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      1 //===-- Instructions.cpp - Implement the LLVM instructions ----------------===//
      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 implements all of the non-inline methods for the LLVM instruction
     11 // classes.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "llvm/IR/Instructions.h"
     16 #include "LLVMContextImpl.h"
     17 #include "llvm/IR/CallSite.h"
     18 #include "llvm/IR/ConstantRange.h"
     19 #include "llvm/IR/Constants.h"
     20 #include "llvm/IR/DataLayout.h"
     21 #include "llvm/IR/DerivedTypes.h"
     22 #include "llvm/IR/Function.h"
     23 #include "llvm/IR/Module.h"
     24 #include "llvm/IR/Operator.h"
     25 #include "llvm/Support/ErrorHandling.h"
     26 #include "llvm/Support/MathExtras.h"
     27 using namespace llvm;
     28 
     29 //===----------------------------------------------------------------------===//
     30 //                            CallSite Class
     31 //===----------------------------------------------------------------------===//
     32 
     33 User::op_iterator CallSite::getCallee() const {
     34   Instruction *II(getInstruction());
     35   return isCall()
     36     ? cast<CallInst>(II)->op_end() - 1 // Skip Callee
     37     : cast<InvokeInst>(II)->op_end() - 3; // Skip BB, BB, Callee
     38 }
     39 
     40 //===----------------------------------------------------------------------===//
     41 //                            TerminatorInst Class
     42 //===----------------------------------------------------------------------===//
     43 
     44 // Out of line virtual method, so the vtable, etc has a home.
     45 TerminatorInst::~TerminatorInst() {
     46 }
     47 
     48 //===----------------------------------------------------------------------===//
     49 //                           UnaryInstruction Class
     50 //===----------------------------------------------------------------------===//
     51 
     52 // Out of line virtual method, so the vtable, etc has a home.
     53 UnaryInstruction::~UnaryInstruction() {
     54 }
     55 
     56 //===----------------------------------------------------------------------===//
     57 //                              SelectInst Class
     58 //===----------------------------------------------------------------------===//
     59 
     60 /// areInvalidOperands - Return a string if the specified operands are invalid
     61 /// for a select operation, otherwise return null.
     62 const char *SelectInst::areInvalidOperands(Value *Op0, Value *Op1, Value *Op2) {
     63   if (Op1->getType() != Op2->getType())
     64     return "both values to select must have same type";
     65 
     66   if (VectorType *VT = dyn_cast<VectorType>(Op0->getType())) {
     67     // Vector select.
     68     if (VT->getElementType() != Type::getInt1Ty(Op0->getContext()))
     69       return "vector select condition element type must be i1";
     70     VectorType *ET = dyn_cast<VectorType>(Op1->getType());
     71     if (!ET)
     72       return "selected values for vector select must be vectors";
     73     if (ET->getNumElements() != VT->getNumElements())
     74       return "vector select requires selected vectors to have "
     75                    "the same vector length as select condition";
     76   } else if (Op0->getType() != Type::getInt1Ty(Op0->getContext())) {
     77     return "select condition must be i1 or <n x i1>";
     78   }
     79   return nullptr;
     80 }
     81 
     82 
     83 //===----------------------------------------------------------------------===//
     84 //                               PHINode Class
     85 //===----------------------------------------------------------------------===//
     86 
     87 PHINode::PHINode(const PHINode &PN)
     88   : Instruction(PN.getType(), Instruction::PHI,
     89                 allocHungoffUses(PN.getNumOperands()), PN.getNumOperands()),
     90     ReservedSpace(PN.getNumOperands()) {
     91   std::copy(PN.op_begin(), PN.op_end(), op_begin());
     92   std::copy(PN.block_begin(), PN.block_end(), block_begin());
     93   SubclassOptionalData = PN.SubclassOptionalData;
     94 }
     95 
     96 PHINode::~PHINode() {
     97   dropHungoffUses();
     98 }
     99 
    100 Use *PHINode::allocHungoffUses(unsigned N) const {
    101   // Allocate the array of Uses of the incoming values, followed by a pointer
    102   // (with bottom bit set) to the User, followed by the array of pointers to
    103   // the incoming basic blocks.
    104   size_t size = N * sizeof(Use) + sizeof(Use::UserRef)
    105     + N * sizeof(BasicBlock*);
    106   Use *Begin = static_cast<Use*>(::operator new(size));
    107   Use *End = Begin + N;
    108   (void) new(End) Use::UserRef(const_cast<PHINode*>(this), 1);
    109   return Use::initTags(Begin, End);
    110 }
    111 
    112 // removeIncomingValue - Remove an incoming value.  This is useful if a
    113 // predecessor basic block is deleted.
    114 Value *PHINode::removeIncomingValue(unsigned Idx, bool DeletePHIIfEmpty) {
    115   Value *Removed = getIncomingValue(Idx);
    116 
    117   // Move everything after this operand down.
    118   //
    119   // FIXME: we could just swap with the end of the list, then erase.  However,
    120   // clients might not expect this to happen.  The code as it is thrashes the
    121   // use/def lists, which is kinda lame.
    122   std::copy(op_begin() + Idx + 1, op_end(), op_begin() + Idx);
    123   std::copy(block_begin() + Idx + 1, block_end(), block_begin() + Idx);
    124 
    125   // Nuke the last value.
    126   Op<-1>().set(nullptr);
    127   --NumOperands;
    128 
    129   // If the PHI node is dead, because it has zero entries, nuke it now.
    130   if (getNumOperands() == 0 && DeletePHIIfEmpty) {
    131     // If anyone is using this PHI, make them use a dummy value instead...
    132     replaceAllUsesWith(UndefValue::get(getType()));
    133     eraseFromParent();
    134   }
    135   return Removed;
    136 }
    137 
    138 /// growOperands - grow operands - This grows the operand list in response
    139 /// to a push_back style of operation.  This grows the number of ops by 1.5
    140 /// times.
    141 ///
    142 void PHINode::growOperands() {
    143   unsigned e = getNumOperands();
    144   unsigned NumOps = e + e / 2;
    145   if (NumOps < 2) NumOps = 2;      // 2 op PHI nodes are VERY common.
    146 
    147   Use *OldOps = op_begin();
    148   BasicBlock **OldBlocks = block_begin();
    149 
    150   ReservedSpace = NumOps;
    151   OperandList = allocHungoffUses(ReservedSpace);
    152 
    153   std::copy(OldOps, OldOps + e, op_begin());
    154   std::copy(OldBlocks, OldBlocks + e, block_begin());
    155 
    156   Use::zap(OldOps, OldOps + e, true);
    157 }
    158 
    159 /// hasConstantValue - If the specified PHI node always merges together the same
    160 /// value, return the value, otherwise return null.
    161 Value *PHINode::hasConstantValue() const {
    162   // Exploit the fact that phi nodes always have at least one entry.
    163   Value *ConstantValue = getIncomingValue(0);
    164   for (unsigned i = 1, e = getNumIncomingValues(); i != e; ++i)
    165     if (getIncomingValue(i) != ConstantValue && getIncomingValue(i) != this) {
    166       if (ConstantValue != this)
    167         return nullptr; // Incoming values not all the same.
    168        // The case where the first value is this PHI.
    169       ConstantValue = getIncomingValue(i);
    170     }
    171   if (ConstantValue == this)
    172     return UndefValue::get(getType());
    173   return ConstantValue;
    174 }
    175 
    176 //===----------------------------------------------------------------------===//
    177 //                       LandingPadInst Implementation
    178 //===----------------------------------------------------------------------===//
    179 
    180 LandingPadInst::LandingPadInst(Type *RetTy, Value *PersonalityFn,
    181                                unsigned NumReservedValues, const Twine &NameStr,
    182                                Instruction *InsertBefore)
    183   : Instruction(RetTy, Instruction::LandingPad, nullptr, 0, InsertBefore) {
    184   init(PersonalityFn, 1 + NumReservedValues, NameStr);
    185 }
    186 
    187 LandingPadInst::LandingPadInst(Type *RetTy, Value *PersonalityFn,
    188                                unsigned NumReservedValues, const Twine &NameStr,
    189                                BasicBlock *InsertAtEnd)
    190   : Instruction(RetTy, Instruction::LandingPad, nullptr, 0, InsertAtEnd) {
    191   init(PersonalityFn, 1 + NumReservedValues, NameStr);
    192 }
    193 
    194 LandingPadInst::LandingPadInst(const LandingPadInst &LP)
    195   : Instruction(LP.getType(), Instruction::LandingPad,
    196                 allocHungoffUses(LP.getNumOperands()), LP.getNumOperands()),
    197     ReservedSpace(LP.getNumOperands()) {
    198   Use *OL = OperandList, *InOL = LP.OperandList;
    199   for (unsigned I = 0, E = ReservedSpace; I != E; ++I)
    200     OL[I] = InOL[I];
    201 
    202   setCleanup(LP.isCleanup());
    203 }
    204 
    205 LandingPadInst::~LandingPadInst() {
    206   dropHungoffUses();
    207 }
    208 
    209 LandingPadInst *LandingPadInst::Create(Type *RetTy, Value *PersonalityFn,
    210                                        unsigned NumReservedClauses,
    211                                        const Twine &NameStr,
    212                                        Instruction *InsertBefore) {
    213   return new LandingPadInst(RetTy, PersonalityFn, NumReservedClauses, NameStr,
    214                             InsertBefore);
    215 }
    216 
    217 LandingPadInst *LandingPadInst::Create(Type *RetTy, Value *PersonalityFn,
    218                                        unsigned NumReservedClauses,
    219                                        const Twine &NameStr,
    220                                        BasicBlock *InsertAtEnd) {
    221   return new LandingPadInst(RetTy, PersonalityFn, NumReservedClauses, NameStr,
    222                             InsertAtEnd);
    223 }
    224 
    225 void LandingPadInst::init(Value *PersFn, unsigned NumReservedValues,
    226                           const Twine &NameStr) {
    227   ReservedSpace = NumReservedValues;
    228   NumOperands = 1;
    229   OperandList = allocHungoffUses(ReservedSpace);
    230   OperandList[0] = PersFn;
    231   setName(NameStr);
    232   setCleanup(false);
    233 }
    234 
    235 /// growOperands - grow operands - This grows the operand list in response to a
    236 /// push_back style of operation. This grows the number of ops by 2 times.
    237 void LandingPadInst::growOperands(unsigned Size) {
    238   unsigned e = getNumOperands();
    239   if (ReservedSpace >= e + Size) return;
    240   ReservedSpace = (e + Size / 2) * 2;
    241 
    242   Use *NewOps = allocHungoffUses(ReservedSpace);
    243   Use *OldOps = OperandList;
    244   for (unsigned i = 0; i != e; ++i)
    245       NewOps[i] = OldOps[i];
    246 
    247   OperandList = NewOps;
    248   Use::zap(OldOps, OldOps + e, true);
    249 }
    250 
    251 void LandingPadInst::addClause(Constant *Val) {
    252   unsigned OpNo = getNumOperands();
    253   growOperands(1);
    254   assert(OpNo < ReservedSpace && "Growing didn't work!");
    255   ++NumOperands;
    256   OperandList[OpNo] = Val;
    257 }
    258 
    259 //===----------------------------------------------------------------------===//
    260 //                        CallInst Implementation
    261 //===----------------------------------------------------------------------===//
    262 
    263 CallInst::~CallInst() {
    264 }
    265 
    266 void CallInst::init(Value *Func, ArrayRef<Value *> Args, const Twine &NameStr) {
    267   assert(NumOperands == Args.size() + 1 && "NumOperands not set up?");
    268   Op<-1>() = Func;
    269 
    270 #ifndef NDEBUG
    271   FunctionType *FTy =
    272     cast<FunctionType>(cast<PointerType>(Func->getType())->getElementType());
    273 
    274   assert((Args.size() == FTy->getNumParams() ||
    275           (FTy->isVarArg() && Args.size() > FTy->getNumParams())) &&
    276          "Calling a function with bad signature!");
    277 
    278   for (unsigned i = 0; i != Args.size(); ++i)
    279     assert((i >= FTy->getNumParams() ||
    280             FTy->getParamType(i) == Args[i]->getType()) &&
    281            "Calling a function with a bad signature!");
    282 #endif
    283 
    284   std::copy(Args.begin(), Args.end(), op_begin());
    285   setName(NameStr);
    286 }
    287 
    288 void CallInst::init(Value *Func, const Twine &NameStr) {
    289   assert(NumOperands == 1 && "NumOperands not set up?");
    290   Op<-1>() = Func;
    291 
    292 #ifndef NDEBUG
    293   FunctionType *FTy =
    294     cast<FunctionType>(cast<PointerType>(Func->getType())->getElementType());
    295 
    296   assert(FTy->getNumParams() == 0 && "Calling a function with bad signature");
    297 #endif
    298 
    299   setName(NameStr);
    300 }
    301 
    302 CallInst::CallInst(Value *Func, const Twine &Name,
    303                    Instruction *InsertBefore)
    304   : Instruction(cast<FunctionType>(cast<PointerType>(Func->getType())
    305                                    ->getElementType())->getReturnType(),
    306                 Instruction::Call,
    307                 OperandTraits<CallInst>::op_end(this) - 1,
    308                 1, InsertBefore) {
    309   init(Func, Name);
    310 }
    311 
    312 CallInst::CallInst(Value *Func, const Twine &Name,
    313                    BasicBlock *InsertAtEnd)
    314   : Instruction(cast<FunctionType>(cast<PointerType>(Func->getType())
    315                                    ->getElementType())->getReturnType(),
    316                 Instruction::Call,
    317                 OperandTraits<CallInst>::op_end(this) - 1,
    318                 1, InsertAtEnd) {
    319   init(Func, Name);
    320 }
    321 
    322 CallInst::CallInst(const CallInst &CI)
    323   : Instruction(CI.getType(), Instruction::Call,
    324                 OperandTraits<CallInst>::op_end(this) - CI.getNumOperands(),
    325                 CI.getNumOperands()) {
    326   setAttributes(CI.getAttributes());
    327   setTailCallKind(CI.getTailCallKind());
    328   setCallingConv(CI.getCallingConv());
    329 
    330   std::copy(CI.op_begin(), CI.op_end(), op_begin());
    331   SubclassOptionalData = CI.SubclassOptionalData;
    332 }
    333 
    334 void CallInst::addAttribute(unsigned i, Attribute::AttrKind attr) {
    335   AttributeSet PAL = getAttributes();
    336   PAL = PAL.addAttribute(getContext(), i, attr);
    337   setAttributes(PAL);
    338 }
    339 
    340 void CallInst::removeAttribute(unsigned i, Attribute attr) {
    341   AttributeSet PAL = getAttributes();
    342   AttrBuilder B(attr);
    343   LLVMContext &Context = getContext();
    344   PAL = PAL.removeAttributes(Context, i,
    345                              AttributeSet::get(Context, i, B));
    346   setAttributes(PAL);
    347 }
    348 
    349 void CallInst::addDereferenceableAttr(unsigned i, uint64_t Bytes) {
    350   AttributeSet PAL = getAttributes();
    351   PAL = PAL.addDereferenceableAttr(getContext(), i, Bytes);
    352   setAttributes(PAL);
    353 }
    354 
    355 void CallInst::addDereferenceableOrNullAttr(unsigned i, uint64_t Bytes) {
    356   AttributeSet PAL = getAttributes();
    357   PAL = PAL.addDereferenceableOrNullAttr(getContext(), i, Bytes);
    358   setAttributes(PAL);
    359 }
    360 
    361 bool CallInst::hasFnAttrImpl(Attribute::AttrKind A) const {
    362   if (AttributeList.hasAttribute(AttributeSet::FunctionIndex, A))
    363     return true;
    364   if (const Function *F = getCalledFunction())
    365     return F->getAttributes().hasAttribute(AttributeSet::FunctionIndex, A);
    366   return false;
    367 }
    368 
    369 bool CallInst::paramHasAttr(unsigned i, Attribute::AttrKind A) const {
    370   if (AttributeList.hasAttribute(i, A))
    371     return true;
    372   if (const Function *F = getCalledFunction())
    373     return F->getAttributes().hasAttribute(i, A);
    374   return false;
    375 }
    376 
    377 /// IsConstantOne - Return true only if val is constant int 1
    378 static bool IsConstantOne(Value *val) {
    379   assert(val && "IsConstantOne does not work with nullptr val");
    380   const ConstantInt *CVal = dyn_cast<ConstantInt>(val);
    381   return CVal && CVal->isOne();
    382 }
    383 
    384 static Instruction *createMalloc(Instruction *InsertBefore,
    385                                  BasicBlock *InsertAtEnd, Type *IntPtrTy,
    386                                  Type *AllocTy, Value *AllocSize,
    387                                  Value *ArraySize, Function *MallocF,
    388                                  const Twine &Name) {
    389   assert(((!InsertBefore && InsertAtEnd) || (InsertBefore && !InsertAtEnd)) &&
    390          "createMalloc needs either InsertBefore or InsertAtEnd");
    391 
    392   // malloc(type) becomes:
    393   //       bitcast (i8* malloc(typeSize)) to type*
    394   // malloc(type, arraySize) becomes:
    395   //       bitcast (i8 *malloc(typeSize*arraySize)) to type*
    396   if (!ArraySize)
    397     ArraySize = ConstantInt::get(IntPtrTy, 1);
    398   else if (ArraySize->getType() != IntPtrTy) {
    399     if (InsertBefore)
    400       ArraySize = CastInst::CreateIntegerCast(ArraySize, IntPtrTy, false,
    401                                               "", InsertBefore);
    402     else
    403       ArraySize = CastInst::CreateIntegerCast(ArraySize, IntPtrTy, false,
    404                                               "", InsertAtEnd);
    405   }
    406 
    407   if (!IsConstantOne(ArraySize)) {
    408     if (IsConstantOne(AllocSize)) {
    409       AllocSize = ArraySize;         // Operand * 1 = Operand
    410     } else if (Constant *CO = dyn_cast<Constant>(ArraySize)) {
    411       Constant *Scale = ConstantExpr::getIntegerCast(CO, IntPtrTy,
    412                                                      false /*ZExt*/);
    413       // Malloc arg is constant product of type size and array size
    414       AllocSize = ConstantExpr::getMul(Scale, cast<Constant>(AllocSize));
    415     } else {
    416       // Multiply type size by the array size...
    417       if (InsertBefore)
    418         AllocSize = BinaryOperator::CreateMul(ArraySize, AllocSize,
    419                                               "mallocsize", InsertBefore);
    420       else
    421         AllocSize = BinaryOperator::CreateMul(ArraySize, AllocSize,
    422                                               "mallocsize", InsertAtEnd);
    423     }
    424   }
    425 
    426   assert(AllocSize->getType() == IntPtrTy && "malloc arg is wrong size");
    427   // Create the call to Malloc.
    428   BasicBlock* BB = InsertBefore ? InsertBefore->getParent() : InsertAtEnd;
    429   Module* M = BB->getParent()->getParent();
    430   Type *BPTy = Type::getInt8PtrTy(BB->getContext());
    431   Value *MallocFunc = MallocF;
    432   if (!MallocFunc)
    433     // prototype malloc as "void *malloc(size_t)"
    434     MallocFunc = M->getOrInsertFunction("malloc", BPTy, IntPtrTy, nullptr);
    435   PointerType *AllocPtrType = PointerType::getUnqual(AllocTy);
    436   CallInst *MCall = nullptr;
    437   Instruction *Result = nullptr;
    438   if (InsertBefore) {
    439     MCall = CallInst::Create(MallocFunc, AllocSize, "malloccall", InsertBefore);
    440     Result = MCall;
    441     if (Result->getType() != AllocPtrType)
    442       // Create a cast instruction to convert to the right type...
    443       Result = new BitCastInst(MCall, AllocPtrType, Name, InsertBefore);
    444   } else {
    445     MCall = CallInst::Create(MallocFunc, AllocSize, "malloccall");
    446     Result = MCall;
    447     if (Result->getType() != AllocPtrType) {
    448       InsertAtEnd->getInstList().push_back(MCall);
    449       // Create a cast instruction to convert to the right type...
    450       Result = new BitCastInst(MCall, AllocPtrType, Name);
    451     }
    452   }
    453   MCall->setTailCall();
    454   if (Function *F = dyn_cast<Function>(MallocFunc)) {
    455     MCall->setCallingConv(F->getCallingConv());
    456     if (!F->doesNotAlias(0)) F->setDoesNotAlias(0);
    457   }
    458   assert(!MCall->getType()->isVoidTy() && "Malloc has void return type");
    459 
    460   return Result;
    461 }
    462 
    463 /// CreateMalloc - Generate the IR for a call to malloc:
    464 /// 1. Compute the malloc call's argument as the specified type's size,
    465 ///    possibly multiplied by the array size if the array size is not
    466 ///    constant 1.
    467 /// 2. Call malloc with that argument.
    468 /// 3. Bitcast the result of the malloc call to the specified type.
    469 Instruction *CallInst::CreateMalloc(Instruction *InsertBefore,
    470                                     Type *IntPtrTy, Type *AllocTy,
    471                                     Value *AllocSize, Value *ArraySize,
    472                                     Function * MallocF,
    473                                     const Twine &Name) {
    474   return createMalloc(InsertBefore, nullptr, IntPtrTy, AllocTy, AllocSize,
    475                       ArraySize, MallocF, Name);
    476 }
    477 
    478 /// CreateMalloc - Generate the IR for a call to malloc:
    479 /// 1. Compute the malloc call's argument as the specified type's size,
    480 ///    possibly multiplied by the array size if the array size is not
    481 ///    constant 1.
    482 /// 2. Call malloc with that argument.
    483 /// 3. Bitcast the result of the malloc call to the specified type.
    484 /// Note: This function does not add the bitcast to the basic block, that is the
    485 /// responsibility of the caller.
