r247199 - Generating assumption loads of vptr after ctor call (fixed)

Piotr Padlewski via cfe-commits cfe-commits at lists.llvm.org
Wed Sep 9 15:20:28 PDT 2015


Author: prazek
Date: Wed Sep  9 17:20:28 2015
New Revision: 247199

URL: http://llvm.org/viewvc/llvm-project?rev=247199&view=rev
Log:
Generating assumption loads of vptr after ctor call (fixed)

Generating call assume(icmp %vtable, %global_vtable) after constructor
call for devirtualization purposes.

For more info go to:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html

Edit:
Fixed version because of PR24479.
After this patch got reverted because of ScalarEvolution bug (D12719)
Merged after John McCall big patch (Added Address).

http://reviews.llvm.org/D11859

Added:
    cfe/trunk/test/CodeGenCXX/vtable-assume-load.cpp
Modified:
    cfe/trunk/lib/CodeGen/CGCXXABI.h
    cfe/trunk/lib/CodeGen/CGCall.cpp
    cfe/trunk/lib/CodeGen/CGClass.cpp
    cfe/trunk/lib/CodeGen/CGVTables.cpp
    cfe/trunk/lib/CodeGen/CodeGenFunction.h
    cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
    cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
    cfe/trunk/test/CodeGen/available-externally-hidden.cpp
    cfe/trunk/test/CodeGenCXX/ctor-globalopt.cpp
    cfe/trunk/test/CodeGenCXX/thunks.cpp
    cfe/trunk/test/CodeGenCXX/virtual-base-ctor.cpp
    cfe/trunk/test/CodeGenCXX/vtable-available-externally.cpp

Modified: cfe/trunk/lib/CodeGen/CGCXXABI.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXXABI.h?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXXABI.h (original)
+++ cfe/trunk/lib/CodeGen/CGCXXABI.h Wed Sep  9 17:20:28 2015
@@ -228,8 +228,10 @@ public:
   virtual void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) = 0;
   virtual llvm::GlobalVariable *getThrowInfo(QualType T) { return nullptr; }
 
-  virtual bool canEmitAvailableExternallyVTable(
-      const CXXRecordDecl *RD) const = 0;
+  /// \brief Determine whether it's possible to emit a vtable for \p RD, even
+  /// though we do not know that the vtable has been marked as used by semantic
+  /// analysis.
+  virtual bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const = 0;
 
   virtual void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) = 0;
 
@@ -355,13 +357,25 @@ public:
   virtual void emitVTableDefinitions(CodeGenVTables &CGVT,
                                      const CXXRecordDecl *RD) = 0;
 
+  /// Checks if ABI requires extra virtual offset for vtable field.
+  virtual bool
+  isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
+                                      CodeGenFunction::VPtr Vptr) = 0;
+
+  /// Checks if ABI requires to initilize vptrs for given dynamic class.
+  virtual bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) = 0;
+
+  /// Get the address point of the vtable for the given base subobject.
+  virtual llvm::Constant *
+  getVTableAddressPoint(BaseSubobject Base,
+                        const CXXRecordDecl *VTableClass) = 0;
+
   /// Get the address point of the vtable for the given base subobject while
-  /// building a constructor or a destructor. On return, NeedsVirtualOffset
-  /// tells if a virtual base adjustment is needed in order to get the offset
-  /// of the base subobject.
-  virtual llvm::Value *getVTableAddressPointInStructor(
-      CodeGenFunction &CGF, const CXXRecordDecl *RD, BaseSubobject Base,
-      const CXXRecordDecl *NearestVBase, bool &NeedsVirtualOffset) = 0;
+  /// building a constructor or a destructor.
+  virtual llvm::Value *
+  getVTableAddressPointInStructor(CodeGenFunction &CGF, const CXXRecordDecl *RD,
+                                  BaseSubobject Base,
+                                  const CXXRecordDecl *NearestVBase) = 0;
 
   /// Get the address point of the vtable for the given base subobject while
   /// building a constexpr.

Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCall.cpp Wed Sep  9 17:20:28 2015
@@ -1417,7 +1417,8 @@ void CodeGenModule::ConstructAttributeLi
 
     if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) {
       const FunctionProtoType *FPT = Fn->getType()->getAs<FunctionProtoType>();
-      if (FPT && FPT->isNothrow(getContext()))
+      if (FPT && !isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
+          FPT->isNothrow(getContext()))
         FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
       // Don't use [[noreturn]] or _Noreturn for a call to a virtual function.
       // These attributes are not inherited by overloads.

Modified: cfe/trunk/lib/CodeGen/CGClass.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGClass.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGClass.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGClass.cpp Wed Sep  9 17:20:28 2015
@@ -1984,12 +1984,14 @@ void CodeGenFunction::EmitCXXConstructor
                                              bool ForVirtualBase,
                                              bool Delegating, Address This,
                                              const CXXConstructExpr *E) {
+  const CXXRecordDecl *ClassDecl = D->getParent();
+
   // C++11 [class.mfct.non-static]p2:
   //   If a non-static member function of a class X is called for an object that
   //   is not of type X, or of a type derived from X, the behavior is undefined.
   // FIXME: Provide a source location here.
   EmitTypeCheck(CodeGenFunction::TCK_ConstructorCall, SourceLocation(),
-                This.getPointer(), getContext().getRecordType(D->getParent()));
+                This.getPointer(), getContext().getRecordType(ClassDecl));
 
