//===-- MSP430ISelLowering.cpp - MSP430 DAG Lowering Implementation ------===// // // 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 MSP430TargetLowering class. // //===----------------------------------------------------------------------===// #include "MSP430ISelLowering.h" #include "MSP430.h" #include "MSP430MachineFunctionInfo.h" #include "MSP430Subtarget.h" #include "MSP430TargetMachine.h" #include "llvm/CodeGen/CallingConvLower.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/SelectionDAGISel.h" #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h" #include "llvm/CodeGen/ValueTypes.h" #include "llvm/IR/CallingConv.h" #include "llvm/IR/DerivedTypes.h" #include "llvm/IR/Function.h" #include "llvm/IR/GlobalAlias.h" #include "llvm/IR/GlobalVariable.h" #include "llvm/IR/Intrinsics.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; #define DEBUG_TYPE "msp430-lower" typedef enum { NoHWMult, HWMultIntr, HWMultNoIntr } HWMultUseMode; static cl::opt HWMultMode("msp430-hwmult-mode", cl::Hidden, cl::desc("Hardware multiplier use mode"), cl::init(HWMultNoIntr), cl::values( clEnumValN(NoHWMult, "no", "Do not use hardware multiplier"), clEnumValN(HWMultIntr, "interrupts", "Assume hardware multiplier can be used inside interrupts"), clEnumValN(HWMultNoIntr, "use", "Assume hardware multiplier cannot be used inside interrupts"), clEnumValEnd)); MSP430TargetLowering::MSP430TargetLowering(const TargetMachine &TM) : TargetLowering(TM, new TargetLoweringObjectFileELF()) { // Set up the register classes. addRegisterClass(MVT::i8, &MSP430::GR8RegClass); addRegisterClass(MVT::i16, &MSP430::GR16RegClass); // Compute derived properties from the register classes computeRegisterProperties(); // Provide all sorts of operation actions // Division is expensive setIntDivIsCheap(false); setStackPointerRegisterToSaveRestore(MSP430::SP); setBooleanContents(ZeroOrOneBooleanContent); setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct? // We have post-incremented loads / stores. setIndexedLoadAction(ISD::POST_INC, MVT::i8, Legal); setIndexedLoadAction(ISD::POST_INC, MVT::i16, Legal); setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::SEXTLOAD, MVT::i8, Expand); setLoadExtAction(ISD::SEXTLOAD, MVT::i16, Expand); // We don't have any truncstores setTruncStoreAction(MVT::i16, MVT::i8, Expand); setOperationAction(ISD::SRA, MVT::i8, Custom); setOperationAction(ISD::SHL, MVT::i8, Custom); setOperationAction(ISD::SRL, MVT::i8, Custom); setOperationAction(ISD::SRA, MVT::i16, Custom); setOperationAction(ISD::SHL, MVT::i16, Custom); setOperationAction(ISD::SRL, MVT::i16, Custom); setOperationAction(ISD::ROTL, MVT::i8, Expand); setOperationAction(ISD::ROTR, MVT::i8, Expand); setOperationAction(ISD::ROTL, MVT::i16, Expand); setOperationAction(ISD::ROTR, MVT::i16, Expand); setOperationAction(ISD::GlobalAddress, MVT::i16, Custom); setOperationAction(ISD::ExternalSymbol, MVT::i16, Custom); setOperationAction(ISD::BlockAddress, MVT::i16, Custom); setOperationAction(ISD::BR_JT, MVT::Other, Expand); setOperationAction(ISD::BR_CC, MVT::i8, Custom); setOperationAction(ISD::BR_CC, MVT::i16, Custom); setOperationAction(ISD::BRCOND, MVT::Other, Expand); setOperationAction(ISD::SETCC, MVT::i8, Custom); setOperationAction(ISD::SETCC, MVT::i16, Custom); setOperationAction(ISD::SELECT, MVT::i8, Expand); setOperationAction(ISD::SELECT, MVT::i16, Expand); setOperationAction(ISD::SELECT_CC, MVT::i8, Custom); setOperationAction(ISD::SELECT_CC, MVT::i16, Custom); setOperationAction(ISD::SIGN_EXTEND, MVT::i16, Custom); setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i8, Expand); setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i16, Expand); setOperationAction(ISD::CTTZ, MVT::i8, Expand); setOperationAction(ISD::CTTZ, MVT::i16, Expand); setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i8, Expand); setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i16, Expand); setOperationAction(ISD::CTLZ, MVT::i8, Expand); setOperationAction(ISD::CTLZ, MVT::i16, Expand); setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i8, Expand); setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i16, Expand); setOperationAction(ISD::CTPOP, MVT::i8, Expand); setOperationAction(ISD::CTPOP, MVT::i16, Expand); setOperationAction(ISD::SHL_PARTS, MVT::i8, Expand); setOperationAction(ISD::SHL_PARTS, MVT::i16, Expand); setOperationAction(ISD::SRL_PARTS, MVT::i8, Expand); setOperationAction(ISD::SRL_PARTS, MVT::i16, Expand); setOperationAction(ISD::SRA_PARTS, MVT::i8, Expand); setOperationAction(ISD::SRA_PARTS, MVT::i16, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand); // FIXME: Implement efficiently multiplication by a constant