[Transforms] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

llvm/include/llvm/Transforms/IPO/Attributor.h

@@ -1348,7 +1348,7 @@ struct AttributorConfig {
   DenseSet<const char *> *Allowed = nullptr;
 
   /// Maximum number of iterations to run until fixpoint.
-  std::optional<unsigned> MaxFixpointIterations = None;
+  std::optional<unsigned> MaxFixpointIterations = std::nullopt;
 
   /// A callback function that returns an ORE object from a Function pointer.
   ///{
@@ -4392,7 +4392,7 @@ struct AAValueConstantRange
           AA::getWithType(*ConstantInt::get(Ty->getContext(), *C), *Ty));
     }
     if (RangeV.isEmptySet())
-      return llvm::None;
+      return std::nullopt;
     return nullptr;
   }
 
@@ -4647,7 +4647,7 @@ struct AAPotentialConstantValues
     if (getAssumedSet().size() == 0) {
       if (undefIsContained())
         return UndefValue::get(getAssociatedValue().getType());
-      return llvm::None;
+      return std::nullopt;
     }
 
     return nullptr;

llvm/include/llvm/Transforms/Scalar/GVN.h

@@ -72,11 +72,11 @@ class GVNLegacyPass;
 /// Intended use is to create a default object, modify parameters with
 /// additional setters and then pass it to GVN.
 struct GVNOptions {
-  std::optional<bool> AllowPRE = None;
+  std::optional<bool> AllowPRE = std::nullopt;
-  std::optional<bool> AllowLoadPRE = None;
+  std::optional<bool> AllowLoadPRE = std::nullopt;
-  std::optional<bool> AllowLoadInLoopPRE = None;
+  std::optional<bool> AllowLoadInLoopPRE = std::nullopt;
-  std::optional<bool> AllowLoadPRESplitBackedge = None;
+  std::optional<bool> AllowLoadPRESplitBackedge = std::nullopt;
-  std::optional<bool> AllowMemDep = None;
+  std::optional<bool> AllowMemDep = std::nullopt;
 
   GVNOptions() = default;
 

llvm/include/llvm/Transforms/Scalar/LoopPassManager.h

@@ -403,7 +403,7 @@ Optional<PreservedAnalyses> LoopPassManager::runSinglePass(
   // Check the PassInstrumentation's BeforePass callbacks before running the
   // pass, skip its execution completely if asked to (callback returns false).
   if (!PI.runBeforePass<Loop>(*Pass, L))
-    return None;
+    return std::nullopt;
 
   PreservedAnalyses PA = Pass->run(IR, AM, AR, U);
 

llvm/include/llvm/Transforms/Utils/BasicBlockUtils.h

@@ -574,12 +574,11 @@ bool SplitIndirectBrCriticalEdges(Function &F, bool IgnoreBlocksWithoutPHI,
 ///    for the caller to accomplish, since each specific use of this function
 ///    may have additional information which simplifies this fixup. For example,
 ///    see restoreSSA() in the UnifyLoopExits pass.
-BasicBlock *CreateControlFlowHub(DomTreeUpdater *DTU,
+BasicBlock *CreateControlFlowHub(
-    SmallVectorImpl<BasicBlock *> &GuardBlocks,
+    DomTreeUpdater *DTU, SmallVectorImpl<BasicBlock *> &GuardBlocks,
     const SetVector<BasicBlock *> &Predecessors,
-    const SetVector<BasicBlock *> &Successors,
+    const SetVector<BasicBlock *> &Successors, const StringRef Prefix,
-    const StringRef Prefix,
+    Optional<unsigned> MaxControlFlowBooleans = std::nullopt);
-    Optional<unsigned> MaxControlFlowBooleans = None);
 
 } // end namespace llvm
 

llvm/include/llvm/Transforms/Utils/SimplifyLibCalls.h

@@ -89,9 +89,9 @@ private:
   /// parameter. These are used by an implementation to opt-into stricter
   /// checking.
   bool isFortifiedCallFoldable(CallInst *CI, unsigned ObjSizeOp,
-                               Optional<unsigned> SizeOp = None,
+                               Optional<unsigned> SizeOp = std::nullopt,
-                               Optional<unsigned> StrOp = None,
+                               Optional<unsigned> StrOp = std::nullopt,
-                               Optional<unsigned> FlagsOp = None);
+                               Optional<unsigned> FlagsOp = std::nullopt);
 };
 
 /// LibCallSimplifier - This class implements a collection of optimizations

llvm/lib/Transforms/Coroutines/CoroElide.cpp

@@ -107,7 +107,7 @@ getFrameLayout(Function *Resume) {
   // Pull information from the function attributes.
   auto Size = Resume->getParamDereferenceableBytes(0);
   if (!Size)
-    return None;
+    return std::nullopt;
   return std::make_pair(Size, Resume->getParamAlign(0).valueOrOne());
 }
 

llvm/lib/Transforms/Coroutines/CoroFrame.cpp

@@ -892,7 +892,7 @@ static DIType *solveDIType(DIBuilder &Builder, Type *Ty,
     RetType =
         Builder.createPointerType(nullptr, Layout.getTypeSizeInBits(Ty),
                                   Layout.getABITypeAlignment(Ty) * CHAR_BIT,
-                                  /*DWARFAddressSpace=*/None, Name);
+                                  /*DWARFAddressSpace=*/std::nullopt, Name);
   } else if (Ty->isStructTy()) {
     auto *DIStruct = Builder.createStructType(
         Scope, Name, Scope->getFile(), LineNum, Layout.getTypeSizeInBits(Ty),
@@ -1149,8 +1149,8 @@ static StructType *buildFrameType(Function &F, coro::Shape &Shape,
 
     // Add header fields for the resume and destroy functions.
     // We can rely on these being perfectly packed.
-    (void)B.addField(FnPtrTy, None, /*header*/ true);
+    (void)B.addField(FnPtrTy, std::nullopt, /*header*/ true);
-    (void)B.addField(FnPtrTy, None, /*header*/ true);
+    (void)B.addField(FnPtrTy, std::nullopt, /*header*/ true);
 
     // PromiseAlloca field needs to be explicitly added here because it's
     // a header field with a fixed offset based on its alignment. Hence it
@@ -1164,7 +1164,7 @@ static StructType *buildFrameType(Function &F, coro::Shape &Shape,
     unsigned IndexBits = std::max(1U, Log2_64_Ceil(Shape.CoroSuspends.size()));
     Type *IndexType = Type::getIntNTy(C, IndexBits);
 
-    SwitchIndexFieldId = B.addField(IndexType, None);
+    SwitchIndexFieldId = B.addField(IndexType, std::nullopt);
   } else {
     assert(PromiseAlloca == nullptr && "lowering doesn't support promises");
   }
@@ -1189,8 +1189,8 @@ static StructType *buildFrameType(Function &F, coro::Shape &Shape,
     if (const Argument *A = dyn_cast<Argument>(S.first))
       if (A->hasByValAttr())
         FieldType = A->getParamByValType();
-    FieldIDType Id =
+    FieldIDType Id = B.addField(FieldType, std::nullopt, false /*header*/,
-        B.addField(FieldType, None, false /*header*/, true /*IsSpillOfValue*/);
+                                true /*IsSpillOfValue*/);
     FrameData.setFieldIndex(S.first, Id);
   }
 

llvm/lib/Transforms/IPO/ArgumentPromotion.cpp

@@ -489,7 +489,7 @@ static bool findArgParts(Argument *Arg, const DataLayout &DL, AAResults &AAR,
     Ptr = Ptr->stripAndAccumulateConstantOffsets(DL, Offset,
                                                  /* AllowNonInbounds */ true);
     if (Ptr != Arg)
-      return None;
+      return std::nullopt;
 
     if (Offset.getSignificantBits() >= 64)
       return false;

llvm/lib/Transforms/IPO/Attributor.cpp

@@ -1079,7 +1079,7 @@ Attributor::getAssumedConstant(const IRPosition &IRP,
   for (auto &CB : SimplificationCallbacks.lookup(IRP)) {
     Optional<Value *> SimplifiedV = CB(IRP, &AA, UsedAssumedInformation);
     if (!SimplifiedV)
-      return llvm::None;
+      return std::nullopt;
     if (isa_and_nonnull<Constant>(*SimplifiedV))
       return cast<Constant>(*SimplifiedV);
     return nullptr;
@@ -1091,7 +1091,7 @@ Attributor::getAssumedConstant(const IRPosition &IRP,
                                  AA::ValueScope::Interprocedural,
                                  UsedAssumedInformation)) {
     if (Values.empty())
-      return llvm::None;
+      return std::nullopt;
     if (auto *C = dyn_cast_or_null<Constant>(
             AAPotentialValues::getSingleValue(*this, AA, IRP, Values)))
       return C;
@@ -1113,7 +1113,7 @@ Optional<Value *> Attributor::getAssumedSimplified(const IRPosition &IRP,
   if (!getAssumedSimplifiedValues(IRP, AA, Values, S, UsedAssumedInformation))
     return &IRP.getAssociatedValue();
   if (Values.empty())
-    return llvm::None;
+    return std::nullopt;
   if (AA)
     if (Value *V = AAPotentialValues::getSingleValue(*this, *AA, IRP, Values))
       return V;

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

@@ -2861,7 +2861,7 @@ private:
         // If it is known (which we tested above) but it doesn't have a value,
         // then we can assume `undef` and hence the instruction is UB.
         KnownUBInsts.insert(I);
-        return llvm::None;
+        return std::nullopt;
       }
       if (!*SimplifiedV)
         return nullptr;
@@ -2869,7 +2869,7 @@ private:
     }
     if (isa<UndefValue>(V)) {
       KnownUBInsts.insert(I);
-      return llvm::None;
+      return std::nullopt;
     }
     return V;
   }
@@ -5534,7 +5534,7 @@ struct AAValueSimplifyImpl : AAValueSimplify {
     Optional<Constant *> COpt = AA.getAssumedConstant(A);
 
     if (!COpt) {
-      SimplifiedAssociatedValue = llvm::None;
+      SimplifiedAssociatedValue = std::nullopt;
       A.recordDependence(AA, *this, DepClassTy::OPTIONAL);
       return true;
     }
@@ -6091,7 +6091,7 @@ struct AAHeapToStackFunction final : public AAHeapToStack {
       if (!isa<UndefValue>(InitVal)) {
         IRBuilder<> Builder(Alloca->getNextNode());
         // TODO: Use alignment above if align!=1
-        Builder.CreateMemSet(Alloca, InitVal, Size, None);
+        Builder.CreateMemSet(Alloca, InitVal, Size, std::nullopt);
       }
       HasChanged = ChangeStatus::CHANGED;
     }
@@ -6108,7 +6108,7 @@ struct AAHeapToStackFunction final : public AAHeapToStack {
       return APInt(64, 0);
     if (auto *CI = dyn_cast_or_null<ConstantInt>(SimpleV.value()))
       return CI->getValue();
-    return llvm::None;
+    return std::nullopt;
   }
 
   Optional<APInt> getSize(Attributor &A, const AbstractAttribute &AA,
@@ -6439,7 +6439,7 @@ ChangeStatus AAHeapToStackFunction::updateImpl(Attributor &A) {
 namespace {
 struct AAPrivatizablePtrImpl : public AAPrivatizablePtr {
   AAPrivatizablePtrImpl(const IRPosition &IRP, Attributor &A)
-      : AAPrivatizablePtr(IRP, A), PrivatizableType(llvm::None) {}
+      : AAPrivatizablePtr(IRP, A), PrivatizableType(std::nullopt) {}
 
   ChangeStatus indicatePessimisticFixpoint() override {
     AAPrivatizablePtr::indicatePessimisticFixpoint();
@@ -9630,7 +9630,7 @@ private:
       if (Unreachable.count(&Fn))
         return false;
 
-      return llvm::None;
+      return std::nullopt;
     }
 
     /// Set of functions that we know for sure is reachable.
@@ -9909,7 +9909,7 @@ askForAssumedConstant(Attributor &A, const AbstractAttribute &QueryingAA,
 
   if (!COpt.has_value()) {
     A.recordDependence(AA, QueryingAA, DepClassTy::OPTIONAL);
-    return llvm::None;
+    return std::nullopt;
   }
   if (auto *C = COpt.value()) {
     A.recordDependence(AA, QueryingAA, DepClassTy::OPTIONAL);
@@ -9972,7 +9972,7 @@ struct AAPotentialValuesImpl : AAPotentialValues {
       return &IRP.getAssociatedValue();
     Optional<Constant *> C = askForAssumedConstant<AAType>(A, AA, IRP, Ty);
     if (!C)
-      return llvm::None;
+      return std::nullopt;
     if (C.value())
       if (auto *CC = AA::getWithType(**C, Ty))
         return CC;

llvm/lib/Transforms/IPO/GlobalOpt.cpp

@@ -883,7 +883,7 @@ OptimizeGlobalAddressOfAllocation(GlobalVariable *GV, CallInst *CI,
   if (!isa<UndefValue>(InitVal)) {
     IRBuilder<> Builder(CI->getNextNode());
     // TODO: Use alignment above if align!=1
-    Builder.CreateMemSet(NewGV, InitVal, AllocSize, None);
+    Builder.CreateMemSet(NewGV, InitVal, AllocSize, std::nullopt);
   }
 
   // Update users of the allocation to use the new global instead.

llvm/lib/Transforms/IPO/IROutliner.cpp

@@ -469,7 +469,7 @@ constantMatches(Value *V, unsigned GVN,
   // See if we have a constants
   Constant *CST = dyn_cast<Constant>(V);
   if (!CST)
-    return None;
+    return std::nullopt;
 
   // Holds a mapping from a global value number to a Constant.
   DenseMap<unsigned, Constant *>::iterator GVNToConstantIt;
@@ -684,7 +684,8 @@ Function *IROutliner::createFunction(Module &M, OutlinableGroup &Group,
         Unit /* Context */, F->getName(), MangledNameStream.str(),
         Unit /* File */,
         0 /* Line 0 is reserved for compiler-generated code. */,
-        DB.createSubroutineType(DB.getOrCreateTypeArray(None)), /* void type */
+        DB.createSubroutineType(
+            DB.getOrCreateTypeArray(std::nullopt)), /* void type */
         0, /* Line 0 is reserved for compiler-generated code. */
         DINode::DIFlags::FlagArtificial /* Compiler-generated code. */,
         /* Outlined code is optimized code by definition. */
@@ -1193,7 +1194,7 @@ static Optional<unsigned> getGVNForPHINode(OutlinableRegion &Region,
     Optional<unsigned> OGVN = Cand.getGVN(Incoming);
     if (!OGVN && Blocks.contains(IncomingBlock)) {
       Region.IgnoreRegion = true;
-      return None;
+      return std::nullopt;
     }
 
     // If the incoming block isn't in the region, we don't have to worry about
@@ -2013,7 +2014,7 @@ Optional<unsigned> findDuplicateOutputBlock(
     MatchingNum++;
   }
 
-  return None;
+  return std::nullopt;
 }
 
 /// Remove empty output blocks from the outlined region.

llvm/lib/Transforms/IPO/OpenMPOpt.cpp

@@ -2342,7 +2342,7 @@ struct AAICVTracker : public StateWrapper<BooleanState, AbstractAttribute> {
   virtual Optional<Value *> getReplacementValue(InternalControlVar ICV,
                                                 const Instruction *I,
                                                 Attributor &A) const {
-    return None;
+    return std::nullopt;
   }
 
   /// Return an assumed unique ICV value if a single candidate is found. If
@@ -2447,7 +2447,7 @@ struct AAICVTrackerFunction : public AAICVTracker {
     const auto *CB = dyn_cast<CallBase>(&I);
     if (!CB || CB->hasFnAttr("no_openmp") ||
         CB->hasFnAttr("no_openmp_routines"))
-      return None;
+      return std::nullopt;
 
     auto &OMPInfoCache = static_cast<OMPInformationCache &>(A.getInfoCache());
     auto &GetterRFI = OMPInfoCache.RFIs[OMPInfoCache.ICVs[ICV].Getter];
@@ -2458,7 +2458,7 @@ struct AAICVTrackerFunction : public AAICVTracker {
     if (CalledFunction == nullptr)
       return nullptr;
     if (CalledFunction == GetterRFI.Declaration)
-      return None;
+      return std::nullopt;
     if (CalledFunction == SetterRFI.Declaration) {
       if (ICVReplacementValuesMap[ICV].count(&I))
         return ICVReplacementValuesMap[ICV].lookup(&I);
@@ -2487,7 +2487,7 @@ struct AAICVTrackerFunction : public AAICVTracker {
   // We don't check unique value for a function, so return None.
   Optional<Value *>
   getUniqueReplacementValue(InternalControlVar ICV) const override {
-    return None;
+    return std::nullopt;
   }
 
   /// Return the value with which \p I can be replaced for specific \p ICV.

llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp

@@ -814,8 +814,8 @@ void updatePublicTypeTestCalls(Module &M,
     for (Use &U : make_early_inc_range(PublicTypeTestFunc->uses())) {
       auto *CI = cast<CallInst>(U.getUser());
       auto *NewCI = CallInst::Create(
-          TypeTestFunc, {CI->getArgOperand(0), CI->getArgOperand(1)}, None, "",
+          TypeTestFunc, {CI->getArgOperand(0), CI->getArgOperand(1)},
-          CI);
+          std::nullopt, "", CI);
       CI->replaceAllUsesWith(NewCI);
       CI->eraseFromParent();
     }

llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

@@ -243,7 +243,7 @@ getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C,
   // Don't allow pointers. Splat vectors are fine.
   if (!LHS->getOperand(0)->getType()->isIntOrIntVectorTy() ||
       !RHS->getOperand(0)->getType()->isIntOrIntVectorTy())
-    return None;
+    return std::nullopt;
 
