//===-- MBlazeISelLowering.cpp - MBlaze 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 MBlaze uses to lower LLVM code into a // selection DAG. // //===----------------------------------------------------------------------===// #define DEBUG_TYPE "mblaze-lower" #include "MBlazeISelLowering.h" #include "MBlazeMachineFunction.h" #include "MBlazeTargetMachine.h" #include "MBlazeTargetObjectFile.h" #include "MBlazeSubtarget.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" #include "llvm/Support/raw_ostream.h" using namespace llvm; const char *MBlazeTargetLowering::getTargetNodeName(unsigned Opcode) const { switch (Opcode) { case MBlazeISD::JmpLink : return "MBlazeISD::JmpLink"; case MBlazeISD::GPRel : return "MBlazeISD::GPRel"; case MBlazeISD::Wrap : return "MBlazeISD::Wrap"; case MBlazeISD::ICmp : return "MBlazeISD::ICmp"; case MBlazeISD::Ret : return "MBlazeISD::Ret"; case MBlazeISD::Select_CC : return "MBlazeISD::Select_CC"; default : return NULL; } } MBlazeTargetLowering::MBlazeTargetLowering(MBlazeTargetMachine &TM) : TargetLowering(TM, new MBlazeTargetObjectFile()) { Subtarget = &TM.getSubtarget(); // MBlaze does not have i1 type, so use i32 for // setcc operations results (slt, sgt, ...). setBooleanContents(ZeroOrOneBooleanContent); // Set up the register classes addRegisterClass(MVT::i32, MBlaze::CPURegsRegisterClass); if (Subtarget->hasFPU()) { addRegisterClass(MVT::f32, MBlaze::FGR32RegisterClass); setOperationAction(ISD::ConstantFP, MVT::f32, Legal); } // Floating point operations which are not supported setOperationAction(ISD::FREM, MVT::f32, Expand); setOperationAction(ISD::UINT_TO_FP, MVT::i8, Expand); setOperationAction(ISD::UINT_TO_FP, MVT::i16, Expand); setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand); setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand); setOperationAction(ISD::FP_ROUND, MVT::f32, Expand); setOperationAction(ISD::FP_ROUND, MVT::f64, 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); // 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); // MBlaze has no REM or DIVREM operations. setOperationAction(ISD::UREM, MVT::i32, Expand); setOperationAction(ISD::SREM, MVT::i32, Expand); setOperationAction(ISD::SDIVREM, MVT::i32, Expand); setOperationAction(ISD::UDIVREM, MVT::i32, Expand); // If the processor doesn't support multiply then expand it if (!Subtarget->hasMul()) { setOperationAction(ISD::MUL, MVT::i32, Expand); } // If the processor doesn't support 64-bit multiply then expand if (!Subtarget->hasMul() || !Subtarget->hasMul64()) { setOperationAction(ISD::MULHS, MVT::i32, Expand); setOperationAction(ISD::MULHS, MVT::i64, Expand); setOperationAction(ISD::MULHU, MVT::i32, Expand); setOperationAction(ISD::MULHU, MVT::i64, Expand); } // If the processor doesn't support division then expand if (!Subtarget->hasDiv()) { setOperationAction(ISD::UDIV, MVT::i32, Expand); setOperationAction(ISD::SDIV, MVT::i32, Expand); } // Expand unsupported conversions setOperationAction(ISD::BIT_CONVERT, MVT::f32, Expand); setOperationAction(ISD::BIT_CONVERT, MVT::i32, Expand); // Expand SELECT_CC setOperationAction(ISD::SELECT_CC, MVT::Other, Expand); // MBlaze doesn't have MUL_LOHI setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand); setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand); setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand); setOperationAction(ISD::UMUL_LOHI, MVT::i64, 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); AddPromotedToType(ISD::SELECT, MVT::i1, MVT::i32); AddPromotedToType(ISD::SELECT_CC, MVT::i1, MVT::i32); // MBlaze 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); // Operations not directly supported by MBlaze. setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand); setOperationAction(ISD::BR_JT, MVT::Other, Expand); setOperationAction(ISD::BR_CC, MVT::Other, Expand); setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand); setOperationAction(ISD::ROTL, MVT::i32, Expand); 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::CTLZ, MVT::i32, Expand); setOperationAction(ISD::CTTZ, MVT::i32, Expand); setOperationAction(ISD::CTPOP, MVT::i32, Expand); setOperationAction(ISD::BSWAP, MVT::i32, Expand); // We don't have line number support yet. 