C++ StoreInst::getDest方法代码示例

/// Returns the callee SILFunction called at a call site, in the case
/// that the call is transparent (as in, both that the call is marked
/// with the transparent flag and that callee function is actually transparently
/// determinable from the SIL) or nullptr otherwise. This assumes that the SIL
/// is already in SSA form.
///
/// In the case that a non-null value is returned, FullArgs contains effective
/// argument operands for the callee function.
static SILFunction *getCalleeFunction(
    SILFunction *F, FullApplySite AI, bool &IsThick,
    SmallVectorImpl<std::pair<SILValue, ParameterConvention>> &CaptureArgs,
    SmallVectorImpl<SILValue> &FullArgs, PartialApplyInst *&PartialApply) {
  IsThick = false;
  PartialApply = nullptr;
  CaptureArgs.clear();
  FullArgs.clear();

  for (const auto &Arg : AI.getArguments())
    FullArgs.push_back(Arg);
  SILValue CalleeValue = AI.getCallee();

  if (auto *LI = dyn_cast<LoadInst>(CalleeValue)) {
    // Conservatively only see through alloc_box; we assume this pass is run
    // immediately after SILGen
    auto *PBI = dyn_cast<ProjectBoxInst>(LI->getOperand());
    if (!PBI)
      return nullptr;
    auto *ABI = dyn_cast<AllocBoxInst>(PBI->getOperand());
    if (!ABI)
      return nullptr;
    // Ensure there are no other uses of alloc_box than the project_box and
    // retains, releases.
    for (Operand *ABIUse : ABI->getUses())
      if (ABIUse->getUser() != PBI &&
          !isa<StrongRetainInst>(ABIUse->getUser()) &&
          !isa<StrongReleaseInst>(ABIUse->getUser()))
        return nullptr;

    // Scan forward from the alloc box to find the first store, which
    // (conservatively) must be in the same basic block as the alloc box
    StoreInst *SI = nullptr;
    for (auto I = SILBasicBlock::iterator(ABI), E = I->getParent()->end();
         I != E; ++I) {
      // If we find the load instruction first, then the load is loading from
      // a non-initialized alloc; this shouldn't really happen but I'm not
      // making any assumptions
      if (&*I == LI)
        return nullptr;
      if ((SI = dyn_cast<StoreInst>(I)) && SI->getDest() == PBI) {
        // We found a store that we know dominates the load; now ensure there
        // are no other uses of the project_box except loads.
        for (Operand *PBIUse : PBI->getUses())
          if (PBIUse->getUser() != SI && !isa<LoadInst>(PBIUse->getUser()))
            return nullptr;
        // We can conservatively see through the store
        break;
      }
    }
    if (!SI)
      return nullptr;
    CalleeValue = SI->getSrc();
  }

  // PartialApply/ThinToThick -> ConvertFunction patterns are generated
  // by @noescape closures.
  //
  // FIXME: We don't currently handle mismatched return types, however, this
  // would be a good optimization to handle and would be as simple as inserting
  // a cast.
  auto skipFuncConvert = [](SILValue CalleeValue) {
    // We can also allow a thin @escape to noescape conversion as such:
    // %1 = function_ref @thin_closure_impl : [email protected](thin) () -> ()
    // %2 = convert_function %1 :
    //      [email protected](thin) () -> () to [email protected](thin) @noescape () -> ()
    // %3 = thin_to_thick_function %2 :
    //  [email protected](thin) @noescape () -> () to
    //            [email protected] @callee_guaranteed () -> ()
    // %4 = apply %3() : [email protected] @callee_guaranteed () -> ()
    if (auto *ThinToNoescapeCast = dyn_cast<ConvertFunctionInst>(CalleeValue)) {
      auto FromCalleeTy =
          ThinToNoescapeCast->getOperand()->getType().castTo<SILFunctionType>();
      if (FromCalleeTy->getExtInfo().hasContext())
        return CalleeValue;
      auto ToCalleeTy = ThinToNoescapeCast->getType().castTo<SILFunctionType>();
      auto EscapingCalleeTy = ToCalleeTy->getWithExtInfo(
          ToCalleeTy->getExtInfo().withNoEscape(false));
      if (FromCalleeTy != EscapingCalleeTy)
        return CalleeValue;
      return ThinToNoescapeCast->getOperand();
    }

    auto *CFI = dyn_cast<ConvertEscapeToNoEscapeInst>(CalleeValue);
    if (!CFI)
      return CalleeValue;