   // Here comes the tricky part:
   // LHS might be of the form L11 & L12 == X, X == L21 & L22,
@@ -274,7 +274,7 @@ getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C,
 
   // Bail if LHS was a icmp that can't be decomposed into an equality.
   if (!ICmpInst::isEquality(PredL))
-    return None;
+    return std::nullopt;
 
   Value *R1 = RHS->getOperand(0);
   Value *R2 = RHS->getOperand(1);
@@ -288,7 +288,7 @@ getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C,
       A = R12;
       D = R11;
     } else {
-      return None;
+      return std::nullopt;
     }
     E = R2;
     R1 = nullptr;
@@ -316,7 +316,7 @@ getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C,
 
   // Bail if RHS was a icmp that can't be decomposed into an equality.
   if (!ICmpInst::isEquality(PredR))
-    return None;
+    return std::nullopt;
 
   // Look for ANDs on the right side of the RHS icmp.
   if (!Ok) {
@@ -336,7 +336,7 @@ getMaskedTypeForICmpPair(Value *&A, Value *&B, Value *&C,
       E = R1;
       Ok = true;
     } else {
-      return None;
+      return std::nullopt;
     }
 
     assert(Ok && "Failed to find AND on the right side of the RHS icmp.");
@@ -1019,7 +1019,7 @@ struct IntPart {
 static Optional<IntPart> matchIntPart(Value *V) {
   Value *X;
   if (!match(V, m_OneUse(m_Trunc(m_Value(X)))))
-    return None;
+    return std::nullopt;
 
   unsigned NumOriginalBits = X->getType()->getScalarSizeInBits();
   unsigned NumExtractedBits = V->getType()->getScalarSizeInBits();

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

@@ -2346,7 +2346,7 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
         Pred == ICmpInst::ICMP_NE && LHS->getOpcode() == Instruction::Load &&
         LHS->getType()->isPointerTy() &&
         isValidAssumeForContext(II, LHS, &DT)) {
-      MDNode *MD = MDNode::get(II->getContext(), None);
+      MDNode *MD = MDNode::get(II->getContext(), std::nullopt);
       LHS->setMetadata(LLVMContext::MD_nonnull, MD);
       return RemoveConditionFromAssume(II);
 

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -5873,13 +5873,13 @@ InstCombiner::getFlippedStrictnessPredicateAndConstant(CmpInst::Predicate Pred,
   if (auto *CI = dyn_cast<ConstantInt>(C)) {
     // Bail out if the constant can't be safely incremented/decremented.
     if (!ConstantIsOk(CI))
-      return llvm::None;
+      return std::nullopt;
   } else if (auto *FVTy = dyn_cast<FixedVectorType>(Type)) {
     unsigned NumElts = FVTy->getNumElements();
     for (unsigned i = 0; i != NumElts; ++i) {
       Constant *Elt = C->getAggregateElement(i);
       if (!Elt)
-        return llvm::None;
+        return std::nullopt;
 
       if (isa<UndefValue>(Elt))
         continue;
@@ -5888,14 +5888,14 @@ InstCombiner::getFlippedStrictnessPredicateAndConstant(CmpInst::Predicate Pred,
       // know that this constant is min/max.
       auto *CI = dyn_cast<ConstantInt>(Elt);
       if (!CI || !ConstantIsOk(CI))
-        return llvm::None;
+        return std::nullopt;
 
       if (!SafeReplacementConstant)
         SafeReplacementConstant = CI;
     }
   } else {
     // ConstantExpr?
-    return llvm::None;
+    return std::nullopt;
   }
 
   // It may not be safe to change a compare predicate in the presence of

llvm/lib/Transforms/InstCombine/InstCombineNegator.cpp

@@ -522,7 +522,7 @@ std::array<Value *, 2> Negator::getSortedOperandsOfBinOp(Instruction *I) {
     // endless combine looping.
     for (Instruction *I : llvm::reverse(NewInstructions))
       I->eraseFromParent();
-    return llvm::None;
+    return std::nullopt;
   }
   return std::make_pair(ArrayRef<Instruction *>(NewInstructions), Negated);
 }

llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp

@@ -871,7 +871,7 @@ Instruction *InstCombinerImpl::foldAggregateConstructionIntoAggregateReuse(
   if (NumAggElts > 2)
     return nullptr;
 
-  static constexpr auto NotFound = None;
+  static constexpr auto NotFound = std::nullopt;
   static constexpr auto FoundMismatch = nullptr;
 
   // Try to find a value of each element of an aggregate.
@@ -1032,7 +1032,8 @@ Instruction *InstCombinerImpl::foldAggregateConstructionIntoAggregateReuse(
   Optional<Value *> SourceAggregate;
 
   // Can we find the source aggregate without looking at predecessors?
-  SourceAggregate = FindCommonSourceAggregate(/*UseBB=*/None, /*PredBB=*/None);
+  SourceAggregate = FindCommonSourceAggregate(/*UseBB=*/std::nullopt,
+                                              /*PredBB=*/std::nullopt);
   if (Describe(SourceAggregate) != AggregateDescription::NotFound) {
     if (Describe(SourceAggregate) == AggregateDescription::FoundMismatch)
       return nullptr; // Conflicting source aggregates!

llvm/lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -2888,7 +2888,7 @@ Instruction *InstCombinerImpl::visitAllocSite(Instruction &MI) {
       Module *M = II->getModule();
       Function *F = Intrinsic::getDeclaration(M, Intrinsic::donothing);
       InvokeInst::Create(F, II->getNormalDest(), II->getUnwindDest(),
-                         None, "", II->getParent());
+                         std::nullopt, "", II->getParent());
     }
 
     // Remove debug intrinsics which describe the value contained within the
@@ -4214,7 +4214,7 @@ bool InstCombinerImpl::run() {
     auto getOptionalSinkBlockForInst =
         [this](Instruction *I) -> std::optional<BasicBlock *> {
       if (!EnableCodeSinking)
-        return None;
+        return std::nullopt;
 
       BasicBlock *BB = I->getParent();
       BasicBlock *UserParent = nullptr;
@@ -4224,7 +4224,7 @@ bool InstCombinerImpl::run() {
         if (U->isDroppable())
           continue;
         if (NumUsers > MaxSinkNumUsers)
-          return None;
+          return std::nullopt;
 
         Instruction *UserInst = cast<Instruction>(U);
         // Special handling for Phi nodes - get the block the use occurs in.
@@ -4235,14 +4235,14 @@ bool InstCombinerImpl::run() {
               // sophisticated analysis (i.e finding NearestCommonDominator of
               // these use blocks).
               if (UserParent && UserParent != PN->getIncomingBlock(i))
-                return None;
+                return std::nullopt;
               UserParent = PN->getIncomingBlock(i);
             }
           }
           assert(UserParent && "expected to find user block!");
         } else {
           if (UserParent && UserParent != UserInst->getParent())
-            return None;
+            return std::nullopt;
           UserParent = UserInst->getParent();
         }
 
@@ -4252,7 +4252,7 @@ bool InstCombinerImpl::run() {
           // Try sinking to another block. If that block is unreachable, then do
           // not bother. SimplifyCFG should handle it.
           if (UserParent == BB || !DT.isReachableFromEntry(UserParent))
-            return None;
+            return std::nullopt;
 
           auto *Term = UserParent->getTerminator();
           // See if the user is one of our successors that has only one
@@ -4264,7 +4264,7 @@ bool InstCombinerImpl::run() {
           //   - the User will be executed at most once.
           // So sinking I down to User is always profitable or neutral.
           if (UserParent->getUniquePredecessor() != BB && !succ_empty(Term))
-            return None;
+            return std::nullopt;
 
           assert(DT.dominates(BB, UserParent) && "Dominance relation broken?");
         }
@@ -4274,7 +4274,7 @@ bool InstCombinerImpl::run() {
 
       // No user or only has droppable users.
       if (!UserParent)
-        return None;
+        return std::nullopt;
 
       return UserParent;
     };

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

@@ -1305,12 +1305,13 @@ void AddressSanitizer::getInterestingMemoryOperands(
     if (!ClInstrumentAtomics || ignoreAccess(I, RMW->getPointerOperand()))
       return;
     Interesting.emplace_back(I, RMW->getPointerOperandIndex(), true,
-                             RMW->getValOperand()->getType(), None);
+                             RMW->getValOperand()->getType(), std::nullopt);
   } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
     if (!ClInstrumentAtomics || ignoreAccess(I, XCHG->getPointerOperand()))
       return;
     Interesting.emplace_back(I, XCHG->getPointerOperandIndex(), true,
-                             XCHG->getCompareOperand()->getType(), None);
+                             XCHG->getCompareOperand()->getType(),
+                             std::nullopt);
   } else if (auto CI = dyn_cast<CallInst>(I)) {
     if (CI->getIntrinsicID() == Intrinsic::masked_load ||
         CI->getIntrinsicID() == Intrinsic::masked_store) {

llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp

@@ -1087,8 +1087,8 @@ bool DataFlowSanitizer::initializeModule(Module &M) {
                                 Type::getInt8PtrTy(*Ctx), IntptrTy};
   DFSanSetLabelFnTy = FunctionType::get(Type::getVoidTy(*Ctx),
                                         DFSanSetLabelArgs, /*isVarArg=*/false);
-  DFSanNonzeroLabelFnTy =
+  DFSanNonzeroLabelFnTy = FunctionType::get(Type::getVoidTy(*Ctx), std::nullopt,
-      FunctionType::get(Type::getVoidTy(*Ctx), None, /*isVarArg=*/false);
+                                            /*isVarArg=*/false);
   DFSanVarargWrapperFnTy = FunctionType::get(
       Type::getVoidTy(*Ctx), Type::getInt8PtrTy(*Ctx), /*isVarArg=*/false);
   DFSanConditionalCallbackFnTy =

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

@@ -757,12 +757,13 @@ void HWAddressSanitizer::getInterestingMemoryOperands(
     if (!ClInstrumentAtomics || ignoreAccess(I, RMW->getPointerOperand()))
       return;
     Interesting.emplace_back(I, RMW->getPointerOperandIndex(), true,
-                             RMW->getValOperand()->getType(), None);
+                             RMW->getValOperand()->getType(), std::nullopt);
   } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
     if (!ClInstrumentAtomics || ignoreAccess(I, XCHG->getPointerOperand()))
       return;
     Interesting.emplace_back(I, XCHG->getPointerOperandIndex(), true,
-                             XCHG->getCompareOperand()->getType(), None);
+                             XCHG->getCompareOperand()->getType(),
+                             std::nullopt);
   } else if (auto CI = dyn_cast<CallInst>(I)) {
     for (unsigned ArgNo = 0; ArgNo < CI->arg_size(); ArgNo++) {
       if (!ClInstrumentByval || !CI->isByValArgument(ArgNo) ||

llvm/lib/Transforms/Instrumentation/MemProfiler.cpp

@@ -271,31 +271,31 @@ Optional<InterestingMemoryAccess>
 MemProfiler::isInterestingMemoryAccess(Instruction *I) const {
   // Do not instrument the load fetching the dynamic shadow address.
   if (DynamicShadowOffset == I)
-    return None;
+    return std::nullopt;
 
   InterestingMemoryAccess Access;
 
   if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
     if (!ClInstrumentReads)
-      return None;
+      return std::nullopt;
     Access.IsWrite = false;
     Access.AccessTy = LI->getType();
     Access.Addr = LI->getPointerOperand();
   } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
     if (!ClInstrumentWrites)
-      return None;
+      return std::nullopt;
     Access.IsWrite = true;
     Access.AccessTy = SI->getValueOperand()->getType();
     Access.Addr = SI->getPointerOperand();
   } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
     if (!ClInstrumentAtomics)
-      return None;
+      return std::nullopt;
     Access.IsWrite = true;
     Access.AccessTy = RMW->getValOperand()->getType();
     Access.Addr = RMW->getPointerOperand();
   } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
     if (!ClInstrumentAtomics)
-      return None;
+      return std::nullopt;
     Access.IsWrite = true;
     Access.AccessTy = XCHG->getCompareOperand()->getType();
     Access.Addr = XCHG->getPointerOperand();
@@ -306,14 +306,14 @@ MemProfiler::isInterestingMemoryAccess(Instruction *I) const {
       unsigned OpOffset = 0;
       if (F->getIntrinsicID() == Intrinsic::masked_store) {
         if (!ClInstrumentWrites)
-          return None;
+          return std::nullopt;
         // Masked store has an initial operand for the value.
         OpOffset = 1;
         Access.AccessTy = CI->getArgOperand(0)->getType();
         Access.IsWrite = true;
       } else {
         if (!ClInstrumentReads)
-          return None;
+          return std::nullopt;
         Access.AccessTy = CI->getType();
         Access.IsWrite = false;
       }
@@ -325,20 +325,20 @@ MemProfiler::isInterestingMemoryAccess(Instruction *I) const {
   }
 
   if (!Access.Addr)
-    return None;
+    return std::nullopt;
 
   // Do not instrument accesses from different address spaces; we cannot deal
   // with them.
   Type *PtrTy = cast<PointerType>(Access.Addr->getType()->getScalarType());
   if (PtrTy->getPointerAddressSpace() != 0)
-    return None;
+    return std::nullopt;
 
   // Ignore swifterror addresses.
   // swifterror memory addresses are mem2reg promoted by instruction
   // selection. As such they cannot have regular uses like an instrumentation
   // function and it makes no sense to track them as memory.
   if (Access.Addr->isSwiftError())
-    return None;
+    return std::nullopt;
 
   // Peel off GEPs and BitCasts.
   auto *Addr = Access.Addr->stripInBoundsOffsets();
@@ -351,12 +351,12 @@ MemProfiler::isInterestingMemoryAccess(Instruction *I) const {
       auto OF = Triple(I->getModule()->getTargetTriple()).getObjectFormat();
       if (SectionName.endswith(
               getInstrProfSectionName(IPSK_cnts, OF, /*AddSegmentInfo=*/false)))
-        return None;
+        return std::nullopt;
     }
 
     // Do not instrument accesses to LLVM internal variables.
     if (GV->getName().startswith("__llvm"))
-      return None;
+      return std::nullopt;
   }
 
   const DataLayout &DL = I->getModule()->getDataLayout();

llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp

@@ -4128,7 +4128,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
           if (ArgOffset + Size > kParamTLSSize)
             break;
           const MaybeAlign ParamAlignment(CB.getParamAlign(i));
-          MaybeAlign Alignment = llvm::None;
+          MaybeAlign Alignment = std::nullopt;
           if (ParamAlignment)
             Alignment = std::min(*ParamAlignment, kShadowTLSAlignment);
           Value *AShadowPtr, *AOriginPtr;

llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp

@@ -251,7 +251,7 @@ private:
                                                 Type *Ty);
 
   void SetNoSanitizeMetadata(Instruction *I) {
-    I->setMetadata(LLVMContext::MD_nosanitize, MDNode::get(*C, None));
+    I->setMetadata(LLVMContext::MD_nosanitize, MDNode::get(*C, std::nullopt));
   }
 
   std::string getSectionName(const std::string &Section) const;

llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp

@@ -472,7 +472,8 @@ bool ObjCARCContract::tryToPeepholeInstruction(
                          RVInstMarker->getString(),
                          /*Constraints=*/"", /*hasSideEffects=*/true);
 
-      objcarc::createCallInstWithColors(IA, None, "", Inst, BlockColors);
+      objcarc::createCallInstWithColors(IA, std::nullopt, "", Inst,
+                                        BlockColors);
     }
   decline_rv_optimization:
     return false;

llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp

@@ -999,7 +999,7 @@ void ObjCARCOpt::OptimizeIndividualCallImpl(
       CallInst *NewCall =
           CallInst::Create(Decl, Call->getArgOperand(0), "", Call);
       NewCall->setMetadata(MDKindCache.get(ARCMDKindID::ImpreciseRelease),
-                           MDNode::get(C, None));
+                           MDNode::get(C, std::nullopt));
 
       LLVM_DEBUG(dbgs() << "Replacing autorelease{,RV}(x) with objc_release(x) "
                            "since x is otherwise unused.\nOld: "

llvm/lib/Transforms/Scalar/AlignmentFromAssumptions.cpp

@@ -116,7 +116,7 @@ static MaybeAlign getNewAlignmentDiff(const SCEV *DiffSCEV,
       return Align(DiffUnitsAbs);
   }
 
-  return None;
+  return std::nullopt;
 }
 
 // There is an address given by an offset OffSCEV from AASCEV which has an

llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp

@@ -497,8 +497,8 @@ static void shortenAssignment(Instruction *Inst, uint64_t OldOffsetInBits,
     // FIXME: This should be using the DIExpression in the Alloca's dbg.assign
     // for the variable, since that could also contain a fragment?
     return *DIExpression::createFragmentExpression(
-        DIExpression::get(Inst->getContext(), None), DeadFragment.OffsetInBits,
+        DIExpression::get(Inst->getContext(), std::nullopt),
-        DeadFragment.SizeInBits);
+        DeadFragment.OffsetInBits, DeadFragment.SizeInBits);
   };
 
   // A DIAssignID to use so that the inserted dbg.assign intrinsics do not
@@ -1303,7 +1303,7 @@ struct DSEState {
                   bool IsMemTerm, unsigned &PartialLimit) {
     if (ScanLimit == 0 || WalkerStepLimit == 0) {
       LLVM_DEBUG(dbgs() << "\n    ...  hit scan limit\n");
-      return None;
+      return std::nullopt;
     }
 
     MemoryAccess *Current = StartAccess;
@@ -1336,7 +1336,7 @@ struct DSEState {
         if (CanOptimize && Current != KillingDef->getDefiningAccess())
           // The first clobbering def is... none.
           KillingDef->setOptimized(Current);
-        return None;
+        return std::nullopt;
       }
 
