Factor out the code for emitting code to load vtable pointer members

so that it's done in one place.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117386 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index 02cd8f89a2adb5014291908e85f52357d19f0a78..15d1469ffc507f04ff52aec83cae9aaf45591e1e 100644 (file)
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -289,11 +289,9 @@ CodeGenModule::GetAddrOfCXXDestructor(const CXXDestructorDecl *D,
 
 static llvm::Value *BuildVirtualCall(CodeGenFunction &CGF, uint64_t VTableIndex, 
                                      llvm::Value *This, const llvm::Type *Ty) {
-  Ty = Ty->getPointerTo()->getPointerTo()->getPointerTo();
-  
-  llvm::Value *VTable = CGF.Builder.CreateBitCast(This, Ty);
-  VTable = CGF.Builder.CreateLoad(VTable);
+  Ty = Ty->getPointerTo()->getPointerTo();
   
+  llvm::Value *VTable = CGF.GetVTablePtr(This, Ty);
   llvm::Value *VFuncPtr = 
     CGF.Builder.CreateConstInBoundsGEP1_64(VTable, VTableIndex, "vfn");
   return CGF.Builder.CreateLoad(VFuncPtr);

diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 33d1f6e206b7b8273f50dc8d65a5a826efbe3036..ebc84423531c7f0f265b2977b540d1d7ae48448e 100644 (file)
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -1237,10 +1237,7 @@ CodeGenFunction::GetVirtualBaseClassOffset(llvm::Value *This,
   const llvm::Type *Int8PtrTy = 
     llvm::Type::getInt8Ty(VMContext)->getPointerTo();
 
-  llvm::Value *VTablePtr = Builder.CreateBitCast(This, 
-                                                 Int8PtrTy->getPointerTo());
-  VTablePtr = Builder.CreateLoad(VTablePtr, "vtable");
-
+  llvm::Value *VTablePtr = GetVTablePtr(This, Int8PtrTy);
   int64_t VBaseOffsetOffset = 
     CGM.getVTables().getVirtualBaseOffsetOffset(ClassDecl, BaseClassDecl);
   
@@ -1393,3 +1390,9 @@ void CodeGenFunction::InitializeVTablePointers(const CXXRecordDecl *RD) {
                            /*BaseIsNonVirtualPrimaryBase=*/false, 
                            VTable, RD, VBases);
 }
+
+llvm::Value *CodeGenFunction::GetVTablePtr(llvm::Value *This,
+                                           const llvm::Type *Ty) {
+  llvm::Value *VTablePtrSrc = Builder.CreateBitCast(This, Ty->getPointerTo());
+  return Builder.CreateLoad(VTablePtrSrc, "vtable");
+}

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 2a88d339978a881c0180547c8e2e2391411ab259..750e609c855620b7db4761eb2f331993062e6aad 100644 (file)
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -1348,8 +1348,6 @@ llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
       // FIXME: if subE is an lvalue do
       LValue Obj = EmitLValue(subE);
       llvm::Value *This = Obj.getAddress();
-      LTy = LTy->getPointerTo()->getPointerTo();
-      llvm::Value *V = Builder.CreateBitCast(This, LTy);
       // We need to do a zero check for *p, unless it has NonNullAttr.
       // FIXME: PointerType->hasAttr<NonNullAttr>()
       bool CanBeZero = false;
@@ -1360,8 +1358,8 @@ llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
         llvm::BasicBlock *NonZeroBlock = createBasicBlock();
         llvm::BasicBlock *ZeroBlock = createBasicBlock();
         
-        llvm::Value *Zero = llvm::Constant::getNullValue(LTy);
-        Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
+        llvm::Value *Zero = llvm::Constant::getNullValue(This->getType());
+        Builder.CreateCondBr(Builder.CreateICmpNE(This, Zero),
                              NonZeroBlock, ZeroBlock);
         EmitBlock(ZeroBlock);
         /// Call __cxa_bad_typeid
@@ -1373,7 +1371,7 @@ llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
         Builder.CreateUnreachable();
         EmitBlock(NonZeroBlock);
       }
-      V = Builder.CreateLoad(V, "vtable");
+      llvm::Value *V = GetVTablePtr(This, LTy->getPointerTo());
       V = Builder.CreateConstInBoundsGEP1_64(V, -1ULL);
       V = Builder.CreateLoad(V);
       return V;
@@ -1430,8 +1428,7 @@ llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V,
   // See if this is a dynamic_cast(void*)
   if (ToVoid) {
     llvm::Value *This = V;
-    V = Builder.CreateBitCast(This, PtrDiffTy->getPointerTo()->getPointerTo());
-    V = Builder.CreateLoad(V, "vtable");
+    V = GetVTablePtr(This, PtrDiffTy->getPointerTo());
     V = Builder.CreateConstInBoundsGEP1_64(V, -2ULL);
     V = Builder.CreateLoad(V, "offset to top");
     This = Builder.CreateBitCast(This, llvm::Type::getInt8PtrTy(VMContext));

diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index e02cedd944a5477d00b7af6f7a6005469504d540..53056bc609803eb14b76721055b4dc662df85d5c 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -888,6 +888,9 @@ public:
 
   void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
 
+  /// GetVTablePtr - Return the Value of the vtable pointer member pointed
+  /// to by This.
+  llvm::Value *GetVTablePtr(llvm::Value *This, const llvm::Type *Ty);
 
   /// EnterDtorCleanups - Enter the cleanups necessary to complete the
   /// given phase of destruction for a destructor.  The end result