//===-- MipsISelLowering.cpp - Mips 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 defines the interfaces that Mips uses to lower LLVM code into a // selection DAG. // //===----------------------------------------------------------------------===// #define DEBUG_TYPE "mips-lower" #include "MipsISelLowering.h" #include "MipsMachineFunction.h" #include "MipsTargetMachine.h" #include "MipsTargetObjectFile.h" #include "MipsSubtarget.h" #include "llvm/DerivedTypes.h" #include "llvm/Function.h" #include "llvm/GlobalVariable.h" #include "llvm/Intrinsics.h" #include "llvm/CallingConv.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/ValueTypes.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" using namespace llvm; const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const { switch (Opcode) { case MipsISD::JmpLink : return "MipsISD::JmpLink"; case MipsISD::Hi : return "MipsISD::Hi"; case MipsISD::Lo : return "MipsISD::Lo"; case MipsISD::GPRel : return "MipsISD::GPRel"; case MipsISD::Ret : return "MipsISD::Ret"; case MipsISD::SelectCC : return "MipsISD::SelectCC"; case MipsISD::FPSelectCC : return "MipsISD::FPSelectCC"; case MipsISD::FPBrcond : return "MipsISD::FPBrcond"; case MipsISD::FPCmp : return "MipsISD::FPCmp"; case MipsISD::FPRound : return "MipsISD::FPRound"; default : return NULL; } } MipsTargetLowering:: MipsTargetLowering(MipsTargetMachine &TM) : TargetLowering(TM, new MipsTargetObjectFile()) { Subtarget = &TM.getSubtarget(); // Mips does not have i1 type, so use i32 for // setcc operations results (slt, sgt, ...). setBooleanContents(ZeroOrOneBooleanContent); // Set up the register classes addRegisterClass(MVT::i32, Mips::CPURegsRegisterClass); addRegisterClass(MVT::f32, Mips::FGR32RegisterClass); // When dealing with single precision only, use libcalls if (!Subtarget->isSingleFloat()) if (!Subtarget->isFP64bit()) addRegisterClass(MVT::f64, Mips::AFGR64RegisterClass); // Load extented operations for i1 types must be promoted setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote); setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote); // MIPS doesn't have extending float->double load/store setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand); setTruncStoreAction(MVT::f64, MVT::f32, Expand); // Used by legalize types to correctly generate the setcc result. // Without this, every float setcc comes with a AND/OR with the result, // we don't want this, since the fpcmp result goes to a flag register, // which is used implicitly by brcond and select operations. AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32); // Mips Custom Operations setOperationAction(ISD::GlobalAddress, MVT::i32, Custom); setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom); setOperationAction(ISD::JumpTable, MVT::i32, Custom); setOperationAction(ISD::ConstantPool, MVT::i32, Custom); setOperationAction(ISD::SELECT, MVT::f32, Custom); setOperationAction(ISD::SELECT, MVT::f64, Custom); setOperationAction(ISD::SELECT, MVT::i32, Custom); setOperationAction(ISD::SETCC, MVT::f32, Custom); setOperationAction(ISD::SETCC, MVT::f64, Custom); setOperationAction(ISD::BRCOND, MVT::Other, Custom); setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom); setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom); setOperationAction(ISD::VASTART, MVT::Other, Custom); // We custom lower AND/OR to handle the case where the DAG contain 'ands/ors' // with operands comming from setcc fp comparions. This is necessary since // the result from these setcc are in a flag registers (FCR31). setOperationAction(ISD::AND, MVT::i32, Custom); setOperationAction(ISD::OR, MVT::i32, Custom); // Operations not directly supported by Mips. setOperationAction(ISD::BR_JT, MVT::Other, Expand); setOperationAction(ISD::BR_CC, MVT::Other, Expand); setOperationAction(ISD::SELECT_CC, MVT::Other, Expand); setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand); setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand); setOperationAction(ISD::CTPOP, MVT::i32, Expand); setOperationAction(ISD::CTTZ, MVT::i32, Expand); setOperationAction(ISD::ROTL, MVT::i32, Expand); if (!Subtarget->isMips32r2()) setOperationAction(ISD::ROTR, MVT::i32, Expand); setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand); setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand); setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand); setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand); setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand); setOperationAction(ISD::FSIN, MVT::f32, Expand); setOperationAction(ISD::FCOS, MVT::f32, Expand); setOperationAction(ISD::FPOWI, MVT::f32, Expand); setOperationAction(ISD::FPOW, MVT::f32, Expand); setOperationAction(ISD::FLOG, MVT::f32, Expand); setOperationAction(ISD::FLOG2, MVT::f32, Expand); setOperationAction(ISD::FLOG10, MVT::f32, Expand); setOperationAction(ISD::FEXP, MVT::f32, Expand); setOperationAction(ISD::EH_LABEL, MVT::Other, Expand); // Use the default for now setOperationAction(ISD::STACKSAVE, MVT::Other, Expand); setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand); setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand); if (Subtarget->isSingleFloat()) setOperationAction(ISD::SELECT_CC, MVT::f64, Expand); if (!Subtarget->hasSEInReg()) { setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand); } if (!Subtarget->hasBitCount()) setOperationAction(ISD::CTLZ, MVT::i32, Expand); if (!Subtarget->hasSwap()) setOperationAction(ISD::BSWAP, MVT::i32, Expand); setStackPointerRegisterToSaveRestore(Mips::SP); computeRegisterProperties(); } MVT::SimpleValueType MipsTargetLowering::getSetCCResultType(EVT VT) const { return MVT::i32; } /// getFunctionAlignment - Return the Log2 alignment of this function. unsigned MipsTargetLowering::getFunctionAlignment(const Function *) const { return 2; } SDValue MipsTargetLowering:: LowerOperation(SDValue Op, SelectionDAG &DAG) const { switch (Op.getOpcode()) { case ISD::AND: return LowerANDOR(Op, DAG); case ISD::BRCOND: return LowerBRCOND(Op, DAG); case ISD::ConstantPool: return LowerConstantPool(Op, DAG); case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG); case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG); case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG); case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG); case ISD::JumpTable: return LowerJumpTable(Op, DAG); case ISD::OR: return LowerANDOR(Op, DAG); case ISD::SELECT: return LowerSELECT(Op, DAG); case ISD::SETCC: return LowerSETCC(Op, DAG); case ISD::VASTART: return LowerVASTART(Op, DAG); } return SDValue(); } //===----------------------------------------------------------------------===// // Lower helper functions //===----------------------------------------------------------------------===// // AddLiveIn - This helper function adds the specified physical register to the // MachineFunction as a live in value. It also creates a corresponding // virtual register for it. static unsigned AddLiveIn(MachineFunction &MF, unsigned PReg, TargetRegisterClass *RC) { assert(RC->contains(PReg) && "Not the correct regclass!"); unsigned VReg = MF.getRegInfo().createVirtualRegister(RC); MF.getRegInfo().addLiveIn(PReg, VReg); return VReg; } // Get fp branch code (not opcode) from condition code. static Mips::FPBranchCode GetFPBranchCodeFromCond(Mips::CondCode CC) { if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT) return Mips::BRANCH_T; if (CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) return Mips::BRANCH_F; return Mips::BRANCH_INVALID; } static unsigned FPBranchCodeToOpc(Mips::FPBranchCode BC) { switch(BC) { default: llvm_unreachable("Unknown branch code"); case Mips::BRANCH_T : return Mips::BC1T; case Mips::BRANCH_F : return Mips::BC1F; case Mips::BRANCH_TL : return Mips::BC1TL; case Mips::BRANCH_FL : return Mips::BC1FL; } } static Mips::CondCode FPCondCCodeToFCC(ISD::CondCode CC) { switch (CC) { default: llvm_unreachable("Unknown fp condition code!"); case ISD::SETEQ: case ISD::SETOEQ: return Mips::FCOND_EQ; case ISD::SETUNE: return Mips::FCOND_OGL; case ISD::SETLT: case ISD::SETOLT: return Mips::FCOND_OLT; case ISD::SETGT: case ISD::SETOGT: return Mips::FCOND_OGT; case ISD::SETLE: case ISD::SETOLE: return Mips::FCOND_OLE; case ISD::SETGE: case ISD::SETOGE: return Mips::FCOND_OGE; case ISD::SETULT: return Mips::FCOND_ULT; case ISD::SETULE: return Mips::FCOND_ULE; case ISD::SETUGT: return Mips::FCOND_UGT; case ISD::SETUGE: return Mips::FCOND_UGE; case ISD::SETUO: return Mips::FCOND_UN; case ISD::SETO: return Mips::FCOND_OR; case ISD::SETNE: case ISD::SETONE: return Mips::FCOND_NEQ; case ISD::SETUEQ: return Mips::FCOND_UEQ; } } MachineBasicBlock * MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *BB) const { const TargetInstrInfo *TII = getTargetMachine().getInstrInfo(); bool isFPCmp = false; DebugLoc dl = MI->getDebugLoc(); switch (MI->getOpcode()) { default: assert(false && "Unexpected instr type to insert"); case Mips::Select_FCC: case Mips::Select_FCC_S32: case Mips::Select_FCC_D32: isFPCmp = true; // FALL THROUGH case Mips::Select_CC: case Mips::Select_CC_S32: case Mips::Select_CC_D32: { // To "insert" a SELECT_CC 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 It = BB; ++It; // thisMBB: // ... // TrueVal = ... // setcc r1, r2, r3 // bNE r1, r0, copy1MBB // fallthrough --> copy0MBB MachineBasicBlock *thisMBB = BB; MachineFunction *F = BB->getParent(); MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB); F->insert(It, copy0MBB); F->insert(It, sinkMBB); // Transfer the remainder of BB and its successor edges to sinkMBB. sinkMBB->splice(sinkMBB->begin(), BB, llvm::next(MachineBasicBlock::iterator(MI)), BB->end()); sinkMBB->transferSuccessorsAndUpdatePHIs(BB); // Next, add the true and fallthrough blocks as its successors. BB->addSuccessor(copy0MBB); BB->addSuccessor(sinkMBB); // Emit the right instruction according to the type of the operands compared if (isFPCmp) { // Find the condiction code present in the setcc operation. Mips::CondCode CC = (Mips::CondCode)MI->getOperand(4).getImm(); // Get the branch opcode from the branch code. unsigned Opc = FPBranchCodeToOpc(GetFPBranchCodeFromCond(CC)); BuildMI(BB, dl, TII->get(Opc)).addMBB(sinkMBB); } else BuildMI(BB, dl, TII->get(Mips::BNE)).addReg(MI->getOperand(1).getReg()) .addReg(Mips::ZERO).addMBB(sinkMBB); // copy0MBB: // %FalseValue = ... // # fallthrough to sinkMBB BB = copy0MBB; // Update machine-CFG edges BB->addSuccessor(sinkMBB); // sinkMBB: // %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ] // ... BB = sinkMBB; BuildMI(*BB, BB->begin(), dl, TII->get(Mips::PHI), MI->getOperand(0).getReg()) .