       // Cost of a step. Accesses in the same block are more likely to be valid
@@ -1346,7 +1346,7 @@ struct DSEState {
                               : MemorySSAOtherBBStepCost;
       if (WalkerStepLimit <= StepCost) {
         LLVM_DEBUG(dbgs() << "   ...  hit walker step limit\n");
-        return None;
+        return std::nullopt;
       }
       WalkerStepLimit -= StepCost;
 
@@ -1371,14 +1371,14 @@ struct DSEState {
       // instructions that block us from DSEing
       if (mayThrowBetween(KillingI, CurrentI, KillingUndObj)) {
         LLVM_DEBUG(dbgs() << "  ... skip, may throw!\n");
-        return None;
+        return std::nullopt;
       }
 
       // Check for anything that looks like it will be a barrier to further
       // removal
       if (isDSEBarrier(KillingUndObj, CurrentI)) {
         LLVM_DEBUG(dbgs() << "  ... skip, barrier\n");
-        return None;
+        return std::nullopt;
       }
 
       // If Current is known to be on path that reads DefLoc or is a read
@@ -1386,7 +1386,7 @@ struct DSEState {
       // for intrinsic calls, because the code knows how to handle memcpy
       // intrinsics.
       if (!isa<IntrinsicInst>(CurrentI) && isReadClobber(KillingLoc, CurrentI))
-        return None;
+        return std::nullopt;
 
       // Quick check if there are direct uses that are read-clobbers.
       if (any_of(Current->uses(), [this, &KillingLoc, StartAccess](Use &U) {
@@ -1396,7 +1396,7 @@ struct DSEState {
             return false;
           })) {
         LLVM_DEBUG(dbgs() << "   ...  found a read clobber\n");
-        return None;
+        return std::nullopt;
       }
 
       // If Current does not have an analyzable write location or is not
@@ -1490,7 +1490,7 @@ struct DSEState {
       // Bail out if the number of accesses to check exceeds the scan limit.
       if (ScanLimit < (WorkList.size() - I)) {
         LLVM_DEBUG(dbgs() << "\n    ...  hit scan limit\n");
-        return None;
+        return std::nullopt;
       }
       --ScanLimit;
       NumDomMemDefChecks++;
@@ -1535,14 +1535,14 @@ struct DSEState {
 
       if (UseInst->mayThrow() && !isInvisibleToCallerOnUnwind(KillingUndObj)) {
         LLVM_DEBUG(dbgs() << "  ... found throwing instruction\n");
-        return None;
+        return std::nullopt;
       }
 
       // Uses which may read the original MemoryDef mean we cannot eliminate the
       // original MD. Stop walk.
       if (isReadClobber(MaybeDeadLoc, UseInst)) {
         LLVM_DEBUG(dbgs() << "    ... found read clobber\n");
-        return None;
+        return std::nullopt;
       }
 
       // If this worklist walks back to the original memory access (and the
@@ -1551,7 +1551,7 @@ struct DSEState {
       if (MaybeDeadAccess == UseAccess &&
           !isGuaranteedLoopInvariant(MaybeDeadLoc.Ptr)) {
         LLVM_DEBUG(dbgs() << "    ... found not loop invariant self access\n");
-        return None;
+        return std::nullopt;
       }
       // Otherwise, for the KillingDef and MaybeDeadAccess we only have to check
       // if it reads the memory location.
@@ -1585,7 +1585,7 @@ struct DSEState {
           } else {
             LLVM_DEBUG(dbgs()
                        << "    ... found preceeding def " << *UseInst << "\n");
-            return None;
+            return std::nullopt;
           }
         } else
           PushMemUses(UseDef);
@@ -1615,7 +1615,7 @@ struct DSEState {
       // killing block.
       if (!PDT.dominates(CommonPred, MaybeDeadAccess->getBlock())) {
         if (!AnyUnreachableExit)
-          return None;
+          return std::nullopt;
 
         // Fall back to CFG scan starting at all non-unreachable roots if not
         // all paths to the exit go through CommonPred.
@@ -1646,7 +1646,7 @@ struct DSEState {
         if (KillingBlocks.count(Current))
           continue;
         if (Current == MaybeDeadAccess->getBlock())
-          return None;
+          return std::nullopt;
 
         // MaybeDeadAccess is reachable from the entry, so we don't have to
         // explore unreachable blocks further.
@@ -1657,7 +1657,7 @@ struct DSEState {
           WorkList.insert(Pred);
 
         if (WorkList.size() >= MemorySSAPathCheckLimit)
-          return None;
+          return std::nullopt;
       }
       NumCFGSuccess++;
     }

llvm/lib/Transforms/Scalar/Float2Int.cpp

@@ -243,7 +243,7 @@ Optional<ConstantRange> Float2IntPass::calcRange(Instruction *I) {
       auto OpIt = SeenInsts.find(OI);
       assert(OpIt != SeenInsts.end() && "def not seen before use!");
       if (OpIt->second == unknownRange())
-        return None; // Wait until operand range has been calculated.
+        return std::nullopt; // Wait until operand range has been calculated.
       OpRanges.push_back(OpIt->second);
     } else if (ConstantFP *CF = dyn_cast<ConstantFP>(O)) {
       // Work out if the floating point number can be losslessly represented

llvm/lib/Transforms/Scalar/GVN.cpp

@@ -763,14 +763,14 @@ void GVNPass::printPipeline(
       OS, MapClassName2PassName);
 
   OS << "<";
-  if (Options.AllowPRE != None)
+  if (Options.AllowPRE != std::nullopt)
     OS << (Options.AllowPRE.value() ? "" : "no-") << "pre;";
-  if (Options.AllowLoadPRE != None)
+  if (Options.AllowLoadPRE != std::nullopt)
     OS << (Options.AllowLoadPRE.value() ? "" : "no-") << "load-pre;";
-  if (Options.AllowLoadPRESplitBackedge != None)
+  if (Options.AllowLoadPRESplitBackedge != std::nullopt)
     OS << (Options.AllowLoadPRESplitBackedge.value() ? "" : "no-")
        << "split-backedge-load-pre;";
-  if (Options.AllowMemDep != None)
+  if (Options.AllowMemDep != std::nullopt)
     OS << (Options.AllowMemDep.value() ? "" : "no-") << "memdep";
   OS << ">";
 }
@@ -1129,12 +1129,12 @@ tryToConvertLoadOfPtrSelect(BasicBlock *DepBB, BasicBlock::iterator End,
 
   auto *Sel = dyn_cast_or_null<SelectInst>(Address);
   if (!Sel || DepBB != Sel->getParent())
-    return None;
+    return std::nullopt;
 
   LoadInst *L1 = findDominatingLoad(Sel->getOperand(1), LoadTy, Sel, DT);
   LoadInst *L2 = findDominatingLoad(Sel->getOperand(2), LoadTy, Sel, DT);
   if (!L1 || !L2)
-    return None;
+    return std::nullopt;
 
   // Ensure there are no accesses that may modify the locations referenced by
   // either L1 or L2 between L1, L2 and the specified End iterator.
@@ -1145,7 +1145,7 @@ tryToConvertLoadOfPtrSelect(BasicBlock *DepBB, BasicBlock::iterator End,
         return isModSet(AA->getModRefInfo(&I, L1Loc)) ||
                isModSet(AA->getModRefInfo(&I, L2Loc));
       }))
-    return None;
+    return std::nullopt;
 
   return AvailableValue::getSelect(Sel);
 }
@@ -1204,7 +1204,9 @@ bool GVNPass::AnalyzeLoadAvailability(LoadInst *Load, MemDepResult DepInfo,
             canCoerceMustAliasedValueToLoad(DepLoad, LoadType, DL)) {
           const auto ClobberOff = MD->getClobberOffset(DepLoad);
           // GVN has no deal with a negative offset.
-          Offset = (ClobberOff == None || *ClobberOff < 0) ? -1 : *ClobberOff;
+          Offset = (ClobberOff == std::nullopt || *ClobberOff < 0)
+                       ? -1
+                       : *ClobberOff;
         }
         if (Offset == -1)
           Offset =

llvm/lib/Transforms/Scalar/GVNSink.cpp

@@ -654,7 +654,7 @@ Optional<SinkingInstructionCandidate> GVNSink::analyzeInstructionForSinking(
     uint32_t N = VN.lookupOrAdd(I);
     LLVM_DEBUG(dbgs() << " VN=" << Twine::utohexstr(N) << " for" << *I << "\n");
     if (N == ~0U)
-      return None;
+      return std::nullopt;
     VNums[N]++;
   }
   unsigned VNumToSink =
@@ -662,7 +662,7 @@ Optional<SinkingInstructionCandidate> GVNSink::analyzeInstructionForSinking(
 
   if (VNums[VNumToSink] == 1)
     // Can't sink anything!
-    return None;
+    return std::nullopt;
 
   // Now restrict the number of incoming blocks down to only those with
   // VNumToSink.
@@ -677,7 +677,7 @@ Optional<SinkingInstructionCandidate> GVNSink::analyzeInstructionForSinking(
   }
   for (auto *I : NewInsts)
     if (shouldAvoidSinkingInstruction(I))
-      return None;
+      return std::nullopt;
 
   // If we've restricted the incoming blocks, restrict all needed PHIs also
   // to that set.
@@ -715,7 +715,7 @@ Optional<SinkingInstructionCandidate> GVNSink::analyzeInstructionForSinking(
       // V exists in this PHI, but the whole PHI is different to NewPHI
       // (else it would have been removed earlier). We cannot continue
       // because this isn't representable.
-      return None;
+      return std::nullopt;
 
   // Which operands need PHIs?
   // FIXME: If any of these fail, we should partition up the candidates to
@@ -728,7 +728,7 @@ Optional<SinkingInstructionCandidate> GVNSink::analyzeInstructionForSinking(
     return I->getNumOperands() != I0->getNumOperands();
   };
   if (any_of(NewInsts, hasDifferentNumOperands))
-    return None;
+    return std::nullopt;
 
   for (unsigned OpNum = 0, E = I0->getNumOperands(); OpNum != E; ++OpNum) {
     ModelledPHI PHI(NewInsts, OpNum, ActivePreds);
@@ -736,15 +736,15 @@ Optional<SinkingInstructionCandidate> GVNSink::analyzeInstructionForSinking(
       continue;
     if (!canReplaceOperandWithVariable(I0, OpNum))
       // We can 't create a PHI from this instruction!
-      return None;
+      return std::nullopt;
     if (NeededPHIs.count(PHI))
       continue;
     if (!PHI.areAllIncomingValuesSameType())
-      return None;
+      return std::nullopt;
     // Don't create indirect calls! The called value is the final operand.
     if ((isa<CallInst>(I0) || isa<InvokeInst>(I0)) && OpNum == E - 1 &&
         PHI.areAnyIncomingValuesConstant())
-      return None;
+      return std::nullopt;
 
     NeededPHIs.reserve(NeededPHIs.size());
     NeededPHIs.insert(PHI);

llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp

@@ -246,7 +246,7 @@ class InductiveRangeCheckElimination {
 public:
   InductiveRangeCheckElimination(ScalarEvolution &SE,
                                  BranchProbabilityInfo *BPI, DominatorTree &DT,
-                                 LoopInfo &LI, GetBFIFunc GetBFI = None)
+                                 LoopInfo &LI, GetBFIFunc GetBFI = std::nullopt)
       : SE(SE), BPI(BPI), DT(DT), LI(LI), GetBFI(GetBFI) {}
 
   bool run(Loop *L, function_ref<void(Loop *, bool)> LPMAddNewLoop);
@@ -753,7 +753,7 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
                                   const char *&FailureReason) {
   if (!L.isLoopSimplifyForm()) {
     FailureReason = "loop not in LoopSimplify form";
-    return None;
+    return std::nullopt;
   }
 
   BasicBlock *Latch = L.getLoopLatch();
@@ -761,25 +761,25 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
 
   if (Latch->getTerminator()->getMetadata(ClonedLoopTag)) {
     FailureReason = "loop has already been cloned";
-    return None;
+    return std::nullopt;
   }
 
   if (!L.isLoopExiting(Latch)) {
     FailureReason = "no loop latch";
-    return None;
+    return std::nullopt;
   }
 
   BasicBlock *Header = L.getHeader();
   BasicBlock *Preheader = L.getLoopPreheader();
   if (!Preheader) {
     FailureReason = "no preheader";
-    return None;
+    return std::nullopt;
   }
 
   BranchInst *LatchBr = dyn_cast<BranchInst>(Latch->getTerminator());
   if (!LatchBr || LatchBr->isUnconditional()) {
     FailureReason = "latch terminator not conditional branch";
-    return None;
+    return std::nullopt;
   }
 
   unsigned LatchBrExitIdx = LatchBr->getSuccessor(0) == Header ? 1 : 0;
@@ -787,13 +787,13 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
   ICmpInst *ICI = dyn_cast<ICmpInst>(LatchBr->getCondition());
   if (!ICI || !isa<IntegerType>(ICI->getOperand(0)->getType())) {
     FailureReason = "latch terminator branch not conditional on integral icmp";
-    return None;
+    return std::nullopt;
   }
 
   const SCEV *LatchCount = SE.getExitCount(&L, Latch);
   if (isa<SCEVCouldNotCompute>(LatchCount)) {
     FailureReason = "could not compute latch count";
-    return None;
+    return std::nullopt;
   }
 
   ICmpInst::Predicate Pred = ICI->getPredicate();
@@ -812,7 +812,7 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
       Pred = ICmpInst::getSwappedPredicate(Pred);
     } else {
       FailureReason = "no add recurrences in the icmp";
-      return None;
+      return std::nullopt;
     }
   }
 
@@ -848,22 +848,22 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
   const SCEVAddRecExpr *IndVarBase = cast<SCEVAddRecExpr>(LeftSCEV);
   if (IndVarBase->getLoop() != &L) {
     FailureReason = "LHS in cmp is not an AddRec for this loop";
-    return None;
+    return std::nullopt;
   }
   if (!IndVarBase->isAffine()) {
     FailureReason = "LHS in icmp not induction variable";
-    return None;
+    return std::nullopt;
   }
   const SCEV* StepRec = IndVarBase->getStepRecurrence(SE);
   if (!isa<SCEVConstant>(StepRec)) {
     FailureReason = "LHS in icmp not induction variable";
-    return None;
+    return std::nullopt;
   }
   ConstantInt *StepCI = cast<SCEVConstant>(StepRec)->getValue();
 
   if (ICI->isEquality() && !HasNoSignedWrap(IndVarBase)) {
     FailureReason = "LHS in icmp needs nsw for equality predicates";
-    return None;
+    return std::nullopt;
   }
 
   assert(!StepCI->isZero() && "Zero step?");
@@ -926,19 +926,19 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
 
     if (!FoundExpectedPred) {
       FailureReason = "expected icmp slt semantically, found something else";
-      return None;
+      return std::nullopt;
     }
 
     IsSignedPredicate = ICmpInst::isSigned(Pred);
     if (!IsSignedPredicate && !AllowUnsignedLatchCondition) {
       FailureReason = "unsigned latch conditions are explicitly prohibited";
-      return None;
+      return std::nullopt;
     }
 
     if (!isSafeIncreasingBound(IndVarStart, RightSCEV, Step, Pred,
                                LatchBrExitIdx, &L, SE)) {
       FailureReason = "Unsafe loop bounds";
-      return None;
+      return std::nullopt;
     }
     if (LatchBrExitIdx == 0) {
       // We need to increase the right value unless we have already decreased
@@ -989,7 +989,7 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
 
     if (!FoundExpectedPred) {
       FailureReason = "expected icmp sgt semantically, found something else";
-      return None;
+      return std::nullopt;
     }
 
     IsSignedPredicate =
@@ -997,13 +997,13 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE, Loop &L,
 
     if (!IsSignedPredicate && !AllowUnsignedLatchCondition) {
       FailureReason = "unsigned latch conditions are explicitly prohibited";
-      return None;
+      return std::nullopt;
     }
 
     if (!isSafeDecreasingBound(IndVarStart, RightSCEV, Step, Pred,
                                LatchBrExitIdx, &L, SE)) {
       FailureReason = "Unsafe bounds";
-      return None;
+      return std::nullopt;
     }
 
     if (LatchBrExitIdx == 0) {
@@ -1070,9 +1070,9 @@ LoopConstrainer::calculateSubRanges(bool IsSignedPredicate) const {
 
   // We only support wide range checks and narrow latches.
   if (!AllowNarrowLatchCondition && RTy != Ty)
-    return None;
+    return std::nullopt;
   if (RTy->getBitWidth() < Ty->getBitWidth())
-    return None;
+    return std::nullopt;
 
   LoopConstrainer::SubRanges Result;
 
@@ -1592,9 +1592,9 @@ InductiveRangeCheck::computeSafeIterationSpace(
   auto *RCType = dyn_cast<IntegerType>(getBegin()->getType());
   // Do not work with pointer types.
   if (!IVType || !RCType)
-    return None;
+    return std::nullopt;
   if (IVType->getBitWidth() > RCType->getBitWidth())
-    return None;
+    return std::nullopt;
   // IndVar is of the form "A + B * I" (where "I" is the canonical induction
   // variable, that may or may not exist as a real llvm::Value in the loop) and
   // this inductive range check is a range check on the "C + D * I" ("C" is
@@ -1616,19 +1616,19 @@ InductiveRangeCheck::computeSafeIterationSpace(
   // to deal with overflown values.
 