    486 Instruction *CallInst::CreateMalloc(BasicBlock *InsertAtEnd,
    487                                     Type *IntPtrTy, Type *AllocTy,
    488                                     Value *AllocSize, Value *ArraySize,
    489                                     Function *MallocF, const Twine &Name) {
    490   return createMalloc(nullptr, InsertAtEnd, IntPtrTy, AllocTy, AllocSize,
    491                       ArraySize, MallocF, Name);
    492 }
    493 
    494 static Instruction* createFree(Value* Source, Instruction *InsertBefore,
    495                                BasicBlock *InsertAtEnd) {
    496   assert(((!InsertBefore && InsertAtEnd) || (InsertBefore && !InsertAtEnd)) &&
    497          "createFree needs either InsertBefore or InsertAtEnd");
    498   assert(Source->getType()->isPointerTy() &&
    499          "Can not free something of nonpointer type!");
    500 
    501   BasicBlock* BB = InsertBefore ? InsertBefore->getParent() : InsertAtEnd;
    502   Module* M = BB->getParent()->getParent();
    503 
    504   Type *VoidTy = Type::getVoidTy(M->getContext());
    505   Type *IntPtrTy = Type::getInt8PtrTy(M->getContext());
    506   // prototype free as "void free(void*)"
    507   Value *FreeFunc = M->getOrInsertFunction("free", VoidTy, IntPtrTy, nullptr);
    508   CallInst* Result = nullptr;
    509   Value *PtrCast = Source;
    510   if (InsertBefore) {
    511     if (Source->getType() != IntPtrTy)
    512       PtrCast = new BitCastInst(Source, IntPtrTy, "", InsertBefore);
    513     Result = CallInst::Create(FreeFunc, PtrCast, "", InsertBefore);
    514   } else {
    515     if (Source->getType() != IntPtrTy)
    516       PtrCast = new BitCastInst(Source, IntPtrTy, "", InsertAtEnd);
    517     Result = CallInst::Create(FreeFunc, PtrCast, "");
    518   }
    519   Result->setTailCall();
    520   if (Function *F = dyn_cast<Function>(FreeFunc))
    521     Result->setCallingConv(F->getCallingConv());
    522 
    523   return Result;
    524 }
    525 
    526 /// CreateFree - Generate the IR for a call to the builtin free function.
    527 Instruction * CallInst::CreateFree(Value* Source, Instruction *InsertBefore) {
    528   return createFree(Source, InsertBefore, nullptr);
    529 }
    530 
    531 /// CreateFree - Generate the IR for a call to the builtin free function.
    532 /// Note: This function does not add the call to the basic block, that is the
    533 /// responsibility of the caller.
    534 Instruction* CallInst::CreateFree(Value* Source, BasicBlock *InsertAtEnd) {
    535   Instruction* FreeCall = createFree(Source, nullptr, InsertAtEnd);
    536   assert(FreeCall && "CreateFree did not create a CallInst");
    537   return FreeCall;
    538 }
    539 
    540 //===----------------------------------------------------------------------===//
    541 //                        InvokeInst Implementation
    542 //===----------------------------------------------------------------------===//
    543 
    544 void InvokeInst::init(Value *Fn, BasicBlock *IfNormal, BasicBlock *IfException,
    545                       ArrayRef<Value *> Args, const Twine &NameStr) {
    546   assert(NumOperands == 3 + Args.size() && "NumOperands not set up?");
    547   Op<-3>() = Fn;
    548   Op<-2>() = IfNormal;
    549   Op<-1>() = IfException;
    550 
    551 #ifndef NDEBUG
    552   FunctionType *FTy =
    553     cast<FunctionType>(cast<PointerType>(Fn->getType())->getElementType());
    554 
    555   assert(((Args.size() == FTy->getNumParams()) ||
    556           (FTy->isVarArg() && Args.size() > FTy->getNumParams())) &&
    557          "Invoking a function with bad signature");
    558 
    559   for (unsigned i = 0, e = Args.size(); i != e; i++)
    560     assert((i >= FTy->getNumParams() ||
    561             FTy->getParamType(i) == Args[i]->getType()) &&
    562            "Invoking a function with a bad signature!");
    563 #endif
    564 
    565   std::copy(Args.begin(), Args.end(), op_begin());
    566   setName(NameStr);
    567 }
    568 
    569 InvokeInst::InvokeInst(const InvokeInst &II)
    570   : TerminatorInst(II.getType(), Instruction::Invoke,
    571                    OperandTraits<InvokeInst>::op_end(this)
    572                    - II.getNumOperands(),
    573                    II.getNumOperands()) {
    574   setAttributes(II.getAttributes());
    575   setCallingConv(II.getCallingConv());
    576   std::copy(II.op_begin(), II.op_end(), op_begin());
    577   SubclassOptionalData = II.SubclassOptionalData;
    578 }
    579 
    580 BasicBlock *InvokeInst::getSuccessorV(unsigned idx) const {
    581   return getSuccessor(idx);
    582 }
    583 unsigned InvokeInst::getNumSuccessorsV() const {
    584   return getNumSuccessors();
    585 }
    586 void InvokeInst::setSuccessorV(unsigned idx, BasicBlock *B) {
    587   return setSuccessor(idx, B);
    588 }
    589 
    590 bool InvokeInst::hasFnAttrImpl(Attribute::AttrKind A) const {
    591   if (AttributeList.hasAttribute(AttributeSet::FunctionIndex, A))
    592     return true;
    593   if (const Function *F = getCalledFunction())
    594     return F->getAttributes().hasAttribute(AttributeSet::FunctionIndex, A);
    595   return false;
    596 }
    597 
    598 bool InvokeInst::paramHasAttr(unsigned i, Attribute::AttrKind A) const {
    599   if (AttributeList.hasAttribute(i, A))
    600     return true;
    601   if (const Function *F = getCalledFunction())
    602     return F->getAttributes().hasAttribute(i, A);
    603   return false;
    604 }
    605 
    606 void InvokeInst::addAttribute(unsigned i, Attribute::AttrKind attr) {
    607   AttributeSet PAL = getAttributes();
    608   PAL = PAL.addAttribute(getContext(), i, attr);
    609   setAttributes(PAL);
    610 }
    611 
    612 void InvokeInst::removeAttribute(unsigned i, Attribute attr) {
    613   AttributeSet PAL = getAttributes();
    614   AttrBuilder B(attr);
    615   PAL = PAL.removeAttributes(getContext(), i,
    616                              AttributeSet::get(getContext(), i, B));
    617   setAttributes(PAL);
    618 }
    619 
    620 void InvokeInst::addDereferenceableAttr(unsigned i, uint64_t Bytes) {
    621   AttributeSet PAL = getAttributes();
    622   PAL = PAL.addDereferenceableAttr(getContext(), i, Bytes);
    623   setAttributes(PAL);
    624 }
    625 
    626 void InvokeInst::addDereferenceableOrNullAttr(unsigned i, uint64_t Bytes) {
    627   AttributeSet PAL = getAttributes();
    628   PAL = PAL.addDereferenceableOrNullAttr(getContext(), i, Bytes);
    629   setAttributes(PAL);
    630 }
    631 
    632 LandingPadInst *InvokeInst::getLandingPadInst() const {
    633   return cast<LandingPadInst>(getUnwindDest()->getFirstNonPHI());
    634 }
    635 
    636 //===----------------------------------------------------------------------===//
    637 //                        ReturnInst Implementation
    638 //===----------------------------------------------------------------------===//
    639 
    640 ReturnInst::ReturnInst(const ReturnInst &RI)
    641   : TerminatorInst(Type::getVoidTy(RI.getContext()), Instruction::Ret,
    642                    OperandTraits<ReturnInst>::op_end(this) -
    643                      RI.getNumOperands(),
    644                    RI.getNumOperands()) {
    645   if (RI.getNumOperands())
    646     Op<0>() = RI.Op<0>();
    647   SubclassOptionalData = RI.SubclassOptionalData;
    648 }
    649 
    650 ReturnInst::ReturnInst(LLVMContext &C, Value *retVal, Instruction *InsertBefore)
    651   : TerminatorInst(Type::getVoidTy(C), Instruction::Ret,
    652                    OperandTraits<ReturnInst>::op_end(this) - !!retVal, !!retVal,
    653                    InsertBefore) {
    654   if (retVal)
    655     Op<0>() = retVal;
    656 }
    657 ReturnInst::ReturnInst(LLVMContext &C, Value *retVal, BasicBlock *InsertAtEnd)
    658   : TerminatorInst(Type::getVoidTy(C), Instruction::Ret,
    659                    OperandTraits<ReturnInst>::op_end(this) - !!retVal, !!retVal,
    660                    InsertAtEnd) {
    661   if (retVal)
    662     Op<0>() = retVal;
    663 }
    664 ReturnInst::ReturnInst(LLVMContext &Context, BasicBlock *InsertAtEnd)
    665   : TerminatorInst(Type::getVoidTy(Context), Instruction::Ret,
    666                    OperandTraits<ReturnInst>::op_end(this), 0, InsertAtEnd) {
    667 }
    668 
    669 unsigned ReturnInst::getNumSuccessorsV() const {
    670   return getNumSuccessors();
    671 }
    672 
    673 /// Out-of-line ReturnInst method, put here so the C++ compiler can choose to
    674 /// emit the vtable for the class in this translation unit.
    675 void ReturnInst::setSuccessorV(unsigned idx, BasicBlock *NewSucc) {
    676   llvm_unreachable("ReturnInst has no successors!");
    677 }
    678 
    679 BasicBlock *ReturnInst::getSuccessorV(unsigned idx) const {
    680   llvm_unreachable("ReturnInst has no successors!");
    681 }
    682 
    683 ReturnInst::~ReturnInst() {
    684 }
    685 
    686 //===----------------------------------------------------------------------===//
    687 //                        ResumeInst Implementation
    688 //===----------------------------------------------------------------------===//
    689 
    690 ResumeInst::ResumeInst(const ResumeInst &RI)
    691   : TerminatorInst(Type::getVoidTy(RI.getContext()), Instruction::Resume,
    692                    OperandTraits<ResumeInst>::op_begin(this), 1) {
    693   Op<0>() = RI.Op<0>();
    694 }
    695 
    696 ResumeInst::ResumeInst(Value *Exn, Instruction *InsertBefore)
    697   : TerminatorInst(Type::getVoidTy(Exn->getContext()), Instruction::Resume,
    698                    OperandTraits<ResumeInst>::op_begin(this), 1, InsertBefore) {
    699   Op<0>() = Exn;
    700 }
    701 
    702 ResumeInst::ResumeInst(Value *Exn, BasicBlock *InsertAtEnd)
    703   : TerminatorInst(Type::getVoidTy(Exn->getContext()), Instruction::Resume,
    704                    OperandTraits<ResumeInst>::op_begin(this), 1, InsertAtEnd) {
    705   Op<0>() = Exn;
    706 }
    707 
    708 unsigned ResumeInst::getNumSuccessorsV() const {
    709   return getNumSuccessors();
    710 }
    711 
    712 void ResumeInst::setSuccessorV(unsigned idx, BasicBlock *NewSucc) {
    713   llvm_unreachable("ResumeInst has no successors!");
    714 }
    715 
    716 BasicBlock *ResumeInst::getSuccessorV(unsigned idx) const {
    717   llvm_unreachable("ResumeInst has no successors!");
    718 }
    719 
    720 //===----------------------------------------------------------------------===//
    721 //                      UnreachableInst Implementation
    722 //===----------------------------------------------------------------------===//
    723 
    724 UnreachableInst::UnreachableInst(LLVMContext &Context,
    725                                  Instruction *InsertBefore)
    726   : TerminatorInst(Type::getVoidTy(Context), Instruction::Unreachable,
    727                    nullptr, 0, InsertBefore) {
    728 }
    729 UnreachableInst::UnreachableInst(LLVMContext &Context, BasicBlock *InsertAtEnd)
    730   : TerminatorInst(Type::getVoidTy(Context), Instruction::Unreachable,
    731                    nullptr, 0, InsertAtEnd) {
    732 }
    733 
    734 unsigned UnreachableInst::getNumSuccessorsV() const {
    735   return getNumSuccessors();
    736 }
    737 
    738 void UnreachableInst::setSuccessorV(unsigned idx, BasicBlock *NewSucc) {
    739   llvm_unreachable("UnreachableInst has no successors!");
    740 }
    741 
    742 BasicBlock *UnreachableInst::getSuccessorV(unsigned idx) const {
    743   llvm_unreachable("UnreachableInst has no successors!");
    744 }
    745 
    746 //===----------------------------------------------------------------------===//
    747 //                        BranchInst Implementation
    748 //===----------------------------------------------------------------------===//
    749 
    750 void BranchInst::AssertOK() {
    751   if (isConditional())
    752     assert(getCondition()->getType()->isIntegerTy(1) &&
    753            "May only branch on boolean predicates!");
    754 }
    755 
    756 BranchInst::BranchInst(BasicBlock *IfTrue, Instruction *InsertBefore)
    757   : TerminatorInst(Type::getVoidTy(IfTrue->getContext()), Instruction::Br,
    758                    OperandTraits<BranchInst>::op_end(this) - 1,
    759                    1, InsertBefore) {
    760   assert(IfTrue && "Branch destination may not be null!");
    761   Op<-1>() = IfTrue;
    762 }
    763 BranchInst::BranchInst(BasicBlock *IfTrue, BasicBlock *IfFalse, Value *Cond,
    764                        Instruction *InsertBefore)
    765   : TerminatorInst(Type::getVoidTy(IfTrue->getContext()), Instruction::Br,
    766                    OperandTraits<BranchInst>::op_end(this) - 3,
    767                    3, InsertBefore) {
    768   Op<-1>() = IfTrue;
    769   Op<-2>() = IfFalse;
    770   Op<-3>() = Cond;
    771 #ifndef NDEBUG
    772   AssertOK();
    773 #endif
    774 }
    775 
    776 BranchInst::BranchInst(BasicBlock *IfTrue, BasicBlock *InsertAtEnd)
    777   : TerminatorInst(Type::getVoidTy(IfTrue->getContext()), Instruction::Br,
    778                    OperandTraits<BranchInst>::op_end(this) - 1,
    779                    1, InsertAtEnd) {
    780   assert(IfTrue && "Branch destination may not be null!");
    781   Op<-1>() = IfTrue;
    782 }
    783 
    784 BranchInst::BranchInst(BasicBlock *IfTrue, BasicBlock *IfFalse, Value *Cond,
    785            BasicBlock *InsertAtEnd)
    786   : TerminatorInst(Type::getVoidTy(IfTrue->getContext()), Instruction::Br,
    787                    OperandTraits<BranchInst>::op_end(this) - 3,
    788                    3, InsertAtEnd) {
    789   Op<-1>() = IfTrue;
    790   Op<-2>() = IfFalse;
    791   Op<-3>() = Cond;
    792 #ifndef NDEBUG
    793   AssertOK();
    794 #endif
    795 }
    796 
    797 
    798 BranchInst::BranchInst(const BranchInst &BI) :
    799   TerminatorInst(Type::getVoidTy(BI.getContext()), Instruction::Br,
    800                  OperandTraits<BranchInst>::op_end(this) - BI.getNumOperands(),
    801                  BI.getNumOperands()) {
    802   Op<-1>() = BI.Op<-1>();
    803   if (BI.getNumOperands() != 1) {
    804     assert(BI.getNumOperands() == 3 && "BR can have 1 or 3 operands!");
    805     Op<-3>() = BI.Op<-3>();
    806     Op<-2>() = BI.Op<-2>();
    807   }
    808   SubclassOptionalData = BI.SubclassOptionalData;
    809 }
    810 
    811 void BranchInst::swapSuccessors() {
    812   assert(isConditional() &&
    813          "Cannot swap successors of an unconditional branch");
    814   Op<-1>().swap(Op<-2>());
    815 
    816   // Update profile metadata if present and it matches our structural
    817   // expectations.
    818   MDNode *ProfileData = getMetadata(LLVMContext::MD_prof);
    819   if (!ProfileData || ProfileData->getNumOperands() != 3)
    820     return;
    821 
    822   // The first operand is the name. Fetch them backwards and build a new one.
    823   Metadata *Ops[] = {ProfileData->getOperand(0), ProfileData->getOperand(2),
    824                      ProfileData->getOperand(1)};
    825   setMetadata(LLVMContext::MD_prof,
    826               MDNode::get(ProfileData->getContext(), Ops));
    827 }
    828 
    829 BasicBlock *BranchInst::getSuccessorV(unsigned idx) const {
    830   return getSuccessor(idx);
    831 }
    832 unsigned BranchInst::getNumSuccessorsV() const {
    833   return getNumSuccessors();
    834 }
    835 void BranchInst::setSuccessorV(unsigned idx, BasicBlock *B) {
    836   setSuccessor(idx, B);
    837 }
    838 
    839 
    840 //===----------------------------------------------------------------------===//
    841 //                        AllocaInst Implementation
    842 //===----------------------------------------------------------------------===//
    843 
    844 static Value *getAISize(LLVMContext &Context, Value *Amt) {
    845   if (!Amt)
    846     Amt = ConstantInt::get(Type::getInt32Ty(Context), 1);
    847   else {
    848     assert(!isa<BasicBlock>(Amt) &&
    849            "Passed basic block into allocation size parameter! Use other ctor");
    850     assert(Amt->getType()->isIntegerTy() &&
    851            "Allocation array size is not an integer!");
    852   }
    853   return Amt;
    854 }
    855 
    856 AllocaInst::AllocaInst(Type *Ty, const Twine &Name, Instruction *InsertBefore)
    857     : AllocaInst(Ty, /*ArraySize=*/nullptr, Name, InsertBefore) {}
    858 
    859 AllocaInst::AllocaInst(Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd)
    860     : AllocaInst(Ty, /*ArraySize=*/nullptr, Name, InsertAtEnd) {}
    861 
    862 AllocaInst::AllocaInst(Type *Ty, Value *ArraySize, const Twine &Name,
    863                        Instruction *InsertBefore)
    864     : AllocaInst(Ty, ArraySize, /*Align=*/0, Name, InsertBefore) {}
    865 
    866 AllocaInst::AllocaInst(Type *Ty, Value *ArraySize, const Twine &Name,
    867                        BasicBlock *InsertAtEnd)
    868     : AllocaInst(Ty, ArraySize, /*Align=*/0, Name, InsertAtEnd) {}
    869 
    870 AllocaInst::AllocaInst(Type *Ty, Value *ArraySize, unsigned Align,
    871                        const Twine &Name, Instruction *InsertBefore)
    872   : UnaryInstruction(PointerType::getUnqual(Ty), Alloca,
    873                      getAISize(Ty->getContext(), ArraySize), InsertBefore) {
    874   setAlignment(Align);
    875   assert(!Ty->isVoidTy() && "Cannot allocate void!");
    876   setName(Name);
    877 }
    878 
    879 AllocaInst::AllocaInst(Type *Ty, Value *ArraySize, unsigned Align,
    880                        const Twine &Name, BasicBlock *InsertAtEnd)
    881   : UnaryInstruction(PointerType::getUnqual(Ty), Alloca,
    882                      getAISize(Ty->getContext(), ArraySize), InsertAtEnd) {
    883   setAlignment(Align);
    884   assert(!Ty->isVoidTy() && "Cannot allocate void!");
    885   setName(Name);
    886 }
    887 
    888 // Out of line virtual method, so the vtable, etc has a home.
    889 AllocaInst::~AllocaInst() {
    890 }
    891 
    892 void AllocaInst::setAlignment(unsigned Align) {
    893   assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
    894   assert(Align <= MaximumAlignment &&
    895          "Alignment is greater than MaximumAlignment!");
    896   setInstructionSubclassData((getSubclassDataFromInstruction() & ~31) |
    897                              (Log2_32(Align) + 1));
    898   assert(getAlignment() == Align && "Alignment representation error!");
    899 }
    900 
    901 bool AllocaInst::isArrayAllocation() const {
    902   if (ConstantInt *CI = dyn_cast<ConstantInt>(getOperand(0)))
    903     return !CI->isOne();
    904   return true;
    905 }
    906 
    907 Type *AllocaInst::getAllocatedType() const {
    908   return getType()->getElementType();
    909 }
    910 
    911 /// isStaticAlloca - Return true if this alloca is in the entry block of the
    912 /// function and is a constant size.  If so, the code generator will fold it
    913 /// into the prolog/epilog code, so it is basically free.
    914 bool AllocaInst::isStaticAlloca() const {
    915   // Must be constant size.
    916   if (!isa<ConstantInt>(getArraySize())) return false;
    917 
    918   // Must be in the entry block.
