C++ StoreInst::getAlignment方法代码示例

bool Scalarizer::visitStoreInst(StoreInst &SI) {
  if (!ScalarizeLoadStore)
    return false;
  if (!SI.isSimple())
    return false;

  VectorLayout Layout;
  Value *FullValue = SI.getValueOperand();
  if (!getVectorLayout(FullValue->getType(), SI.getAlignment(), Layout))
    return false;

  unsigned NumElems = Layout.VecTy->getNumElements();
  IRBuilder<> Builder(SI.getParent(), &SI);
  Scatterer Ptr = scatter(&SI, SI.getPointerOperand());
  Scatterer Val = scatter(&SI, FullValue);

  ValueVector Stores;
  Stores.resize(NumElems);
  for (unsigned I = 0; I < NumElems; ++I) {
    unsigned Align = Layout.getElemAlign(I);
    Stores[I] = Builder.CreateAlignedStore(Val[I], Ptr[I], Align);
  }
  transferMetadata(&SI, Stores);
  return true;
}

/// \brief Combine stores to match the type of value being stored.
///
/// The core idea here is that the memory does not have any intrinsic type and
/// where we can we should match the type of a store to the type of value being
/// stored.
///
/// However, this routine must never change the width of a store or the number of
/// stores as that would introduce a semantic change. This combine is expected to
/// be a semantic no-op which just allows stores to more closely model the types
/// of their incoming values.
///
/// Currently, we also refuse to change the precise type used for an atomic or
/// volatile store. This is debatable, and might be reasonable to change later.
/// However, it is risky in case some backend or other part of LLVM is relying
/// on the exact type stored to select appropriate atomic operations.
///
/// \returns true if the store was successfully combined away. This indicates
/// the caller must erase the store instruction. We have to let the caller erase
/// the store instruction sas otherwise there is no way to signal whether it was
/// combined or not: IC.EraseInstFromFunction returns a null pointer.
static bool combineStoreToValueType(InstCombiner &IC, StoreInst &SI) {
  // FIXME: We could probably with some care handle both volatile and atomic
  // stores here but it isn't clear that this is important.
  if (!SI.isSimple())
    return false;

  Value *Ptr = SI.getPointerOperand();
  Value *V = SI.getValueOperand();
  unsigned AS = SI.getPointerAddressSpace();
  SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
  SI.getAllMetadata(MD);

  // Fold away bit casts of the stored value by storing the original type.
  if (auto *BC = dyn_cast<BitCastInst>(V)) {
    V = BC->getOperand(0);
    StoreInst *NewStore = IC.Builder->CreateAlignedStore(
        V, IC.Builder->CreateBitCast(Ptr, V->getType()->getPointerTo(AS)),
        SI.getAlignment());
    for (const auto &MDPair : MD) {
      unsigned ID = MDPair.first;
      MDNode *N = MDPair.second;
      // Note, essentially every kind of metadata should be preserved here! This
      // routine is supposed to clone a store instruction changing *only its
      // type*. The only metadata it makes sense to drop is metadata which is
      // invalidated when the pointer type changes. This should essentially
      // never be the case in LLVM, but we explicitly switch over only known
      // metadata to be conservatively correct. If you are adding metadata to
      // LLVM which pertains to stores, you almost certainly want to add it
      // here.
      switch (ID) {
      case LLVMContext::MD_dbg:
      case LLVMContext::MD_tbaa:
      case LLVMContext::MD_prof:
      case LLVMContext::MD_fpmath:
      case LLVMContext::MD_tbaa_struct:
      case LLVMContext::MD_alias_scope:
      case LLVMContext::MD_noalias:
      case LLVMContext::MD_nontemporal:
      case LLVMContext::MD_mem_parallel_loop_access:
      case LLVMContext::MD_nonnull:
        // All of these directly apply.
        NewStore->setMetadata(ID, N);
        break;

      case LLVMContext::MD_invariant_load:
      case LLVMContext::MD_range:
        break;
      }
    }
    return true;
  }

