C++ IntrinsicInst::getIntrinsicID方法代码示例

static bool allPredCameFromBeginCatch(
    BasicBlock *BB, BasicBlock::reverse_iterator InstRbegin,
    IntrinsicInst **SecondEndCatch, SmallSet<BasicBlock *, 4> &VisitedBlocks) {
  VisitedBlocks.insert(BB);
  // Look for a begincatch in this block.
  for (BasicBlock::reverse_iterator RI = InstRbegin, RE = BB->rend(); RI != RE;
       ++RI) {
    IntrinsicInst *IC = dyn_cast<IntrinsicInst>(&*RI);
    if (IC && IC->getIntrinsicID() == Intrinsic::eh_begincatch)
      return true;
    // If we find another end catch before we find a begin catch, that's
    // an error.
    if (IC && IC->getIntrinsicID() == Intrinsic::eh_endcatch) {
      *SecondEndCatch = IC;
      return false;
    }
    // If we encounter a landingpad instruction, the search failed.
    if (isa<LandingPadInst>(*RI))
      return false;
  }
  // If while searching we find a block with no predeccesors,
  // the search failed.
  if (pred_empty(BB))
    return false;
  // Search any predecessors we haven't seen before.
  for (BasicBlock *Pred : predecessors(BB)) {
    if (VisitedBlocks.count(Pred))
      continue;
    if (!allPredCameFromBeginCatch(Pred, Pred->rbegin(), SecondEndCatch,
                                   VisitedBlocks))
      return false;
  }
  return true;
}

static bool
allSuccessorsReachEndCatch(BasicBlock *BB, BasicBlock::iterator InstBegin,
                           IntrinsicInst **SecondBeginCatch,
                           SmallSet<BasicBlock *, 4> &VisitedBlocks) {
  VisitedBlocks.insert(BB);
  for (BasicBlock::iterator I = InstBegin, E = BB->end(); I != E; ++I) {
    IntrinsicInst *IC = dyn_cast<IntrinsicInst>(I);
    if (IC && IC->getIntrinsicID() == Intrinsic::eh_endcatch)
      return true;
    // If we find another begincatch while looking for an endcatch,
    // that's also an error.
    if (IC && IC->getIntrinsicID() == Intrinsic::eh_begincatch) {
      *SecondBeginCatch = IC;
      return false;
    }
  }

  // If we reach a block with no successors while searching, the
  // search has failed.
  if (succ_empty(BB))
    return false;
  // Otherwise, search all of the successors.
  for (BasicBlock *Succ : successors(BB)) {
    if (VisitedBlocks.count(Succ))
      continue;
    if (!allSuccessorsReachEndCatch(Succ, Succ->begin(), SecondBeginCatch,
                                    VisitedBlocks))
      return false;
  }
  return true;
}

bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) {
  // Lower all uses of llvm.objectsize.*
  IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
  if (II && II->getIntrinsicID() == Intrinsic::objectsize) {
    bool Min = (cast<ConstantInt>(II->getArgOperand(1))->getZExtValue() == 1);
    const Type *ReturnTy = CI->getType();
    Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);    
    CI->replaceAllUsesWith(RetVal);
    CI->eraseFromParent();
    return true;
  }

  // From here on out we're working with named functions.
  if (CI->getCalledFunction() == 0) return false;
  
  // We'll need TargetData from here on out.
  const TargetData *TD = TLI ? TLI->getTargetData() : 0;
  if (!TD) return false;
  
  // Lower all default uses of _chk calls.  This is very similar
  // to what InstCombineCalls does, but here we are only lowering calls
  // that have the default "don't know" as the objectsize.  Anything else
  // should be left alone.
  CodeGenPrepareFortifiedLibCalls Simplifier;
  return Simplifier.fold(CI, TD);
}

bool LLVMReachingDefsAnalysis::handleIntrinsicCall(LLVMNode *callNode,
                                                   CallInst *CI,
                                                   DefMap *df)
{
    bool changed = false;
    IntrinsicInst *I = cast<IntrinsicInst>(CI);
    Value *dest;

    switch (I->getIntrinsicID())
    {
        case Intrinsic::memmove:
        case Intrinsic::memcpy:
        case Intrinsic::memset:
            dest = I->getOperand(0);
            break;
        default:
            return handleUndefinedCall(callNode, CI, df);
    }

