE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1408     return CreateFCmp(FCmpInst::FCMP_ULE, LHS, RHS, Name);
   1409   }
   1410   Value *CreateFCmpUNE(Value *LHS, Value *RHS, const Twine &Name = "") {
   1411     return CreateFCmp(FCmpInst::FCMP_UNE, LHS, RHS, Name);
   1412   }
   1413 
   1414   Value *CreateICmp(CmpInst::Predicate P, Value *LHS, Value *RHS,
   1415                     const Twine &Name = "") {
   1416     if (Constant *LC = dyn_cast<Constant>(LHS))
   1417       if (Constant *RC = dyn_cast<Constant>(RHS))
   1418         return Insert(Folder.CreateICmp(P, LC, RC), Name);
   1419     return Insert(new ICmpInst(P, LHS, RHS), Name);
   1420   }
   1421   Value *CreateFCmp(CmpInst::Predicate P, Value *LHS, Value *RHS,
   1422                     const Twine &Name = "") {
   1423     if (Constant *LC = dyn_cast<Constant>(LHS))
   1424       if (Constant *RC = dyn_cast<Constant>(RHS))
   1425         return Insert(Folder.CreateFCmp(P, LC, RC), Name);
   1426     return Insert(new FCmpInst(P, LHS, RHS), Name);
   1427   }
   1428 
   1429   //===--------------------------------------------------------------------===//
   1430   // Instruction creation methods: Other Instructions
   1431   //===--------------------------------------------------------------------===//
   1432 
   1433   PHINode *CreatePHI(Type *Ty, unsigned NumReservedValues,
   1434                      const Twine &Name = "") {
   1435     return Insert(PHINode::Create(Ty, NumReservedValues), Name);
   1436   }
   1437 
   1438   CallInst *CreateCall(Value *Callee, const Twine &Name = "") {
   1439     return Insert(CallInst::Create(Callee), Name);
   1440   }
   1441   CallInst *CreateCall(Value *Callee, Value *Arg, const Twine &Name = "") {
   1442     return Insert(CallInst::Create(Callee, Arg), Name);
   1443   }
   1444   CallInst *CreateCall2(Value *Callee, Value *Arg1, Value *Arg2,
   1445                         const Twine &Name = "") {
   1446     Value *Args[] = { Arg1, Arg2 };
   1447     return Insert(CallInst::Create(Callee, Args), Name);
   1448   }
   1449   CallInst *CreateCall3(Value *Callee, Value *Arg1, Value *Arg2, Value *Arg3,
   1450                         const Twine &Name = "") {
   1451     Value *Args[] = { Arg1, Arg2, Arg3 };
   1452     return Insert(CallInst::Create(Callee, Args), Name);
   1453   }
   1454   CallInst *CreateCall4(Value *Callee, Value *Arg1, Value *Arg2, Value *Arg3,
   1455                         Value *Arg4, const Twine &Name = "") {
   1456     Value *Args[] = { Arg1, Arg2, Arg3, Arg4 };
   1457     return Insert(CallInst::Create(Callee, Args), Name);
   1458   }
   1459   CallInst *CreateCall5(Value *Callee, Value *Arg1, Value *Arg2, Value *Arg3,
   1460                         Value *Arg4, Value *Arg5, const Twine &Name = "") {
   1461     Value *Args[] = { Arg1, Arg2, Arg3, Arg4, Arg5 };
   1462     return Insert(CallInst::Create(Callee, Args), Name);
   1463   }
   1464 
   1465   CallInst *CreateCall(Value *Callee, ArrayRef<Value *> Args,
   1466                        const Twine &Name = "") {
   1467     return Insert(CallInst::Create(Callee, Args), Name);
   1468   }
   1469 
   1470   Value *CreateSelect(Value *C, Value *True, Value *False,
   1471                       const Twine &Name = "") {
   1472     if (Constant *CC = dyn_cast<Constant>(C))
   1473       if (Constant *TC = dyn_cast<Constant>(True))
   1474         if (Constant *FC = dyn_cast<Constant>(False))
   1475           return Insert(Folder.CreateSelect(CC, TC, FC), Name);
   1476     return Insert(SelectInst::Create(C, True, False), Name);
   1477   }
   1478 
   1479   VAArgInst *CreateVAArg(Value *List, Type *Ty, const Twine &Name = "") {
   1480     return Insert(new VAArgInst(List, Ty), Name);
   1481   }
   1482 
   1483   Value *CreateExtractElement(Value *Vec, Value *Idx,
   1484                               const Twine &Name = "") {
   1485     if (Constant *VC = dyn_cast<Constant>(Vec))
   1486       if (Constant *IC = dyn_cast<Constant>(Idx))
   1487         return Insert(Folder.CreateExtractElement(VC, IC), Name);
   1488     return Insert(ExtractElementInst::Create(Vec, Idx), Name);
   1489   }
   1490 
   1491   Value *CreateInsertElement(Value *Vec, Value *NewElt, Value *Idx,
   1492                              const Twine &Name = "") {