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB) .addReg(MI->getOperand(3).getReg()).addMBB(copy0MBB); MI->eraseFromParent(); // The pseudo instruction is gone now. return BB; } } } //===----------------------------------------------------------------------===// // Misc Lower Operation implementation //===----------------------------------------------------------------------===// SDValue MipsTargetLowering:: LowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const { if (!Subtarget->isMips1()) return Op; MachineFunction &MF = DAG.getMachineFunction(); unsigned CCReg = AddLiveIn(MF, Mips::FCR31, Mips::CCRRegisterClass); SDValue Chain = DAG.getEntryNode(); DebugLoc dl = Op.getDebugLoc(); SDValue Src = Op.getOperand(0); // Set the condition register SDValue CondReg = DAG.getCopyFromReg(Chain, dl, CCReg, MVT::i32); CondReg = DAG.getCopyToReg(Chain, dl, Mips::AT, CondReg); CondReg = DAG.getCopyFromReg(CondReg, dl, Mips::AT, MVT::i32); SDValue Cst = DAG.getConstant(3, MVT::i32); SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i32, CondReg, Cst); Cst = DAG.getConstant(2, MVT::i32); SDValue Xor = DAG.getNode(ISD::XOR, dl, MVT::i32, Or, Cst); SDValue InFlag(0, 0); CondReg = DAG.getCopyToReg(Chain, dl, Mips::FCR31, Xor, InFlag); // Emit the round instruction and bit convert to integer SDValue Trunc = DAG.getNode(MipsISD::FPRound, dl, MVT::f32, Src, CondReg.getValue(1)); SDValue BitCvt = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Trunc); return BitCvt; } SDValue MipsTargetLowering:: LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const { SDValue Chain = Op.getOperand(0); SDValue Size = Op.getOperand(1); DebugLoc dl = Op.getDebugLoc(); // Get a reference from Mips stack pointer SDValue StackPointer = DAG.getCopyFromReg(Chain, dl, Mips::SP, MVT::i32); // Subtract the dynamic size from the actual stack size to // obtain the new stack size. SDValue Sub = DAG.getNode(ISD::SUB, dl, MVT::i32, StackPointer, Size); // The Sub result contains the new stack start address, so it // must be placed in the stack pointer register. Chain = DAG.getCopyToReg(StackPointer.getValue(1), dl, Mips::SP, Sub); // This node always has two return values: a new stack pointer // value and a chain SDValue Ops[2] = { Sub, Chain }; return DAG.getMergeValues(Ops, 2, dl); } SDValue MipsTargetLowering:: LowerANDOR(SDValue Op, SelectionDAG &DAG) const { SDValue LHS = Op.getOperand(0); SDValue RHS = Op.getOperand(1); DebugLoc dl = Op.getDebugLoc(); if (LHS.getOpcode() != MipsISD::FPCmp || RHS.getOpcode() != MipsISD::FPCmp) return Op; SDValue True = DAG.getConstant(1, MVT::i32); SDValue False = DAG.getConstant(0, MVT::i32); SDValue LSEL = DAG.getNode(MipsISD::FPSelectCC, dl, True.getValueType(), LHS, True, False, LHS.getOperand(2)); SDValue RSEL = DAG.getNode(MipsISD::FPSelectCC, dl, True.getValueType(), RHS, True, False, RHS.getOperand(2)); return DAG.getNode(Op.getOpcode(), dl, MVT::i32, LSEL, RSEL); } SDValue MipsTargetLowering:: LowerBRCOND(SDValue Op, SelectionDAG &DAG) const { // The first operand is the chain, the second is the condition, the third is // the block to branch to if the condition is true. SDValue Chain = Op.getOperand(0); SDValue Dest = Op.getOperand(2); DebugLoc dl = Op.getDebugLoc(); if (Op.getOperand(1).getOpcode() != MipsISD::FPCmp) return Op; SDValue CondRes = Op.getOperand(1); SDValue CCNode = CondRes.getOperand(2); Mips::CondCode CC = (Mips::CondCode)cast(CCNode)->getZExtValue(); SDValue BrCode = DAG.getConstant(GetFPBranchCodeFromCond(CC), MVT::i32); return DAG.getNode(MipsISD::FPBrcond, dl, Op.getValueType(), Chain, BrCode, Dest, CondRes); } SDValue MipsTargetLowering:: LowerSETCC(SDValue Op, SelectionDAG &DAG) const { // The operands to this are the left and right operands to compare (ops #0, // and #1) and the condition code to compare them with (op #2) as a // CondCodeSDNode. SDValue LHS = Op.getOperand(0); SDValue RHS = Op.getOperand(1); DebugLoc dl = Op.getDebugLoc(); ISD::CondCode CC = cast(Op.getOperand(2))->get(); return DAG.getNode(MipsISD::FPCmp, dl, Op.getValueType(), LHS, RHS, DAG.getConstant(FPCondCCodeToFCC(CC), MVT::i32)); } SDValue MipsTargetLowering:: LowerSELECT(SDValue Op, SelectionDAG &DAG) const { SDValue Cond = Op.getOperand(0); SDValue True = Op.getOperand(1); SDValue False = Op.getOperand(2); DebugLoc dl = Op.getDebugLoc(); // if the incomming condition comes from a integer compare, the select // operation must be SelectCC or a conditional move if the subtarget // supports it. if (Cond.getOpcode() != MipsISD::FPCmp) { if (Subtarget->hasCondMov() && !True.getValueType().isFloatingPoint()) return Op; return DAG.getNode(MipsISD::SelectCC, dl, True.getValueType(), Cond, True, False); } // if the incomming condition comes from fpcmp, the select // operation must use FPSelectCC. SDValue CCNode = Cond.getOperand(2); return DAG.getNode(MipsISD::FPSelectCC, dl, True.getValueType(), Cond, True, False, CCNode); } SDValue MipsTargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const { // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); const GlobalValue *GV = cast(Op)->getGlobal(); if (getTargetMachine().getRelocationModel() != Reloc::PIC_) { SDVTList