[AArch64Arm64ECCallLowering] Remove unnecessary bitcasts (NFCI)

These are all pointer bitcasts, which are no longer necessary
with opaque pointers.

Author: nikic

llvm/lib/Target/AArch64/AArch64Arm64ECCallLowering.cpp

@@ -463,7 +463,7 @@ Function *AArch64Arm64ECCallLowering::buildExitThunk(FunctionType *FT,
       IRB.CreateStore(&Arg, Mem);
       if (ArgTranslation == ThunkArgTranslation::Bitcast) {
         Type *IntTy = IRB.getIntNTy(DL.getTypeStoreSizeInBits(Arg.getType()));
-        Args.push_back(IRB.CreateLoad(IntTy, IRB.CreateBitCast(Mem, PtrTy)));
+        Args.push_back(IRB.CreateLoad(IntTy, Mem));
       } else {
         assert(ArgTranslation == ThunkArgTranslation::PointerIndirection);
         Args.push_back(Mem);
@@ -475,7 +475,6 @@ Function *AArch64Arm64ECCallLowering::buildExitThunk(FunctionType *FT,
   }
   // FIXME: Transfer necessary attributes? sret? anything else?
 
-  Callee = IRB.CreateBitCast(Callee, PtrTy);
   CallInst *Call = IRB.CreateCall(X64Ty, Callee, Args);
   Call->setCallingConv(CallingConv::ARM64EC_Thunk_X64);
 
@@ -487,7 +486,7 @@ Function *AArch64Arm64ECCallLowering::buildExitThunk(FunctionType *FT,
       RetVal = IRB.CreateLoad(RetTy, Args[1]);
     } else {
       Value *CastAlloca = IRB.CreateAlloca(RetTy);
-      IRB.CreateStore(Call, IRB.CreateBitCast(CastAlloca, PtrTy));
+      IRB.CreateStore(Call, CastAlloca);
       RetVal = IRB.CreateLoad(RetTy, CastAlloca);
     }
   }
@@ -542,11 +541,11 @@ Function *AArch64Arm64ECCallLowering::buildEntryThunk(Function *F) {
       // Translate array/struct arguments to the expected type.
       if (ArgTranslation == ThunkArgTranslation::Bitcast) {
         Value *CastAlloca = IRB.CreateAlloca(ArgTy);
-        IRB.CreateStore(Arg, IRB.CreateBitCast(CastAlloca, PtrTy));
+        IRB.CreateStore(Arg, CastAlloca);
         Arg = IRB.CreateLoad(ArgTy, CastAlloca);
       } else {
         assert(ArgTranslation == ThunkArgTranslation::PointerIndirection);
-        Arg = IRB.CreateLoad(ArgTy, IRB.CreateBitCast(Arg, PtrTy));
+        Arg = IRB.CreateLoad(ArgTy, Arg);
       }
     }
     assert(Arg->getType() == ArgTy);
@@ -571,7 +570,6 @@ Function *AArch64Arm64ECCallLowering::buildEntryThunk(Function *F) {
 
   // Call the function passed to the thunk.
   Value *Callee = Thunk->getArg(0);
-  Callee = IRB.CreateBitCast(Callee, PtrTy);
   CallInst *Call = IRB.CreateCall(Arm64Ty, Callee, Args);
 
   auto SRetAttr = F->getAttributes().getParamAttr(0, Attribute::StructRet);
@@ -583,10 +581,10 @@ Function *AArch64Arm64ECCallLowering::buildEntryThunk(Function *F) {
 
   Value *RetVal = Call;
   if (TransformDirectToSRet) {
-    IRB.CreateStore(RetVal, IRB.CreateBitCast(Thunk->getArg(1), PtrTy));
+    IRB.CreateStore(RetVal, Thunk->getArg(1));
   } else if (X64RetType != RetTy) {
     Value *CastAlloca = IRB.CreateAlloca(X64RetType);
-    IRB.CreateStore(Call, IRB.CreateBitCast(CastAlloca, PtrTy));
+    IRB.CreateStore(Call, CastAlloca);
     RetVal = IRB.CreateLoad(X64RetType, CastAlloca);
   }
 