   1493     if (Constant *VC = dyn_cast<Constant>(Vec))
   1494       if (Constant *NC = dyn_cast<Constant>(NewElt))
   1495         if (Constant *IC = dyn_cast<Constant>(Idx))
   1496           return Insert(Folder.CreateInsertElement(VC, NC, IC), Name);
   1497     return Insert(InsertElementInst::Create(Vec, NewElt, Idx), Name);
   1498   }
   1499 
   1500   Value *CreateShuffleVector(Value *V1, Value *V2, Value *Mask,
   1501                              const Twine &Name = "") {
   1502     if (Constant *V1C = dyn_cast<Constant>(V1))
   1503       if (Constant *V2C = dyn_cast<Constant>(V2))
   1504         if (Constant *MC = dyn_cast<Constant>(Mask))
   1505           return Insert(Folder.CreateShuffleVector(V1C, V2C, MC), Name);
   1506     return Insert(new ShuffleVectorInst(V1, V2, Mask), Name);
   1507   }
   1508 
   1509   Value *CreateShuffleVector(Value *V1, Value *V2, ArrayRef<int> IntMask,
   1510                              const Twine &Name = "") {
   1511     size_t MaskSize = IntMask.size();
   1512     SmallVector<Constant*, 8> MaskVec(MaskSize);
   1513     for (size_t i = 0; i != MaskSize; ++i)
   1514       MaskVec[i] = getInt32(IntMask[i]);
   1515     Value *Mask = ConstantVector::get(MaskVec);
   1516     return CreateShuffleVector(V1, V2, Mask, Name);
   1517   }
   1518 
   1519   Value *CreateExtractValue(Value *Agg,
   1520                             ArrayRef<unsigned> Idxs,
   1521                             const Twine &Name = "") {
   1522     if (Constant *AggC = dyn_cast<Constant>(Agg))
   1523       return Insert(Folder.CreateExtractValue(AggC, Idxs), Name);
   1524     return Insert(ExtractValueInst::Create(Agg, Idxs), Name);
   1525   }
   1526 
   1527   Value *CreateInsertValue(Value *Agg, Value *Val,
   1528                            ArrayRef<unsigned> Idxs,
   1529                            const Twine &Name = "") {
   1530     if (Constant *AggC = dyn_cast<Constant>(Agg))
   1531       if (Constant *ValC = dyn_cast<Constant>(Val))
   1532         return Insert(Folder.CreateInsertValue(AggC, ValC, Idxs), Name);
   1533     return Insert(InsertValueInst::Create(Agg, Val, Idxs), Name);
   1534   }
   1535 
   1536   LandingPadInst *CreateLandingPad(Type *Ty, Value *PersFn, unsigned NumClauses,
   1537                                    const Twine &Name = "") {
   1538     return Insert(LandingPadInst::Create(Ty, PersFn, NumClauses), Name);
   1539   }
   1540 
   1541   //===--------------------------------------------------------------------===//
   1542   // Utility creation methods
   1543   //===--------------------------------------------------------------------===//
   1544 
   1545   /// \brief Return an i1 value testing if \p Arg is null.
   1546   Value *CreateIsNull(Value *Arg, const Twine &Name = "") {
   1547     return CreateICmpEQ(Arg, Constant::getNullValue(Arg->getType()),
   1548                         Name);
   1549   }
   1550 
   1551   /// \brief Return an i1 value testing if \p Arg is not null.
   1552   Value *CreateIsNotNull(Value *Arg, const Twine &Name = "") {
   1553     return CreateICmpNE(Arg, Constant::getNullValue(Arg->getType()),
   1554                         Name);
   1555   }
   1556 
   1557   /// \brief Return the i64 difference between two pointer values, dividing out
   1558   /// the size of the pointed-to objects.
   1559   ///
   1560   /// This is intended to implement C-style pointer subtraction. As such, the
   1561   /// pointers must be appropriately aligned for their element types and
   1562   /// pointing into the same object.
   1563   Value *CreatePtrDiff(Value *LHS, Value *RHS, const Twine &Name = "") {
   1564     assert(LHS->getType() == RHS->getType() &&
   1565            "Pointer subtraction operand types must match!");
   1566     PointerType *ArgType = cast<PointerType>(LHS->getType());
   1567     Value *LHS_int = CreatePtrToInt(LHS, Type::getInt64Ty(Context));
   1568     Value *RHS_int = CreatePtrToInt(RHS, Type::getInt64Ty(Context));
   1569     Value *Difference = CreateSub(LHS_int, RHS_int);
   1570     return CreateExactSDiv(Difference,
   1571                            ConstantExpr::getSizeOf(ArgType->getElementType()),
   1572                            Name);
   1573   }
   1574 
   1575   /// \brief Return a vector value that contains \arg V broadcasted to \p
   1576   /// NumElts elements.