VTs = DAG.getVTList(MVT::i32); MipsTargetObjectFile &TLOF = (MipsTargetObjectFile&)getObjFileLowering(); // %gp_rel relocation if (TLOF.IsGlobalInSmallSection(GV, getTargetMachine())) { SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_GPREL); SDValue GPRelNode = DAG.getNode(MipsISD::GPRel, dl, VTs, &GA, 1); SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(MVT::i32); return DAG.getNode(ISD::ADD, dl, MVT::i32, GOT, GPRelNode); } // %hi/%lo relocation SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_ABS_HILO); SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, VTs, &GA, 1); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GA); return DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); } else { SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0, MipsII::MO_GOT); SDValue ResNode = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), GA, MachinePointerInfo(), false, false, 0); // On functions and global targets not internal linked only // a load from got/GP is necessary for PIC to work. if (!GV->hasLocalLinkage() || isa(GV)) return ResNode; SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GA); return DAG.getNode(ISD::ADD, dl, MVT::i32, ResNode, Lo); } llvm_unreachable("Dont know how to handle GlobalAddress"); return SDValue(0,0); } SDValue MipsTargetLowering:: LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const { llvm_unreachable("TLS not implemented for MIPS."); return SDValue(); // Not reached } SDValue MipsTargetLowering:: LowerJumpTable(SDValue Op, SelectionDAG &DAG) const { SDValue ResNode; SDValue HiPart; // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_; unsigned char OpFlag = IsPIC ? MipsII::MO_GOT : MipsII::MO_ABS_HILO; EVT PtrVT = Op.getValueType(); JumpTableSDNode *JT = cast(Op); SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, OpFlag); if (!IsPIC) { SDValue Ops[] = { JTI }; HiPart = DAG.getNode(MipsISD::Hi, dl, DAG.getVTList(MVT::i32), Ops, 1); } else // Emit Load from Global Pointer HiPart = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), JTI, MachinePointerInfo(), false, false, 0); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, JTI); ResNode = DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); return ResNode; } SDValue MipsTargetLowering:: LowerConstantPool(SDValue Op, SelectionDAG &DAG) const { SDValue ResNode; ConstantPoolSDNode *N = cast(Op); const Constant *C = N->getConstVal(); // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); // gp_rel relocation // FIXME: we should reference the constant pool using small data sections, // but the asm printer currently doens't support this feature without // hacking it. This feature should come soon so we can uncomment the // stuff below. //if (IsInSmallSection(C->getType())) { // SDValue GPRelNode = DAG.getNode(MipsISD::GPRel, MVT::i32, CP); // SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(MVT::i32); // ResNode = DAG.getNode(ISD::ADD, MVT::i32, GOT, GPRelNode); if (getTargetMachine().getRelocationModel() != Reloc::PIC_) { SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MipsII::MO_ABS_HILO); SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, MVT::i32, CP); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, CP); ResNode = DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo); } else { SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MipsII::MO_GOT); SDValue Load = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), CP, MachinePointerInfo::getConstantPool(), false, false, 0); SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, CP); ResNode = DAG.getNode(ISD::ADD, dl, MVT::i32, Load, Lo); } return ResNode; } SDValue MipsTargetLowering::LowerVASTART(SDValue Op, SelectionDAG &DAG) const { MachineFunction &MF = DAG.getMachineFunction(); MipsFunctionInfo *FuncInfo = MF.getInfo(); DebugLoc dl = Op.getDebugLoc(); SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), getPointerTy()); // vastart just stores the address of the VarArgsFrameIndex slot into the // memory location argument. const Value *SV = cast(Op.getOperand(2))->getValue(); return DAG.getStore(Op.getOperand(0), dl, FI, Op.getOperand(1), MachinePointerInfo(SV), false, false, 0); } //===----------------------------------------------------------------------===// // Calling Convention Implementation //===----------------------------------------------------------------------===// #include "MipsGenCallingConv.inc" //===----------------------------------------------------------------------===// // TODO: Implement a generic logic using tblgen that can support this. // Mips O32 ABI rules: // --- // i32 - Passed in A0, A1, A2, A3 and stack // f32 - Only passed in f32 registers if no int reg has been used yet to hold // an argument. Otherwise, passed in A1, A2, A3 and stack. // f64 - Only passed in two aliased f32 registers if no int reg has been used // yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is // not used, it must be shadowed. If only A3 is avaiable, shadow it and // go to stack. //===----------------------------------------------------------------------===// static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) { static const unsigned IntRegsSize=4, FloatRegsSize=2; static const unsigned IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 }; static const unsigned F32Regs[] = { Mips::F12, Mips::F14 }; static const unsigned F64Regs[] = { Mips::D6, Mips::D7 }; unsigned Reg=0; unsigned UnallocIntReg = State.getFirstUnallocated(IntRegs, IntRegsSize); bool IntRegUsed = (IntRegs[UnallocIntReg] != (unsigned (Mips::A0))); // Promote i8 and i16 if (LocVT == MVT::i8 || LocVT == MVT::i16) { LocVT = MVT::i32; if (ArgFlags.isSExt()) LocInfo = CCValAssign::SExt; else if (ArgFlags.isZExt()) LocInfo = CCValAssign::ZExt; else LocInfo = CCValAssign::AExt; } if (ValVT == MVT::i32 || (ValVT == MVT::f32 && IntRegUsed)) { Reg = State.AllocateReg(IntRegs, IntRegsSize); IntRegUsed = true; LocVT = MVT::i32; } if (ValVT.isFloatingPoint() && !IntRegUsed) { if (ValVT == MVT::f32) Reg = State.AllocateReg(F32Regs, FloatRegsSize); else Reg = State.AllocateReg(F64Regs, FloatRegsSize); } if (ValVT == MVT::f64 && IntRegUsed) { if (UnallocIntReg != IntRegsSize) { // If we hit register A3 as the first not allocated, we must // mark it as allocated (shadow) and use the stack instead. if (IntRegs[UnallocIntReg] != (unsigned (Mips::A3))) Reg = Mips::A2; for (;UnallocIntReg < IntRegsSize; ++UnallocIntReg) State.AllocateReg(UnallocIntReg); } LocVT = MVT::i32; } if (!Reg) { unsigned SizeInBytes = ValVT.getSizeInBits() >> 3; unsigned Offset = State.AllocateStack(SizeInBytes, SizeInBytes); State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo)); } else State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo)); return false; // CC must always match } static bool CC_MipsO32_VarArgs(unsigned ValNo, MVT ValVT, MVT LocVT, CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags, CCState &State) { static const unsigned IntRegsSize=4; static const unsigned IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 }; // Promote i8 and i16 if (LocVT == MVT::i8 || LocVT == MVT::i16) { LocVT = MVT::i32; if (ArgFlags.isSExt()) LocInfo = CCValAssign::SExt; else if (ArgFlags.isZExt()) LocInfo = CCValAssign::ZExt; else LocInfo = CCValAssign::AExt; } if (ValVT == MVT::i32 || ValVT == MVT::f32) { if (unsigned Reg = State.AllocateReg(IntRegs, IntRegsSize)) { State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, MVT::i32, LocInfo)); return false; } unsigned Off = State.AllocateStack(4, 4); State.addLoc(CCValAssign::getMem(ValNo, ValVT, Off, LocVT, LocInfo)); return false; } unsigned UnallocIntReg = State.getFirstUnallocated(IntRegs, IntRegsSize); if (ValVT == MVT::f64) { if (IntRegs[UnallocIntReg] == (unsigned (Mips::A1))) { // A1 can't be used anymore, because 64 bit arguments // must be aligned when copied back to the caller stack State.AllocateReg(IntRegs, IntRegsSize); UnallocIntReg++; } if (IntRegs[UnallocIntReg] == (unsigned (Mips::A0)) || IntRegs[UnallocIntReg] == (unsigned (Mips::A2))) { unsigned Reg = State.AllocateReg(IntRegs, IntRegsSize); State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, MVT::i32, LocInfo)); // Shadow the next register so it can be used // later to get the other 32bit part. State.AllocateReg(IntRegs, IntRegsSize); return false; } // Register is shadowed to preserve alignment, and the // argument goes to a stack location. if (UnallocIntReg != IntRegsSize) State.AllocateReg(IntRegs, IntRegsSize); unsigned Off = State.AllocateStack(8, 8); State.addLoc(CCValAssign::getMem(ValNo, ValVT, Off, LocVT, LocInfo)); return false; } return true; // CC didn't match } //===----------------------------------------------------------------------===// // Call Calling Convention Implementation //===----------------------------------------------------------------------===// /// LowerCall - functions arguments are copied from virtual regs to /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted. /// TODO: isTailCall. SDValue MipsTargetLowering::LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, bool &isTailCall, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // MIPs target does not yet support tail call optimization. isTailCall = false; MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_; // Analyze operands of the call, assigning locations to each operand. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext()); // To meet O32 ABI, Mips must always allocate 16 bytes on // the stack (even if less than 4 are used as arguments) if (Subtarget->isABI_O32()) { int VTsize = MVT(MVT::i32).getSizeInBits()/8; MFI->CreateFixedObject(VTsize, (VTsize*3), true); CCInfo.AnalyzeCallOperands(Outs, isVarArg ? CC_MipsO32_VarArgs : CC_MipsO32); } else CCInfo.AnalyzeCallOperands(Outs, CC_Mips); // Get a count of how many bytes are to be pushed on the stack. unsigned NumBytes = CCInfo.getNextStackOffset(); Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true)); // With EABI is it possible to have 16 args on registers. SmallVector, 16> RegsToPass; SmallVector MemOpChains; // First/LastArgStackLoc contains the first/last // "at stack" argument location. int LastArgStackLoc = 0; unsigned FirstStackArgLoc = (Subtarget->isABI_EABI() ? 