+
+//===----------------------------------------------------------------------===//
+// Implementation of Emulated TLS Model
+//===----------------------------------------------------------------------===//
+
+SDValue TargetLowering::LowerToTLSEmulatedModel(const GlobalAddressSDNode *GA,
+ SelectionDAG &DAG) const {
+ // Access to address of TLS varialbe xyz is lowered to a function call:
+ // __emutls_get_address( address of global variable named "__emutls_v.xyz" )
+ EVT PtrVT = getPointerTy(DAG.getDataLayout());
+ PointerType *VoidPtrType = Type::getInt8PtrTy(*DAG.getContext());
+ SDLoc dl(GA);
+
+ ArgListTy Args;
+ ArgListEntry Entry;
+ std::string NameString = ("__emutls_v." + GA->getGlobal()->getName()).str();
+ Module *VariableModule = const_cast<Module*>(GA->getGlobal()->getParent());
+ StringRef EmuTlsVarName(NameString);
+ GlobalVariable *EmuTlsVar = VariableModule->getNamedGlobal(EmuTlsVarName);
+ if (!EmuTlsVar)
+ EmuTlsVar = dyn_cast_or_null<GlobalVariable>(
+ VariableModule->getOrInsertGlobal(EmuTlsVarName, VoidPtrType));
+ Entry.Node = DAG.getGlobalAddress(EmuTlsVar, dl, PtrVT);
+ Entry.Ty = VoidPtrType;
+ Args.push_back(Entry);
+
+ SDValue EmuTlsGetAddr = DAG.getExternalSymbol("__emutls_get_address", PtrVT);
+
+ TargetLowering::CallLoweringInfo CLI(DAG);
+ CLI.setDebugLoc(dl).setChain(DAG.getEntryNode());
+ CLI.setCallee(CallingConv::C, VoidPtrType, EmuTlsGetAddr, std::move(Args), 0);
+ std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
+
+ // TLSADDR will be codegen'ed as call. Inform MFI that function has calls.
+ // At last for X86 targets, maybe good for other targets too?
+ MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
+ MFI->setAdjustsStack(true); // Is this only for X86 target?
+ MFI->setHasCalls(true);
+
+ assert((GA->getOffset() == 0) &&
+ "Emulated TLS must have zero offset in GlobalAddressSDNode");
+ return CallResult.first;
+}