    LLVMNode *destNode = getOperand(callNode, dest, 1);
    assert(destNode && "No operand for intrinsic call");

    for (const Pointer& ptr : destNode->getPointsTo()) {
        // we could compute all the concrete offsets, but
        // these functions usually set the whole memory,
        // so if we use UNKNOWN_OFFSET, the effect is the same
        changed |= df->add(Pointer(ptr.obj, UNKNOWN_OFFSET), callNode);
    }

    return changed;
}

/// getLocForWrite - Return a Location stored to by the specified instruction.
/// If isRemovable returns true, this function and getLocForRead completely
/// describe the memory operations for this instruction.
static MemoryLocation getLocForWrite(Instruction *Inst, AliasAnalysis &AA) {
  if (StoreInst *SI = dyn_cast<StoreInst>(Inst))
    return MemoryLocation::get(SI);

  if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(Inst)) {
    // memcpy/memmove/memset.
    MemoryLocation Loc = MemoryLocation::getForDest(MI);
    return Loc;
  }

  IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst);
  if (!II)
    return MemoryLocation();

  switch (II->getIntrinsicID()) {
  default:
    return MemoryLocation(); // Unhandled intrinsic.
  case Intrinsic::init_trampoline:
    // FIXME: We don't know the size of the trampoline, so we can't really
    // handle it here.
    return MemoryLocation(II->getArgOperand(0));
  case Intrinsic::lifetime_end: {
    uint64_t Len = cast<ConstantInt>(II->getArgOperand(0))->getZExtValue();
    return MemoryLocation(II->getArgOperand(1), Len);
  }
  }
}

bool AMDGPUCodeGenPrepare::promoteUniformBitreverseToI32(
    IntrinsicInst &I) const {
  assert(I.getIntrinsicID() == Intrinsic::bitreverse &&
         "I must be bitreverse intrinsic");
  assert(needsPromotionToI32(I.getType()) &&
         "I does not need promotion to i32");

  IRBuilder<> Builder(&I);
  Builder.SetCurrentDebugLocation(I.getDebugLoc());

  Type *I32Ty = getI32Ty(Builder, I.getType());
  Function *I32 =
      Intrinsic::getDeclaration(Mod, Intrinsic::bitreverse, { I32Ty });
  Value *ExtOp = Builder.CreateZExt(I.getOperand(0), I32Ty);
  Value *ExtRes = Builder.CreateCall(I32, { ExtOp });
  Value *LShrOp =
      Builder.CreateLShr(ExtRes, 32 - getBaseElementBitWidth(I.getType()));
  Value *TruncRes =
      Builder.CreateTrunc(LShrOp, I.getType());

  I.replaceAllUsesWith(TruncRes);
  I.eraseFromParent();

  return true;
}

/// Escape RegNode so that we can access it from child handlers. Find the call
/// to frameescape, if any, in the entry block and append RegNode to the list
/// of arguments.
int WinEHStatePass::escapeRegNode(Function &F) {
  // Find the call to frameescape and extract its arguments.
  IntrinsicInst *EscapeCall = nullptr;
  for (Instruction &I : F.getEntryBlock()) {
    IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
    if (II && II->getIntrinsicID() == Intrinsic::frameescape) {
      EscapeCall = II;
      break;
    }
  }
  SmallVector<Value *, 8> Args;
  if (EscapeCall) {
    auto Ops = EscapeCall->arg_operands();
    Args.append(Ops.begin(), Ops.end());
  }
  Args.push_back(RegNode);

  // Replace the call (if it exists) with new one. Otherwise, insert at the end
  // of the entry block.
  IRBuilder<> Builder(&F.getEntryBlock(),
                      EscapeCall ? EscapeCall : F.getEntryBlock().end());
  Builder.CreateCall(FrameEscape, Args);
  if (EscapeCall)
    EscapeCall->eraseFromParent();
  return Args.size() - 1;
}

static void detectLog2OfHalf(Value *&Op, Value *&Y, IntrinsicInst *&Log2) {

   if (!Op->hasOneUse())
     return;

   IntrinsicInst *II = dyn_cast<IntrinsicInst>(Op);
   if (!II)
     return;
   if (II->getIntrinsicID() != Intrinsic::log2 || !II->hasUnsafeAlgebra())
     return;
   Log2 = II;

   Value *OpLog2Of = II->getArgOperand(0);
   if (!OpLog2Of->hasOneUse())
     return;

