[NFC] Replace uses of Type::getPointerTo

Replace some uses of `Type::getPointerTo` via 2 ways
* Remove entirely if it's only used to support an unnecessary bitcast
  (remove the bitcast as well).
* Replace with `PointerType::get`/`PointerType::getUnqual`

NFC opaque pointer clean-up effort.

Author: JOE1994

clang/lib/CodeGen/CGRecordLayoutBuilder.cpp

@@ -658,9 +658,9 @@ void CGRecordLowering::computeVolatileBitfields() {
 
 void CGRecordLowering::accumulateVPtrs() {
   if (Layout.hasOwnVFPtr())
-    Members.push_back(MemberInfo(CharUnits::Zero(), MemberInfo::VFPtr,
-        llvm::FunctionType::get(getIntNType(32), /*isVarArg=*/true)->
-            getPointerTo()->getPointerTo()));
+    Members.push_back(
+        MemberInfo(CharUnits::Zero(), MemberInfo::VFPtr,
+                   llvm::PointerType::getUnqual(Types.getLLVMContext())));
   if (Layout.hasOwnVBPtr())
     Members.push_back(
         MemberInfo(Layout.getVBPtrOffset(), MemberInfo::VBPtr,

clang/lib/CodeGen/MicrosoftCXXABI.cpp

@@ -1262,8 +1262,6 @@ void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
         Builder.CreateInBoundsGEP(CGF.Int8Ty, Int8This, VBaseOffset);
     // vtorDisp is always the 32-bits before the vbase in the class layout.
     VtorDispPtr = Builder.CreateConstGEP1_32(CGF.Int8Ty, VtorDispPtr, -4);
-    VtorDispPtr = Builder.CreateBitCast(
-        VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr");
 
     Builder.CreateAlignedStore(VtorDispValue, VtorDispPtr,
                                CharUnits::fromQuantity(4));
@@ -1568,14 +1566,9 @@ void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
   if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
     CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
     if (!Adjustment.isZero()) {
-      unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
-      llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
-                 *thisTy = This->getType();
-      This = CGF.Builder.CreateBitCast(This, charPtrTy);
       assert(Adjustment.isPositive());
       This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This,
                                                     -Adjustment.getQuantity());
-      This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted");
     }
   }
   setCXXABIThisValue(CGF, This);
@@ -2511,9 +2504,6 @@ LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
   llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
   llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
 
-  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
-  V = CGF.Builder.CreateBitCast(V, RealVarTy->getPointerTo(AS));
-
   CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
   Address Addr(V, RealVarTy, Alignment);
 
@@ -3226,9 +3216,6 @@ llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
     CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
     const MemberPointerType *MPT) {
   assert(MPT->isMemberDataPointer());
-  unsigned AS = Base.getAddressSpace();
-  llvm::Type *PType =
-      CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
   CGBuilderTy &Builder = CGF.Builder;
   const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
   MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
@@ -3256,16 +3243,9 @@ llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
     Addr = Base.getPointer();
   }
 
-  // Cast to char*.
-  Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
-
   // Apply the offset, which we assume is non-null.
-  Addr = Builder.CreateInBoundsGEP(CGF.Int8Ty, Addr, FieldOffset,
+  return Builder.CreateInBoundsGEP(CGF.Int8Ty, Addr, FieldOffset,
                                    "memptr.offset");
-
-  // Cast the address to the appropriate pointer type, adopting the address
-  // space of the base pointer.
-  return Builder.CreateBitCast(Addr, PType);
 }
 
 llvm::Value *

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

@@ -847,7 +847,8 @@ void CallLowering::insertSRetLoads(MachineIRBuilder &MIRBuilder, Type *RetTy,
 
   unsigned NumValues = SplitVTs.size();
   Align BaseAlign = DL.getPrefTypeAlign(RetTy);
-  Type *RetPtrTy = RetTy->getPointerTo(DL.getAllocaAddrSpace());
+  Type *RetPtrTy =
+      PointerType::get(RetTy->getContext(), DL.getAllocaAddrSpace());
   LLT OffsetLLTy = getLLTForType(*DL.getIndexType(RetPtrTy), DL);
 
   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(MF, FI);

mlir/lib/ExecutionEngine/ExecutionEngine.cpp

@@ -155,9 +155,9 @@ static void packFunctionArguments(Module *module) {
 
     // Given a function `foo(<...>)`, define the interface function
     // `mlir_foo(i8**)`.
-    auto *newType = llvm::FunctionType::get(
-        builder.getVoidTy(), builder.getInt8PtrTy()->getPointerTo(),
-        /*isVarArg=*/false);
+    auto *newType =
+        llvm::FunctionType::get(builder.getVoidTy(), builder.getPtrTy(),
+                                /*isVarArg=*/false);
     auto newName = makePackedFunctionName(func.getName());
     auto funcCst = module->getOrInsertFunction(newName, newType);
     llvm::Function *interfaceFunc = cast<llvm::Function>(funcCst.getCallee());
@@ -179,7 +179,6 @@ static void packFunctionArguments(Module *module) {
       llvm::Value *argPtr =
           builder.CreateLoad(builder.getInt8PtrTy(), argPtrPtr);
       llvm::Type *argTy = arg.getType();
-      argPtr = builder.CreateBitCast(argPtr, argTy->getPointerTo());
       llvm::Value *load = builder.CreateLoad(argTy, argPtr);
       args.push_back(load);
     }