   if (D->isTrivial() && D->isDefaultConstructor()) {
     assert(E->getNumArgs() == 0 && "trivial default ctor with args");
@@ -2005,7 +2007,7 @@ void CodeGenFunction::EmitCXXConstructor
     const Expr *Arg = E->getArg(0);
     QualType SrcTy = Arg->getType();
     Address Src = EmitLValue(Arg).getAddress();
-    QualType DestTy = getContext().getTypeDeclType(D->getParent());
+    QualType DestTy = getContext().getTypeDeclType(ClassDecl);
     EmitAggregateCopyCtor(This, Src, DestTy, SrcTy);
     return;
   }
@@ -2028,6 +2030,48 @@ void CodeGenFunction::EmitCXXConstructor
   const CGFunctionInfo &Info =
       CGM.getTypes().arrangeCXXConstructorCall(Args, D, Type, ExtraArgs);
   EmitCall(Info, Callee, ReturnValueSlot(), Args, D);
+
+  // Generate vtable assumptions if we're constructing a complete object
+  // with a vtable.  We don't do this for base subobjects for two reasons:
+  // first, it's incorrect for classes with virtual bases, and second, we're
+  // about to overwrite the vptrs anyway.
+  // We also have to make sure if we can refer to vtable:
+  // - If vtable is external then it's safe to use it (for available_externally
+  //   CGVTables will make sure if it can emit it).
+  // - Otherwise we can refer to vtable if it's safe to speculatively emit.
+  // FIXME: If vtable is used by ctor/dtor, we are always safe to refer to it.
+  if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
+      ClassDecl->isDynamicClass() && Type != Ctor_Base &&
+      (CGM.getVTables().isVTableExternal(ClassDecl) ||
+       CGM.getCXXABI().canSpeculativelyEmitVTable(ClassDecl)))
+    EmitVTableAssumptionLoads(ClassDecl, This);
+}
+
+void CodeGenFunction::EmitVTableAssumptionLoad(const VPtr &Vptr, Address This) {
+  llvm::Value *VTableGlobal =
+      CGM.getCXXABI().getVTableAddressPoint(Vptr.Base, Vptr.VTableClass);
+  if (!VTableGlobal)
+    return;
+
+  // We can just use the base offset in the complete class.
+  CharUnits NonVirtualOffset = Vptr.Base.getBaseOffset();
+
+  if (!NonVirtualOffset.isZero())
+    This =
+        ApplyNonVirtualAndVirtualOffset(*this, This, NonVirtualOffset, nullptr,
+                                        Vptr.VTableClass, Vptr.NearestVBase);
+
+  llvm::Value *VPtrValue = GetVTablePtr(This, VTableGlobal->getType());
+  llvm::Value *Cmp =
+      Builder.CreateICmpEQ(VPtrValue, VTableGlobal, "cmp.vtables");
+  Builder.CreateAssumption(Cmp);
+}
+
+void CodeGenFunction::EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl,
+                                                Address This) {
+  if (CGM.getCXXABI().doStructorsInitializeVPtrs(ClassDecl))
+    for (const VPtr &Vptr : getVTablePointers(ClassDecl))
+      EmitVTableAssumptionLoad(Vptr, This);
 }
 
 void
@@ -2193,24 +2237,12 @@ void CodeGenFunction::PushDestructorClea
   PushDestructorCleanup(D, Addr);
 }
 
-void
-CodeGenFunction::InitializeVTablePointer(BaseSubobject Base,
-                                         const CXXRecordDecl *NearestVBase,
-                                         CharUnits OffsetFromNearestVBase,
-                                         const CXXRecordDecl *VTableClass) {
-  const CXXRecordDecl *RD = Base.getBase();
-
-  // Don't initialize the vtable pointer if the class is marked with the
-  // 'novtable' attribute.
-  if ((RD == VTableClass || RD == NearestVBase) &&
-      VTableClass->hasAttr<MSNoVTableAttr>())
-    return;
-
+void CodeGenFunction::InitializeVTablePointer(const VPtr &Vptr) {
   // Compute the address point.
-  bool NeedsVirtualOffset;
   llvm::Value *VTableAddressPoint =
       CGM.getCXXABI().getVTableAddressPointInStructor(
-          *this, VTableClass, Base, NearestVBase, NeedsVirtualOffset);
+          *this, Vptr.VTableClass, Vptr.Base, Vptr.NearestVBase);
+
   if (!VTableAddressPoint)
     return;
 
@@ -2218,27 +2250,25 @@ CodeGenFunction::InitializeVTablePointer
   llvm::Value *VirtualOffset = nullptr;
   CharUnits NonVirtualOffset = CharUnits::Zero();
 
-  if (NeedsVirtualOffset) {
+  if (CGM.getCXXABI().isVirtualOffsetNeededForVTableField(*this, Vptr)) {
     // We need to use the virtual base offset offset because the virtual base
     // might have a different offset in the most derived class.
-    VirtualOffset =
-      CGM.getCXXABI().GetVirtualBaseClassOffset(*this, LoadCXXThisAddress(),
-                                                VTableClass, NearestVBase);
-    NonVirtualOffset = OffsetFromNearestVBase;
+
+    VirtualOffset = CGM.getCXXABI().GetVirtualBaseClassOffset(
+        *this, LoadCXXThisAddress(), Vptr.VTableClass, Vptr.NearestVBase);
+    NonVirtualOffset = Vptr.OffsetFromNearestVBase;
   } else {
     // We can just use the base offset in the complete class.
-    NonVirtualOffset = Base.getBaseOffset();
+    NonVirtualOffset = Vptr.Base.getBaseOffset();
   }
 
   // Apply the offsets.
   Address VTableField = LoadCXXThisAddress();
 
   if (!NonVirtualOffset.isZero() || VirtualOffset)
-    VTableField = ApplyNonVirtualAndVirtualOffset(*this, VTableField,
-                                                  NonVirtualOffset,
-                                                  VirtualOffset,
-                                                  VTableClass,
-                                                  NearestVBase);
+    VTableField = ApplyNonVirtualAndVirtualOffset(
+        *this, VTableField, NonVirtualOffset, VirtualOffset, Vptr.VTableClass,
+        Vptr.NearestVBase);
 
   // Finally, store the address point. Use the same LLVM types as the field to
   // support optimization.
@@ -2248,23 +2278,36 @@ CodeGenFunction::InitializeVTablePointer
           ->getPointerTo();
   VTableField = Builder.CreateBitCast(VTableField, VTablePtrTy->getPointerTo());
   VTableAddressPoint = Builder.CreateBitCast(VTableAddressPoint, VTablePtrTy);
+
   llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);
   CGM.DecorateInstruction(Store, CGM.getTBAAInfoForVTablePtr());
 }
 