    // TODO: Handle argument conversion. All the code in this file needs to be
    // cleaned up and generalized. The argument conversion handling in
    // optimizeApplyOfConvertFunctionInst should apply to any combine
    // involving an apply, not just a specific pattern.
    //
//.........这里部分代码省略.........

/// \brief Removes instructions that create the callee value if they are no
/// longer necessary after inlining.
static void
cleanupCalleeValue(SILValue CalleeValue, ArrayRef<SILValue> CaptureArgs,
                   ArrayRef<SILValue> FullArgs) {
  SmallVector<SILInstruction*, 16> InstsToDelete;
  for (SILValue V : FullArgs) {
    if (SILInstruction *I = dyn_cast<SILInstruction>(V))
      if (I != CalleeValue.getDef() &&
          isInstructionTriviallyDead(I))
        InstsToDelete.push_back(I);
  }
  recursivelyDeleteTriviallyDeadInstructions(InstsToDelete, true);

  // Handle the case where the callee of the apply is a load instruction.
  if (LoadInst *LI = dyn_cast<LoadInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);
    SILInstruction *ABI = dyn_cast<AllocBoxInst>(LI->getOperand());
    assert(ABI && LI->getOperand().getResultNumber() == 1);

    // The load instruction must have no more uses left to erase it.
    if (!LI->use_empty())
      return;
    LI->eraseFromParent();

    // Look through uses of the alloc box the load is loading from to find up to
    // one store and up to one strong release.
    StoreInst *SI = nullptr;
    StrongReleaseInst *SRI = nullptr;
    for (auto UI = ABI->use_begin(), UE = ABI->use_end(); UI != UE; ++UI) {
      if (SI == nullptr && isa<StoreInst>(UI.getUser())) {
        SI = cast<StoreInst>(UI.getUser());
        assert(SI->getDest() == SILValue(ABI, 1));
      } else if (SRI == nullptr && isa<StrongReleaseInst>(UI.getUser())) {
        SRI = cast<StrongReleaseInst>(UI.getUser());
        assert(SRI->getOperand() == SILValue(ABI, 0));
      } else
        return;
    }

    // If we found a store, record its source and erase it.
    if (SI) {
      CalleeValue = SI->getSrc();
      SI->eraseFromParent();
    } else {
      CalleeValue = SILValue();
    }

    // If we found a strong release, replace it with a strong release of the
    // source of the store and erase it.
    if (SRI) {
      if (CalleeValue.isValid())
        SILBuilderWithScope(SRI)
            .emitStrongReleaseAndFold(SRI->getLoc(), CalleeValue);
      SRI->eraseFromParent();
    }

    assert(ABI->use_empty());
    ABI->eraseFromParent();
    if (!CalleeValue.isValid())
      return;
  }

  if (auto *PAI = dyn_cast<PartialApplyInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);

    SILValue Callee = PAI->getCallee();
    if (!tryDeleteDeadClosure(PAI))
      return;
    CalleeValue = Callee;
  }

  if (auto *TTTFI = dyn_cast<ThinToThickFunctionInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);
    SILValue Callee = TTTFI->getCallee();
    if (!tryDeleteDeadClosure(TTTFI))
      return;
    CalleeValue = Callee;
  }

  if (FunctionRefInst *FRI = dyn_cast<FunctionRefInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);
    if (!FRI->use_empty())
      return;
    FRI->eraseFromParent();
  }
}