   if (!IndVar->isAffine())
-    return None;
+    return std::nullopt;
 
   const SCEV *A = NoopOrExtend(IndVar->getStart(), RCType, SE, IsLatchSigned);
   const SCEVConstant *B = dyn_cast<SCEVConstant>(
       NoopOrExtend(IndVar->getStepRecurrence(SE), RCType, SE, IsLatchSigned));
   if (!B)
-    return None;
+    return std::nullopt;
   assert(!B->isZero() && "Recurrence with zero step?");
 
   const SCEV *C = getBegin();
   const SCEVConstant *D = dyn_cast<SCEVConstant>(getStep());
   if (D != B)
-    return None;
+    return std::nullopt;
 
   assert(!D->getValue()->isZero() && "Recurrence with zero step?");
   unsigned BitWidth = RCType->getBitWidth();
@@ -1716,7 +1716,7 @@ IntersectSignedRange(ScalarEvolution &SE,
                      const Optional<InductiveRangeCheck::Range> &R1,
                      const InductiveRangeCheck::Range &R2) {
   if (R2.isEmpty(SE, /* IsSigned */ true))
-    return None;
+    return std::nullopt;
   if (!R1)
     return R2;
   auto &R1Value = R1.value();
@@ -1728,7 +1728,7 @@ IntersectSignedRange(ScalarEvolution &SE,
   // TODO: we could widen the smaller range and have this work; but for now we
   // bail out to keep things simple.
   if (R1Value.getType() != R2.getType())
-    return None;
+    return std::nullopt;
 
   const SCEV *NewBegin = SE.getSMaxExpr(R1Value.getBegin(), R2.getBegin());
   const SCEV *NewEnd = SE.getSMinExpr(R1Value.getEnd(), R2.getEnd());
@@ -1736,7 +1736,7 @@ IntersectSignedRange(ScalarEvolution &SE,
   // If the resulting range is empty, just return None.
   auto Ret = InductiveRangeCheck::Range(NewBegin, NewEnd);
   if (Ret.isEmpty(SE, /* IsSigned */ true))
-    return None;
+    return std::nullopt;
   return Ret;
 }
 
@@ -1745,7 +1745,7 @@ IntersectUnsignedRange(ScalarEvolution &SE,
                        const Optional<InductiveRangeCheck::Range> &R1,
                        const InductiveRangeCheck::Range &R2) {
   if (R2.isEmpty(SE, /* IsSigned */ false))
-    return None;
+    return std::nullopt;
   if (!R1)
     return R2;
   auto &R1Value = R1.value();
@@ -1757,7 +1757,7 @@ IntersectUnsignedRange(ScalarEvolution &SE,
   // TODO: we could widen the smaller range and have this work; but for now we
   // bail out to keep things simple.
   if (R1Value.getType() != R2.getType())
-    return None;
+    return std::nullopt;
 
   const SCEV *NewBegin = SE.getUMaxExpr(R1Value.getBegin(), R2.getBegin());
   const SCEV *NewEnd = SE.getUMinExpr(R1Value.getEnd(), R2.getEnd());
@@ -1765,7 +1765,7 @@ IntersectUnsignedRange(ScalarEvolution &SE,
   // If the resulting range is empty, just return None.
   auto Ret = InductiveRangeCheck::Range(NewBegin, NewEnd);
   if (Ret.isEmpty(SE, /* IsSigned */ false))
-    return None;
+    return std::nullopt;
   return Ret;
 }
 

llvm/lib/Transforms/Scalar/LoopFuse.cpp

@@ -645,7 +645,7 @@ private:
   void collectFusionCandidates(const LoopVector &LV) {
     for (Loop *L : LV) {
       TTI::PeelingPreferences PP =
-          gatherPeelingPreferences(L, SE, TTI, None, None);
+          gatherPeelingPreferences(L, SE, TTI, std::nullopt, std::nullopt);
       FusionCandidate CurrCand(L, DT, &PDT, ORE, PP);
       if (!CurrCand.isEligibleForFusion(SE))
         continue;
@@ -708,14 +708,14 @@ private:
     if (isa<SCEVCouldNotCompute>(TripCount0)) {
       UncomputableTripCount++;
       LLVM_DEBUG(dbgs() << "Trip count of first loop could not be computed!");
-      return {false, None};
+      return {false, std::nullopt};
     }
 
     const SCEV *TripCount1 = SE.getBackedgeTakenCount(FC1.L);
     if (isa<SCEVCouldNotCompute>(TripCount1)) {
       UncomputableTripCount++;
       LLVM_DEBUG(dbgs() << "Trip count of second loop could not be computed!");
-      return {false, None};
+      return {false, std::nullopt};
     }
 
     LLVM_DEBUG(dbgs() << "\tTrip counts: " << *TripCount0 << " & "
@@ -740,7 +740,7 @@ private:
       LLVM_DEBUG(dbgs() << "Loop(s) do not have a single exit point or do not "
                            "have a constant number of iterations. Peeling "
                            "is not benefical\n");
-      return {false, None};
+      return {false, std::nullopt};
     }
 
     Optional<unsigned> Difference;

llvm/lib/Transforms/Scalar/LoopPredication.cpp

@@ -392,10 +392,10 @@ LoopPredication::parseLoopICmp(ICmpInst *ICI) {
 
   const SCEV *LHSS = SE->getSCEV(LHS);
   if (isa<SCEVCouldNotCompute>(LHSS))
-    return None;
+    return std::nullopt;
   const SCEV *RHSS = SE->getSCEV(RHS);
   if (isa<SCEVCouldNotCompute>(RHSS))
-    return None;
+    return std::nullopt;
 
   // Canonicalize RHS to be loop invariant bound, LHS - a loop computable IV
   if (SE->isLoopInvariant(LHSS, L)) {
@@ -406,7 +406,7 @@ LoopPredication::parseLoopICmp(ICmpInst *ICI) {
 
   const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(LHSS);
   if (!AR || AR->getLoop() != L)
-    return None;
+    return std::nullopt;
 
   return LoopICmp(Pred, AR, RHSS);
 }
@@ -494,9 +494,9 @@ static std::optional<LoopICmp> generateLoopLatchCheck(const DataLayout &DL,
   // For now, bail out if latch type is narrower than range type.
   if (DL.getTypeSizeInBits(LatchType).getFixedSize() <
       DL.getTypeSizeInBits(RangeCheckType).getFixedSize())
-    return None;
+    return std::nullopt;
   if (!isSafeToTruncateWideIVType(DL, SE, LatchCheck, RangeCheckType))
-    return None;
+    return std::nullopt;
   // We can now safely identify the truncated version of the IV and limit for
   // RangeCheckType.
   LoopICmp NewLatchCheck;
@@ -504,7 +504,7 @@ static std::optional<LoopICmp> generateLoopLatchCheck(const DataLayout &DL,
   NewLatchCheck.IV = dyn_cast<SCEVAddRecExpr>(
       SE.getTruncateExpr(LatchCheck.IV, RangeCheckType));
   if (!NewLatchCheck.IV)
-    return None;
+    return std::nullopt;
   NewLatchCheck.Limit = SE.getTruncateExpr(LatchCheck.Limit, RangeCheckType);
   LLVM_DEBUG(dbgs() << "IV of type: " << *LatchType
                     << "can be represented as range check type:"
@@ -598,12 +598,12 @@ Optional<Value *> LoopPredication::widenICmpRangeCheckIncrementingLoop(
       !isLoopInvariantValue(LatchStart) ||
       !isLoopInvariantValue(LatchLimit)) {
     LLVM_DEBUG(dbgs() << "Can't expand limit check!\n");
-    return None;
+    return std::nullopt;
   }
   if (!Expander.isSafeToExpandAt(LatchStart, Guard) ||
       !Expander.isSafeToExpandAt(LatchLimit, Guard)) {
     LLVM_DEBUG(dbgs() << "Can't expand limit check!\n");
-    return None;
+    return std::nullopt;
   }
 
   // guardLimit - guardStart + latchStart - 1
@@ -641,12 +641,12 @@ Optional<Value *> LoopPredication::widenICmpRangeCheckDecrementingLoop(
       !isLoopInvariantValue(LatchStart) ||
       !isLoopInvariantValue(LatchLimit)) {
     LLVM_DEBUG(dbgs() << "Can't expand limit check!\n");
-    return None;
+    return std::nullopt;
   }
   if (!Expander.isSafeToExpandAt(LatchStart, Guard) ||
       !Expander.isSafeToExpandAt(LatchLimit, Guard)) {
     LLVM_DEBUG(dbgs() << "Can't expand limit check!\n");
-    return None;
+    return std::nullopt;
   }
   // The decrement of the latch check IV should be the same as the
   // rangeCheckIV.
@@ -655,7 +655,7 @@ Optional<Value *> LoopPredication::widenICmpRangeCheckDecrementingLoop(
     LLVM_DEBUG(dbgs() << "Not the same. PostDecLatchCheckIV: "
                       << *PostDecLatchCheckIV
                       << "  and RangeCheckIV: " << *RangeCheck.IV << "\n");
-    return None;
+    return std::nullopt;
   }
 
   // Generate the widened condition for CountDownLoop:
@@ -701,26 +701,26 @@ Optional<Value *> LoopPredication::widenICmpRangeCheck(ICmpInst *ICI,
   auto RangeCheck = parseLoopICmp(ICI);
   if (!RangeCheck) {
     LLVM_DEBUG(dbgs() << "Failed to parse the loop latch condition!\n");
-    return None;
+    return std::nullopt;
   }
   LLVM_DEBUG(dbgs() << "Guard check:\n");
   LLVM_DEBUG(RangeCheck->dump());
   if (RangeCheck->Pred != ICmpInst::ICMP_ULT) {
     LLVM_DEBUG(dbgs() << "Unsupported range check predicate("
                       << RangeCheck->Pred << ")!\n");
-    return None;
+    return std::nullopt;
   }
   auto *RangeCheckIV = RangeCheck->IV;
   if (!RangeCheckIV->isAffine()) {
     LLVM_DEBUG(dbgs() << "Range check IV is not affine!\n");
-    return None;
+    return std::nullopt;
   }
   auto *Step = RangeCheckIV->getStepRecurrence(*SE);
   // We cannot just compare with latch IV step because the latch and range IVs
   // may have different types.
   if (!isSupportedStep(Step)) {
     LLVM_DEBUG(dbgs() << "Range check and latch have IVs different steps!\n");
-    return None;
+    return std::nullopt;
   }
   auto *Ty = RangeCheckIV->getType();
   auto CurrLatchCheckOpt = generateLoopLatchCheck(*DL, *SE, LatchCheck, Ty);
@@ -728,7 +728,7 @@ Optional<Value *> LoopPredication::widenICmpRangeCheck(ICmpInst *ICI,
     LLVM_DEBUG(dbgs() << "Failed to generate a loop latch check "
                          "corresponding to range type: "
                       << *Ty << "\n");
-    return None;
+    return std::nullopt;
   }
 
   LoopICmp CurrLatchCheck = *CurrLatchCheckOpt;
@@ -739,7 +739,7 @@ Optional<Value *> LoopPredication::widenICmpRangeCheck(ICmpInst *ICI,
          "Range and latch steps should be of same type!");
   if (Step != CurrLatchCheck.IV->getStepRecurrence(*SE)) {
     LLVM_DEBUG(dbgs() << "Range and latch have different step values!\n");
-    return None;
+    return std::nullopt;
   }
 
   if (Step->isOne())
@@ -879,13 +879,13 @@ Optional<LoopICmp> LoopPredication::parseLoopLatchICmp() {
   BasicBlock *LoopLatch = L->getLoopLatch();
   if (!LoopLatch) {
     LLVM_DEBUG(dbgs() << "The loop doesn't have a single latch!\n");
-    return None;
+    return std::nullopt;
   }
 
   auto *BI = dyn_cast<BranchInst>(LoopLatch->getTerminator());
   if (!BI || !BI->isConditional()) {
     LLVM_DEBUG(dbgs() << "Failed to match the latch terminator!\n");
-    return None;
+    return std::nullopt;
   }
   BasicBlock *TrueDest = BI->getSuccessor(0);
   assert(
@@ -895,12 +895,12 @@ Optional<LoopICmp> LoopPredication::parseLoopLatchICmp() {
   auto *ICI = dyn_cast<ICmpInst>(BI->getCondition());
   if (!ICI) {
     LLVM_DEBUG(dbgs() << "Failed to match the latch condition!\n");
-    return None;
+    return std::nullopt;
   }
   auto Result = parseLoopICmp(ICI);
   if (!Result) {
     LLVM_DEBUG(dbgs() << "Failed to parse the loop latch condition!\n");
-    return None;
+    return std::nullopt;
   }
 
   if (TrueDest != L->getHeader())
@@ -910,13 +910,13 @@ Optional<LoopICmp> LoopPredication::parseLoopLatchICmp() {
   // recurrence.
   if (!Result->IV->isAffine()) {
     LLVM_DEBUG(dbgs() << "The induction variable is not affine!\n");
-    return None;
+    return std::nullopt;
   }
 
   auto *Step = Result->IV->getStepRecurrence(*SE);
   if (!isSupportedStep(Step)) {
     LLVM_DEBUG(dbgs() << "Unsupported loop stride(" << *Step << ")!\n");
-    return None;
+    return std::nullopt;
   }
 
   auto IsUnsupportedPredicate = [](const SCEV *Step, ICmpInst::Predicate Pred) {
@@ -934,7 +934,7 @@ Optional<LoopICmp> LoopPredication::parseLoopLatchICmp() {
   if (IsUnsupportedPredicate(Step, Result->Pred)) {
     LLVM_DEBUG(dbgs() << "Unsupported loop latch predicate(" << Result->Pred
                       << ")!\n");
-    return None;
+    return std::nullopt;
   }
 
   return Result;

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -6620,17 +6620,17 @@ canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
                       const LoopInfo &LI) {
   if (!L->isInnermost()) {
     LLVM_DEBUG(dbgs() << "Cannot fold on non-innermost loop\n");
-    return None;
+    return std::nullopt;
   }
   // Only inspect on simple loop structure
   if (!L->isLoopSimplifyForm()) {
     LLVM_DEBUG(dbgs() << "Cannot fold on non-simple loop\n");
-    return None;
+    return std::nullopt;
   }
 
   if (!SE.hasLoopInvariantBackedgeTakenCount(L)) {
     LLVM_DEBUG(dbgs() << "Cannot fold on backedge that is loop variant\n");
-    return None;
+    return std::nullopt;
   }
 
   BasicBlock *LoopPreheader = L->getLoopPreheader();
@@ -6640,18 +6640,18 @@ canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
   // Terminating condition is foldable when it is an eq/ne icmp
   BranchInst *BI = cast<BranchInst>(LoopLatch->getTerminator());
   if (BI->isUnconditional())
-    return None;
+    return std::nullopt;
   Value *TermCond = BI->getCondition();
   if (!isa<ICmpInst>(TermCond) || !cast<ICmpInst>(TermCond)->isEquality()) {
     LLVM_DEBUG(dbgs() << "Cannot fold on branching condition that is not an "
                          "ICmpInst::eq / ICmpInst::ne\n");
-    return None;
+    return std::nullopt;
   }
   if (!TermCond->hasOneUse()) {
     LLVM_DEBUG(
         dbgs()
         << "Cannot replace terminating condition with more than one use\n");
-    return None;
+    return std::nullopt;
   }
 
   // For `IsToFold`, a primary IV can be replaced by other affine AddRec when it
@@ -6769,7 +6769,7 @@ canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
              << "  ToHelpFold: " << *ToHelpFold << "\n");
 
   if (!ToFold || !ToHelpFold)
-    return None;
+    return std::nullopt;
   return {{ToFold, {ToHelpFold, TermValueS}}};
 }
 

llvm/lib/Transforms/Scalar/LoopUnrollAndJamPass.cpp

@@ -284,11 +284,11 @@ tryToUnrollAndJamLoop(Loop *L, DominatorTree &DT, LoopInfo *LI,
                       ScalarEvolution &SE, const TargetTransformInfo &TTI,
                       AssumptionCache &AC, DependenceInfo &DI,
                       OptimizationRemarkEmitter &ORE, int OptLevel) {
-  TargetTransformInfo::UnrollingPreferences UP =
+  TargetTransformInfo::UnrollingPreferences UP = gatherUnrollingPreferences(
-      gatherUnrollingPreferences(L, SE, TTI, nullptr, nullptr, ORE, OptLevel,
+      L, SE, TTI, nullptr, nullptr, ORE, OptLevel, std::nullopt, std::nullopt,
-                                 None, None, None, None, None, None);
+      std::nullopt, std::nullopt, std::nullopt, std::nullopt);
   TargetTransformInfo::PeelingPreferences PP =
-      gatherPeelingPreferences(L, SE, TTI, None, None);
+      gatherPeelingPreferences(L, SE, TTI, std::nullopt, std::nullopt);
 
   TransformationMode EnableMode = hasUnrollAndJamTransformation(L);
   if (EnableMode & TM_Disable)

llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp

@@ -359,11 +359,11 @@ static Optional<EstimatedUnrollCost> analyzeLoopUnrollCost(
   // Only analyze inner loops. We can't properly estimate cost of nested loops
   // and we won't visit inner loops again anyway.
   if (!L->isInnermost())
-    return None;
+    return std::nullopt;
 
   // Don't simulate loops with a big or unknown tripcount
   if (!TripCount || TripCount > MaxIterationsCountToAnalyze)
-    return None;
+    return std::nullopt;
 
   SmallSetVector<BasicBlock *, 16> BBWorklist;
   SmallSetVector<std::pair<BasicBlock *, BasicBlock *>, 4> ExitWorklist;
@@ -559,7 +559,7 @@ static Optional<EstimatedUnrollCost> analyzeLoopUnrollCost(
           const Function *Callee = CI->getCalledFunction();
           if (!Callee || TTI.isLoweredToCall(Callee)) {
             LLVM_DEBUG(dbgs() << "Can't analyze cost of loop with call\n");
-            return None;
+            return std::nullopt;
           }
         }
 
@@ -574,7 +574,7 @@ static Optional<EstimatedUnrollCost> analyzeLoopUnrollCost(
                             << "  UnrolledCost: " << UnrolledCost
                             << ", MaxUnrolledLoopSize: " << MaxUnrolledLoopSize
                             << "\n");
-          return None;
+          return std::nullopt;
         }
       }
 