   1577   Value *CreateVectorSplat(unsigned NumElts, Value *V, const Twine &Name = "") {
   1578     assert(NumElts > 0 && "Cannot splat to an empty vector!");
   1579 
   1580     // First insert it into an undef vector so we can shuffle it.
   1581     Type *I32Ty = getInt32Ty();
   1582     Value *Undef = UndefValue::get(VectorType::get(V->getType(), NumElts));
   1583     V = CreateInsertElement(Undef, V, ConstantInt::get(I32Ty, 0),
   1584                             Name + ".splatinsert");
   1585 
   1586     // Shuffle the value across the desired number of elements.
   1587     Value *Zeros = ConstantAggregateZero::get(VectorType::get(I32Ty, NumElts));
   1588     return CreateShuffleVector(V, Undef, Zeros, Name + ".splat");
   1589   }
   1590 
   1591   /// \brief Return a value that has been extracted from a larger integer type.
   1592   Value *CreateExtractInteger(const DataLayout &DL, Value *From,
   1593                               IntegerType *ExtractedTy, uint64_t Offset,
   1594                               const Twine &Name) {
   1595     IntegerType *IntTy = cast<IntegerType>(From->getType());
   1596     assert(DL.getTypeStoreSize(ExtractedTy) + Offset <=
   1597                DL.getTypeStoreSize(IntTy) &&
   1598            "Element extends past full value");
   1599     uint64_t ShAmt = 8 * Offset;
   1600     Value *V = From;
   1601     if (DL.isBigEndian())
   1602       ShAmt = 8 * (DL.getTypeStoreSize(IntTy) -
   1603                    DL.getTypeStoreSize(ExtractedTy) - Offset);
   1604     if (ShAmt) {
   1605       V = CreateLShr(V, ShAmt, Name + ".shift");
   1606     }
   1607     assert(ExtractedTy->getBitWidth() <= IntTy->getBitWidth() &&
   1608            "Cannot extract to a larger integer!");
   1609     if (ExtractedTy != IntTy) {
   1610       V = CreateTrunc(V, ExtractedTy, Name + ".trunc");
   1611     }
   1612     return V;
   1613   }
   1614 
   1615   /// \brief Create an assume intrinsic call that represents an alignment
   1616   /// assumption on the provided pointer.
   1617   ///
   1618   /// An optional offset can be provided, and if it is provided, the offset
   1619   /// must be subtracted from the provided pointer to get the pointer with the
   1620   /// specified alignment.
   1621   CallInst *CreateAlignmentAssumption(const DataLayout &DL, Value *PtrValue,
   1622                                       unsigned Alignment,
   1623                                       Value *OffsetValue = nullptr) {
   1624     assert(isa<PointerType>(PtrValue->getType()) &&
   1625            "trying to create an alignment assumption on a non-pointer?");
   1626 
   1627     PointerType *PtrTy = cast<PointerType>(PtrValue->getType());
   1628     Type *IntPtrTy = getIntPtrTy(DL, PtrTy->getAddressSpace());
   1629     Value *PtrIntValue = CreatePtrToInt(PtrValue, IntPtrTy, "ptrint");
   1630 
   1631     Value *Mask = ConstantInt::get(IntPtrTy,
   1632       Alignment > 0 ? Alignment - 1 : 0);
   1633     if (OffsetValue) {
   1634       bool IsOffsetZero = false;
   1635       if (ConstantInt *CI = dyn_cast<ConstantInt>(OffsetValue))
   1636         IsOffsetZero = CI->isZero();
   1637 
   1638       if (!IsOffsetZero) {
   1639         if (OffsetValue->getType() != IntPtrTy)
   1640           OffsetValue = CreateIntCast(OffsetValue, IntPtrTy, /*isSigned*/ true,
   1641                                       "offsetcast");
   1642         PtrIntValue = CreateSub(PtrIntValue, OffsetValue, "offsetptr");
   1643       }
   1644     }
   1645 
   1646     Value *Zero = ConstantInt::get(IntPtrTy, 0);
   1647     Value *MaskedPtr = CreateAnd(PtrIntValue, Mask, "maskedptr");
   1648     Value *InvCond = CreateICmpEQ(MaskedPtr, Zero, "maskcond");
   1649 
   1650     return CreateAssumption(InvCond);
   1651   }
   1652 };
   1653 
   1654 // Create wrappers for C Binding types (see CBindingWrapping.h).
   1655 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(IRBuilder<>, LLVMBuilderRef)
   1656 
   1657 }
   1658 
   1659 #endif
   1660