[Attributor] Deduce memory behavior

[jdoerfert]

Summary

Deduce the memory behavior, aka "read-none", "read-only", or
"write-only", for functions and arguments.

[uenoku]

Overall, I think the logic is sound.

llvm/lib/Transforms/IPO/Attributor.cpp

420

It is based on the explicit rule that SubsumingPositionIterator must iterate the corresponding IRPosition first. I think you should mention this rule somewhere in SubsumingPositionIterator implementation or header.

3228–3230

style: remove bracket

3306–3312

Maybe it is necessary to look at other atomic memory instructions also.

[jdoerfert]

Any other objects or requests?

llvm/lib/Transforms/IPO/Attributor.cpp

420

I will make the behavior of the flag in the header clear and add a comment here.

3228–3230

will do

3306–3312

I will add a TODO. We should eventually have all instructions explicit here.

[uenoku]

In D67384#1675670, @jdoerfert wrote:

Any other objects or requests?

I don't have. It's LGTM.

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

Kind getPositionKind() const {
     return Kind(KindOrArgNo);
   }
 
   /// TODO: Figure out if the attribute related helper functions should live
   ///       here or somewhere else.
 
   /// Return true if any kind in \p AKs existing in the IR at a position that
   /// will affect this one. See also getAttrs(...).
-  bool hasAttr(ArrayRef<Attribute::AttrKind> AKs) const;
+  bool hasAttr(ArrayRef<Attribute::AttrKind> AKs,
+               bool IgnoreSubsumingPositions = false) const;
 
   /// Return the attributes of any kind in \p AKs existing in the IR at a
   /// position that will affect this one. While each position can only have a
   /// single attribute of any kind in \p AKs, there are "subsuming" positions
   /// that could have an attribute as well. This method returns all attributes
   /// found in \p Attrs.
   void getAttrs(ArrayRef<Attribute::AttrKind> AKs,
                 SmallVectorImpl<Attribute> &Attrs) const;
Attribute getAttr(Attribute::AttrKind AK) const {
     else
       AttrList = getAssociatedFunction()->getAttributes();
 
     if (AttrList.hasAttribute(getAttrIdx(), AK))
       return AttrList.getAttribute(getAttrIdx(), AK);
     return Attribute();
   }
 
+  /// Remove the attribute of kind \p AKs existing in the IR at this position.
+  void removeAttrs(ArrayRef<Attribute::AttrKind> AKs) {
+    if (getPositionKind() == IRP_INVALID || getPositionKind() == IRP_FLOAT)
+      return;
+
+    AttributeList AttrList;
+    CallSite CS = CallSite(&getAnchorValue());
+    if (CS)
+      AttrList = CS.getAttributes();
+    else
+      AttrList = getAssociatedFunction()->getAttributes();
+
+    LLVMContext &Ctx = getAnchorValue().getContext();
+    for (Attribute::AttrKind AK : AKs)
+      AttrList = AttrList.removeAttribute(Ctx, getAttrIdx(), AK);
+
+    if (CS)
+      CS.setAttributes(AttrList);
+    else
+      getAssociatedFunction()->setAttributes(AttrList);
+  }
+
   bool isAnyCallSitePosition() const {
     switch (getPositionKind()) {
     case IRPosition::IRP_CALL_SITE:
     case IRPosition::IRP_CALL_SITE_RETURNED:
     case IRPosition::IRP_CALL_SITE_ARGUMENT:
       return true;
     default:
       return false;
struct AANoCapture
 
   /// Create an abstract attribute view for the position \p IRP.
   static AANoCapture &createForPosition(const IRPosition &IRP, Attributor &A);
 
   /// Unique ID (due to the unique address)
   static const char ID;
 };
 
+/// An abstract interface for all nocapture attributes.
+struct AAMemoryBehavior
+    : public IRAttribute<Attribute::ReadNone,
+                         StateWrapper<IntegerState, AbstractAttribute>> {
+  AAMemoryBehavior(const IRPosition &IRP) : IRAttribute(IRP) {}
+
+  /// State encoding bits. A set bit in the state means the property holds.
+  /// BEST_STATE is the best possible state, 0 the worst possible state.
+  enum {
+    NO_READS = 1 << 0,
+    NO_WRITES = 1 << 1,
+    NO_ACCESSES = NO_READS | NO_WRITES,
+
+    BEST_STATE = NO_ACCESSES,
+  };
+
+  /// Return true if we know that the underlying value is not read or accessed
+  /// in its respective scope.
+  bool isKnownReadNone() const { return isKnown(NO_ACCESSES); }
+
+  /// Return true if we assume that the underlying value is not read or accessed
+  /// in its respective scope.
+  bool isAssumedReadNone() const { return isAssumed(NO_ACCESSES); }
+
+  /// Return true if we know that the underlying value is not accessed
+  /// (=written) in its respective scope.
+  bool isKnownReadOnly() const { return isKnown(NO_WRITES); }
+
+  /// Return true if we assume that the underlying value is not accessed
+  /// (=written) in its respective scope.
+  bool isAssumedReadOnly() const { return isAssumed(NO_WRITES); }
+
+  /// Return true if we know that the underlying value is not read in its
+  /// respective scope.
+  bool isKnownWriteOnly() const { return isKnown(NO_READS); }
+
+  /// Return true if we assume that the underlying value is not read in its
+  /// respective scope.
+  bool isAssumedWriteOnly() const { return isAssumed(NO_READS); }
+
+  /// Create an abstract attribute view for the position \p IRP.
+  static AAMemoryBehavior &createForPosition(const IRPosition &IRP,
+                                             Attributor &A);
+
+  /// Unique ID (due to the unique address)
+  static const char ID;
+};
+
 } // end namespace llvm
 
 #endif // LLVM_TRANSFORMS_IPO_FUNCTIONATTRS_H

llvm/lib/Transforms/IPO/Attributor.cpp

do {
 
     // Look through phi nodes, visit all live operands.
     if (auto *PHI = dyn_cast<PHINode>(V)) {
       assert(LivenessAA &&
              "Expected liveness in the presence of instructions!");
       for (unsigned u = 0, e = PHI->getNumIncomingValues(); u < e; u++) {
         const BasicBlock *IncomingBB = PHI->getIncomingBlock(u);
         if (LivenessAA->isAssumedDead(IncomingBB->getTerminator())) {
-          AnyDead =true;
+          AnyDead = true;
           continue;
         }
         Worklist.push_back(PHI->getIncomingValue(u));
       }
       continue;
     }
 
     // Once a leaf is reached we inform the user through the callback.
if (!ICS.hasOperandBundles()) {
         IRPositions.emplace_back(IRPosition::function(*Callee));
     }
     IRPositions.emplace_back(IRPosition::value(IRP.getAssociatedValue()));
     return;
   }
   }
 }
 
-bool IRPosition::hasAttr(ArrayRef<Attribute::AttrKind> AKs) const {
-  for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this))
+bool IRPosition::hasAttr(ArrayRef<Attribute::AttrKind> AKs,
+                         bool IgnoreSubsumingPositions) const {
+  for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this)) {
     for (Attribute::AttrKind AK : AKs)
       if (EquivIRP.getAttr(AK).getKindAsEnum() == AK)
         return true;
+    if (IgnoreSubsumingPositions)
+      break;
+  }
   return false;
 }
 
 void IRPosition::getAttrs(ArrayRef<Attribute::AttrKind> AKs,
                           SmallVectorImpl<Attribute> &Attrs) const {
   for (const IRPosition &EquivIRP : SubsumingPositionIterator(*this))
     for (Attribute::AttrKind AK : AKs) {
       const Attribute &Attr = EquivIRP.getAttr(AK);
struct AANoCaptureCallSiteReturned final : AANoCaptureImpl {
   AANoCaptureCallSiteReturned(const IRPosition &IRP) : AANoCaptureImpl(IRP) {}
 
   /// See AbstractAttribute::trackStatistics()
   void trackStatistics() const override {
     STATS_DECLTRACK_CSRET_ATTR(nocapture)
   }
 };
 