setOperationAction(ISD::MUL, MVT::i8, Expand); setOperationAction(ISD::MULHS, MVT::i8, Expand); setOperationAction(ISD::MULHU, MVT::i8, Expand); setOperationAction(ISD::SMUL_LOHI, MVT::i8, Expand); setOperationAction(ISD::UMUL_LOHI, MVT::i8, Expand); setOperationAction(ISD::MUL, MVT::i16, Expand); setOperationAction(ISD::MULHS, MVT::i16, Expand); setOperationAction(ISD::MULHU, MVT::i16, Expand); setOperationAction(ISD::SMUL_LOHI, MVT::i16, Expand); setOperationAction(ISD::UMUL_LOHI, MVT::i16, Expand); setOperationAction(ISD::UDIV, MVT::i8, Expand); setOperationAction(ISD::UDIVREM, MVT::i8, Expand); setOperationAction(ISD::UREM, MVT::i8, Expand); setOperationAction(ISD::SDIV, MVT::i8, Expand); setOperationAction(ISD::SDIVREM, MVT::i8, Expand); setOperationAction(ISD::SREM, MVT::i8, Expand); setOperationAction(ISD::UDIV, MVT::i16, Expand); setOperationAction(ISD::UDIVREM, MVT::i16, Expand); setOperationAction(ISD::UREM, MVT::i16, Expand); setOperationAction(ISD::SDIV, MVT::i16, Expand); setOperationAction(ISD::SDIVREM, MVT::i16, Expand); setOperationAction(ISD::SREM, MVT::i16, Expand); // varargs support setOperationAction(ISD::VASTART, MVT::Other, Custom); setOperationAction(ISD::VAARG, MVT::Other, Expand); setOperationAction(ISD::VAEND, MVT::Other, Expand); setOperationAction(ISD::VACOPY, MVT::Other, Expand); setOperationAction(ISD::JumpTable, MVT::i16, Custom); // Libcalls names. if (HWMultMode == HWMultIntr) { setLibcallName(RTLIB::MUL_I8, "__mulqi3hw"); setLibcallName(RTLIB::MUL_I16, "__mulhi3hw"); } else if (HWMultMode == HWMultNoIntr) { setLibcallName(RTLIB::MUL_I8, "__mulqi3hw_noint"); setLibcallName(RTLIB::MUL_I16, "__mulhi3hw_noint"); } setMinFunctionAlignment(1); setPrefFunctionAlignment(2); } SDValue MSP430TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { switch (Op.getOpcode()) { case ISD::SHL: // FALLTHROUGH case ISD::SRL: case ISD::SRA: return LowerShifts(Op, DAG); case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG); case ISD::BlockAddress: return LowerBlockAddress(Op, DAG); case ISD::ExternalSymbol: return LowerExternalSymbol(Op, DAG); case ISD::SETCC: return LowerSETCC(Op, DAG); case ISD::BR_CC: return LowerBR_CC(Op, DAG); case ISD::SELECT_CC: return LowerSELECT_CC(Op, DAG); case ISD::SIGN_EXTEND: return LowerSIGN_EXTEND(Op, DAG); case ISD::RETURNADDR: return LowerRETURNADDR(Op, DAG); case ISD::FRAMEADDR: return LowerFRAMEADDR(Op, DAG); case ISD::VASTART: return LowerVASTART(Op, DAG); case ISD::JumpTable: return LowerJumpTable(Op, DAG); default: llvm_unreachable("unimplemented operand"); } } //===----------------------------------------------------------------------===// // MSP430 Inline Assembly Support //===----------------------------------------------------------------------===// /// getConstraintType - Given a constraint letter, return the type of /// constraint it is for this target. TargetLowering::ConstraintType MSP430TargetLowering::getConstraintType(const std::string &Constraint) const { if (Constraint.size() == 1) { switch (Constraint[0]) { case 'r': return C_RegisterClass; default: break; } } return TargetLowering::getConstraintType(Constraint); } std::pair MSP430TargetLowering:: getRegForInlineAsmConstraint(const std::string &Constraint, MVT VT) const { if (Constraint.size() == 1) { // GCC Constraint Letters switch (Constraint[0]) { default: break; case 'r': // GENERAL_REGS if (VT == MVT::i8) return std::make_pair(0U, &MSP430::GR8RegClass); return std::make_pair(0U, &MSP430::GR16RegClass); } } return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT); } //===----------------------------------------------------------------------===// // Calling Convention Implementation //===----------------------------------------------------------------------===// #include "MSP430GenCallingConv.inc" /// For each argument in a function store the number of pieces it is composed /// of. template static void ParseFunctionArgs(const SmallVectorImpl &Args, SmallVectorImpl &Out) { unsigned CurrentArgIndex = ~0U; for (unsigned i = 0, e = Args.size(); i != e; i++) { if (CurrentArgIndex == Args[i].OrigArgIndex) { Out.back()++; } else { Out.push_back(1); CurrentArgIndex++; } } } static void AnalyzeVarArgs(CCState &State, const SmallVectorImpl &Outs) { State.AnalyzeCallOperands(Outs, CC_MSP430_AssignStack); } static void AnalyzeVarArgs(CCState &State, const SmallVectorImpl &Ins) { State.AnalyzeFormalArguments(Ins, CC_MSP430_AssignStack); } /// Analyze incoming and outgoing function arguments. We need custom C++ code /// to handle special constraints in the ABI like reversing the order of the /// pieces of splitted arguments. In addition, all pieces of a certain argument /// have to be passed either using registers or the stack but never mixing both. template static void AnalyzeArguments(CCState &State, SmallVectorImpl &ArgLocs, const SmallVectorImpl &Args) { static const MCPhysReg RegList[] = { MSP430::R15, MSP430::R14, MSP430::R13, MSP430::R12 }; static const unsigned NbRegs = array_lengthof(RegList); if (State.isVarArg()) { AnalyzeVarArgs(State, Args); return; } SmallVector ArgsParts; ParseFunctionArgs(Args, ArgsParts); unsigned