   Instruction *I = dyn_cast<Instruction>(OpLog2Of);
   if (!I)
     return;
   if (I->getOpcode() != Instruction::FMul || !I->hasUnsafeAlgebra())
     return;

   if (match(I->getOperand(0), m_SpecificFP(0.5)))
     Y = I->getOperand(1);
   else if (match(I->getOperand(1), m_SpecificFP(0.5)))
     Y = I->getOperand(0);
}

static bool isCallPromotable(CallInst *CI) {
  // TODO: We might be able to handle some cases where the callee is a
  // constantexpr bitcast of a function.
  if (!CI->getCalledFunction())
    return false;

  IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
  if (!II)
    return false;

  switch (II->getIntrinsicID()) {
  case Intrinsic::memcpy:
  case Intrinsic::memmove:
  case Intrinsic::memset:
  case Intrinsic::lifetime_start:
  case Intrinsic::lifetime_end:
  case Intrinsic::invariant_start:
  case Intrinsic::invariant_end:
  case Intrinsic::invariant_group_barrier:
  case Intrinsic::objectsize:
    return true;
  default:
    return false;
  }
}

/// \brief Split sadd.with.overflow into add + sadd.with.overflow to allow
/// analysis and optimization.
///
/// \return A new value representing the non-overflowing add if possible,
/// otherwise return the original value.
Instruction *SimplifyIndvar::splitOverflowIntrinsic(Instruction *IVUser,
                                                    const DominatorTree *DT) {
  IntrinsicInst *II = dyn_cast<IntrinsicInst>(IVUser);
  if (!II || II->getIntrinsicID() != Intrinsic::sadd_with_overflow)
    return IVUser;

  // Find a branch guarded by the overflow check.
  BranchInst *Branch = 0;
  Instruction *AddVal = 0;
  for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
       UI != E; ++UI) {
    if (ExtractValueInst *ExtractInst = dyn_cast<ExtractValueInst>(*UI)) {
      if (ExtractInst->getNumIndices() != 1)
        continue;
      if (ExtractInst->getIndices()[0] == 0)
        AddVal = ExtractInst;
      else if (ExtractInst->getIndices()[0] == 1 && ExtractInst->hasOneUse())
        Branch = dyn_cast<BranchInst>(ExtractInst->use_back());
    }
  }
  if (!AddVal || !Branch)
    return IVUser;

  BasicBlock *ContinueBB = Branch->getSuccessor(1);
  if (llvm::next(pred_begin(ContinueBB)) != pred_end(ContinueBB))
    return IVUser;

  // Check if all users of the add are provably NSW.
  bool AllNSW = true;
  for (Value::use_iterator UI = AddVal->use_begin(), E = AddVal->use_end();
       UI != E; ++UI) {
    if (Instruction *UseInst = dyn_cast<Instruction>(*UI)) {
      BasicBlock *UseBB = UseInst->getParent();
      if (PHINode *PHI = dyn_cast<PHINode>(UseInst))
        UseBB = PHI->getIncomingBlock(UI);
      if (!DT->dominates(ContinueBB, UseBB)) {
        AllNSW = false;
        break;
      }
    }
  }
  if (!AllNSW)
    return IVUser;

  // Go for it...
  IRBuilder<> Builder(IVUser);
  Instruction *AddInst = dyn_cast<Instruction>(
    Builder.CreateNSWAdd(II->getOperand(0), II->getOperand(1)));

  // The caller expects the new add to have the same form as the intrinsic. The
  // IV operand position must be the same.
  assert((AddInst->getOpcode() == Instruction::Add &&
          AddInst->getOperand(0) == II->getOperand(0)) &&
         "Bad add instruction created from overflow intrinsic.");

  AddVal->replaceAllUsesWith(AddInst);
  DeadInsts.push_back(AddVal);
  return AddInst;
}

bool AMDGPUCodeGenPrepare::visitIntrinsicInst(IntrinsicInst &I) {
  switch (I.getIntrinsicID()) {
  case Intrinsic::bitreverse:
    return visitBitreverseIntrinsicInst(I);
  default:
    return false;
  }
}

bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) {
    BasicBlock *BB = CI->getParent();

    // Lower inline assembly if we can.
    // If we found an inline asm expession, and if the target knows how to
    // lower it to normal LLVM code, do so now.
    if (TLI && isa<InlineAsm>(CI->getCalledValue())) {
        if (TLI->ExpandInlineAsm(CI)) {
            // Avoid invalidating the iterator.
            CurInstIterator = BB->begin();
            // Avoid processing instructions out of order, which could cause
            // reuse before a value is defined.
            SunkAddrs.clear();
            return true;
        }
        // Sink address computing for memory operands into the block.
        if (OptimizeInlineAsmInst(CI))
            return true;
    }