+/// -------------------- Memory Behavior Attributes ----------------------------
+/// Includes read-none, read-only, and write-only.
+/// ----------------------------------------------------------------------------
+struct AAMemoryBehaviorImpl : public AAMemoryBehavior {
+  AAMemoryBehaviorImpl(const IRPosition &IRP) : AAMemoryBehavior(IRP) {}
+
+  /// See AbstractAttribute::initialize(...).
+  void initialize(Attributor &A) override {
+    intersectAssumedBits(BEST_STATE);
+    getKnownStateFromValue(getIRPosition(), getState());
+    IRAttribute::initialize(A);
+  }
+
+  /// Return the memory behavior information encoded in the IR for \p IRP.
+  static void getKnownStateFromValue(const IRPosition &IRP,
+                                     IntegerState &State) {
+    SmallVector<Attribute, 2> Attrs;
+    IRP.getAttrs(AttrKinds, Attrs);
+    for (const Attribute &Attr : Attrs) {
+      switch (Attr.getKindAsEnum()) {
+      case Attribute::ReadNone:
+        State.addKnownBits(NO_ACCESSES);
+        break;
+      case Attribute::ReadOnly:
+        State.addKnownBits(NO_WRITES);
+        break;
+      case Attribute::WriteOnly:
+        State.addKnownBits(NO_READS);
+        break;
+      default:
+        llvm_unreachable("Unexpcted attribute!");
+      }
+    }
+
+    if (auto *I = dyn_cast<Instruction>(&IRP.getAnchorValue())) {
+      if (!I->mayReadFromMemory())
+        State.addKnownBits(NO_READS);
+      if (!I->mayWriteToMemory())
+        State.addKnownBits(NO_WRITES);
+    }
+  }
+
+  /// See AbstractAttribute::getDeducedAttributes(...).
+  void getDeducedAttributes(LLVMContext &Ctx,
+                            SmallVectorImpl<Attribute> &Attrs) const override {
+    assert(Attrs.size() == 0);
+    if (isAssumedReadNone())
+      Attrs.push_back(Attribute::get(Ctx, Attribute::ReadNone));
+    else if (isAssumedReadOnly())
+      Attrs.push_back(Attribute::get(Ctx, Attribute::ReadOnly));
+    else if (isAssumedWriteOnly())
+      Attrs.push_back(Attribute::get(Ctx, Attribute::WriteOnly));
+    assert(Attrs.size() <= 1);
+  }
+
+  /// See AbstractAttribute::manifest(...).
+  ChangeStatus manifest(Attributor &A) override {
+    IRPosition &IRP = getIRPosition();
+
+    // Check if we would improve the existing attributes first.
+    SmallVector<Attribute, 4> DeducedAttrs;
+    getDeducedAttributes(IRP.getAnchorValue().getContext(), DeducedAttrs);
+    if (llvm::all_of(DeducedAttrs, [&](const Attribute &Attr) {
+          return IRP.hasAttr(Attr.getKindAsEnum(),
+                             /* IgnoreSubsumingPositions */ true);
+        }))
+      return ChangeStatus::UNCHANGED;
+
+    // Clear existing attributes.
+    IRP.removeAttrs(AttrKinds);
+
+    // Use the generic manifest method.
+    return IRAttribute::manifest(A);
+  }
+
+  /// See AbstractState::getAsStr().
+  const std::string getAsStr() const override {
+    if (isAssumedReadNone())
+      return "readnone";
+    if (isAssumedReadOnly())
+      return "readonly";
+    if (isAssumedWriteOnly())
+      return "writeonly";
+    return "may-read/write";
+  }
+
+  /// The set of IR attributes AAMemoryBehavior deals with.
+  static const Attribute::AttrKind AttrKinds[3];
+};
+
+const Attribute::AttrKind AAMemoryBehaviorImpl::AttrKinds[] = {
+    Attribute::ReadNone, Attribute::ReadOnly, Attribute::WriteOnly};
+
+/// Memory behavior attribute for a floating value.
+struct AAMemoryBehaviorFloating : AAMemoryBehaviorImpl {
+  AAMemoryBehaviorFloating(const IRPosition &IRP) : AAMemoryBehaviorImpl(IRP) {}
+
+  /// See AbstractAttribute::initialize(...).
+  void initialize(Attributor &A) override {
+    AAMemoryBehaviorImpl::initialize(A);
+    // Initialize the use vector with all direct uses of the associated value.
+    for (const Use &U : getAssociatedValue().uses())
+      Uses.insert(&U);
+  }
+
+  /// See AbstractAttribute::updateImpl(...).
+  ChangeStatus updateImpl(Attributor &A) override;
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {
+    if (isAssumedReadNone())
+      STATS_DECLTRACK_FLOATING_ATTR(readnone)
+    else if (isAssumedReadOnly())
+      STATS_DECLTRACK_FLOATING_ATTR(readonly)
+    else if (isAssumedWriteOnly())
+      STATS_DECLTRACK_FLOATING_ATTR(writeonly)
+  }
+
+private:
+  /// Return true if users of \p UserI might access the underlying
+  /// variable/location described by \p U and should therefore be analyzed.
+  bool followUsersOfUseIn(Attributor &A, const Use *U,
+                          const Instruction *UserI);
+
+  /// Update the state according to the effect of use \p U in \p UserI.
+  void analyzeUseIn(Attributor &A, const Use *U, const Instruction *UserI);
+
+protected:
+  /// Container for (transitive) uses of the associated argument.
+  SetVector<const Use *> Uses;
+};
+
+/// Memory behavior attribute for function argument.
+struct AAMemoryBehaviorArgument : AAMemoryBehaviorFloating {
+  AAMemoryBehaviorArgument(const IRPosition &IRP)
+      : AAMemoryBehaviorFloating(IRP) {}
+
+  /// See AbstractAttribute::initialize(...).
+  void initialize(Attributor &A) override {
+    AAMemoryBehaviorFloating::initialize(A);
+
+    // TODO: From readattrs.ll: "inalloca parameters are always
+    //                           considered written"
+    if (hasAttr({Attribute::InAlloca}))
+      removeAssumedBits(NO_WRITES);
+
+    // Initialize the use vector with all direct uses of the associated value.
+    Argument *Arg = getAssociatedArgument();
+    if (!Arg || !Arg->getParent()->hasExactDefinition())
+      indicatePessimisticFixpoint();
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {
+    if (isAssumedReadNone())
+      STATS_DECLTRACK_ARG_ATTR(readnone)
+    else if (isAssumedReadOnly())
+      STATS_DECLTRACK_ARG_ATTR(readonly)
+    else if (isAssumedWriteOnly())
+      STATS_DECLTRACK_ARG_ATTR(writeonly)
+  }
+};
+
+struct AAMemoryBehaviorCallSiteArgument final : AAMemoryBehaviorArgument {
+  AAMemoryBehaviorCallSiteArgument(const IRPosition &IRP)
+      : AAMemoryBehaviorArgument(IRP) {}
+
+  /// See AbstractAttribute::updateImpl(...).
+  ChangeStatus updateImpl(Attributor &A) override {
+    // TODO: Once we have call site specific value information we can provide
+    //       call site specific liveness liveness information and then it makes
+    //       sense to specialize attributes for call sites arguments instead of
+    //       redirecting requests to the callee argument.
+    Argument *Arg = getAssociatedArgument();
+    const IRPosition &ArgPos = IRPosition::argument(*Arg);
+    auto &ArgAA = A.getAAFor<AAMemoryBehavior>(*this, ArgPos);
+    return clampStateAndIndicateChange(
+        getState(),
+        static_cast<const AANoCapture::StateType &>(ArgAA.getState()));
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {
+    if (isAssumedReadNone())
+      STATS_DECLTRACK_CSARG_ATTR(readnone)
+    else if (isAssumedReadOnly())
+      STATS_DECLTRACK_CSARG_ATTR(readonly)
+    else if (isAssumedWriteOnly())
+      STATS_DECLTRACK_CSARG_ATTR(writeonly)
+  }
+};
+
+/// Memory behavior attribute for a call site return position.
+struct AAMemoryBehaviorCallSiteReturned final : AAMemoryBehaviorFloating {
+  AAMemoryBehaviorCallSiteReturned(const IRPosition &IRP)
+      : AAMemoryBehaviorFloating(IRP) {}
+
+  /// See AbstractAttribute::manifest(...).
+  ChangeStatus manifest(Attributor &A) override {
+    // We do not annotate returned values.
+    return ChangeStatus::UNCHANGED;
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {}
+};
+
+/// An AA to represent the memory behavior function attributes.
+struct AAMemoryBehaviorFunction final : public AAMemoryBehaviorImpl {
+  AAMemoryBehaviorFunction(const IRPosition &IRP) : AAMemoryBehaviorImpl(IRP) {}
+
+  /// See AbstractAttribute::updateImpl(Attributor &A).
+  virtual ChangeStatus updateImpl(Attributor &A) override;
+
+  /// See AbstractAttribute::manifest(...).
+  ChangeStatus manifest(Attributor &A) override {
+    Function &F = cast<Function>(getAnchorValue());
+    if (isAssumedReadNone()) {
+      F.removeFnAttr(Attribute::ArgMemOnly);
+      F.removeFnAttr(Attribute::InaccessibleMemOnly);
+      F.removeFnAttr(Attribute::InaccessibleMemOrArgMemOnly);
+    }
+    return AAMemoryBehaviorImpl::manifest(A);
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {
+    if (isAssumedReadNone())
+      STATS_DECLTRACK_FN_ATTR(readnone)
+    else if (isAssumedReadOnly())
+      STATS_DECLTRACK_FN_ATTR(readonly)
+    else if (isAssumedWriteOnly())
+      STATS_DECLTRACK_FN_ATTR(writeonly)
+  }
+};
+
+/// AAMemoryBehavior attribute for call sites.
+struct AAMemoryBehaviorCallSite final : AAMemoryBehaviorImpl {
+  AAMemoryBehaviorCallSite(const IRPosition &IRP) : AAMemoryBehaviorImpl(IRP) {}
+
+  /// See AbstractAttribute::initialize(...).
+  void initialize(Attributor &A) override {
+    AAMemoryBehaviorImpl::initialize(A);
+    Function *F = getAssociatedFunction();
+    if (!F || !F->hasExactDefinition())
+      indicatePessimisticFixpoint();
+  }
+
+  /// See AbstractAttribute::updateImpl(...).
+  ChangeStatus updateImpl(Attributor &A) override {
+    // TODO: Once we have call site specific value information we can provide
+    //       call site specific liveness liveness information and then it makes
+    //       sense to specialize attributes for call sites arguments instead of
+    //       redirecting requests to the callee argument.
+    Function *F = getAssociatedFunction();
+    const IRPosition &FnPos = IRPosition::function(*F);
+    auto &FnAA = A.getAAFor<AAMemoryBehavior>(*this, FnPos);
+    return clampStateAndIndicateChange(
+        getState(), static_cast<const AAAlign::StateType &>(FnAA.getState()));
+  }
+
+  /// See AbstractAttribute::trackStatistics()
+  void trackStatistics() const override {
+    if (isAssumedReadNone())
+      STATS_DECLTRACK_CS_ATTR(readnone)
+    else if (isAssumedReadOnly())
+      STATS_DECLTRACK_CS_ATTR(readonly)
+    else if (isAssumedWriteOnly())
+      STATS_DECLTRACK_CS_ATTR(writeonly)
+  }
+};
+
+ChangeStatus AAMemoryBehaviorFunction::updateImpl(Attributor &A) {
+
+  // The current assumed state used to determine a change.
+  auto AssumedState = getAssumed();
+
+  auto CheckRWInst = [&](Instruction &I) {
+    // If the instruction has an own memory behavior state, use it to restrict
+    // the local state. No further analysis is required as the other memory
+    // state is as optimistic as it gets.
+    if (ImmutableCallSite ICS = ImmutableCallSite(&I)) {
+      const auto &MemBehaviorAA = A.getAAFor<AAMemoryBehavior>(
+          *this, IRPosition::callsite_function(ICS));
+      intersectAssumedBits(MemBehaviorAA.getAssumed());
+      return !isAtFixpoint();
+    }
+
+    // Remove access kind modifiers if necessary.
+    if (I.mayReadFromMemory())
+      removeAssumedBits(NO_READS);
+    if (I.mayWriteToMemory())
+      removeAssumedBits(NO_WRITES);
+    return !isAtFixpoint();
+  };
+
+  if (!A.checkForAllReadWriteInstructions(CheckRWInst, *this))
+    return indicatePessimisticFixpoint();
+
+  return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED
+                                        : ChangeStatus::UNCHANGED;
+}
+
+ChangeStatus AAMemoryBehaviorFloating::updateImpl(Attributor &A) {
+
+  const IRPosition &IRP = getIRPosition();
+  const IRPosition &FnPos = IRPosition::function_scope(IRP);
+  AAMemoryBehavior::StateType &S = getState();
+
+  // First, check the function scope. We take the known information and we avoid
+  // work if the assumed information implies the current assumed information for
+  // this attribute.
+  const auto &FnMemAA = A.getAAFor<AAMemoryBehavior>(*this, FnPos);
+  S.addKnownBits(FnMemAA.getKnown());
+  if ((S.getAssumed() & FnMemAA.getAssumed()) == S.getAssumed()) {
+    return ChangeStatus::UNCHANGED;
+  }
+
+  // Make sure the value is not captured (except through "return"), if
+  // it is, any information derived would be irrelevant anyway as we cannot
+  // check the potential aliases introduced by the capture.
+  const auto &ArgNoCaptureAA = A.getAAFor<AANoCapture>(*this, IRP);
+  if (!ArgNoCaptureAA.isAssumedNoCaptureMaybeReturned())
+    return indicatePessimisticFixpoint();
+
+  // The current assumed state used to determine a change.
+  auto AssumedState = S.getAssumed();
+
+  // Liveness information to exclude dead users.
+  // TODO: Take the FnPos once we have call site specific liveness information.
+  const auto &LivenessAA = A.getAAFor<AAIsDead>(
+      *this, IRPosition::function(*IRP.getAssociatedFunction()));
+
+  // Visit and expand uses until all are analyzed or a fixpoint is reached.
+  for (unsigned i = 0; i < Uses.size() && !isAtFixpoint(); i++) {
+    const Use *U = Uses[i];
+    Instruction *UserI = cast<Instruction>(U->getUser());
+    LLVM_DEBUG(dbgs() << "[AAMemoryBehavior] Use: " << **U << " in " << *UserI
+                      << " [Dead: " << (LivenessAA.isAssumedDead(UserI))
+                      << "]\n");
+    if (LivenessAA.isAssumedDead(UserI))
+      continue;
+
+    // Check if the users of UserI should also be visited.
+    if (followUsersOfUseIn(A, U, UserI))
+      for (const Use &UserIUse : UserI->uses())
+        Uses.insert(&UserIUse);
+
+    // If UserI might touch memory we analyze the use in detail.
+    if (UserI->mayReadOrWriteMemory())
+      analyzeUseIn(A, U, UserI);
+  }
+
+  return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED
+                                        : ChangeStatus::UNCHANGED;
+}
+
+bool AAMemoryBehaviorFloating::followUsersOfUseIn(Attributor &A, const Use *U,
+                                                  const Instruction *UserI) {
+  // The loaded value is unrelated to the pointer argument, no need to
+  // follow the users of the load.
+  if (isa<LoadInst>(UserI))
+    return false;
+
+  // By default we follow all uses assuming UserI might leak information on U,
+  // we have special handling for call sites operands though.
+  ImmutableCallSite ICS(UserI);
+  if (!ICS || !ICS.isArgOperand(U))
+    return true;
+
+  // If the use is a call argument known not to be captured, the users of
+  // the call do not need to be visited because they have to be unrelated to
+  // the input. Note that this check is not trivial even though we disallow
+  // general capturing of the underlying argument. The reason is that the
+  // call might the argument "through return", which we allow and for which we
+  // need to check call users.
+  unsigned ArgNo = ICS.getArgumentNo(U);
+  const auto &ArgNoCaptureAA =
+      A.getAAFor<AANoCapture>(*this, IRPosition::callsite_argument(ICS, ArgNo));
+  return !ArgNoCaptureAA.isAssumedNoCapture();
+}
+
+void AAMemoryBehaviorFloating::analyzeUseIn(Attributor &A, const Use *U,
+                                            const Instruction *UserI) {
+  assert(UserI->mayReadOrWriteMemory());
+
+  switch (UserI->getOpcode()) {
+  case Instruction::Load:
+    // Loads cause the NO_READS property to disappear.
+    removeAssumedBits(NO_READS);
+    return;
+
+  case Instruction::Store:
+    // Stores cause the NO_WRITES property to disappear if the use is the
+    // pointer operand. Note that we do assume that capturing was taken care of
+    // somewhere else.
+    if (cast<StoreInst>(UserI)->getPointerOperand() == U->get())
+      removeAssumedBits(NO_WRITES);
+    return;
+
+  case Instruction::Call:
+  case Instruction::CallBr:
+  case Instruction::Invoke: {
+    // For call sites we look at the argument memory behavior attribute (this
+    // could be recursive!) in order to restrict our own state.
+    ImmutableCallSite ICS(UserI);
+
+    // Give up on operand bundles.
+    if (ICS.isBundleOperand(U)) {
+      indicatePessimisticFixpoint();
+      return;
+    }
+
+    // Calling a function does read the function pointer, maybe write it if the
+    // function is self-modifying.
+    if (ICS.isCallee(U)) {
+      removeAssumedBits(NO_READS);
+      break;
+    }
+
+    // Adjust the possible access behavior based on the information on the
+    // argument.
+    unsigned ArgNo = ICS.getArgumentNo(U);
+    const IRPosition &ArgPos = IRPosition::callsite_argument(ICS, ArgNo);
+    const auto &MemBehaviorAA = A.getAAFor<AAMemoryBehavior>(*this, ArgPos);
+    // "assumed" has at most the same bits as the MemBehaviorAA assumed
+    // and at least "known".
+    intersectAssumedBits(MemBehaviorAA.getAssumed());
+    return;
+  }
+  };
+
+  // Generally, look at the "may-properties" and adjust the assumed state if we
+  // did not trigger special handling before.
+  if (UserI->mayReadFromMemory())
+    removeAssumedBits(NO_READS);
+  if (UserI->mayWriteToMemory())
+    removeAssumedBits(NO_WRITES);
+}
+
 /// ----------------------------------------------------------------------------
 ///                               Attributor
 /// ----------------------------------------------------------------------------
 
 bool Attributor::isAssumedDead(const AbstractAttribute &AA,
                                const AAIsDead *LivenessAA) {
   const Instruction *CtxI = AA.getIRPosition().getCtxI();
   if (!CtxI)
bool Attributor::checkForAllInstructions(
   // TODO: use the function scope once we have call site AAReturnedValues.
   const IRPosition &QueryIRP = IRPosition::function(*AssociatedFunction);
   const auto &LivenessAA =
       getAAFor<AAIsDead>(QueryingAA, QueryIRP, /* TrackDependence */ false);
   bool AnyDead = false;
 
   auto &OpcodeInstMap =
       InfoCache.getOpcodeInstMapForFunction(*AssociatedFunction);
-  if (!checkForAllInstructionsImpl(OpcodeInstMap, Pred, &LivenessAA, AnyDead, Opcodes))
+  if (!checkForAllInstructionsImpl(OpcodeInstMap, Pred, &LivenessAA, AnyDead,
+                                   Opcodes))
     return false;
 
   // If we actually used liveness information so we have to record a dependence.
   if (AnyDead)
     recordDependence(LivenessAA, QueryingAA);
 
   return true;
 }
void Attributor::identifyDefaultAbstractAttributes(Function &F) {
   getOrCreateAAFor<AANoSync>(FPos);
 
   // Every function might be "no-free".
   getOrCreateAAFor<AANoFree>(FPos);
 
   // Every function might be "no-return".
   getOrCreateAAFor<AANoReturn>(FPos);
 
+  // Every function might be "readnone/readonly/writeonly/...".
+  getOrCreateAAFor<AAMemoryBehavior>(FPos);
+
   // Return attributes are only appropriate if the return type is non void.
   Type *ReturnType = F.getReturnType();
   if (!ReturnType->isVoidTy()) {
     // Argument attribute "returned" --- Create only one per function even
     // though it is an argument attribute.
     getOrCreateAAFor<AAReturnedValues>(FPos);
 
     if (ReturnType->isPointerTy()) {
if (Arg.getType()->isPointerTy()) {
       // Every argument with pointer type might be marked dereferenceable.
       getOrCreateAAFor<AADereferenceable>(ArgPos);
 
       // Every argument with pointer type might be marked align.
       getOrCreateAAFor<AAAlign>(ArgPos);
 
       // Every argument with pointer type might be marked nocapture.
       getOrCreateAAFor<AANoCapture>(ArgPos);
+
+      // Every argument with pointer type might be marked
+      // "readnone/readonly/writeonly/..."
+      getOrCreateAAFor<AAMemoryBehavior>(ArgPos);
     }
   }
 
   auto CallSitePred = [&](Instruction &I) -> bool {
     CallSite CS(&I);
     if (CS.getCalledFunction()) {
       for (int i = 0, e = CS.getCalledFunction()->arg_size(); i < e; i++) {
         if (!CS.getArgument(i)->getType()->isPointerTy())

 const char AANoRecurse::ID = 0;
 const char AAWillReturn::ID = 0;
 const char AANoAlias::ID = 0;
 const char AANoReturn::ID = 0;
 const char AAIsDead::ID = 0;
 const char AADereferenceable::ID = 0;
 const char AAAlign::ID = 0;
 const char AANoCapture::ID = 0;
+const char AAMemoryBehavior::ID = 0;
 
 // Macro magic to create the static generator function for attributes that
 // follow the naming scheme.
 