@@ -649,15 +647,13 @@ Function *AArch64Arm64ECCallLowering::buildGuestExitThunk(Function *F) {
   // even if the original CallBase is an Invoke or CallBr instruction.
   Function *Thunk = buildExitThunk(F->getFunctionType(), F->getAttributes());
   CallInst *GuardCheck = B.CreateCall(
-      GuardFnType, GuardCheckLoad,
-      {B.CreateBitCast(F, B.getPtrTy()), B.CreateBitCast(Thunk, B.getPtrTy())});
+      GuardFnType, GuardCheckLoad, {F, Thunk});
 
   // Ensure that the first argument is passed in the correct register.
   GuardCheck->setCallingConv(CallingConv::CFGuard_Check);
 
-  Value *GuardRetVal = B.CreateBitCast(GuardCheck, PtrTy);
   SmallVector<Value *> Args(llvm::make_pointer_range(GuestExit->args()));
-  CallInst *Call = B.CreateCall(Arm64Ty, GuardRetVal, Args);
+  CallInst *Call = B.CreateCall(Arm64Ty, GuardCheck, Args);
   Call->setTailCallKind(llvm::CallInst::TCK_MustTail);
 
   if (Call->getType()->isVoidTy())
@@ -712,9 +708,8 @@ AArch64Arm64ECCallLowering::buildPatchableThunk(GlobalAlias *UnmangledAlias,
   // Ensure that the first arguments are passed in the correct registers.
   Dispatch->setCallingConv(CallingConv::CFGuard_Check);
 
-  Value *DispatchRetVal = B.CreateBitCast(Dispatch, PtrTy);
   SmallVector<Value *> Args(llvm::make_pointer_range(GuestExit->args()));
-  CallInst *Call = B.CreateCall(Arm64Ty, DispatchRetVal, Args);
+  CallInst *Call = B.CreateCall(Arm64Ty, Dispatch, Args);
   Call->setTailCallKind(llvm::CallInst::TCK_MustTail);
 
   if (Call->getType()->isVoidTy())
@@ -759,16 +754,13 @@ void AArch64Arm64ECCallLowering::lowerCall(CallBase *CB) {
   // even if the original CallBase is an Invoke or CallBr instruction.
   Function *Thunk = buildExitThunk(CB->getFunctionType(), CB->getAttributes());
   CallInst *GuardCheck =
-      B.CreateCall(GuardFnType, GuardCheckLoad,
-                   {B.CreateBitCast(CalledOperand, B.getPtrTy()),
-                    B.CreateBitCast(Thunk, B.getPtrTy())},
+      B.CreateCall(GuardFnType, GuardCheckLoad, {CalledOperand, Thunk},
                    Bundles);
 
   // Ensure that the first argument is passed in the correct register.
   GuardCheck->setCallingConv(CallingConv::CFGuard_Check);
 
-  Value *GuardRetVal = B.CreateBitCast(GuardCheck, CalledOperand->getType());
-  CB->setCalledOperand(GuardRetVal);
+  CB->setCalledOperand(GuardCheck);
 }
 
 bool AArch64Arm64ECCallLowering::runOnModule(Module &Mod) {
@@ -912,8 +904,7 @@ bool AArch64Arm64ECCallLowering::runOnModule(Module &Mod) {
     SmallVector<Constant *> ThunkMappingArrayElems;
     for (ThunkInfo &Thunk : ThunkMapping) {
       ThunkMappingArrayElems.push_back(ConstantStruct::getAnon(
-          {ConstantExpr::getBitCast(Thunk.Src, PtrTy),
-           ConstantExpr::getBitCast(Thunk.Dst, PtrTy),
+          {Thunk.Src, Thunk.Dst,
            ConstantInt::get(M->getContext(), APInt(32, uint8_t(Thunk.Kind)))}));
     }
     Constant *ThunkMappingArray = ConstantArray::get(