    919   const BasicBlock *Parent = getParent();
    920   return Parent == &Parent->getParent()->front() && !isUsedWithInAlloca();
    921 }
    922 
    923 //===----------------------------------------------------------------------===//
    924 //                           LoadInst Implementation
    925 //===----------------------------------------------------------------------===//
    926 
    927 void LoadInst::AssertOK() {
    928   assert(getOperand(0)->getType()->isPointerTy() &&
    929          "Ptr must have pointer type.");
    930   assert(!(isAtomic() && getAlignment() == 0) &&
    931          "Alignment required for atomic load");
    932 }
    933 
    934 LoadInst::LoadInst(Value *Ptr, const Twine &Name, Instruction *InsertBef)
    935     : LoadInst(Ptr, Name, /*isVolatile=*/false, InsertBef) {}
    936 
    937 LoadInst::LoadInst(Value *Ptr, const Twine &Name, BasicBlock *InsertAE)
    938     : LoadInst(Ptr, Name, /*isVolatile=*/false, InsertAE) {}
    939 
    940 LoadInst::LoadInst(Value *Ptr, const Twine &Name, bool isVolatile,
    941                    Instruction *InsertBef)
    942     : LoadInst(Ptr, Name, isVolatile, /*Align=*/0, InsertBef) {}
    943 
    944 LoadInst::LoadInst(Value *Ptr, const Twine &Name, bool isVolatile,
    945                    BasicBlock *InsertAE)
    946     : LoadInst(Ptr, Name, isVolatile, /*Align=*/0, InsertAE) {}
    947 
    948 LoadInst::LoadInst(Value *Ptr, const Twine &Name, bool isVolatile,
    949                    unsigned Align, Instruction *InsertBef)
    950     : LoadInst(Ptr, Name, isVolatile, Align, NotAtomic, CrossThread,
    951                InsertBef) {}
    952 
    953 LoadInst::LoadInst(Value *Ptr, const Twine &Name, bool isVolatile,
    954                    unsigned Align, BasicBlock *InsertAE)
    955     : LoadInst(Ptr, Name, isVolatile, Align, NotAtomic, CrossThread, InsertAE) {
    956 }
    957 
    958 LoadInst::LoadInst(Type *Ty, Value *Ptr, const Twine &Name, bool isVolatile,
    959                    unsigned Align, AtomicOrdering Order,
    960                    SynchronizationScope SynchScope, Instruction *InsertBef)
    961     : UnaryInstruction(Ty, Load, Ptr, InsertBef) {
    962   setVolatile(isVolatile);
    963   setAlignment(Align);
    964   setAtomic(Order, SynchScope);
    965   AssertOK();
    966   setName(Name);
    967 }
    968 
    969 LoadInst::LoadInst(Value *Ptr, const Twine &Name, bool isVolatile,
    970                    unsigned Align, AtomicOrdering Order,
    971                    SynchronizationScope SynchScope,
    972                    BasicBlock *InsertAE)
    973   : UnaryInstruction(cast<PointerType>(Ptr->getType())->getElementType(),
    974                      Load, Ptr, InsertAE) {
    975   setVolatile(isVolatile);
    976   setAlignment(Align);
    977   setAtomic(Order, SynchScope);
    978   AssertOK();
    979   setName(Name);
    980 }
    981 
    982 LoadInst::LoadInst(Value *Ptr, const char *Name, Instruction *InsertBef)
    983   : UnaryInstruction(cast<PointerType>(Ptr->getType())->getElementType(),
    984                      Load, Ptr, InsertBef) {
    985   setVolatile(false);
    986   setAlignment(0);
    987   setAtomic(NotAtomic);
    988   AssertOK();
    989   if (Name && Name[0]) setName(Name);
    990 }
    991 
    992 LoadInst::LoadInst(Value *Ptr, const char *Name, BasicBlock *InsertAE)
    993   : UnaryInstruction(cast<PointerType>(Ptr->getType())->getElementType(),
    994                      Load, Ptr, InsertAE) {
    995   setVolatile(false);
    996   setAlignment(0);
    997   setAtomic(NotAtomic);
    998   AssertOK();
    999   if (Name && Name[0]) setName(Name);
   1000 }
   1001 
   1002 LoadInst::LoadInst(Value *Ptr, const char *Name, bool isVolatile,
   1003                    Instruction *InsertBef)
   1004 : UnaryInstruction(cast<PointerType>(Ptr->getType())->getElementType(),
   1005                    Load, Ptr, InsertBef) {
   1006   setVolatile(isVolatile);
   1007   setAlignment(0);
   1008   setAtomic(NotAtomic);
   1009   AssertOK();
   1010   if (Name && Name[0]) setName(Name);
   1011 }
   1012 
   1013 LoadInst::LoadInst(Value *Ptr, const char *Name, bool isVolatile,
   1014                    BasicBlock *InsertAE)
   1015   : UnaryInstruction(cast<PointerType>(Ptr->getType())->getElementType(),
   1016                      Load, Ptr, InsertAE) {
   1017   setVolatile(isVolatile);
   1018   setAlignment(0);
   1019   setAtomic(NotAtomic);
   1020   AssertOK();
   1021   if (Name && Name[0]) setName(Name);
   1022 }
   1023 
   1024 void LoadInst::setAlignment(unsigned Align) {
   1025   assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
   1026   assert(Align <= MaximumAlignment &&
   1027          "Alignment is greater than MaximumAlignment!");
   1028   setInstructionSubclassData((getSubclassDataFromInstruction() & ~(31 << 1)) |
   1029                              ((Log2_32(Align)+1)<<1));
   1030   assert(getAlignment() == Align && "Alignment representation error!");
   1031 }
   1032 
   1033 //===----------------------------------------------------------------------===//
   1034 //                           StoreInst Implementation
   1035 //===----------------------------------------------------------------------===//
   1036 
   1037 void StoreInst::AssertOK() {
   1038   assert(getOperand(0) && getOperand(1) && "Both operands must be non-null!");
   1039   assert(getOperand(1)->getType()->isPointerTy() &&
   1040          "Ptr must have pointer type!");
   1041   assert(getOperand(0)->getType() ==
   1042                  cast<PointerType>(getOperand(1)->getType())->getElementType()
   1043          && "Ptr must be a pointer to Val type!");
   1044   assert(!(isAtomic() && getAlignment() == 0) &&
   1045          "Alignment required for atomic store");
   1046 }
   1047 
   1048 StoreInst::StoreInst(Value *val, Value *addr, Instruction *InsertBefore)
   1049     : StoreInst(val, addr, /*isVolatile=*/false, InsertBefore) {}
   1050 
   1051 StoreInst::StoreInst(Value *val, Value *addr, BasicBlock *InsertAtEnd)
   1052     : StoreInst(val, addr, /*isVolatile=*/false, InsertAtEnd) {}
   1053 
   1054 StoreInst::StoreInst(Value *val, Value *addr, bool isVolatile,
   1055                      Instruction *InsertBefore)
   1056     : StoreInst(val, addr, isVolatile, /*Align=*/0, InsertBefore) {}
   1057 
   1058 StoreInst::StoreInst(Value *val, Value *addr, bool isVolatile,
   1059                      BasicBlock *InsertAtEnd)
   1060     : StoreInst(val, addr, isVolatile, /*Align=*/0, InsertAtEnd) {}
   1061 
   1062 StoreInst::StoreInst(Value *val, Value *addr, bool isVolatile, unsigned Align,
   1063                      Instruction *InsertBefore)
   1064     : StoreInst(val, addr, isVolatile, Align, NotAtomic, CrossThread,
   1065                 InsertBefore) {}
   1066 
   1067 StoreInst::StoreInst(Value *val, Value *addr, bool isVolatile, unsigned Align,
   1068                      BasicBlock *InsertAtEnd)
   1069     : StoreInst(val, addr, isVolatile, Align, NotAtomic, CrossThread,
   1070                 InsertAtEnd) {}
   1071 
   1072 StoreInst::StoreInst(Value *val, Value *addr, bool isVolatile,
   1073                      unsigned Align, AtomicOrdering Order,
   1074                      SynchronizationScope SynchScope,
   1075                      Instruction *InsertBefore)
   1076   : Instruction(Type::getVoidTy(val->getContext()), Store,
   1077                 OperandTraits<StoreInst>::op_begin(this),
   1078                 OperandTraits<StoreInst>::operands(this),
   1079                 InsertBefore) {
   1080   Op<0>() = val;
   1081   Op<1>() = addr;
   1082   setVolatile(isVolatile);
   1083   setAlignment(Align);
   1084   setAtomic(Order, SynchScope);
   1085   AssertOK();
   1086 }
   1087 
   1088 StoreInst::StoreInst(Value *val, Value *addr, bool isVolatile,
   1089                      unsigned Align, AtomicOrdering Order,
   1090                      SynchronizationScope SynchScope,
   1091                      BasicBlock *InsertAtEnd)
   1092   : Instruction(Type::getVoidTy(val->getContext()), Store,
   1093                 OperandTraits<StoreInst>::op_begin(this),
   1094                 OperandTraits<StoreInst>::operands(this),
   1095                 InsertAtEnd) {
   1096   Op<0>() = val;
   1097   Op<1>() = addr;
   1098   setVolatile(isVolatile);
   1099   setAlignment(Align);
   1100   setAtomic(Order, SynchScope);
   1101   AssertOK();
   1102 }
   1103 
   1104 void StoreInst::setAlignment(unsigned Align) {
   1105   assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
   1106   assert(Align <= MaximumAlignment &&
   1107          "Alignment is greater than MaximumAlignment!");
   1108   setInstructionSubclassData((getSubclassDataFromInstruction() & ~(31 << 1)) |
   1109                              ((Log2_32(Align)+1) << 1));
   1110   assert(getAlignment() == Align && "Alignment representation error!");
   1111 }
   1112 
   1113 //===----------------------------------------------------------------------===//
   1114 //                       AtomicCmpXchgInst Implementation
   1115 //===----------------------------------------------------------------------===//
   1116 
   1117 void AtomicCmpXchgInst::Init(Value *Ptr, Value *Cmp, Value *NewVal,
   1118                              AtomicOrdering SuccessOrdering,
   1119                              AtomicOrdering FailureOrdering,
   1120                              SynchronizationScope SynchScope) {
   1121   Op<0>() = Ptr;
   1122   Op<1>() = Cmp;
   1123   Op<2>() = NewVal;
   1124   setSuccessOrdering(SuccessOrdering);
   1125   setFailureOrdering(FailureOrdering);
   1126   setSynchScope(SynchScope);
   1127 
   1128   assert(getOperand(0) && getOperand(1) && getOperand(2) &&
   1129          "All operands must be non-null!");
   1130   assert(getOperand(0)->getType()->isPointerTy() &&
   1131          "Ptr must have pointer type!");
   1132   assert(getOperand(1)->getType() ==
   1133                  cast<PointerType>(getOperand(0)->getType())->getElementType()
   1134          && "Ptr must be a pointer to Cmp type!");
   1135   assert(getOperand(2)->getType() ==
   1136                  cast<PointerType>(getOperand(0)->getType())->getElementType()
   1137          && "Ptr must be a pointer to NewVal type!");
   1138   assert(SuccessOrdering != NotAtomic &&
   1139          "AtomicCmpXchg instructions must be atomic!");
   1140   assert(FailureOrdering != NotAtomic &&
   1141          "AtomicCmpXchg instructions must be atomic!");
   1142   assert(SuccessOrdering >= FailureOrdering &&
   1143          "AtomicCmpXchg success ordering must be at least as strong as fail");
   1144   assert(FailureOrdering != Release && FailureOrdering != AcquireRelease &&
   1145          "AtomicCmpXchg failure ordering cannot include release semantics");
   1146 }
   1147 
   1148 AtomicCmpXchgInst::AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
   1149                                      AtomicOrdering SuccessOrdering,
   1150                                      AtomicOrdering FailureOrdering,
   1151                                      SynchronizationScope SynchScope,
   1152                                      Instruction *InsertBefore)
   1153     : Instruction(
   1154           StructType::get(Cmp->getType(), Type::getInt1Ty(Cmp->getContext()),
   1155                           nullptr),
   1156           AtomicCmpXchg, OperandTraits<AtomicCmpXchgInst>::op_begin(this),
   1157           OperandTraits<AtomicCmpXchgInst>::operands(this), InsertBefore) {
   1158   Init(Ptr, Cmp, NewVal, SuccessOrdering, FailureOrdering, SynchScope);
   1159 }
   1160 
   1161 AtomicCmpXchgInst::AtomicCmpXchgInst(Value *Ptr, Value *Cmp, Value *NewVal,
   1162                                      AtomicOrdering SuccessOrdering,
   1163                                      AtomicOrdering FailureOrdering,
   1164                                      SynchronizationScope SynchScope,
   1165                                      BasicBlock *InsertAtEnd)
   1166     : Instruction(
   1167           StructType::get(Cmp->getType(), Type::getInt1Ty(Cmp->getContext()),
   1168                           nullptr),
   1169           AtomicCmpXchg, OperandTraits<AtomicCmpXchgInst>::op_begin(this),
   1170           OperandTraits<AtomicCmpXchgInst>::operands(this), InsertAtEnd) {
   1171   Init(Ptr, Cmp, NewVal, SuccessOrdering, FailureOrdering, SynchScope);
   1172 }
   1173 
   1174 //===----------------------------------------------------------------------===//
   1175 //                       AtomicRMWInst Implementation
   1176 //===----------------------------------------------------------------------===//
   1177 
   1178 void AtomicRMWInst::Init(BinOp Operation, Value *Ptr, Value *Val,
   1179                          AtomicOrdering Ordering,
   1180                          SynchronizationScope SynchScope) {
   1181   Op<0>() = Ptr;
   1182   Op<1>() = Val;
   1183   setOperation(Operation);
   1184   setOrdering(Ordering);
   1185   setSynchScope(SynchScope);
   1186 
   1187   assert(getOperand(0) && getOperand(1) &&
   1188          "All operands must be non-null!");
   1189   assert(getOperand(0)->getType()->isPointerTy() &&
   1190          "Ptr must have pointer type!");
   1191   assert(getOperand(1)->getType() ==
   1192          cast<PointerType>(getOperand(0)->getType())->getElementType()
   1193          && "Ptr must be a pointer to Val type!");
   1194   assert(Ordering != NotAtomic &&
   1195          "AtomicRMW instructions must be atomic!");
   1196 }
   1197 
   1198 AtomicRMWInst::AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
   1199                              AtomicOrdering Ordering,
   1200                              SynchronizationScope SynchScope,
   1201                              Instruction *InsertBefore)
   1202   : Instruction(Val->getType(), AtomicRMW,
   1203                 OperandTraits<AtomicRMWInst>::op_begin(this),
   1204                 OperandTraits<AtomicRMWInst>::operands(this),
   1205                 InsertBefore) {
   1206   Init(Operation, Ptr, Val, Ordering, SynchScope);
   1207 }
   1208 
   1209 AtomicRMWInst::AtomicRMWInst(BinOp Operation, Value *Ptr, Value *Val,
   1210                              AtomicOrdering Ordering,
   1211                              SynchronizationScope SynchScope,
   1212                              BasicBlock *InsertAtEnd)
   1213   : Instruction(Val->getType(), AtomicRMW,
   1214                 OperandTraits<AtomicRMWInst>::op_begin(this),
   1215                 OperandTraits<AtomicRMWInst>::operands(this),
   1216                 InsertAtEnd) {
   1217   Init(Operation, Ptr, Val, Ordering, SynchScope);
   1218 }
   1219 
   1220 //===----------------------------------------------------------------------===//
   1221 //                       FenceInst Implementation
   1222 //===----------------------------------------------------------------------===//
   1223 
   1224 FenceInst::FenceInst(LLVMContext &C, AtomicOrdering Ordering,
   1225                      SynchronizationScope SynchScope,
   1226                      Instruction *InsertBefore)
   1227   : Instruction(Type::getVoidTy(C), Fence, nullptr, 0, InsertBefore) {
   1228   setOrdering(Ordering);
   1229   setSynchScope(SynchScope);
   1230 }
   1231 
   1232 FenceInst::FenceInst(LLVMContext &C, AtomicOrdering Ordering,
   1233                      SynchronizationScope SynchScope,
   1234                      BasicBlock *InsertAtEnd)
   1235   : Instruction(Type::getVoidTy(C), Fence, nullptr, 0, InsertAtEnd) {
   1236   setOrdering(Ordering);
   1237   setSynchScope(SynchScope);
   1238 }
   1239 
   1240 //===----------------------------------------------------------------------===//
   1241 //                       GetElementPtrInst Implementation
   1242 //===----------------------------------------------------------------------===//
   1243 
   1244 void GetElementPtrInst::init(Value *Ptr, ArrayRef<Value *> IdxList,
   1245                              const Twine &Name) {
   1246   assert(NumOperands == 1 + IdxList.size() && "NumOperands not initialized?");
   1247   OperandList[0] = Ptr;
   1248   std::copy(IdxList.begin(), IdxList.end(), op_begin() + 1);
   1249   setName(Name);
   1250 }
   1251 
   1252 GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
   1253   : Instruction(GEPI.getType(), GetElementPtr,
   1254                 OperandTraits<GetElementPtrInst>::op_end(this)
   1255                 - GEPI.getNumOperands(),
   1256                 GEPI.getNumOperands()) {
   1257   std::copy(GEPI.op_begin(), GEPI.op_end(), op_begin());
   1258   SubclassOptionalData = GEPI.SubclassOptionalData;
   1259 }
   1260 
   1261 /// getIndexedType - Returns the type of the element that would be accessed with
   1262 /// a gep instruction with the specified parameters.
   1263 ///
   1264 /// The Idxs pointer should point to a continuous piece of memory containing the
   1265 /// indices, either as Value* or uint64_t.
   1266 ///
   1267 /// A null type is returned if the indices are invalid for the specified
   1268 /// pointer type.
   1269 ///
   1270 template <typename IndexTy>
   1271 static Type *getIndexedTypeInternal(Type *Agg, ArrayRef<IndexTy> IdxList) {
   1272   // Handle the special case of the empty set index set, which is always valid.
   1273   if (IdxList.empty())
   1274     return Agg;
   1275 
   1276   // If there is at least one index, the top level type must be sized, otherwise
   1277   // it cannot be 'stepped over'.
   1278   if (!Agg->isSized())
   1279     return nullptr;
   1280 
   1281   unsigned CurIdx = 1;
   1282   for (; CurIdx != IdxList.size(); ++CurIdx) {
   1283     CompositeType *CT = dyn_cast<CompositeType>(Agg);
   1284     if (!CT || CT->isPointerTy()) return nullptr;
   1285     IndexTy Index = IdxList[CurIdx];
   1286     if (!CT->indexValid(Index)) return nullptr;
   1287     Agg = CT->getTypeAtIndex(Index);
   1288   }
   1289   return CurIdx == IdxList.size() ? Agg : nullptr;
   1290 }
   1291 
   1292 Type *GetElementPtrInst::getIndexedType(Type *Ty, ArrayRef<Value *> IdxList) {
   1293   return getIndexedTypeInternal(Ty, IdxList);
   1294 }
   1295 
   1296 Type *GetElementPtrInst::getIndexedType(Type *Ty,
   1297                                         ArrayRef<Constant *> IdxList) {
   1298   return getIndexedTypeInternal(Ty, IdxList);
   1299 }
   1300 
   1301 Type *GetElementPtrInst::getIndexedType(Type *Ty, ArrayRef<uint64_t> IdxList) {
   1302   return getIndexedTypeInternal(Ty, IdxList);
   1303 }
   1304 
   1305 /// hasAllZeroIndices - Return true if all of the indices of this GEP are
   1306 /// zeros.  If so, the result pointer and the first operand have the same
   1307 /// value, just potentially different types.
   1308 bool GetElementPtrInst::hasAllZeroIndices() const {
   1309   for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
   1310     if (ConstantInt *CI = dyn_cast<ConstantInt>(getOperand(i))) {
   1311       if (!CI->isZero()) return false;
   1312     } else {
   1313       return false;
   1314     }
   1315   }
   1316   return true;
   1317 }
   1318 
   1319 /// hasAllConstantIndices - Return true if all of the indices of this GEP are
   1320 /// constant integers.  If so, the result pointer and the first operand have
   1321 /// a constant offset between them.
   1322 bool GetElementPtrInst::hasAllConstantIndices() const {
   1323   for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
   1324     if (!isa<ConstantInt>(getOperand(i)))
   1325       return false;
   1326   }
   1327   return true;
   1328 }
   1329 
   1330 void GetElementPtrInst::setIsInBounds(bool B) {
   1331   cast<GEPOperator>(this)->setIsInBounds(B);
   1332 }
   1333 
   1334 bool GetElementPtrInst::isInBounds() const {
   1335   return cast<GEPOperator>(this)->isInBounds();
   1336 }
   1337 
   1338 bool GetElementPtrInst::accumulateConstantOffset(const DataLayout &DL,
   1339                                                  APInt &Offset) const {
   1340   // Delegate to the generic GEPOperator implementation.
   1341   return cast<GEPOperator>(this)->accumulateConstantOffset(DL, Offset);
   1342 }
   1343 
   1344 //===----------------------------------------------------------------------===//
   1345 //                           ExtractElementInst Implementation
   1346 //===----------------------------------------------------------------------===//
   1347 
   1348 ExtractElementInst::ExtractElementInst(Value *Val, Value *Index,
   1349                                        const Twine &Name,
   1350                                        Instruction *InsertBef)
   1351   : Instruction(cast<VectorType>(Val->getType())->getElementType(),
   1352                 ExtractElement,
   1353                 OperandTraits<ExtractElementInst>::op_begin(this),
   1354                 2, InsertBef) {
   1355   assert(isValidOperands(Val, Index) &&
   1356          "Invalid extractelement instruction operands!");
   1357   Op<0>() = Val;
   1358   Op<1>() = Index;
   1359   setName(Name);
   1360 }
   1361 
   1362 ExtractElementInst::ExtractElementInst(Value *Val, Value *Index,
   1363                                        const Twine &Name,
   1364                                        BasicBlock *InsertAE)
   1365   : Instruction(cast<VectorType>(Val->getType())->getElementType(),
   1366                 ExtractElement,
   1367                 OperandTraits<ExtractElementInst>::op_begin(this),
   1368                 2, InsertAE) {
   1369   assert(isValidOperands(Val, Index) &&
   1370          "Invalid extractelement instruction operands!");
   1371 
   1372   Op<0>() = Val;
   1373   Op<1>() = Index;
   1374   setName(Name);
   1375 }
   1376 
   1377 
   1378 bool ExtractElementInst::isValidOperands(const Value *Val, const Value *Index) {
   1379   if (!Val->getType()->isVectorTy() || !Index->getType()->isIntegerTy())
   1380     return false;
   1381   return true;
   1382 }
   1383 
   1384 
   1385 //===----------------------------------------------------------------------===//
   1386 //                           InsertElementInst Implementation
   1387 //===----------------------------------------------------------------------===//
   1388 
   1389 InsertElementInst::InsertElementInst(Value *Vec, Value *Elt, Value *Index,
   1390                                      const Twine &Name,
   1391                                      Instruction *InsertBef)
   1392   : Instruction(Vec->getType(), InsertElement,
   1393                 OperandTraits<InsertElementInst>::op_begin(this),
   1394                 3, InsertBef) {
   1395   assert(isValidOperands(Vec, Elt, Index) &&
   1396          "Invalid insertelement instruction operands!");
   1397   Op<0>() = Vec;
   1398   Op<1>() = Elt;
   1399   Op<2>() = Index;
   1400   setName(Name);
   1401 }
   1402 
   1403 InsertElementInst::InsertElementInst(Value *Vec, Value *Elt, Value *Index,
   1404                                      const Twine &Name,
   1405                                      BasicBlock *InsertAE)
   1406   : Instruction(Vec->getType(), InsertElement,
   1407                 OperandTraits<InsertElementInst>::op_begin(this),
   1408                 3, InsertAE) {
   1409   assert(isValidOperands(Vec, Elt, Index) &&
   1410          "Invalid insertelement instruction operands!");
   1411 
   1412   Op<0>() = Vec;
   1413   Op<1>() = Elt;
   1414   Op<2>() = Index;
   1415   setName(Name);
   1416 }
   1417 
   1418 bool InsertElementInst::isValidOperands(const Value *Vec, const Value *Elt,
   1419                                         const Value *Index) {
   1420   if (!Vec->getType()->isVectorTy())
   1421     return false;   // First operand of insertelement must be vector type.