 #define SWITCH_PK_INV(CLASS, PK, POS_NAME)                                     \
   case IRPosition::PK:                                                         \
     llvm_unreachable("Cannot create " #CLASS " for a " POS_NAME " position!");
 
switch (IRP.getPositionKind()) {                                           \
       SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument)                     \
       SWITCH_PK_CREATE(CLASS, IRP, IRP_RETURNED, Returned)                     \
       SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned)   \
       SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument)   \
     }                                                                          \
     return *AA;                                                                \
   }
 
+#define CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION(CLASS)                  \
+  CLASS &CLASS::createForPosition(const IRPosition &IRP, Attributor &A) {      \
+    CLASS *AA = nullptr;                                                       \
+    switch (IRP.getPositionKind()) {                                           \
+      SWITCH_PK_INV(CLASS, IRP_INVALID, "invalid")                             \
+      SWITCH_PK_INV(CLASS, IRP_RETURNED, "returned")                           \
+      SWITCH_PK_CREATE(CLASS, IRP, IRP_FUNCTION, Function)                     \
+      SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE, CallSite)                    \
+      SWITCH_PK_CREATE(CLASS, IRP, IRP_FLOAT, Floating)                        \
+      SWITCH_PK_CREATE(CLASS, IRP, IRP_ARGUMENT, Argument)                     \
+      SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_RETURNED, CallSiteReturned)   \
+      SWITCH_PK_CREATE(CLASS, IRP, IRP_CALL_SITE_ARGUMENT, CallSiteArgument)   \
+    }                                                                          \
+    AA->initialize(A);                                                         \
+    return *AA;                                                                \
+  }
+
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoUnwind)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoSync)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoFree)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoRecurse)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAWillReturn)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoReturn)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAIsDead)
 CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAReturnedValues)
 
 CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANonNull)
 CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoAlias)
 CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AADereferenceable)
 CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAAlign)
 CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION(AANoCapture)
 
+CREATE_NON_RET_ABSTRACT_ATTRIBUTE_FOR_POSITION(AAMemoryBehavior)
+
 #undef CREATE_FUNCTION_ABSTRACT_ATTRIBUTE_FOR_POSITION
 #undef CREATE_VALUE_ABSTRACT_ATTRIBUTE_FOR_POSITION
 #undef SWITCH_PK_CREATE
 #undef SWITCH_PK_INV
 
 INITIALIZE_PASS_BEGIN(AttributorLegacyPass, "attributor",
                       "Deduce and propagate attributes", false, false)
 INITIALIZE_PASS_END(AttributorLegacyPass, "attributor",
                     "Deduce and propagate attributes", false, false)

llvm/test/Transforms/FunctionAttrs/align.ll

 ; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=6 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 ; Test cases specifically designed for "align" attribute.
 ; We use FIXME's to indicate problems and missing attributes.
 
 
 ; TEST 1
-; ATTRIBUTOR: define align 8 i32* @test1(i32* returned align 8 "no-capture-maybe-returned" %0)
+; ATTRIBUTOR: define align 8 i32* @test1(i32* readnone returned align 8 "no-capture-maybe-returned" %0)
 define i32* @test1(i32* align 8 %0) #0 {
   ret i32* %0
 }
 
 ; TEST 2
-; ATTRIBUTOR: define i32* @test2(i32* returned "no-capture-maybe-returned" %0)
+; ATTRIBUTOR: define i32* @test2(i32* readnone returned "no-capture-maybe-returned" %0)
 define i32* @test2(i32* %0) #0 {
   ret i32* %0
 }
 
 ; TEST 3
-; ATTRIBUTOR: define align 4 i32* @test3(i32* align 8 "no-capture-maybe-returned" %0, i32* align 4 "no-capture-maybe-returned" %1, i1 %2)
+; ATTRIBUTOR: define align 4 i32* @test3(i32* readnone align 8 "no-capture-maybe-returned" %0, i32* readnone align 4 "no-capture-maybe-returned" %1, i1 %2)
 define i32* @test3(i32* align 8 %0, i32* align 4 %1, i1 %2) #0 {
   %ret = select i1 %2, i32* %0, i32* %1
   ret i32* %ret
 }
 
 ; TEST 4
-; ATTRIBUTOR: define align 32 i32* @test4(i32* align 32 "no-capture-maybe-returned" %0, i32* align 32 "no-capture-maybe-returned" %1, i1 %2)
+; ATTRIBUTOR: define align 32 i32* @test4(i32* readnone align 32 "no-capture-maybe-returned" %0, i32* readnone align 32 "no-capture-maybe-returned" %1, i1 %2)
 define i32* @test4(i32* align 32 %0, i32* align 32 %1, i1 %2) #0 {
   %ret = select i1 %2, i32* %0, i32* %1
   ret i32* %ret
 }
 
 ; TEST 5
 declare i32* @unknown()
 declare align 8 i32* @align8()

 
 ; <label>:5:                                      ; preds = %1, %3
   %6 = phi i8* [ %4, %3 ], [ @a1, %1 ]
   ret i8* %6
 }
 
 ; TEST 7
 ; Better than IR information
-; ATTRIBUTOR: define align 32 i32* @test7(i32* returned align 32 "no-capture-maybe-returned" %p)
+; ATTRIBUTOR: define align 32 i32* @test7(i32* readnone returned align 32 "no-capture-maybe-returned" %p)
 define align 4 i32* @test7(i32* align 32 %p) #0 {
   tail call i8* @f1(i8* align 8 dereferenceable(1) @a1)
   ret i32* %p
 }
 
 
 ; TEST 8
 define void @test8_helper() {
   %ptr0 = tail call i32* @unknown()
   %ptr1 = tail call align 4 i32* @unknown()
   %ptr2 = tail call align 8 i32* @unknown()
 
   tail call void @test8(i32* %ptr1, i32* %ptr1, i32* %ptr0)
 ; ATTRIBUTOR: tail call void @test8(i32* align 4 %ptr1, i32* align 4 %ptr1, i32* %ptr0)
   tail call void @test8(i32* %ptr2, i32* %ptr1, i32* %ptr1)
 ; ATTRIBUTOR: tail call void @test8(i32* align 8 %ptr2, i32* align 4 %ptr1, i32* align 4 %ptr1)
   tail call void @test8(i32* %ptr2, i32* %ptr1, i32* %ptr1)
 ; ATTRIBUTOR: tail call void @test8(i32* align 8 %ptr2, i32* align 4 %ptr1, i32* align 4 %ptr1)
   ret void
 }
 
 define internal void @test8(i32* %a, i32* %b, i32* %c) {
-; ATTRIBUTOR: define internal void @test8(i32* nocapture align 4 %a, i32* nocapture align 4 %b, i32* nocapture %c)
+; ATTRIBUTOR: define internal void @test8(i32* nocapture readnone align 4 %a, i32* nocapture readnone align 4 %b, i32* nocapture readnone %c)
   ret void
 }
 
 declare void @test9_helper(i32* %A)
 define void @test9_traversal(i1 %c, i32* align 4 %B, i32* align 8 %C) {
   %sel = select i1 %c, i32* %B, i32* %C
   call void @test9_helper(i32* %sel)
   ret void

llvm/test/Transforms/FunctionAttrs/arg_nocapture.ll

 }
 
 ; TEST SCC with various calls, casts, and comparisons agains NULL
 ;
 ; CHECK: define dereferenceable_or_null(4) float* @scc_A(i32* readnone returned dereferenceable_or_null(4) "no-capture-maybe-returned" %a)
 ;
 ; CHECK: define dereferenceable_or_null(8) i64* @scc_B(double* readnone returned dereferenceable_or_null(8) "no-capture-maybe-returned" %a)
 ;
-; FIXME: readnone missing for %s
-; CHECK: define dereferenceable_or_null(2) i8* @scc_C(i16* returned dereferenceable_or_null(2) "no-capture-maybe-returned" %a)
+; CHECK: define dereferenceable_or_null(2) i8* @scc_C(i16* readnone returned dereferenceable_or_null(2) "no-capture-maybe-returned" %a)
 ;
 ; float *scc_A(int *a) {
 ;   return (float*)(a ? (int*)scc_A((int*)scc_B((double*)scc_C((short*)a))) : a);
 ; }
 ;
 ; long *scc_B(double *a) {
 ;   return (long*)(a ? scc_C((short*)scc_B((double*)scc_A((int*)a))) : a);
 ; }

 ; TEST "captured" only through return
 ;
 ; long *not_captured_but_returned_0(long *a) {
 ;   *a1 = 0;
 ;   return a;
 ; }
 ;
 ; There should *not* be a no-capture attribute on %a
-; CHECK: define i64* @not_captured_but_returned_0(i64* returned "no-capture-maybe-returned" %a)
+; CHECK: define i64* @not_captured_but_returned_0(i64* returned writeonly "no-capture-maybe-returned" %a)
 define i64* @not_captured_but_returned_0(i64* %a) #0 {
 entry:
   store i64 0, i64* %a, align 8
   ret i64* %a
 }
 
 ; TEST "captured" only through return
 ;
 ; long *not_captured_but_returned_1(long *a) {
 ;   *(a+1) = 1;
 ;   return a + 1;
 ; }
 ;
 ; There should *not* be a no-capture attribute on %a
-; CHECK: define nonnull i64* @not_captured_but_returned_1(i64* "no-capture-maybe-returned" %a)
+; CHECK: define nonnull i64* @not_captured_but_returned_1(i64* writeonly "no-capture-maybe-returned" %a)
 define i64* @not_captured_but_returned_1(i64* %a) #0 {
 entry:
   %add.ptr = getelementptr inbounds i64, i64* %a, i64 1
   store i64 1, i64* %add.ptr, align 8
   ret i64* %add.ptr
 }
 
 ; TEST calls to "captured" only through return functions
 ;
 ; void test_not_captured_but_returned_calls(long *a) {
 ;   not_captured_but_returned_0(a);
 ;   not_captured_but_returned_1(a);
 ; }
 ;
-; FIXME: no-capture missing for %a
-; CHECK: define void @test_not_captured_but_returned_calls(i64* nocapture %a)
+; CHECK: define void @test_not_captured_but_returned_calls(i64* nocapture writeonly %a)
 define void @test_not_captured_but_returned_calls(i64* %a) #0 {
 entry:
   %call = call i64* @not_captured_but_returned_0(i64* %a)
   %call1 = call i64* @not_captured_but_returned_1(i64* %a)
   ret void
 }
 
 ; TEST "captured" only through transitive return
 ;
 ; long* negative_test_not_captured_but_returned_call_0a(long *a) {
 ;   return not_captured_but_returned_0(a);
 ; }
 ;
 ; There should *not* be a no-capture attribute on %a
-; CHECK: define i64* @negative_test_not_captured_but_returned_call_0a(i64* returned "no-capture-maybe-returned" %a)
+; CHECK: define i64* @negative_test_not_captured_but_returned_call_0a(i64* returned writeonly "no-capture-maybe-returned" %a)
 define i64* @negative_test_not_captured_but_returned_call_0a(i64* %a) #0 {
 entry:
   %call = call i64* @not_captured_but_returned_0(i64* %a)
   ret i64* %call
 }
 
 ; TEST captured through write
 ;
 ; void negative_test_not_captured_but_returned_call_0b(long *a) {
 ;   *a = (long)not_captured_but_returned_0(a);
 ; }
 ;
 ; There should *not* be a no-capture attribute on %a
-; CHECK: define void @negative_test_not_captured_but_returned_call_0b(i64* %a)
+; CHECK: define void @negative_test_not_captured_but_returned_call_0b(i64* writeonly %a)
 define void @negative_test_not_captured_but_returned_call_0b(i64* %a) #0 {
 entry:
   %call = call i64* @not_captured_but_returned_0(i64* %a)
   %0 = ptrtoint i64* %call to i64
   store i64 %0, i64* %a, align 8
   ret void
 }
 
 ; TEST "captured" only through transitive return
 ;
 ; long* negative_test_not_captured_but_returned_call_1a(long *a) {
 ;   return not_captured_but_returned_1(a);
 ; }
 ;
 ; There should *not* be a no-capture attribute on %a
-; CHECK: define nonnull i64* @negative_test_not_captured_but_returned_call_1a(i64* "no-capture-maybe-returned" %a)
+; CHECK: define nonnull i64* @negative_test_not_captured_but_returned_call_1a(i64* writeonly "no-capture-maybe-returned" %a)
 define i64* @negative_test_not_captured_but_returned_call_1a(i64* %a) #0 {
 entry:
   %call = call i64* @not_captured_but_returned_1(i64* %a)
   ret i64* %call
 }
 
 ; TEST captured through write
 ;
 ; void negative_test_not_captured_but_returned_call_1b(long *a) {
 ;   *a = (long)not_captured_but_returned_1(a);
 ; }
 ;
 ; There should *not* be a no-capture attribute on %a
-; CHECK: define void @negative_test_not_captured_but_returned_call_1b(i64* %a)
+; CHECK: define void @negative_test_not_captured_but_returned_call_1b(i64* writeonly %a)
 define void @negative_test_not_captured_but_returned_call_1b(i64* %a) #0 {
 entry:
   %call = call i64* @not_captured_but_returned_1(i64* %a)
   %0 = ptrtoint i64* %call to i64
   store i64 %0, i64* %call, align 8
   ret void
 }
 

 r:
   %phi = phi i32* [ %b, %ret_arg ], [ %call, %ret_unknown ]
   ret i32* %phi
 }
 