-void
-CodeGenFunction::InitializeVTablePointers(BaseSubobject Base,
-                                          const CXXRecordDecl *NearestVBase,
-                                          CharUnits OffsetFromNearestVBase,
-                                          bool BaseIsNonVirtualPrimaryBase,
-                                          const CXXRecordDecl *VTableClass,
-                                          VisitedVirtualBasesSetTy& VBases) {
+CodeGenFunction::VPtrsVector
+CodeGenFunction::getVTablePointers(const CXXRecordDecl *VTableClass) {
+  CodeGenFunction::VPtrsVector VPtrsResult;
+  VisitedVirtualBasesSetTy VBases;
+  getVTablePointers(BaseSubobject(VTableClass, CharUnits::Zero()),
+                    /*NearestVBase=*/nullptr,
+                    /*OffsetFromNearestVBase=*/CharUnits::Zero(),
+                    /*BaseIsNonVirtualPrimaryBase=*/false, VTableClass, VBases,
+                    VPtrsResult);
+  return VPtrsResult;
+}
+
+void CodeGenFunction::getVTablePointers(BaseSubobject Base,
+                                        const CXXRecordDecl *NearestVBase,
+                                        CharUnits OffsetFromNearestVBase,
+                                        bool BaseIsNonVirtualPrimaryBase,
+                                        const CXXRecordDecl *VTableClass,
+                                        VisitedVirtualBasesSetTy &VBases,
+                                        VPtrsVector &Vptrs) {
   // If this base is a non-virtual primary base the address point has already
   // been set.
   if (!BaseIsNonVirtualPrimaryBase) {
     // Initialize the vtable pointer for this base.
-    InitializeVTablePointer(Base, NearestVBase, OffsetFromNearestVBase,
-                            VTableClass);
+    VPtr Vptr = {Base, NearestVBase, OffsetFromNearestVBase, VTableClass};
+    Vptrs.push_back(Vptr);
   }
 
   const CXXRecordDecl *RD = Base.getBase();
@@ -2302,11 +2345,10 @@ CodeGenFunction::InitializeVTablePointer
       BaseDeclIsNonVirtualPrimaryBase = Layout.getPrimaryBase() == BaseDecl;
     }
 
-    InitializeVTablePointers(BaseSubobject(BaseDecl, BaseOffset),
-                             I.isVirtual() ? BaseDecl : NearestVBase,
-                             BaseOffsetFromNearestVBase,
-                             BaseDeclIsNonVirtualPrimaryBase,
-                             VTableClass, VBases);
+    getVTablePointers(
+        BaseSubobject(BaseDecl, BaseOffset),
+        I.isVirtual() ? BaseDecl : NearestVBase, BaseOffsetFromNearestVBase,
+        BaseDeclIsNonVirtualPrimaryBase, VTableClass, VBases, Vptrs);
   }
 }
 
@@ -2316,11 +2358,9 @@ void CodeGenFunction::InitializeVTablePo
     return;
 
   // Initialize the vtable pointers for this class and all of its bases.
-  VisitedVirtualBasesSetTy VBases;
-  InitializeVTablePointers(BaseSubobject(RD, CharUnits::Zero()),
-                           /*NearestVBase=*/nullptr,
-                           /*OffsetFromNearestVBase=*/CharUnits::Zero(),
-                           /*BaseIsNonVirtualPrimaryBase=*/false, RD, VBases);
+  if (CGM.getCXXABI().doStructorsInitializeVPtrs(RD))
+    for (const VPtr &Vptr : getVTablePointers(RD))
+      InitializeVTablePointer(Vptr);
 
   if (RD->getNumVBases())
     CGM.getCXXABI().initializeHiddenVirtualInheritanceMembers(*this, RD);

Modified: cfe/trunk/lib/CodeGen/CGVTables.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGVTables.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGVTables.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGVTables.cpp Wed Sep  9 17:20:28 2015
@@ -696,7 +696,7 @@ CodeGenVTables::GenerateConstructionVTab
 static bool shouldEmitAvailableExternallyVTable(const CodeGenModule &CGM,
                                                 const CXXRecordDecl *RD) {
   return CGM.getCodeGenOpts().OptimizationLevel > 0 &&
-            CGM.getCXXABI().canEmitAvailableExternallyVTable(RD);
+         CGM.getCXXABI().canSpeculativelyEmitVTable(RD);
 }
 
 /// Compute the required linkage of the v-table for the given class.
@@ -846,11 +846,11 @@ bool CodeGenVTables::isVTableExternal(co
 /// we define that v-table?
 static bool shouldEmitVTableAtEndOfTranslationUnit(CodeGenModule &CGM,
                                                    const CXXRecordDecl *RD) {
-  // If vtable is internal then it has to be done
+  // If vtable is internal then it has to be done.
   if (!CGM.getVTables().isVTableExternal(RD))
     return true;
 
-  // If it's external then maybe we will need it as available_externally
+  // If it's external then maybe we will need it as available_externally.
   return shouldEmitAvailableExternallyVTable(CGM, RD);
 }
 

Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Wed Sep  9 17:20:28 2015
@@ -1354,21 +1354,27 @@ public:
   void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init,
                                ArrayRef<VarDecl *> ArrayIndexes);
 
-  /// InitializeVTablePointer - Initialize the vtable pointer of the given
-  /// subobject.
-  ///
-  void InitializeVTablePointer(BaseSubobject Base,
-                               const CXXRecordDecl *NearestVBase,
-                               CharUnits OffsetFromNearestVBase,
-                               const CXXRecordDecl *VTableClass);
+  /// Struct with all informations about dynamic [sub]class needed to set vptr.
+  struct VPtr {
+    BaseSubobject Base;
+    const CXXRecordDecl *NearestVBase;
+    CharUnits OffsetFromNearestVBase;
+    const CXXRecordDecl *VTableClass;
+  };
+
+  /// Initialize the vtable pointer of the given subobject.
+  void InitializeVTablePointer(const VPtr &vptr);
+
+  typedef llvm::SmallVector<VPtr, 4> VPtrsVector;
 
   typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
-  void InitializeVTablePointers(BaseSubobject Base,
-                                const CXXRecordDecl *NearestVBase,
-                                CharUnits OffsetFromNearestVBase,
-                                bool BaseIsNonVirtualPrimaryBase,
-                                const CXXRecordDecl *VTableClass,
-                                VisitedVirtualBasesSetTy& VBases);
+  VPtrsVector getVTablePointers(const CXXRecordDecl *VTableClass);
+
+  void getVTablePointers(BaseSubobject Base, const CXXRecordDecl *NearestVBase,
+                         CharUnits OffsetFromNearestVBase,
+                         bool BaseIsNonVirtualPrimaryBase,
+                         const CXXRecordDecl *VTableClass,
+                         VisitedVirtualBasesSetTy &VBases, VPtrsVector &vptrs);
 
   void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
 
@@ -1836,10 +1842,18 @@ public:
   // they are substantially the same.
   void EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
                                         const FunctionArgList &Args);
+
   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
                               bool ForVirtualBase, bool Delegating,
                               Address This, const CXXConstructExpr *E);
 