   1422 
   1423   if (Elt->getType() != cast<VectorType>(Vec->getType())->getElementType())
   1424     return false;// Second operand of insertelement must be vector element type.
   1425 
   1426   if (!Index->getType()->isIntegerTy())
   1427     return false;  // Third operand of insertelement must be i32.
   1428   return true;
   1429 }
   1430 
   1431 
   1432 //===----------------------------------------------------------------------===//
   1433 //                      ShuffleVectorInst Implementation
   1434 //===----------------------------------------------------------------------===//
   1435 
   1436 ShuffleVectorInst::ShuffleVectorInst(Value *V1, Value *V2, Value *Mask,
   1437                                      const Twine &Name,
   1438                                      Instruction *InsertBefore)
   1439 : Instruction(VectorType::get(cast<VectorType>(V1->getType())->getElementType(),
   1440                 cast<VectorType>(Mask->getType())->getNumElements()),
   1441               ShuffleVector,
   1442               OperandTraits<ShuffleVectorInst>::op_begin(this),
   1443               OperandTraits<ShuffleVectorInst>::operands(this),
   1444               InsertBefore) {
   1445   assert(isValidOperands(V1, V2, Mask) &&
   1446          "Invalid shuffle vector instruction operands!");
   1447   Op<0>() = V1;
   1448   Op<1>() = V2;
   1449   Op<2>() = Mask;
   1450   setName(Name);
   1451 }
   1452 
   1453 ShuffleVectorInst::ShuffleVectorInst(Value *V1, Value *V2, Value *Mask,
   1454                                      const Twine &Name,
   1455                                      BasicBlock *InsertAtEnd)
   1456 : Instruction(VectorType::get(cast<VectorType>(V1->getType())->getElementType(),
   1457                 cast<VectorType>(Mask->getType())->getNumElements()),
   1458               ShuffleVector,
   1459               OperandTraits<ShuffleVectorInst>::op_begin(this),
   1460               OperandTraits<ShuffleVectorInst>::operands(this),
   1461               InsertAtEnd) {
   1462   assert(isValidOperands(V1, V2, Mask) &&
   1463          "Invalid shuffle vector instruction operands!");
   1464 
   1465   Op<0>() = V1;
   1466   Op<1>() = V2;
   1467   Op<2>() = Mask;
   1468   setName(Name);
   1469 }
   1470 
   1471 bool ShuffleVectorInst::isValidOperands(const Value *V1, const Value *V2,
   1472                                         const Value *Mask) {
   1473   // V1 and V2 must be vectors of the same type.
   1474   if (!V1->getType()->isVectorTy() || V1->getType() != V2->getType())
   1475     return false;
   1476 
   1477   // Mask must be vector of i32.
   1478   VectorType *MaskTy = dyn_cast<VectorType>(Mask->getType());
   1479   if (!MaskTy || !MaskTy->getElementType()->isIntegerTy(32))
   1480     return false;
   1481 
   1482   // Check to see if Mask is valid.
   1483   if (isa<UndefValue>(Mask) || isa<ConstantAggregateZero>(Mask))
   1484     return true;
   1485 
   1486   if (const ConstantVector *MV = dyn_cast<ConstantVector>(Mask)) {
   1487     unsigned V1Size = cast<VectorType>(V1->getType())->getNumElements();
   1488     for (Value *Op : MV->operands()) {
   1489       if (ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {
   1490         if (CI->uge(V1Size*2))
   1491           return false;
   1492       } else if (!isa<UndefValue>(Op)) {
   1493         return false;
   1494       }
   1495     }
   1496     return true;
   1497   }
   1498 
   1499   if (const ConstantDataSequential *CDS =
   1500         dyn_cast<ConstantDataSequential>(Mask)) {
   1501     unsigned V1Size = cast<VectorType>(V1->getType())->getNumElements();
   1502     for (unsigned i = 0, e = MaskTy->getNumElements(); i != e; ++i)
   1503       if (CDS->getElementAsInteger(i) >= V1Size*2)
   1504         return false;
   1505     return true;
   1506   }
   1507 
   1508   // The bitcode reader can create a place holder for a forward reference
   1509   // used as the shuffle mask. When this occurs, the shuffle mask will
   1510   // fall into this case and fail. To avoid this error, do this bit of
   1511   // ugliness to allow such a mask pass.
   1512   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Mask))
   1513     if (CE->getOpcode() == Instruction::UserOp1)
   1514       return true;
   1515 
   1516   return false;
   1517 }
   1518 
   1519 /// getMaskValue - Return the index from the shuffle mask for the specified
   1520 /// output result.  This is either -1 if the element is undef or a number less
   1521 /// than 2*numelements.
   1522 int ShuffleVectorInst::getMaskValue(Constant *Mask, unsigned i) {
   1523   assert(i < Mask->getType()->getVectorNumElements() && "Index out of range");
   1524   if (ConstantDataSequential *CDS =dyn_cast<ConstantDataSequential>(Mask))
   1525     return CDS->getElementAsInteger(i);
   1526   Constant *C = Mask->getAggregateElement(i);
   1527   if (isa<UndefValue>(C))
   1528     return -1;
   1529   return cast<ConstantInt>(C)->getZExtValue();
   1530 }
   1531 
   1532 /// getShuffleMask - Return the full mask for this instruction, where each
   1533 /// element is the element number and undef's are returned as -1.
   1534 void ShuffleVectorInst::getShuffleMask(Constant *Mask,
   1535                                        SmallVectorImpl<int> &Result) {
   1536   unsigned NumElts = Mask->getType()->getVectorNumElements();
   1537 
   1538   if (ConstantDataSequential *CDS=dyn_cast<ConstantDataSequential>(Mask)) {
   1539     for (unsigned i = 0; i != NumElts; ++i)
   1540       Result.push_back(CDS->getElementAsInteger(i));
   1541     return;
   1542   }
   1543   for (unsigned i = 0; i != NumElts; ++i) {
   1544     Constant *C = Mask->getAggregateElement(i);
   1545     Result.push_back(isa<UndefValue>(C) ? -1 :
   1546                      cast<ConstantInt>(C)->getZExtValue());
   1547   }
   1548 }
   1549 
   1550 
   1551 //===----------------------------------------------------------------------===//
   1552 //                             InsertValueInst Class
   1553 //===----------------------------------------------------------------------===//
   1554 
   1555 void InsertValueInst::init(Value *Agg, Value *Val, ArrayRef<unsigned> Idxs,
   1556                            const Twine &Name) {
   1557   assert(NumOperands == 2 && "NumOperands not initialized?");
   1558 
   1559   // There's no fundamental reason why we require at least one index
   1560   // (other than weirdness with &*IdxBegin being invalid; see
   1561   // getelementptr's init routine for example). But there's no
   1562   // present need to support it.
   1563   assert(Idxs.size() > 0 && "InsertValueInst must have at least one index");
   1564 
   1565   assert(ExtractValueInst::getIndexedType(Agg->getType(), Idxs) ==
   1566          Val->getType() && "Inserted value must match indexed type!");
   1567   Op<0>() = Agg;
   1568   Op<1>() = Val;
   1569 
   1570   Indices.append(Idxs.begin(), Idxs.end());
   1571   setName(Name);
   1572 }
   1573 
   1574 InsertValueInst::InsertValueInst(const InsertValueInst &IVI)
   1575   : Instruction(IVI.getType(), InsertValue,
   1576                 OperandTraits<InsertValueInst>::op_begin(this), 2),
   1577     Indices(IVI.Indices) {
   1578   Op<0>() = IVI.getOperand(0);
   1579   Op<1>() = IVI.getOperand(1);
   1580   SubclassOptionalData = IVI.SubclassOptionalData;
   1581 }
   1582 
   1583 //===----------------------------------------------------------------------===//
   1584 //                             ExtractValueInst Class
   1585 //===----------------------------------------------------------------------===//
   1586 
   1587 void ExtractValueInst::init(ArrayRef<unsigned> Idxs, const Twine &Name) {
   1588   assert(NumOperands == 1 && "NumOperands not initialized?");
   1589 
   1590   // There's no fundamental reason why we require at least one index.
   1591   // But there's no present need to support it.
   1592   assert(Idxs.size() > 0 && "ExtractValueInst must have at least one index");
   1593 
   1594   Indices.append(Idxs.begin(), Idxs.end());
   1595   setName(Name);
   1596 }
   1597 
   1598 ExtractValueInst::ExtractValueInst(const ExtractValueInst &EVI)
   1599   : UnaryInstruction(EVI.getType(), ExtractValue, EVI.getOperand(0)),
   1600     Indices(EVI.Indices) {
   1601   SubclassOptionalData = EVI.SubclassOptionalData;
   1602 }
   1603 
   1604 // getIndexedType - Returns the type of the element that would be extracted
   1605 // with an extractvalue instruction with the specified parameters.
   1606 //
   1607 // A null type is returned if the indices are invalid for the specified
   1608 // pointer type.
   1609 //
   1610 Type *ExtractValueInst::getIndexedType(Type *Agg,
   1611                                        ArrayRef<unsigned> Idxs) {
   1612   for (unsigned Index : Idxs) {
   1613     // We can't use CompositeType::indexValid(Index) here.
   1614     // indexValid() always returns true for arrays because getelementptr allows
   1615     // out-of-bounds indices. Since we don't allow those for extractvalue and
   1616     // insertvalue we need to check array indexing manually.
   1617     // Since the only other types we can index into are struct types it's just
   1618     // as easy to check those manually as well.
   1619     if (ArrayType *AT = dyn_cast<ArrayType>(Agg)) {
   1620       if (Index >= AT->getNumElements())
   1621         return nullptr;
   1622     } else if (StructType *ST = dyn_cast<StructType>(Agg)) {
   1623       if (Index >= ST->getNumElements())
   1624         return nullptr;
   1625     } else {
   1626       // Not a valid type to index into.
   1627       return nullptr;
   1628     }
   1629 
   1630     Agg = cast<CompositeType>(Agg)->getTypeAtIndex(Index);
   1631   }
   1632   return const_cast<Type*>(Agg);
   1633 }
   1634 
   1635 //===----------------------------------------------------------------------===//
   1636 //                             BinaryOperator Class
   1637 //===----------------------------------------------------------------------===//
   1638 
   1639 BinaryOperator::BinaryOperator(BinaryOps iType, Value *S1, Value *S2,
   1640                                Type *Ty, const Twine &Name,
   1641                                Instruction *InsertBefore)
   1642   : Instruction(Ty, iType,
   1643                 OperandTraits<BinaryOperator>::op_begin(this),
   1644                 OperandTraits<BinaryOperator>::operands(this),
   1645                 InsertBefore) {
   1646   Op<0>() = S1;
   1647   Op<1>() = S2;
   1648   init(iType);
   1649   setName(Name);
   1650 }
   1651 
   1652 BinaryOperator::BinaryOperator(BinaryOps iType, Value *S1, Value *S2,
   1653                                Type *Ty, const Twine &Name,
   1654                                BasicBlock *InsertAtEnd)
   1655   : Instruction(Ty, iType,
   1656                 OperandTraits<BinaryOperator>::op_begin(this),
   1657                 OperandTraits<BinaryOperator>::operands(this),
   1658                 InsertAtEnd) {
   1659   Op<0>() = S1;
   1660   Op<1>() = S2;
   1661   init(iType);
   1662   setName(Name);
   1663 }
   1664 
   1665 
   1666 void BinaryOperator::init(BinaryOps iType) {
   1667   Value *LHS = getOperand(0), *RHS = getOperand(1);
   1668   (void)LHS; (void)RHS; // Silence warnings.
   1669   assert(LHS->getType() == RHS->getType() &&
   1670          "Binary operator operand types must match!");
   1671 #ifndef NDEBUG
   1672   switch (iType) {
   1673   case Add: case Sub:
   1674   case Mul:
   1675     assert(getType() == LHS->getType() &&
   1676            "Arithmetic operation should return same type as operands!");
   1677     assert(getType()->isIntOrIntVectorTy() &&
   1678            "Tried to create an integer operation on a non-integer type!");
   1679     break;
   1680   case FAdd: case FSub:
   1681   case FMul:
   1682     assert(getType() == LHS->getType() &&
   1683            "Arithmetic operation should return same type as operands!");
   1684     assert(getType()->isFPOrFPVectorTy() &&
   1685            "Tried to create a floating-point operation on a "
   1686            "non-floating-point type!");
   1687     break;
   1688   case UDiv:
   1689   case SDiv:
   1690     assert(getType() == LHS->getType() &&
   1691            "Arithmetic operation should return same type as operands!");
   1692     assert((getType()->isIntegerTy() || (getType()->isVectorTy() &&
   1693             cast<VectorType>(getType())->getElementType()->isIntegerTy())) &&
   1694            "Incorrect operand type (not integer) for S/UDIV");
   1695     break;
   1696   case FDiv:
   1697     assert(getType() == LHS->getType() &&
   1698            "Arithmetic operation should return same type as operands!");
   1699     assert(getType()->isFPOrFPVectorTy() &&
   1700            "Incorrect operand type (not floating point) for FDIV");
   1701     break;
   1702   case URem:
   1703   case SRem:
   1704     assert(getType() == LHS->getType() &&
   1705            "Arithmetic operation should return same type as operands!");
   1706     assert((getType()->isIntegerTy() || (getType()->isVectorTy() &&
   1707             cast<VectorType>(getType())->getElementType()->isIntegerTy())) &&
   1708            "Incorrect operand type (not integer) for S/UREM");
   1709     break;
   1710   case FRem:
   1711     assert(getType() == LHS->getType() &&
   1712            "Arithmetic operation should return same type as operands!");
   1713     assert(getType()->isFPOrFPVectorTy() &&
   1714            "Incorrect operand type (not floating point) for FREM");
   1715     break;
   1716   case Shl:
   1717   case LShr:
   1718   case AShr:
   1719     assert(getType() == LHS->getType() &&
   1720            "Shift operation should return same type as operands!");
   1721     assert((getType()->isIntegerTy() ||
   1722             (getType()->isVectorTy() &&
   1723              cast<VectorType>(getType())->getElementType()->isIntegerTy())) &&
   1724            "Tried to create a shift operation on a non-integral type!");
   1725     break;
   1726   case And: case Or:
   1727   case Xor:
   1728     assert(getType() == LHS->getType() &&
   1729            "Logical operation should return same type as operands!");
   1730     assert((getType()->isIntegerTy() ||
   1731             (getType()->isVectorTy() &&
   1732              cast<VectorType>(getType())->getElementType()->isIntegerTy())) &&
   1733            "Tried to create a logical operation on a non-integral type!");
   1734     break;
   1735   default:
   1736     break;
   1737   }
   1738 #endif
   1739 }
   1740 
   1741 BinaryOperator *BinaryOperator::Create(BinaryOps Op, Value *S1, Value *S2,
   1742                                        const Twine &Name,
   1743                                        Instruction *InsertBefore) {
   1744   assert(S1->getType() == S2->getType() &&
   1745          "Cannot create binary operator with two operands of differing type!");
   1746   return new BinaryOperator(Op, S1, S2, S1->getType(), Name, InsertBefore);
   1747 }
   1748 
   1749 BinaryOperator *BinaryOperator::Create(BinaryOps Op, Value *S1, Value *S2,
   1750                                        const Twine &Name,
   1751                                        BasicBlock *InsertAtEnd) {
   1752   BinaryOperator *Res = Create(Op, S1, S2, Name);
   1753   InsertAtEnd->getInstList().push_back(Res);
   1754   return Res;
   1755 }
   1756 
   1757 BinaryOperator *BinaryOperator::CreateNeg(Value *Op, const Twine &Name,
   1758                                           Instruction *InsertBefore) {
   1759   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1760   return new BinaryOperator(Instruction::Sub,
   1761                             zero, Op,
   1762                             Op->getType(), Name, InsertBefore);
   1763 }
   1764 
   1765 BinaryOperator *BinaryOperator::CreateNeg(Value *Op, const Twine &Name,
   1766                                           BasicBlock *InsertAtEnd) {
   1767   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1768   return new BinaryOperator(Instruction::Sub,
   1769                             zero, Op,
   1770                             Op->getType(), Name, InsertAtEnd);
   1771 }
   1772 
   1773 BinaryOperator *BinaryOperator::CreateNSWNeg(Value *Op, const Twine &Name,
   1774                                              Instruction *InsertBefore) {
   1775   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1776   return BinaryOperator::CreateNSWSub(zero, Op, Name, InsertBefore);
   1777 }
   1778 
   1779 BinaryOperator *BinaryOperator::CreateNSWNeg(Value *Op, const Twine &Name,
   1780                                              BasicBlock *InsertAtEnd) {
   1781   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1782   return BinaryOperator::CreateNSWSub(zero, Op, Name, InsertAtEnd);
   1783 }
   1784 
   1785 BinaryOperator *BinaryOperator::CreateNUWNeg(Value *Op, const Twine &Name,
   1786                                              Instruction *InsertBefore) {
   1787   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1788   return BinaryOperator::CreateNUWSub(zero, Op, Name, InsertBefore);
   1789 }
   1790 
   1791 BinaryOperator *BinaryOperator::CreateNUWNeg(Value *Op, const Twine &Name,
   1792                                              BasicBlock *InsertAtEnd) {
   1793   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1794   return BinaryOperator::CreateNUWSub(zero, Op, Name, InsertAtEnd);
   1795 }
   1796 
   1797 BinaryOperator *BinaryOperator::CreateFNeg(Value *Op, const Twine &Name,
   1798                                            Instruction *InsertBefore) {
   1799   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1800   return new BinaryOperator(Instruction::FSub, zero, Op,
   1801                             Op->getType(), Name, InsertBefore);
   1802 }
   1803 
   1804 BinaryOperator *BinaryOperator::CreateFNeg(Value *Op, const Twine &Name,
   1805                                            BasicBlock *InsertAtEnd) {
   1806   Value *zero = ConstantFP::getZeroValueForNegation(Op->getType());
   1807   return new BinaryOperator(Instruction::FSub, zero, Op,
   1808                             Op->getType(), Name, InsertAtEnd);
   1809 }
   1810 
   1811 BinaryOperator *BinaryOperator::CreateNot(Value *Op, const Twine &Name,
   1812                                           Instruction *InsertBefore) {
   1813   Constant *C = Constant::getAllOnesValue(Op->getType());
   1814   return new BinaryOperator(Instruction::Xor, Op, C,
   1815                             Op->getType(), Name, InsertBefore);
   1816 }
   1817 
   1818 BinaryOperator *BinaryOperator::CreateNot(Value *Op, const Twine &Name,
   1819                                           BasicBlock *InsertAtEnd) {
   1820   Constant *AllOnes = Constant::getAllOnesValue(Op->getType());
   1821   return new BinaryOperator(Instruction::Xor, Op, AllOnes,
   1822                             Op->getType(), Name, InsertAtEnd);
   1823 }
   1824 
   1825 
   1826 // isConstantAllOnes - Helper function for several functions below
   1827 static inline bool isConstantAllOnes(const Value *V) {
   1828   if (const Constant *C = dyn_cast<Constant>(V))
   1829     return C->isAllOnesValue();
   1830   return false;
   1831 }
   1832 
   1833 bool BinaryOperator::isNeg(const Value *V) {
   1834   if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(V))
   1835     if (Bop->getOpcode() == Instruction::Sub)
   1836       if (Constant* C = dyn_cast<Constant>(Bop->getOperand(0)))
   1837         return C->isNegativeZeroValue();
   1838   return false;
   1839 }
   1840 
   1841 bool BinaryOperator::isFNeg(const Value *V, bool IgnoreZeroSign) {
   1842   if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(V))
   1843     if (Bop->getOpcode() == Instruction::FSub)
   1844       if (Constant* C = dyn_cast<Constant>(Bop->getOperand(0))) {
   1845         if (!IgnoreZeroSign)
   1846           IgnoreZeroSign = cast<Instruction>(V)->hasNoSignedZeros();
   1847         return !IgnoreZeroSign ? C->isNegativeZeroValue() : C->isZeroValue();
   1848       }
   1849   return false;
   1850 }
   1851 
   1852 bool BinaryOperator::isNot(const Value *V) {
   1853   if (const BinaryOperator *Bop = dyn_cast<BinaryOperator>(V))
   1854     return (Bop->getOpcode() == Instruction::Xor &&
   1855             (isConstantAllOnes(Bop->getOperand(1)) ||
   1856              isConstantAllOnes(Bop->getOperand(0))));
   1857   return false;
   1858 }
   1859 
   1860 Value *BinaryOperator::getNegArgument(Value *BinOp) {
   1861   return cast<BinaryOperator>(BinOp)->getOperand(1);
   1862 }
   1863 
   1864 const Value *BinaryOperator::getNegArgument(const Value *BinOp) {
   1865   return getNegArgument(const_cast<Value*>(BinOp));
   1866 }
   1867 
   1868 Value *BinaryOperator::getFNegArgument(Value *BinOp) {
   1869   return cast<BinaryOperator>(BinOp)->getOperand(1);
   1870 }
   1871 
   1872 const Value *BinaryOperator::getFNegArgument(const Value *BinOp) {
   1873   return getFNegArgument(const_cast<Value*>(BinOp));
   1874 }
   1875 
   1876 Value *BinaryOperator::getNotArgument(Value *BinOp) {
   1877   assert(isNot(BinOp) && "getNotArgument on non-'not' instruction!");
   1878   BinaryOperator *BO = cast<BinaryOperator>(BinOp);
   1879   Value *Op0 = BO->getOperand(0);
   1880   Value *Op1 = BO->getOperand(1);
   1881   if (isConstantAllOnes(Op0)) return Op1;
   1882 
   1883   assert(isConstantAllOnes(Op1));
   1884   return Op0;
   1885 }
   1886 
   1887 const Value *BinaryOperator::getNotArgument(const Value *BinOp) {
   1888   return getNotArgument(const_cast<Value*>(BinOp));
   1889 }
   1890 
   1891 
   1892 // swapOperands - Exchange the two operands to this instruction.  This
   1893 // instruction is safe to use on any binary instruction and does not
   1894 // modify the semantics of the instruction.  If the instruction is
   1895 // order dependent (SetLT f.e.) the opcode is changed.