 
 ; TEST not captured by readonly external function
 ;
-; CHECK: define void @not_captured_by_readonly_call(i32* nocapture %b)
+; CHECK: define void @not_captured_by_readonly_call(i32* nocapture readonly %b)
 declare i32* @readonly_unknown(i32*, i32*) readonly
 
 define void @not_captured_by_readonly_call(i32* %b) #0 {
 entry:
   %call = call i32* @readonly_unknown(i32* %b, i32* %b)
   ret void
 }
 

llvm/test/Transforms/FunctionAttrs/arg_returned.ll

 return:                                           ; preds = %cond.end, %if.then3, %if.then
   %retval.0 = phi i32 [ %call1, %if.then ], [ %call11, %if.then3 ], [ %cond, %cond.end ]
   ret i32 %retval.0
 }
 
 
 ; TEST SCC test returning a pointer value argument
 ;
-; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
-; BOTH-NEXT: define double* @ptr_sink_r0(double* readnone returned "no-capture-maybe-returned" %r)
-; BOTH: Function Attrs: nofree noinline nosync nounwind readnone uwtable
-; BOTH-NEXT: define double* @ptr_scc_r1(double* %a, double* readnone returned %r, double* nocapture readnone %b)
-; BOTH: Function Attrs: nofree noinline nosync nounwind readnone uwtable
-; BOTH-NEXT: define double* @ptr_scc_r2(double* readnone %a, double* readnone %b, double* readnone returned %r)
-;
 ; FNATTR: define double* @ptr_sink_r0(double* readnone returned %r)
 ; FNATTR: define double* @ptr_scc_r1(double* %a, double* readnone %r, double* nocapture readnone %b)
 ; FNATTR: define double* @ptr_scc_r2(double* readnone %a, double* readnone %b, double* readnone %r)
 ;
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @ptr_sink_r0(double* returned "no-capture-maybe-returned" %r)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @ptr_scc_r1(double* %a, double* returned %r, double* nocapture %b)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @ptr_scc_r2(double* %a, double* %b, double* returned %r)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @ptr_sink_r0(double* readnone returned "no-capture-maybe-returned" %r)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @ptr_scc_r1(double* readnone %a, double* readnone returned %r, double* nocapture readnone %b)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @ptr_scc_r2(double* readnone %a, double* readnone %b, double* readnone returned %r)
 ;
 ; double* ptr_scc_r1(double* a, double* b, double* r);
 ; double* ptr_scc_r2(double* a, double* b, double* r);
 ;
 ; __attribute__((noinline)) double* ptr_sink_r0(double* r) {
 ;   return r;
 ; }
 ;
entry:
   %sel = select i1 %tobool, i32* undef, i32* %call
   ret i32* %sel
 }
 
 ; TEST another SCC test
 ;
 ; FNATTR:  define i32* @rt2_helper(i32* %a)
 ; FNATTR:  define i32* @rt2(i32* readnone %a, i32* readnone %b)
-; BOTH:    define i32* @rt2_helper(i32* returned %a)
+; BOTH:    define i32* @rt2_helper(i32* readnone returned %a)
 ; BOTH:    define i32* @rt2(i32* readnone %a, i32* readnone "no-capture-maybe-returned" %b)
 define i32* @rt2_helper(i32* %a) #0 {
 entry:
   %call = call i32* @rt2(i32* %a, i32* %a)
   ret i32* %call
 }
 
 define i32* @rt2(i32* %a, i32 *%b) #0 {
if.end:
   %sel = phi i32* [ %b, %entry], [%call, %if.then]
   ret i32* %sel
 }
 
 ; TEST another SCC test
 ;
 ; FNATTR:  define i32* @rt3_helper(i32* %a, i32* %b)
 ; FNATTR:  define i32* @rt3(i32* readnone %a, i32* readnone %b)
-; BOTH:    define i32* @rt3_helper(i32* %a, i32* returned "no-capture-maybe-returned" %b)
+; BOTH:    define i32* @rt3_helper(i32* readnone %a, i32* readnone returned "no-capture-maybe-returned" %b)
 ; BOTH:    define i32* @rt3(i32* readnone %a, i32* readnone returned "no-capture-maybe-returned" %b)
 define i32* @rt3_helper(i32* %a, i32* %b) #0 {
 entry:
   %call = call i32* @rt3(i32* %a, i32* %b)
   ret i32* %call
 }
 
 define i32* @rt3(i32* %a, i32 *%b) #0 {

 ;    return r;
 ;  }
 ;
 ; BOTH: declare void @unknown_fn(i32* (i32*)*)
 ;
 ; BOTH:       Function Attrs: noinline nounwind uwtable
 ; BOTH-NEXT:  define i32* @calls_unknown_fn(i32* readnone returned "no-capture-maybe-returned" %r)
 ; FNATTR:     define i32* @calls_unknown_fn(i32* readnone returned %r)
-; ATTRIBUTOR: define i32* @calls_unknown_fn(i32* returned "no-capture-maybe-returned" %r)
+; ATTRIBUTOR: define i32* @calls_unknown_fn(i32* readnone returned "no-capture-maybe-returned" %r)
 declare void @unknown_fn(i32* (i32*)*) #0
 
 define i32* @calls_unknown_fn(i32* %r) #0 {
   tail call void @unknown_fn(i32* (i32*)* nonnull @calls_unknown_fn)
   ret i32* %r
 }
 
 

 ;     x = b;
 ;   return b == 0? b : x;
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
 ; BOTH-NEXT: define double @select_and_phi(double returned %b)
 ;
 ; FNATTR:     define double @select_and_phi(double %b)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define double @select_and_phi(double returned %b)
 define double @select_and_phi(double %b) #0 {
 entry:
   %cmp = fcmp ogt double %b, 0.000000e+00
   br i1 %cmp, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry
   br label %if.end

 ;   return b == 0? b : x;
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; BOTH-NEXT: define double @recursion_select_and_phi(i32 %a, double returned %b)
 ;
 ; FNATTR:     define double @recursion_select_and_phi(i32 %a, double %b)
 ;
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define double @recursion_select_and_phi(i32 %a, double returned %b)
 define double @recursion_select_and_phi(i32 %a, double %b) #0 {
 entry:
   %dec = add nsw i32 %a, -1
   %cmp = icmp sgt i32 %a, 0
   br i1 %cmp, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry

 ;   return (double*)b;
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
 ; BOTH-NEXT:  define double* @bitcast(i32* readnone returned "no-capture-maybe-returned" %b)
 ;
 ; FNATTR:     define double* @bitcast(i32* readnone %b)
 ;
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @bitcast(i32* returned "no-capture-maybe-returned" %b)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @bitcast(i32* readnone returned "no-capture-maybe-returned" %b)
 define double* @bitcast(i32* %b) #0 {
 entry:
   %bc0 = bitcast i32* %b to double*
   ret double* %bc0
 }
 
 
 ; TEST returned argument goes through select and phi interleaved with bitcasts
 ;
 ; double* bitcasts_select_and_phi(int* b) {
 ;   double* x = b;
 ;   if (b == 0)
 ;     x = b;
 ;   return b != 0 ? b : x;
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
 ; BOTH-NEXT: define double* @bitcasts_select_and_phi(i32* readnone returned %b)
 ;
 ; FNATTR:     define double* @bitcasts_select_and_phi(i32* readnone %b)
 ;
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @bitcasts_select_and_phi(i32* returned %b)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @bitcasts_select_and_phi(i32* readnone returned %b)
 define double* @bitcasts_select_and_phi(i32* %b) #0 {
 entry:
   %bc0 = bitcast i32* %b to double*
   %cmp = icmp eq double* %bc0, null
   br i1 %cmp, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry
   %bc1 = bitcast i32* %b to double*

 ;   /* return undef */
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
 ; BOTH-NEXT:  define double* @ret_arg_arg_undef(i32* readnone returned %b)
 ;
 ; FNATTR:     define double* @ret_arg_arg_undef(i32* readnone %b)
 ;
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @ret_arg_arg_undef(i32* returned %b)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @ret_arg_arg_undef(i32* readnone returned %b)
 define double* @ret_arg_arg_undef(i32* %b) #0 {
 entry:
   %bc0 = bitcast i32* %b to double*
   %cmp = icmp eq double* %bc0, null
   br i1 %cmp, label %ret_arg0, label %if.end
 
 ret_arg0:
   %bc1 = bitcast i32* %b to double*

 ;   /* return undef */
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
 ; BOTH-NEXT:  define double* @ret_undef_arg_arg(i32* readnone returned %b)
 ;
 ; FNATTR:     define double* @ret_undef_arg_arg(i32* readnone %b)
 ;
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define double* @ret_undef_arg_arg(i32* returned %b)
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define double* @ret_undef_arg_arg(i32* readnone returned %b)
 define double* @ret_undef_arg_arg(i32* %b) #0 {
 entry:
   %bc0 = bitcast i32* %b to double*
   %cmp = icmp eq double* %bc0, null
   br i1 %cmp, label %ret_undef, label %if.end
 
 ret_undef:
   ret double *undef

 ;     return (double*)b;
 ;   /* return undef */
 ; }
 ;
 ; BOTH: Function Attrs: nofree noinline norecurse nosync nounwind readnone uwtable
 ; BOTH-NEXT:  define double* @ret_undef_arg_undef(i32* readnone returned %b)
 ;
 ; FNATTR:     define double* @ret_undef_arg_undef(i32* readnone %b)
-; ATTRIBUTOR: define double* @ret_undef_arg_undef(i32* returned %b)
+; ATTRIBUTOR: define double* @ret_undef_arg_undef(i32* readnone returned %b)
 define double* @ret_undef_arg_undef(i32* %b) #0 {
 entry:
   %bc0 = bitcast i32* %b to double*
   %cmp = icmp eq double* %bc0, null
   br i1 %cmp, label %ret_undef0, label %if.end
 
 ret_undef0:
   ret double *undef

 attributes #0 = { noinline nounwind uwtable }
 
 ; BOTH-NOT: attributes #
 ; BOTH-DAG: attributes #{{[0-9]*}} = { nofree noinline norecurse nosync nounwind readnone uwtable willreturn }
 ; BOTH-DAG: attributes #{{[0-9]*}} = { nofree noinline nosync nounwind readnone uwtable }
 ; BOTH-DAG: attributes #{{[0-9]*}} = { nofree noinline noreturn nosync nounwind readonly uwtable }
 ; BOTH-DAG: attributes #{{[0-9]*}} = { noinline nounwind uwtable }
 ; BOTH-DAG: attributes #{{[0-9]*}} = { noreturn }
-; BOTH-DAG: attributes #{{[0-9]*}} = { nofree nosync willreturn }
-; BOTH-DAG: attributes #{{[0-9]*}} = { nofree nosync }
-; BOTH-DAG: attributes #{{[0-9]*}} = { nofree noreturn nosync }
+; BOTH-DAG: attributes #{{[0-9]*}} = { nofree noinline norecurse nosync nounwind readnone uwtable }
+; BOTH-DAG: attributes #{{[0-9]*}} = { nofree nosync readnone willreturn }
+; BOTH-DAG: attributes #{{[0-9]*}} = { nofree nosync readnone }
+; BOTH-DAG: attributes #{{[0-9]*}} = { nofree noreturn nosync readonly }
 ; BOTH-NOT: attributes #

llvm/test/Transforms/FunctionAttrs/dereferenceable.ll

 ; RUN: opt -attributor -attributor-manifest-internal --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=1 -S < %s | FileCheck %s --check-prefixes=ATTRIBUTOR
 
 
 declare void @deref_phi_user(i32* %a);
 
 ; TEST 1
 ; take mininimum of return values
 ;
 define i32* @test1(i32* dereferenceable(4) %0, double* dereferenceable(8) %1, i1 zeroext %2) local_unnamed_addr {
-; ATTRIBUTOR: define nonnull dereferenceable(4) i32* @test1(i32* nonnull dereferenceable(4) "no-capture-maybe-returned" %0, double* nonnull dereferenceable(8) "no-capture-maybe-returned" %1, i1 zeroext %2)
+; ATTRIBUTOR: define nonnull dereferenceable(4) i32* @test1(i32* nonnull readnone dereferenceable(4) "no-capture-maybe-returned" %0, double* nonnull readnone dereferenceable(8) "no-capture-maybe-returned" %1, i1 zeroext %2)
   %4 = bitcast double* %1 to i32*
   %5 = select i1 %2, i32* %0, i32* %4
   ret i32* %5
 }
 
 ; TEST 2
 define i32* @test2(i32* dereferenceable_or_null(4) %0, double* dereferenceable(8) %1, i1 zeroext %2) local_unnamed_addr {
-; ATTRIBUTOR: define dereferenceable_or_null(4) i32* @test2(i32* dereferenceable_or_null(4) "no-capture-maybe-returned" %0, double* nonnull dereferenceable(8) "no-capture-maybe-returned" %1, i1 zeroext %2)
+; ATTRIBUTOR: define dereferenceable_or_null(4) i32* @test2(i32* readnone dereferenceable_or_null(4) "no-capture-maybe-returned" %0, double* nonnull readnone dereferenceable(8) "no-capture-maybe-returned" %1, i1 zeroext %2)
   %4 = bitcast double* %1 to i32*
   %5 = select i1 %2, i32* %0, i32* %4
   ret i32* %5
 }
 