/// Simplify the following two frontend patterns:
///
///   %payload_addr = init_enum_data_addr %payload_allocation
///   store %payload to %payload_addr
///   inject_enum_addr %payload_allocation, $EnumType.case
///
///   inject_enum_add %nopayload_allocation, $EnumType.case
///
/// for a concrete enum type $EnumType.case to:
///
///   %1 = enum $EnumType, $EnumType.case, %payload
///   store %1 to %payload_addr
///
///   %1 = enum $EnumType, $EnumType.case
///   store %1 to %nopayload_addr
///
/// We leave the cleaning up to mem2reg.
SILInstruction *
SILCombiner::visitInjectEnumAddrInst(InjectEnumAddrInst *IEAI) {
    // Given an inject_enum_addr of a concrete type without payload, promote it to
    // a store of an enum. Mem2reg/load forwarding will clean things up for us. We
    // can't handle the payload case here due to the flow problems caused by the
    // dependency in between the enum and its data.

    assert(IEAI->getOperand().getType().isAddress() && "Must be an address");
    Builder.setCurrentDebugScope(IEAI->getDebugScope());

    if (IEAI->getOperand().getType().isAddressOnly(IEAI->getModule())) {
        // Check for the following pattern inside the current basic block:
        // inject_enum_addr %payload_allocation, $EnumType.case1
        // ... no insns storing anything into %payload_allocation
        // select_enum_addr  %payload_allocation,
        //                   case $EnumType.case1: %Result1,
        //                   case case $EnumType.case2: %bResult2
        //                   ...
        //
        // Replace the select_enum_addr by %Result1

        auto *Term = IEAI->getParent()->getTerminator();
        if (isa<CondBranchInst>(Term) || isa<SwitchValueInst>(Term)) {
            auto BeforeTerm = prev(prev(IEAI->getParent()->end()));
            auto *SEAI = dyn_cast<SelectEnumAddrInst>(BeforeTerm);
            if (!SEAI)
                return nullptr;

            if (SEAI->getOperand() != IEAI->getOperand())
                return nullptr;

            SILBasicBlock::iterator II = IEAI->getIterator();
            StoreInst *SI = nullptr;
            for (;;) {
                SILInstruction *CI = &*II;
                if (CI == SEAI)
                    break;
                ++II;
                SI = dyn_cast<StoreInst>(CI);
                if (SI) {
                    if (SI->getDest() == IEAI->getOperand())
                        return nullptr;
                }
                // Allow all instructions inbetween, which don't have any dependency to
                // the store.
                if (AA->mayWriteToMemory(&*II, IEAI->getOperand()))
                    return nullptr;
            }

            auto *InjectedEnumElement = IEAI->getElement();
            auto Result = SEAI->getCaseResult(InjectedEnumElement);

            // Replace select_enum_addr by the result
            replaceInstUsesWith(*SEAI, Result.getDef());
            return nullptr;
        }

        // Check for the following pattern inside the current basic block:
        // inject_enum_addr %payload_allocation, $EnumType.case1
        // ... no insns storing anything into %payload_allocation
        // switch_enum_addr  %payload_allocation,
        //                   case $EnumType.case1: %bbX,
        //                   case case $EnumType.case2: %bbY
        //                   ...
        //
        // Replace the switch_enum_addr by select_enum_addr, switch_value.
        if (auto *SEI = dyn_cast<SwitchEnumAddrInst>(Term)) {
            if (SEI->getOperand() != IEAI->getOperand())
                return nullptr;

            SILBasicBlock::iterator II = IEAI->getIterator();
            StoreInst *SI = nullptr;
            for (;;) {
                SILInstruction *CI = &*II;
                if (CI == SEI)
                    break;
                ++II;
                SI = dyn_cast<StoreInst>(CI);
                if (SI) {
                    if (SI->getDest() == IEAI->getOperand())
                        return nullptr;
                }
                // Allow all instructions inbetween, which don't have any dependency to
//.........这里部分代码省略.........