RegsLeft = NbRegs; bool UseStack = false; unsigned ValNo = 0; for (unsigned i = 0, e = ArgsParts.size(); i != e; i++) { MVT ArgVT = Args[ValNo].VT; ISD::ArgFlagsTy ArgFlags = Args[ValNo].Flags; MVT LocVT = ArgVT; CCValAssign::LocInfo LocInfo = CCValAssign::Full; // Promote i8 to i16 if (LocVT == MVT::i8) { LocVT = MVT::i16; if (ArgFlags.isSExt()) LocInfo = CCValAssign::SExt; else if (ArgFlags.isZExt()) LocInfo = CCValAssign::ZExt; else LocInfo = CCValAssign::AExt; } // Handle byval arguments if (ArgFlags.isByVal()) { State.HandleByVal(ValNo++, ArgVT, LocVT, LocInfo, 2, 2, ArgFlags); continue; } unsigned Parts = ArgsParts[i]; if (!UseStack && Parts <= RegsLeft) { unsigned FirstVal = ValNo; for (unsigned j = 0; j < Parts; j++) { unsigned Reg = State.AllocateReg(RegList, NbRegs); State.addLoc(CCValAssign::getReg(ValNo++, ArgVT, Reg, LocVT, LocInfo)); RegsLeft--; } // Reverse the order of the pieces to agree with the "big endian" format // required in the calling convention ABI. SmallVectorImpl::iterator B = ArgLocs.begin() + FirstVal; std::reverse(B, B + Parts); } else { UseStack = true; for (unsigned j = 0; j < Parts; j++) CC_MSP430_AssignStack(ValNo++, ArgVT, LocVT, LocInfo, ArgFlags, State); } } } static void AnalyzeRetResult(CCState &State, const SmallVectorImpl &Ins) { State.AnalyzeCallResult(Ins, RetCC_MSP430); } static void AnalyzeRetResult(CCState &State, const SmallVectorImpl &Outs) { State.AnalyzeReturn(Outs, RetCC_MSP430); } template static void AnalyzeReturnValues(CCState &State, SmallVectorImpl &RVLocs, const SmallVectorImpl &Args) { AnalyzeRetResult(State, Args); // Reverse splitted return values to get the "big endian" format required // to agree with the calling convention ABI. std::reverse(RVLocs.begin(), RVLocs.end()); } SDValue MSP430TargetLowering::LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, SDLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { switch (CallConv) { default: llvm_unreachable("Unsupported calling convention"); case CallingConv::C: case CallingConv::Fast: return LowerCCCArguments(Chain, CallConv, isVarArg, Ins, dl, DAG, InVals); case CallingConv::MSP430_INTR: if (Ins.empty()) return Chain; report_fatal_error("ISRs cannot have arguments"); } } SDValue MSP430TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI, SmallVectorImpl &InVals) const { SelectionDAG &DAG = CLI.DAG; SDLoc &dl = CLI.DL; SmallVectorImpl &Outs = CLI.Outs; SmallVectorImpl &OutVals = CLI.OutVals; SmallVectorImpl &Ins = CLI.Ins; SDValue Chain = CLI.Chain; SDValue Callee = CLI.Callee; bool &isTailCall = CLI.IsTailCall; CallingConv::ID CallConv = CLI.CallConv; bool isVarArg = CLI.IsVarArg; // MSP430 target does not yet support tail call optimization. isTailCall = false; switch (CallConv) { default: llvm_unreachable("Unsupported calling convention"); case CallingConv::Fast: case CallingConv::C: return LowerCCCCallTo(Chain, Callee, CallConv, isVarArg, isTailCall, Outs, OutVals, Ins, dl, DAG, InVals); case CallingConv::MSP430_INTR: report_fatal_error("ISRs cannot be called directly"); } } /// LowerCCCArguments - transform physical registers into virtual registers and /// generate load operations for arguments places on the stack. // FIXME: struct return stuff SDValue MSP430TargetLowering::LowerCCCArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, SDLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); MachineRegisterInfo &RegInfo = MF.getRegInfo(); MSP430MachineFunctionInfo *FuncInfo = MF.getInfo(); // Assign locations to all of the incoming arguments. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext()); AnalyzeArguments(CCInfo, ArgLocs, Ins); // Create frame index for the start of the first vararg value if (isVarArg) { unsigned Offset = CCInfo.getNextStackOffset(); FuncInfo->setVarArgsFrameIndex(MFI->CreateFixedObject(1, Offset, true)); } for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign &VA = ArgLocs[i]; if (VA.isRegLoc()) { // Arguments passed in registers EVT RegVT = VA.getLocVT(); switch (RegVT.getSimpleVT().SimpleTy) { default: { #ifndef NDEBUG errs() << "LowerFormalArguments Unhandled argument type: " << RegVT.getSimpleVT().SimpleTy << "\n"; #endif llvm_unreachable(nullptr); } case MVT::i16: unsigned VReg = RegInfo.createVirtualRegister(&MSP430::GR16RegClass); RegInfo.addLiveIn(VA.getLocReg(), VReg); SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, VReg, RegVT); // If this is an 8-bit value, it is really passed promoted to 16 // bits. Insert an assert[sz]ext to capture this, then truncate to the // right size. if (VA.getLocInfo() == CCValAssign::SExt) ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue, DAG.getValueType(VA.getValVT())); else if (VA.getLocInfo() == CCValAssign::ZExt) ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue, DAG.getValueType(VA.getValVT())); if (VA.getLocInfo() != CCValAssign::Full) ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue); InVals.push_back(ArgValue); } } else { // Sanity check assert(VA.isMemLoc()); SDValue InVal; ISD::ArgFlagsTy Flags = Ins[i].Flags; if (Flags.isByVal()) { int FI = MFI->CreateFixedObject(Flags.getByValSize(), VA.getLocMemOffset(), true); InVal = DAG.getFrameIndex(FI, getPointerTy()); } else { // Load the argument to a virtual register unsigned ObjSize = VA.getLocVT().getSizeInBits()/8; if (ObjSize > 2) { errs() << "LowerFormalArguments Unhandled argument type: " << EVT(VA.getLocVT()).getEVTString() << "\n"; } // 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::i16); InVal = DAG.getLoad(VA.getLocVT(), dl, Chain, FIN, MachinePointerInfo::getFixedStack(FI), false, false, false, 0); } InVals.push_back(InVal); } } return Chain; } SDValue MSP430TargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, SDLoc dl, SelectionDAG &DAG) const { // CCValAssign - represent the assignment of the return value to a location SmallVector RVLocs; // ISRs cannot return any value. if (CallConv == CallingConv::MSP430_INTR && !Outs.empty()) report_fatal_error("ISRs cannot return any value"); // CCState - Info about the registers and stack slot. CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs, *DAG.getContext()); // Analize return values. AnalyzeReturnValues(CCInfo, RVLocs, Outs); SDValue Flag; SmallVector RetOps(1, Chain); // Copy the result values into the output registers. for (unsigned i = 0; i != RVLocs.size(); ++i) { CCValAssign &VA = RVLocs[i]; assert(VA.isRegLoc() && "Can only return in 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())); } unsigned Opc = (CallConv == CallingConv::MSP430_INTR ? MSP430ISD::RETI_FLAG : MSP430ISD::RET_FLAG); RetOps[0] = Chain; // Update chain. // Add the flag if we have it. if (Flag.getNode()) RetOps.push_back(Flag); return DAG.getNode(Opc, dl, MVT::Other, RetOps); } /// LowerCCCCallTo - functions arguments are copied from virtual regs to /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted. // TODO: sret. SDValue MSP430TargetLowering::LowerCCCCallTo(SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, bool isTailCall, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, const SmallVectorImpl &Ins, SDLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // Analyze operands of the call, assigning locations to each operand. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext()); AnalyzeArguments(CCInfo, ArgLocs, Outs); // Get a count of how many bytes are to be pushed on the stack. unsigned NumBytes = CCInfo.getNextStackOffset(); Chain = DAG.getCALLSEQ_START(Chain ,DAG.getConstant(NumBytes, getPointerTy(), true), dl); SmallVector, 4> RegsToPass; SmallVector 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()); if (!StackPtr.getNode()) StackPtr = DAG.getCopyFromReg(Chain, dl, MSP430::SP, getPointerTy()); SDValue PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, DAG.getIntPtrConstant(VA.getLocMemOffset())); SDValue MemOp; ISD::ArgFlagsTy Flags = Outs[i].Flags; if (Flags.isByVal()) { SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), MVT::i16); MemOp = DAG.getMemcpy(Chain, dl, PtrOff, Arg, SizeNode, Flags.getByValAlign(), /*isVolatile*/false, /*AlwaysInline=*/true, MachinePointerInfo(), MachinePointerInfo()); } else { MemOp = DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo(), false, false, 0); } MemOpChains.push_back(MemOp); } } // 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 InFlag; for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, RegsToPass[i].second, InFlag); InFlag = 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. if (GlobalAddressSDNode *G = dyn_cast(Callee)) Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i16); else if (ExternalSymbolSDNode *E = dyn_cast(Callee)) Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i16); // Returns a chain & a flag for retval copy to use. SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); SmallVector Ops; Ops.push_back(Chain); Ops.push_back(Callee); // Add argument registers to the end of the list so that they are // known live into the call. for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) Ops.push_back(DAG.getRegister(RegsToPass[i].first, RegsToPass[i].second.getValueType())); if (InFlag.getNode()) Ops.push_back(InFlag); Chain = DAG.getNode(MSP430ISD::CALL, dl, NodeTys, Ops); InFlag = Chain.getValue(1); // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END(Chain, DAG.getConstant(NumBytes, getPointerTy(), true), DAG.getConstant(0, getPointerTy(), true), InFlag, dl); InFlag = Chain.getValue(1); // Handle result values, copying them out of physregs into vregs that we // return. return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins, dl, DAG, InVals); } /// LowerCallResult - Lower the result values of a call into the /// appropriate copies out of appropriate physical registers. /// SDValue