 ; TEST 3
 ; GEP inbounds
 define i32* @test3_1(i32* dereferenceable(8) %0) local_unnamed_addr {
-; ATTRIBUTOR: define nonnull dereferenceable(4) i32* @test3_1(i32* nonnull dereferenceable(8) "no-capture-maybe-returned" %0)
+; ATTRIBUTOR: define nonnull dereferenceable(4) i32* @test3_1(i32* nonnull readnone dereferenceable(8) "no-capture-maybe-returned" %0)
   %ret = getelementptr inbounds i32, i32* %0, i64 1
   ret i32* %ret
 }
 
 define i32* @test3_2(i32* dereferenceable_or_null(32) %0) local_unnamed_addr {
 ; FIXME: Argument should be mark dereferenceable because of GEP `inbounds`.
-; ATTRIBUTOR: define nonnull dereferenceable(16) i32* @test3_2(i32* dereferenceable_or_null(32) "no-capture-maybe-returned" %0)
+; ATTRIBUTOR: define nonnull dereferenceable(16) i32* @test3_2(i32* readnone dereferenceable_or_null(32) "no-capture-maybe-returned" %0)
   %ret = getelementptr inbounds i32, i32* %0, i64 4
   ret i32* %ret
 }
 
 define i32* @test3_3(i32* dereferenceable(8) %0, i32* dereferenceable(16) %1, i1 %2) local_unnamed_addr {
-; ATTRIBUTOR: define nonnull dereferenceable(4) i32* @test3_3(i32* nonnull dereferenceable(8) "no-capture-maybe-returned" %0, i32* nonnull dereferenceable(16) "no-capture-maybe-returned" %1, i1 %2) local_unnamed_addr
+; ATTRIBUTOR: define nonnull dereferenceable(4) i32* @test3_3(i32* nonnull readnone dereferenceable(8) "no-capture-maybe-returned" %0, i32* nonnull readnone dereferenceable(16) "no-capture-maybe-returned" %1, i1 %2) local_unnamed_addr
   %ret1 = getelementptr inbounds i32, i32* %0, i64 1
   %ret2 = getelementptr inbounds i32, i32* %1, i64 2
   %ret = select i1 %2, i32* %ret1, i32* %ret2
   ret i32* %ret
 }
 
 ; TEST 4
 ; Better than known in IR.
 
 define dereferenceable(4) i32* @test4(i32* dereferenceable(8) %0) local_unnamed_addr {
-; ATTRIBUTOR: define nonnull dereferenceable(8) i32* @test4(i32* nonnull returned dereferenceable(8) "no-capture-maybe-returned" %0)
+; ATTRIBUTOR: define nonnull dereferenceable(8) i32* @test4(i32* nonnull readnone returned dereferenceable(8) "no-capture-maybe-returned" %0)
   ret i32* %0
 }
 
 ; TEST 5
 ; loop in which dereferenceabily "grows"
 define void @deref_phi_growing(i32* dereferenceable(4000) %a) {
 entry:
   br label %for.cond

llvm/test/Transforms/FunctionAttrs/internal-noalias.ll

 ; RUN: opt -S -attributor -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=4 < %s | FileCheck %s
 
 define dso_local i32 @visible(i32* noalias %A, i32* noalias %B) #0 {
 entry:
   %call1 = call i32 @noalias_args(i32* %A, i32* %B)
   %call2 = call i32 @noalias_args_argmem(i32* %A, i32* %B)
   %add = add nsw i32 %call1, %call2
   ret i32 %add
 }
 
 ; FIXME: Should be something like this.
 ; define internal i32 @noalias_args(i32* nocapture readonly %A, i32* noalias nocapture readonly %B)
-; CHECK: define internal i32 @noalias_args(i32* nocapture %A, i32* nocapture %B)
+; CHECK: define internal i32 @noalias_args(i32* nocapture readonly %A, i32* nocapture readonly %B)
 
 define internal i32 @noalias_args(i32* %A, i32* %B) #0 {
 entry:
   %0 = load i32, i32* %A, align 4
   %1 = load i32, i32* %B, align 4
   %add = add nsw i32 %0, %1
   %call = call i32 @noalias_args_argmem(i32* %A, i32* %B)
   %add2 = add nsw i32 %add, %call
   ret i32 %add2
 }
 
 
 ; FIXME: Should be something like this.
 ; define internal i32 @noalias_args_argmem(i32* noalias nocapture readonly %A, i32* noalias nocapture readonly %B)
-; CHECK: define internal i32 @noalias_args_argmem(i32* nocapture %A, i32* nocapture %B)
+; CHECK: define internal i32 @noalias_args_argmem(i32* nocapture readonly %A, i32* nocapture readonly %B)
 ;
 define internal i32 @noalias_args_argmem(i32* %A, i32* %B) #1 {
 entry:
   %0 = load i32, i32* %A, align 4
   %1 = load i32, i32* %B, align 4
   %add = add nsw i32 %0, %1
   ret i32 %add
 }

llvm/test/Transforms/FunctionAttrs/liveness.ll

 }
 
 ; CHECK: Function Attrs: nofree norecurse nounwind uwtable willreturn
 define i32 @volatile_load(i32*) norecurse nounwind uwtable {
   %2 = load volatile i32, i32* %0, align 4
   ret i32 %2
 }
 
-; CHECK: Function Attrs: nofree norecurse nosync nounwind uwtable willreturn
-; CHECK-NEXT: define internal i32 @internal_load(i32* nocapture nonnull %0)
+; CHECK: Function Attrs: nofree norecurse nosync nounwind readonly uwtable willreturn
+; CHECK-NEXT: define internal i32 @internal_load(i32* nocapture nonnull readonly %0)
 define internal i32 @internal_load(i32*) norecurse nounwind uwtable {
   %2 = load i32, i32* %0, align 4
   ret i32 %2
 }
 ; TEST 1: Only first block is live.
 
 ; CHECK: Function Attrs: nofree noreturn nosync nounwind
-; CHECK-NEXT: define i32 @first_block_no_return(i32 %a, i32* nocapture nonnull %ptr1, i32* nocapture %ptr2)
+; CHECK-NEXT: define i32 @first_block_no_return(i32 %a, i32* nocapture nonnull readonly %ptr1, i32* nocapture readnone %ptr2)
 define i32 @first_block_no_return(i32 %a, i32* nonnull %ptr1, i32* %ptr2) #0 {
 entry:
   call i32 @internal_load(i32* %ptr1)
-  ; CHECK: call i32 @internal_load(i32* nocapture nonnull %ptr1)
+  ; CHECK: call i32 @internal_load(i32* nocapture nonnull readonly %ptr1)
   call void @no_return_call()
   ; CHECK: call void @no_return_call()
   ; CHECK-NEXT: unreachable
   ; CHECK-NEXT: }
   call i32 @dead_internal_func(i32 10)
   %cmp = icmp eq i32 %a, 0
   br i1 %cmp, label %cond.true, label %cond.false
 

 }
 
 ; TEST 2: cond.true is dead, but cond.end is not, since cond.false is live
 
 ; This is just an example. For example we can put a sync call in a
 ; dead block and check if it is deduced.
 
 ; CHECK: Function Attrs: nosync
-; CHECK-NEXT: define i32 @dead_block_present(i32 %a, i32* nocapture %ptr1)
+; CHECK-NEXT: define i32 @dead_block_present(i32 %a, i32* nocapture readnone %ptr1)
 define i32 @dead_block_present(i32 %a, i32* %ptr1) #0 {
 entry:
   %cmp = icmp eq i32 %a, 0
   br i1 %cmp, label %cond.true, label %cond.false
 
 cond.true:                                        ; preds = %entry
   call void @no_return_call()
   ; CHECK: call void @no_return_call()
cleanup:
   %res = landingpad { i8*, i32 }
   catch i8* null
   ret i32 0
 }
 
 ; TEST 6: Undefined behvior, taken from LangRef.
 ; FIXME: Should be able to detect undefined behavior.
 
-; CHECK: define void @ub(i32* nocapture %0)
+; CHECK: define void @ub(i32* nocapture writeonly %0)
 define void @ub(i32* %0) {
   %poison = sub nuw i32 0, 1           ; Results in a poison value.
   %still_poison = and i32 %poison, 0   ; 0, but also poison.
   %poison_yet_again = getelementptr i32, i32* %0, i32 %still_poison
   store i32 0, i32* %poison_yet_again  ; Undefined behavior due to store to poison.
   ret void
 }
 

 ; CHECK: define internal void @non_dead_d8()
 ; CHECK: define internal void @non_dead_d9()
 ; CHECK: define internal void @non_dead_d10()
 ; CHECK: define internal void @non_dead_d11()
 ; CHECK: define internal void @non_dead_d12()
 ; CHECK: define internal void @non_dead_d13()
 ; CHECK: define internal void @non_dead_d14()
 ; Verify we actually deduce information for these functions.
-; CHECK: Function Attrs: nofree nosync nounwind willreturn
+; CHECK: Function Attrs: nofree nosync nounwind readnone willreturn
 ; CHECK-NEXT: define internal void @non_dead_d15()
 ; CHECK-NOT: define internal void @dead_e
 
 
 declare void @blowup() noreturn
 define void @live_with_dead_entry() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
 ; CHECK:      define void @live_with_dead_entry(
 ; CHECK-NEXT: entry:

llvm/test/Transforms/FunctionAttrs/noalias_returned.ll

 
 5:                                                ; preds = %1, %4
   ret i8* %2
 }
 
 ; TEST 9
 ; Simple Argument Test
 define internal void @test9(i8* %a, i8* %b) {
-; CHECK: define internal void @test9(i8* noalias nocapture %a, i8* nocapture %b)
+; CHECK: define internal void @test9(i8* noalias nocapture readnone %a, i8* nocapture readnone %b)
   ret void
 }
 define void @test9_helper(i8* %a, i8* %b) {
   tail call void @test9(i8* noalias %a, i8* %b)
   tail call void @test9(i8* noalias %b, i8* noalias %a)
   ret void
 }
 

llvm/test/Transforms/FunctionAttrs/nocapture.ll

 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefixes=FNATTR,EITHER
 ; RUN: opt -passes=function-attrs -S < %s | FileCheck %s --check-prefixes=FNATTR,EITHER
 ; RUN: opt -attributor -attributor-manifest-internal -attributor-disable=false -S < %s | FileCheck %s --check-prefixes=ATTRIBUTOR,EITHER
 ; RUN: opt -passes=attributor -attributor-manifest-internal -attributor-disable=false -S < %s | FileCheck %s --check-prefixes=ATTRIBUTOR,EITHER
 
 @g = global i32* null   ; <i32**> [#uses=1]
 
 ; FNATTR: define i32* @c1(i32* readnone returned %q)
-; ATTRIBUTOR: define i32* @c1(i32* returned "no-capture-maybe-returned" %q)
+; ATTRIBUTOR: define i32* @c1(i32* readnone returned "no-capture-maybe-returned" %q)
 define i32* @c1(i32* %q) {
   ret i32* %q
 }
 
 ; EITHER: define void @c2(i32* %q)
 ; It would also be acceptable to mark %q as readnone. Update @c3 too.
 define void @c2(i32* %q) {
   store i32* %q, i32** @g
   ret void
 }
 
 ; EITHER: define void @c3(i32* %q)
 define void @c3(i32* %q) {
   call void @c2(i32* %q)
   ret void
 }
 
-; EITHER: define i1 @c4(i32* %q, i32 %bitno)
+; FNATTR: define i1 @c4(i32* %q, i32 %bitno)
+; ATTRIBUTOR: define i1 @c4(i32* readnone %q, i32 %bitno)
 define i1 @c4(i32* %q, i32 %bitno) {
   %tmp = ptrtoint i32* %q to i32
   %tmp2 = lshr i32 %tmp, %bitno
   %bit = trunc i32 %tmp2 to i1
   br i1 %bit, label %l1, label %l0
 l0:
   ret i1 0 ; escaping value not caught by def-use chaining.
 l1:

 
 ; EITHER: define void @nc3(void ()* nocapture %p)
 define void @nc3(void ()* %p) {
   call void %p()
   ret void
 }
 
 declare void @external(i8*) readonly nounwind
-; FNATTR: define void @nc4(i8* nocapture readonly %p)
-; ATTRIBUTOR: define void @nc4(i8* nocapture %p)
+; EITHER: define void @nc4(i8* nocapture readonly %p)
 define void @nc4(i8* %p) {
   call void @external(i8* %p)
   ret void
 }
 
 ; EITHER: define void @nc5(void (i8*)* nocapture %f, i8* nocapture %p)
 define void @nc5(void (i8*)* %f, i8* %p) {
   call void %f(i8* %p) readonly nounwind
   call void %f(i8* nocapture %p)
   ret void
 }
 
 ; FNATTR:     define void @test1_1(i8* nocapture readnone %x1_1, i8* %y1_1, i1 %c)
-; ATTRIBUTOR: define void @test1_1(i8* nocapture %x1_1, i8* nocapture %y1_1, i1 %c)
+; ATTRIBUTOR: define void @test1_1(i8* nocapture readnone %x1_1, i8* nocapture readnone %y1_1, i1 %c)
 ; It would be acceptable to add readnone to %y1_1 and %y1_2.
 define void @test1_1(i8* %x1_1, i8* %y1_1, i1 %c) {
   call i8* @test1_2(i8* %x1_1, i8* %y1_1, i1 %c)
   store i32* null, i32** @g
   ret void
 }
 
 ; FNATTR: define i8* @test1_2(i8* nocapture readnone %x1_2, i8* returned %y1_2, i1 %c)
-; ATTRIBUTOR: define i8* @test1_2(i8* nocapture %x1_2, i8* returned "no-capture-maybe-returned" %y1_2, i1 %c)
+; ATTRIBUTOR: define i8* @test1_2(i8* nocapture readnone %x1_2, i8* readnone returned "no-capture-maybe-returned" %y1_2, i1 %c)
 define i8* @test1_2(i8* %x1_2, i8* %y1_2, i1 %c) {
   br i1 %c, label %t, label %f
 t:
   call void @test1_1(i8* %x1_2, i8* %y1_2, i1 %c)
   store i32* null, i32** @g
   br label %f
 f:
   ret i8* %y1_2
 }
 
-; FNATTR: define void @test2(i8* nocapture readnone %x2)
-; ATTRIBUTOR: define void @test2(i8* nocapture %x2)
+; EITHER: define void @test2(i8* nocapture readnone %x2)
 define void @test2(i8* %x2) {
   call void @test2(i8* %x2)
   store i32* null, i32** @g
   ret void
 }
 
-; FNATTR: define void @test3(i8* nocapture readnone %x3, i8* nocapture readnone %y3, i8* nocapture readnone %z3)
-; ATTRIBUTOR: define void @test3(i8* nocapture %x3, i8* nocapture %y3, i8* nocapture %z3)
+; EITHER: define void @test3(i8* nocapture readnone %x3, i8* nocapture readnone %y3, i8* nocapture readnone %z3)
 define void @test3(i8* %x3, i8* %y3, i8* %z3) {
   call void @test3(i8* %z3, i8* %y3, i8* %x3)
   store i32* null, i32** @g
   ret void
 }
 
 ; FNATTR: define void @test4_1(i8* %x4_1, i1 %c)
-; ATTRIBUTOR: define void @test4_1(i8* nocapture %x4_1, i1 %c)
+; ATTRIBUTOR: define void @test4_1(i8* nocapture readnone %x4_1, i1 %c)
 define void @test4_1(i8* %x4_1, i1 %c) {
   call i8* @test4_2(i8* %x4_1, i8* %x4_1, i8* %x4_1, i1 %c)
   store i32* null, i32** @g
   ret void
 }
 