  // FIXME: We should also canonicalize loads of vectors when their elements are
  // cast to other types.
  return false;
}

///   store {atomic|volatile} T %val, T* %ptr memory_order, align sizeof(T)
/// becomes:
///   call void @llvm.nacl.atomic.store.i<size>(%val, %ptr, memory_order)
void AtomicVisitor::visitStoreInst(StoreInst &I) {
  return; // XXX EMSCRIPTEN
  if (I.isSimple())
    return;
  PointerHelper<StoreInst> PH(*this, I);
  const NaCl::AtomicIntrinsics::AtomicIntrinsic *Intrinsic =
      findAtomicIntrinsic(I, Intrinsic::nacl_atomic_store, PH.PET);
  checkAlignment(I, I.getAlignment(), PH.BitSize / CHAR_BIT);
  Value *V = I.getValueOperand();
  if (!V->getType()->isIntegerTy()) {
    // The store isn't of an integer type. We define atomics in terms of
    // integers, so bitcast the value to store to an integer of the
    // proper width.
    CastInst *Cast = createCast(I, V, Type::getIntNTy(C, PH.BitSize),
                                V->getName() + ".cast");
    Cast->setDebugLoc(I.getDebugLoc());
    V = Cast;
  }
  checkSizeMatchesType(I, PH.BitSize, V->getType());
  Value *Args[] = {V, PH.P, freezeMemoryOrder(I, I.getOrdering())};
  replaceInstructionWithIntrinsicCall(I, Intrinsic, PH.OriginalPET, PH.PET,
                                      Args);
}

void Lint::visitStoreInst(StoreInst &I) {
  visitMemoryReference(I, I.getPointerOperand(),
                       DL->getTypeStoreSize(I.getOperand(0)->getType()),
                       I.getAlignment(),
                       I.getOperand(0)->getType(), MemRef::Write);
}

// Lowers this interleaved access group into X86-specific
// instructions/intrinsics.
bool X86InterleavedAccessGroup::lowerIntoOptimizedSequence() {
  SmallVector<Instruction *, 4> DecomposedVectors;
  SmallVector<Value *, 4> TransposedVectors;
  VectorType *ShuffleTy = Shuffles[0]->getType();

  if (isa<LoadInst>(Inst)) {
    // Try to generate target-sized register(/instruction).
    decompose(Inst, Factor, ShuffleTy, DecomposedVectors);

    Type *ShuffleEltTy = Inst->getType();
    unsigned NumSubVecElems = ShuffleEltTy->getVectorNumElements() / Factor;
    // Perform matrix-transposition in order to compute interleaved
    // results by generating some sort of (optimized) target-specific
    // instructions.

    switch (NumSubVecElems) {
    default:
      return false;
    case 4:
      transpose_4x4(DecomposedVectors, TransposedVectors);
      break;
    case 8:
    case 16:
    case 32:
      deinterleave8bitStride3(DecomposedVectors, TransposedVectors,
                              NumSubVecElems);
      break;
    }

    // Now replace the unoptimized-interleaved-vectors with the
    // transposed-interleaved vectors.
    for (unsigned i = 0, e = Shuffles.size(); i < e; ++i)
      Shuffles[i]->replaceAllUsesWith(TransposedVectors[Indices[i]]);

    return true;
  }

  Type *ShuffleEltTy = ShuffleTy->getVectorElementType();
  unsigned NumSubVecElems = ShuffleTy->getVectorNumElements() / Factor;

  // Lower the interleaved stores:
  //   1. Decompose the interleaved wide shuffle into individual shuffle
  //   vectors.
  decompose(Shuffles[0], Factor, VectorType::get(ShuffleEltTy, NumSubVecElems),
            DecomposedVectors);