   1896 //
   1897 bool BinaryOperator::swapOperands() {
   1898   if (!isCommutative())
   1899     return true; // Can't commute operands
   1900   Op<0>().swap(Op<1>());
   1901   return false;
   1902 }
   1903 
   1904 void BinaryOperator::setHasNoUnsignedWrap(bool b) {
   1905   cast<OverflowingBinaryOperator>(this)->setHasNoUnsignedWrap(b);
   1906 }
   1907 
   1908 void BinaryOperator::setHasNoSignedWrap(bool b) {
   1909   cast<OverflowingBinaryOperator>(this)->setHasNoSignedWrap(b);
   1910 }
   1911 
   1912 void BinaryOperator::setIsExact(bool b) {
   1913   cast<PossiblyExactOperator>(this)->setIsExact(b);
   1914 }
   1915 
   1916 bool BinaryOperator::hasNoUnsignedWrap() const {
   1917   return cast<OverflowingBinaryOperator>(this)->hasNoUnsignedWrap();
   1918 }
   1919 
   1920 bool BinaryOperator::hasNoSignedWrap() const {
   1921   return cast<OverflowingBinaryOperator>(this)->hasNoSignedWrap();
   1922 }
   1923 
   1924 bool BinaryOperator::isExact() const {
   1925   return cast<PossiblyExactOperator>(this)->isExact();
   1926 }
   1927 
   1928 void BinaryOperator::copyIRFlags(const Value *V) {
   1929   // Copy the wrapping flags.
   1930   if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
   1931     setHasNoSignedWrap(OB->hasNoSignedWrap());
   1932     setHasNoUnsignedWrap(OB->hasNoUnsignedWrap());
   1933   }
   1934 
   1935   // Copy the exact flag.
   1936   if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
   1937     setIsExact(PE->isExact());
   1938 
   1939   // Copy the fast-math flags.
   1940   if (auto *FP = dyn_cast<FPMathOperator>(V))
   1941     copyFastMathFlags(FP->getFastMathFlags());
   1942 }
   1943 
   1944 void BinaryOperator::andIRFlags(const Value *V) {
   1945   if (auto *OB = dyn_cast<OverflowingBinaryOperator>(V)) {
   1946     setHasNoSignedWrap(hasNoSignedWrap() & OB->hasNoSignedWrap());
   1947     setHasNoUnsignedWrap(hasNoUnsignedWrap() & OB->hasNoUnsignedWrap());
   1948   }
   1949 
   1950   if (auto *PE = dyn_cast<PossiblyExactOperator>(V))
   1951     setIsExact(isExact() & PE->isExact());
   1952 
   1953   if (auto *FP = dyn_cast<FPMathOperator>(V)) {
   1954     FastMathFlags FM = getFastMathFlags();
   1955     FM &= FP->getFastMathFlags();
   1956     copyFastMathFlags(FM);
   1957   }
   1958 }
   1959 
   1960 
   1961 //===----------------------------------------------------------------------===//
   1962 //                             FPMathOperator Class
   1963 //===----------------------------------------------------------------------===//
   1964 
   1965 /// getFPAccuracy - Get the maximum error permitted by this operation in ULPs.
   1966 /// An accuracy of 0.0 means that the operation should be performed with the
   1967 /// default precision.
   1968 float FPMathOperator::getFPAccuracy() const {
   1969   const MDNode *MD =
   1970       cast<Instruction>(this)->getMetadata(LLVMContext::MD_fpmath);
   1971   if (!MD)
   1972     return 0.0;
   1973   ConstantFP *Accuracy = mdconst::extract<ConstantFP>(MD->getOperand(0));
   1974   return Accuracy->getValueAPF().convertToFloat();
   1975 }
   1976 
   1977 
   1978 //===----------------------------------------------------------------------===//
   1979 //                                CastInst Class
   1980 //===----------------------------------------------------------------------===//
   1981 
   1982 void CastInst::anchor() {}
   1983 
   1984 // Just determine if this cast only deals with integral->integral conversion.
   1985 bool CastInst::isIntegerCast() const {
   1986   switch (getOpcode()) {
   1987     default: return false;
   1988     case Instruction::ZExt:
   1989     case Instruction::SExt:
   1990     case Instruction::Trunc:
   1991       return true;
   1992     case Instruction::BitCast:
   1993       return getOperand(0)->getType()->isIntegerTy() &&
   1994         getType()->isIntegerTy();
   1995   }
   1996 }
   1997 
   1998 bool CastInst::isLosslessCast() const {
   1999   // Only BitCast can be lossless, exit fast if we're not BitCast
   2000   if (getOpcode() != Instruction::BitCast)
   2001     return false;
   2002 
   2003   // Identity cast is always lossless
   2004   Type* SrcTy = getOperand(0)->getType();
   2005   Type* DstTy = getType();
   2006   if (SrcTy == DstTy)
   2007     return true;
   2008 
   2009   // Pointer to pointer is always lossless.
   2010   if (SrcTy->isPointerTy())
   2011     return DstTy->isPointerTy();
   2012   return false;  // Other types have no identity values
   2013 }
   2014 
   2015 /// This function determines if the CastInst does not require any bits to be
   2016 /// changed in order to effect the cast. Essentially, it identifies cases where
   2017 /// no code gen is necessary for the cast, hence the name no-op cast.  For
   2018 /// example, the following are all no-op casts:
   2019 /// # bitcast i32* %x to i8*
   2020 /// # bitcast <2 x i32> %x to <4 x i16>
   2021 /// # ptrtoint i32* %x to i32     ; on 32-bit plaforms only
   2022 /// @brief Determine if the described cast is a no-op.
   2023 bool CastInst::isNoopCast(Instruction::CastOps Opcode,
   2024                           Type *SrcTy,
   2025                           Type *DestTy,
   2026                           Type *IntPtrTy) {
   2027   switch (Opcode) {
   2028     default: llvm_unreachable("Invalid CastOp");
   2029     case Instruction::Trunc:
   2030     case Instruction::ZExt:
   2031     case Instruction::SExt:
   2032     case Instruction::FPTrunc:
   2033     case Instruction::FPExt:
   2034     case Instruction::UIToFP:
   2035     case Instruction::SIToFP:
   2036     case Instruction::FPToUI:
   2037     case Instruction::FPToSI:
   2038     case Instruction::AddrSpaceCast:
   2039       // TODO: Target informations may give a more accurate answer here.
   2040       return false;
   2041     case Instruction::BitCast:
   2042       return true;  // BitCast never modifies bits.
   2043     case Instruction::PtrToInt:
   2044       return IntPtrTy->getScalarSizeInBits() ==
   2045              DestTy->getScalarSizeInBits();
   2046     case Instruction::IntToPtr:
   2047       return IntPtrTy->getScalarSizeInBits() ==
   2048              SrcTy->getScalarSizeInBits();
   2049   }
   2050 }
   2051 
   2052 /// @brief Determine if a cast is a no-op.
   2053 bool CastInst::isNoopCast(Type *IntPtrTy) const {
   2054   return isNoopCast(getOpcode(), getOperand(0)->getType(), getType(), IntPtrTy);
   2055 }
   2056 
   2057 bool CastInst::isNoopCast(const DataLayout &DL) const {
   2058   Type *PtrOpTy = nullptr;
   2059   if (getOpcode() == Instruction::PtrToInt)
   2060     PtrOpTy = getOperand(0)->getType();
   2061   else if (getOpcode() == Instruction::IntToPtr)
   2062     PtrOpTy = getType();
   2063 
   2064   Type *IntPtrTy =
   2065       PtrOpTy ? DL.getIntPtrType(PtrOpTy) : DL.getIntPtrType(getContext(), 0);
   2066 
   2067   return isNoopCast(getOpcode(), getOperand(0)->getType(), getType(), IntPtrTy);
   2068 }
   2069 
   2070 /// This function determines if a pair of casts can be eliminated and what
   2071 /// opcode should be used in the elimination. This assumes that there are two
   2072 /// instructions like this:
   2073 /// *  %F = firstOpcode SrcTy %x to MidTy
   2074 /// *  %S = secondOpcode MidTy %F to DstTy
   2075 /// The function returns a resultOpcode so these two casts can be replaced with:
   2076 /// *  %Replacement = resultOpcode %SrcTy %x to DstTy
   2077 /// If no such cast is permited, the function returns 0.
   2078 unsigned CastInst::isEliminableCastPair(
   2079   Instruction::CastOps firstOp, Instruction::CastOps secondOp,
   2080   Type *SrcTy, Type *MidTy, Type *DstTy, Type *SrcIntPtrTy, Type *MidIntPtrTy,
   2081   Type *DstIntPtrTy) {
   2082   // Define the 144 possibilities for these two cast instructions. The values
   2083   // in this matrix determine what to do in a given situation and select the
   2084   // case in the switch below.  The rows correspond to firstOp, the columns
   2085   // correspond to secondOp.  In looking at the table below, keep in  mind
   2086   // the following cast properties:
   2087   //
   2088   //          Size Compare       Source               Destination
   2089   // Operator  Src ? Size   Type       Sign         Type       Sign
   2090   // -------- ------------ -------------------   ---------------------
   2091   // TRUNC         >       Integer      Any        Integral     Any
   2092   // ZEXT          <       Integral   Unsigned     Integer      Any
   2093   // SEXT          <       Integral    Signed      Integer      Any
   2094   // FPTOUI       n/a      FloatPt      n/a        Integral   Unsigned
   2095   // FPTOSI       n/a      FloatPt      n/a        Integral    Signed
   2096   // UITOFP       n/a      Integral   Unsigned     FloatPt      n/a
   2097   // SITOFP       n/a      Integral    Signed      FloatPt      n/a
   2098   // FPTRUNC       >       FloatPt      n/a        FloatPt      n/a
   2099   // FPEXT         <       FloatPt      n/a        FloatPt      n/a
   2100   // PTRTOINT     n/a      Pointer      n/a        Integral   Unsigned
   2101   // INTTOPTR     n/a      Integral   Unsigned     Pointer      n/a
   2102   // BITCAST       =       FirstClass   n/a       FirstClass    n/a
   2103   // ADDRSPCST    n/a      Pointer      n/a        Pointer      n/a
   2104   //
   2105   // NOTE: some transforms are safe, but we consider them to be non-profitable.
   2106   // For example, we could merge "fptoui double to i32" + "zext i32 to i64",
   2107   // into "fptoui double to i64", but this loses information about the range
   2108   // of the produced value (we no longer know the top-part is all zeros).
   2109   // Further this conversion is often much more expensive for typical hardware,
   2110   // and causes issues when building libgcc.  We disallow fptosi+sext for the
   2111   // same reason.
   2112   const unsigned numCastOps =
   2113     Instruction::CastOpsEnd - Instruction::CastOpsBegin;
   2114   static const uint8_t CastResults[numCastOps][numCastOps] = {
   2115     // T        F  F  U  S  F  F  P  I  B  A  -+
   2116     // R  Z  S  P  P  I  I  T  P  2  N  T  S   |
   2117     // U  E  E  2  2  2  2  R  E  I  T  C  C   +- secondOp
   2118     // N  X  X  U  S  F  F  N  X  N  2  V  V   |
   2119     // C  T  T  I  I  P  P  C  T  T  P  T  T  -+
   2120     {  1, 0, 0,99,99, 0, 0,99,99,99, 0, 3, 0}, // Trunc         -+
   2121     {  8, 1, 9,99,99, 2, 0,99,99,99, 2, 3, 0}, // ZExt           |
   2122     {  8, 0, 1,99,99, 0, 2,99,99,99, 0, 3, 0}, // SExt           |
   2123     {  0, 0, 0,99,99, 0, 0,99,99,99, 0, 3, 0}, // FPToUI         |
   2124     {  0, 0, 0,99,99, 0, 0,99,99,99, 0, 3, 0}, // FPToSI         |
   2125     { 99,99,99, 0, 0,99,99, 0, 0,99,99, 4, 0}, // UIToFP         +- firstOp
   2126     { 99,99,99, 0, 0,99,99, 0, 0,99,99, 4, 0}, // SIToFP         |
   2127     { 99,99,99, 0, 0,99,99, 1, 0,99,99, 4, 0}, // FPTrunc        |
   2128     { 99,99,99, 2, 2,99,99,10, 2,99,99, 4, 0}, // FPExt          |
   2129     {  1, 0, 0,99,99, 0, 0,99,99,99, 7, 3, 0}, // PtrToInt       |
   2130     { 99,99,99,99,99,99,99,99,99,11,99,15, 0}, // IntToPtr       |
   2131     {  5, 5, 5, 6, 6, 5, 5, 6, 6,16, 5, 1,14}, // BitCast        |
   2132     {  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,13,12}, // AddrSpaceCast -+
   2133   };
   2134 
   2135   // If either of the casts are a bitcast from scalar to vector, disallow the
   2136   // merging. However, bitcast of A->B->A are allowed.
   2137   bool isFirstBitcast  = (firstOp == Instruction::BitCast);
   2138   bool isSecondBitcast = (secondOp == Instruction::BitCast);
   2139   bool chainedBitcast  = (SrcTy == DstTy && isFirstBitcast && isSecondBitcast);
   2140 
   2141   // Check if any of the bitcasts convert scalars<->vectors.
   2142   if ((isFirstBitcast  && isa<VectorType>(SrcTy) != isa<VectorType>(MidTy)) ||
   2143       (isSecondBitcast && isa<VectorType>(MidTy) != isa<VectorType>(DstTy)))
   2144     // Unless we are bitcasing to the original type, disallow optimizations.
   2145     if (!chainedBitcast) return 0;
   2146 
   2147   int ElimCase = CastResults[firstOp-Instruction::CastOpsBegin]
   2148                             [secondOp-Instruction::CastOpsBegin];
   2149   switch (ElimCase) {
   2150     case 0:
   2151       // Categorically disallowed.
   2152       return 0;
   2153     case 1:
   2154       // Allowed, use first cast's opcode.
   2155       return firstOp;
   2156     case 2:
   2157       // Allowed, use second cast's opcode.
   2158       return secondOp;
   2159     case 3:
   2160       // No-op cast in second op implies firstOp as long as the DestTy
   2161       // is integer and we are not converting between a vector and a
   2162       // non-vector type.
   2163       if (!SrcTy->isVectorTy() && DstTy->isIntegerTy())
   2164         return firstOp;
   2165       return 0;
   2166     case 4:
   2167       // No-op cast in second op implies firstOp as long as the DestTy
   2168       // is floating point.
   2169       if (DstTy->isFloatingPointTy())
   2170         return firstOp;
   2171       return 0;
   2172     case 5:
   2173       // No-op cast in first op implies secondOp as long as the SrcTy
   2174       // is an integer.
   2175       if (SrcTy->isIntegerTy())
   2176         return secondOp;
   2177       return 0;
   2178     case 6:
   2179       // No-op cast in first op implies secondOp as long as the SrcTy
   2180       // is a floating point.
   2181       if (SrcTy->isFloatingPointTy())
   2182         return secondOp;
   2183       return 0;
   2184     case 7: {
   2185       // Cannot simplify if address spaces are different!
   2186       if (SrcTy->getPointerAddressSpace() != DstTy->getPointerAddressSpace())
   2187         return 0;
   2188 
   2189       unsigned MidSize = MidTy->getScalarSizeInBits();
   2190       // We can still fold this without knowing the actual sizes as long we
   2191       // know that the intermediate pointer is the largest possible
   2192       // pointer size.
   2193       // FIXME: Is this always true?
   2194       if (MidSize == 64)
   2195         return Instruction::BitCast;
   2196 
   2197       // ptrtoint, inttoptr -> bitcast (ptr -> ptr) if int size is >= ptr size.
   2198       if (!SrcIntPtrTy || DstIntPtrTy != SrcIntPtrTy)
   2199         return 0;
   2200       unsigned PtrSize = SrcIntPtrTy->getScalarSizeInBits();
   2201       if (MidSize >= PtrSize)
   2202         return Instruction::BitCast;
   2203       return 0;
   2204     }
   2205     case 8: {
   2206       // ext, trunc -> bitcast,    if the SrcTy and DstTy are same size
   2207       // ext, trunc -> ext,        if sizeof(SrcTy) < sizeof(DstTy)
   2208       // ext, trunc -> trunc,      if sizeof(SrcTy) > sizeof(DstTy)
   2209       unsigned SrcSize = SrcTy->getScalarSizeInBits();
   2210       unsigned DstSize = DstTy->getScalarSizeInBits();
   2211       if (SrcSize == DstSize)
   2212         return Instruction::BitCast;
   2213       else if (SrcSize < DstSize)
   2214         return firstOp;
   2215       return secondOp;
   2216     }
   2217     case 9:
   2218       // zext, sext -> zext, because sext can't sign extend after zext
   2219       return Instruction::ZExt;
   2220     case 10:
   2221       // fpext followed by ftrunc is allowed if the bit size returned to is
   2222       // the same as the original, in which case its just a bitcast
   2223       if (SrcTy == DstTy)
   2224         return Instruction::BitCast;
   2225       return 0; // If the types are not the same we can't eliminate it.
   2226     case 11: {
   2227       // inttoptr, ptrtoint -> bitcast if SrcSize<=PtrSize and SrcSize==DstSize
   2228       if (!MidIntPtrTy)
   2229         return 0;
   2230       unsigned PtrSize = MidIntPtrTy->getScalarSizeInBits();
   2231       unsigned SrcSize = SrcTy->getScalarSizeInBits();
   2232       unsigned DstSize = DstTy->getScalarSizeInBits();
   2233       if (SrcSize <= PtrSize && SrcSize == DstSize)
   2234         return Instruction::BitCast;
   2235       return 0;
   2236     }
   2237     case 12: {
   2238       // addrspacecast, addrspacecast -> bitcast,       if SrcAS == DstAS
   2239       // addrspacecast, addrspacecast -> addrspacecast, if SrcAS != DstAS
   2240       if (SrcTy->getPointerAddressSpace() != DstTy->getPointerAddressSpace())
   2241         return Instruction::AddrSpaceCast;
   2242       return Instruction::BitCast;
   2243     }
   2244     case 13:
   2245       // FIXME: this state can be merged with (1), but the following assert
   2246       // is useful to check the correcteness of the sequence due to semantic
   2247       // change of bitcast.
   2248       assert(
   2249         SrcTy->isPtrOrPtrVectorTy() &&
   2250         MidTy->isPtrOrPtrVectorTy() &&
   2251         DstTy->isPtrOrPtrVectorTy() &&
   2252         SrcTy->getPointerAddressSpace() != MidTy->getPointerAddressSpace() &&
   2253         MidTy->getPointerAddressSpace() == DstTy->getPointerAddressSpace() &&
   2254         "Illegal addrspacecast, bitcast sequence!");
   2255       // Allowed, use first cast's opcode
   2256       return firstOp;
   2257     case 14:
   2258       // bitcast, addrspacecast -> addrspacecast if the element type of
   2259       // bitcast's source is the same as that of addrspacecast's destination.
   2260       if (SrcTy->getPointerElementType() == DstTy->getPointerElementType())
   2261         return Instruction::AddrSpaceCast;
   2262       return 0;
   2263 
   2264     case 15:
   2265       // FIXME: this state can be merged with (1), but the following assert
   2266       // is useful to check the correcteness of the sequence due to semantic
   2267       // change of bitcast.
   2268       assert(
   2269         SrcTy->isIntOrIntVectorTy() &&
   2270         MidTy->isPtrOrPtrVectorTy() &&
   2271         DstTy->isPtrOrPtrVectorTy() &&
   2272         MidTy->getPointerAddressSpace() == DstTy->getPointerAddressSpace() &&
   2273         "Illegal inttoptr, bitcast sequence!");
   2274       // Allowed, use first cast's opcode
   2275       return firstOp;
   2276     case 16:
   2277       // FIXME: this state can be merged with (2), but the following assert
   2278       // is useful to check the correcteness of the sequence due to semantic
   2279       // change of bitcast.
   2280       assert(
   2281         SrcTy->isPtrOrPtrVectorTy() &&
   2282         MidTy->isPtrOrPtrVectorTy() &&
   2283         DstTy->isIntOrIntVectorTy() &&
   2284         SrcTy->getPointerAddressSpace() == MidTy->getPointerAddressSpace() &&
   2285         "Illegal bitcast, ptrtoint sequence!");
   2286       // Allowed, use second cast's opcode
   2287       return secondOp;
   2288     case 99:
   2289       // Cast combination can't happen (error in input). This is for all cases
   2290       // where the MidTy is not the same for the two cast instructions.