/// \brief Returns the callee SILFunction called at a call site, in the case
/// that the call is transparent (as in, both that the call is marked
/// with the transparent flag and that callee function is actually transparently
/// determinable from the SIL) or nullptr otherwise. This assumes that the SIL
/// is already in SSA form.
///
/// In the case that a non-null value is returned, FullArgs contains effective
/// argument operands for the callee function.
static SILFunction *
getCalleeFunction(FullApplySite AI, bool &IsThick,
                  SmallVectorImpl<SILValue>& CaptureArgs,
                  SmallVectorImpl<SILValue>& FullArgs,
                  PartialApplyInst *&PartialApply,
                  SILModule::LinkingMode Mode) {
  IsThick = false;
  PartialApply = nullptr;
  CaptureArgs.clear();
  FullArgs.clear();

  for (const auto &Arg : AI.getArguments())
    FullArgs.push_back(Arg);
  SILValue CalleeValue = AI.getCallee();

  if (LoadInst *LI = dyn_cast<LoadInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);
    // Conservatively only see through alloc_box; we assume this pass is run
    // immediately after SILGen
    SILInstruction *ABI = dyn_cast<AllocBoxInst>(LI->getOperand());
    if (!ABI)
      return nullptr;
    assert(LI->getOperand().getResultNumber() == 1);

    // Scan forward from the alloc box to find the first store, which
    // (conservatively) must be in the same basic block as the alloc box
    StoreInst *SI = nullptr;
    for (auto I = SILBasicBlock::iterator(ABI), E = I->getParent()->end();
         I != E; ++I) {
      // If we find the load instruction first, then the load is loading from
      // a non-initialized alloc; this shouldn't really happen but I'm not
      // making any assumptions
      if (static_cast<SILInstruction*>(I) == LI)
        return nullptr;
      if ((SI = dyn_cast<StoreInst>(I)) && SI->getDest().getDef() == ABI) {
        // We found a store that we know dominates the load; now ensure there
        // are no other uses of the alloc other than loads, retains, releases
        // and dealloc stacks
        for (auto UI = ABI->use_begin(), UE = ABI->use_end(); UI != UE;
             ++UI)
          if (UI.getUser() != SI && !isa<LoadInst>(UI.getUser()) &&
              !isa<StrongRetainInst>(UI.getUser()) &&
              !isa<StrongReleaseInst>(UI.getUser()))
            return nullptr;
        // We can conservatively see through the store
        break;
      }
    }
    if (!SI)
      return nullptr;
    CalleeValue = SI->getSrc();
  }

  // We are allowed to see through exactly one "partial apply" instruction or
  // one "thin to thick function" instructions, since those are the patterns
  // generated when using auto closures.
  if (PartialApplyInst *PAI =
        dyn_cast<PartialApplyInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);

    for (const auto &Arg : PAI->getArguments()) {
      CaptureArgs.push_back(Arg);
      FullArgs.push_back(Arg);
    }

    CalleeValue = PAI->getCallee();
    IsThick = true;
    PartialApply = PAI;
  } else if (ThinToThickFunctionInst *TTTFI =
               dyn_cast<ThinToThickFunctionInst>(CalleeValue)) {
    assert(CalleeValue.getResultNumber() == 0);
    CalleeValue = TTTFI->getOperand();
    IsThick = true;
  }

  FunctionRefInst *FRI = dyn_cast<FunctionRefInst>(CalleeValue);

  if (!FRI)
    return nullptr;

  SILFunction *CalleeFunction = FRI->getReferencedFunction();

  switch (CalleeFunction->getRepresentation()) {
  case SILFunctionTypeRepresentation::Thick:
  case SILFunctionTypeRepresentation::Thin:
  case SILFunctionTypeRepresentation::Method:
  case SILFunctionTypeRepresentation::WitnessMethod:
    break;
    
  case SILFunctionTypeRepresentation::CFunctionPointer:
  case SILFunctionTypeRepresentation::ObjCMethod:
  case SILFunctionTypeRepresentation::Block:
//.........这里部分代码省略.........