+  /// Emit assumption load for all bases. Requires to be be called only on
+  /// most-derived class and not under construction of the object.
+  void EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl, Address This);
+
+  /// Emit assumption that vptr load == global vtable.
+  void EmitVTableAssumptionLoad(const VPtr &vptr, Address This);
+
   void EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
                                       Address This, Address Src,
                                       const CXXConstructExpr *E);

Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Wed Sep  9 17:20:28 2015
@@ -243,10 +243,24 @@ public:
   void emitVTableDefinitions(CodeGenVTables &CGVT,
                              const CXXRecordDecl *RD) override;
 
+  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
+                                           CodeGenFunction::VPtr Vptr) override;
+
+  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
+    return true;
+  }
+
+  llvm::Constant *
+  getVTableAddressPoint(BaseSubobject Base,
+                        const CXXRecordDecl *VTableClass) override;
+
   llvm::Value *getVTableAddressPointInStructor(
       CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
-      BaseSubobject Base, const CXXRecordDecl *NearestVBase,
-      bool &NeedsVirtualOffset) override;
+      BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
+
+  llvm::Value *getVTableAddressPointInStructorWithVTT(
+      CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
+      BaseSubobject Base, const CXXRecordDecl *NearestVBase);
 
   llvm::Constant *
   getVTableAddressPointForConstExpr(BaseSubobject Base,
@@ -267,7 +281,7 @@ public:
 
   void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
 
-  bool canEmitAvailableExternallyVTable(const CXXRecordDecl *RD) const override;
+  bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override;
 
   void setThunkLinkage(llvm::Function *Thunk, bool ForVTable, GlobalDecl GD,
                        bool ReturnAdjustment) override {
@@ -1459,41 +1473,29 @@ void ItaniumCXXABI::emitVTableDefinition
   CGM.EmitVTableBitSetEntries(VTable, VTLayout);
 }
 
+bool ItaniumCXXABI::isVirtualOffsetNeededForVTableField(
+    CodeGenFunction &CGF, CodeGenFunction::VPtr Vptr) {
+  if (Vptr.NearestVBase == nullptr)
+    return false;
+  return NeedsVTTParameter(CGF.CurGD);
+}
+
 llvm::Value *ItaniumCXXABI::getVTableAddressPointInStructor(
     CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
-    const CXXRecordDecl *NearestVBase, bool &NeedsVirtualOffset) {
-  bool NeedsVTTParam = CGM.getCXXABI().NeedsVTTParameter(CGF.CurGD);
-  NeedsVirtualOffset = (NeedsVTTParam && NearestVBase);
-
-  llvm::Value *VTableAddressPoint;
-  if (NeedsVTTParam && (Base.getBase()->getNumVBases() || NearestVBase)) {
-    // Get the secondary vpointer index.
-    uint64_t VirtualPointerIndex =
-        CGM.getVTables().getSecondaryVirtualPointerIndex(VTableClass, Base);
-
-    /// Load the VTT.
-    llvm::Value *VTT = CGF.LoadCXXVTT();
-    if (VirtualPointerIndex)
-      VTT = CGF.Builder.CreateConstInBoundsGEP1_64(VTT, VirtualPointerIndex);
+    const CXXRecordDecl *NearestVBase) {
 
-    // And load the address point from the VTT.
-    VTableAddressPoint = CGF.Builder.CreateAlignedLoad(VTT, CGF.getPointerAlign());
-  } else {
-    llvm::Constant *VTable =
-        CGM.getCXXABI().getAddrOfVTable(VTableClass, CharUnits());
-    uint64_t AddressPoint = CGM.getItaniumVTableContext()
-                                .getVTableLayout(VTableClass)
-                                .getAddressPoint(Base);
-    VTableAddressPoint =
-        CGF.Builder.CreateConstInBoundsGEP2_64(VTable, 0, AddressPoint);
+  if ((Base.getBase()->getNumVBases() || NearestVBase != nullptr) &&
+      NeedsVTTParameter(CGF.CurGD)) {
+    return getVTableAddressPointInStructorWithVTT(CGF, VTableClass, Base,
+                                                  NearestVBase);
   }
-
-  return VTableAddressPoint;
+  return getVTableAddressPoint(Base, VTableClass);
 }
 
-llvm::Constant *ItaniumCXXABI::getVTableAddressPointForConstExpr(
-    BaseSubobject Base, const CXXRecordDecl *VTableClass) {
-  auto *VTable = getAddrOfVTable(VTableClass, CharUnits());
+llvm::Constant *
+ItaniumCXXABI::getVTableAddressPoint(BaseSubobject Base,
+                                     const CXXRecordDecl *VTableClass) {
+  llvm::GlobalValue *VTable = getAddrOfVTable(VTableClass, CharUnits());
 
   // Find the appropriate vtable within the vtable group.
   uint64_t AddressPoint = CGM.getItaniumVTableContext()
@@ -1508,6 +1510,30 @@ llvm::Constant *ItaniumCXXABI::getVTable
                                                       VTable, Indices);
 }
 