   2291       llvm_unreachable("Invalid Cast Combination");
   2292     default:
   2293       llvm_unreachable("Error in CastResults table!!!");
   2294   }
   2295 }
   2296 
   2297 CastInst *CastInst::Create(Instruction::CastOps op, Value *S, Type *Ty,
   2298   const Twine &Name, Instruction *InsertBefore) {
   2299   assert(castIsValid(op, S, Ty) && "Invalid cast!");
   2300   // Construct and return the appropriate CastInst subclass
   2301   switch (op) {
   2302   case Trunc:         return new TruncInst         (S, Ty, Name, InsertBefore);
   2303   case ZExt:          return new ZExtInst          (S, Ty, Name, InsertBefore);
   2304   case SExt:          return new SExtInst          (S, Ty, Name, InsertBefore);
   2305   case FPTrunc:       return new FPTruncInst       (S, Ty, Name, InsertBefore);
   2306   case FPExt:         return new FPExtInst         (S, Ty, Name, InsertBefore);
   2307   case UIToFP:        return new UIToFPInst        (S, Ty, Name, InsertBefore);
   2308   case SIToFP:        return new SIToFPInst        (S, Ty, Name, InsertBefore);
   2309   case FPToUI:        return new FPToUIInst        (S, Ty, Name, InsertBefore);
   2310   case FPToSI:        return new FPToSIInst        (S, Ty, Name, InsertBefore);
   2311   case PtrToInt:      return new PtrToIntInst      (S, Ty, Name, InsertBefore);
   2312   case IntToPtr:      return new IntToPtrInst      (S, Ty, Name, InsertBefore);
   2313   case BitCast:       return new BitCastInst       (S, Ty, Name, InsertBefore);
   2314   case AddrSpaceCast: return new AddrSpaceCastInst (S, Ty, Name, InsertBefore);
   2315   default: llvm_unreachable("Invalid opcode provided");
   2316   }
   2317 }
   2318 
   2319 CastInst *CastInst::Create(Instruction::CastOps op, Value *S, Type *Ty,
   2320   const Twine &Name, BasicBlock *InsertAtEnd) {
   2321   assert(castIsValid(op, S, Ty) && "Invalid cast!");
   2322   // Construct and return the appropriate CastInst subclass
   2323   switch (op) {
   2324   case Trunc:         return new TruncInst         (S, Ty, Name, InsertAtEnd);
   2325   case ZExt:          return new ZExtInst          (S, Ty, Name, InsertAtEnd);
   2326   case SExt:          return new SExtInst          (S, Ty, Name, InsertAtEnd);
   2327   case FPTrunc:       return new FPTruncInst       (S, Ty, Name, InsertAtEnd);
   2328   case FPExt:         return new FPExtInst         (S, Ty, Name, InsertAtEnd);
   2329   case UIToFP:        return new UIToFPInst        (S, Ty, Name, InsertAtEnd);
   2330   case SIToFP:        return new SIToFPInst        (S, Ty, Name, InsertAtEnd);
   2331   case FPToUI:        return new FPToUIInst        (S, Ty, Name, InsertAtEnd);
   2332   case FPToSI:        return new FPToSIInst        (S, Ty, Name, InsertAtEnd);
   2333   case PtrToInt:      return new PtrToIntInst      (S, Ty, Name, InsertAtEnd);
   2334   case IntToPtr:      return new IntToPtrInst      (S, Ty, Name, InsertAtEnd);
   2335   case BitCast:       return new BitCastInst       (S, Ty, Name, InsertAtEnd);
   2336   case AddrSpaceCast: return new AddrSpaceCastInst (S, Ty, Name, InsertAtEnd);
   2337   default: llvm_unreachable("Invalid opcode provided");
   2338   }
   2339 }
   2340 
   2341 CastInst *CastInst::CreateZExtOrBitCast(Value *S, Type *Ty,
   2342                                         const Twine &Name,
   2343                                         Instruction *InsertBefore) {
   2344   if (S->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
   2345     return Create(Instruction::BitCast, S, Ty, Name, InsertBefore);
   2346   return Create(Instruction::ZExt, S, Ty, Name, InsertBefore);
   2347 }
   2348 
   2349 CastInst *CastInst::CreateZExtOrBitCast(Value *S, Type *Ty,
   2350                                         const Twine &Name,
   2351                                         BasicBlock *InsertAtEnd) {
   2352   if (S->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
   2353     return Create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
   2354   return Create(Instruction::ZExt, S, Ty, Name, InsertAtEnd);
   2355 }
   2356 
   2357 CastInst *CastInst::CreateSExtOrBitCast(Value *S, Type *Ty,
   2358                                         const Twine &Name,
   2359                                         Instruction *InsertBefore) {
   2360   if (S->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
   2361     return Create(Instruction::BitCast, S, Ty, Name, InsertBefore);
   2362   return Create(Instruction::SExt, S, Ty, Name, InsertBefore);
   2363 }
   2364 
   2365 CastInst *CastInst::CreateSExtOrBitCast(Value *S, Type *Ty,
   2366                                         const Twine &Name,
   2367                                         BasicBlock *InsertAtEnd) {
   2368   if (S->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
   2369     return Create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
   2370   return Create(Instruction::SExt, S, Ty, Name, InsertAtEnd);
   2371 }
   2372 
   2373 CastInst *CastInst::CreateTruncOrBitCast(Value *S, Type *Ty,
   2374                                          const Twine &Name,
   2375                                          Instruction *InsertBefore) {
   2376   if (S->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
   2377     return Create(Instruction::BitCast, S, Ty, Name, InsertBefore);
   2378   return Create(Instruction::Trunc, S, Ty, Name, InsertBefore);
   2379 }
   2380 
   2381 CastInst *CastInst::CreateTruncOrBitCast(Value *S, Type *Ty,
   2382                                          const Twine &Name,
   2383                                          BasicBlock *InsertAtEnd) {
   2384   if (S->getType()->getScalarSizeInBits() == Ty->getScalarSizeInBits())
   2385     return Create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
   2386   return Create(Instruction::Trunc, S, Ty, Name, InsertAtEnd);
   2387 }
   2388 
   2389 CastInst *CastInst::CreatePointerCast(Value *S, Type *Ty,
   2390                                       const Twine &Name,
   2391                                       BasicBlock *InsertAtEnd) {
   2392   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
   2393   assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
   2394          "Invalid cast");
   2395   assert(Ty->isVectorTy() == S->getType()->isVectorTy() && "Invalid cast");
   2396   assert((!Ty->isVectorTy() ||
   2397           Ty->getVectorNumElements() == S->getType()->getVectorNumElements()) &&
   2398          "Invalid cast");
   2399 
   2400   if (Ty->isIntOrIntVectorTy())
   2401     return Create(Instruction::PtrToInt, S, Ty, Name, InsertAtEnd);
   2402 
   2403   return CreatePointerBitCastOrAddrSpaceCast(S, Ty, Name, InsertAtEnd);
   2404 }
   2405 
   2406 /// @brief Create a BitCast or a PtrToInt cast instruction
   2407 CastInst *CastInst::CreatePointerCast(Value *S, Type *Ty,
   2408                                       const Twine &Name,
   2409                                       Instruction *InsertBefore) {
   2410   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
   2411   assert((Ty->isIntOrIntVectorTy() || Ty->isPtrOrPtrVectorTy()) &&
   2412          "Invalid cast");
   2413   assert(Ty->isVectorTy() == S->getType()->isVectorTy() && "Invalid cast");
   2414   assert((!Ty->isVectorTy() ||
   2415           Ty->getVectorNumElements() == S->getType()->getVectorNumElements()) &&
   2416          "Invalid cast");
   2417 
   2418   if (Ty->isIntOrIntVectorTy())
   2419     return Create(Instruction::PtrToInt, S, Ty, Name, InsertBefore);
   2420 
   2421   return CreatePointerBitCastOrAddrSpaceCast(S, Ty, Name, InsertBefore);
   2422 }
   2423 
   2424 CastInst *CastInst::CreatePointerBitCastOrAddrSpaceCast(
   2425   Value *S, Type *Ty,
   2426   const Twine &Name,
   2427   BasicBlock *InsertAtEnd) {
   2428   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
   2429   assert(Ty->isPtrOrPtrVectorTy() && "Invalid cast");
   2430 
   2431   if (S->getType()->getPointerAddressSpace() != Ty->getPointerAddressSpace())
   2432     return Create(Instruction::AddrSpaceCast, S, Ty, Name, InsertAtEnd);
   2433 
   2434   return Create(Instruction::BitCast, S, Ty, Name, InsertAtEnd);
   2435 }
   2436 
   2437 CastInst *CastInst::CreatePointerBitCastOrAddrSpaceCast(
   2438   Value *S, Type *Ty,
   2439   const Twine &Name,
   2440   Instruction *InsertBefore) {
   2441   assert(S->getType()->isPtrOrPtrVectorTy() && "Invalid cast");
   2442   assert(Ty->isPtrOrPtrVectorTy() && "Invalid cast");
   2443 
   2444   if (S->getType()->getPointerAddressSpace() != Ty->getPointerAddressSpace())
   2445     return Create(Instruction::AddrSpaceCast, S, Ty, Name, InsertBefore);
   2446 
   2447   return Create(Instruction::BitCast, S, Ty, Name, InsertBefore);
   2448 }
   2449 
   2450 CastInst *CastInst::CreateBitOrPointerCast(Value *S, Type *Ty,
   2451                                            const Twine &Name,
   2452                                            Instruction *InsertBefore) {
   2453   if (S->getType()->isPointerTy() && Ty->isIntegerTy())
   2454     return Create(Instruction::PtrToInt, S, Ty, Name, InsertBefore);
   2455   if (S->getType()->isIntegerTy() && Ty->isPointerTy())
   2456     return Create(Instruction::IntToPtr, S, Ty, Name, InsertBefore);
   2457 
   2458   return Create(Instruction::BitCast, S, Ty, Name, InsertBefore);
   2459 }
   2460 
   2461 CastInst *CastInst::CreateIntegerCast(Value *C, Type *Ty,
   2462                                       bool isSigned, const Twine &Name,
   2463                                       Instruction *InsertBefore) {
   2464   assert(C->getType()->isIntOrIntVectorTy() && Ty->isIntOrIntVectorTy() &&
   2465          "Invalid integer cast");
   2466   unsigned SrcBits = C->getType()->getScalarSizeInBits();
   2467   unsigned DstBits = Ty->getScalarSizeInBits();
   2468   Instruction::CastOps opcode =
   2469     (SrcBits == DstBits ? Instruction::BitCast :
   2470      (SrcBits > DstBits ? Instruction::Trunc :
   2471       (isSigned ? Instruction::SExt : Instruction::ZExt)));
   2472   return Create(opcode, C, Ty, Name, InsertBefore);
   2473 }
   2474 
   2475 CastInst *CastInst::CreateIntegerCast(Value *C, Type *Ty,
   2476                                       bool isSigned, const Twine &Name,
   2477                                       BasicBlock *InsertAtEnd) {
   2478   assert(C->getType()->isIntOrIntVectorTy() && Ty->isIntOrIntVectorTy() &&
   2479          "Invalid cast");
   2480   unsigned SrcBits = C->getType()->getScalarSizeInBits();
   2481   unsigned DstBits = Ty->getScalarSizeInBits();
   2482   Instruction::CastOps opcode =
   2483     (SrcBits == DstBits ? Instruction::BitCast :
   2484      (SrcBits > DstBits ? Instruction::Trunc :
   2485       (isSigned ? Instruction::SExt : Instruction::ZExt)));
   2486   return Create(opcode, C, Ty, Name, InsertAtEnd);
   2487 }
   2488 
   2489 CastInst *CastInst::CreateFPCast(Value *C, Type *Ty,
   2490                                  const Twine &Name,
   2491                                  Instruction *InsertBefore) {
   2492   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
   2493          "Invalid cast");
   2494   unsigned SrcBits = C->getType()->getScalarSizeInBits();
   2495   unsigned DstBits = Ty->getScalarSizeInBits();
   2496   Instruction::CastOps opcode =
   2497     (SrcBits == DstBits ? Instruction::BitCast :
   2498      (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt));
   2499   return Create(opcode, C, Ty, Name, InsertBefore);
   2500 }
   2501 
   2502 CastInst *CastInst::CreateFPCast(Value *C, Type *Ty,
   2503                                  const Twine &Name,
   2504                                  BasicBlock *InsertAtEnd) {
   2505   assert(C->getType()->isFPOrFPVectorTy() && Ty->isFPOrFPVectorTy() &&
   2506          "Invalid cast");
   2507   unsigned SrcBits = C->getType()->getScalarSizeInBits();
   2508   unsigned DstBits = Ty->getScalarSizeInBits();
   2509   Instruction::CastOps opcode =
   2510     (SrcBits == DstBits ? Instruction::BitCast :
   2511      (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt));
   2512   return Create(opcode, C, Ty, Name, InsertAtEnd);
   2513 }
   2514 
   2515 // Check whether it is valid to call getCastOpcode for these types.
   2516 // This routine must be kept in sync with getCastOpcode.
   2517 bool CastInst::isCastable(Type *SrcTy, Type *DestTy) {
   2518   if (!SrcTy->isFirstClassType() || !DestTy->isFirstClassType())
   2519     return false;
   2520 
   2521   if (SrcTy == DestTy)
   2522     return true;
   2523 
   2524   if (VectorType *SrcVecTy = dyn_cast<VectorType>(SrcTy))
   2525     if (VectorType *DestVecTy = dyn_cast<VectorType>(DestTy))
   2526       if (SrcVecTy->getNumElements() == DestVecTy->getNumElements()) {
   2527         // An element by element cast.  Valid if casting the elements is valid.
   2528         SrcTy = SrcVecTy->getElementType();
   2529         DestTy = DestVecTy->getElementType();
   2530       }
   2531 
   2532   // Get the bit sizes, we'll need these
   2533   unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();   // 0 for ptr
   2534   unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr
   2535 
   2536   // Run through the possibilities ...
   2537   if (DestTy->isIntegerTy()) {               // Casting to integral
   2538     if (SrcTy->isIntegerTy())                // Casting from integral
   2539         return true;
   2540     if (SrcTy->isFloatingPointTy())   // Casting from floating pt
   2541       return true;
   2542     if (SrcTy->isVectorTy())          // Casting from vector
   2543       return DestBits == SrcBits;
   2544                                       // Casting from something else
   2545     return SrcTy->isPointerTy();
   2546   }
   2547   if (DestTy->isFloatingPointTy()) {  // Casting to floating pt
   2548     if (SrcTy->isIntegerTy())                // Casting from integral
   2549       return true;
   2550     if (SrcTy->isFloatingPointTy())   // Casting from floating pt
   2551       return true;
   2552     if (SrcTy->isVectorTy())          // Casting from vector
   2553       return DestBits == SrcBits;
   2554                                     // Casting from something else
   2555     return false;
   2556   }
   2557   if (DestTy->isVectorTy())         // Casting to vector
   2558     return DestBits == SrcBits;
   2559   if (DestTy->isPointerTy()) {        // Casting to pointer
   2560     if (SrcTy->isPointerTy())                // Casting from pointer
   2561       return true;
   2562     return SrcTy->isIntegerTy();             // Casting from integral
   2563   }
   2564   if (DestTy->isX86_MMXTy()) {
   2565     if (SrcTy->isVectorTy())
   2566       return DestBits == SrcBits;       // 64-bit vector to MMX
   2567     return false;
   2568   }                                    // Casting to something else
   2569   return false;
   2570 }
   2571 
   2572 bool CastInst::isBitCastable(Type *SrcTy, Type *DestTy) {
   2573   if (!SrcTy->isFirstClassType() || !DestTy->isFirstClassType())
   2574     return false;
   2575 
   2576   if (SrcTy == DestTy)
   2577     return true;
   2578 
   2579   if (VectorType *SrcVecTy = dyn_cast<VectorType>(SrcTy)) {
   2580     if (VectorType *DestVecTy = dyn_cast<VectorType>(DestTy)) {
   2581       if (SrcVecTy->getNumElements() == DestVecTy->getNumElements()) {
   2582         // An element by element cast. Valid if casting the elements is valid.
   2583         SrcTy = SrcVecTy->getElementType();
   2584         DestTy = DestVecTy->getElementType();
   2585       }
   2586     }
   2587   }
   2588 
   2589   if (PointerType *DestPtrTy = dyn_cast<PointerType>(DestTy)) {
   2590     if (PointerType *SrcPtrTy = dyn_cast<PointerType>(SrcTy)) {
   2591       return SrcPtrTy->getAddressSpace() == DestPtrTy->getAddressSpace();
   2592     }
   2593   }
   2594 
   2595   unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();   // 0 for ptr
   2596   unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr
   2597 
   2598   // Could still have vectors of pointers if the number of elements doesn't
   2599   // match
   2600   if (SrcBits == 0 || DestBits == 0)
   2601     return false;
   2602 
   2603   if (SrcBits != DestBits)
   2604     return false;
   2605 
   2606   if (DestTy->isX86_MMXTy() || SrcTy->isX86_MMXTy())
   2607     return false;
   2608 
   2609   return true;
   2610 }
   2611 
   2612 bool CastInst::isBitOrNoopPointerCastable(Type *SrcTy, Type *DestTy,
   2613                                           const DataLayout &DL) {
   2614   if (auto *PtrTy = dyn_cast<PointerType>(SrcTy))
   2615     if (auto *IntTy = dyn_cast<IntegerType>(DestTy))
   2616       return IntTy->getBitWidth() == DL.getPointerTypeSizeInBits(PtrTy);
   2617   if (auto *PtrTy = dyn_cast<PointerType>(DestTy))
   2618     if (auto *IntTy = dyn_cast<IntegerType>(SrcTy))
   2619       return IntTy->getBitWidth() == DL.getPointerTypeSizeInBits(PtrTy);
   2620 
   2621   return isBitCastable(SrcTy, DestTy);
   2622 }
   2623 
   2624 // Provide a way to get a "cast" where the cast opcode is inferred from the
   2625 // types and size of the operand. This, basically, is a parallel of the
   2626 // logic in the castIsValid function below.  This axiom should hold:
   2627 //   castIsValid( getCastOpcode(Val, Ty), Val, Ty)
   2628 // should not assert in castIsValid. In other words, this produces a "correct"
   2629 // casting opcode for the arguments passed to it.
   2630 // This routine must be kept in sync with isCastable.
   2631 Instruction::CastOps
   2632 CastInst::getCastOpcode(
   2633   const Value *Src, bool SrcIsSigned, Type *DestTy, bool DestIsSigned) {
   2634   Type *SrcTy = Src->getType();
   2635 
   2636   assert(SrcTy->isFirstClassType() && DestTy->isFirstClassType() &&
   2637          "Only first class types are castable!");
   2638 
   2639   if (SrcTy == DestTy)
   2640     return BitCast;
   2641 
   2642   // FIXME: Check address space sizes here
   2643   if (VectorType *SrcVecTy = dyn_cast<VectorType>(SrcTy))
   2644     if (VectorType *DestVecTy = dyn_cast<VectorType>(DestTy))
   2645       if (SrcVecTy->getNumElements() == DestVecTy->getNumElements()) {
   2646         // An element by element cast.  Find the appropriate opcode based on the
   2647         // element types.
   2648         SrcTy = SrcVecTy->getElementType();
   2649         DestTy = DestVecTy->getElementType();
   2650       }
   2651 
   2652   // Get the bit sizes, we'll need these
   2653   unsigned SrcBits = SrcTy->getPrimitiveSizeInBits();   // 0 for ptr
   2654   unsigned DestBits = DestTy->getPrimitiveSizeInBits(); // 0 for ptr
   2655 
   2656   // Run through the possibilities ...
   2657   if (DestTy->isIntegerTy()) {                      // Casting to integral
   2658     if (SrcTy->isIntegerTy()) {                     // Casting from integral
   2659       if (DestBits < SrcBits)
   2660         return Trunc;                               // int -> smaller int
   2661       else if (DestBits > SrcBits) {                // its an extension
   2662         if (SrcIsSigned)
   2663           return SExt;                              // signed -> SEXT
   2664         else
   2665           return ZExt;                              // unsigned -> ZEXT
   2666       } else {
   2667         return BitCast;                             // Same size, No-op cast
   2668       }
   2669     } else if (SrcTy->isFloatingPointTy()) {        // Casting from floating pt
   2670       if (DestIsSigned)
   2671         return FPToSI;                              // FP -> sint
   2672       else
   2673         return FPToUI;                              // FP -> uint
   2674     } else if (SrcTy->isVectorTy()) {
   2675       assert(DestBits == SrcBits &&
   2676              "Casting vector to integer of different width");
   2677       return BitCast;                             // Same size, no-op cast
   2678     } else {
   2679       assert(SrcTy->isPointerTy() &&
   2680              "Casting from a value that is not first-class type");
   2681       return PtrToInt;                              // ptr -> int
   2682     }
   2683   } else if (DestTy->isFloatingPointTy()) {         // Casting to floating pt
   2684     if (SrcTy->isIntegerTy()) {                     // Casting from integral
   2685       if (SrcIsSigned)
   2686         return SIToFP;                              // sint -> FP
   2687       else
   2688         return UIToFP;                              // uint -> FP
   2689     } else if (SrcTy->isFloatingPointTy()) {        // Casting from floating pt
   2690       if (DestBits < SrcBits) {
   2691         return FPTrunc;                             // FP -> smaller FP
   2692       } else if (DestBits > SrcBits) {
   2693         return FPExt;                               // FP -> larger FP
   2694       } else  {
   2695         return BitCast;                             // same size, no-op cast
   2696       }
   2697     } else if (SrcTy->isVectorTy()) {
   2698       assert(DestBits == SrcBits &&
   2699              "Casting vector to floating point of different width");
   2700       return BitCast;                             // same size, no-op cast
   2701     }
   2702     llvm_unreachable("Casting pointer or non-first class to float");
   2703   } else if (DestTy->isVectorTy()) {
   2704     assert(DestBits == SrcBits &&
   2705            "Illegal cast to vector (wrong type or size)");
   2706     return BitCast;
   2707   } else if (DestTy->isPointerTy()) {
   2708     if (SrcTy->isPointerTy()) {
   2709       if (DestTy->getPointerAddressSpace() != SrcTy->getPointerAddressSpace())
   2710         return AddrSpaceCast;
   2711       return BitCast;                               // ptr -> ptr
   2712     } else if (SrcTy->isIntegerTy()) {
   2713       return IntToPtr;                              // int -> ptr
   2714     }
   2715     llvm_unreachable("Casting pointer to other than pointer or int");
   2716   } else if (DestTy->isX86_MMXTy()) {
   2717     if (SrcTy->isVectorTy()) {
   2718       assert(DestBits == SrcBits && "Casting vector of wrong width to X86_MMX");
   2719       return BitCast;                               // 64-bit vector to MMX
   2720     }
   2721     llvm_unreachable("Illegal cast to X86_MMX");
   2722   }
   2723   llvm_unreachable("Casting to type that is not first-class");
   2724 }
   2725 
   2726 //===----------------------------------------------------------------------===//
   2727 //                    CastInst SubClass Constructors
   2728 //===----------------------------------------------------------------------===//
   2729 
   2730 /// Check that the construction parameters for a CastInst are correct. This
   2731 /// could be broken out into the separate constructors but it is useful to have
   2732 /// it in one place and to eliminate the redundant code for getting the sizes
   2733 /// of the types involved.