@@ -632,7 +632,7 @@ static Optional<EstimatedUnrollCost> analyzeLoopUnrollCost(
     if (UnrolledCost == RolledDynamicCost) {
       LLVM_DEBUG(dbgs() << "  No opportunities found.. exiting.\n"
                         << "  UnrolledCost: " << UnrolledCost << "\n");
-      return None;
+      return std::nullopt;
     }
   }
 
@@ -798,7 +798,7 @@ shouldPragmaUnroll(Loop *L, const PragmaInfo &PInfo,
     return TripCount;
 
   // if didn't return until here, should continue to other priorties
-  return None;
+  return std::nullopt;
 }
 
 static std::optional<unsigned> shouldFullUnroll(
@@ -809,7 +809,7 @@ static std::optional<unsigned> shouldFullUnroll(
   assert(FullUnrollTripCount && "should be non-zero!");
 
   if (FullUnrollTripCount > UP.FullUnrollMaxCount)
-    return None;
+    return std::nullopt;
 
   // When computing the unrolled size, note that BEInsns are not replicated
   // like the rest of the loop body.
@@ -828,7 +828,7 @@ static std::optional<unsigned> shouldFullUnroll(
     if (Cost->UnrolledCost < UP.Threshold * Boost / 100)
       return FullUnrollTripCount;
   }
-  return None;
+  return std::nullopt;
 }
 
 static std::optional<unsigned>
@@ -837,7 +837,7 @@ shouldPartialUnroll(const unsigned LoopSize, const unsigned TripCount,
                     const TargetTransformInfo::UnrollingPreferences &UP) {
 
   if (!TripCount)
-    return None;
+    return std::nullopt;
 
   if (!UP.Partial) {
     LLVM_DEBUG(dbgs() << "  will not try to unroll partially because "
@@ -1378,13 +1378,15 @@ public:
   Optional<unsigned> ProvidedFullUnrollMaxCount;
 
   LoopUnroll(int OptLevel = 2, bool OnlyWhenForced = false,
-             bool ForgetAllSCEV = false, Optional<unsigned> Threshold = None,
+             bool ForgetAllSCEV = false,
-             Optional<unsigned> Count = None,
+             Optional<unsigned> Threshold = std::nullopt,
-             Optional<bool> AllowPartial = None, Optional<bool> Runtime = None,
+             Optional<unsigned> Count = std::nullopt,
-             Optional<bool> UpperBound = None,
+             Optional<bool> AllowPartial = std::nullopt,
-             Optional<bool> AllowPeeling = None,
+             Optional<bool> Runtime = std::nullopt,
-             Optional<bool> AllowProfileBasedPeeling = None,
+             Optional<bool> UpperBound = std::nullopt,
-             Optional<unsigned> ProvidedFullUnrollMaxCount = None)
+             Optional<bool> AllowPeeling = std::nullopt,
+             Optional<bool> AllowProfileBasedPeeling = std::nullopt,
+             Optional<unsigned> ProvidedFullUnrollMaxCount = std::nullopt)
       : LoopPass(ID), OptLevel(OptLevel), OnlyWhenForced(OnlyWhenForced),
         ForgetAllSCEV(ForgetAllSCEV), ProvidedCount(std::move(Count)),
         ProvidedThreshold(Threshold), ProvidedAllowPartial(AllowPartial),
@@ -1456,12 +1458,12 @@ Pass *llvm::createLoopUnrollPass(int OptLevel, bool OnlyWhenForced,
   // callers.
   return new LoopUnroll(
       OptLevel, OnlyWhenForced, ForgetAllSCEV,
-      Threshold == -1 ? None : Optional<unsigned>(Threshold),
+      Threshold == -1 ? std::nullopt : Optional<unsigned>(Threshold),
-      Count == -1 ? None : Optional<unsigned>(Count),
+      Count == -1 ? std::nullopt : Optional<unsigned>(Count),
-      AllowPartial == -1 ? None : Optional<bool>(AllowPartial),
+      AllowPartial == -1 ? std::nullopt : Optional<bool>(AllowPartial),
-      Runtime == -1 ? None : Optional<bool>(Runtime),
+      Runtime == -1 ? std::nullopt : Optional<bool>(Runtime),
-      UpperBound == -1 ? None : Optional<bool>(UpperBound),
+      UpperBound == -1 ? std::nullopt : Optional<bool>(UpperBound),
-      AllowPeeling == -1 ? None : Optional<bool>(AllowPeeling));
+      AllowPeeling == -1 ? std::nullopt : Optional<bool>(AllowPeeling));
 }
 
 Pass *llvm::createSimpleLoopUnrollPass(int OptLevel, bool OnlyWhenForced,
@@ -1489,16 +1491,17 @@ PreservedAnalyses LoopFullUnrollPass::run(Loop &L, LoopAnalysisManager &AM,
 
   std::string LoopName = std::string(L.getName());
 
-  bool Changed = tryToUnrollLoop(&L, AR.DT, &AR.LI, AR.SE, AR.TTI, AR.AC, ORE,
+  bool Changed =
-                                 /*BFI*/ nullptr, /*PSI*/ nullptr,
+      tryToUnrollLoop(&L, AR.DT, &AR.LI, AR.SE, AR.TTI, AR.AC, ORE,
-                                 /*PreserveLCSSA*/ true, OptLevel,
+                      /*BFI*/ nullptr, /*PSI*/ nullptr,
-                                 OnlyWhenForced, ForgetSCEV, /*Count*/ None,
+                      /*PreserveLCSSA*/ true, OptLevel, OnlyWhenForced,
-                                 /*Threshold*/ None, /*AllowPartial*/ false,
+                      ForgetSCEV, /*Count*/ std::nullopt,
-                                 /*Runtime*/ false, /*UpperBound*/ false,
+                      /*Threshold*/ std::nullopt, /*AllowPartial*/ false,
-                                 /*AllowPeeling*/ true,
+                      /*Runtime*/ false, /*UpperBound*/ false,
-                                 /*AllowProfileBasedPeeling*/ false,
+                      /*AllowPeeling*/ true,
-                                 /*FullUnrollMaxCount*/ None) !=
+                      /*AllowProfileBasedPeeling*/ false,
-                 LoopUnrollResult::Unmodified;
+                      /*FullUnrollMaxCount*/ std::nullopt) !=
+      LoopUnrollResult::Unmodified;
   if (!Changed)
     return PreservedAnalyses::all();
 
@@ -1618,9 +1621,9 @@ PreservedAnalyses LoopUnrollPass::run(Function &F,
     LoopUnrollResult Result = tryToUnrollLoop(
         &L, DT, &LI, SE, TTI, AC, ORE, BFI, PSI,
         /*PreserveLCSSA*/ true, UnrollOpts.OptLevel, UnrollOpts.OnlyWhenForced,
-        UnrollOpts.ForgetSCEV, /*Count*/ None,
+        UnrollOpts.ForgetSCEV, /*Count*/ std::nullopt,
-        /*Threshold*/ None, UnrollOpts.AllowPartial, UnrollOpts.AllowRuntime,
+        /*Threshold*/ std::nullopt, UnrollOpts.AllowPartial,
-        UnrollOpts.AllowUpperBound, LocalAllowPeeling,
+        UnrollOpts.AllowRuntime, UnrollOpts.AllowUpperBound, LocalAllowPeeling,
         UnrollOpts.AllowProfileBasedPeeling, UnrollOpts.FullUnrollMaxCount);
     Changed |= Result != LoopUnrollResult::Unmodified;
 
@@ -1646,18 +1649,18 @@ void LoopUnrollPass::printPipeline(
   static_cast<PassInfoMixin<LoopUnrollPass> *>(this)->printPipeline(
       OS, MapClassName2PassName);
   OS << "<";
-  if (UnrollOpts.AllowPartial != None)
+  if (UnrollOpts.AllowPartial != std::nullopt)
     OS << (UnrollOpts.AllowPartial.value() ? "" : "no-") << "partial;";
-  if (UnrollOpts.AllowPeeling != None)
+  if (UnrollOpts.AllowPeeling != std::nullopt)
     OS << (UnrollOpts.AllowPeeling.value() ? "" : "no-") << "peeling;";
-  if (UnrollOpts.AllowRuntime != None)
+  if (UnrollOpts.AllowRuntime != std::nullopt)
     OS << (UnrollOpts.AllowRuntime.value() ? "" : "no-") << "runtime;";
-  if (UnrollOpts.AllowUpperBound != None)
+  if (UnrollOpts.AllowUpperBound != std::nullopt)
     OS << (UnrollOpts.AllowUpperBound.value() ? "" : "no-") << "upperbound;";
-  if (UnrollOpts.AllowProfileBasedPeeling != None)
+  if (UnrollOpts.AllowProfileBasedPeeling != std::nullopt)
     OS << (UnrollOpts.AllowProfileBasedPeeling.value() ? "" : "no-")
        << "profile-peeling;";
-  if (UnrollOpts.FullUnrollMaxCount != None)
+  if (UnrollOpts.FullUnrollMaxCount != std::nullopt)
     OS << "full-unroll-max=" << UnrollOpts.FullUnrollMaxCount << ";";
   OS << "O" << UnrollOpts.OptLevel;
   OS << ">";

llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp

@@ -590,7 +590,7 @@ bool MemCpyOptPass::moveUp(StoreInst *SI, Instruction *P, const LoadInst *LI) {
     if (!isGuaranteedToTransferExecutionToSuccessor(C))
       return false;
 
-    bool MayAlias = isModOrRefSet(AA->getModRefInfo(C, None));
+    bool MayAlias = isModOrRefSet(AA->getModRefInfo(C, std::nullopt));
 
     bool NeedLift = false;
     if (Args.erase(C))

llvm/lib/Transforms/Scalar/MergeICmps.cpp

@@ -310,19 +310,19 @@ Optional<BCECmp> visitICmp(const ICmpInst *const CmpI,
   // other comparisons as we would create an orphan use of the value.
   if (!CmpI->hasOneUse()) {
     LLVM_DEBUG(dbgs() << "cmp has several uses\n");
-    return None;
+    return std::nullopt;
   }
   if (CmpI->getPredicate() != ExpectedPredicate)
-    return None;
+    return std::nullopt;
   LLVM_DEBUG(dbgs() << "cmp "
                     << (ExpectedPredicate == ICmpInst::ICMP_EQ ? "eq" : "ne")
                     << "\n");
   auto Lhs = visitICmpLoadOperand(CmpI->getOperand(0), BaseId);
   if (!Lhs.BaseId)
-    return None;
+    return std::nullopt;
   auto Rhs = visitICmpLoadOperand(CmpI->getOperand(1), BaseId);
   if (!Rhs.BaseId)
-    return None;
+    return std::nullopt;
   const auto &DL = CmpI->getModule()->getDataLayout();
   return BCECmp(std::move(Lhs), std::move(Rhs),
                 DL.getTypeSizeInBits(CmpI->getOperand(0)->getType()), CmpI);
@@ -333,9 +333,11 @@ Optional<BCECmp> visitICmp(const ICmpInst *const CmpI,
 Optional<BCECmpBlock> visitCmpBlock(Value *const Val, BasicBlock *const Block,
                                     const BasicBlock *const PhiBlock,
                                     BaseIdentifier &BaseId) {
-  if (Block->empty()) return None;
+  if (Block->empty())
+    return std::nullopt;
   auto *const BranchI = dyn_cast<BranchInst>(Block->getTerminator());
-  if (!BranchI) return None;
+  if (!BranchI)
+    return std::nullopt;
   LLVM_DEBUG(dbgs() << "branch\n");
   Value *Cond;
   ICmpInst::Predicate ExpectedPredicate;
@@ -351,7 +353,8 @@ Optional<BCECmpBlock> visitCmpBlock(Value *const Val, BasicBlock *const Block,
     // chained).
     const auto *const Const = cast<ConstantInt>(Val);
     LLVM_DEBUG(dbgs() << "const\n");
-    if (!Const->isZero()) return None;
+    if (!Const->isZero())
+      return std::nullopt;
     LLVM_DEBUG(dbgs() << "false\n");
     assert(BranchI->getNumSuccessors() == 2 && "expecting a cond branch");
     BasicBlock *const FalseBlock = BranchI->getSuccessor(1);
@@ -361,12 +364,13 @@ Optional<BCECmpBlock> visitCmpBlock(Value *const Val, BasicBlock *const Block,
   }
 
   auto *CmpI = dyn_cast<ICmpInst>(Cond);
-  if (!CmpI) return None;
+  if (!CmpI)
+    return std::nullopt;
   LLVM_DEBUG(dbgs() << "icmp\n");
 
   Optional<BCECmp> Result = visitICmp(CmpI, ExpectedPredicate, BaseId);
   if (!Result)
-    return None;
+    return std::nullopt;
 
   BCECmpBlock::InstructionSet BlockInsts(
       {Result->Lhs.LoadI, Result->Rhs.LoadI, Result->CmpI, BranchI});

llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp

@@ -301,7 +301,7 @@ static ArrayRef<Use> GetDeoptBundleOperands(const CallBase *Call) {
   if (!DeoptBundle) {
     assert(AllowStatepointWithNoDeoptInfo &&
            "Found non-leaf call without deopt info!");
-    return None;
+    return std::nullopt;
   }
 
   return DeoptBundle->Inputs;

llvm/lib/Transforms/Scalar/Scalarizer.cpp

@@ -489,11 +489,11 @@ ScalarizerVisitor::getVectorLayout(Type *Ty, Align Alignment,
   // Make sure we're dealing with a vector.
   Layout.VecTy = dyn_cast<VectorType>(Ty);
   if (!Layout.VecTy)
-    return None;
+    return std::nullopt;
   // Check that we're dealing with full-byte elements.
   Layout.ElemTy = Layout.VecTy->getElementType();
   if (!DL.typeSizeEqualsStoreSize(Layout.ElemTy))
-    return None;
+    return std::nullopt;
   Layout.VecAlign = Alignment;
   Layout.ElemSize = DL.getTypeStoreSize(Layout.ElemTy);
   return Layout;

llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp

@@ -124,8 +124,8 @@ struct NonTrivialUnswitchCandidate {
   TinyPtrVector<Value *> Invariants;
   Optional<InstructionCost> Cost;
   NonTrivialUnswitchCandidate(Instruction *TI, ArrayRef<Value *> Invariants,
-                              Optional<InstructionCost> Cost = None)
+                              Optional<InstructionCost> Cost = std::nullopt)
-      : TI(TI), Invariants(Invariants), Cost(Cost) {};
+      : TI(TI), Invariants(Invariants), Cost(Cost){};
 };
 } // end anonymous namespace.
 

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

@@ -427,7 +427,7 @@ static bool removeRedundantDbgInstrsUsingForwardScan(BasicBlock *BB) {
       VariableMap;
   for (auto &I : *BB) {
     if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(&I)) {
-      DebugVariable Key(DVI->getVariable(), None,
+      DebugVariable Key(DVI->getVariable(), std::nullopt,
                         DVI->getDebugLoc()->getInlinedAt());
       auto VMI = VariableMap.find(Key);
       auto *DAI = dyn_cast<DbgAssignIntrinsic>(DVI);
@@ -488,7 +488,7 @@ static bool remomveUndefDbgAssignsFromEntryBlock(BasicBlock *BB) {
   DenseSet<DebugVariable> SeenDefForAggregate;
   // Returns the DebugVariable for DVI with no fragment info.
   auto GetAggregateVariable = [](DbgValueInst *DVI) {
-    return DebugVariable(DVI->getVariable(), None,
+    return DebugVariable(DVI->getVariable(), std::nullopt,
                          DVI->getDebugLoc()->getInlinedAt());
   };
 

llvm/lib/Transforms/Utils/BypassSlowDivision.cpp

@@ -357,12 +357,12 @@ Optional<QuotRemPair> FastDivInsertionTask::insertFastDivAndRem() {
   VisitedSetTy SetL;
   ValueRange DividendRange = getValueRange(Dividend, SetL);
   if (DividendRange == VALRNG_LIKELY_LONG)
-    return None;
+    return std::nullopt;
 
   VisitedSetTy SetR;
   ValueRange DivisorRange = getValueRange(Divisor, SetR);
   if (DivisorRange == VALRNG_LIKELY_LONG)
-    return None;
+    return std::nullopt;
 
   bool DividendShort = (DividendRange == VALRNG_KNOWN_SHORT);
   bool DivisorShort = (DivisorRange == VALRNG_KNOWN_SHORT);
@@ -387,7 +387,7 @@ Optional<QuotRemPair> FastDivInsertionTask::insertFastDivAndRem() {
     // If the divisor is not a constant, DAGCombiner will convert it to a
     // multiplication by a magic constant.  It isn't clear if it is worth
     // introducing control flow to get a narrower multiply.
-    return None;
+    return std::nullopt;
   }
 
   // After Constant Hoisting pass, long constants may be represented as
@@ -397,7 +397,7 @@ Optional<QuotRemPair> FastDivInsertionTask::insertFastDivAndRem() {
   if (auto *BCI = dyn_cast<BitCastInst>(Divisor))
     if (BCI->getParent() == SlowDivOrRem->getParent() &&
         isa<ConstantInt>(BCI->getOperand(0)))
-      return None;
+      return std::nullopt;
 