+llvm::Value *ItaniumCXXABI::getVTableAddressPointInStructorWithVTT(
+    CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
+    const CXXRecordDecl *NearestVBase) {
+  assert((Base.getBase()->getNumVBases() || NearestVBase != nullptr) &&
+         NeedsVTTParameter(CGF.CurGD) && "This class doesn't have VTT");
+
+  // Get the secondary vpointer index.
+  uint64_t VirtualPointerIndex =
+      CGM.getVTables().getSecondaryVirtualPointerIndex(VTableClass, Base);
+
+  /// Load the VTT.
+  llvm::Value *VTT = CGF.LoadCXXVTT();
+  if (VirtualPointerIndex)
+    VTT = CGF.Builder.CreateConstInBoundsGEP1_64(VTT, VirtualPointerIndex);
+
+  // And load the address point from the VTT.
+  return CGF.Builder.CreateAlignedLoad(VTT, CGF.getPointerAlign());
+}
+
+llvm::Constant *ItaniumCXXABI::getVTableAddressPointForConstExpr(
+    BaseSubobject Base, const CXXRecordDecl *VTableClass) {
+  return getVTableAddressPoint(Base, VTableClass);
+}
+
 llvm::GlobalVariable *ItaniumCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
                                                      CharUnits VPtrOffset) {
   assert(VPtrOffset.isZero() && "Itanium ABI only supports zero vptr offsets");
@@ -1583,8 +1609,7 @@ void ItaniumCXXABI::emitVirtualInheritan
   VTables.EmitVTTDefinition(VTT, CGM.getVTableLinkage(RD), RD);
 }
 
-bool ItaniumCXXABI::canEmitAvailableExternallyVTable(
-    const CXXRecordDecl *RD) const {
+bool ItaniumCXXABI::canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const {
   // We don't emit available_externally vtables if we are in -fapple-kext mode
   // because kext mode does not permit devirtualization.
   if (CGM.getLangOpts().AppleKext)

Modified: cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp Wed Sep  9 17:20:28 2015
@@ -127,8 +127,7 @@ public:
                                      QualType DestTy) override;
 
   bool EmitBadCastCall(CodeGenFunction &CGF) override;
-  bool canEmitAvailableExternallyVTable(
-      const CXXRecordDecl *RD) const override {
+  bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
     return false;
   }
 
@@ -236,10 +235,22 @@ public:
   void emitVTableDefinitions(CodeGenVTables &CGVT,
                              const CXXRecordDecl *RD) override;
 
+  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
+                                           CodeGenFunction::VPtr Vptr) override;
+
+  /// Don't initialize vptrs if dynamic class
+  /// is marked with with the 'novtable' attribute.
+  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
+    return !VTableClass->hasAttr<MSNoVTableAttr>();
+  }
+
+  llvm::Constant *
+  getVTableAddressPoint(BaseSubobject Base,
+                        const CXXRecordDecl *VTableClass) override;
+
   llvm::Value *getVTableAddressPointInStructor(
       CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
-      BaseSubobject Base, const CXXRecordDecl *NearestVBase,
-      bool &NeedsVirtualOffset) override;
+      BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
 
   llvm::Constant *
   getVTableAddressPointForConstExpr(BaseSubobject Base,
@@ -1608,14 +1619,15 @@ void MicrosoftCXXABI::emitVTableDefiniti
   }
 }
 
+bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
+    CodeGenFunction &CGF, CodeGenFunction::VPtr Vptr) {
+  return Vptr.NearestVBase != nullptr;
+}
+
 llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
     CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
-    const CXXRecordDecl *NearestVBase, bool &NeedsVirtualOffset) {
-  NeedsVirtualOffset = (NearestVBase != nullptr);
-
-  (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
-  VFTableIdTy ID(VTableClass, Base.getBaseOffset());
-  llvm::GlobalValue *VTableAddressPoint = VFTablesMap[ID];
+    const CXXRecordDecl *NearestVBase) {
+  llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
   if (!VTableAddressPoint) {
     assert(Base.getBase()->getNumVBases() &&
            !getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
@@ -1630,11 +1642,17 @@ static void mangleVFTableName(MicrosoftM
   MangleContext.mangleCXXVFTable(RD, VFPtr->MangledPath, Out);
 }
 
-llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
-    BaseSubobject Base, const CXXRecordDecl *VTableClass) {
+llvm::Constant *
+MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
+                                       const CXXRecordDecl *VTableClass) {
   (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
   VFTableIdTy ID(VTableClass, Base.getBaseOffset());
-  llvm::GlobalValue *VFTable = VFTablesMap[ID];
+  return VFTablesMap[ID];
+}
+
+llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
+    BaseSubobject Base, const CXXRecordDecl *VTableClass) {
+  llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
   assert(VFTable && "Couldn't find a vftable for the given base?");
   return VFTable;
 }
@@ -1644,6 +1662,7 @@ llvm::GlobalVariable *MicrosoftCXXABI::g
   // getAddrOfVTable may return 0 if asked to get an address of a vtable which
   // shouldn't be used in the given record type. We want to cache this result in
   // VFTablesMap, thus a simple zero check is not sufficient.
+
   VFTableIdTy ID(RD, VPtrOffset);
   VTablesMapTy::iterator I;
   bool Inserted;
@@ -1697,10 +1716,11 @@ llvm::GlobalVariable *MicrosoftCXXABI::g
   if (llvm::GlobalValue *VFTable =
           CGM.getModule().getNamedGlobal(VFTableName)) {
     VFTablesMap[ID] = VFTable;
-    return VTableAliasIsRequred
-               ? cast<llvm::GlobalVariable>(
-                     cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
-               : cast<llvm::GlobalVariable>(VFTable);
+    VTable = VTableAliasIsRequred
+                 ? cast<llvm::GlobalVariable>(
+                       cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
+                 : cast<llvm::GlobalVariable>(VFTable);
+    return VTable;
   }
 
   uint64_t NumVTableSlots =

Modified: cfe/trunk/test/CodeGen/available-externally-hidden.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/available-externally-hidden.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/available-externally-hidden.cpp (original)
+++ cfe/trunk/test/CodeGen/available-externally-hidden.cpp Wed Sep  9 17:20:28 2015
@@ -27,6 +27,6 @@ class TestSyncMessageFilter : public Syn
 };
 
 int main() {
-TestSyncMessageFilter*  f = new TestSyncMessageFilter;
+  TestSyncMessageFilter *f = new TestSyncMessageFilter;
   f->Send(new Message);
 }