0 : 16); // Walk the register/memloc assignments, inserting copies/loads. for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { SDValue Arg = OutVals[i]; CCValAssign &VA = ArgLocs[i]; // Promote the value if needed. switch (VA.getLocInfo()) { default: llvm_unreachable("Unknown loc info!"); case CCValAssign::Full: if (Subtarget->isABI_O32() && VA.isRegLoc()) { if (VA.getValVT() == MVT::f32 && VA.getLocVT() == MVT::i32) Arg = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Arg); if (VA.getValVT() == MVT::f64 && VA.getLocVT() == MVT::i32) { Arg = DAG.getNode(ISD::BITCAST, dl, MVT::i64, Arg); SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Arg, DAG.getConstant(0, getPointerTy())); SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Arg, DAG.getConstant(1, getPointerTy())); RegsToPass.push_back(std::make_pair(VA.getLocReg(), Lo)); RegsToPass.push_back(std::make_pair(VA.getLocReg()+1, Hi)); continue; } } 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)); continue; } // Register can't get to this point... assert(VA.isMemLoc()); // Create the frame index object for this incoming parameter // This guarantees that when allocating Local Area the firsts // 16 bytes which are alwayes reserved won't be overwritten // if O32 ABI is used. For EABI the first address is zero. LastArgStackLoc = (FirstStackArgLoc + VA.getLocMemOffset()); int FI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8, LastArgStackLoc, true); SDValue PtrOff = DAG.getFrameIndex(FI,getPointerTy()); // emit ISD::STORE whichs stores the // parameter value to a stack Location MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo(), false, false, 0)); } // 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[0], MemOpChains.size()); // 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 emited 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/ExternalSymbol node (quite common, every // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol // node so that legalize doesn't hack it. unsigned char OpFlag = IsPIC ? MipsII::MO_GOT_CALL : MipsII::MO_NO_FLAG; if (GlobalAddressSDNode *G = dyn_cast(Callee)) Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0, OpFlag); else if (ExternalSymbolSDNode *S = dyn_cast(Callee)) Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(), OpFlag); // MipsJmpLink = #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::Flag); 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(MipsISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size()); InFlag = Chain.getValue(1); // Create a stack location to hold GP when PIC is used. This stack // location is used on function prologue to save GP and also after all // emited CALL's to restore GP. if (IsPIC) { // Function can have an arbitrary number of calls, so // hold the LastArgStackLoc with the biggest offset. int FI; MipsFunctionInfo *MipsFI = MF.getInfo(); if (LastArgStackLoc >= MipsFI->getGPStackOffset()) { LastArgStackLoc = (!LastArgStackLoc) ? (16) : (LastArgStackLoc+4); // Create the frame index only once. SPOffset here can be anything // (this will be fixed on processFunctionBeforeFrameFinalized) if (MipsFI->getGPStackOffset() == -1) { FI = MFI->CreateFixedObject(4, 0, true); MipsFI->setGPFI(FI); } MipsFI->setGPStackOffset(LastArgStackLoc); } // Reload GP value. FI = MipsFI->getGPFI(); SDValue FIN = DAG.getFrameIndex(FI, getPointerTy()); SDValue GPLoad = DAG.getLoad(MVT::i32, dl, Chain, FIN, MachinePointerInfo::getFixedStack(FI), false, false, 0); Chain = GPLoad.getValue(1); Chain = DAG.getCopyToReg(Chain, dl, DAG.getRegister(Mips::GP, MVT::i32), GPLoad, SDValue(0,0)); InFlag = Chain.getValue(1); } // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true), DAG.getIntPtrConstant(0, true), InFlag); 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 MipsTargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // Assign locations to each value returned by this call. SmallVector RVLocs; CCState CCInfo(CallConv, isVarArg, getTargetMachine(), RVLocs, *DAG.getContext()); CCInfo.AnalyzeCallResult(Ins, RetCC_Mips); // 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; } //===----------------------------------------------------------------------===// // Formal Arguments Calling Convention Implementation //===----------------------------------------------------------------------===// /// LowerFormalArguments - transform physical registers into virtual registers /// and generate load operations for arguments places on the stack. SDValue MipsTargetLowering::LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) const { MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); MipsFunctionInfo *MipsFI = MF.getInfo(); unsigned StackReg = MF.getTarget().getRegisterInfo()->getFrameRegister(MF); MipsFI->setVarArgsFrameIndex(0); // Used with vargs to acumulate store chains. std::vector OutChains; // Keep track of the last register used for arguments unsigned ArgRegEnd = 0; // Assign locations to all of the incoming arguments. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext()); if (Subtarget->isABI_O32()) CCInfo.AnalyzeFormalArguments(Ins, isVarArg ? CC_MipsO32_VarArgs : CC_MipsO32); else CCInfo.AnalyzeFormalArguments(Ins, CC_Mips); SDValue StackPtr; unsigned FirstStackArgLoc = (Subtarget->isABI_EABI() ? 