   IRBuilder<> Builder(MainBB, MainBB->end());
   Builder.SetCurrentDebugLocation(SlowDivOrRem->getDebugLoc());

llvm/lib/Transforms/Utils/CodeExtractor.cpp

@@ -1539,7 +1539,8 @@ static void fixupDebugInfoPostExtraction(Function &OldFunc, Function &NewFunc,
   assert(OldSP->getUnit() && "Missing compile unit for subprogram");
   DIBuilder DIB(*OldFunc.getParent(), /*AllowUnresolved=*/false,
                 OldSP->getUnit());
-  auto SPType = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
+  auto SPType =
+      DIB.createSubroutineType(DIB.getOrCreateTypeArray(std::nullopt));
   DISubprogram::DISPFlags SPFlags = DISubprogram::SPFlagDefinition |
                                     DISubprogram::SPFlagOptimized |
                                     DISubprogram::SPFlagLocalToUnit;

llvm/lib/Transforms/Utils/CodeMoverUtils.cpp

@@ -129,7 +129,7 @@ const Optional<ControlConditions> ControlConditions::collectControlConditions(
     // Limitation: can only handle branch instruction currently.
     const BranchInst *BI = dyn_cast<BranchInst>(IDom->getTerminator());
     if (!BI)
-      return None;
+      return std::nullopt;
 
     bool Inserted = false;
     if (PDT.dominates(CurBlock, IDom)) {
@@ -149,13 +149,13 @@ const Optional<ControlConditions> ControlConditions::collectControlConditions(
       Inserted = Conditions.addControlCondition(
           ControlCondition(BI->getCondition(), false));
     } else
-      return None;
+      return std::nullopt;
 
     if (Inserted)
       ++NumConditions;
 
     if (MaxLookup != 0 && NumConditions > MaxLookup)
-      return None;
+      return std::nullopt;
 
     CurBlock = IDom;
   } while (CurBlock != &Dominator);
@@ -252,13 +252,13 @@ bool llvm::isControlFlowEquivalent(const BasicBlock &BB0, const BasicBlock &BB1,
   const Optional<ControlConditions> BB0Conditions =
       ControlConditions::collectControlConditions(BB0, *CommonDominator, DT,
                                                   PDT);
-  if (BB0Conditions == None)
+  if (BB0Conditions == std::nullopt)
     return false;
 
   const Optional<ControlConditions> BB1Conditions =
       ControlConditions::collectControlConditions(BB1, *CommonDominator, DT,
                                                   PDT);
-  if (BB1Conditions == None)
+  if (BB1Conditions == std::nullopt)
     return false;
 
   return BB0Conditions->isEquivalent(*BB1Conditions);

llvm/lib/Transforms/Utils/Debugify.cpp

@@ -114,7 +114,8 @@ bool llvm::applyDebugifyMetadata(
       continue;
 
     bool InsertedDbgVal = false;
-    auto SPType = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
+    auto SPType =
+        DIB.createSubroutineType(DIB.getOrCreateTypeArray(std::nullopt));
     DISubprogram::DISPFlags SPFlags =
         DISubprogram::SPFlagDefinition | DISubprogram::SPFlagOptimized;
     if (F.hasPrivateLinkage() || F.hasInternalLinkage())

llvm/lib/Transforms/Utils/InlineFunction.cpp

@@ -1083,7 +1083,7 @@ void ScopedAliasMetadataDeepCloner::clone() {
 
   SmallVector<TempMDTuple, 16> DummyNodes;
   for (const MDNode *I : MD) {
-    DummyNodes.push_back(MDTuple::getTemporary(I->getContext(), None));
+    DummyNodes.push_back(MDTuple::getTemporary(I->getContext(), std::nullopt));
     MDMap[I].reset(DummyNodes.back().get());
   }
 
@@ -1896,7 +1896,8 @@ static void updateCallProfile(Function *Callee, const ValueToValueMapTy &VMap,
                               BlockFrequencyInfo *CallerBFI) {
   if (CalleeEntryCount.isSynthetic() || CalleeEntryCount.getCount() < 1)
     return;
-  auto CallSiteCount = PSI ? PSI->getProfileCount(TheCall, CallerBFI) : None;
+  auto CallSiteCount =
+      PSI ? PSI->getProfileCount(TheCall, CallerBFI) : std::nullopt;
   int64_t CallCount =
       std::min(CallSiteCount.value_or(0), CalleeEntryCount.getCount());
   updateProfileCallee(Callee, -CallCount, &VMap);

llvm/lib/Transforms/Utils/Local.cpp

@@ -2174,7 +2174,7 @@ bool llvm::replaceAllDbgUsesWith(Instruction &From, Value &To,
       // Without knowing signedness, sign/zero extension isn't possible.
       auto Signedness = Var->getSignedness();
       if (!Signedness)
-        return None;
+        return std::nullopt;
 
       bool Signed = *Signedness == DIBasicType::Signedness::Signed;
       return DIExpression::appendExt(DII.getExpression(), ToBits, FromBits,
@@ -2912,7 +2912,7 @@ void llvm::copyRangeMetadata(const DataLayout &DL, const LoadInst &OldLI,
 
   unsigned BitWidth = DL.getPointerTypeSizeInBits(NewTy);
   if (!getConstantRangeFromMetadata(*N).contains(APInt(BitWidth, 0))) {
-    MDNode *NN = MDNode::get(OldLI.getContext(), None);
+    MDNode *NN = MDNode::get(OldLI.getContext(), std::nullopt);
     NewLI.setMetadata(LLVMContext::MD_nonnull, NN);
   }
 }
@@ -3021,7 +3021,7 @@ collectBitParts(Value *V, bool MatchBSwaps, bool MatchBitReversals,
   if (I != BPS.end())
     return I->second;
 
-  auto &Result = BPS[V] = None;
+  auto &Result = BPS[V] = std::nullopt;
   auto BitWidth = V->getType()->getScalarSizeInBits();
 
   // Can't do integer/elements > 128 bits.
@@ -3057,7 +3057,7 @@ collectBitParts(Value *V, bool MatchBSwaps, bool MatchBitReversals,
         if (A->Provenance[BitIdx] != BitPart::Unset &&
             B->Provenance[BitIdx] != BitPart::Unset &&
             A->Provenance[BitIdx] != B->Provenance[BitIdx])
-          return Result = None;
+          return Result = std::nullopt;
 
         if (A->Provenance[BitIdx] == BitPart::Unset)
           Result->Provenance[BitIdx] = B->Provenance[BitIdx];

llvm/lib/Transforms/Utils/LoopPeel.cpp

@@ -165,7 +165,7 @@ public:
 
 protected:
   using PeelCounter = std::optional<unsigned>;
-  const PeelCounter Unknown = None;
+  const PeelCounter Unknown = std::nullopt;
 
   // Add 1 respecting Unknown and return Unknown if result over MaxIterations
   PeelCounter addOne(PeelCounter PC) const {
@@ -250,7 +250,7 @@ Optional<unsigned> PhiAnalyzer::calculateIterationsToPeel() {
     }
   }
   assert((Iterations <= MaxIterations) && "bad result in phi analysis");
-  return Iterations ? Optional<unsigned>(Iterations) : None;
+  return Iterations ? Optional<unsigned>(Iterations) : std::nullopt;
 }
 
 } // unnamed namespace

llvm/lib/Transforms/Utils/LoopUnroll.cpp

@@ -703,7 +703,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
     if (CompletelyUnroll) {
       if (PreserveOnlyFirst) {
         if (i == 0)
-          return None;
+          return std::nullopt;
         return j == 0;
       }
       // Complete (but possibly inexact) unrolling
@@ -711,7 +711,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
         return true;
       if (Info.TripCount && j != Info.TripCount)
         return false;
-      return None;
+      return std::nullopt;
     }
 
     if (ULO.Runtime) {
@@ -719,7 +719,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
       // exits may be stale.
       if (IsLatch && j != 0)
         return false;
-      return None;
+      return std::nullopt;
     }
 
     if (j != Info.BreakoutTrip &&
@@ -728,7 +728,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI,
       // unconditional branch for some iterations.
       return false;
     }
-    return None;
+    return std::nullopt;
   };
 
   // Fold branches for iterations where we know that they will exit or not

llvm/lib/Transforms/Utils/LoopUtils.cpp

@@ -258,7 +258,7 @@ llvm::getOptionalElementCountLoopAttribute(const Loop *TheLoop) {
     return ElementCount::get(*Width, IsScalable.value_or(false));
   }
 
-  return None;
+  return std::nullopt;
 }
 
 Optional<MDNode *> llvm::makeFollowupLoopID(
@@ -267,7 +267,7 @@ Optional<MDNode *> llvm::makeFollowupLoopID(
   if (!OrigLoopID) {
     if (AlwaysNew)
       return nullptr;
-    return None;
+    return std::nullopt;
   }
 
   assert(OrigLoopID->getOperand(0) == OrigLoopID);
@@ -326,7 +326,7 @@ Optional<MDNode *> llvm::makeFollowupLoopID(
   // Attributes of the followup loop not specified explicity, so signal to the
   // transformation pass to add suitable attributes.
   if (!AlwaysNew && !HasAnyFollowup)
-    return None;
+    return std::nullopt;
 
   // If no attributes were added or remove, the previous loop Id can be reused.
   if (!AlwaysNew && !Changed)
@@ -790,14 +790,14 @@ getEstimatedTripCount(BranchInst *ExitingBranch, Loop *L,
   // we exited the loop.
   uint64_t LoopWeight, ExitWeight;
   if (!extractBranchWeights(*ExitingBranch, LoopWeight, ExitWeight))
-    return None;
+    return std::nullopt;
 
   if (L->contains(ExitingBranch->getSuccessor(1)))
     std::swap(LoopWeight, ExitWeight);
 
   if (!ExitWeight)
     // Don't have a way to return predicated infinite
-    return None;
+    return std::nullopt;
 
   OrigExitWeight = ExitWeight;
 
@@ -824,7 +824,7 @@ llvm::getLoopEstimatedTripCount(Loop *L,
       return *EstTripCount;
     }
   }
-  return None;
+  return std::nullopt;
 }
 
 bool llvm::setLoopEstimatedTripCount(Loop *L, unsigned EstimatedTripCount,

llvm/lib/Transforms/Utils/MemoryOpRemark.cpp

@@ -146,7 +146,7 @@ static void inlineVolatileOrAtomicWithExtraArgs(bool *Inline, bool Volatile,
 
 static Optional<uint64_t> getSizeInBytes(Optional<uint64_t> SizeInBits) {
   if (!SizeInBits || *SizeInBits % 8 != 0)
-    return None;
+    return std::nullopt;
   return *SizeInBits / 8;
 }
 
@@ -300,7 +300,7 @@ void MemoryOpRemark::visitSizeOperand(Value *V, DiagnosticInfoIROptimization &R)
 static Optional<StringRef> nameOrNone(const Value *V) {
   if (V->hasName())
     return V->getName();
-  return None;
+  return std::nullopt;
 }
 
 void MemoryOpRemark::visitVariable(const Value *V,
@@ -341,7 +341,7 @@ void MemoryOpRemark::visitVariable(const Value *V,
   // If not, get it from the alloca.
   Optional<TypeSize> TySize = AI->getAllocationSizeInBits(DL);
   Optional<uint64_t> Size =
-      TySize ? getSizeInBytes(TySize->getFixedSize()) : None;
+      TySize ? getSizeInBytes(TySize->getFixedSize()) : std::nullopt;
   VariableInfo Var{nameOrNone(AI), Size};
   if (!Var.isEmpty())
     Result.push_back(std::move(Var));
@@ -361,7 +361,7 @@ void MemoryOpRemark::visitPtr(Value *Ptr, bool IsRead, DiagnosticInfoIROptimizat
     uint64_t Size = Ptr->getPointerDereferenceableBytes(DL, CanBeNull, CanBeFreed);
     if (!Size)
       return;
-    VIs.push_back({None, Size});
+    VIs.push_back({std::nullopt, Size});
   }
 
   R << (IsRead ? "\n Read Variables: " : "\n Written Variables: ");

llvm/lib/Transforms/Utils/PredicateInfo.cpp

@@ -800,7 +800,7 @@ Optional<PredicateConstraint> PredicateBase::getConstraint() const {
     CmpInst *Cmp = dyn_cast<CmpInst>(Condition);
     if (!Cmp) {
       // TODO: Make this an assertion once RenamedOp is fully accurate.
-      return None;
+      return std::nullopt;
     }
 
     CmpInst::Predicate Pred;
@@ -813,7 +813,7 @@ Optional<PredicateConstraint> PredicateBase::getConstraint() const {
       OtherOp = Cmp->getOperand(0);
     } else {
       // TODO: Make this an assertion once RenamedOp is fully accurate.
-      return None;
+      return std::nullopt;
     }
 
     // Invert predicate along false edge.
@@ -825,7 +825,7 @@ Optional<PredicateConstraint> PredicateBase::getConstraint() const {
   case PT_Switch:
     if (Condition != RenamedOp) {
       // TODO: Make this an assertion once RenamedOp is fully accurate.
-      return None;
+      return std::nullopt;
     }
 
     return {{CmpInst::ICMP_EQ, cast<PredicateSwitch>(this)->CaseValue}};

llvm/lib/Transforms/Utils/SimplifyCFG.cpp

@@ -3267,7 +3267,7 @@ FoldCondBranchOnValueKnownInPredecessorImpl(BranchInst *BI, DomTreeUpdater *DTU,
     MergeBlockIntoPredecessor(EdgeBB, DTU);
 
     // Signal repeat, simplifying any other constants.
-    return None;
+    return std::nullopt;
   }
 
   return false;
@@ -3282,8 +3282,8 @@ static bool FoldCondBranchOnValueKnownInPredecessor(BranchInst *BI,
   do {
     // Note that None means "we changed things, but recurse further."
     Result = FoldCondBranchOnValueKnownInPredecessorImpl(BI, DTU, DL, AC);
-    EverChanged |= Result == None || *Result;
+    EverChanged |= Result == std::nullopt || *Result;
-  } while (Result == None);
+  } while (Result == std::nullopt);
   return EverChanged;
 }
 
@@ -3558,7 +3558,7 @@ shouldFoldCondBranchesToCommonDestination(BranchInst *BI, BranchInst *PBI,
     if (PBITrueProb.isUnknown() || PBITrueProb.getCompl() < Likely)
       return {{Instruction::Or, true}};
   }
-  return None;
+  return std::nullopt;
 }
 
 static bool performBranchToCommonDestFolding(BranchInst *BI, BranchInst *PBI,

llvm/lib/Transforms/Utils/SimplifyIndVar.cpp

@@ -1042,9 +1042,8 @@ class WidenIV {
                                               Instruction *UseI) {
     DefUserPair Key(Def, UseI);
     auto It = PostIncRangeInfos.find(Key);
-    return It == PostIncRangeInfos.end()
+    return It == PostIncRangeInfos.end() ? Optional<ConstantRange>(std::nullopt)
-               ? Optional<ConstantRange>(None)
+                                         : Optional<ConstantRange>(It->second);
-               : Optional<ConstantRange>(It->second);
   }
 
   void calculatePostIncRanges(PHINode *OrigPhi);

llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp

@@ -3855,7 +3855,7 @@ Value *FortifiedLibCallSimplifier::optimizeStrpCpyChk(CallInst *CI,
   // st[rp]cpy_chk call which may fail at runtime if the size is too long.
   // TODO: It might be nice to get a maximum length out of the possible
   // string lengths for varying.
-  if (isFortifiedCallFoldable(CI, 2, None, 1)) {
+  if (isFortifiedCallFoldable(CI, 2, std::nullopt, 1)) {
     if (Func == LibFunc_strcpy_chk)
       return copyFlags(*CI, emitStrCpy(Dst, Src, B, TLI));
     else
@@ -3886,7 +3886,7 @@ Value *FortifiedLibCallSimplifier::optimizeStrpCpyChk(CallInst *CI,
 
 Value *FortifiedLibCallSimplifier::optimizeStrLenChk(CallInst *CI,
                                                      IRBuilderBase &B) {
-  if (isFortifiedCallFoldable(CI, 1, None, 0))
+  if (isFortifiedCallFoldable(CI, 1, std::nullopt, 0))
     return copyFlags(*CI, emitStrLen(CI->getArgOperand(0), B,
                                      CI->getModule()->getDataLayout(), TLI));
   return nullptr;
@@ -3921,7 +3921,7 @@ Value *FortifiedLibCallSimplifier::optimizeMemCCpyChk(CallInst *CI,
 
 Value *FortifiedLibCallSimplifier::optimizeSNPrintfChk(CallInst *CI,
                                                        IRBuilderBase &B) {
-  if (isFortifiedCallFoldable(CI, 3, 1, None, 2)) {
+  if (isFortifiedCallFoldable(CI, 3, 1, std::nullopt, 2)) {
     SmallVector<Value *, 8> VariadicArgs(drop_begin(CI->args(), 5));
     return copyFlags(*CI,
                      emitSNPrintf(CI->getArgOperand(0), CI->getArgOperand(1),
@@ -3933,7 +3933,7 @@ Value *FortifiedLibCallSimplifier::optimizeSNPrintfChk(CallInst *CI,
 
 Value *FortifiedLibCallSimplifier::optimizeSPrintfChk(CallInst *CI,
                                                       IRBuilderBase &B) {
-  if (isFortifiedCallFoldable(CI, 2, None, None, 1)) {
+  if (isFortifiedCallFoldable(CI, 2, std::nullopt, std::nullopt, 1)) {
     SmallVector<Value *, 8> VariadicArgs(drop_begin(CI->args(), 4));
     return copyFlags(*CI,
                      emitSPrintf(CI->getArgOperand(0), CI->getArgOperand(3),
@@ -3984,7 +3984,7 @@ Value *FortifiedLibCallSimplifier::optimizeStrLCpyChk(CallInst *CI,
 
 Value *FortifiedLibCallSimplifier::optimizeVSNPrintfChk(CallInst *CI,
                                                         IRBuilderBase &B) {
-  if (isFortifiedCallFoldable(CI, 3, 1, None, 2))
+  if (isFortifiedCallFoldable(CI, 3, 1, std::nullopt, 2))
     return copyFlags(
         *CI, emitVSNPrintf(CI->getArgOperand(0), CI->getArgOperand(1),
                            CI->getArgOperand(4), CI->getArgOperand(5), B, TLI));
@@ -3994,7 +3994,7 @@ Value *FortifiedLibCallSimplifier::optimizeVSNPrintfChk(CallInst *CI,
 