Modified: cfe/trunk/test/CodeGenCXX/ctor-globalopt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/ctor-globalopt.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/ctor-globalopt.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/ctor-globalopt.cpp Wed Sep  9 17:20:28 2015
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm -o - %s -O1 | FileCheck %s --check-prefix=O1
+// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm -o - %s -O2 | opt - -S -globalopt -o - | FileCheck %s --check-prefix=O1
 // RUN: %clang_cc1 -triple %ms_abi_triple -emit-llvm -o - %s | FileCheck %s
-// RUN: %clang_cc1 -triple %ms_abi_triple -emit-llvm -o - %s -O1 | FileCheck %s --check-prefix=O1
+// RUN: %clang_cc1 -triple %ms_abi_triple -emit-llvm -o - %s -O2 | opt - -S -globalopt -o - | FileCheck %s --check-prefix=O1
 
 // Check that GlobalOpt can eliminate static constructors for simple implicit
 // constructors. This is a targeted integration test to make sure that LLVM's

Modified: cfe/trunk/test/CodeGenCXX/thunks.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/thunks.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/thunks.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/thunks.cpp Wed Sep  9 17:20:28 2015
@@ -1,5 +1,9 @@
-// RUN: %clang_cc1 %s -triple=x86_64-pc-linux-gnu -munwind-tables -emit-llvm -o - | FileCheck %s
-// RUN: %clang_cc1 %s -triple=x86_64-pc-linux-gnu -munwind-tables -emit-llvm -o - -O1 -disable-llvm-optzns | FileCheck %s
+// RUN: %clang_cc1 %s -triple=x86_64-pc-linux-gnu -munwind-tables -emit-llvm -o %t
+// RUN: %clang_cc1 %s -triple=x86_64-pc-linux-gnu -munwind-tables -emit-llvm -o %t.opt -O1 -disable-llvm-optzns
+// RUN: FileCheck %s < %t
+// RUN: FileCheck %s < %t.opt
+// RUN: FileCheck --check-prefix=CHECK-NONOPT %s < %t
+// RUN: FileCheck --check-prefix=CHECK-OPT %s < %t.opt
 
 namespace Test1 {
 
@@ -380,13 +384,25 @@ D::~D() {}
 
 /**** The following has to go at the end of the file ****/
 
+// checking without opt
+// CHECK-NONOPT-LABEL: define internal void @_ZThn8_N6Test4B12_GLOBAL__N_11C1fEv(
+// CHECK-NONOPT-NOT: comdat
+
+// This is from Test5:
+// CHECK-NONOPT-LABEL: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
+
+// This is from Test10:
+// CHECK-NONOPT-LABEL: define linkonce_odr void @_ZN6Test101C3fooEv
+// CHECK-NONOPT-LABEL: define linkonce_odr void @_ZThn8_N6Test101C3fooEv
+
+// Checking with opt
+// CHECK-OPT-LABEL: define internal void @_ZThn8_N6Test4B12_GLOBAL__N_11C1fEv(%"struct.Test4B::(anonymous namespace)::C"* %this) unnamed_addr #0 align 2
+
 // This is from Test5:
-// CHECK-LABEL: define internal void @_ZThn8_N6Test4B12_GLOBAL__N_11C1fEv(
-// CHECK-NOT: comdat
-// CHECK-LABEL: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
+// CHECK-OPT-LABEL: define linkonce_odr void @_ZTv0_n24_N5Test51B1fEv
 
 // This is from Test10:
-// CHECK-LABEL: define linkonce_odr void @_ZN6Test101C3fooEv
-// CHECK-LABEL: define linkonce_odr void @_ZThn8_N6Test101C3fooEv
+// CHECK-OPT-LABEL: define linkonce_odr void @_ZN6Test101C3fooEv
+// CHECK-OPT-LABEL: define linkonce_odr void @_ZThn8_N6Test101C3fooEv
 
 // CHECK: attributes [[NUW]] = { nounwind uwtable{{.*}} }

Modified: cfe/trunk/test/CodeGenCXX/virtual-base-ctor.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/virtual-base-ctor.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/virtual-base-ctor.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/virtual-base-ctor.cpp Wed Sep  9 17:20:28 2015
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -emit-llvm -triple %itanium_abi_triple -o - -O2 | FileCheck %s
+// RUN: %clang_cc1 %s -emit-llvm -triple %itanium_abi_triple -o - -O2 | opt - -S -globalopt -o - | FileCheck %s
 
 struct B;
 extern B x;

