[cfe-commits] r117386 - in /cfe/trunk/lib/CodeGen: CGCXX.cpp CGClass.cpp CGExprCXX.cpp CodeGenFunction.h

[Dan Gohman]

Author: djg
Date: Tue Oct 26 13:44:08 2010
New Revision: 117386

URL: http://llvm.org/viewvc/llvm-project?rev=117386&view=rev
Log:
Factor out the code for emitting code to load vtable pointer members
so that it's done in one place.

Modified:
    cfe/trunk/lib/CodeGen/CGCXX.cpp
    cfe/trunk/lib/CodeGen/CGClass.cpp
    cfe/trunk/lib/CodeGen/CGExprCXX.cpp
    cfe/trunk/lib/CodeGen/CodeGenFunction.h

Modified: cfe/trunk/lib/CodeGen/CGCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXX.cpp?rev=117386&r1=117385&r2=117386&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCXX.cpp Tue Oct 26 13:44:08 2010
@@ -289,11 +289,9 @@
 
 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);

Modified: cfe/trunk/lib/CodeGen/CGClass.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGClass.cpp?rev=117386&r1=117385&r2=117386&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGClass.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGClass.cpp Tue Oct 26 13:44:08 2010
@@ -1237,10 +1237,7 @@
   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 @@
                            /*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");
+}

Modified: cfe/trunk/lib/CodeGen/CGExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprCXX.cpp?rev=117386&r1=117385&r2=117386&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprCXX.cpp Tue Oct 26 13:44:08 2010
@@ -1348,8 +1348,6 @@
       // 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::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 @@
         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 @@
   // 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));

Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=117386&r1=117385&r2=117386&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Tue Oct 26 13:44:08 2010
@@ -888,6 +888,9 @@
 
   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