 Value *FortifiedLibCallSimplifier::optimizeVSPrintfChk(CallInst *CI,
                                                        IRBuilderBase &B) {
-  if (isFortifiedCallFoldable(CI, 2, None, None, 1))
+  if (isFortifiedCallFoldable(CI, 2, std::nullopt, std::nullopt, 1))
     return copyFlags(*CI,
                      emitVSPrintf(CI->getArgOperand(0), CI->getArgOperand(3),
                                   CI->getArgOperand(4), B, TLI));

llvm/lib/Transforms/Utils/ValueMapper.cpp

@@ -391,8 +391,9 @@ Value *Mapper::mapValue(const Value *V) {
       // ensures metadata operands only reference defined SSA values.
       return (Flags & RF_IgnoreMissingLocals)
                  ? nullptr
-                 : MetadataAsValue::get(V->getContext(),
+                 : MetadataAsValue::get(
-                                        MDTuple::get(V->getContext(), None));
+                       V->getContext(),
+                       MDTuple::get(V->getContext(), std::nullopt));
     }
     if (auto *AL = dyn_cast<DIArgList>(MD)) {
       SmallVector<ValueAsMetadata *, 4> MappedArgs;
@@ -578,7 +579,7 @@ Optional<Metadata *> MDNodeMapper::tryToMapOperand(const Metadata *Op) {
   const MDNode &N = *cast<MDNode>(Op);
   if (N.isDistinct())
     return mapDistinctNode(N);
-  return None;
+  return std::nullopt;
 }
 
 MDNode *MDNodeMapper::mapDistinctNode(const MDNode &N) {
@@ -619,7 +620,7 @@ Optional<Metadata *> MDNodeMapper::getMappedOp(const Metadata *Op) const {
   if (auto *CMD = dyn_cast<ConstantAsMetadata>(Op))
     return wrapConstantAsMetadata(*CMD, M.getVM().lookup(CMD->getValue()));
 
-  return None;
+  return std::nullopt;
 }
 
 Metadata &MDNodeMapper::UniquedGraph::getFwdReference(MDNode &Op) {
@@ -848,7 +849,7 @@ Optional<Metadata *> Mapper::mapSimpleMetadata(const Metadata *MD) {
 
   assert(isa<MDNode>(MD) && "Expected a metadata node");
 
-  return None;
+  return std::nullopt;
 }
 
 Metadata *Mapper::mapMetadata(const Metadata *MD) {

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -417,7 +417,7 @@ static Optional<unsigned> getSmallBestKnownTC(ScalarEvolution &SE, Loop *L) {
   if (unsigned ExpectedTC = SE.getSmallConstantMaxTripCount(L))
     return ExpectedTC;
 
-  return None;
+  return std::nullopt;
 }
 
 // Forward declare GeneratedRTChecks.
@@ -6452,8 +6452,8 @@ LoopVectorizationCostModel::getConsecutiveMemOpCost(Instruction *I,
 
   bool Reverse = ConsecutiveStride < 0;
   if (Reverse)
-    Cost += TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, VectorTy, None,
+    Cost += TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, VectorTy,
-                               CostKind, 0);
+                               std::nullopt, CostKind, 0);
   return Cost;
 }
 
@@ -6537,8 +6537,8 @@ LoopVectorizationCostModel::getInterleaveGroupCost(Instruction *I,
     assert(!Legal->isMaskRequired(I) &&
            "Reverse masked interleaved access not supported.");
     Cost += Group->getNumMembers() *
-            TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, VectorTy, None,
+            TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, VectorTy,
-                               CostKind, 0);
+                               std::nullopt, CostKind, 0);
   }
   return Cost;
 }
@@ -6548,7 +6548,7 @@ Optional<InstructionCost> LoopVectorizationCostModel::getReductionPatternCost(
   using namespace llvm::PatternMatch;
   // Early exit for no inloop reductions
   if (InLoopReductionChains.empty() || VF.isScalar() || !isa<VectorType>(Ty))
-    return None;
+    return std::nullopt;
   auto *VectorTy = cast<VectorType>(Ty);
 
   // We are looking for a pattern of, and finding the minimal acceptable cost:
@@ -6566,7 +6566,7 @@ Optional<InstructionCost> LoopVectorizationCostModel::getReductionPatternCost(
   Instruction *RetI = I;
   if (match(RetI, m_ZExtOrSExt(m_Value()))) {
     if (!RetI->hasOneUser())
-      return None;
+      return std::nullopt;
     RetI = RetI->user_back();
   }
 
@@ -6578,7 +6578,7 @@ Optional<InstructionCost> LoopVectorizationCostModel::getReductionPatternCost(
   // Test if the found instruction is a reduction, and if not return an invalid
   // cost specifying the parent to use the original cost modelling.
   if (!InLoopReductionImmediateChains.count(RetI))
-    return None;
+    return std::nullopt;
 
   // Find the reduction this chain is a part of and calculate the basic cost of
   // the reduction on its own.
@@ -6712,7 +6712,7 @@ Optional<InstructionCost> LoopVectorizationCostModel::getReductionPatternCost(
     }
   }
 
-  return I == RetI ? Optional<InstructionCost>(BaseCost) : None;
+  return I == RetI ? Optional<InstructionCost>(BaseCost) : std::nullopt;
 }
 
 InstructionCost
@@ -7498,7 +7498,7 @@ LoopVectorizationPlanner::plan(ElementCount UserVF, unsigned UserIC) {
   assert(OrigLoop->isInnermost() && "Inner loop expected.");
   FixedScalableVFPair MaxFactors = CM.computeMaxVF(UserVF, UserIC);
   if (!MaxFactors) // Cases that should not to be vectorized nor interleaved.
-    return None;
+    return std::nullopt;
 
   // Invalidate interleave groups if all blocks of loop will be predicated.
   if (CM.blockNeedsPredicationForAnyReason(OrigLoop->getHeader()) &&

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -293,12 +293,12 @@ static Optional<unsigned> getInsertIndex(const Value *InsertInst,
   if (const auto *IE = dyn_cast<InsertElementInst>(InsertInst)) {
     const auto *VT = dyn_cast<FixedVectorType>(IE->getType());
     if (!VT)
-      return None;
+      return std::nullopt;
     const auto *CI = dyn_cast<ConstantInt>(IE->getOperand(2));
     if (!CI)
-      return None;
+      return std::nullopt;
     if (CI->getValue().uge(VT->getNumElements()))
-      return None;
+      return std::nullopt;
     Index *= VT->getNumElements();
     Index += CI->getZExtValue();
     return Index;
@@ -314,7 +314,7 @@ static Optional<unsigned> getInsertIndex(const Value *InsertInst,
       Index *= AT->getNumElements();
       CurrentType = AT->getElementType();
     } else {
-      return None;
+      return std::nullopt;
     }
     Index += I;
   }
@@ -326,7 +326,7 @@ static Optional<unsigned> getInsertIndex(const Value *InsertInst,
 /// elements actually mask the insertelement buildvector, if any.
 template <bool IsPoisonOnly = false>
 static SmallBitVector isUndefVector(const Value *V,
-                                    ArrayRef<int> ShuffleMask = None) {
+                                    ArrayRef<int> ShuffleMask = std::nullopt) {
   SmallBitVector Res(ShuffleMask.empty() ? 1 : ShuffleMask.size(), true);
   using T = std::conditional_t<IsPoisonOnly, PoisonValue, UndefValue>;
   if (isa<T>(V))
@@ -417,10 +417,10 @@ isFixedVectorShuffle(ArrayRef<Value *> VL, SmallVectorImpl<int> &Mask) {
   const auto *It =
       find_if(VL, [](Value *V) { return isa<ExtractElementInst>(V); });
   if (It == VL.end())
-    return None;
+    return std::nullopt;
   auto *EI0 = cast<ExtractElementInst>(*It);
   if (isa<ScalableVectorType>(EI0->getVectorOperandType()))
-    return None;
+    return std::nullopt;
   unsigned Size =
       cast<FixedVectorType>(EI0->getVectorOperandType())->getNumElements();
   Value *Vec1 = nullptr;
@@ -434,19 +434,19 @@ isFixedVectorShuffle(ArrayRef<Value *> VL, SmallVectorImpl<int> &Mask) {
       continue;
     auto *EI = cast<ExtractElementInst>(VL[I]);
     if (isa<ScalableVectorType>(EI->getVectorOperandType()))
-      return None;
+      return std::nullopt;
     auto *Vec = EI->getVectorOperand();
     // We can extractelement from undef or poison vector.
     if (isUndefVector(Vec).all())
       continue;
     // All vector operands must have the same number of vector elements.
     if (cast<FixedVectorType>(Vec->getType())->getNumElements() != Size)
-      return None;
+      return std::nullopt;
     if (isa<UndefValue>(EI->getIndexOperand()))
       continue;
     auto *Idx = dyn_cast<ConstantInt>(EI->getIndexOperand());
     if (!Idx)
-      return None;
+      return std::nullopt;
     // Undefined behavior if Idx is negative or >= Size.
     if (Idx->getValue().uge(Size))
       continue;
@@ -460,7 +460,7 @@ isFixedVectorShuffle(ArrayRef<Value *> VL, SmallVectorImpl<int> &Mask) {
       Vec2 = Vec;
       Mask[I] += Size;
     } else {
-      return None;
+      return std::nullopt;
     }
     if (CommonShuffleMode == Permute)
       continue;
@@ -737,12 +737,12 @@ static Optional<unsigned> getExtractIndex(Instruction *E) {
   if (Opcode == Instruction::ExtractElement) {
     auto *CI = dyn_cast<ConstantInt>(E->getOperand(1));
     if (!CI)
-      return None;
+      return std::nullopt;
     return CI->getZExtValue();
   }
   ExtractValueInst *EI = cast<ExtractValueInst>(E);
   if (EI->getNumIndices() != 1)
-    return None;
+    return std::nullopt;
   return *EI->idx_begin();
 }
 
@@ -980,7 +980,7 @@ public:
 
   /// \returns the vectorization cost of the subtree that starts at \p VL.
   /// A negative number means that this is profitable.
-  InstructionCost getTreeCost(ArrayRef<Value *> VectorizedVals = None);
+  InstructionCost getTreeCost(ArrayRef<Value *> VectorizedVals = std::nullopt);
 
   /// Construct a vectorizable tree that starts at \p Roots, ignoring users for
   /// the purpose of scheduling and extraction in the \p UserIgnoreLst.
@@ -1420,7 +1420,7 @@ public:
           // Recursively calculate the cost at each level
           int TmpScore =
               getScoreAtLevelRec(I1->getOperand(OpIdx1), I2->getOperand(OpIdx2),
-                                 I1, I2, CurrLevel + 1, None);
+                                 I1, I2, CurrLevel + 1, std::nullopt);
           // Look for the best score.
           if (TmpScore > LookAheadHeuristics::ScoreFail &&
               TmpScore > MaxTmpScore) {
@@ -1585,7 +1585,7 @@ public:
       auto *IdxLaneI = dyn_cast<Instruction>(IdxLaneV);
       if (!IdxLaneI || !isa<Instruction>(OpIdxLaneV))
         return 0;
-      return R.areAllUsersVectorized(IdxLaneI, None)
+      return R.areAllUsersVectorized(IdxLaneI, std::nullopt)
                  ? LookAheadHeuristics::ScoreAllUserVectorized
                  : 0;
     }
@@ -1653,7 +1653,7 @@ public:
       // Our strategy mode for OpIdx.
       ReorderingMode RMode = ReorderingModes[OpIdx];
       if (RMode == ReorderingMode::Failed)
-        return None;
+        return std::nullopt;
 
       // The linearized opcode of the operand at OpIdx, Lane.
       bool OpIdxAPO = getData(OpIdx, Lane).APO;
@@ -1662,7 +1662,7 @@ public:
       // Sometimes we have more than one option (e.g., Opcode and Undefs), so we
       // are using the score to differentiate between the two.
       struct BestOpData {
-        Optional<unsigned> Idx = None;
+        Optional<unsigned> Idx = std::nullopt;
         unsigned Score = 0;
       } BestOp;
       BestOp.Score =
@@ -1722,7 +1722,7 @@ public:
         return BestOp.Idx;
       }
       // If we could not find a good match return None.
-      return None;
+      return std::nullopt;
     }
 
     /// Helper for reorderOperandVecs.
@@ -2153,7 +2153,7 @@ public:
       int Score = LookAhead.getScoreAtLevelRec(Candidates[I].first,
                                                Candidates[I].second,
                                                /*U1=*/nullptr, /*U2=*/nullptr,
-                                               /*Level=*/1, None);
+                                               /*Level=*/1, std::nullopt);
       if (Score > BestScore) {
         BestScore = Score;
         Index = I;
@@ -2655,8 +2655,8 @@ private:
   TreeEntry *newTreeEntry(ArrayRef<Value *> VL, Optional<ScheduleData *> Bundle,
                           const InstructionsState &S,
                           const EdgeInfo &UserTreeIdx,
-                          ArrayRef<int> ReuseShuffleIndices = None,
+                          ArrayRef<int> ReuseShuffleIndices = std::nullopt,
-                          ArrayRef<unsigned> ReorderIndices = None) {
+                          ArrayRef<unsigned> ReorderIndices = std::nullopt) {
     TreeEntry::EntryState EntryState =
         Bundle ? TreeEntry::Vectorize : TreeEntry::NeedToGather;
     return newTreeEntry(VL, EntryState, Bundle, S, UserTreeIdx,
@@ -2668,8 +2668,8 @@ private:
                           Optional<ScheduleData *> Bundle,
                           const InstructionsState &S,
                           const EdgeInfo &UserTreeIdx,
-                          ArrayRef<int> ReuseShuffleIndices = None,
+                          ArrayRef<int> ReuseShuffleIndices = std::nullopt,
-                          ArrayRef<unsigned> ReorderIndices = None) {
+                          ArrayRef<unsigned> ReorderIndices = std::nullopt) {
     assert(((!Bundle && EntryState == TreeEntry::NeedToGather) ||
             (Bundle && EntryState != TreeEntry::NeedToGather)) &&
            "Need to vectorize gather entry?");
@@ -3580,11 +3580,11 @@ BoUpSLP::findReusedOrderedScalars(const BoUpSLP::TreeEntry &TE) {
         STE = LocalSTE;
       else if (STE != LocalSTE)
         // Take the order only from the single vector node.
-        return None;
+        return std::nullopt;
       unsigned Lane =
           std::distance(STE->Scalars.begin(), find(STE->Scalars, V));
       if (Lane >= NumScalars)
-        return None;
+        return std::nullopt;
       if (CurrentOrder[Lane] != NumScalars) {
         if (Lane != I)
           continue;
@@ -3623,7 +3623,7 @@ BoUpSLP::findReusedOrderedScalars(const BoUpSLP::TreeEntry &TE) {
     }
     return CurrentOrder;
   }
-  return None;
+  return std::nullopt;
 }
 
 namespace {
@@ -3808,14 +3808,14 @@ BoUpSLP::findPartiallyOrderedLoads(const BoUpSLP::TreeEntry &TE) {
   for (Value *V : TE.Scalars) {
     auto *L = dyn_cast<LoadInst>(V);
     if (!L || !L->isSimple())
-      return None;
+      return std::nullopt;
     Ptrs.push_back(L->getPointerOperand());
   }
 
   BoUpSLP::OrdersType Order;
   if (clusterSortPtrAccesses(Ptrs, ScalarTy, *DL, *SE, Order))
     return Order;
-  return None;
+  return std::nullopt;
 }
 
 /// Check if two insertelement instructions are from the same buildvector.
@@ -3835,7 +3835,7 @@ static bool areTwoInsertFromSameBuildVector(
   auto *IE2 = V;
   Optional<unsigned> Idx1 = getInsertIndex(IE1);
   Optional<unsigned> Idx2 = getInsertIndex(IE2);
-  if (Idx1 == None || Idx2 == None)
+  if (Idx1 == std::nullopt || Idx2 == std::nullopt)
     return false;
   // Go through the vector operand of insertelement instructions trying to find
   // either VU as the original vector for IE2 or V as the original vector for
@@ -3878,7 +3878,7 @@ Optional<BoUpSLP::OrdersType> BoUpSLP::getReorderingData(const TreeEntry &TE,
     unsigned Sz = TE.Scalars.size();
     if (!ShuffleVectorInst::isOneUseSingleSourceMask(TE.ReuseShuffleIndices,
                                                      Sz))
-      return None;
+      return std::nullopt;
     unsigned VF = TE.getVectorFactor();
     // Try build correct order for extractelement instructions.
     SmallVector<int> ReusedMask(TE.ReuseShuffleIndices.begin(),
@@ -3940,7 +3940,7 @@ Optional<BoUpSLP::OrdersType> BoUpSLP::getReorderingData(const TreeEntry &TE,
             return false;
           Optional<unsigned> Idx1 = getInsertIndex(IE1);
           Optional<unsigned> Idx2 = getInsertIndex(IE2);
-          if (Idx1 == None || Idx2 == None)
+          if (Idx1 == std::nullopt || Idx2 == std::nullopt)
             return false;
           return *Idx1 < *Idx2;
         }
@@ -3950,7 +3950,7 @@ Optional<BoUpSLP::OrdersType> BoUpSLP::getReorderingData(const TreeEntry &TE,
             return false;
           Optional<unsigned> Idx1 = getExtractIndex(EE1);
           Optional<unsigned> Idx2 = getExtractIndex(EE2);
-          if (Idx1 == None || Idx2 == None)
+          if (Idx1 == std::nullopt || Idx2 == std::nullopt)
             return false;
           return *Idx1 < *Idx2;
         }
@@ -4011,7 +4011,7 @@ Optional<BoUpSLP::OrdersType> BoUpSLP::getReorderingData(const TreeEntry &TE,
       if (Optional<OrdersType> Order = findPartiallyOrderedLoads(TE))
         return Order;
   }
-  return None;
+  return std::nullopt;
 }
 