Added: cfe/trunk/test/CodeGenCXX/vtable-assume-load.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/vtable-assume-load.cpp?rev=247199&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/vtable-assume-load.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/vtable-assume-load.cpp Wed Sep  9 17:20:28 2015
@@ -0,0 +1,293 @@
+// RUN: %clang_cc1 %s -triple x86_64-apple-darwin10 -emit-llvm -o %t.ll -O1 -disable-llvm-optzns -fms-extensions
+// RUN: %clang_cc1 %s -triple i686-pc-win32 -emit-llvm -o %t.ms.ll -O1 -disable-llvm-optzns -fms-extensions
+
+// RUN: FileCheck --check-prefix=CHECK1 --input-file=%t.ll %s
+// RUN: FileCheck --check-prefix=CHECK2 --input-file=%t.ll %s
+// RUN: FileCheck --check-prefix=CHECK3 --input-file=%t.ll %s
+// RUN: FileCheck --check-prefix=CHECK4 --input-file=%t.ll %s
+// RUN: FileCheck --check-prefix=CHECK-MS --input-file=%t.ms.ll %s
+// RUN: FileCheck --check-prefix=CHECK6 --input-file=%t.ll %s
+// RUN: FileCheck --check-prefix=CHECK7 --input-file=%t.ll %s
+// RUN: FileCheck --check-prefix=CHECK8 --input-file=%t.ll %s
+namespace test1 {
+
+struct A {
+  A();
+  virtual void foo();
+};
+
+struct B : A {
+  virtual void foo();
+};
+
+void g(A *a) { a->foo(); }
+
+// CHECK1-LABEL: define void @_ZN5test14fooAEv()
+// CHECK1: call void @_ZN5test11AC1Ev(%"struct.test1::A"*
+// CHECK1: %[[VTABLE:.*]] = load i8**, i8*** %{{.*}}
+// CHECK1: %[[CMP:.*]] = icmp eq i8** %[[VTABLE]], getelementptr inbounds ([3 x i8*], [3 x i8*]* @_ZTVN5test11AE, i64 0, i64 2)
+// CHECK1: call void @llvm.assume(i1 %[[CMP]])
+// CHECK1-LABEL: }
+
+void fooA() {
+  A a;
+  g(&a);
+}
+
+// CHECK1-LABEL: define void @_ZN5test14fooBEv()
+// CHECK1: call void @_ZN5test11BC1Ev(%"struct.test1::B"* %{{.*}})
+// CHECK1: %[[VTABLE:.*]] = load i8**, i8*** %{{.*}}
+// CHECK1: %[[CMP:.*]] = icmp eq i8** %[[VTABLE]], getelementptr inbounds ([3 x i8*], [3 x i8*]* @_ZTVN5test11BE, i64 0, i64 2)
+// CHECK1: call void @llvm.assume(i1 %[[CMP]])
+// CHECK1-LABEL: }
+
+void fooB() {
+  B b;
+  g(&b);
+}
+// there should not be any assumes in the ctor that calls base ctor
+// CHECK1-LABEL: define linkonce_odr void @_ZN5test11BC2Ev(%"struct.test1::B"*
+// CHECK1-NOT: @llvm.assume(
+// CHECK1-LABEL: }
+}
+namespace test2 {
+struct A {
+  A();
+  virtual void foo();
+};
+
+struct B {
+  B();
+  virtual void bar();
+};
+
+struct C : A, B {
+  C();
+  virtual void foo();
+};
+void g(A *a) { a->foo(); }
+void h(B *b) { b->bar(); }
+
+// CHECK2-LABEL: define void @_ZN5test24testEv()
+// CHECK2: call void @_ZN5test21CC1Ev(%"struct.test2::C"*
+// CHECK2: %[[VTABLE:.*]] = load i8**, i8*** {{.*}}
+// CHECK2: %[[CMP:.*]] = icmp eq i8** %[[VTABLE]], getelementptr inbounds ([6 x i8*], [6 x i8*]* @_ZTVN5test21CE, i64 0, i64 2)
+// CHECK2: call void @llvm.assume(i1 %[[CMP]])
+
+// CHECK2: %[[V2:.*]] = bitcast %"struct.test2::C"* %{{.*}} to i8*
+// CHECK2: %[[ADD_PTR:.*]] = getelementptr inbounds i8, i8* %[[V2]], i64 8
+// CHECK2: %[[V3:.*]] = bitcast i8* %[[ADD_PTR]] to i8***
+// CHECK2: %[[VTABLE2:.*]] = load i8**, i8*** %[[V3]]
+// CHECK2: %[[CMP2:.*]] = icmp eq i8** %[[VTABLE2]], getelementptr inbounds ([6 x i8*], [6 x i8*]* @_ZTVN5test21CE, i64 0, i64 5)
+// CHECK2: call void @llvm.assume(i1 %[[CMP2]])
+
+// CHECK2: call void @_ZN5test21gEPNS_1AE(
+// CHECK2-LABEL: }
+
+void test() {
+  C c;
+  g(&c);
+  h(&c);
+}
+}
+
+namespace test3 {
+struct A {
+  A();
+};
+
+struct B : A {
+  B();
+  virtual void foo();
+};
+
+struct C : virtual A, B {
+  C();
+  virtual void foo();
+};
+void g(B *a) { a->foo(); }
+
+// CHECK3-LABEL: define void @_ZN5test34testEv()
+// CHECK3: call void @_ZN5test31CC1Ev(%"struct.test3::C"*
+// CHECK3: %[[CMP:.*]] = icmp eq i8** %{{.*}}, getelementptr inbounds ([4 x i8*], [4 x i8*]* @_ZTVN5test31CE, i64 0, i64 3)
+// CHECK3: call void @llvm.assume(i1 %[[CMP]])
+// CHECK3-LABLEL: }
+void test() {
+  C c;
+  g(&c);
+}
+} // test3
+
+namespace test4 {
+struct A {
+  A();
+  virtual void foo();
+};
+
+struct B : virtual A {
+  B();
+  virtual void foo();
+};
+struct C : B {
+  C();
+  virtual void foo();
+};
+
+void g(C *c) { c->foo(); }
+
+// CHECK4-LABEL: define void @_ZN5test44testEv()
+// CHECK4: call void @_ZN5test41CC1Ev(%"struct.test4::C"*
+// CHECK4: %[[VTABLE:.*]] = load i8**, i8*** %{{.*}}
+// CHECK4: %[[CMP:.*]] = icmp eq i8** %[[VTABLE]], getelementptr inbounds ([5 x i8*], [5 x i8*]* @_ZTVN5test41CE, i64 0, i64 4)
+// CHECK4: call void @llvm.assume(i1 %[[CMP]]
+
+// CHECK4: %[[VTABLE2:.*]] = load i8**, i8*** %{{.*}}
+// CHECK4: %[[CMP2:.*]] = icmp eq i8** %[[VTABLE2]], getelementptr inbounds ([5 x i8*], [5 x i8*]* @_ZTVN5test41CE, i64 0, i64 4)
+// CHECK4: call void @llvm.assume(i1 %[[CMP2]])
+// CHECK4-LABEL: }
+
+void test() {
+  C c;
+  g(&c);
+}
+} // test4
+
+namespace testMS {
+
+struct __declspec(novtable) S {
+  virtual void foo();
+};
+
+void g(S &s) { s.foo(); }
+
+// if struct has novtable specifier, then we can't generate assumes
+// CHECK-MS-LABEL: define void @"\01?test at testMS@@YAXXZ"()
+// CHECK-MS: call x86_thiscallcc %"struct.testMS::S"* @"\01??0S at testMS@@QAE at XZ"(
+// CHECK-MS-NOT: @llvm.assume
+// CHECK-MS-LABEL: }
+
+void test() {
+  S s;
+  g(s);
+}
+
+} // testMS
+
+namespace test6 {
+// CHECK6: @_ZTVN5test61AE = external
+struct A {
+  A();
+  virtual void foo();
+  virtual ~A() {}
+};
+struct B : A {
+  B();
+};
+// Because A's vtable is external, it's safe to generate assumption loads.
+// CHECK6-LABEL: define void @_ZN5test61gEv()
+// CHECK6: call void @_ZN5test61AC1Ev(
+// CHECK6: call void @llvm.assume(
+
+// We can't emit assumption loads for B, because if we would refer to vtable
+// it would refer to functions that will not be able to find (like implicit
+// inline destructor).
+
+// CHECK6-LABEL:   call void @_ZN5test61BC1Ev(
+// CHECK6-NOT: call void @llvm.assume(
+// CHECK6-LABEL: }
+void g() {
+  A *a = new A;
+  B *b = new B;
+}
+}
+
+namespace test7 {
+// Because A's key function is defined here, vtable is generated in this TU
+// CHECK7: @_ZTVN5test71AE = unnamed_addr constant
+struct A {
+  A();
+  virtual void foo();
+  virtual void bar();
+};
+void A::foo() {}
+
+// CHECK7-LABEL: define void @_ZN5test71gEv()
+// CHECK7: call void @_ZN5test71AC1Ev(
+// CHECK7: call void @llvm.assume(
+// CHECK7-LABEL: }
+void g() {
+  A *a = new A();
+  a->bar();
+}
+}
+
+namespace test8 {
+
+struct A {
+  virtual void foo();
+  virtual void bar();
+};
+
+// CHECK8-DAG: @_ZTVN5test81BE = available_externally unnamed_addr constant
+struct B : A {
+  B();
+  void foo();
+  void bar();
+};
+
+// CHECK8-DAG: @_ZTVN5test81CE = linkonce_odr unnamed_addr constant
+struct C : A {
+  C();
+  void bar();
+  void foo() {}
+};
+inline void C::bar() {}
+
+// CHECK8-DAG: @_ZTVN5test81DE = external unnamed_addr constant
+struct D : A {
+  D();
+  void foo();
+  void inline bar();
+};
+void D::bar() {}
+
+// CHECK8-DAG: @_ZTVN5test81EE = linkonce_odr unnamed_addr constant
+struct E : A {
+  E();
+};
+
+// CHECK8-LABEL: define void @_ZN5test81bEv()
+// CHECK8: call void @llvm.assume(
+// CHECK8-LABEL: }
+void b() {
+  B b;
+  b.bar();
+}
+
+// FIXME: C has inline virtual functions which prohibits as from generating
+// assumption loads, but because vtable is generated in this TU (key function
+// defined here) it would be correct to refer to it.
+// CHECK8-LABEL: define void @_ZN5test81cEv()
+// CHECK8-NOT: call void @llvm.assume(
+// CHECK8-LABEL: }
+void c() {
+  C c;
+  c.bar();
+}
+
+// CHECK8-LABEL: define void @_ZN5test81dEv()
+// CHECK8: call void @llvm.assume(
+// CHECK8-LABEL: }
+void d() {
+  D d;
+  d.bar();
+}
+
+// CHECK8-LABEL: define void @_ZN5test81eEv()
+// CHECK8: call void @llvm.assume(
+// CHECK8-LABEL: }
+void e() {
+  E e;
+  e.bar();
+}
+}