MSP430TargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, SDLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // Assign locations to each value returned by this call. SmallVector RVLocs; CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs, *DAG.getContext()); AnalyzeReturnValues(CCInfo, RVLocs, Ins); // Copy all of the result registers out of their specified physreg. for (unsigned i = 0; i != RVLocs.size(); ++i) { Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(), RVLocs[i].getValVT(), InFlag).getValue(1); InFlag = Chain.getValue(2); InVals.push_back(Chain.getValue(0)); } return Chain; } SDValue MSP430TargetLowering::LowerShifts(SDValue Op, SelectionDAG &DAG) const { unsigned Opc = Op.getOpcode(); SDNode* N = Op.getNode(); EVT VT = Op.getValueType(); SDLoc dl(N); // Expand non-constant shifts to loops: if (!isa(N->getOperand(1))) switch (Opc) { default: llvm_unreachable("Invalid shift opcode!"); case ISD::SHL: return DAG.getNode(MSP430ISD::SHL, dl, VT, N->getOperand(0), N->getOperand(1)); case ISD::SRA: return DAG.getNode(MSP430ISD::SRA, dl, VT, N->getOperand(0), N->getOperand(1)); case ISD::SRL: return DAG.getNode(MSP430ISD::SRL, dl, VT, N->getOperand(0), N->getOperand(1)); } uint64_t ShiftAmount = cast(N->getOperand(1))->getZExtValue(); // Expand the stuff into sequence of shifts. // FIXME: for some shift amounts this might be done better! // E.g.: foo >> (8 + N) => sxt(swpb(foo)) >> N SDValue Victim = N->getOperand(0); if (Opc == ISD::SRL && ShiftAmount) { // Emit a special goodness here: // srl A, 1 => clrc; rrc A Victim = DAG.getNode(MSP430ISD::RRC, dl, VT, Victim); ShiftAmount -= 1; } while (ShiftAmount--) Victim = DAG.getNode((Opc == ISD::SHL ? MSP430ISD::RLA : MSP430ISD::RRA), dl, VT, Victim); return Victim; } SDValue MSP430TargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const { const GlobalValue *GV = cast(Op)->getGlobal(); int64_t Offset = cast(Op)->getOffset(); // Create the TargetGlobalAddress node, folding in the constant offset. SDValue Result = DAG.getTargetGlobalAddress(GV, SDLoc(Op), getPointerTy(), Offset); return DAG.getNode(MSP430ISD::Wrapper, SDLoc(Op), getPointerTy(), Result); } SDValue MSP430TargetLowering::LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const { SDLoc dl(Op); const char *Sym = cast(Op)->getSymbol(); SDValue Result = DAG.getTargetExternalSymbol(Sym, getPointerTy()); return DAG.getNode(MSP430ISD::Wrapper, dl, getPointerTy(), Result); } SDValue MSP430TargetLowering::LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const { SDLoc dl(Op); const BlockAddress *BA = cast(Op)->getBlockAddress(); SDValue Result = DAG.getTargetBlockAddress(BA, getPointerTy()); return DAG.getNode(MSP430ISD::Wrapper, dl, getPointerTy(), Result); } static SDValue EmitCMP(SDValue &LHS, SDValue &RHS, SDValue &TargetCC, ISD::CondCode CC, SDLoc dl, SelectionDAG &DAG) { // FIXME: Handle bittests someday assert(!LHS.getValueType().isFloatingPoint() && "We don't handle FP yet"); // FIXME: Handle jump negative someday MSP430CC::CondCodes TCC = MSP430CC::COND_INVALID; switch (CC) { default: llvm_unreachable("Invalid integer condition!"); case ISD::SETEQ: TCC = MSP430CC::COND_E; // aka COND_Z // Minor optimization: if LHS is a constant, swap operands, then the // constant can be folded into comparison. if (LHS.getOpcode() == ISD::Constant) std::swap(LHS, RHS); break; case ISD::SETNE: TCC = MSP430CC::COND_NE; // aka COND_NZ // Minor optimization: if LHS is a constant, swap operands, then the // constant can be folded into comparison. if (LHS.getOpcode() == ISD::Constant) std::swap(LHS, RHS); break; case ISD::SETULE: std::swap(LHS, RHS); // FALLTHROUGH case ISD::SETUGE: // Turn lhs u>= rhs with lhs constant into rhs u< lhs+1, this allows us to // fold constant into instruction. if (const ConstantSDNode * C = dyn_cast(LHS)) { LHS = RHS; RHS = DAG.getConstant(C->getSExtValue() + 1, C->getValueType(0)); TCC = MSP430CC::COND_LO; break; } TCC = MSP430CC::COND_HS; // aka COND_C break; case ISD::SETUGT: std::swap(LHS, RHS); // FALLTHROUGH case ISD::SETULT: // Turn lhs u< rhs with lhs constant into rhs u>= lhs+1, this allows us to // fold constant into instruction. if (const ConstantSDNode * C = dyn_cast(LHS)) { LHS = RHS; RHS = DAG.getConstant(C->getSExtValue() + 1, C->getValueType(0)); TCC = MSP430CC::COND_HS; break; } TCC = MSP430CC::COND_LO; // aka COND_NC break; case ISD::SETLE: std::swap(LHS, RHS); // FALLTHROUGH case ISD::SETGE: // Turn lhs >= rhs with lhs constant into rhs < lhs+1, this allows us to // fold constant into instruction. if (const ConstantSDNode * C = dyn_cast(LHS)) { LHS = RHS; RHS = DAG.getConstant(C->getSExtValue() + 1, C->getValueType(0)); TCC = MSP430CC::COND_L; break; } TCC = MSP430CC::COND_GE; break; case ISD::SETGT: std::swap(LHS, RHS); // FALLTHROUGH case ISD::SETLT: // Turn lhs < rhs with lhs constant into rhs >= lhs+1, this allows us to // fold constant into instruction. if (const ConstantSDNode * C = dyn_cast(LHS)) { LHS = RHS; RHS = DAG.getConstant(C->getSExtValue() + 1, C->getValueType(0)); TCC = MSP430CC::COND_GE; break; } TCC = MSP430CC::COND_L; break; } TargetCC = DAG.getConstant(TCC, MVT::i8); return DAG.getNode(MSP430ISD::CMP, dl, MVT::Glue, LHS, RHS); } SDValue MSP430TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const { SDValue Chain = Op.getOperand(0); ISD::CondCode CC = cast(Op.getOperand(1))->get(); SDValue LHS = Op.getOperand(2); SDValue RHS = Op.getOperand(3); SDValue Dest = Op.getOperand(4); SDLoc dl (Op); SDValue TargetCC; SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG); return DAG.getNode(MSP430ISD::BR_CC, dl, Op.getValueType(), Chain, Dest, TargetCC, Flag); } SDValue MSP430TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const { SDValue LHS = Op.getOperand(0); SDValue RHS = Op.getOperand(1); SDLoc dl (Op); // If we are doing an AND and testing against zero, then the CMP // will not be generated. The AND (or BIT) will generate the condition codes, // but they are different from CMP. // FIXME: since we're doing a post-processing, use a pseudoinstr here, so // lowering & isel wouldn't diverge. bool andCC = false; if (ConstantSDNode *RHSC = dyn_cast(RHS)) { if (RHSC->isNullValue() && LHS.hasOneUse() && (LHS.getOpcode() == ISD::AND || (LHS.getOpcode() == ISD::TRUNCATE && LHS.getOperand(0).getOpcode() == ISD::AND))) { andCC = true; } } ISD::CondCode CC = cast(Op.getOperand(2))->get(); SDValue TargetCC; SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG); // Get the condition codes directly from the status register, if its easy. // Otherwise a branch will be generated. Note that the AND and BIT // instructions generate different flags than CMP, the carry bit can be used // for NE/EQ. bool Invert = false; bool Shift = false; bool Convert = true; switch (cast(TargetCC)->getZExtValue()) { default: Convert = false; break; case MSP430CC::COND_HS: // Res = SR & 1, no processing is required break; case MSP430CC::COND_LO: // Res = ~(SR & 1) Invert = true; break; case MSP430CC::COND_NE: if (andCC) { // C = ~Z, thus Res = SR & 1, no processing is required } else { // Res = ~((SR >> 1) & 1) Shift = true; Invert = true; } break; case MSP430CC::COND_E: Shift = true; // C = ~Z for AND instruction, thus we can put Res = ~(SR & 1), however, // Res = (SR >> 1) & 1 is 1 word shorter. break; } EVT VT = Op.getValueType(); SDValue One = DAG.getConstant(1, VT); if (Convert) { SDValue SR = DAG.getCopyFromReg(DAG.getEntryNode(), dl, MSP430::SR, MVT::i16, Flag); if (Shift) // FIXME: somewhere this is turned into a SRL, lower it MSP specific? SR = DAG.getNode(ISD::SRA, dl, MVT::i16, SR, One); SR = DAG.getNode(ISD::AND, dl, MVT::i16, SR, One); if (Invert) SR = DAG.getNode(ISD::XOR, dl, MVT::i16, SR, One); return SR; } else { SDValue Zero = DAG.getConstant(0, VT); SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::Glue); SmallVector Ops; Ops.push_back(One); Ops.push_back(Zero); Ops.push_back(TargetCC); Ops.push_back(Flag); return DAG.getNode(MSP430ISD::SELECT_CC, dl, VTs, Ops); } } SDValue MSP430TargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const { SDValue LHS = Op.getOperand(0); SDValue RHS = Op.getOperand(1); SDValue TrueV = Op.getOperand(2); SDValue FalseV = Op.getOperand(3); ISD::CondCode CC = cast(Op.getOperand(4))->get(); SDLoc dl (Op); SDValue TargetCC; SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG); SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::Glue); SmallVector Ops; Ops.push_back(TrueV); Ops.push_back(FalseV); Ops.push_back(TargetCC); Ops.push_back(Flag); return DAG.getNode(MSP430ISD::SELECT_CC, dl, VTs, Ops); } SDValue MSP430TargetLowering::LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG) const { SDValue Val = Op.getOperand(0); EVT VT = Op.getValueType(); SDLoc dl(Op); assert(VT == MVT::i16 && "Only support i16 for now!"); return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, VT, DAG.getNode(ISD::ANY_EXTEND, dl, VT, Val), DAG.getValueType(Val.getValueType())); } SDValue MSP430TargetLowering::getReturnAddressFrameIndex(SelectionDAG &DAG) const { MachineFunction &MF = DAG.getMachineFunction(); MSP430MachineFunctionInfo *FuncInfo = MF.getInfo(); int ReturnAddrIndex = FuncInfo->getRAIndex(); if (ReturnAddrIndex == 0) { // Set up a frame object for the return address. uint64_t SlotSize = getDataLayout()->getPointerSize(); ReturnAddrIndex = MF.getFrameInfo()->CreateFixedObject(SlotSize, -SlotSize, true); FuncInfo->setRAIndex(ReturnAddrIndex); } return DAG.getFrameIndex(ReturnAddrIndex, getPointerTy()); } SDValue MSP430TargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const { MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo(); MFI->setReturnAddressIsTaken(true); if (verifyReturnAddressArgumentIsConstant(Op, DAG)) return SDValue(); unsigned Depth = cast(Op.getOperand(0))->getZExtValue(); SDLoc dl(Op); if (Depth > 0) { SDValue FrameAddr = LowerFRAMEADDR(Op, DAG); SDValue