 ; FNATTR: define i8* @test4_2(i8* nocapture readnone %x4_2, i8* readnone returned %y4_2, i8* nocapture readnone %z4_2, i1 %c)
-; ATTRIBUTOR: define i8* @test4_2(i8* nocapture %x4_2, i8* returned "no-capture-maybe-returned" %y4_2, i8* nocapture %z4_2, i1 %c)
+; ATTRIBUTOR: define i8* @test4_2(i8* nocapture readnone %x4_2, i8* readnone returned "no-capture-maybe-returned" %y4_2, i8* nocapture readnone %z4_2, i1 %c)
 define i8* @test4_2(i8* %x4_2, i8* %y4_2, i8* %z4_2, i1 %c) {
   br i1 %c, label %t, label %f
 t:
   call void @test4_1(i8* null, i1 %c)
   store i32* null, i32** @g
   br label %f
 f:
   ret i8* %y4_2

 @g2 = global i8* null
 ; EITHER: define void @captureLaunder(i8* %p)
 define void @captureLaunder(i8* %p) {
   %b = call i8* @llvm.launder.invariant.group.p0i8(i8* %p)
   store i8* %b, i8** @g2
   ret void
 }
 
-; EITHER: @nocaptureStrip(i8* nocapture %p)
+; FNATTR: @nocaptureStrip(i8* nocapture %p)
+; ATTRIBUTOR: @nocaptureStrip(i8* nocapture writeonly %p)
 define void @nocaptureStrip(i8* %p) {
 entry:
   %b = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
   store i8 42, i8* %b
   ret void
 }
 
 @g3 = global i8* null
 ; EITHER: define void @captureStrip(i8* %p)
 define void @captureStrip(i8* %p) {
   %b = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
   store i8* %b, i8** @g3
   ret void
 }
 
-; FNATTR: define i1 @captureICmp(i32* readnone %x)
-; ATTRIBUTOR: define i1 @captureICmp(i32* %x)
+; EITHER: define i1 @captureICmp(i32* readnone %x)
 define i1 @captureICmp(i32* %x) {
   %1 = icmp eq i32* %x, null
   ret i1 %1
 }
 
-; FNATTR: define i1 @captureICmpRev(i32* readnone %x)
-; ATTRIBUTOR: define i1 @captureICmpRev(i32* %x)
+; EITHER: define i1 @captureICmpRev(i32* readnone %x)
 define i1 @captureICmpRev(i32* %x) {
   %1 = icmp eq i32* null, %x
   ret i1 %1
 }
 
-; FNATTR: define i1 @nocaptureInboundsGEPICmp(i32* nocapture readnone %x)
-; ATTRIBUTOR: define i1 @nocaptureInboundsGEPICmp(i32* nocapture %x)
+; EITHER: define i1 @nocaptureInboundsGEPICmp(i32* nocapture readnone %x)
 define i1 @nocaptureInboundsGEPICmp(i32* %x) {
   %1 = getelementptr inbounds i32, i32* %x, i32 5
   %2 = bitcast i32* %1 to i8*
   %3 = icmp eq i8* %2, null
   ret i1 %3
 }
 
-; FNATTR: define i1 @nocaptureInboundsGEPICmpRev(i32* nocapture readnone %x)
-; ATTRIBUTOR: define i1 @nocaptureInboundsGEPICmpRev(i32* nocapture %x)
+; EITHER: define i1 @nocaptureInboundsGEPICmpRev(i32* nocapture readnone %x)
 define i1 @nocaptureInboundsGEPICmpRev(i32* %x) {
   %1 = getelementptr inbounds i32, i32* %x, i32 5
   %2 = bitcast i32* %1 to i8*
   %3 = icmp eq i8* null, %2
   ret i1 %3
 }
 
-; FNATTR: define i1 @nocaptureDereferenceableOrNullICmp(i32* nocapture readnone dereferenceable_or_null(4) %x)
-; ATTRIBUTOR: define i1 @nocaptureDereferenceableOrNullICmp(i32* nocapture dereferenceable_or_null(4) %x)
+; EITHER: define i1 @nocaptureDereferenceableOrNullICmp(i32* nocapture readnone dereferenceable_or_null(4) %x)
 define i1 @nocaptureDereferenceableOrNullICmp(i32* dereferenceable_or_null(4) %x) {
   %1 = bitcast i32* %x to i8*
   %2 = icmp eq i8* %1, null
   ret i1 %2
 }
 
-; FNATTR: define i1 @captureDereferenceableOrNullICmp(i32* readnone dereferenceable_or_null(4) %x)
-; ATTRIBUTOR: define i1 @captureDereferenceableOrNullICmp(i32* dereferenceable_or_null(4) %x)
+; EITHER: define i1 @captureDereferenceableOrNullICmp(i32* readnone dereferenceable_or_null(4) %x)
 define i1 @captureDereferenceableOrNullICmp(i32* dereferenceable_or_null(4) %x) "null-pointer-is-valid"="true" {
   %1 = bitcast i32* %x to i8*
   %2 = icmp eq i8* %1, null
   ret i1 %2
 }
 
 declare i8* @llvm.launder.invariant.group.p0i8(i8*)
 declare i8* @llvm.strip.invariant.group.p0i8(i8*)

llvm/test/Transforms/FunctionAttrs/nofree-attributor.ll

 declare void @free(i8* nocapture) local_unnamed_addr #1
 declare noalias i8* @realloc(i8* nocapture, i64) local_unnamed_addr #0
 declare void @_ZdaPv(i8*) local_unnamed_addr #2
 
 
 ; TEST 1 (positive case)
 ; FNATTR: Function Attrs: noinline norecurse nounwind readnone uwtable
 ; FNATTR-NEXT: define void @only_return()
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @only_return()
 define void @only_return() #0 {
     ret void
 }
 
 
 ; TEST 2 (negative case)
 ; Only free

 ; }
 ; void mutual_recursion2(){
 ;     mutual_recursion1();
 ; }
 
 
 ; FNATTR: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTR-NEXT: define void @mutual_recursion1()
-; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @mutual_recursion1()
 define void @mutual_recursion1() #0 {
   call void @mutual_recursion2()
   ret void
 }
 
 ; FNATTR: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTR-NEXT: define void @mutual_recursion2()
-; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @mutual_recursion2()
 define void @mutual_recursion2() #0 {
   call void @mutual_recursion1()
   ret void
 }
 
 
 ; TEST 5

 ; FNATTR: Function Attrs: nofree noinline nounwind readnone uwtable
 ; FNATTR-NEXT: declare void @nofree_function()
 ; ATTRIBUTOR: Function Attrs:  nofree noinline nounwind readnone uwtable 
 ; ATTRIBUTOR-NEXT: declare void @nofree_function()
 declare void @nofree_function() nofree readnone #0
 
 ; FNATTR: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTR-NEXT: define void @call_nofree_function()
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @call_nofree_function()
 define void @call_nofree_function() #0 {
     tail call void @nofree_function()
     ret void
 }
 
 ; TEST 8 (negative case)
 ; Call function declaration without "nofree"

 ; FNATTRS-NEXT: declare float @llvm.floor.f32(float %0)
 ; ATTRIBUTOR: Function Attrs: nounwind readnone speculatable
 ; ATTRIBUTOR-NEXT: declare float @llvm.floor.f32(float)
 declare float @llvm.floor.f32(float)
 
 ; FNATTRS: Function Attrs: noinline nounwind uwtable
 ; FNATTRS-NEXT: define void @call_floor(float %a)
 ; FIXME: missing nofree
-; ATTRIBUTOR: Function Attrs: noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @call_floor(float %a)
 
 define void @call_floor(float %a) #0 {
     tail call float @llvm.floor.f32(float %a)
     ret void
 }
 
 ; TEST 11 (positive case)
 ; Check propagation.
 
 ; FNATTRS: Function Attrs: noinline nounwind uwtable
 ; FNATTRS-NEXT: define void @f1()
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @f1()
 define void @f1() #0 {
     tail call void @nofree_function()
     ret void
 }
 
 ; FNATTRS: Function Attrs: noinline nounwind uwtable
 ; FNATTRS-NEXT: define void @f2()
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @f2()
 define void @f2() #0 {
     tail call void @f1()
     ret void
 }
 
 
 attributes #0 = { nounwind uwtable noinline }
 attributes #1 = { nounwind }
 attributes #2 = { nobuiltin nounwind }

llvm/test/Transforms/FunctionAttrs/nonnull.ll

 define void @test13_helper() {
   %nonnullptr = tail call i8* @ret_nonnull()
   %maybenullptr = tail call i8* @unknown()
   tail call void @test13(i8* %nonnullptr, i8* %nonnullptr, i8* %maybenullptr)
   tail call void @test13(i8* %nonnullptr, i8* %maybenullptr, i8* %nonnullptr)
   ret void
 }
 define internal void @test13(i8* %a, i8* %b, i8* %c) {
-; ATTRIBUTOR: define internal void @test13(i8* nocapture nonnull %a, i8* nocapture %b, i8* nocapture %c) 
+; ATTRIBUTOR: define internal void @test13(i8* nocapture nonnull readnone %a, i8* nocapture readnone %b, i8* nocapture readnone %c) 
   ret void
 }
 
 declare nonnull i8* @nonnull()
 
 ; TEST 14
 ; Complex propagation
 ; Argument of f1, f2, f3 can be marked with nonnull.
 
 ; * Argument
 ; 1. In f1:bb6, %arg can be marked with nonnull because of the comparison in bb1
 ; 2. Because f2 is internal function, f2(i32* %arg) -> @f2(i32* nonnull %arg)
 ; 3. In f1:bb4 %tmp5 is nonnull and f3 is internal function. 
 ;    Then, f3(i32* %arg) -> @f3(i32* nonnull %arg)
 ; 4. We get nonnull in whole f1 call sites so f1(i32* %arg) -> @f1(i32* nonnull %arg)
 
 
 define internal i32* @f1(i32* %arg) {
-; FIXME: missing nonnull It should be nonnull @f1(i32* nonnull %arg)
-; ATTRIBUTOR: define internal nonnull i32* @f1(i32* %arg)
+; FIXME: missing nonnull It should be nonnull @f1(i32* nonnull readonly %arg)
+; ATTRIBUTOR: define internal nonnull i32* @f1(i32* readonly %arg)
 
 bb:
   %tmp = icmp eq i32* %arg, null
   br i1 %tmp, label %bb9, label %bb1
 
 bb1:                                              ; preds = %bb
   %tmp2 = load i32, i32* %arg, align 4
   %tmp3 = icmp eq i32 %tmp2, 0
bb9:                                              ; preds = %bb4, %bb
   ret i32* %tmp10
 }
 
 define internal i32* @f2(i32* %arg) {
 ; FIXME: missing nonnull. It should be nonnull @f2(i32* nonnull %arg) 
 ; ATTRIBUTOR: define internal nonnull i32* @f2(i32* %arg)
 bb:
 
-; FIXME: missing nonnull. It should be @f1(i32* nonnull %arg) 
-; ATTRIBUTOR:   %tmp = tail call nonnull i32* @f1(i32* %arg)
+; FIXME: missing nonnull. It should be @f1(i32* nonnull readonly %arg) 
+; ATTRIBUTOR:   %tmp = tail call nonnull i32* @f1(i32* readonly %arg)
   %tmp = tail call i32* @f1(i32* %arg)
   ret i32* %tmp
 }
 
 define dso_local noalias i32* @f3(i32* %arg) {
-; FIXME: missing nonnull. It should be nonnull @f3(i32* nonnull %arg) 
-; ATTRIBUTOR: define dso_local noalias i32* @f3(i32* %arg)
+; FIXME: missing nonnull. It should be nonnull @f3(i32* nonnull readonly %arg) 
+; ATTRIBUTOR: define dso_local noalias i32* @f3(i32* readonly %arg)
 bb:
-; FIXME: missing nonnull. It should be @f1(i32* nonnull %arg) 
-; ATTRIBUTOR:   %tmp = call i32* @f1(i32* %arg)
+; FIXME: missing nonnull. It should be @f1(i32* nonnull readonly %arg) 
+; ATTRIBUTOR:   %tmp = call i32* @f1(i32* readonly %arg)
   %tmp = call i32* @f1(i32* %arg)
   ret i32* null
 }
 
 ; TEST 15
 define void @f15(i8* %arg) {
 ; ATTRIBUTOR:   tail call void @use1(i8* nonnull dereferenceable(4) %arg)
 

 
 ; Make sure that an invoke works similarly to a call.
 
 declare i32 @esfp(...)
 
 define i1 @parent8(i8* %a, i8* %bogus1, i8* %b) personality i8* bitcast (i32 (...)* @esfp to i8*){
 ; FNATTR-LABEL: @parent8(i8* nonnull %a, i8* nocapture readnone %bogus1, i8* nonnull %b)
 ; FIXME : missing "nonnull", it should be @parent8(i8* nonnull %a, i8* %bogus1, i8* nonnull %b)
-; ATTRIBUTOR-LABEL: @parent8(i8* %a, i8* nocapture %bogus1, i8* %b)
+; ATTRIBUTOR-LABEL: @parent8(i8* %a, i8* nocapture readnone %bogus1, i8* %b)
 ; BOTH-NEXT:  entry:
 ; FNATTR-NEXT:    invoke void @use2nonnull(i8* %a, i8* %b)
 ; ATTRIBUTOR-NEXT:    invoke void @use2nonnull(i8* nonnull %a, i8* nonnull %b)
 ; BOTH-NEXT:    to label %cont unwind label %exc
 ; BOTH:       cont:
 ; BOTH-NEXT:    [[NULL_CHECK:%.*]] = icmp eq i8* %b, null
 ; BOTH-NEXT:    ret i1 [[NULL_CHECK]]
 ; BOTH:       exc:
define internal i32* @g2() {
   ret i32* inttoptr (i64 4 to i32*)
 }
 
 define  i32* @g1() {
  %c = call i32* @g2()
   ret i32* %c
 }
 
-; ATTRIBUTOR: define internal void @called_by_weak(i32* nocapture nonnull %a)
+; ATTRIBUTOR: define internal void @called_by_weak(i32* nocapture nonnull readnone %a)
 define internal void @called_by_weak(i32* %a) {
   ret void
 }
 