  //   2. Transpose the interleaved-vectors into vectors of contiguous
  //      elements.
  switch (NumSubVecElems) {
  case 4:
    transpose_4x4(DecomposedVectors, TransposedVectors);
    break;
  case 16:
  case 32:
    interleave8bitStride4(DecomposedVectors, TransposedVectors, NumSubVecElems);
    break;
  default:
    return false;
  }

  //   3. Concatenate the contiguous-vectors back into a wide vector.
  Value *WideVec = concatenateVectors(Builder, TransposedVectors);

  //   4. Generate a store instruction for wide-vec.
  StoreInst *SI = cast<StoreInst>(Inst);
  Builder.CreateAlignedStore(WideVec, SI->getPointerOperand(),
                             SI->getAlignment());

  return true;
}

//.........这里部分代码省略.........
  if (++PI != pred_end(DestBB))
    return false;

  // Bail out if all the relevant blocks aren't distinct (this can happen,
  // for example, if SI is in an infinite loop)
  if (StoreBB == DestBB || OtherBB == DestBB)
    return false;

  // Verify that the other block ends in a branch and is not otherwise empty.
  BasicBlock::iterator BBI(OtherBB->getTerminator());
  BranchInst *OtherBr = dyn_cast<BranchInst>(BBI);
  if (!OtherBr || BBI == OtherBB->begin())
    return false;

  // If the other block ends in an unconditional branch, check for the 'if then
  // else' case.  there is an instruction before the branch.
  StoreInst *OtherStore = nullptr;
  if (OtherBr->isUnconditional()) {
    --BBI;
    // Skip over debugging info.
    while (isa<DbgInfoIntrinsic>(BBI) ||
           (isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy())) {
      if (BBI==OtherBB->begin())
        return false;
      --BBI;
    }
    // If this isn't a store, isn't a store to the same location, or is not the
    // right kind of store, bail out.
    OtherStore = dyn_cast<StoreInst>(BBI);
    if (!OtherStore || OtherStore->getOperand(1) != SI.getOperand(1) ||
        !SI.isSameOperationAs(OtherStore))
      return false;
  } else {
    // Otherwise, the other block ended with a conditional branch. If one of the
    // destinations is StoreBB, then we have the if/then case.
    if (OtherBr->getSuccessor(0) != StoreBB &&
        OtherBr->getSuccessor(1) != StoreBB)
      return false;

    // Okay, we know that OtherBr now goes to Dest and StoreBB, so this is an
    // if/then triangle.  See if there is a store to the same ptr as SI that
    // lives in OtherBB.
    for (;; --BBI) {
      // Check to see if we find the matching store.
      if ((OtherStore = dyn_cast<StoreInst>(BBI))) {
        if (OtherStore->getOperand(1) != SI.getOperand(1) ||
            !SI.isSameOperationAs(OtherStore))
          return false;
        break;
      }
      // If we find something that may be using or overwriting the stored
      // value, or if we run out of instructions, we can't do the xform.
      if (BBI->mayReadFromMemory() || BBI->mayWriteToMemory() ||
          BBI == OtherBB->begin())
        return false;
    }

    // In order to eliminate the store in OtherBr, we have to
    // make sure nothing reads or overwrites the stored value in
    // StoreBB.
    for (BasicBlock::iterator I = StoreBB->begin(); &*I != &SI; ++I) {
      // FIXME: This should really be AA driven.
      if (I->mayReadFromMemory() || I->mayWriteToMemory())
        return false;
    }
  }

  // Insert a PHI node now if we need it.
  Value *MergedVal = OtherStore->getOperand(0);
  if (MergedVal != SI.getOperand(0)) {
    PHINode *PN = PHINode::Create(MergedVal->getType(), 2, "storemerge");
    PN->addIncoming(SI.getOperand(0), SI.getParent());
    PN->addIncoming(OtherStore->getOperand(0), OtherBB);
    MergedVal = InsertNewInstBefore(PN, DestBB->front());
  }