 /// Checks if the given mask is a "clustered" mask with the same clusters of
@@ -4961,7 +4961,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
                                                  })) ||
           !llvm::isPowerOf2_32(NumUniqueScalarValues)) {
         LLVM_DEBUG(dbgs() << "SLP: Scalar used twice in bundle.\n");
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
         return false;
       }
       VL = UniqueValues;
@@ -4985,7 +4985,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
          })))) {
     LLVM_DEBUG(dbgs() << "SLP: Gathering due to max recursion depth.\n");
     if (TryToFindDuplicates(S))
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                    ReuseShuffleIndicies);
     return;
   }
@@ -4996,7 +4996,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
           cast<ExtractElementInst>(S.OpValue)->getVectorOperandType())) {
     LLVM_DEBUG(dbgs() << "SLP: Gathering due to scalable vector type.\n");
     if (TryToFindDuplicates(S))
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                    ReuseShuffleIndicies);
     return;
   }
@@ -5005,14 +5005,14 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
   if (S.OpValue->getType()->isVectorTy() &&
       !isa<InsertElementInst>(S.OpValue)) {
     LLVM_DEBUG(dbgs() << "SLP: Gathering due to vector type.\n");
-    newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+    newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
     return;
   }
 
   if (StoreInst *SI = dyn_cast<StoreInst>(S.OpValue))
     if (SI->getValueOperand()->getType()->isVectorTy()) {
       LLVM_DEBUG(dbgs() << "SLP: Gathering due to store vector type.\n");
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
       return;
     }
 
@@ -5100,7 +5100,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       NotProfitableForVectorization(VL)) {
     LLVM_DEBUG(dbgs() << "SLP: Gathering due to C,S,B,O, small shuffle. \n");
     if (TryToFindDuplicates(S))
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                    ReuseShuffleIndicies);
     return;
   }
@@ -5114,7 +5114,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       if (EphValues.count(V)) {
         LLVM_DEBUG(dbgs() << "SLP: The instruction (" << *V
                           << ") is ephemeral.\n");
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
         return;
       }
     }
@@ -5126,7 +5126,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
     if (!E->isSame(VL)) {
       LLVM_DEBUG(dbgs() << "SLP: Gathering due to partial overlap.\n");
       if (TryToFindDuplicates(S))
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
       return;
     }
@@ -5146,7 +5146,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       LLVM_DEBUG(dbgs() << "SLP: The instruction (" << *V
                         << ") is already in tree.\n");
       if (TryToFindDuplicates(S))
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
       return;
     }
@@ -5158,7 +5158,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       if (UserIgnoreList && UserIgnoreList->contains(V)) {
         LLVM_DEBUG(dbgs() << "SLP: Gathering due to gathered scalar.\n");
         if (TryToFindDuplicates(S))
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
         return;
       }
@@ -5189,7 +5189,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
     // Don't go into unreachable blocks. They may contain instructions with
     // dependency cycles which confuse the final scheduling.
     LLVM_DEBUG(dbgs() << "SLP: bundle in unreachable block.\n");
-    newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+    newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
     return;
   }
 
@@ -5198,7 +5198,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
   // place to insert a shuffle if we need to, so just avoid that issue.
   if (isa<CatchSwitchInst>(BB->getTerminator())) {
     LLVM_DEBUG(dbgs() << "SLP: bundle in catchswitch block.\n");
-    newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+    newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
     return;
   }
 
@@ -5222,7 +5222,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
     assert((!BS.getScheduleData(VL0) ||
             !BS.getScheduleData(VL0)->isPartOfBundle()) &&
            "tryScheduleBundle should cancelScheduling on failure");
-    newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+    newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                  ReuseShuffleIndicies);
     return;
   }
@@ -5242,7 +5242,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
             LLVM_DEBUG(dbgs()
                        << "SLP: Need to swizzle PHINodes (terminator use).\n");
             BS.cancelScheduling(VL, VL0);
-            newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+            newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                          ReuseShuffleIndicies);
             return;
           }
@@ -5309,7 +5309,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         return;
       }
       LLVM_DEBUG(dbgs() << "SLP: Gather extract sequence.\n");
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                    ReuseShuffleIndicies);
       BS.cancelScheduling(VL, VL0);
       return;
@@ -5322,7 +5322,8 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       ValueSet SourceVectors;
       for (Value *V : VL) {
         SourceVectors.insert(cast<Instruction>(V)->getOperand(0));
-        assert(getInsertIndex(V) != None && "Non-constant or undef index?");
+        assert(getInsertIndex(V) != std::nullopt &&
+               "Non-constant or undef index?");
       }
 
       if (count_if(VL, [&SourceVectors](Value *V) {
@@ -5331,7 +5332,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         // Found 2nd source vector - cancel.
         LLVM_DEBUG(dbgs() << "SLP: Gather of insertelement vectors with "
                              "different source vectors.\n");
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx);
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx);
         BS.cancelScheduling(VL, VL0);
         return;
       }
@@ -5357,7 +5358,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       if (IsIdentity)
         CurrentOrder.clear();
       TreeEntry *TE = newTreeEntry(VL, Bundle /*vectorized*/, S, UserTreeIdx,
-                                   None, CurrentOrder);
+                                   std::nullopt, CurrentOrder);
       LLVM_DEBUG(dbgs() << "SLP: added inserts bundle.\n");
 
       constexpr int NumOps = 2;
@@ -5408,7 +5409,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         break;
       case LoadsState::Gather:
         BS.cancelScheduling(VL, VL0);
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
 #ifndef NDEBUG
         Type *ScalarTy = VL0->getType();
@@ -5443,7 +5444,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         Type *Ty = cast<Instruction>(V)->getOperand(0)->getType();
         if (Ty != SrcTy || !isValidElementType(Ty)) {
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           LLVM_DEBUG(dbgs()
                      << "SLP: Gathering casts with different src types.\n");
@@ -5476,7 +5477,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         if ((Cmp->getPredicate() != P0 && Cmp->getPredicate() != SwapP0) ||
             Cmp->getOperand(0)->getType() != ComparedTy) {
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           LLVM_DEBUG(dbgs()
                      << "SLP: Gathering cmp with different predicate.\n");
@@ -5568,7 +5569,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         if (I->getNumOperands() != 2) {
           LLVM_DEBUG(dbgs() << "SLP: not-vectorizable GEP (nested indexes).\n");
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           return;
         }
@@ -5586,7 +5587,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
           LLVM_DEBUG(dbgs()
                      << "SLP: not-vectorizable GEP (different types).\n");
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           return;
         }
@@ -5608,7 +5609,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
           LLVM_DEBUG(dbgs()
                      << "SLP: not-vectorizable GEP (non-constant indexes).\n");
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           return;
         }
@@ -5676,7 +5677,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       if (DL->getTypeSizeInBits(ScalarTy) !=
           DL->getTypeAllocSizeInBits(ScalarTy)) {
         BS.cancelScheduling(VL, VL0);
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
         LLVM_DEBUG(dbgs() << "SLP: Gathering stores of non-packed type.\n");
         return;
@@ -5691,7 +5692,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         auto *SI = cast<StoreInst>(V);
         if (!SI->isSimple()) {
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           LLVM_DEBUG(dbgs() << "SLP: Gathering non-simple stores.\n");
           return;
@@ -5739,7 +5740,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       }
 
       BS.cancelScheduling(VL, VL0);
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                    ReuseShuffleIndicies);
       LLVM_DEBUG(dbgs() << "SLP: Non-consecutive store.\n");
       return;
@@ -5757,7 +5758,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
 
       if (!VecFunc && !isTriviallyVectorizable(ID)) {
         BS.cancelScheduling(VL, VL0);
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
         LLVM_DEBUG(dbgs() << "SLP: Non-vectorizable call.\n");
         return;
@@ -5776,7 +5777,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
              VecFunc != VFDatabase(*CI2).getVectorizedFunction(Shape)) ||
             !CI->hasIdenticalOperandBundleSchema(*CI2)) {
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           LLVM_DEBUG(dbgs() << "SLP: mismatched calls:" << *CI << "!=" << *V
                             << "\n");
@@ -5789,7 +5790,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
             Value *A1J = CI2->getArgOperand(j);
             if (ScalarArgs[j] != A1J) {
               BS.cancelScheduling(VL, VL0);
-              newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+              newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                            ReuseShuffleIndicies);
               LLVM_DEBUG(dbgs() << "SLP: mismatched arguments in call:" << *CI
                                 << " argument " << ScalarArgs[j] << "!=" << A1J
@@ -5804,7 +5805,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
                         CI->op_begin() + CI->getBundleOperandsEndIndex(),
                         CI2->op_begin() + CI2->getBundleOperandsStartIndex())) {
           BS.cancelScheduling(VL, VL0);
-          newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+          newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                        ReuseShuffleIndicies);
           LLVM_DEBUG(dbgs() << "SLP: mismatched bundle operands in calls:"
                             << *CI << "!=" << *V << '\n');
@@ -5835,7 +5836,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
       // then do not vectorize this instruction.
       if (!S.isAltShuffle()) {
         BS.cancelScheduling(VL, VL0);
-        newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+        newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                      ReuseShuffleIndicies);
         LLVM_DEBUG(dbgs() << "SLP: ShuffleVector are not vectorized.\n");
         return;
@@ -5898,7 +5899,7 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
     }
     default:
       BS.cancelScheduling(VL, VL0);
-      newTreeEntry(VL, None /*not vectorized*/, S, UserTreeIdx,
+      newTreeEntry(VL, std::nullopt /*not vectorized*/, S, UserTreeIdx,
                    ReuseShuffleIndicies);
       LLVM_DEBUG(dbgs() << "SLP: Gathering unknown instruction.\n");
       return;
@@ -6336,20 +6337,22 @@ InstructionCost BoUpSLP::getEntryCost(const TreeEntry *E,
         unsigned Idx = (Data.second / NumElts) * NumElts;
         unsigned EENumElts = EEVTy->getNumElements();
         if (Idx + NumElts <= EENumElts) {
-          Cost += TTI->getShuffleCost(TargetTransformInfo::SK_ExtractSubvector,
+          Cost +=
-                                      EEVTy, None, CostKind, Idx, VecTy);
+              TTI->getShuffleCost(TargetTransformInfo::SK_ExtractSubvector,
+                                  EEVTy, std::nullopt, CostKind, Idx, VecTy);
         } else {
           // Need to round up the subvector type vectorization factor to avoid a
           // crash in cost model functions. Make SubVT so that Idx + VF of SubVT
           // <= EENumElts.
           auto *SubVT =
               FixedVectorType::get(VecTy->getElementType(), EENumElts - Idx);
-          Cost += TTI->getShuffleCost(TargetTransformInfo::SK_ExtractSubvector,
+          Cost +=
-                                      EEVTy, None, CostKind, Idx, SubVT);
+              TTI->getShuffleCost(TargetTransformInfo::SK_ExtractSubvector,
+                                  EEVTy, std::nullopt, CostKind, Idx, SubVT);
         }
       } else {
         Cost += TTI->getShuffleCost(TargetTransformInfo::SK_InsertSubvector,
-                                    VecTy, None, CostKind, 0, EEVTy);
+                                    VecTy, std::nullopt, CostKind, 0, EEVTy);
       }
     }
   };
@@ -6417,7 +6420,7 @@ InstructionCost BoUpSLP::getEntryCost(const TreeEntry *E,
       assert(VecTy == FinalVecTy &&
              "No reused scalars expected for broadcast.");
       return TTI->getShuffleCost(TargetTransformInfo::SK_Broadcast, VecTy,
-                                 /*Mask=*/None, CostKind, /*Index=*/0,
+                                 /*Mask=*/std::nullopt, CostKind, /*Index=*/0,
                                  /*SubTp=*/nullptr, /*Args=*/VL[0]);
     }
     InstructionCost ReuseShuffleCost = 0;
@@ -6507,8 +6510,9 @@ InstructionCost BoUpSLP::getEntryCost(const TreeEntry *E,
         if (NeedInsertSubvectorAnalysis) {
           // Add the cost for the subvectors insert.
           for (int I = VF, E = VL.size(); I < E; I += VF)
-            GatherCost += TTI->getShuffleCost(TTI::SK_InsertSubvector, VecTy,
+            GatherCost +=
-                                              None, CostKind, I, LoadTy);
+                TTI->getShuffleCost(TTI::SK_InsertSubvector, VecTy,
+                                    std::nullopt, CostKind, I, LoadTy);
         }
         return ReuseShuffleCost + GatherCost - ScalarsCost;
       }
@@ -6721,8 +6725,9 @@ InstructionCost BoUpSLP::getEntryCost(const TreeEntry *E,
       if (InsertVecSz != VecSz) {
         auto *ActualVecTy =
             FixedVectorType::get(SrcVecTy->getElementType(), VecSz);
-        Cost += TTI->getShuffleCost(TTI::SK_InsertSubvector, ActualVecTy, None,
+        Cost += TTI->getShuffleCost(TTI::SK_InsertSubvector, ActualVecTy,
-                                    CostKind, OffsetBeg - Offset, InsertVecTy);
+                                    std::nullopt, CostKind, OffsetBeg - Offset,
+                                    InsertVecTy);
       } else {
         for (unsigned I = 0, End = OffsetBeg - Offset; I < End; ++I)
           Mask[I] = InMask.test(I) ? UndefMaskElem : I;
@@ -7693,7 +7698,7 @@ BoUpSLP::isGatherShuffledEntry(const TreeEntry *TE, SmallVectorImpl<int> &Mask,
     if (const TreeEntry *VTE = getTreeEntry(V))
       VToTEs.insert(VTE);
     if (VToTEs.empty())
-      return None;
+      return std::nullopt;
     if (UsedTEs.empty()) {
       // The first iteration, just insert the list of nodes to vector.
       UsedTEs.push_back(VToTEs);
@@ -7722,7 +7727,7 @@ BoUpSLP::isGatherShuffledEntry(const TreeEntry *TE, SmallVectorImpl<int> &Mask,
         // If the number of input vectors is greater than 2 - not a permutation,
         // fallback to the regular gather.
         if (UsedTEs.size() == 2)
-          return None;
+          return std::nullopt;
         UsedTEs.push_back(SavedVToTEs);
         Idx = UsedTEs.size() - 1;
       }
@@ -7733,7 +7738,7 @@ BoUpSLP::isGatherShuffledEntry(const TreeEntry *TE, SmallVectorImpl<int> &Mask,
   if (UsedTEs.empty()) {
     assert(all_of(TE->Scalars, UndefValue::classof) &&
            "Expected vector of undefs only.");
-    return None;
+    return std::nullopt;
   }
 
   unsigned VF = 0;
@@ -7767,7 +7772,7 @@ BoUpSLP::isGatherShuffledEntry(const TreeEntry *TE, SmallVectorImpl<int> &Mask,
     // No 2 source vectors with the same vector factor - give up and do regular
     // gather.
     if (Entries.empty())
-      return None;
+      return std::nullopt;
   }
 
   // Build a shuffle mask for better cost estimation and vector emission.
@@ -7782,7 +7787,7 @@ BoUpSLP::isGatherShuffledEntry(const TreeEntry *TE, SmallVectorImpl<int> &Mask,
     // Extra check required by isSingleSourceMaskImpl function (called by
     // ShuffleVectorInst::isSingleSourceMask).
     if (Mask[I] >= 2 * E)
-      return None;
+      return std::nullopt;
   }
   switch (Entries.size()) {
   case 1:
@@ -7792,7 +7797,7 @@ BoUpSLP::isGatherShuffledEntry(const TreeEntry *TE, SmallVectorImpl<int> &Mask,
   default:
     break;
   }
-  return None;
+  return std::nullopt;
 }
 
 InstructionCost BoUpSLP::getGatherCost(FixedVectorType *Ty,
@@ -9744,7 +9749,7 @@ BoUpSLP::BlockScheduling::tryScheduleBundle(ArrayRef<Value *> VL, BoUpSLP *SLP,
       // dependencies and emit instruction in the wrong order at the actual
       // scheduling.
       TryScheduleBundleImpl(/*ReSchedule=*/false, nullptr);
-      return None;
+      return std::nullopt;
     }
   }
 
@@ -9774,7 +9779,7 @@ BoUpSLP::BlockScheduling::tryScheduleBundle(ArrayRef<Value *> VL, BoUpSLP *SLP,
   TryScheduleBundleImpl(ReSchedule, Bundle);
   if (!Bundle->isReady()) {
     cancelScheduling(VL, S.OpValue);
-    return None;
+    return std::nullopt;
   }
   return Bundle;
 }
@@ -12259,7 +12264,7 @@ static Optional<unsigned> getAggregateSize(Instruction *InsertInst) {
     if (auto *ST = dyn_cast<StructType>(CurrentType)) {
       for (auto *Elt : ST->elements())
         if (Elt != ST->getElementType(0)) // check homogeneity
-          return None;
+          return std::nullopt;
       AggregateSize *= ST->getNumElements();
       CurrentType = ST->getElementType(0);
     } else if (auto *AT = dyn_cast<ArrayType>(CurrentType)) {
@@ -12271,7 +12276,7 @@ static Optional<unsigned> getAggregateSize(Instruction *InsertInst) {
     } else if (CurrentType->isSingleValueType()) {
       return AggregateSize;
     } else {
-      return None;
+      return std::nullopt;
     }
   } while (true);
 }

llvm/lib/Transforms/Vectorize/VPlanSLP.cpp

@@ -193,7 +193,7 @@ static std::optional<unsigned> getOpcode(ArrayRef<VPValue *> Values) {
   if (any_of(Values, [Opcode](VPValue *V) {
         return cast<VPInstruction>(V)->getOpcode() != Opcode;
       }))
-    return None;
+    return std::nullopt;
   return {Opcode};
 }