   2734 bool
   2735 CastInst::castIsValid(Instruction::CastOps op, Value *S, Type *DstTy) {
   2736 
   2737   // Check for type sanity on the arguments
   2738   Type *SrcTy = S->getType();
   2739 
   2740   if (!SrcTy->isFirstClassType() || !DstTy->isFirstClassType() ||
   2741       SrcTy->isAggregateType() || DstTy->isAggregateType())
   2742     return false;
   2743 
   2744   // Get the size of the types in bits, we'll need this later
   2745   unsigned SrcBitSize = SrcTy->getScalarSizeInBits();
   2746   unsigned DstBitSize = DstTy->getScalarSizeInBits();
   2747 
   2748   // If these are vector types, get the lengths of the vectors (using zero for
   2749   // scalar types means that checking that vector lengths match also checks that
   2750   // scalars are not being converted to vectors or vectors to scalars).
   2751   unsigned SrcLength = SrcTy->isVectorTy() ?
   2752     cast<VectorType>(SrcTy)->getNumElements() : 0;
   2753   unsigned DstLength = DstTy->isVectorTy() ?
   2754     cast<VectorType>(DstTy)->getNumElements() : 0;
   2755 
   2756   // Switch on the opcode provided
   2757   switch (op) {
   2758   default: return false; // This is an input error
   2759   case Instruction::Trunc:
   2760     return SrcTy->isIntOrIntVectorTy() && DstTy->isIntOrIntVectorTy() &&
   2761       SrcLength == DstLength && SrcBitSize > DstBitSize;
   2762   case Instruction::ZExt:
   2763     return SrcTy->isIntOrIntVectorTy() && DstTy->isIntOrIntVectorTy() &&
   2764       SrcLength == DstLength && SrcBitSize < DstBitSize;
   2765   case Instruction::SExt:
   2766     return SrcTy->isIntOrIntVectorTy() && DstTy->isIntOrIntVectorTy() &&
   2767       SrcLength == DstLength && SrcBitSize < DstBitSize;
   2768   case Instruction::FPTrunc:
   2769     return SrcTy->isFPOrFPVectorTy() && DstTy->isFPOrFPVectorTy() &&
   2770       SrcLength == DstLength && SrcBitSize > DstBitSize;
   2771   case Instruction::FPExt:
   2772     return SrcTy->isFPOrFPVectorTy() && DstTy->isFPOrFPVectorTy() &&
   2773       SrcLength == DstLength && SrcBitSize < DstBitSize;
   2774   case Instruction::UIToFP:
   2775   case Instruction::SIToFP:
   2776     return SrcTy->isIntOrIntVectorTy() && DstTy->isFPOrFPVectorTy() &&
   2777       SrcLength == DstLength;
   2778   case Instruction::FPToUI:
   2779   case Instruction::FPToSI:
   2780     return SrcTy->isFPOrFPVectorTy() && DstTy->isIntOrIntVectorTy() &&
   2781       SrcLength == DstLength;
   2782   case Instruction::PtrToInt:
   2783     if (isa<VectorType>(SrcTy) != isa<VectorType>(DstTy))
   2784       return false;
   2785     if (VectorType *VT = dyn_cast<VectorType>(SrcTy))
   2786       if (VT->getNumElements() != cast<VectorType>(DstTy)->getNumElements())
   2787         return false;
   2788     return SrcTy->getScalarType()->isPointerTy() &&
   2789            DstTy->getScalarType()->isIntegerTy();
   2790   case Instruction::IntToPtr:
   2791     if (isa<VectorType>(SrcTy) != isa<VectorType>(DstTy))
   2792       return false;
   2793     if (VectorType *VT = dyn_cast<VectorType>(SrcTy))
   2794       if (VT->getNumElements() != cast<VectorType>(DstTy)->getNumElements())
   2795         return false;
   2796     return SrcTy->getScalarType()->isIntegerTy() &&
   2797            DstTy->getScalarType()->isPointerTy();
   2798   case Instruction::BitCast: {
   2799     PointerType *SrcPtrTy = dyn_cast<PointerType>(SrcTy->getScalarType());
   2800     PointerType *DstPtrTy = dyn_cast<PointerType>(DstTy->getScalarType());
   2801 
   2802     // BitCast implies a no-op cast of type only. No bits change.
   2803     // However, you can't cast pointers to anything but pointers.
   2804     if (!SrcPtrTy != !DstPtrTy)
   2805       return false;
   2806 
   2807     // For non-pointer cases, the cast is okay if the source and destination bit
   2808     // widths are identical.
   2809     if (!SrcPtrTy)
   2810       return SrcTy->getPrimitiveSizeInBits() == DstTy->getPrimitiveSizeInBits();
   2811 
   2812     // If both are pointers then the address spaces must match.
   2813     if (SrcPtrTy->getAddressSpace() != DstPtrTy->getAddressSpace())
   2814       return false;
   2815 
   2816     // A vector of pointers must have the same number of elements.
   2817     if (VectorType *SrcVecTy = dyn_cast<VectorType>(SrcTy)) {
   2818       if (VectorType *DstVecTy = dyn_cast<VectorType>(DstTy))
   2819         return (SrcVecTy->getNumElements() == DstVecTy->getNumElements());
   2820 
   2821       return false;
   2822     }
   2823 
   2824     return true;
   2825   }
   2826   case Instruction::AddrSpaceCast: {
   2827     PointerType *SrcPtrTy = dyn_cast<PointerType>(SrcTy->getScalarType());
   2828     if (!SrcPtrTy)
   2829       return false;
   2830 
   2831     PointerType *DstPtrTy = dyn_cast<PointerType>(DstTy->getScalarType());
   2832     if (!DstPtrTy)
   2833       return false;
   2834 
   2835     if (SrcPtrTy->getAddressSpace() == DstPtrTy->getAddressSpace())
   2836       return false;
   2837 
   2838     if (VectorType *SrcVecTy = dyn_cast<VectorType>(SrcTy)) {
   2839       if (VectorType *DstVecTy = dyn_cast<VectorType>(DstTy))
   2840         return (SrcVecTy->getNumElements() == DstVecTy->getNumElements());
   2841 
   2842       return false;
   2843     }
   2844 
   2845     return true;
   2846   }
   2847   }
   2848 }
   2849 
   2850 TruncInst::TruncInst(
   2851   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2852 ) : CastInst(Ty, Trunc, S, Name, InsertBefore) {
   2853   assert(castIsValid(getOpcode(), S, Ty) && "Illegal Trunc");
   2854 }
   2855 
   2856 TruncInst::TruncInst(
   2857   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2858 ) : CastInst(Ty, Trunc, S, Name, InsertAtEnd) {
   2859   assert(castIsValid(getOpcode(), S, Ty) && "Illegal Trunc");
   2860 }
   2861 
   2862 ZExtInst::ZExtInst(
   2863   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2864 )  : CastInst(Ty, ZExt, S, Name, InsertBefore) {
   2865   assert(castIsValid(getOpcode(), S, Ty) && "Illegal ZExt");
   2866 }
   2867 
   2868 ZExtInst::ZExtInst(
   2869   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2870 )  : CastInst(Ty, ZExt, S, Name, InsertAtEnd) {
   2871   assert(castIsValid(getOpcode(), S, Ty) && "Illegal ZExt");
   2872 }
   2873 SExtInst::SExtInst(
   2874   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2875 ) : CastInst(Ty, SExt, S, Name, InsertBefore) {
   2876   assert(castIsValid(getOpcode(), S, Ty) && "Illegal SExt");
   2877 }
   2878 
   2879 SExtInst::SExtInst(
   2880   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2881 )  : CastInst(Ty, SExt, S, Name, InsertAtEnd) {
   2882   assert(castIsValid(getOpcode(), S, Ty) && "Illegal SExt");
   2883 }
   2884 
   2885 FPTruncInst::FPTruncInst(
   2886   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2887 ) : CastInst(Ty, FPTrunc, S, Name, InsertBefore) {
   2888   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPTrunc");
   2889 }
   2890 
   2891 FPTruncInst::FPTruncInst(
   2892   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2893 ) : CastInst(Ty, FPTrunc, S, Name, InsertAtEnd) {
   2894   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPTrunc");
   2895 }
   2896 
   2897 FPExtInst::FPExtInst(
   2898   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2899 ) : CastInst(Ty, FPExt, S, Name, InsertBefore) {
   2900   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPExt");
   2901 }
   2902 
   2903 FPExtInst::FPExtInst(
   2904   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2905 ) : CastInst(Ty, FPExt, S, Name, InsertAtEnd) {
   2906   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPExt");
   2907 }
   2908 
   2909 UIToFPInst::UIToFPInst(
   2910   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2911 ) : CastInst(Ty, UIToFP, S, Name, InsertBefore) {
   2912   assert(castIsValid(getOpcode(), S, Ty) && "Illegal UIToFP");
   2913 }
   2914 
   2915 UIToFPInst::UIToFPInst(
   2916   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2917 ) : CastInst(Ty, UIToFP, S, Name, InsertAtEnd) {
   2918   assert(castIsValid(getOpcode(), S, Ty) && "Illegal UIToFP");
   2919 }
   2920 
   2921 SIToFPInst::SIToFPInst(
   2922   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2923 ) : CastInst(Ty, SIToFP, S, Name, InsertBefore) {
   2924   assert(castIsValid(getOpcode(), S, Ty) && "Illegal SIToFP");
   2925 }
   2926 
   2927 SIToFPInst::SIToFPInst(
   2928   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2929 ) : CastInst(Ty, SIToFP, S, Name, InsertAtEnd) {
   2930   assert(castIsValid(getOpcode(), S, Ty) && "Illegal SIToFP");
   2931 }
   2932 
   2933 FPToUIInst::FPToUIInst(
   2934   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2935 ) : CastInst(Ty, FPToUI, S, Name, InsertBefore) {
   2936   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPToUI");
   2937 }
   2938 
   2939 FPToUIInst::FPToUIInst(
   2940   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2941 ) : CastInst(Ty, FPToUI, S, Name, InsertAtEnd) {
   2942   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPToUI");
   2943 }
   2944 
   2945 FPToSIInst::FPToSIInst(
   2946   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2947 ) : CastInst(Ty, FPToSI, S, Name, InsertBefore) {
   2948   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPToSI");
   2949 }
   2950 
   2951 FPToSIInst::FPToSIInst(
   2952   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2953 ) : CastInst(Ty, FPToSI, S, Name, InsertAtEnd) {
   2954   assert(castIsValid(getOpcode(), S, Ty) && "Illegal FPToSI");
   2955 }
   2956 
   2957 PtrToIntInst::PtrToIntInst(
   2958   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2959 ) : CastInst(Ty, PtrToInt, S, Name, InsertBefore) {
   2960   assert(castIsValid(getOpcode(), S, Ty) && "Illegal PtrToInt");
   2961 }
   2962 
   2963 PtrToIntInst::PtrToIntInst(
   2964   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2965 ) : CastInst(Ty, PtrToInt, S, Name, InsertAtEnd) {
   2966   assert(castIsValid(getOpcode(), S, Ty) && "Illegal PtrToInt");
   2967 }
   2968 
   2969 IntToPtrInst::IntToPtrInst(
   2970   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2971 ) : CastInst(Ty, IntToPtr, S, Name, InsertBefore) {
   2972   assert(castIsValid(getOpcode(), S, Ty) && "Illegal IntToPtr");
   2973 }
   2974 
   2975 IntToPtrInst::IntToPtrInst(
   2976   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2977 ) : CastInst(Ty, IntToPtr, S, Name, InsertAtEnd) {
   2978   assert(castIsValid(getOpcode(), S, Ty) && "Illegal IntToPtr");
   2979 }
   2980 
   2981 BitCastInst::BitCastInst(
   2982   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2983 ) : CastInst(Ty, BitCast, S, Name, InsertBefore) {
   2984   assert(castIsValid(getOpcode(), S, Ty) && "Illegal BitCast");
   2985 }
   2986 
   2987 BitCastInst::BitCastInst(
   2988   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   2989 ) : CastInst(Ty, BitCast, S, Name, InsertAtEnd) {
   2990   assert(castIsValid(getOpcode(), S, Ty) && "Illegal BitCast");
   2991 }
   2992 
   2993 AddrSpaceCastInst::AddrSpaceCastInst(
   2994   Value *S, Type *Ty, const Twine &Name, Instruction *InsertBefore
   2995 ) : CastInst(Ty, AddrSpaceCast, S, Name, InsertBefore) {
   2996   assert(castIsValid(getOpcode(), S, Ty) && "Illegal AddrSpaceCast");
   2997 }
   2998 
   2999 AddrSpaceCastInst::AddrSpaceCastInst(
   3000   Value *S, Type *Ty, const Twine &Name, BasicBlock *InsertAtEnd
   3001 ) : CastInst(Ty, AddrSpaceCast, S, Name, InsertAtEnd) {
   3002   assert(castIsValid(getOpcode(), S, Ty) && "Illegal AddrSpaceCast");
   3003 }
   3004 
   3005 //===----------------------------------------------------------------------===//
   3006 //                               CmpInst Classes
   3007 //===----------------------------------------------------------------------===//
   3008 
   3009 void CmpInst::anchor() {}
   3010 
   3011 CmpInst::CmpInst(Type *ty, OtherOps op, unsigned short predicate,
   3012                  Value *LHS, Value *RHS, const Twine &Name,
   3013                  Instruction *InsertBefore)
   3014   : Instruction(ty, op,
   3015                 OperandTraits<CmpInst>::op_begin(this),
   3016                 OperandTraits<CmpInst>::operands(this),
   3017                 InsertBefore) {
   3018     Op<0>() = LHS;
   3019     Op<1>() = RHS;
   3020   setPredicate((Predicate)predicate);
   3021   setName(Name);
   3022 }
   3023 
   3024 CmpInst::CmpInst(Type *ty, OtherOps op, unsigned short predicate,
   3025                  Value *LHS, Value *RHS, const Twine &Name,
   3026                  BasicBlock *InsertAtEnd)
   3027   : Instruction(ty, op,
   3028                 OperandTraits<CmpInst>::op_begin(this),
   3029                 OperandTraits<CmpInst>::operands(this),
   3030                 InsertAtEnd) {
   3031   Op<0>() = LHS;
   3032   Op<1>() = RHS;
   3033   setPredicate((Predicate)predicate);
   3034   setName(Name);
   3035 }
   3036 
   3037 CmpInst *
   3038 CmpInst::Create(OtherOps Op, unsigned short predicate,
   3039                 Value *S1, Value *S2,
   3040                 const Twine &Name, Instruction *InsertBefore) {
   3041   if (Op == Instruction::ICmp) {
   3042     if (InsertBefore)
   3043       return new ICmpInst(InsertBefore, CmpInst::Predicate(predicate),
   3044                           S1, S2, Name);
   3045     else
   3046       return new ICmpInst(CmpInst::Predicate(predicate),
   3047                           S1, S2, Name);
   3048   }
   3049 
   3050   if (InsertBefore)
   3051     return new FCmpInst(InsertBefore, CmpInst::Predicate(predicate),
   3052                         S1, S2, Name);
   3053   else
   3054     return new FCmpInst(CmpInst::Predicate(predicate),
   3055                         S1, S2, Name);
   3056 }
   3057 
   3058 CmpInst *
   3059 CmpInst::Create(OtherOps Op, unsigned short predicate, Value *S1, Value *S2,
   3060                 const Twine &Name, BasicBlock *InsertAtEnd) {
   3061   if (Op == Instruction::ICmp) {
   3062     return new ICmpInst(*InsertAtEnd, CmpInst::Predicate(predicate),
   3063                         S1, S2, Name);
   3064   }
   3065   return new FCmpInst(*InsertAtEnd, CmpInst::Predicate(predicate),
   3066                       S1, S2, Name);
   3067 }
   3068 
   3069 void CmpInst::swapOperands() {
   3070   if (ICmpInst *IC = dyn_cast<ICmpInst>(this))
   3071     IC->swapOperands();
   3072   else
   3073     cast<FCmpInst>(this)->swapOperands();
   3074 }
   3075 
   3076 bool CmpInst::isCommutative() const {
   3077   if (const ICmpInst *IC = dyn_cast<ICmpInst>(this))
   3078     return IC->isCommutative();
   3079   return cast<FCmpInst>(this)->isCommutative();
   3080 }
   3081 
   3082 bool CmpInst::isEquality() const {
   3083   if (const ICmpInst *IC = dyn_cast<ICmpInst>(this))
   3084     return IC->isEquality();
   3085   return cast<FCmpInst>(this)->isEquality();
   3086 }
   3087 
   3088 
   3089 CmpInst::Predicate CmpInst::getInversePredicate(Predicate pred) {
   3090   switch (pred) {
   3091     default: llvm_unreachable("Unknown cmp predicate!");
   3092     case ICMP_EQ: return ICMP_NE;
   3093     case ICMP_NE: return ICMP_EQ;
   3094     case ICMP_UGT: return ICMP_ULE;
   3095     case ICMP_ULT: return ICMP_UGE;
   3096     case ICMP_UGE: return ICMP_ULT;
   3097     case ICMP_ULE: return ICMP_UGT;
   3098     case ICMP_SGT: return ICMP_SLE;
   3099     case ICMP_SLT: return ICMP_SGE;
   3100     case ICMP_SGE: return ICMP_SLT;
   3101     case ICMP_SLE: return ICMP_SGT;
   3102 
   3103     case FCMP_OEQ: return FCMP_UNE;
   3104     case FCMP_ONE: return FCMP_UEQ;
   3105     case FCMP_OGT: return FCMP_ULE;
   3106     case FCMP_OLT: return FCMP_UGE;
   3107     case FCMP_OGE: return FCMP_ULT;
   3108     case FCMP_OLE: return FCMP_UGT;
   3109     case FCMP_UEQ: return FCMP_ONE;
   3110     case FCMP_UNE: return FCMP_OEQ;
   3111     case FCMP_UGT: return FCMP_OLE;
   3112     case FCMP_ULT: return FCMP_OGE;
   3113     case FCMP_UGE: return FCMP_OLT;
   3114     case FCMP_ULE: return FCMP_OGT;
   3115     case FCMP_ORD: return FCMP_UNO;
   3116     case FCMP_UNO: return FCMP_ORD;
   3117     case FCMP_TRUE: return FCMP_FALSE;
   3118     case FCMP_FALSE: return FCMP_TRUE;
   3119   }
   3120 }
   3121 
   3122 ICmpInst::Predicate ICmpInst::getSignedPredicate(Predicate pred) {
   3123   switch (pred) {
   3124     default: llvm_unreachable("Unknown icmp predicate!");
   3125     case ICMP_EQ: case ICMP_NE:
   3126     case ICMP_SGT: case ICMP_SLT: case ICMP_SGE: case ICMP_SLE:
   3127        return pred;
   3128     case ICMP_UGT: return ICMP_SGT;
   3129     case ICMP_ULT: return ICMP_SLT;
   3130     case ICMP_UGE: return ICMP_SGE;
   3131     case ICMP_ULE: return ICMP_SLE;
   3132   }
   3133 }
   3134 
   3135 ICmpInst::Predicate ICmpInst::getUnsignedPredicate(Predicate pred) {
   3136   switch (pred) {
   3137     default: llvm_unreachable("Unknown icmp predicate!");
   3138     case ICMP_EQ: case ICMP_NE:
   3139     case ICMP_UGT: case ICMP_ULT: case ICMP_UGE: case ICMP_ULE:
   3140        return pred;
   3141     case ICMP_SGT: return ICMP_UGT;
   3142     case ICMP_SLT: return ICMP_ULT;
   3143     case ICMP_SGE: return ICMP_UGE;
   3144     case ICMP_SLE: return ICMP_ULE;
   3145   }
   3146 }
   3147 
   3148 /// Initialize a set of values that all satisfy the condition with C.
   3149 ///
   3150 ConstantRange
   3151 ICmpInst::makeConstantRange(Predicate pred, const APInt &C) {
   3152   APInt Lower(C);
   3153   APInt Upper(C);
   3154   uint32_t BitWidth = C.getBitWidth();
   3155   switch (pred) {
   3156   default: llvm_unreachable("Invalid ICmp opcode to ConstantRange ctor!");
   3157   case ICmpInst::ICMP_EQ: ++Upper; break;
   3158   case ICmpInst::ICMP_NE: ++Lower; break;
   3159   case ICmpInst::ICMP_ULT:
   3160     Lower = APInt::getMinValue(BitWidth);
   3161     // Check for an empty-set condition.
   3162     if (Lower == Upper)
   3163       return ConstantRange(BitWidth, /*isFullSet=*/false);
   3164     break;
   3165   case ICmpInst::ICMP_SLT:
   3166     Lower = APInt::getSignedMinValue(BitWidth);
   3167     // Check for an empty-set condition.
   3168     if (Lower == Upper)
   3169       return ConstantRange(BitWidth, /*isFullSet=*/false);
   3170     break;
   3171   case ICmpInst::ICMP_UGT:
   3172     ++Lower; Upper = APInt::getMinValue(BitWidth);        // Min = Next(Max)
   3173     // Check for an empty-set condition.
   3174     if (Lower == Upper)
   3175       return ConstantRange(BitWidth, /*isFullSet=*/false);
   3176     break;
   3177   case ICmpInst::ICMP_SGT:
   3178     ++Lower; Upper = APInt::getSignedMinValue(BitWidth);  // Min = Next(Max)
   3179     // Check for an empty-set condition.
   3180     if (Lower == Upper)
   3181       return ConstantRange(BitWidth, /*isFullSet=*/false);
   3182     break;
   3183   case ICmpInst::ICMP_ULE:
   3184     Lower = APInt::getMinValue(BitWidth); ++Upper;
   3185     // Check for a full-set condition.
   3186     if (Lower == Upper)
   3187       return ConstantRange(BitWidth, /*isFullSet=*/true);
   3188     break;
   3189   case ICmpInst::ICMP_SLE:
   3190     Lower = APInt::getSignedMinValue(BitWidth); ++Upper;
   3191     // Check for a full-set condition.
   3192     if (Lower == Upper)
   3193       return ConstantRange(BitWidth, /*isFullSet=*/true);
   3194     break;
   3195   case ICmpInst::ICMP_UGE:
   3196     Upper = APInt::getMinValue(BitWidth);        // Min = Next(Max)
   3197     // Check for a full-set condition.