  // Advance to a place where it is safe to insert the new store and
  // insert it.
  BBI = DestBB->getFirstInsertionPt();
  StoreInst *NewSI = new StoreInst(MergedVal, SI.getOperand(1),
                                   SI.isVolatile(),
                                   SI.getAlignment(),
                                   SI.getOrdering(),
                                   SI.getSynchScope());
  InsertNewInstBefore(NewSI, *BBI);
  NewSI->setDebugLoc(OtherStore->getDebugLoc());

  // If the two stores had AA tags, merge them.
  AAMDNodes AATags;
  SI.getAAMetadata(AATags);
  if (AATags) {
    OtherStore->getAAMetadata(AATags, /* Merge = */ true);
    NewSI->setAAMetadata(AATags);
  }

  // Nuke the old stores.
  EraseInstFromFunction(SI);
  EraseInstFromFunction(*OtherStore);
  return true;
}

unsigned CostModelAnalysis::getInstructionCost(Instruction *I) const {
  if (!VTTI)
    return -1;

  switch (I->getOpcode()) {
  case Instruction::Ret:
  case Instruction::PHI:
  case Instruction::Br: {
    return VTTI->getCFInstrCost(I->getOpcode());
  }
  case Instruction::Add:
  case Instruction::FAdd:
  case Instruction::Sub:
  case Instruction::FSub:
  case Instruction::Mul:
  case Instruction::FMul:
  case Instruction::UDiv:
  case Instruction::SDiv:
  case Instruction::FDiv:
  case Instruction::URem:
  case Instruction::SRem:
  case Instruction::FRem:
  case Instruction::Shl:
  case Instruction::LShr:
  case Instruction::AShr:
  case Instruction::And:
  case Instruction::Or:
  case Instruction::Xor: {
    return VTTI->getArithmeticInstrCost(I->getOpcode(), I->getType());
  }
  case Instruction::Select: {
    SelectInst *SI = cast<SelectInst>(I);
    Type *CondTy = SI->getCondition()->getType();
    return VTTI->getCmpSelInstrCost(I->getOpcode(), I->getType(), CondTy);
  }
  case Instruction::ICmp:
  case Instruction::FCmp: {
    Type *ValTy = I->getOperand(0)->getType();
    return VTTI->getCmpSelInstrCost(I->getOpcode(), ValTy);
  }
  case Instruction::Store: {
    StoreInst *SI = cast<StoreInst>(I);
    Type *ValTy = SI->getValueOperand()->getType();
    return VTTI->getMemoryOpCost(I->getOpcode(), ValTy,
                                 SI->getAlignment(),
                                 SI->getPointerAddressSpace());
  }
  case Instruction::Load: {
    LoadInst *LI = cast<LoadInst>(I);
    return VTTI->getMemoryOpCost(I->getOpcode(), I->getType(),
                                 LI->getAlignment(),
                                 LI->getPointerAddressSpace());
  }
  case Instruction::ZExt:
  case Instruction::SExt:
  case Instruction::FPToUI:
  case Instruction::FPToSI:
  case Instruction::FPExt:
  case Instruction::PtrToInt:
  case Instruction::IntToPtr:
  case Instruction::SIToFP:
  case Instruction::UIToFP:
  case Instruction::Trunc:
  case Instruction::FPTrunc:
  case Instruction::BitCast: {
    Type *SrcTy = I->getOperand(0)->getType();
    return VTTI->getCastInstrCost(I->getOpcode(), I->getType(), SrcTy);
  }
  case Instruction::ExtractElement: {
    ExtractElementInst * EEI = cast<ExtractElementInst>(I);
    ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1));
    unsigned Idx = -1;
    if (CI)
      Idx = CI->getZExtValue();
    return VTTI->getVectorInstrCost(I->getOpcode(),
                                    EEI->getOperand(0)->getType(), Idx);
  }
  case Instruction::InsertElement: {
      InsertElementInst * IE = cast<InsertElementInst>(I);
      ConstantInt *CI = dyn_cast<ConstantInt>(IE->getOperand(2));
      unsigned Idx = -1;
      if (CI)
        Idx = CI->getZExtValue();
      return VTTI->getVectorInstrCost(I->getOpcode(),
                                      IE->getType(), Idx);
    }
  default:
    // We don't have any information on this instruction.
    return -1;
  }
}