Offset = DAG.getConstant(getDataLayout()->getPointerSize(), MVT::i16); return DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), DAG.getNode(ISD::ADD, dl, getPointerTy(), FrameAddr, Offset), MachinePointerInfo(), false, false, false, 0); } // Just load the return address. SDValue RetAddrFI = getReturnAddressFrameIndex(DAG); return DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(), RetAddrFI, MachinePointerInfo(), false, false, false, 0); } SDValue MSP430TargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const { MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo(); MFI->setFrameAddressIsTaken(true); EVT VT = Op.getValueType(); SDLoc dl(Op); // FIXME probably not meaningful unsigned Depth = cast(Op.getOperand(0))->getZExtValue(); SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, MSP430::FP, VT); while (Depth--) FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr, MachinePointerInfo(), false, false, false, 0); return FrameAddr; } SDValue MSP430TargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG) const { MachineFunction &MF = DAG.getMachineFunction(); MSP430MachineFunctionInfo *FuncInfo = MF.getInfo(); // Frame index of first vararg argument SDValue FrameIndex = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), getPointerTy()); const Value *SV = cast(Op.getOperand(2))->getValue(); // Create a store of the frame index to the location operand return DAG.getStore(Op.getOperand(0), SDLoc(Op), FrameIndex, Op.getOperand(1), MachinePointerInfo(SV), false, false, 0); } SDValue MSP430TargetLowering::LowerJumpTable(SDValue Op, SelectionDAG &DAG) const { JumpTableSDNode *JT = cast(Op); SDValue Result = DAG.getTargetJumpTable(JT->getIndex(), getPointerTy()); return DAG.getNode(MSP430ISD::Wrapper, SDLoc(JT), getPointerTy(), Result); } /// getPostIndexedAddressParts - returns true by value, base pointer and /// offset pointer and addressing mode by reference if this node can be /// combined with a load / store to form a post-indexed load / store. bool MSP430TargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op, SDValue &Base, SDValue &Offset, ISD::MemIndexedMode &AM, SelectionDAG &DAG) const { LoadSDNode *LD = cast(N); if (LD->getExtensionType() != ISD::NON_EXTLOAD) return false; EVT VT = LD->getMemoryVT(); if (VT != MVT::i8 && VT != MVT::i16) return false; if (Op->getOpcode() != ISD::ADD) return false; if (ConstantSDNode *RHS = dyn_cast(Op->getOperand(1))) { uint64_t RHSC = RHS->getZExtValue(); if ((VT == MVT::i16 && RHSC != 2) || (VT == MVT::i8 && RHSC != 1)) return false; Base = Op->getOperand(0); Offset = DAG.getConstant(RHSC, VT); AM = ISD::POST_INC; return true; } return false; } const char *MSP430TargetLowering::getTargetNodeName(unsigned Opcode) const { switch (Opcode) { default: return nullptr; case MSP430ISD::RET_FLAG: return "MSP430ISD::RET_FLAG"; case MSP430ISD::RETI_FLAG: return "MSP430ISD::RETI_FLAG"; case MSP430ISD::RRA: return "MSP430ISD::RRA"; case MSP430ISD::RLA: return "MSP430ISD::RLA"; case MSP430ISD::RRC: return "MSP430ISD::RRC"; case MSP430ISD::CALL: return "MSP430ISD::CALL"; case MSP430ISD::Wrapper: return "MSP430ISD::Wrapper"; case MSP430ISD::BR_CC: return "MSP430ISD::BR_CC"; case MSP430ISD::CMP: return "MSP430ISD::CMP"; case MSP430ISD::SELECT_CC: return "MSP430ISD::SELECT_CC"; case MSP430ISD::SHL: return "MSP430ISD::SHL"; case MSP430ISD::SRA: return "MSP430ISD::SRA"; } } bool MSP430TargetLowering::isTruncateFree(Type *Ty1, Type *Ty2) const { if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy()) return false; return (Ty1->getPrimitiveSizeInBits() > Ty2->getPrimitiveSizeInBits()); } bool MSP430TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const { if (!VT1.isInteger() || !VT2.isInteger()) return false; return (VT1.getSizeInBits() > VT2.getSizeInBits()); } bool MSP430TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const { // MSP430 implicitly zero-extends 8-bit results in 16-bit registers. return 0 && Ty1->isIntegerTy(8) && Ty2->isIntegerTy(16); } bool MSP430TargetLowering::isZExtFree(EVT VT1, EVT VT2) const { // MSP430 implicitly zero-extends 8-bit results in 16-bit registers. return 0 && VT1 == MVT::i8 && VT2 == MVT::i16; } bool MSP430TargetLowering::isZExtFree(SDValue Val, EVT VT2) const { return isZExtFree(Val.getValueType(), VT2); } //===----------------------------------------------------------------------===// // Other Lowering Code //===----------------------------------------------------------------------===// MachineBasicBlock* MSP430TargetLowering::EmitShiftInstr(MachineInstr *MI, MachineBasicBlock *BB) const { MachineFunction *F = BB->getParent(); MachineRegisterInfo &RI = F->getRegInfo(); DebugLoc dl = MI->getDebugLoc(); const TargetInstrInfo &TII = *getTargetMachine().getSubtargetImpl()->getInstrInfo(); unsigned Opc; const TargetRegisterClass * RC; switch (MI->getOpcode()) { default: llvm_unreachable("Invalid shift