   3198     if (Lower == Upper)
   3199       return ConstantRange(BitWidth, /*isFullSet=*/true);
   3200     break;
   3201   case ICmpInst::ICMP_SGE:
   3202     Upper = APInt::getSignedMinValue(BitWidth);  // Min = Next(Max)
   3203     // Check for a full-set condition.
   3204     if (Lower == Upper)
   3205       return ConstantRange(BitWidth, /*isFullSet=*/true);
   3206     break;
   3207   }
   3208   return ConstantRange(Lower, Upper);
   3209 }
   3210 
   3211 CmpInst::Predicate CmpInst::getSwappedPredicate(Predicate pred) {
   3212   switch (pred) {
   3213     default: llvm_unreachable("Unknown cmp predicate!");
   3214     case ICMP_EQ: case ICMP_NE:
   3215       return pred;
   3216     case ICMP_SGT: return ICMP_SLT;
   3217     case ICMP_SLT: return ICMP_SGT;
   3218     case ICMP_SGE: return ICMP_SLE;
   3219     case ICMP_SLE: return ICMP_SGE;
   3220     case ICMP_UGT: return ICMP_ULT;
   3221     case ICMP_ULT: return ICMP_UGT;
   3222     case ICMP_UGE: return ICMP_ULE;
   3223     case ICMP_ULE: return ICMP_UGE;
   3224 
   3225     case FCMP_FALSE: case FCMP_TRUE:
   3226     case FCMP_OEQ: case FCMP_ONE:
   3227     case FCMP_UEQ: case FCMP_UNE:
   3228     case FCMP_ORD: case FCMP_UNO:
   3229       return pred;
   3230     case FCMP_OGT: return FCMP_OLT;
   3231     case FCMP_OLT: return FCMP_OGT;
   3232     case FCMP_OGE: return FCMP_OLE;
   3233     case FCMP_OLE: return FCMP_OGE;
   3234     case FCMP_UGT: return FCMP_ULT;
   3235     case FCMP_ULT: return FCMP_UGT;
   3236     case FCMP_UGE: return FCMP_ULE;
   3237     case FCMP_ULE: return FCMP_UGE;
   3238   }
   3239 }
   3240 
   3241 bool CmpInst::isUnsigned(unsigned short predicate) {
   3242   switch (predicate) {
   3243     default: return false;
   3244     case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_ULE: case ICmpInst::ICMP_UGT:
   3245     case ICmpInst::ICMP_UGE: return true;
   3246   }
   3247 }
   3248 
   3249 bool CmpInst::isSigned(unsigned short predicate) {
   3250   switch (predicate) {
   3251     default: return false;
   3252     case ICmpInst::ICMP_SLT: case ICmpInst::ICMP_SLE: case ICmpInst::ICMP_SGT:
   3253     case ICmpInst::ICMP_SGE: return true;
   3254   }
   3255 }
   3256 
   3257 bool CmpInst::isOrdered(unsigned short predicate) {
   3258   switch (predicate) {
   3259     default: return false;
   3260     case FCmpInst::FCMP_OEQ: case FCmpInst::FCMP_ONE: case FCmpInst::FCMP_OGT:
   3261     case FCmpInst::FCMP_OLT: case FCmpInst::FCMP_OGE: case FCmpInst::FCMP_OLE:
   3262     case FCmpInst::FCMP_ORD: return true;
   3263   }
   3264 }
   3265 
   3266 bool CmpInst::isUnordered(unsigned short predicate) {
   3267   switch (predicate) {
   3268     default: return false;
   3269     case FCmpInst::FCMP_UEQ: case FCmpInst::FCMP_UNE: case FCmpInst::FCMP_UGT:
   3270     case FCmpInst::FCMP_ULT: case FCmpInst::FCMP_UGE: case FCmpInst::FCMP_ULE:
   3271     case FCmpInst::FCMP_UNO: return true;
   3272   }
   3273 }
   3274 
   3275 bool CmpInst::isTrueWhenEqual(unsigned short predicate) {
   3276   switch(predicate) {
   3277     default: return false;
   3278     case ICMP_EQ:   case ICMP_UGE: case ICMP_ULE: case ICMP_SGE: case ICMP_SLE:
   3279     case FCMP_TRUE: case FCMP_UEQ: case FCMP_UGE: case FCMP_ULE: return true;
   3280   }
   3281 }
   3282 
   3283 bool CmpInst::isFalseWhenEqual(unsigned short predicate) {
   3284   switch(predicate) {
   3285   case ICMP_NE:    case ICMP_UGT: case ICMP_ULT: case ICMP_SGT: case ICMP_SLT:
   3286   case FCMP_FALSE: case FCMP_ONE: case FCMP_OGT: case FCMP_OLT: return true;
   3287   default: return false;
   3288   }
   3289 }
   3290 
   3291 
   3292 //===----------------------------------------------------------------------===//
   3293 //                        SwitchInst Implementation
   3294 //===----------------------------------------------------------------------===//
   3295 
   3296 void SwitchInst::init(Value *Value, BasicBlock *Default, unsigned NumReserved) {
   3297   assert(Value && Default && NumReserved);
   3298   ReservedSpace = NumReserved;
   3299   NumOperands = 2;
   3300   OperandList = allocHungoffUses(ReservedSpace);
   3301 
   3302   OperandList[0] = Value;
   3303   OperandList[1] = Default;
   3304 }
   3305 
   3306 /// SwitchInst ctor - Create a new switch instruction, specifying a value to
   3307 /// switch on and a default destination.  The number of additional cases can
   3308 /// be specified here to make memory allocation more efficient.  This
   3309 /// constructor can also autoinsert before another instruction.
   3310 SwitchInst::SwitchInst(Value *Value, BasicBlock *Default, unsigned NumCases,
   3311                        Instruction *InsertBefore)
   3312   : TerminatorInst(Type::getVoidTy(Value->getContext()), Instruction::Switch,
   3313                    nullptr, 0, InsertBefore) {
   3314   init(Value, Default, 2+NumCases*2);
   3315 }
   3316 
   3317 /// SwitchInst ctor - Create a new switch instruction, specifying a value to
   3318 /// switch on and a default destination.  The number of additional cases can
   3319 /// be specified here to make memory allocation more efficient.  This
   3320 /// constructor also autoinserts at the end of the specified BasicBlock.
   3321 SwitchInst::SwitchInst(Value *Value, BasicBlock *Default, unsigned NumCases,
   3322                        BasicBlock *InsertAtEnd)
   3323   : TerminatorInst(Type::getVoidTy(Value->getContext()), Instruction::Switch,
   3324                    nullptr, 0, InsertAtEnd) {
   3325   init(Value, Default, 2+NumCases*2);
   3326 }
   3327 
   3328 SwitchInst::SwitchInst(const SwitchInst &SI)
   3329   : TerminatorInst(SI.getType(), Instruction::Switch, nullptr, 0) {
   3330   init(SI.getCondition(), SI.getDefaultDest(), SI.getNumOperands());
   3331   NumOperands = SI.getNumOperands();
   3332   Use *OL = OperandList, *InOL = SI.OperandList;
   3333   for (unsigned i = 2, E = SI.getNumOperands(); i != E; i += 2) {
   3334     OL[i] = InOL[i];
   3335     OL[i+1] = InOL[i+1];
   3336   }
   3337   SubclassOptionalData = SI.SubclassOptionalData;
   3338 }
   3339 
   3340 SwitchInst::~SwitchInst() {
   3341   dropHungoffUses();
   3342 }
   3343 
   3344 
   3345 /// addCase - Add an entry to the switch instruction...
   3346 ///
   3347 void SwitchInst::addCase(ConstantInt *OnVal, BasicBlock *Dest) {
   3348   unsigned NewCaseIdx = getNumCases();
   3349   unsigned OpNo = NumOperands;
   3350   if (OpNo+2 > ReservedSpace)
   3351     growOperands();  // Get more space!
   3352   // Initialize some new operands.
   3353   assert(OpNo+1 < ReservedSpace && "Growing didn't work!");
   3354   NumOperands = OpNo+2;
   3355   CaseIt Case(this, NewCaseIdx);
   3356   Case.setValue(OnVal);
   3357   Case.setSuccessor(Dest);
   3358 }
   3359 
   3360 /// removeCase - This method removes the specified case and its successor
   3361 /// from the switch instruction.
   3362 void SwitchInst::removeCase(CaseIt i) {
   3363   unsigned idx = i.getCaseIndex();
   3364 
   3365   assert(2 + idx*2 < getNumOperands() && "Case index out of range!!!");
   3366 
   3367   unsigned NumOps = getNumOperands();
   3368   Use *OL = OperandList;
   3369 
   3370   // Overwrite this case with the end of the list.
   3371   if (2 + (idx + 1) * 2 != NumOps) {
   3372     OL[2 + idx * 2] = OL[NumOps - 2];
   3373     OL[2 + idx * 2 + 1] = OL[NumOps - 1];
   3374   }
   3375 
   3376   // Nuke the last value.
   3377   OL[NumOps-2].set(nullptr);
   3378   OL[NumOps-2+1].set(nullptr);
   3379   NumOperands = NumOps-2;
   3380 }
   3381 
   3382 /// growOperands - grow operands - This grows the operand list in response
   3383 /// to a push_back style of operation.  This grows the number of ops by 3 times.
   3384 ///
   3385 void SwitchInst::growOperands() {
   3386   unsigned e = getNumOperands();
   3387   unsigned NumOps = e*3;
   3388 
   3389   ReservedSpace = NumOps;
   3390   Use *NewOps = allocHungoffUses(NumOps);
   3391   Use *OldOps = OperandList;
   3392   for (unsigned i = 0; i != e; ++i) {
   3393       NewOps[i] = OldOps[i];
   3394   }
   3395   OperandList = NewOps;
   3396   Use::zap(OldOps, OldOps + e, true);
   3397 }
   3398 
   3399 
   3400 BasicBlock *SwitchInst::getSuccessorV(unsigned idx) const {
   3401   return getSuccessor(idx);
   3402 }
   3403 unsigned SwitchInst::getNumSuccessorsV() const {
   3404   return getNumSuccessors();
   3405 }
   3406 void SwitchInst::setSuccessorV(unsigned idx, BasicBlock *B) {
   3407   setSuccessor(idx, B);
   3408 }
   3409 
   3410 //===----------------------------------------------------------------------===//
   3411 //                        IndirectBrInst Implementation
   3412 //===----------------------------------------------------------------------===//
   3413 
   3414 void IndirectBrInst::init(Value *Address, unsigned NumDests) {
   3415   assert(Address && Address->getType()->isPointerTy() &&
   3416          "Address of indirectbr must be a pointer");
   3417   ReservedSpace = 1+NumDests;
   3418   NumOperands = 1;
   3419   OperandList = allocHungoffUses(ReservedSpace);
   3420 
   3421   OperandList[0] = Address;
   3422 }
   3423 
   3424 
   3425 /// growOperands - grow operands - This grows the operand list in response
   3426 /// to a push_back style of operation.  This grows the number of ops by 2 times.
   3427 ///
   3428 void IndirectBrInst::growOperands() {
   3429   unsigned e = getNumOperands();
   3430   unsigned NumOps = e*2;
   3431 
   3432   ReservedSpace = NumOps;
   3433   Use *NewOps = allocHungoffUses(NumOps);
   3434   Use *OldOps = OperandList;
   3435   for (unsigned i = 0; i != e; ++i)
   3436     NewOps[i] = OldOps[i];
   3437   OperandList = NewOps;
   3438   Use::zap(OldOps, OldOps + e, true);
   3439 }
   3440 
   3441 IndirectBrInst::IndirectBrInst(Value *Address, unsigned NumCases,
   3442                                Instruction *InsertBefore)
   3443 : TerminatorInst(Type::getVoidTy(Address->getContext()),Instruction::IndirectBr,
   3444                  nullptr, 0, InsertBefore) {
   3445   init(Address, NumCases);
   3446 }
   3447 
   3448 IndirectBrInst::IndirectBrInst(Value *Address, unsigned NumCases,
   3449                                BasicBlock *InsertAtEnd)
   3450 : TerminatorInst(Type::getVoidTy(Address->getContext()),Instruction::IndirectBr,
   3451                  nullptr, 0, InsertAtEnd) {
   3452   init(Address, NumCases);
   3453 }
   3454 
   3455 IndirectBrInst::IndirectBrInst(const IndirectBrInst &IBI)
   3456   : TerminatorInst(Type::getVoidTy(IBI.getContext()), Instruction::IndirectBr,
   3457                    allocHungoffUses(IBI.getNumOperands()),
   3458                    IBI.getNumOperands()) {
   3459   Use *OL = OperandList, *InOL = IBI.OperandList;
   3460   for (unsigned i = 0, E = IBI.getNumOperands(); i != E; ++i)
   3461     OL[i] = InOL[i];
   3462   SubclassOptionalData = IBI.SubclassOptionalData;
   3463 }
   3464 
   3465 IndirectBrInst::~IndirectBrInst() {
   3466   dropHungoffUses();
   3467 }
   3468 
   3469 /// addDestination - Add a destination.
   3470 ///
   3471 void IndirectBrInst::addDestination(BasicBlock *DestBB) {
   3472   unsigned OpNo = NumOperands;
   3473   if (OpNo+1 > ReservedSpace)
   3474     growOperands();  // Get more space!
   3475   // Initialize some new operands.
   3476   assert(OpNo < ReservedSpace && "Growing didn't work!");
   3477   NumOperands = OpNo+1;
   3478   OperandList[OpNo] = DestBB;
   3479 }
   3480 
   3481 /// removeDestination - This method removes the specified successor from the
   3482 /// indirectbr instruction.
   3483 void IndirectBrInst::removeDestination(unsigned idx) {
   3484   assert(idx < getNumOperands()-1 && "Successor index out of range!");
   3485 
   3486   unsigned NumOps = getNumOperands();
   3487   Use *OL = OperandList;
   3488 
   3489   // Replace this value with the last one.
   3490   OL[idx+1] = OL[NumOps-1];
   3491 
   3492   // Nuke the last value.
   3493   OL[NumOps-1].set(nullptr);
   3494   NumOperands = NumOps-1;
   3495 }
   3496 
   3497 BasicBlock *IndirectBrInst::getSuccessorV(unsigned idx) const {
   3498   return getSuccessor(idx);
   3499 }
   3500 unsigned IndirectBrInst::getNumSuccessorsV() const {
   3501   return getNumSuccessors();
   3502 }
   3503 void IndirectBrInst::setSuccessorV(unsigned idx, BasicBlock *B) {
   3504   setSuccessor(idx, B);
   3505 }
   3506 
   3507 //===----------------------------------------------------------------------===//
   3508 //                           clone_impl() implementations
   3509 //===----------------------------------------------------------------------===//
   3510 
   3511 // Define these methods here so vtables don't get emitted into every translation
   3512 // unit that uses these classes.
   3513 
   3514 GetElementPtrInst *GetElementPtrInst::clone_impl() const {
   3515   return new (getNumOperands()) GetElementPtrInst(*this);
   3516 }
   3517 
   3518 BinaryOperator *BinaryOperator::clone_impl() const {
   3519   return Create(getOpcode(), Op<0>(), Op<1>());
   3520 }
   3521 
   3522 FCmpInst* FCmpInst::clone_impl() const {
   3523   return new FCmpInst(getPredicate(), Op<0>(), Op<1>());
   3524 }
   3525 
   3526 ICmpInst* ICmpInst::clone_impl() const {
   3527   return new ICmpInst(getPredicate(), Op<0>(), Op<1>());
   3528 }
   3529 
   3530 ExtractValueInst *ExtractValueInst::clone_impl() const {
   3531   return new ExtractValueInst(*this);
   3532 }
   3533 
   3534 InsertValueInst *InsertValueInst::clone_impl() const {
   3535   return new InsertValueInst(*this);
   3536 }
   3537 
   3538 AllocaInst *AllocaInst::clone_impl() const {
   3539   AllocaInst *Result = new AllocaInst(getAllocatedType(),
   3540                                       (Value *)getOperand(0), getAlignment());
   3541   Result->setUsedWithInAlloca(isUsedWithInAlloca());
   3542   return Result;
   3543 }
   3544 
   3545 LoadInst *LoadInst::clone_impl() const {
   3546   return new LoadInst(getOperand(0), Twine(), isVolatile(),
   3547                       getAlignment(), getOrdering(), getSynchScope());
   3548 }
   3549 
   3550 StoreInst *StoreInst::clone_impl() const {
   3551   return new StoreInst(getOperand(0), getOperand(1), isVolatile(),
   3552                        getAlignment(), getOrdering(), getSynchScope());
   3553 
   3554 }
   3555 
   3556 AtomicCmpXchgInst *AtomicCmpXchgInst::clone_impl() const {
   3557   AtomicCmpXchgInst *Result =
   3558     new AtomicCmpXchgInst(getOperand(0), getOperand(1), getOperand(2),
   3559                           getSuccessOrdering(), getFailureOrdering(),
   3560                           getSynchScope());
   3561   Result->setVolatile(isVolatile());
   3562   Result->setWeak(isWeak());
   3563   return Result;
   3564 }
   3565 
   3566 AtomicRMWInst *AtomicRMWInst::clone_impl() const {
   3567   AtomicRMWInst *Result =
   3568     new AtomicRMWInst(getOperation(),getOperand(0), getOperand(1),
   3569                       getOrdering(), getSynchScope());
   3570   Result->setVolatile(isVolatile());
   3571   return Result;
   3572 }
   3573 
   3574 FenceInst *FenceInst::clone_impl() const {
   3575   return new FenceInst(getContext(), getOrdering(), getSynchScope());
   3576 }
   3577 
   3578 TruncInst *TruncInst::clone_impl() const {
   3579   return new TruncInst(getOperand(0), getType());
   3580 }
   3581 
   3582 ZExtInst *ZExtInst::clone_impl() const {
   3583   return new ZExtInst(getOperand(0), getType());
   3584 }
   3585 
   3586 SExtInst *SExtInst::clone_impl() const {
   3587   return new SExtInst(getOperand(0), getType());
   3588 }
   3589 
   3590 FPTruncInst *FPTruncInst::clone_impl() const {
   3591   return new FPTruncInst(getOperand(0), getType());
   3592 }
   3593 
   3594 FPExtInst *FPExtInst::clone_impl() const {
   3595   return new FPExtInst(getOperand(0), getType());
   3596 }
   3597 
   3598 UIToFPInst *UIToFPInst::clone_impl() const {
   3599   return new UIToFPInst(getOperand(0), getType());
   3600 }
   3601 
   3602 SIToFPInst *SIToFPInst::clone_impl() const {
   3603   return new SIToFPInst(getOperand(0), getType());
   3604 }
   3605 
   3606 FPToUIInst *FPToUIInst::clone_impl() const {
   3607   return new FPToUIInst(getOperand(0), getType());
   3608 }
   3609 
   3610 FPToSIInst *FPToSIInst::clone_impl() const {
   3611   return new FPToSIInst(getOperand(0), getType());
   3612 }
   3613 
   3614 PtrToIntInst *PtrToIntInst::clone_impl() const {
   3615   return new PtrToIntInst(getOperand(0), getType());
   3616 }
   3617 
   3618 IntToPtrInst *IntToPtrInst::clone_impl() const {
   3619   return new IntToPtrInst(getOperand(0), getType());
   3620 }
   3621 
   3622 BitCastInst *BitCastInst::clone_impl() const {
   3623   return new BitCastInst(getOperand(0), getType());
   3624 }
   3625 
   3626 AddrSpaceCastInst *AddrSpaceCastInst::clone_impl() const {
   3627   return new AddrSpaceCastInst(getOperand(0), getType());
   3628 }
   3629 
   3630 CallInst *CallInst::clone_impl() const {
   3631   return  new(getNumOperands()) CallInst(*this);
   3632 }
   3633 
   3634 SelectInst *SelectInst::clone_impl() const {
   3635   return SelectInst::Create(getOperand(0), getOperand(1), getOperand(2));
   3636 }
   3637 
   3638 VAArgInst *VAArgInst::clone_impl() const {
   3639   return new VAArgInst(getOperand(0), getType());
   3640 }
   3641 
   3642 ExtractElementInst *ExtractElementInst::clone_impl() const {
   3643   return ExtractElementInst::Create(getOperand(0), getOperand(1));
   3644 }
   3645 
   3646 InsertElementInst *InsertElementInst::clone_impl() const {
   3647   return InsertElementInst::Create(getOperand(0), getOperand(1), getOperand(2));
   3648 }
   3649 
   3650 ShuffleVectorInst *ShuffleVectorInst::clone_impl() const {
   3651   return new ShuffleVectorInst(getOperand(0), getOperand(1), getOperand(2));
   3652 }
   3653 
   3654 PHINode *PHINode::clone_impl() const {
   3655   return new PHINode(*this);
   3656 }
   3657 
   3658 LandingPadInst *LandingPadInst::clone_impl() const {
   3659   return new LandingPadInst(*this);
   3660 }
   3661 
   3662 ReturnInst *ReturnInst::clone_impl() const {
   3663   return new(getNumOperands()) ReturnInst(*this);
   3664 }
   3665 
   3666 BranchInst *BranchInst::clone_impl() const {
   3667   return new(getNumOperands()) BranchInst(*this);
   3668 }
   3669 
   3670 SwitchInst *SwitchInst::clone_impl() const {
   3671   return new SwitchInst(*this);
   3672 }
   3673 
   3674 IndirectBrInst *IndirectBrInst::clone_impl() const {
   3675   return new IndirectBrInst(*this);
   3676 }
   3677 
   3678 
   3679 InvokeInst *InvokeInst::clone_impl() const {
   3680   return new(getNumOperands()) InvokeInst(*this);
   3681 }
   3682 
   3683 ResumeInst *ResumeInst::clone_impl() const {
   3684   return new(1) ResumeInst(*this);
   3685 }
   3686 
   3687 UnreachableInst *UnreachableInst::clone_impl() const {
   3688   LLVMContext &Context = getContext();
   3689   return new UnreachableInst(Context);
   3690 }
   3691