    // Lower all uses of llvm.objectsize.*
    IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
    if (II && II->getIntrinsicID() == Intrinsic::objectsize) {
        bool Min = (cast<ConstantInt>(II->getArgOperand(1))->getZExtValue() == 1);
        Type *ReturnTy = CI->getType();
        Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);

        // Substituting this can cause recursive simplifications, which can
        // invalidate our iterator.  Use a WeakVH to hold onto it in case this
        // happens.
        WeakVH IterHandle(CurInstIterator);

        ReplaceAndSimplifyAllUses(CI, RetVal, TLI ? TLI->getTargetData() : 0,
                                  TLInfo, ModifiedDT ? 0 : DT);

        // If the iterator instruction was recursively deleted, start over at the
        // start of the block.
        if (IterHandle != CurInstIterator) {
            CurInstIterator = BB->begin();
            SunkAddrs.clear();
        }
        return true;
    }

    // From here on out we're working with named functions.
    if (CI->getCalledFunction() == 0) return false;

    // We'll need TargetData from here on out.
    const TargetData *TD = TLI ? TLI->getTargetData() : 0;
    if (!TD) return false;

    // Lower all default uses of _chk calls.  This is very similar
    // to what InstCombineCalls does, but here we are only lowering calls
    // that have the default "don't know" as the objectsize.  Anything else
    // should be left alone.
    CodeGenPrepareFortifiedLibCalls Simplifier;
    return Simplifier.fold(CI, TD);
}

void AAAnalyzer::handle_instrinsic(Instruction *inst) {
    IntrinsicInst * call = (IntrinsicInst*) inst;
    switch (call->getIntrinsicID()) {
            // Variable Argument Handling Intrinsics
        case Intrinsic::vastart:
        {
            Value * va_list_ptr = call->getArgOperand(0);
            wrapValue(va_list_ptr);
        }
            break;
        case Intrinsic::vaend:
        {
        }
            break;
        case Intrinsic::vacopy: // the same with memmove/memcpy

            //Standard C Library Intrinsics
        case Intrinsic::memmove:
        case Intrinsic::memcpy:
        {
            Value * src_ptr = call->getArgOperand(0);
            Value * dst_ptr = call->getArgOperand(1);

            DyckVertex* src_ptr_ver = wrapValue(src_ptr);
            DyckVertex* dst_ptr_ver = wrapValue(dst_ptr);

            DyckVertex* src_ver = addPtrTo(src_ptr_ver, NULL);
            DyckVertex* dst_ver = addPtrTo(dst_ptr_ver, NULL);

            makeAlias(src_ver, dst_ver);
        }
            break;
        case Intrinsic::memset:
        {
            Value * ptr = call->getArgOperand(0);
            Value * val = call->getArgOperand(1);
            addPtrTo(wrapValue(ptr), wrapValue(val));
        }
            break;
            /// @todo other C lib intrinsics

            //Accurate Garbage Collection Intrinsics
            //Code Generator Intrinsics
            //Bit Manipulation Intrinsics
            //Exception Handling Intrinsics
            //Trampoline Intrinsics
            //Memory Use Markers
            //General Intrinsics

            //Arithmetic with Overflow Intrinsics
            //Specialised Arithmetic Intrinsics
            //Half Precision Floating Point Intrinsics
            //Debugger Intrinsics
        default:break;
    }
}

/// getStoredPointerOperand - Return the pointer that is being written to.
static Value *getStoredPointerOperand(Instruction *I) {
  if (StoreInst *SI = dyn_cast<StoreInst>(I))
    return SI->getPointerOperand();
  if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I))
    return MI->getDest();

  IntrinsicInst *II = cast<IntrinsicInst>(I);
  switch (II->getIntrinsicID()) {
  default: llvm_unreachable("Unexpected intrinsic!");
  case Intrinsic::init_trampoline:
    return II->getArgOperand(0);
  }
}

/// isShortenable - Returns true if this instruction can be safely shortened in
/// length.
static bool isShortenable(Instruction *I) {
  // Don't shorten stores for now
  if (isa<StoreInst>(I))
    return false;
  
  IntrinsicInst *II = cast<IntrinsicInst>(I);
  switch (II->getIntrinsicID()) {
    default: return false;
    case Intrinsic::memset:
    case Intrinsic::memcpy:
      // Do shorten memory intrinsics.
      return true;
  }
}