0 : 16); for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign &VA = ArgLocs[i]; // Arguments stored on registers if (VA.isRegLoc()) { EVT RegVT = VA.getLocVT(); ArgRegEnd = VA.getLocReg(); TargetRegisterClass *RC = 0; if (RegVT == MVT::i32) RC = Mips::CPURegsRegisterClass; else if (RegVT == MVT::f32) RC = Mips::FGR32RegisterClass; else if (RegVT == MVT::f64) { if (!Subtarget->isSingleFloat()) RC = Mips::AFGR64RegisterClass; } else llvm_unreachable("RegVT not supported by FormalArguments Lowering"); // Transform the arguments stored on // physical registers into virtual ones unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegEnd, RC); SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT); // If this is an 8 or 16-bit value, it has been passed promoted // to 32 bits. Insert an assert[sz]ext to capture this, then // truncate to the right size. if (VA.getLocInfo() != CCValAssign::Full) { unsigned Opcode = 0; if (VA.getLocInfo() == CCValAssign::SExt) Opcode = ISD::AssertSext; else if (VA.getLocInfo() == CCValAssign::ZExt) Opcode = ISD::AssertZext; if (Opcode) ArgValue = DAG.getNode(Opcode, dl, RegVT, ArgValue, DAG.getValueType(VA.getValVT())); ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue); } // Handle O32 ABI cases: i32->f32 and (i32,i32)->f64 if (Subtarget->isABI_O32()) { if (RegVT == MVT::i32 && VA.getValVT() == MVT::f32) ArgValue = DAG.getNode(ISD::BITCAST, dl, MVT::f32, ArgValue); if (RegVT == MVT::i32 && VA.getValVT() == MVT::f64) { unsigned Reg2 = AddLiveIn(DAG.getMachineFunction(), VA.getLocReg()+1, RC); SDValue ArgValue2 = DAG.getCopyFromReg(Chain, dl, Reg2, RegVT); SDValue Hi = DAG.getNode(ISD::BITCAST, dl, MVT::f32, ArgValue); SDValue Lo = DAG.getNode(ISD::BITCAST, dl, MVT::f32, ArgValue2); ArgValue = DAG.getNode(ISD::BUILD_PAIR, dl, MVT::f64, Lo, Hi); } } InVals.push_back(ArgValue); } else { // VA.isRegLoc() // sanity check assert(VA.isMemLoc()); // The last argument is not a register anymore ArgRegEnd = 0; // The stack pointer offset is relative to the caller stack frame. // Since the real stack size is unknown here, a negative SPOffset // is used so there's a way to adjust these offsets when the stack // size get known (on EliminateFrameIndex). A dummy SPOffset is // used instead of a direct negative address (which is recorded to // be used on emitPrologue) to avoid mis-calc of the first stack // offset on PEI::calculateFrameObjectOffsets. // Arguments are always 32-bit. unsigned ArgSize = VA.getLocVT().getSizeInBits()/8; int FI = MFI->CreateFixedObject(ArgSize, 0, true); MipsFI->recordLoadArgsFI(FI, -(ArgSize+ (FirstStackArgLoc + VA.getLocMemOffset()))); // Create load nodes to retrieve arguments from the stack SDValue FIN = DAG.getFrameIndex(FI, getPointerTy()); InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN, MachinePointerInfo::getFixedStack(FI), false, false, 0)); } } // The mips ABIs for returning structs by value requires that we copy // the sret argument into $v0 for the return. Save the argument into // a virtual register so that we can access it from the return points. if (DAG.getMachineFunction().getFunction()->hasStructRetAttr()) { unsigned Reg = MipsFI->getSRetReturnReg(); if (!Reg) { Reg = MF.getRegInfo().createVirtualRegister(getRegClassFor(MVT::i32)); MipsFI->setSRetReturnReg(Reg); } SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[0]); Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain); } // To meet ABI, when VARARGS are passed on registers, the registers // must have their values written to the caller stack frame. If the last // argument was placed in the stack, there's no need to save any register. if ((isVarArg) && (Subtarget->isABI_O32() && ArgRegEnd)) { if (StackPtr.getNode() == 0) StackPtr = DAG.getRegister(StackReg, getPointerTy()); // The last register argument that must be saved is Mips::A3 TargetRegisterClass *RC = Mips::CPURegsRegisterClass; unsigned StackLoc = ArgLocs.size()-1; for (++ArgRegEnd; ArgRegEnd <= Mips::A3; ++ArgRegEnd, ++StackLoc) { unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegEnd, RC); SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, MVT::i32); int FI = MFI->CreateFixedObject(4, 0, true); MipsFI->recordStoreVarArgsFI(FI, -(4+(StackLoc*4))); SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy()); OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff, MachinePointerInfo(), false, false, 0)); // Record the frame index of the first variable argument // which is a value necessary to VASTART. if (!MipsFI->getVarArgsFrameIndex()) MipsFI->setVarArgsFrameIndex(FI); } } // All stores are grouped in one node to allow the matching between // the size of Ins and InVals. This only happens when on varg functions if (!OutChains.empty()) { OutChains.push_back(Chain); Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &OutChains[0], OutChains.size()); } return Chain; } //===----------------------------------------------------------------------===// // Return Value Calling Convention Implementation //===----------------------------------------------------------------------===// SDValue MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, DebugLoc dl, SelectionDAG &DAG) const { // CCValAssign - represent the assignment of // the return value to a location SmallVector RVLocs; // CCState - Info about the registers and stack slot. CCState CCInfo(CallConv, isVarArg, getTargetMachine(), RVLocs, *DAG.getContext()); // Analize return values. CCInfo.AnalyzeReturn(Outs, RetCC_Mips); // If this is the first return lowered for this function, add // the regs to the liveout set for the function. if (DAG.getMachineFunction().getRegInfo().liveout_empty()) { for (unsigned i = 0; i != RVLocs.size(); ++i) if (RVLocs[i].isRegLoc()) DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg()); } SDValue Flag; // 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); } // The mips ABIs for returning structs by value requires that we copy // the sret argument into $v0 for the return. We saved the argument into // a virtual register in the entry block, so now we copy the value out // and into $v0. if (DAG.getMachineFunction().getFunction()->hasStructRetAttr()) { MachineFunction &MF = DAG.getMachineFunction(); MipsFunctionInfo *MipsFI = MF.getInfo(); unsigned Reg = MipsFI->getSRetReturnReg(); if (!Reg) llvm_unreachable("sret virtual register not created in the entry block"); SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy()); Chain = DAG.getCopyToReg(Chain, dl, Mips::V0, Val, Flag); Flag = Chain.getValue(1); } // Return on Mips is always a "jr $ra" if (Flag.getNode()) return DAG.getNode(MipsISD::Ret, dl, MVT::Other, Chain, DAG.getRegister(Mips::RA, MVT::i32), Flag); else // Return Void return DAG.getNode(MipsISD::Ret, dl, MVT::Other, Chain, DAG.getRegister(Mips::RA, MVT::i32)); } //===----------------------------------------------------------------------===// // Mips Inline Assembly Support //===----------------------------------------------------------------------===// /// getConstraintType - Given a constraint letter, return the type of /// constraint it is for this target. MipsTargetLowering::ConstraintType MipsTargetLowering:: getConstraintType(const std::string &Constraint) const { // Mips specific constrainy // GCC config/mips/constraints.md // // 'd' : An address register. Equivalent to r // unless generating MIPS16 code. // 'y' : Equivalent to r; retained for // backwards compatibility. // 'f' : Floating Point registers. if (Constraint.size() == 1) { switch (Constraint[0]) { default : break; case 'd': case 'y': case 'f': return C_RegisterClass; break; } } return TargetLowering::getConstraintType(Constraint); } /// Examine constraint type and operand type and determine a weight value. /// This object must already have been set up with the operand type /// and the current alternative constraint selected. TargetLowering::ConstraintWeight MipsTargetLowering::getSingleConstraintMatchWeight( AsmOperandInfo &info, const char *constraint) const { ConstraintWeight weight = CW_Invalid; Value *CallOperandVal = info.CallOperandVal; // If we don't have a value, we can't do a match, // but allow it at the lowest weight. if (CallOperandVal == NULL) return CW_Default; const Type *type = CallOperandVal->getType(); // Look at the constraint type. switch (*constraint) { default: weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint); break; case 'd': case 'y': if (type->isIntegerTy()) weight = CW_Register; break; case 'f': if (type->isFloatTy()) weight = CW_Register; break; } return weight; } /// getRegClassForInlineAsmConstraint - Given a constraint letter (e.g. "r"), /// return a list of registers that can be used to satisfy the constraint. /// This should only be used for C_RegisterClass constraints. std::pair MipsTargetLowering:: getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const { if (Constraint.size() == 1) { switch (Constraint[0]) { case 'r': return std::make_pair(0U, Mips::CPURegsRegisterClass); case 'f': if (VT == MVT::f32) return std::make_pair(0U, Mips::FGR32RegisterClass); if (VT == MVT::f64) if ((!Subtarget->isSingleFloat()) && (!Subtarget->isFP64bit())) return std::make_pair(0U, Mips::AFGR64RegisterClass); } } return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT); } /// Given a register class constraint, like 'r', if this corresponds directly /// to an LLVM register class, return a register of 0 and the register class /// pointer. std::vector MipsTargetLowering:: getRegClassForInlineAsmConstraint(const std::string &Constraint, EVT VT) const { if (Constraint.size() != 1) return std::vector(); switch (Constraint[0]) { default : break; case 'r': // GCC Mips Constraint Letters case 'd': case 'y': return make_vector(Mips::T0, Mips::T1, Mips::T2, Mips::T3, Mips::T4, Mips::T5, Mips::T6, Mips::T7, Mips::S0, Mips::S1, Mips::S2, Mips::S3, Mips::S4, Mips::S5, Mips::S6, Mips::S7, Mips::T8, 0); case 'f': if (VT == MVT::f32) { if (Subtarget->isSingleFloat()) return make_vector(Mips::F2, Mips::F3, Mips::F4, Mips::F5, Mips::F6, Mips::F7, Mips::F8, Mips::F9, Mips::F10, Mips::F11, Mips::F20, Mips::F21, Mips::F22, Mips::F23, Mips::F24, Mips::F25, Mips::F26, Mips::F27, Mips::F28, Mips::F29, Mips::F30, Mips::F31, 0); else return make_vector(Mips::F2, Mips::F4, Mips::F6, Mips::F8, Mips::F10, Mips::F20, Mips::F22, Mips::F24, Mips::F26, Mips::F28, Mips::F30, 0); } if (VT == MVT::f64) if ((!Subtarget->isSingleFloat()) && (!Subtarget->isFP64bit())) return make_vector(Mips::D1, Mips::D2, Mips::D3, Mips::D4, Mips::D5, Mips::D10, Mips::D11, Mips::D12, Mips::D13, Mips::D14, Mips::D15, 0); } return std::vector(); } bool MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const { // The Mips target isn't yet aware of offsets. return false; } bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const { if (VT != MVT::f32 && VT != MVT::f64) return false; return Imm.isZero(); }