//.........这里部分代码省略.........
    // create temporary alloca space to communicate to/from.
    alloc = makeAlloca(int8Ty, "agg.tmp", insertBefore,
                       Range.End-Range.Start, Alignment);

    // Generate the old and new base pointers before we output
    // anything else.
    {
      Type* iPtrTy = TD->getIntPtrType(alloc->getType());
      Type* iNewBaseTy = TD->getIntPtrType(alloc->getType());
      oldBaseI = builder.CreatePtrToInt(StartPtr, iPtrTy, "agg.tmp.oldb.i");
      newBaseI = builder.CreatePtrToInt(alloc, iNewBaseTy, "agg.tmp.newb.i");
    }

    // If storing, do the stores we had into our alloca'd region.
    if( isStore ) {
      for (SmallVector<Instruction*, 16>::const_iterator
           SI = Range.TheStores.begin(),
           SE = Range.TheStores.end(); SI != SE; ++SI) {
        StoreInst* oldStore = cast<StoreInst>(*SI);

        if( DebugThis ) {
          errs() << "have store in range:";
          oldStore->dump();
        }

        Value* ptrToAlloc = rebasePointer(oldStore->getPointerOperand(),
                                          StartPtr, alloc, "agg.tmp",
                                          &builder, *TD, oldBaseI, newBaseI);
        // Old load must not be volatile or atomic... or we shouldn't have put
        // it in ranges
        assert(!(oldStore->isVolatile() || oldStore->isAtomic()));
        StoreInst* newStore =
          builder.CreateStore(oldStore->getValueOperand(), ptrToAlloc);
        newStore->setAlignment(oldStore->getAlignment());
        newStore->takeName(oldStore);
      }
    }

    // cast the pointer that was load/stored to i8 if necessary.
    if( StartPtr->getType()->getPointerElementType() == int8Ty ) {
      globalPtr = StartPtr;
    } else {
      globalPtr = builder.CreatePointerCast(StartPtr, globalInt8PtrTy, "agg.cast");
    }

    // Get a Constant* for the length.
    Constant* len = ConstantInt::get(sizeTy, Range.End-Range.Start, false);

    // Now add the memcpy instruction
    unsigned addrSpaceDst,addrSpaceSrc;
    addrSpaceDst = addrSpaceSrc = 0;
    if( isStore ) addrSpaceDst = globalSpace;
    if( isLoad ) addrSpaceSrc = globalSpace;

    Type *types[3];
    types[0] = PointerType::get(int8Ty, addrSpaceDst);
    types[1] = PointerType::get(int8Ty, addrSpaceSrc);
    types[2] = sizeTy;

    Function *func = Intrinsic::getDeclaration(M, Intrinsic::memcpy, types);

    Value* args[5]; // dst src len alignment isvolatile
    if( isStore ) {
      // it's a store (ie put)
      args[0] = globalPtr;
      args[1] = alloc;

Value *BoUpSLP::vectorizeTree(ValueList &VL, int VF) {
  Type *ScalarTy = VL[0]->getType();
  if (StoreInst *SI = dyn_cast<StoreInst>(VL[0]))
    ScalarTy = SI->getValueOperand()->getType();
  VectorType *VecTy = VectorType::get(ScalarTy, VF);

  // Check if all of the operands are constants or identical.
  bool AllConst = true;
  bool AllSameScalar = true;
  for (unsigned i = 0, e = VF; i < e; ++i) {
    AllConst &= !!dyn_cast<Constant>(VL[i]);
    AllSameScalar &= (VL[0] == VL[i]);
    // Must have a single use.
    Instruction *I = dyn_cast<Instruction>(VL[i]);
    if (I && (I->getNumUses() > 1 || I->getParent() != BB))
      return Scalarize(VL, VecTy);
  }