 ; Check we do not annotate the function interface of this weak function.
 ; ATTRIBUTOR: define weak_odr void @weak_caller(i32* nonnull %a)
 define weak_odr void @weak_caller(i32* nonnull %a) {
   call void @called_by_weak(i32* %a)
   ret void
 }
 
 attributes #0 = { "null-pointer-is-valid"="true" }

llvm/test/Transforms/FunctionAttrs/nosync.ll

 ; TEST 1
 ; non-convergent and readnone implies nosync
 %struct.RT = type { i8, [10 x [20 x i32]], i8 }
 %struct.ST = type { i32, double, %struct.RT }
 
 ; FNATTR: Function Attrs: norecurse nounwind optsize readnone ssp uwtable
 ; FNATTR-NEXT: define nonnull i32* @foo(%struct.ST* readnone %s)
 ; ATTRIBUTOR: Function Attrs: nofree nosync nounwind optsize readnone ssp uwtable
-; ATTRIBUTOR-NEXT: define nonnull i32* @foo(%struct.ST* "no-capture-maybe-returned" %s)
+; ATTRIBUTOR-NEXT: define nonnull i32* @foo(%struct.ST* readnone "no-capture-maybe-returned" %s)
 define i32* @foo(%struct.ST* %s) nounwind uwtable readnone optsize ssp {
 entry:
   %arrayidx = getelementptr inbounds %struct.ST, %struct.ST* %s, i64 1, i32 2, i32 1, i64 5, i64 13
   ret i32* %arrayidx
 }
 
 ; TEST 2
 ; atomic load with monotonic ordering

 ; atomic store with monotonic ordering.
 ; void store_monotonic(_Atomic int *num) {
 ;   atomic_load_explicit(num, memory_order_relaxed);
 ; }
 
 ; FNATTR: Function Attrs: nofree norecurse nounwind uwtable
 ; FNATTR-NEXT: define void @store_monotonic(i32* nocapture %0)
 ; ATTRIBUTOR: Function Attrs: nofree norecurse nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define void @store_monotonic(i32* nocapture %0)
+; ATTRIBUTOR-NEXT: define void @store_monotonic(i32* nocapture writeonly %0)
 define void @store_monotonic(i32* nocapture %0) norecurse nounwind uwtable {
   store atomic i32 10, i32* %0 monotonic, align 4
   ret void
 }
 
 ; TEST 4 - negative, should not deduce nosync
 ; atomic load with acquire ordering.
 ; int load_acquire(_Atomic int *num) {

 ; void load_release(_Atomic int *num) {
 ;   atomic_store_explicit(num, 10, memory_order_release);
 ; }
 
 ; FNATTR: Function Attrs: nofree norecurse nounwind uwtable
 ; FNATTR-NEXT: define void @load_release(i32* nocapture %0)
 ; ATTRIBUTOR: Function Attrs: nofree norecurse nounwind uwtable
 ; ATTRIBUTOR-NOT: nosync
-; ATTRIBUTOR-NEXT: define void @load_release(i32* nocapture %0)
+; ATTRIBUTOR-NEXT: define void @load_release(i32* nocapture writeonly %0)
 define void @load_release(i32* nocapture %0) norecurse nounwind uwtable {
   store atomic volatile i32 10, i32* %0 release, align 4
   ret void
 }
 
 ; TEST 6 - negative volatile, relaxed atomic
 
 ; FNATTR: Function Attrs: nofree norecurse nounwind uwtable
 ; FNATTR-NEXT: define void @load_volatile_release(i32* nocapture %0)
 ; ATTRIBUTOR: Function Attrs: nofree norecurse nounwind uwtable
 ; ATTRIBUTOR-NOT: nosync
-; ATTRIBUTOR-NEXT: define void @load_volatile_release(i32* nocapture %0)
+; ATTRIBUTOR-NEXT: define void @load_volatile_release(i32* nocapture writeonly %0)
 define void @load_volatile_release(i32* nocapture %0) norecurse nounwind uwtable {
   store atomic volatile i32 10, i32* %0 release, align 4
   ret void
 }
 
 ; TEST 7 - negative, should not deduce nosync
 ; volatile store.
 ; void volatile_store(volatile int *num) {
define void @call_might_sync() nounwind uwtable noinline {
   ret void
 }
 
 ; TEST 11 - positive, should deduce nosync
 ; volatile operation in same scc but dead. Call volatile_load defined in TEST 8.
 
 ; FNATTR: Function Attrs: nofree noinline nounwind uwtable
 ; FNATTR-NEXT: define i32 @scc1(i32* %0)
-; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define i32 @scc1(i32* nocapture %0)
+; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define i32 @scc1(i32* nocapture readnone %0)
 define i32 @scc1(i32* %0) noinline nounwind uwtable {
   tail call void @scc2(i32* %0);
   %val = tail call i32 @volatile_load(i32* %0);
   ret i32 %val;
 }
 
 ; FNATTR: Function Attrs: nofree noinline nounwind uwtable
 ; FNATTR-NEXT: define void @scc2(i32* %0)
-; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind uwtable
-; ATTRIBUTOR-NEXT: define void @scc2(i32* nocapture %0)
+; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind readnone uwtable
+; ATTRIBUTOR-NEXT: define void @scc2(i32* nocapture readnone %0)
 define void @scc2(i32* %0) noinline nounwind uwtable {
   tail call i32 @scc1(i32* %0);
   ret void;
 }
 
 ; TEST 12 - fences, negative
 ;
 ; void foo1(int *a, std::atomic<bool> flag){

 ; }
 
 %"struct.std::atomic" = type { %"struct.std::__atomic_base" }
 %"struct.std::__atomic_base" = type { i8 }
 
 ; FNATTR: Function Attrs: nofree norecurse nounwind
 ; FNATTR-NEXT: define void @foo1(i32* nocapture %0, %"struct.std::atomic"* nocapture %1)
 ; ATTRIBUTOR-NOT: nosync
-; ATTRIBUTOR: define void @foo1(i32* nocapture %0, %"struct.std::atomic"* nocapture %1)
+; ATTRIBUTOR: define void @foo1(i32* nocapture writeonly %0, %"struct.std::atomic"* nocapture writeonly %1)
 define void @foo1(i32* %0, %"struct.std::atomic"* %1) {
   store i32 100, i32* %0, align 4
   fence release
   %3 = getelementptr inbounds %"struct.std::atomic", %"struct.std::atomic"* %1, i64 0, i32 0, i32 0
   store atomic i8 1, i8* %3 monotonic, align 1
   ret void
 }
 
 ; FNATTR: Function Attrs: nofree norecurse nounwind
 ; FNATTR-NEXT: define void @bar(i32* nocapture readnone %0, %"struct.std::atomic"* nocapture readonly %1)
 ; ATTRIBUTOR-NOT: nosync
-; ATTRIBUTOR: define void @bar(i32* nocapture %0, %"struct.std::atomic"* nocapture %1)
+; ATTRIBUTOR: define void @bar(i32* nocapture readnone %0, %"struct.std::atomic"* nocapture readonly %1)
 define void @bar(i32* %0, %"struct.std::atomic"* %1) {
   %3 = getelementptr inbounds %"struct.std::atomic", %"struct.std::atomic"* %1, i64 0, i32 0, i32 0
   br label %4
 
 4:                                                ; preds = %4, %2
   %5 = load atomic i8, i8* %3  monotonic, align 1
   %6 = and i8 %5, 1
   %7 = icmp eq i8 %6, 0
   br i1 %7, label %4, label %8
 
 8:                                                ; preds = %4
   fence acquire
   ret void
 }
 
 ; TEST 13 - Fence syncscope("singlethread") seq_cst
 ; FNATTR: Function Attrs: nofree norecurse nounwind
 ; FNATTR-NEXT: define void @foo1_singlethread(i32* nocapture %0, %"struct.std::atomic"* nocapture %1)
 ; ATTRIBUTOR: Function Attrs: nofree nosync
-; ATTRIBUTOR: define void @foo1_singlethread(i32* nocapture %0, %"struct.std::atomic"* nocapture %1)
+; ATTRIBUTOR: define void @foo1_singlethread(i32* nocapture writeonly %0, %"struct.std::atomic"* nocapture writeonly %1)
 define void @foo1_singlethread(i32* %0, %"struct.std::atomic"* %1) {
   store i32 100, i32* %0, align 4
   fence syncscope("singlethread") release
   %3 = getelementptr inbounds %"struct.std::atomic", %"struct.std::atomic"* %1, i64 0, i32 0, i32 0
   store atomic i8 1, i8* %3 monotonic, align 1
   ret void
 }
 
 ; FNATTR: Function Attrs: nofree norecurse nounwind
 ; FNATTR-NEXT: define void @bar_singlethread(i32* nocapture readnone %0, %"struct.std::atomic"* nocapture readonly %1)
 ; ATTRIBUTOR: Function Attrs: nofree nosync
-; ATTRIBUTOR: define void @bar_singlethread(i32* nocapture %0, %"struct.std::atomic"* nocapture %1)
+; ATTRIBUTOR: define void @bar_singlethread(i32* nocapture readnone %0, %"struct.std::atomic"* nocapture readonly %1)
 define void @bar_singlethread(i32* %0, %"struct.std::atomic"* %1) {
   %3 = getelementptr inbounds %"struct.std::atomic", %"struct.std::atomic"* %1, i64 0, i32 0, i32 0
   br label %4
 
 4:                                                ; preds = %4, %2
   %5 = load atomic i8, i8* %3  monotonic, align 1
   %6 = and i8 %5, 1
   %7 = icmp eq i8 %6, 0
   br i1 %7, label %4, label %8
 
 8:                                                ; preds = %4
   fence syncscope("singlethread") acquire
   ret void
 }
 
 declare void @llvm.memcpy(i8* %dest, i8* %src, i32 %len, i1 %isvolatile)
 declare void @llvm.memset(i8* %dest, i8 %val, i32 %len, i1 %isvolatile)
 
 ; TEST 14 - negative, checking volatile intrinsics.
 
 ; It is odd to add nocapture but a result of the llvm.memcpy nocapture.
 ;
 ; ATTRIBUTOR: Function Attrs: nounwind
 ; ATTRIBUTOR-NOT: nosync
-; ATTRIBUTOR-NEXT: define i32 @memcpy_volatile(i8* nocapture %ptr1, i8* nocapture %ptr2)
+; ATTRIBUTOR-NEXT: define i32 @memcpy_volatile(i8* nocapture writeonly %ptr1, i8* nocapture readonly %ptr2)
 define i32 @memcpy_volatile(i8* %ptr1, i8* %ptr2) {
   call void @llvm.memcpy(i8* %ptr1, i8* %ptr2, i32 8, i1 1)
   ret i32 4
 }
 
 ; TEST 15 - positive, non-volatile intrinsic.
 
 ; It is odd to add nocapture but a result of the llvm.memset nocapture.
 ;
 ; ATTRIBUTOR: Function Attrs: nosync
-; ATTRIBUTOR-NEXT: define i32 @memset_non_volatile(i8* nocapture %ptr1, i8 %val)
+; ATTRIBUTOR-NEXT: define i32 @memset_non_volatile(i8* nocapture writeonly %ptr1, i8 %val)
 define i32 @memset_non_volatile(i8* %ptr1, i8 %val) {
   call void @llvm.memset(i8* %ptr1, i8 %val, i32 8, i1 0)
   ret i32 4
 }
 
 ; TEST 16 - negative, inline assembly.
 
 ; ATTRIBUTOR: define i32 @inline_asm_test(i32 %x)

llvm/test/Transforms/FunctionAttrs/read_write_returned_arguments_scc.ll

if.end:                                           ; preds = %entry
   br label %return
 
 return:                                           ; preds = %if.end, %if.then
   %retval.0 = phi i32* [ %call8, %if.end ], [ %r1, %if.then ]
   ret i32* %retval.0
 }
 
 ; CHECK: Function Attrs: nofree norecurse nosync nounwind
-; CHECK-NEXT: define i32* @external_sink_ret2_nrw(i32* readnone %n0, i32* nocapture readonly %r0, i32* returned "no-capture-maybe-returned" %w0)
+; CHECK-NEXT: define i32* @external_sink_ret2_nrw(i32* readnone %n0, i32* nocapture readonly %r0, i32* returned writeonly "no-capture-maybe-returned" %w0)
 define i32* @external_sink_ret2_nrw(i32* %n0, i32* %r0, i32* %w0) {
 entry:
   %tobool = icmp ne i32* %n0, null
   br i1 %tobool, label %if.end, label %if.then
 
 if.then:                                          ; preds = %entry
   br label %return
 

llvm/test/Transforms/FunctionAttrs/readattrs.ll

-; RUN: opt < %s -functionattrs -S | FileCheck %s
-; RUN: opt < %s -aa-pipeline=basic-aa -passes='cgscc(function-attrs)' -S | FileCheck %s
+; RUN: opt < %s -functionattrs -S | FileCheck %s --check-prefixes=CHECK,FNATTR
+; RUN: opt < %s -aa-pipeline=basic-aa -passes='cgscc(function-attrs)' -S | FileCheck %s --check-prefixes=CHECK,FNATTR
+; RUN: opt < %s -attributor -attributor-disable=false -S | FileCheck %s --check-prefixes=CHECK,ATTRIBUTOR
+; RUN: opt < %s -aa-pipeline=basic-aa -passes='attributor' -attributor-disable=false -S | FileCheck %s --check-prefixes=CHECK,ATTRIBUTOR
+
 @x = global i32 0
 
 declare void @test1_1(i8* %x1_1, i8* readonly %y1_1, ...)
 