opcode!"); case MSP430::Shl8: Opc = MSP430::SHL8r1; RC = &MSP430::GR8RegClass; break; case MSP430::Shl16: Opc = MSP430::SHL16r1; RC = &MSP430::GR16RegClass; break; case MSP430::Sra8: Opc = MSP430::SAR8r1; RC = &MSP430::GR8RegClass; break; case MSP430::Sra16: Opc = MSP430::SAR16r1; RC = &MSP430::GR16RegClass; break; case MSP430::Srl8: Opc = MSP430::SAR8r1c; RC = &MSP430::GR8RegClass; break; case MSP430::Srl16: Opc = MSP430::SAR16r1c; RC = &MSP430::GR16RegClass; break; } const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineFunction::iterator I = BB; ++I; // Create loop block MachineBasicBlock *LoopBB = F->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *RemBB = F->CreateMachineBasicBlock(LLVM_BB); F->insert(I, LoopBB); F->insert(I, RemBB); // Update machine-CFG edges by transferring all successors of the current // block to the block containing instructions after shift. RemBB->splice(RemBB->begin(), BB, std::next(MachineBasicBlock::iterator(MI)), BB->end()); RemBB->transferSuccessorsAndUpdatePHIs(BB); // Add adges BB => LoopBB => RemBB, BB => RemBB, LoopBB => LoopBB BB->addSuccessor(LoopBB); BB->addSuccessor(RemBB); LoopBB->addSuccessor(RemBB); LoopBB->addSuccessor(LoopBB); unsigned ShiftAmtReg = RI.createVirtualRegister(&MSP430::GR8RegClass); unsigned ShiftAmtReg2 = RI.createVirtualRegister(&MSP430::GR8RegClass); unsigned ShiftReg = RI.createVirtualRegister(RC); unsigned ShiftReg2 = RI.createVirtualRegister(RC); unsigned ShiftAmtSrcReg = MI->getOperand(2).getReg(); unsigned SrcReg = MI->getOperand(1).getReg(); unsigned DstReg = MI->getOperand(0).getReg(); // BB: // cmp 0, N // je RemBB BuildMI(BB, dl, TII.get(MSP430::CMP8ri)) .addReg(ShiftAmtSrcReg).addImm(0); BuildMI(BB, dl, TII.get(MSP430::JCC)) .addMBB(RemBB) .addImm(MSP430CC::COND_E); // LoopBB: // ShiftReg = phi [%SrcReg, BB], [%ShiftReg2, LoopBB] // ShiftAmt = phi [%N, BB], [%ShiftAmt2, LoopBB] // ShiftReg2 = shift ShiftReg // ShiftAmt2 = ShiftAmt - 1; BuildMI(LoopBB, dl, TII.get(MSP430::PHI), ShiftReg) .addReg(SrcReg).addMBB(BB) .addReg(ShiftReg2).addMBB(LoopBB); BuildMI(LoopBB, dl, TII.get(MSP430::PHI), ShiftAmtReg) .addReg(ShiftAmtSrcReg).addMBB(BB) .addReg(ShiftAmtReg2).addMBB(LoopBB); BuildMI(LoopBB, dl, TII.get(Opc), ShiftReg2) .addReg(ShiftReg); BuildMI(LoopBB, dl, TII.get(MSP430::SUB8ri), ShiftAmtReg2) .addReg(ShiftAmtReg).addImm(1); BuildMI(LoopBB, dl, TII.get(MSP430::JCC)) .addMBB(LoopBB) .addImm(MSP430CC::COND_NE); // RemBB: // DestReg = phi [%SrcReg, BB], [%ShiftReg, LoopBB] BuildMI(*RemBB, RemBB->begin(), dl, TII.get(MSP430::PHI), DstReg) .addReg(SrcReg).addMBB(BB) .addReg(ShiftReg2).addMBB(LoopBB); MI->eraseFromParent(); // The pseudo instruction is gone now. return RemBB; } MachineBasicBlock* MSP430TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *BB) const { unsigned Opc = MI->getOpcode(); if (Opc == MSP430::Shl8 || Opc == MSP430::Shl16 || Opc == MSP430::Sra8 || Opc == MSP430::Sra16 || Opc == MSP430::Srl8 || Opc == MSP430::Srl16) return EmitShiftInstr(MI, BB); const TargetInstrInfo &TII = *getTargetMachine().getSubtargetImpl()->getInstrInfo(); DebugLoc dl = MI->getDebugLoc(); assert((Opc == MSP430::Select16 || Opc == MSP430::Select8) && "Unexpected instr type to insert"); // To "insert" a SELECT instruction, we actually have to insert the diamond // control-flow pattern. The incoming instruction knows the destination vreg // to set, the condition code register to branch on, the true/false values to // select between, and a branch opcode to use. const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineFunction::iterator I = BB; ++I; // thisMBB: // ... // TrueVal = ... // cmpTY ccX, r1, r2 // jCC copy1MBB // fallthrough --> copy0MBB MachineBasicBlock *thisMBB = BB; MachineFunction *F = BB->getParent(); MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *copy1MBB = F->CreateMachineBasicBlock(LLVM_BB); F->insert(I, copy0MBB); F->insert(I, copy1MBB); // Update machine-CFG edges by transferring all successors of the current // block to the new block which will contain the Phi node for the select. copy1MBB->splice(copy1MBB->begin(), BB, std::next(MachineBasicBlock::iterator(MI)), BB->end()); copy1MBB->transferSuccessorsAndUpdatePHIs(BB); // Next, add the true and fallthrough blocks as its successors. BB->addSuccessor(copy0MBB); BB->addSuccessor(copy1MBB); BuildMI(BB, dl, TII.get(MSP430::JCC)) .addMBB(copy1MBB) .addImm(MI->getOperand(3).getImm()); // copy0MBB: // %FalseValue = ... // # fallthrough to copy1MBB BB = copy0MBB; // Update machine-CFG edges BB->addSuccessor(copy1MBB); // copy1MBB: // %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ] // ... BB = copy1MBB; BuildMI(*BB, BB->begin(), dl, TII.get(MSP430::PHI), MI->getOperand(0).getReg()) .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB) .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB); MI->eraseFromParent(); // The pseudo instruction is gone now. return BB; }