/// Simplify the following two frontend patterns:
///
///   %payload_addr = init_enum_data_addr %payload_allocation
///   store %payload to %payload_addr
///   inject_enum_addr %payload_allocation, $EnumType.case
///
///   inject_enum_add %nopayload_allocation, $EnumType.case
///
/// for a concrete enum type $EnumType.case to:
///
///   %1 = enum $EnumType, $EnumType.case, %payload
///   store %1 to %payload_addr
///
///   %1 = enum $EnumType, $EnumType.case
///   store %1 to %nopayload_addr
///
/// We leave the cleaning up to mem2reg.
SILInstruction *
SILCombiner::visitInjectEnumAddrInst(InjectEnumAddrInst *IEAI) {
  // Given an inject_enum_addr of a concrete type without payload, promote it to
  // a store of an enum. Mem2reg/load forwarding will clean things up for us. We
  // can't handle the payload case here due to the flow problems caused by the
  // dependency in between the enum and its data.

  assert(IEAI->getOperand()->getType().isAddress() && "Must be an address");
  Builder.setCurrentDebugScope(IEAI->getDebugScope());

  if (IEAI->getOperand()->getType().isAddressOnly(IEAI->getModule())) {
    // Check for the following pattern inside the current basic block:
    // inject_enum_addr %payload_allocation, $EnumType.case1
    // ... no insns storing anything into %payload_allocation
    // select_enum_addr  %payload_allocation,
    //                   case $EnumType.case1: %Result1,
    //                   case case $EnumType.case2: %bResult2
    //                   ...
    //
    // Replace the select_enum_addr by %Result1

    auto *Term = IEAI->getParent()->getTerminator();
    if (isa<CondBranchInst>(Term) || isa<SwitchValueInst>(Term)) {
      auto BeforeTerm = std::prev(std::prev(IEAI->getParent()->end()));
      auto *SEAI = dyn_cast<SelectEnumAddrInst>(BeforeTerm);
      if (!SEAI)
        return nullptr;

      if (SEAI->getOperand() != IEAI->getOperand())
        return nullptr;

      SILBasicBlock::iterator II = IEAI->getIterator();
      StoreInst *SI = nullptr;
      for (;;) {
        SILInstruction *CI = &*II;
        if (CI == SEAI)
          break;
        ++II;
        SI = dyn_cast<StoreInst>(CI);
        if (SI) {
          if (SI->getDest() == IEAI->getOperand())
            return nullptr;
        }
        // Allow all instructions in between, which don't have any dependency to
        // the store.
        if (AA->mayWriteToMemory(&*II, IEAI->getOperand()))
          return nullptr;
      }

      auto *InjectedEnumElement = IEAI->getElement();
      auto Result = SEAI->getCaseResult(InjectedEnumElement);

      // Replace select_enum_addr by the result
      replaceInstUsesWith(*SEAI, Result);
      return nullptr;
    }

    // Check for the following pattern inside the current basic block:
    // inject_enum_addr %payload_allocation, $EnumType.case1
    // ... no insns storing anything into %payload_allocation
    // switch_enum_addr  %payload_allocation,
    //                   case $EnumType.case1: %bbX,
    //                   case case $EnumType.case2: %bbY
    //                   ...
    //
    // Replace the switch_enum_addr by select_enum_addr, switch_value.
    if (auto *SEI = dyn_cast<SwitchEnumAddrInst>(Term)) {
      if (SEI->getOperand() != IEAI->getOperand())
        return nullptr;

      SILBasicBlock::iterator II = IEAI->getIterator();
      StoreInst *SI = nullptr;
      for (;;) {
        SILInstruction *CI = &*II;
        if (CI == SEI)
          break;
        ++II;
        SI = dyn_cast<StoreInst>(CI);
        if (SI) {
          if (SI->getDest() == IEAI->getOperand())
            return nullptr;
        }
        // Allow all instructions in between, which don't have any dependency to
//.........这里部分代码省略.........