 ; NOTE: readonly for %y1_2 would be OK here but not for the similar situation in test13.
 ;
-; CHECK: define void @test1_2(i8* %x1_2, i8* readonly %y1_2, i8* %z1_2)
+; FNATTR: define void @test1_2(i8* %x1_2, i8* readonly %y1_2, i8* %z1_2)
+; ATTRIBUTOR: define void @test1_2(i8* %x1_2, i8* %y1_2, i8* %z1_2)
 define void @test1_2(i8* %x1_2, i8* %y1_2, i8* %z1_2) {
   call void (i8*, i8*, ...) @test1_1(i8* %x1_2, i8* %y1_2, i8* %z1_2)
   store i32 0, i32* @x
   ret void
 }
 
-; CHECK: define i8* @test2(i8* readnone returned %p)
+; FNATTR: define i8* @test2(i8* readnone returned %p)
+; ATTRIBUTOR: define i8* @test2(i8* readnone returned %p)
 define i8* @test2(i8* %p) {
   store i32 0, i32* @x
   ret i8* %p
 }
 
 ; CHECK: define i1 @test3(i8* readnone %p, i8* readnone %q)
 define i1 @test3(i8* %p, i8* %q) {
   %A = icmp ult i8* %p, %q
   ret i1 %A
 }
 
 declare void @test4_1(i8* nocapture) readonly
 
 ; CHECK: define void @test4_2(i8* nocapture readonly %p)
 define void @test4_2(i8* %p) {
   call void @test4_1(i8* %p)
   ret void
 }
 
-; CHECK: define void @test5(i8** nocapture %p, i8* %q)
+; FNATTR: define void @test5(i8** nocapture %p, i8* %q)
+; ATTRIBUTOR: define void @test5(i8** nocapture writeonly %p, i8* %q)
 ; Missed optz'n: we could make %q readnone, but don't break test6!
 define void @test5(i8** %p, i8* %q) {
   store i8* %q, i8** %p
   ret void
 }
 
 declare void @test6_1()
-; CHECK: define void @test6_2(i8** nocapture %p, i8* %q)
+; FNATTR: define void @test6_2(i8** nocapture %p, i8* %q)
+; ATTRIBUTOR: define void @test6_2(i8** nocapture writeonly %p, i8* %q)
 ; This is not a missed optz'n.
 define void @test6_2(i8** %p, i8* %q) {
   store i8* %q, i8** %p
   call void @test6_1()
   ret void
 }
 
-; CHECK: define void @test7_1(i32* inalloca nocapture %a)
+; FNATTR: define void @test7_1(i32* inalloca nocapture %a)
+; ATTRIBUTOR: define void @test7_1(i32* inalloca nocapture writeonly %a)
 ; inalloca parameters are always considered written
 define void @test7_1(i32* inalloca %a) {
   ret void
 }
 
-; CHECK: define i32* @test8_1(i32* readnone returned %p)
+; FNATTR: define i32* @test8_1(i32* readnone returned %p)
+; ATTRIBUTOR: define i32* @test8_1(i32* readnone returned %p)
 define i32* @test8_1(i32* %p) {
 entry:
   ret i32* %p
 }
 
-; CHECK: define void @test8_2(i32* %p)
+; FNATTR: define void @test8_2(i32* %p)
+; ATTRIBUTOR: define void @test8_2(i32* nocapture writeonly %p)
 define void @test8_2(i32* %p) {
 entry:
   %call = call i32* @test8_1(i32* %p)
   store i32 10, i32* %call, align 4
   ret void
 }
 
 ; CHECK: declare void @llvm.masked.scatter

 ; CHECK: define i32 @volatile_load(
 ; CHECK-NOT: readonly
 ; CHECK: ret
 define i32 @volatile_load(i32* %p) {
   %load = load volatile i32, i32* %p
   ret i32 %load
 }
 
-declare void @escape_readonly_ptr(i8** %addr, i8* readnone %ptr)
-declare void @escape_readnone_ptr(i8** %addr, i8* readonly %ptr)
+declare void @escape_readnone_ptr(i8** %addr, i8* readnone %ptr)
+declare void @escape_readonly_ptr(i8** %addr, i8* readonly %ptr)
 
 ; The argument pointer %escaped_then_written cannot be marked readnone/only even
 ; though the only direct use, in @escape_readnone_ptr/@escape_readonly_ptr,
 ; is marked as readnone/only. However, the functions can write the pointer into
 ; %addr, causing the store to write to %escaped_then_written.
 ;
-; FIXME: This test currently exposes a bug!
+; FIXME: This test currently exposes a bug in functionattrs!
+;
+; FNATTR: define void @unsound_readnone(i8* nocapture readnone %ignored, i8* readnone %escaped_then_written)
+; FNATTR: define void @unsound_readonly(i8* nocapture readnone %ignored, i8* readonly %escaped_then_written)
 ;
-; BUG: define void @unsound_readnone(i8* %ignored, i8* readnone %escaped_then_written)
-; BUG: define void @unsound_readonly(i8* %ignored, i8* readonly %escaped_then_written)
+; ATTRIBUTOR: define void @unsound_readnone(i8* nocapture readnone %ignored, i8* %escaped_then_written)
+; ATTRIBUTOR: define void @unsound_readonly(i8* nocapture readnone %ignored, i8* %escaped_then_written)
 define void @unsound_readnone(i8* %ignored, i8* %escaped_then_written) {
   %addr = alloca i8*
   call void @escape_readnone_ptr(i8** %addr, i8* %escaped_then_written)
   %addr.ld = load i8*, i8** %addr
   store i8 0, i8* %addr.ld
   ret void
 }
 
 define void @unsound_readonly(i8* %ignored, i8* %escaped_then_written) {
   %addr = alloca i8*
   call void @escape_readonly_ptr(i8** %addr, i8* %escaped_then_written)
   %addr.ld = load i8*, i8** %addr
   store i8 0, i8* %addr.ld
   ret void
 }

llvm/test/Transforms/FunctionAttrs/willreturn.ll

 ; RUN: opt -functionattrs -S < %s | FileCheck %s --check-prefix=FNATTR
 ; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefix=ATTRIBUTOR
 
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 
 ; Test cases specifically designed for the "willreturn" function attribute.
 ; We use FIXME's to indicate problems and missing attributes.
 
 
 ; TEST 1 (positive case)
 ; FNATTR: Function Attrs: noinline norecurse nounwind readnone uwtable
 ; FNATTR-NEXT: define void @only_return()
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable willreturn
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable willreturn
 ; ATTRIBUTOR-NEXT: define void @only_return()
 define void @only_return() #0 {
     ret void
 }
 
 
 ; TEST 2 (positive & negative case)
 ; 2.1 (positive case)
 ; recursive function which will halt
 ; int fib(int n){
 ;    return n<=1? n : fib(n-1) + fib(n-2);
 ; }
 
 ; FNATTR: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTR-NEXT: define i32 @fib(i32 %0)
 ; FIXME: missing willreturn
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define i32 @fib(i32 %0) local_unnamed_addr
 define i32 @fib(i32 %0) local_unnamed_addr #0 {
   %2 = icmp slt i32 %0, 2
   br i1 %2, label %9, label %3
 
 ; <label>:3:                                      ; preds = %1
   %4 = add nsw i32 %0, -1
   %5 = tail call i32 @fib(i32 %4)

 ;   }
 ;   return fact_maybe_not_halt( n > 0 ? n-1 : n) * n;
 ; }
 ; fact_maybe_not(-1) doesn't stop.
 
 ; FNATTR: Function Attrs: noinline norecurse nounwind readnone uwtable
 ; FNATTR-NOT: willreturn
 ; FNATTR-NEXT: define i32 @fact_maybe_not_halt(i32 %0) local_unnamed_addr
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NOT: willreturn
 ; ATTRIBUTOR-NEXT: define i32 @fact_maybe_not_halt(i32 %0) local_unnamed_addr
 define i32 @fact_maybe_not_halt(i32 %0) local_unnamed_addr #0 {
   %2 = icmp eq i32 %0, 0
   br i1 %2, label %11, label %3
 
 ; <label>:3:                                      ; preds = %1, %3
   %4 = phi i32 [ %8, %3 ], [ %0, %1 ]

 ;     ans *= i;
 ;   }
 ;   return ans;
 ; }
 
 ; FIXME: missing willreturn
 ; FNATTR: Function Attrs: noinline norecurse nounwind readnone uwtable
 ; FNATTR-NEXT: define i32 @fact_loop(i32 %0)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define i32 @fact_loop(i32 %0) local_unnamed_addr
 define i32 @fact_loop(i32 %0) local_unnamed_addr #0 {
   %2 = icmp slt i32 %0, 1
   br i1 %2, label %3, label %5
 
 ; <label>:3:                                      ; preds = %5, %1
   %4 = phi i32 [ 1, %1 ], [ %8, %5 ]
   ret i32 %4

 ; }
 ; void mutual_recursion2(){
 ;     mutual_recursion1();
 ; }
 
 ; FNATTR: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTR-NOT: willreturn
 ; FNATTR-NEXT: define void @mutual_recursion1(i1 %c)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NOT: willreturn
 ; ATTRIBUTOR-NEXT: define void @mutual_recursion1(i1 %c)
 define void @mutual_recursion1(i1 %c) #0 {
   br i1 %c, label %rec, label %end
 rec:
   call void @mutual_recursion2(i1 %c)
   br label %end
 end:
   ret void
 }
 
 
 ; FNATTR: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTR-NOT: willreturn
 ; FNATTR-NEXT: define void @mutual_recursion2(i1 %c)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NOT: willreturn
 ; ATTRIBUTOR-NEXT: define void @mutual_recursion2(i1 %c)
 define void @mutual_recursion2(i1 %c) #0 {
   call void @mutual_recursion1(i1 %c)
   ret void
 }
 
 

 ; Call intrinsic function
 ; FIXME: missing willreturn
 ; FNATTRS: Function Attrs: noinline readnone speculatable
 ; FNATTRS-NEXT: declare float @llvm.floor.f32(float %0)
 ; ATTRIBUTOR: Function Attrs: nounwind readnone speculatable
 ; ATTRIBUTOR-NEXT: declare float @llvm.floor.f32(float)
 declare float @llvm.floor.f32(float)
 
-; FNATTRS: Function Attrs: noinline nounwind uwtable
+; FNATTRS: Function Attrs: noinline nounwind readnone uwtable
 ; FNATTRS-NEXT: define void @call_floor(float %a)
 ; FIXME: missing willreturn
-; ATTRIBUTOR: Function Attrs: noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define void @call_floor(float %a)
 define void @call_floor(float %a) #0 {
     tail call float @llvm.floor.f32(float %a)
     ret void
 }
 
 
 ; TEST 7 (negative case)

 ;        ans += p[i];
 ;    }
 ;    return ans;
 ; }
 
 ; FIXME: missing willreturn
 ; FNATTR: Function Attrs: noinline norecurse nounwind readonly uwtable
 ; FNATTR-NEXT: define i32 @loop_constant_trip_count(i32* nocapture readonly %0)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readonly uwtable
 ; ATTRIBUTOR-NEXT: define i32 @loop_constant_trip_count(i32* nocapture readonly %0)
 define i32 @loop_constant_trip_count(i32* nocapture readonly %0) #0 {
   br label %3
 
 ; <label>:2:                                      ; preds = %3
   ret i32 %8
 
 ; <label>:3:                                      ; preds = %3, %1

 ;     for(unsigned i = s;i != e;i+=offset){
 ;         ans += p[i];
 ;     }
 ;     return ans;
 ; }
 ; FNATTR: Function Attrs: noinline norecurse nounwind readonly uwtable
 ; FNATTR-NOT: willreturn
 ; FNATTR-NEXT: define i32 @loop_trip_count_unbound(i32 %0, i32 %1, i32* nocapture readonly %2, i32 %3) local_unnamed_addr
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readonly uwtable
 ; ATTRIBUTOR-NOT: willreturn
 ; ATTRIBUTOR-NEXT: define i32 @loop_trip_count_unbound(i32 %0, i32 %1, i32* nocapture readonly %2, i32 %3) local_unnamed_addr
 define i32 @loop_trip_count_unbound(i32 %0, i32 %1, i32* nocapture readonly %2, i32 %3) local_unnamed_addr #0 {
   %5 = icmp eq i32 %0, %1
   br i1 %5, label %6, label %8
 
 ; <label>:6:                                      ; preds = %8, %4
   %7 = phi i32 [ 0, %4 ], [ %14, %8 ]

 ;    }
 ;    return ans;
 ;  }
 
 
 ; FIXME: missing willreturn
 ; FNATTR: Function Attrs: noinline norecurse nounwind readonly uwtable
 ; FNATTR-NEXT: define i32 @loop_trip_dec(i32 %0, i32* nocapture readonly %1)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readonly uwtable
 ; ATTRIBUTOR-NEXT: define i32 @loop_trip_dec(i32 %0, i32* nocapture readonly %1) local_unnamed_addr
 
 define i32 @loop_trip_dec(i32 %0, i32* nocapture readonly %1) local_unnamed_addr #0 {
   %3 = icmp sgt i32 %0, -1
   br i1 %3, label %4, label %14
 
 ; <label>:4:                                      ; preds = %2
   %5 = sext i32 %0 to i64
; <label>:14:                                     ; preds = %6, %2
   ret i32 %15
 }
 
 ; TEST 14 (positive case)
 ; multiple return
 
 ; FNATTR: Function Attrs: noinline norecurse nounwind readnone uwtable
 ; FNATTR-NEXT: define i32 @multiple_return(i32 %a)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable willreturn
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable willreturn
 ; ATTRIBUTOR-NEXT: define i32 @multiple_return(i32 %a)
 define i32 @multiple_return(i32 %a) #0 {
   %b =  icmp eq i32 %a, 0
   br i1 %b, label %t, label %f
 
 t:
   ret i32 1
 f:

 unreachable_label:
   tail call void @exit(i32 0)
   unreachable
 }
 
 ; FIXME: missing willreturn
 ; FNATTR: Function Attrs: noinline nounwind uwtable
 ; FNATTR-NEXT: define i32 @unreachable_exit_positive2(i32 %0)
-; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NEXT: define i32 @unreachable_exit_positive2(i32 %0)
 define i32 @unreachable_exit_positive2(i32) local_unnamed_addr #0 {
   %2 = icmp slt i32 %0, 1
   br i1 %2, label %3, label %5
 
 ; <label>:3:                                      ; preds = %5, %1
   %4 = phi i32 [ 1, %1 ], [ %8, %5 ]
   ret i32 %4

 unreachable_label:
   tail call void @exit(i32 0)
   unreachable
 }
 
 ; FNATTR: Function Attrs: noinline nounwind uwtable
 ; FNATTR-NOT: willreturn
 ; FNATTR-NEXT: define void @unreachable_exit_negative2()
-; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind uwtable
+; ATTRIBUTOR: Function Attrs: nofree noinline noreturn nosync nounwind readnone uwtable
 ; ATTRIBUTOR-NOT: willreturn
 ; ATTRIBUTOR-NEXT: define void @unreachable_exit_negative2()
 define void @unreachable_exit_negative2() #0 {
 
   br label %L1
 L1:
   br label %L2
 L2: