|  | //===- ARCISelLowering.cpp - ARC DAG Lowering Impl --------------*- C++ -*-===// | 
|  | // | 
|  | //                     The LLVM Compiler Infrastructure | 
|  | // | 
|  | // This file is distributed under the University of Illinois Open Source | 
|  | // License. See LICENSE.TXT for details. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  | // | 
|  | // This file implements the ARCTargetLowering class. | 
|  | // | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | #include "ARCISelLowering.h" | 
|  | #include "ARC.h" | 
|  | #include "ARCMachineFunctionInfo.h" | 
|  | #include "ARCSubtarget.h" | 
|  | #include "ARCTargetMachine.h" | 
|  | #include "MCTargetDesc/ARCInfo.h" | 
|  | #include "llvm/CodeGen/CallingConvLower.h" | 
|  | #include "llvm/CodeGen/MachineFrameInfo.h" | 
|  | #include "llvm/CodeGen/MachineFunction.h" | 
|  | #include "llvm/CodeGen/MachineInstrBuilder.h" | 
|  | #include "llvm/CodeGen/MachineJumpTableInfo.h" | 
|  | #include "llvm/CodeGen/MachineRegisterInfo.h" | 
|  | #include "llvm/CodeGen/SelectionDAGISel.h" | 
|  | #include "llvm/CodeGen/ValueTypes.h" | 
|  | #include "llvm/IR/CallingConv.h" | 
|  | #include "llvm/IR/Intrinsics.h" | 
|  | #include "llvm/Support/Debug.h" | 
|  | #include <algorithm> | 
|  |  | 
|  | #define DEBUG_TYPE "arc-lower" | 
|  |  | 
|  | using namespace llvm; | 
|  |  | 
|  | static SDValue lowerCallResult(SDValue Chain, SDValue InFlag, | 
|  | const SmallVectorImpl<CCValAssign> &RVLocs, | 
|  | SDLoc dl, SelectionDAG &DAG, | 
|  | SmallVectorImpl<SDValue> &InVals); | 
|  |  | 
|  | static ARCCC::CondCode ISDCCtoARCCC(ISD::CondCode isdCC) { | 
|  | switch (isdCC) { | 
|  | case ISD::SETUEQ: | 
|  | return ARCCC::EQ; | 
|  | case ISD::SETUGT: | 
|  | return ARCCC::HI; | 
|  | case ISD::SETUGE: | 
|  | return ARCCC::HS; | 
|  | case ISD::SETULT: | 
|  | return ARCCC::LO; | 
|  | case ISD::SETULE: | 
|  | return ARCCC::LS; | 
|  | case ISD::SETUNE: | 
|  | return ARCCC::NE; | 
|  | case ISD::SETEQ: | 
|  | return ARCCC::EQ; | 
|  | case ISD::SETGT: | 
|  | return ARCCC::GT; | 
|  | case ISD::SETGE: | 
|  | return ARCCC::GE; | 
|  | case ISD::SETLT: | 
|  | return ARCCC::LT; | 
|  | case ISD::SETLE: | 
|  | return ARCCC::LE; | 
|  | case ISD::SETNE: | 
|  | return ARCCC::NE; | 
|  | default: | 
|  | llvm_unreachable("Unhandled ISDCC code."); | 
|  | } | 
|  | } | 
|  |  | 
|  | ARCTargetLowering::ARCTargetLowering(const TargetMachine &TM, | 
|  | const ARCSubtarget &Subtarget) | 
|  | : TargetLowering(TM), Subtarget(Subtarget) { | 
|  | // Set up the register classes. | 
|  | addRegisterClass(MVT::i32, &ARC::GPR32RegClass); | 
|  |  | 
|  | // Compute derived properties from the register classes | 
|  | computeRegisterProperties(Subtarget.getRegisterInfo()); | 
|  |  | 
|  | setStackPointerRegisterToSaveRestore(ARC::SP); | 
|  |  | 
|  | setSchedulingPreference(Sched::Source); | 
|  |  | 
|  | // Use i32 for setcc operations results (slt, sgt, ...). | 
|  | setBooleanContents(ZeroOrOneBooleanContent); | 
|  | setBooleanVectorContents(ZeroOrOneBooleanContent); | 
|  |  | 
|  | for (unsigned Opc = 0; Opc < ISD::BUILTIN_OP_END; ++Opc) | 
|  | setOperationAction(Opc, MVT::i32, Expand); | 
|  |  | 
|  | // Operations to get us off of the ground. | 
|  | // Basic. | 
|  | setOperationAction(ISD::ADD, MVT::i32, Legal); | 
|  | setOperationAction(ISD::SUB, MVT::i32, Legal); | 
|  | setOperationAction(ISD::AND, MVT::i32, Legal); | 
|  | setOperationAction(ISD::SMAX, MVT::i32, Legal); | 
|  | setOperationAction(ISD::SMIN, MVT::i32, Legal); | 
|  |  | 
|  | // Need barrel shifter. | 
|  | setOperationAction(ISD::SHL, MVT::i32, Legal); | 
|  | setOperationAction(ISD::SRA, MVT::i32, Legal); | 
|  | setOperationAction(ISD::SRL, MVT::i32, Legal); | 
|  | setOperationAction(ISD::ROTR, MVT::i32, Legal); | 
|  |  | 
|  | setOperationAction(ISD::Constant, MVT::i32, Legal); | 
|  | setOperationAction(ISD::UNDEF, MVT::i32, Legal); | 
|  |  | 
|  | // Need multiplier | 
|  | setOperationAction(ISD::MUL, MVT::i32, Legal); | 
|  | setOperationAction(ISD::MULHS, MVT::i32, Legal); | 
|  | setOperationAction(ISD::MULHU, MVT::i32, Legal); | 
|  | setOperationAction(ISD::LOAD, MVT::i32, Legal); | 
|  | setOperationAction(ISD::STORE, MVT::i32, Legal); | 
|  |  | 
|  | setOperationAction(ISD::SELECT_CC, MVT::i32, Custom); | 
|  | setOperationAction(ISD::BR_CC, MVT::i32, Custom); | 
|  | setOperationAction(ISD::BRCOND, MVT::Other, Expand); | 
|  | setOperationAction(ISD::BR_JT, MVT::Other, Expand); | 
|  | setOperationAction(ISD::JumpTable, MVT::i32, Custom); | 
|  |  | 
|  | // Have psuedo instruction for frame addresses. | 
|  | setOperationAction(ISD::FRAMEADDR, MVT::i32, Legal); | 
|  | // Custom lower global addresses. | 
|  | setOperationAction(ISD::GlobalAddress, MVT::i32, Custom); | 
|  |  | 
|  | // Expand var-args ops. | 
|  | setOperationAction(ISD::VASTART, MVT::Other, Custom); | 
|  | setOperationAction(ISD::VAEND, MVT::Other, Expand); | 
|  | setOperationAction(ISD::VAARG, MVT::Other, Expand); | 
|  | setOperationAction(ISD::VACOPY, MVT::Other, Expand); | 
|  |  | 
|  | // Other expansions | 
|  | setOperationAction(ISD::STACKSAVE, MVT::Other, Expand); | 
|  | setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand); | 
|  |  | 
|  | // Sign extend inreg | 
|  | setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Custom); | 
|  | } | 
|  |  | 
|  | const char *ARCTargetLowering::getTargetNodeName(unsigned Opcode) const { | 
|  | switch (Opcode) { | 
|  | case ARCISD::BL: | 
|  | return "ARCISD::BL"; | 
|  | case ARCISD::CMOV: | 
|  | return "ARCISD::CMOV"; | 
|  | case ARCISD::CMP: | 
|  | return "ARCISD::CMP"; | 
|  | case ARCISD::BRcc: | 
|  | return "ARCISD::BRcc"; | 
|  | case ARCISD::RET: | 
|  | return "ARCISD::RET"; | 
|  | case ARCISD::GAWRAPPER: | 
|  | return "ARCISD::GAWRAPPER"; | 
|  | } | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | //  Misc Lower Operation implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const { | 
|  | SDValue LHS = Op.getOperand(0); | 
|  | SDValue RHS = Op.getOperand(1); | 
|  | ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get(); | 
|  | SDValue TVal = Op.getOperand(2); | 
|  | SDValue FVal = Op.getOperand(3); | 
|  | SDLoc dl(Op); | 
|  | ARCCC::CondCode ArcCC = ISDCCtoARCCC(CC); | 
|  | assert(LHS.getValueType() == MVT::i32 && "Only know how to SELECT_CC i32"); | 
|  | SDValue Cmp = DAG.getNode(ARCISD::CMP, dl, MVT::Glue, LHS, RHS); | 
|  | return DAG.getNode(ARCISD::CMOV, dl, TVal.getValueType(), TVal, FVal, | 
|  | DAG.getConstant(ArcCC, dl, MVT::i32), Cmp); | 
|  | } | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op, | 
|  | SelectionDAG &DAG) const { | 
|  | SDValue Op0 = Op.getOperand(0); | 
|  | SDLoc dl(Op); | 
|  | assert(Op.getValueType() == MVT::i32 && | 
|  | "Unhandled target sign_extend_inreg."); | 
|  | // These are legal | 
|  | unsigned Width = cast<VTSDNode>(Op.getOperand(1))->getVT().getSizeInBits(); | 
|  | if (Width == 16 || Width == 8) | 
|  | return Op; | 
|  | if (Width >= 32) { | 
|  | return {}; | 
|  | } | 
|  | SDValue LS = DAG.getNode(ISD::SHL, dl, MVT::i32, Op0, | 
|  | DAG.getConstant(32 - Width, dl, MVT::i32)); | 
|  | SDValue SR = DAG.getNode(ISD::SRA, dl, MVT::i32, LS, | 
|  | DAG.getConstant(32 - Width, dl, MVT::i32)); | 
|  | return SR; | 
|  | } | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const { | 
|  | SDValue Chain = Op.getOperand(0); | 
|  | ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get(); | 
|  | SDValue LHS = Op.getOperand(2); | 
|  | SDValue RHS = Op.getOperand(3); | 
|  | SDValue Dest = Op.getOperand(4); | 
|  | SDLoc dl(Op); | 
|  | ARCCC::CondCode arcCC = ISDCCtoARCCC(CC); | 
|  | assert(LHS.getValueType() == MVT::i32 && "Only know how to BR_CC i32"); | 
|  | return DAG.getNode(ARCISD::BRcc, dl, MVT::Other, Chain, Dest, LHS, RHS, | 
|  | DAG.getConstant(arcCC, dl, MVT::i32)); | 
|  | } | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) const { | 
|  | auto *N = cast<JumpTableSDNode>(Op); | 
|  | SDValue GA = DAG.getTargetJumpTable(N->getIndex(), MVT::i32); | 
|  | return DAG.getNode(ARCISD::GAWRAPPER, SDLoc(N), MVT::i32, GA); | 
|  | } | 
|  |  | 
|  | #include "ARCGenCallingConv.inc" | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | //                  Call Calling Convention Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | /// ARC call implementation | 
|  | SDValue ARCTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, | 
|  | SmallVectorImpl<SDValue> &InVals) const { | 
|  | SelectionDAG &DAG = CLI.DAG; | 
|  | SDLoc &dl = CLI.DL; | 
|  | SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs; | 
|  | SmallVectorImpl<SDValue> &OutVals = CLI.OutVals; | 
|  | SmallVectorImpl<ISD::InputArg> &Ins = CLI.Ins; | 
|  | SDValue Chain = CLI.Chain; | 
|  | SDValue Callee = CLI.Callee; | 
|  | CallingConv::ID CallConv = CLI.CallConv; | 
|  | bool IsVarArg = CLI.IsVarArg; | 
|  | bool &IsTailCall = CLI.IsTailCall; | 
|  |  | 
|  | IsTailCall = false; // Do not support tail calls yet. | 
|  |  | 
|  | SmallVector<CCValAssign, 16> ArgLocs; | 
|  | CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, | 
|  | *DAG.getContext()); | 
|  |  | 
|  | CCInfo.AnalyzeCallOperands(Outs, CC_ARC); | 
|  |  | 
|  | SmallVector<CCValAssign, 16> RVLocs; | 
|  | // Analyze return values to determine the number of bytes of stack required. | 
|  | CCState RetCCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs, | 
|  | *DAG.getContext()); | 
|  | RetCCInfo.AllocateStack(CCInfo.getNextStackOffset(), 4); | 
|  | RetCCInfo.AnalyzeCallResult(Ins, RetCC_ARC); | 
|  |  | 
|  | // Get a count of how many bytes are to be pushed on the stack. | 
|  | unsigned NumBytes = RetCCInfo.getNextStackOffset(); | 
|  | auto PtrVT = getPointerTy(DAG.getDataLayout()); | 
|  |  | 
|  | Chain = DAG.getCALLSEQ_START(Chain, NumBytes, 0, dl); | 
|  |  | 
|  | SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass; | 
|  | SmallVector<SDValue, 12> MemOpChains; | 
|  |  | 
|  | SDValue StackPtr; | 
|  | // Walk the register/memloc assignments, inserting copies/loads. | 
|  | for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { | 
|  | CCValAssign &VA = ArgLocs[i]; | 
|  | SDValue Arg = OutVals[i]; | 
|  |  | 
|  | // Promote the value if needed. | 
|  | switch (VA.getLocInfo()) { | 
|  | default: | 
|  | llvm_unreachable("Unknown loc info!"); | 
|  | case CCValAssign::Full: | 
|  | break; | 
|  | case CCValAssign::SExt: | 
|  | Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg); | 
|  | break; | 
|  | case CCValAssign::ZExt: | 
|  | Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg); | 
|  | break; | 
|  | case CCValAssign::AExt: | 
|  | Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg); | 
|  | break; | 
|  | } | 
|  |  | 
|  | // Arguments that can be passed on register must be kept at | 
|  | // RegsToPass vector | 
|  | if (VA.isRegLoc()) { | 
|  | RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg)); | 
|  | } else { | 
|  | assert(VA.isMemLoc() && "Must be register or memory argument."); | 
|  | if (!StackPtr.getNode()) | 
|  | StackPtr = DAG.getCopyFromReg(Chain, dl, ARC::SP, | 
|  | getPointerTy(DAG.getDataLayout())); | 
|  | // Calculate the stack position. | 
|  | SDValue SOffset = DAG.getIntPtrConstant(VA.getLocMemOffset(), dl); | 
|  | SDValue PtrOff = DAG.getNode( | 
|  | ISD::ADD, dl, getPointerTy(DAG.getDataLayout()), StackPtr, SOffset); | 
|  |  | 
|  | SDValue Store = | 
|  | DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo()); | 
|  | MemOpChains.push_back(Store); | 
|  | IsTailCall = false; | 
|  | } | 
|  | } | 
|  |  | 
|  | // Transform all store nodes into one single node because | 
|  | // all store nodes are independent of each other. | 
|  | if (!MemOpChains.empty()) | 
|  | Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains); | 
|  |  | 
|  | // Build a sequence of copy-to-reg nodes chained together with token | 
|  | // chain and flag operands which copy the outgoing args into registers. | 
|  | // The InFlag in necessary since all emitted instructions must be | 
|  | // stuck together. | 
|  | SDValue Glue; | 
|  | for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { | 
|  | Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, | 
|  | RegsToPass[i].second, Glue); | 
|  | Glue = Chain.getValue(1); | 
|  | } | 
|  |  | 
|  | // If the callee is a GlobalAddress node (quite common, every direct call is) | 
|  | // turn it into a TargetGlobalAddress node so that legalize doesn't hack it. | 
|  | // Likewise ExternalSymbol -> TargetExternalSymbol. | 
|  | bool IsDirect = true; | 
|  | if (auto *G = dyn_cast<GlobalAddressSDNode>(Callee)) | 
|  | Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i32); | 
|  | else if (auto *E = dyn_cast<ExternalSymbolSDNode>(Callee)) | 
|  | Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i32); | 
|  | else | 
|  | IsDirect = false; | 
|  | // Branch + Link = #chain, #target_address, #opt_in_flags... | 
|  | //             = Chain, Callee, Reg#1, Reg#2, ... | 
|  | // | 
|  | // Returns a chain & a flag for retval copy to use. | 
|  | SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); | 
|  | SmallVector<SDValue, 8> Ops; | 
|  | Ops.push_back(Chain); | 
|  | Ops.push_back(Callee); | 
|  |  | 
|  | for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) | 
|  | Ops.push_back(DAG.getRegister(RegsToPass[i].first, | 
|  | RegsToPass[i].second.getValueType())); | 
|  |  | 
|  | // Add a register mask operand representing the call-preserved registers. | 
|  | const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo(); | 
|  | const uint32_t *Mask = | 
|  | TRI->getCallPreservedMask(DAG.getMachineFunction(), CallConv); | 
|  | assert(Mask && "Missing call preserved mask for calling convention"); | 
|  | Ops.push_back(DAG.getRegisterMask(Mask)); | 
|  |  | 
|  | if (Glue.getNode()) | 
|  | Ops.push_back(Glue); | 
|  |  | 
|  | Chain = DAG.getNode(IsDirect ? ARCISD::BL : ARCISD::JL, dl, NodeTys, Ops); | 
|  | Glue = Chain.getValue(1); | 
|  |  | 
|  | // Create the CALLSEQ_END node. | 
|  | Chain = DAG.getCALLSEQ_END(Chain, DAG.getConstant(NumBytes, dl, PtrVT, true), | 
|  | DAG.getConstant(0, dl, PtrVT, true), Glue, dl); | 
|  | Glue = Chain.getValue(1); | 
|  |  | 
|  | // Handle result values, copying them out of physregs into vregs that we | 
|  | // return. | 
|  | if (IsTailCall) | 
|  | return Chain; | 
|  | return lowerCallResult(Chain, Glue, RVLocs, dl, DAG, InVals); | 
|  | } | 
|  |  | 
|  | /// Lower the result values of a call into the appropriate copies out of | 
|  | /// physical registers / memory locations. | 
|  | static SDValue lowerCallResult(SDValue Chain, SDValue Glue, | 
|  | const SmallVectorImpl<CCValAssign> &RVLocs, | 
|  | SDLoc dl, SelectionDAG &DAG, | 
|  | SmallVectorImpl<SDValue> &InVals) { | 
|  | SmallVector<std::pair<int, unsigned>, 4> ResultMemLocs; | 
|  | // Copy results out of physical registers. | 
|  | for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) { | 
|  | const CCValAssign &VA = RVLocs[i]; | 
|  | if (VA.isRegLoc()) { | 
|  | SDValue RetValue; | 
|  | RetValue = | 
|  | DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), VA.getValVT(), Glue); | 
|  | Chain = RetValue.getValue(1); | 
|  | Glue = RetValue.getValue(2); | 
|  | InVals.push_back(RetValue); | 
|  | } else { | 
|  | assert(VA.isMemLoc() && "Must be memory location."); | 
|  | ResultMemLocs.push_back( | 
|  | std::make_pair(VA.getLocMemOffset(), InVals.size())); | 
|  |  | 
|  | // Reserve space for this result. | 
|  | InVals.push_back(SDValue()); | 
|  | } | 
|  | } | 
|  |  | 
|  | // Copy results out of memory. | 
|  | SmallVector<SDValue, 4> MemOpChains; | 
|  | for (unsigned i = 0, e = ResultMemLocs.size(); i != e; ++i) { | 
|  | int Offset = ResultMemLocs[i].first; | 
|  | unsigned Index = ResultMemLocs[i].second; | 
|  | SDValue StackPtr = DAG.getRegister(ARC::SP, MVT::i32); | 
|  | SDValue SpLoc = DAG.getNode(ISD::ADD, dl, MVT::i32, StackPtr, | 
|  | DAG.getConstant(Offset, dl, MVT::i32)); | 
|  | SDValue Load = | 
|  | DAG.getLoad(MVT::i32, dl, Chain, SpLoc, MachinePointerInfo()); | 
|  | InVals[Index] = Load; | 
|  | MemOpChains.push_back(Load.getValue(1)); | 
|  | } | 
|  |  | 
|  | // Transform all loads nodes into one single node because | 
|  | // all load nodes are independent of each other. | 
|  | if (!MemOpChains.empty()) | 
|  | Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains); | 
|  |  | 
|  | return Chain; | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | //             Formal Arguments Calling Convention Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | namespace { | 
|  |  | 
|  | struct ArgDataPair { | 
|  | SDValue SDV; | 
|  | ISD::ArgFlagsTy Flags; | 
|  | }; | 
|  |  | 
|  | } // end anonymous namespace | 
|  |  | 
|  | /// ARC formal arguments implementation | 
|  | SDValue ARCTargetLowering::LowerFormalArguments( | 
|  | SDValue Chain, CallingConv::ID CallConv, bool IsVarArg, | 
|  | const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl, | 
|  | SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const { | 
|  | switch (CallConv) { | 
|  | default: | 
|  | llvm_unreachable("Unsupported calling convention"); | 
|  | case CallingConv::C: | 
|  | case CallingConv::Fast: | 
|  | return LowerCallArguments(Chain, CallConv, IsVarArg, Ins, dl, DAG, InVals); | 
|  | } | 
|  | } | 
|  |  | 
|  | /// Transform physical registers into virtual registers, and generate load | 
|  | /// operations for argument places on the stack. | 
|  | SDValue ARCTargetLowering::LowerCallArguments( | 
|  | SDValue Chain, CallingConv::ID CallConv, bool IsVarArg, | 
|  | const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc dl, SelectionDAG &DAG, | 
|  | SmallVectorImpl<SDValue> &InVals) const { | 
|  | MachineFunction &MF = DAG.getMachineFunction(); | 
|  | MachineFrameInfo &MFI = MF.getFrameInfo(); | 
|  | MachineRegisterInfo &RegInfo = MF.getRegInfo(); | 
|  | auto *AFI = MF.getInfo<ARCFunctionInfo>(); | 
|  |  | 
|  | // Assign locations to all of the incoming arguments. | 
|  | SmallVector<CCValAssign, 16> ArgLocs; | 
|  | CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, | 
|  | *DAG.getContext()); | 
|  |  | 
|  | CCInfo.AnalyzeFormalArguments(Ins, CC_ARC); | 
|  |  | 
|  | unsigned StackSlotSize = 4; | 
|  |  | 
|  | if (!IsVarArg) | 
|  | AFI->setReturnStackOffset(CCInfo.getNextStackOffset()); | 
|  |  | 
|  | // All getCopyFromReg ops must precede any getMemcpys to prevent the | 
|  | // scheduler clobbering a register before it has been copied. | 
|  | // The stages are: | 
|  | // 1. CopyFromReg (and load) arg & vararg registers. | 
|  | // 2. Chain CopyFromReg nodes into a TokenFactor. | 
|  | // 3. Memcpy 'byVal' args & push final InVals. | 
|  | // 4. Chain mem ops nodes into a TokenFactor. | 
|  | SmallVector<SDValue, 4> CFRegNode; | 
|  | SmallVector<ArgDataPair, 4> ArgData; | 
|  | SmallVector<SDValue, 4> MemOps; | 
|  |  | 
|  | // 1a. CopyFromReg (and load) arg registers. | 
|  | for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { | 
|  | CCValAssign &VA = ArgLocs[i]; | 
|  | SDValue ArgIn; | 
|  |  | 
|  | if (VA.isRegLoc()) { | 
|  | // Arguments passed in registers | 
|  | EVT RegVT = VA.getLocVT(); | 
|  | switch (RegVT.getSimpleVT().SimpleTy) { | 
|  | default: { | 
|  | LLVM_DEBUG(errs() << "LowerFormalArguments Unhandled argument type: " | 
|  | << (unsigned)RegVT.getSimpleVT().SimpleTy << "\n"); | 
|  | llvm_unreachable("Unhandled LowerFormalArguments type."); | 
|  | } | 
|  | case MVT::i32: | 
|  | unsigned VReg = RegInfo.createVirtualRegister(&ARC::GPR32RegClass); | 
|  | RegInfo.addLiveIn(VA.getLocReg(), VReg); | 
|  | ArgIn = DAG.getCopyFromReg(Chain, dl, VReg, RegVT); | 
|  | CFRegNode.push_back(ArgIn.getValue(ArgIn->getNumValues() - 1)); | 
|  | } | 
|  | } else { | 
|  | // sanity check | 
|  | assert(VA.isMemLoc()); | 
|  | // Load the argument to a virtual register | 
|  | unsigned ObjSize = VA.getLocVT().getStoreSize(); | 
|  | assert((ObjSize <= StackSlotSize) && "Unhandled argument"); | 
|  |  | 
|  | // Create the frame index object for this incoming parameter... | 
|  | int FI = MFI.CreateFixedObject(ObjSize, VA.getLocMemOffset(), true); | 
|  |  | 
|  | // Create the SelectionDAG nodes corresponding to a load | 
|  | // from this parameter | 
|  | SDValue FIN = DAG.getFrameIndex(FI, MVT::i32); | 
|  | ArgIn = DAG.getLoad(VA.getLocVT(), dl, Chain, FIN, | 
|  | MachinePointerInfo::getFixedStack(MF, FI)); | 
|  | } | 
|  | const ArgDataPair ADP = {ArgIn, Ins[i].Flags}; | 
|  | ArgData.push_back(ADP); | 
|  | } | 
|  |  | 
|  | // 1b. CopyFromReg vararg registers. | 
|  | if (IsVarArg) { | 
|  | // Argument registers | 
|  | static const MCPhysReg ArgRegs[] = {ARC::R0, ARC::R1, ARC::R2, ARC::R3, | 
|  | ARC::R4, ARC::R5, ARC::R6, ARC::R7}; | 
|  | auto *AFI = MF.getInfo<ARCFunctionInfo>(); | 
|  | unsigned FirstVAReg = CCInfo.getFirstUnallocated(ArgRegs); | 
|  | if (FirstVAReg < array_lengthof(ArgRegs)) { | 
|  | int Offset = 0; | 
|  | // Save remaining registers, storing higher register numbers at a higher | 
|  | // address | 
|  | // There are (array_lengthof(ArgRegs) - FirstVAReg) registers which | 
|  | // need to be saved. | 
|  | int VarFI = | 
|  | MFI.CreateFixedObject((array_lengthof(ArgRegs) - FirstVAReg) * 4, | 
|  | CCInfo.getNextStackOffset(), true); | 
|  | AFI->setVarArgsFrameIndex(VarFI); | 
|  | SDValue FIN = DAG.getFrameIndex(VarFI, MVT::i32); | 
|  | for (unsigned i = FirstVAReg; i < array_lengthof(ArgRegs); i++) { | 
|  | // Move argument from phys reg -> virt reg | 
|  | unsigned VReg = RegInfo.createVirtualRegister(&ARC::GPR32RegClass); | 
|  | RegInfo.addLiveIn(ArgRegs[i], VReg); | 
|  | SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32); | 
|  | CFRegNode.push_back(Val.getValue(Val->getNumValues() - 1)); | 
|  | SDValue VAObj = DAG.getNode(ISD::ADD, dl, MVT::i32, FIN, | 
|  | DAG.getConstant(Offset, dl, MVT::i32)); | 
|  | // Move argument from virt reg -> stack | 
|  | SDValue Store = | 
|  | DAG.getStore(Val.getValue(1), dl, Val, VAObj, MachinePointerInfo()); | 
|  | MemOps.push_back(Store); | 
|  | Offset += 4; | 
|  | } | 
|  | } else { | 
|  | llvm_unreachable("Too many var args parameters."); | 
|  | } | 
|  | } | 
|  |  | 
|  | // 2. Chain CopyFromReg nodes into a TokenFactor. | 
|  | if (!CFRegNode.empty()) | 
|  | Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, CFRegNode); | 
|  |  | 
|  | // 3. Memcpy 'byVal' args & push final InVals. | 
|  | // Aggregates passed "byVal" need to be copied by the callee. | 
|  | // The callee will use a pointer to this copy, rather than the original | 
|  | // pointer. | 
|  | for (const auto &ArgDI : ArgData) { | 
|  | if (ArgDI.Flags.isByVal() && ArgDI.Flags.getByValSize()) { | 
|  | unsigned Size = ArgDI.Flags.getByValSize(); | 
|  | unsigned Align = std::max(StackSlotSize, ArgDI.Flags.getByValAlign()); | 
|  | // Create a new object on the stack and copy the pointee into it. | 
|  | int FI = MFI.CreateStackObject(Size, Align, false); | 
|  | SDValue FIN = DAG.getFrameIndex(FI, MVT::i32); | 
|  | InVals.push_back(FIN); | 
|  | MemOps.push_back(DAG.getMemcpy( | 
|  | Chain, dl, FIN, ArgDI.SDV, DAG.getConstant(Size, dl, MVT::i32), Align, | 
|  | false, false, false, MachinePointerInfo(), MachinePointerInfo())); | 
|  | } else { | 
|  | InVals.push_back(ArgDI.SDV); | 
|  | } | 
|  | } | 
|  |  | 
|  | // 4. Chain mem ops nodes into a TokenFactor. | 
|  | if (!MemOps.empty()) { | 
|  | MemOps.push_back(Chain); | 
|  | Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOps); | 
|  | } | 
|  |  | 
|  | return Chain; | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | //               Return Value Calling Convention Implementation | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | bool ARCTargetLowering::CanLowerReturn( | 
|  | CallingConv::ID CallConv, MachineFunction &MF, bool IsVarArg, | 
|  | const SmallVectorImpl<ISD::OutputArg> &Outs, LLVMContext &Context) const { | 
|  | SmallVector<CCValAssign, 16> RVLocs; | 
|  | CCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context); | 
|  | if (!CCInfo.CheckReturn(Outs, RetCC_ARC)) | 
|  | return false; | 
|  | if (CCInfo.getNextStackOffset() != 0 && IsVarArg) | 
|  | return false; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | SDValue | 
|  | ARCTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv, | 
|  | bool IsVarArg, | 
|  | const SmallVectorImpl<ISD::OutputArg> &Outs, | 
|  | const SmallVectorImpl<SDValue> &OutVals, | 
|  | const SDLoc &dl, SelectionDAG &DAG) const { | 
|  | auto *AFI = DAG.getMachineFunction().getInfo<ARCFunctionInfo>(); | 
|  | MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo(); | 
|  |  | 
|  | // CCValAssign - represent the assignment of | 
|  | // the return value to a location | 
|  | SmallVector<CCValAssign, 16> RVLocs; | 
|  |  | 
|  | // CCState - Info about the registers and stack slot. | 
|  | CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs, | 
|  | *DAG.getContext()); | 
|  |  | 
|  | // Analyze return values. | 
|  | if (!IsVarArg) | 
|  | CCInfo.AllocateStack(AFI->getReturnStackOffset(), 4); | 
|  |  | 
|  | CCInfo.AnalyzeReturn(Outs, RetCC_ARC); | 
|  |  | 
|  | SDValue Flag; | 
|  | SmallVector<SDValue, 4> RetOps(1, Chain); | 
|  | SmallVector<SDValue, 4> MemOpChains; | 
|  | // Handle return values that must be copied to memory. | 
|  | for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) { | 
|  | CCValAssign &VA = RVLocs[i]; | 
|  | if (VA.isRegLoc()) | 
|  | continue; | 
|  | assert(VA.isMemLoc()); | 
|  | if (IsVarArg) { | 
|  | report_fatal_error("Can't return value from vararg function in memory"); | 
|  | } | 
|  |  | 
|  | int Offset = VA.getLocMemOffset(); | 
|  | unsigned ObjSize = VA.getLocVT().getStoreSize(); | 
|  | // Create the frame index object for the memory location. | 
|  | int FI = MFI.CreateFixedObject(ObjSize, Offset, false); | 
|  |  | 
|  | // Create a SelectionDAG node corresponding to a store | 
|  | // to this memory location. | 
|  | SDValue FIN = DAG.getFrameIndex(FI, MVT::i32); | 
|  | MemOpChains.push_back(DAG.getStore( | 
|  | Chain, dl, OutVals[i], FIN, | 
|  | MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI))); | 
|  | } | 
|  |  | 
|  | // Transform all store nodes into one single node because | 
|  | // all stores are independent of each other. | 
|  | if (!MemOpChains.empty()) | 
|  | Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains); | 
|  |  | 
|  | // Now handle return values copied to registers. | 
|  | for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) { | 
|  | CCValAssign &VA = RVLocs[i]; | 
|  | if (!VA.isRegLoc()) | 
|  | continue; | 
|  | // Copy the result values into the output registers. | 
|  | Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), OutVals[i], Flag); | 
|  |  | 
|  | // guarantee that all emitted copies are | 
|  | // stuck together, avoiding something bad | 
|  | Flag = Chain.getValue(1); | 
|  | RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT())); | 
|  | } | 
|  |  | 
|  | RetOps[0] = Chain; // Update chain. | 
|  |  | 
|  | // Add the flag if we have it. | 
|  | if (Flag.getNode()) | 
|  | RetOps.push_back(Flag); | 
|  |  | 
|  | // What to do with the RetOps? | 
|  | return DAG.getNode(ARCISD::RET, dl, MVT::Other, RetOps); | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // Target Optimization Hooks | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | SDValue ARCTargetLowering::PerformDAGCombine(SDNode *N, | 
|  | DAGCombinerInfo &DCI) const { | 
|  | return {}; | 
|  | } | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | //  Addressing mode description hooks | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | /// Return true if the addressing mode represented by AM is legal for this | 
|  | /// target, for a load/store of the specified type. | 
|  | bool ARCTargetLowering::isLegalAddressingMode(const DataLayout &DL, | 
|  | const AddrMode &AM, Type *Ty, | 
|  | unsigned AS, | 
|  | Instruction *I) const { | 
|  | return AM.Scale == 0; | 
|  | } | 
|  |  | 
|  | // Don't emit tail calls for the time being. | 
|  | bool ARCTargetLowering::mayBeEmittedAsTailCall(const CallInst *CI) const { | 
|  | return false; | 
|  | } | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const { | 
|  | const ARCRegisterInfo &ARI = *Subtarget.getRegisterInfo(); | 
|  | MachineFunction &MF = DAG.getMachineFunction(); | 
|  | MachineFrameInfo &MFI = MF.getFrameInfo(); | 
|  | MFI.setFrameAddressIsTaken(true); | 
|  |  | 
|  | EVT VT = Op.getValueType(); | 
|  | SDLoc dl(Op); | 
|  | assert(cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0 && | 
|  | "Only support lowering frame addr of current frame."); | 
|  | unsigned FrameReg = ARI.getFrameRegister(MF); | 
|  | return DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT); | 
|  | } | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerGlobalAddress(SDValue Op, | 
|  | SelectionDAG &DAG) const { | 
|  | const GlobalAddressSDNode *GN = cast<GlobalAddressSDNode>(Op); | 
|  | const GlobalValue *GV = GN->getGlobal(); | 
|  | SDLoc dl(GN); | 
|  | int64_t Offset = GN->getOffset(); | 
|  | SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, Offset); | 
|  | return DAG.getNode(ARCISD::GAWRAPPER, dl, MVT::i32, GA); | 
|  | } | 
|  |  | 
|  | static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) { | 
|  | MachineFunction &MF = DAG.getMachineFunction(); | 
|  | auto *FuncInfo = MF.getInfo<ARCFunctionInfo>(); | 
|  |  | 
|  | // vastart just stores the address of the VarArgsFrameIndex slot into the | 
|  | // memory location argument. | 
|  | SDLoc dl(Op); | 
|  | EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout()); | 
|  | SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT); | 
|  | const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue(); | 
|  | return DAG.getStore(Op.getOperand(0), dl, FR, Op.getOperand(1), | 
|  | MachinePointerInfo(SV)); | 
|  | } | 
|  |  | 
|  | SDValue ARCTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { | 
|  | switch (Op.getOpcode()) { | 
|  | case ISD::GlobalAddress: | 
|  | return LowerGlobalAddress(Op, DAG); | 
|  | case ISD::FRAMEADDR: | 
|  | return LowerFRAMEADDR(Op, DAG); | 
|  | case ISD::SELECT_CC: | 
|  | return LowerSELECT_CC(Op, DAG); | 
|  | case ISD::BR_CC: | 
|  | return LowerBR_CC(Op, DAG); | 
|  | case ISD::SIGN_EXTEND_INREG: | 
|  | return LowerSIGN_EXTEND_INREG(Op, DAG); | 
|  | case ISD::JumpTable: | 
|  | return LowerJumpTable(Op, DAG); | 
|  | case ISD::VASTART: | 
|  | return LowerVASTART(Op, DAG); | 
|  | default: | 
|  | llvm_unreachable("unimplemented operand"); | 
|  | } | 
|  | } |