Modified: cfe/trunk/test/CodeGenCXX/vtable-available-externally.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/vtable-available-externally.cpp?rev=247199&r1=247198&r2=247199&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/vtable-available-externally.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/vtable-available-externally.cpp Wed Sep  9 17:20:28 2015
@@ -184,10 +184,10 @@ void f() {
 }  // Test8
 
 namespace Test9 {
-// all virtual functions are outline, so we can assume that it will
-// be generated in translation unit where foo is defined
-// CHECK-TEST9: @_ZTVN5Test91AE = available_externally unnamed_addr constant
-// CHECK-TEST9: @_ZTVN5Test91BE = available_externally unnamed_addr constant
+// All virtual functions are outline, so we can assume that it will
+// be generated in translation unit where foo is defined.
+// CHECK-TEST9-DAG: @_ZTVN5Test91AE = available_externally unnamed_addr constant
+// CHECK-TEST9-DAG: @_ZTVN5Test91BE = available_externally unnamed_addr constant
 struct A {
   virtual void foo();
   virtual void bar();
@@ -210,22 +210,22 @@ void g() {
 namespace Test10 {
 
 // because A's key function is defined here, vtable is generated in this TU
-// CHECK-TEST10: @_ZTVN6Test101AE = unnamed_addr constant
+// CHECK-TEST10-DAG: @_ZTVN6Test101AE = unnamed_addr constant
 struct A {
   virtual void foo();
   virtual void bar();
 };
 void A::foo() {}
 
-// Because key function is inline we will generate vtable as linkonce_odr
-// CHECK-TEST10: @_ZTVN6Test101DE = linkonce_odr unnamed_addr constant
+// Because key function is inline we will generate vtable as linkonce_odr.
+// CHECK-TEST10-DAG: @_ZTVN6Test101DE = linkonce_odr unnamed_addr constant
 struct D : A {
   void bar();
 };
 inline void D::bar() {}
 
-// because B has outline key function then we can refer to
-// CHECK-TEST10: @_ZTVN6Test101BE = available_externally unnamed_addr constant
+// Because B has outline all virtual functions, we can refer to them.
+// CHECK-TEST10-DAG: @_ZTVN6Test101BE = available_externally unnamed_addr constant
 struct B : A {
   void foo();
   void bar();
@@ -233,8 +233,8 @@ struct B : A {
 
 // C's key function (car) is outline, but C has inline virtual function so we
 // can't guarantee that we will be able to refer to bar from name
-// so (at the moment) we can't emit vtable available_externally
-// CHECK-TEST10: @_ZTVN6Test101CE = external unnamed_addr constant
+// so (at the moment) we can't emit vtable available_externally.
+// CHECK-TEST10-DAG: @_ZTVN6Test101CE = external unnamed_addr constant
 struct C : A {
   void bar() {}               // defined in body - not key function
   virtual inline void gar();  // inline in body - not key function
@@ -242,7 +242,7 @@ struct C : A {
 };
 
 // no key function, vtable will be generated everywhere it will be used
-// CHECK-TEST10: @_ZTVN6Test101EE = linkonce_odr unnamed_addr constant
+// CHECK-TEST10-DAG: @_ZTVN6Test101EE = linkonce_odr unnamed_addr constant
 struct E : A {};
 
 void g(A& a) {
@@ -365,4 +365,3 @@ void test() {
 }
 }
 
-




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