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      1 //===---- IRBuilder.cpp - Builder for LLVM Instrs -------------------------===//
      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 the IRBuilder class, which is used as a convenient way
     11 // to create LLVM instructions with a consistent and simplified interface.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "llvm/IR/Function.h"
     16 #include "llvm/IR/GlobalVariable.h"
     17 #include "llvm/IR/IRBuilder.h"
     18 #include "llvm/IR/Intrinsics.h"
     19 #include "llvm/IR/LLVMContext.h"
     20 using namespace llvm;
     21 
     22 /// CreateGlobalString - Make a new global variable with an initializer that
     23 /// has array of i8 type filled in with the nul terminated string value
     24 /// specified.  If Name is specified, it is the name of the global variable
     25 /// created.
     26 Value *IRBuilderBase::CreateGlobalString(StringRef Str, const Twine &Name) {
     27   Constant *StrConstant = ConstantDataArray::getString(Context, Str);
     28   Module &M = *BB->getParent()->getParent();
     29   GlobalVariable *GV = new GlobalVariable(M, StrConstant->getType(),
     30                                           true, GlobalValue::PrivateLinkage,
     31                                           StrConstant);
     32   GV->setName(Name);
     33   GV->setUnnamedAddr(true);
     34   return GV;
     35 }
     36 
     37 Type *IRBuilderBase::getCurrentFunctionReturnType() const {
     38   assert(BB && BB->getParent() && "No current function!");
     39   return BB->getParent()->getReturnType();
     40 }
     41 
     42 Value *IRBuilderBase::getCastedInt8PtrValue(Value *Ptr) {
     43   PointerType *PT = cast<PointerType>(Ptr->getType());
     44   if (PT->getElementType()->isIntegerTy(8))
     45     return Ptr;
     46 
     47   // Otherwise, we need to insert a bitcast.
     48   PT = getInt8PtrTy(PT->getAddressSpace());
     49   BitCastInst *BCI = new BitCastInst(Ptr, PT, "");
     50   BB->getInstList().insert(InsertPt, BCI);
     51   SetInstDebugLocation(BCI);
     52   return BCI;
     53 }
     54 
     55 static CallInst *createCallHelper(Value *Callee, ArrayRef<Value *> Ops,
     56                                   IRBuilderBase *Builder) {
     57   CallInst *CI = CallInst::Create(Callee, Ops, "");
     58   Builder->GetInsertBlock()->getInstList().insert(Builder->GetInsertPoint(),CI);
     59   Builder->SetInstDebugLocation(CI);
     60   return CI;
     61 }
     62 
     63 CallInst *IRBuilderBase::
     64 CreateMemSet(Value *Ptr, Value *Val, Value *Size, unsigned Align,
     65              bool isVolatile, MDNode *TBAATag) {
     66   Ptr = getCastedInt8PtrValue(Ptr);
     67   Value *Ops[] = { Ptr, Val, Size, getInt32(Align), getInt1(isVolatile) };
     68   Type *Tys[] = { Ptr->getType(), Size->getType() };
     69   Module *M = BB->getParent()->getParent();
     70   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memset, Tys);
     71 
     72   CallInst *CI = createCallHelper(TheFn, Ops, this);
     73 
     74   // Set the TBAA info if present.
     75   if (TBAATag)
     76     CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
     77 
     78   return CI;
     79 }
     80 
     81 CallInst *IRBuilderBase::
     82 CreateMemCpy(Value *Dst, Value *Src, Value *Size, unsigned Align,
     83              bool isVolatile, MDNode *TBAATag, MDNode *TBAAStructTag) {
     84   Dst = getCastedInt8PtrValue(Dst);
     85   Src = getCastedInt8PtrValue(Src);
     86 
     87   Value *Ops[] = { Dst, Src, Size, getInt32(Align), getInt1(isVolatile) };
     88   Type *Tys[] = { Dst->getType(), Src->getType(), Size->getType() };
     89   Module *M = BB->getParent()->getParent();
     90   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memcpy, Tys);
     91 
     92   CallInst *CI = createCallHelper(TheFn, Ops, this);
     93 
     94   // Set the TBAA info if present.
     95   if (TBAATag)
     96     CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
     97 
     98   // Set the TBAA Struct info if present.
     99   if (TBAAStructTag)
    100     CI->setMetadata(LLVMContext::MD_tbaa_struct, TBAAStructTag);
    101 
    102   return CI;
    103 }
    104 
    105 CallInst *IRBuilderBase::
    106 CreateMemMove(Value *Dst, Value *Src, Value *Size, unsigned Align,
    107               bool isVolatile, MDNode *TBAATag) {
    108   Dst = getCastedInt8PtrValue(Dst);
    109   Src = getCastedInt8PtrValue(Src);
    110 
    111   Value *Ops[] = { Dst, Src, Size, getInt32(Align), getInt1(isVolatile) };
    112   Type *Tys[] = { Dst->getType(), Src->getType(), Size->getType() };
    113   Module *M = BB->getParent()->getParent();
    114   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::memmove, Tys);
    115 
    116   CallInst *CI = createCallHelper(TheFn, Ops, this);
    117 
    118   // Set the TBAA info if present.
    119   if (TBAATag)
    120     CI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
    121 
    122   return CI;
    123 }
    124 
    125 CallInst *IRBuilderBase::CreateLifetimeStart(Value *Ptr, ConstantInt *Size) {
    126   assert(isa<PointerType>(Ptr->getType()) &&
    127          "lifetime.start only applies to pointers.");
    128   Ptr = getCastedInt8PtrValue(Ptr);
    129   if (!Size)
    130     Size = getInt64(-1);
    131   else
    132     assert(Size->getType() == getInt64Ty() &&
    133            "lifetime.start requires the size to be an i64");
    134   Value *Ops[] = { Size, Ptr };
    135   Module *M = BB->getParent()->getParent();
    136   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::lifetime_start);
    137   return createCallHelper(TheFn, Ops, this);
    138 }
    139 
    140 CallInst *IRBuilderBase::CreateLifetimeEnd(Value *Ptr, ConstantInt *Size) {
    141   assert(isa<PointerType>(Ptr->getType()) &&
    142          "lifetime.end only applies to pointers.");
    143   Ptr = getCastedInt8PtrValue(Ptr);
    144   if (!Size)
    145     Size = getInt64(-1);
    146   else
    147     assert(Size->getType() == getInt64Ty() &&
    148            "lifetime.end requires the size to be an i64");
    149   Value *Ops[] = { Size, Ptr };
    150   Module *M = BB->getParent()->getParent();
    151   Value *TheFn = Intrinsic::getDeclaration(M, Intrinsic::lifetime_end);
    152   return createCallHelper(TheFn, Ops, this);
    153 }
    154