  // Is this a simple vector constant.
  if (AllConst || AllSameScalar) return Scalarize(VL, VecTy);

  // Scalarize unknown structures.
  Instruction *VL0 = dyn_cast<Instruction>(VL[0]);
  if (!VL0) return Scalarize(VL, VecTy);

  unsigned Opcode = VL0->getOpcode();
  for (unsigned i = 0, e = VF; i < e; ++i) {
    Instruction *I = dyn_cast<Instruction>(VL[i]);
    // If not all of the instructions are identical then we have to scalarize.
    if (!I || Opcode != I->getOpcode()) return Scalarize(VL, VecTy);
  }

  switch (Opcode) {
  case Instruction::Add:
  case Instruction::FAdd:
  case Instruction::Sub:
  case Instruction::FSub:
  case Instruction::Mul:
  case Instruction::FMul:
  case Instruction::UDiv:
  case Instruction::SDiv:
  case Instruction::FDiv:
  case Instruction::URem:
  case Instruction::SRem:
  case Instruction::FRem:
  case Instruction::Shl:
  case Instruction::LShr:
  case Instruction::AShr:
  case Instruction::And:
  case Instruction::Or:
  case Instruction::Xor: {
    ValueList LHSVL, RHSVL;
    for (int i = 0; i < VF; ++i) {
      RHSVL.push_back(cast<Instruction>(VL[i])->getOperand(0));
      LHSVL.push_back(cast<Instruction>(VL[i])->getOperand(1));
    }

    Value *RHS = vectorizeTree(RHSVL, VF);
    Value *LHS = vectorizeTree(LHSVL, VF);
    IRBuilder<> Builder(GetLastInstr(VL, VF));
    BinaryOperator *BinOp = dyn_cast<BinaryOperator>(VL0);
    return Builder.CreateBinOp(BinOp->getOpcode(), RHS,LHS);
  }
  case Instruction::Load: {
    LoadInst *LI = dyn_cast<LoadInst>(VL0);
    unsigned Alignment = LI->getAlignment();

    // Check if all of the loads are consecutive.
    for (unsigned i = 1, e = VF; i < e; ++i)
      if (!isConsecutiveAccess(VL[i-1], VL[i]))
        return Scalarize(VL, VecTy);

    IRBuilder<> Builder(GetLastInstr(VL, VF));
    Value *VecPtr = Builder.CreateBitCast(LI->getPointerOperand(),
                                          VecTy->getPointerTo());
    LI = Builder.CreateLoad(VecPtr);
    LI->setAlignment(Alignment);
    return LI;
  }
  case Instruction::Store: {
    StoreInst *SI = dyn_cast<StoreInst>(VL0);
    unsigned Alignment = SI->getAlignment();

    ValueList ValueOp;
    for (int i = 0; i < VF; ++i)
      ValueOp.push_back(cast<StoreInst>(VL[i])->getValueOperand());

    Value *VecValue = vectorizeTree(ValueOp, VF);

    IRBuilder<> Builder(GetLastInstr(VL, VF));
    Value *VecPtr = Builder.CreateBitCast(SI->getPointerOperand(),
                                          VecTy->getPointerTo());
    Builder.CreateStore(VecValue, VecPtr)->setAlignment(Alignment);

    for (int i = 0; i < VF; ++i)
      cast<Instruction>(VL[i])->eraseFromParent();
    return 0;
  }
  default:
    return Scalarize(VL, VecTy);
//.........这里部分代码省略.........

void Lint::visitStoreInst(StoreInst &I) {
  visitMemoryReference(I, I.getPointerOperand(), I.getAlignment(),
                  I.getOperand(0)->getType());
}