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); // MBlaze doesn't have extending float->double load/store setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand); setTruncStoreAction(MVT::f64, MVT::f32, Expand); setStackPointerRegisterToSaveRestore(MBlaze::R1); computeRegisterProperties(); } MVT::SimpleValueType MBlazeTargetLowering::getSetCCResultType(EVT VT) const { return MVT::i32; } /// getFunctionAlignment - Return the Log2 alignment of this function. unsigned MBlazeTargetLowering::getFunctionAlignment(const Function *) const { return 2; } SDValue MBlazeTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) { switch (Op.getOpcode()) { case ISD::ConstantPool: return LowerConstantPool(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::SELECT_CC: return LowerSELECT_CC(Op, DAG); } return SDValue(); } //===----------------------------------------------------------------------===// // Lower helper functions //===----------------------------------------------------------------------===// MachineBasicBlock* MBlazeTargetLowering:: EmitInstrWithCustomInserter(MachineInstr *MI, MachineBasicBlock *BB, DenseMap *EM) const { const TargetInstrInfo *TII = getTargetMachine().getInstrInfo(); DebugLoc dl = MI->getDebugLoc(); switch (MI->getOpcode()) { default: assert(false && "Unexpected instr type to insert"); case MBlaze::ShiftRL: case MBlaze::ShiftRA: case MBlaze::ShiftL: { // To "insert" a shift left instruction, we actually have to insert a // simple loop. The incoming instruction knows the destination vreg to // set, the source vreg to operate over and the shift amount. const BasicBlock *LLVM_BB = BB->getBasicBlock(); MachineFunction::iterator It = BB; ++It; // start: // andi samt, samt, 31 // beqid samt, finish // add dst, src, r0 // loop: // addik samt, samt, -1 // sra dst, dst // bneid samt, loop // nop // finish: MachineFunction *F = BB->getParent(); MachineRegisterInfo &R = F->getRegInfo(); MachineBasicBlock *loop = F->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *finish = F->CreateMachineBasicBlock(LLVM_BB); unsigned IAMT = R.createVirtualRegister(MBlaze::CPURegsRegisterClass); BuildMI(BB, dl, TII->get(MBlaze::ANDI), IAMT) .addReg(MI->getOperand(2).getReg()) .addImm(31); unsigned IVAL = R.createVirtualRegister(MBlaze::CPURegsRegisterClass); BuildMI(BB, dl, TII->get(MBlaze::ADDI), IVAL) .addReg(MI->getOperand(1).getReg()) .addImm(0); BuildMI(BB, dl, TII->get(MBlaze::BEQID)) .addReg(IAMT) .addMBB(finish); F->insert(It, loop); F->insert(It, finish); // Update machine-CFG edges by first adding all successors of the current // block to the new block which will contain the Phi node for the select. // Also inform sdisel of the edge changes. for(MachineBasicBlock::succ_iterator i = BB->succ_begin(), e = BB->succ_end(); i != e; ++i) { EM->insert(std::make_pair(*i, finish)); finish->addSuccessor(*i); } // Next, remove all successors of the current block, and add the true // and fallthrough blocks as its successors. while(!BB->succ_empty()) BB->removeSuccessor(BB->succ_begin()); BB->addSuccessor(loop); BB->addSuccessor(finish); // Next, add the finish block as a successor of the loop block loop->addSuccessor(finish); loop->addSuccessor(loop); unsigned DST = R.createVirtualRegister(MBlaze::CPURegsRegisterClass); unsigned NDST = R.createVirtualRegister(MBlaze::CPURegsRegisterClass); BuildMI(loop, dl, TII->get(MBlaze::PHI), DST) .addReg(IVAL).addMBB(BB) .addReg(NDST).addMBB(loop); unsigned SAMT = R.createVirtualRegister(MBlaze::CPURegsRegisterClass); unsigned NAMT = R.createVirtualRegister(MBlaze::CPURegsRegisterClass); BuildMI(loop, dl, TII->get(MBlaze::PHI), SAMT) .addReg(IAMT).addMBB(BB) .addReg(NAMT).addMBB(loop); if (MI->getOpcode() == MBlaze::ShiftL) BuildMI(loop, dl, TII->get(MBlaze::ADD), NDST).addReg(DST).addReg(DST); else if (MI->getOpcode() == MBlaze::ShiftRA) BuildMI(loop, dl, TII->get(MBlaze::SRA), NDST).addReg(DST); else if (MI->getOpcode() == MBlaze::ShiftRL) BuildMI(loop, dl, TII->get(MBlaze::SRL), NDST).addReg(DST); else llvm_unreachable( "Cannot lower unknown shift instruction" ); BuildMI(loop, dl, TII->get(MBlaze::ADDI), NAMT) .addReg(SAMT) .addImm(-1); BuildMI(loop, dl, TII->get(MBlaze::BNEID)) .addReg(NAMT) .addMBB(loop); BuildMI(finish, dl, TII->get(MBlaze::PHI), MI->getOperand(0).getReg()) .addReg(IVAL).addMBB(BB) .addReg(NDST).addMBB(loop); // The pseudo instruction is no longer needed so remove it F->DeleteMachineInstr(MI); return finish; } case MBlaze::Select_FCC: case MBlaze::Select_CC: { // 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 MachineFunction *F = BB->getParent(); MachineBasicBlock *flsBB = F->CreateMachineBasicBlock(LLVM_BB); MachineBasicBlock *dneBB = F->CreateMachineBasicBlock(LLVM_BB); unsigned Opc; switch (MI->getOperand(4).getImm()) { default: llvm_unreachable( "Unknown branch condition" ); case MBlazeCC::EQ: Opc = MBlaze::BNEID; break; case MBlazeCC::NE: Opc = MBlaze::BEQID; break; case MBlazeCC::GT: Opc = MBlaze::BLEID; break; case MBlazeCC::LT: Opc = MBlaze::BGEID; break; case MBlazeCC::GE: Opc = MBlaze::BLTID; break; case MBlazeCC::LE: Opc = MBlaze::BGTID; break; } BuildMI(BB, dl, TII->get(Opc)) .addReg(MI->getOperand(3).getReg()) .addMBB(dneBB); F->insert(It, flsBB); F->insert(It, dneBB); // Update machine-CFG edges by first adding all successors of the current // block to the new block which will contain the Phi node for the select. // Also inform sdisel of the edge changes. for(MachineBasicBlock::succ_iterator i = BB->succ_begin(), e = BB->succ_end(); i != e; ++i) { EM->insert(std::make_pair(*i, dneBB)); dneBB->addSuccessor(*i); } // Next, remove all successors of the current block, and add the true // and fallthrough blocks as its successors. while(!BB->succ_empty()) BB->removeSuccessor(BB->succ_begin()); BB->addSuccessor(flsBB); BB->addSuccessor(dneBB); flsBB->addSuccessor(dneBB); // sinkMBB: // %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ] // ... //BuildMI(dneBB, dl, TII->get(MBlaze::PHI), MI->getOperand(0).getReg()) // .addReg(MI->getOperand(1).getReg()).addMBB(flsBB) // .addReg(MI->getOperand(2).getReg()).addMBB(BB); BuildMI(dneBB, dl, TII->get(MBlaze::PHI), MI->getOperand(0).getReg()) .addReg(MI->getOperand(2).getReg()).addMBB(flsBB) .addReg(MI->getOperand(1).getReg()).addMBB(BB); F->DeleteMachineInstr(MI); // The pseudo instruction is gone now. return dneBB; } } } //===----------------------------------------------------------------------===// // Misc Lower Operation implementation //===----------------------------------------------------------------------===// // SDValue MBlazeTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) { SDValue LHS = Op.getOperand(0); SDValue RHS = Op.getOperand(1); SDValue TrueVal = Op.getOperand(2); SDValue FalseVal = Op.getOperand(3); DebugLoc dl = Op.getDebugLoc(); unsigned Opc; SDValue CompareFlag; if (LHS.getValueType() == MVT::i32) { Opc = MBlazeISD::Select_CC; CompareFlag = DAG.getNode(MBlazeISD::ICmp, dl, MVT::i32, LHS, RHS) .getValue(1); } else { llvm_unreachable( "Cannot lower select_cc with unknown type" ); } return DAG.getNode(Opc, dl, TrueVal.getValueType(), TrueVal, FalseVal, CompareFlag); } SDValue MBlazeTargetLowering:: LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) { // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); GlobalValue *GV = cast(Op)->getGlobal(); SDValue GA = DAG.getTargetGlobalAddress(GV, MVT::i32); return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, GA); } SDValue MBlazeTargetLowering:: LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) { llvm_unreachable("TLS not implemented for MicroBlaze."); return SDValue(); // Not reached } SDValue MBlazeTargetLowering:: LowerJumpTable(SDValue Op, SelectionDAG &DAG) { 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 ? MBlazeII::MO_GOT : MBlazeII::MO_ABS_HILO; EVT PtrVT = Op.getValueType(); JumpTableSDNode *JT = cast(Op); SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, OpFlag); return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, JTI); //return JTI; } SDValue MBlazeTargetLowering:: LowerConstantPool(SDValue Op, SelectionDAG &DAG) { SDValue ResNode; EVT PtrVT = Op.getValueType(); ConstantPoolSDNode *N = cast(Op); Constant *C = N->getConstVal(); SDValue Zero = DAG.getConstant(0, PtrVT); // FIXME there isn't actually debug info here DebugLoc dl = Op.getDebugLoc(); SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(), N->getOffset(), MBlazeII::MO_ABS_HILO); return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, CP); } //===----------------------------------------------------------------------===// // Calling Convention Implementation //===----------------------------------------------------------------------===// #include "MBlazeGenCallingConv.inc" //===----------------------------------------------------------------------===// // 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: isVarArg, isTailCall. SDValue MBlazeTargetLowering:: LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, bool &isTailCall, const SmallVectorImpl &Outs, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) { MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); // Analyze operands of the call, assigning locations to each operand. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext()); CCInfo.AnalyzeCallOperands(Outs, CC_MBlaze); // 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)); SmallVector, 8> RegsToPass; SmallVector MemOpChains; // First/LastArgStackLoc contains the first/last // "at stack" argument location. int LastArgStackLoc = 0; unsigned FirstStackArgLoc = 4; // Walk the register/memloc assignments, inserting copies/loads. for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) { CCValAssign &VA = ArgLocs[i]; EVT RegVT = VA.getLocVT(); SDValue Arg = Outs[i].Val; // 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, RegVT, Arg); break; case CCValAssign::ZExt: Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, RegVT, Arg); break; case CCValAssign::AExt: Arg = DAG.getNode(ISD::ANY_EXTEND, dl, RegVT, Arg); break; case CCValAssign::BCvt: Arg = DAG.getNode(ISD::BIT_CONVERT, dl, RegVT, 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 { // Register can't get to this point... assert(VA.isMemLoc()); // Create the frame index object for this incoming parameter LastArgStackLoc = (FirstStackArgLoc + VA.getLocMemOffset()); int FI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8, LastArgStackLoc, true, false); 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, NULL, 0, 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 = MBlazeII::MO_NO_FLAG; if (GlobalAddressSDNode *G = dyn_cast(Callee)) Callee = DAG.getTargetGlobalAddress(G->getGlobal(), getPointerTy(), 0, OpFlag); else if (ExternalSymbolSDNode *S = dyn_cast(Callee)) Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(), OpFlag); // MBlazeJmpLink = #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(MBlazeISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size()); InFlag = Chain.getValue(1); // Create the CALLSEQ_END node. Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true), DAG.getIntPtrConstant(0, true), InFlag); if (!Ins.empty()) 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 MBlazeTargetLowering:: LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) { // Assign locations to each value returned by this call. SmallVector RVLocs; CCState CCInfo(CallConv, isVarArg, getTargetMachine(), RVLocs, *DAG.getContext()); CCInfo.AnalyzeCallResult(Ins, RetCC_MBlaze); // 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. /// TODO: isVarArg SDValue MBlazeTargetLowering:: LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl &InVals) { MachineFunction &MF = DAG.getMachineFunction(); MachineFrameInfo *MFI = MF.getFrameInfo(); MBlazeFunctionInfo *MBlazeFI = MF.getInfo(); unsigned StackReg = MF.getTarget().getRegisterInfo()->getFrameRegister(MF); // Assign locations to all of the incoming arguments. SmallVector ArgLocs; CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext()); CCInfo.AnalyzeFormalArguments(Ins, CC_MBlaze); SDValue StackPtr; unsigned FirstStackArgLoc = 4; 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(); TargetRegisterClass *RC = 0; if (RegVT == MVT::i32) RC = MBlaze::CPURegsRegisterClass; else if (RegVT == MVT::f32) RC = MBlaze::FGR32RegisterClass; else llvm_unreachable("RegVT not supported by LowerFormalArguments"); // Transform the arguments stored on // physical registers into virtual ones unsigned Reg = MF.addLiveIn(VA.getLocReg(), 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); } InVals.push_back(ArgValue); // To meet ABI, when VARARGS are passed on registers, the registers // must have their values written to the caller stack frame. if (isVarArg) { if (StackPtr.getNode() == 0) StackPtr = DAG.getRegister(StackReg, getPointerTy()); // 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. int FI = MFI->CreateFixedObject(4, 0, true, false); MBlazeFI->recordStoreVarArgsFI(FI, -(FirstStackArgLoc+(i*4))); SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy()); // emit ISD::STORE whichs stores the // parameter value to a stack Location InVals.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff, NULL, 0, false, false, 0)); } } else { // VA.isRegLoc() // sanity check assert(VA.isMemLoc()); // 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, false); MBlazeFI->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, NULL, 0, false, false, 0)); } } return Chain; } //===----------------------------------------------------------------------===// // Return Value Calling Convention Implementation //===----------------------------------------------------------------------===// SDValue MBlazeTargetLowering:: LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Outs, DebugLoc dl, SelectionDAG &DAG) { // 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_MBlaze); // 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(), Outs[i].Val, Flag); // guarantee that all emitted copies are // stuck together, avoiding something bad Flag = Chain.getValue(1); } // Return on MBlaze is always a "rtsd R15, 8" if (Flag.getNode()) return DAG.getNode(MBlazeISD::Ret, dl, MVT::Other, Chain, DAG.getRegister(MBlaze::R15, MVT::i32), Flag); else // Return Void return DAG.getNode(MBlazeISD::Ret, dl, MVT::Other, Chain, DAG.getRegister(MBlaze::R15, MVT::i32)); } //===----------------------------------------------------------------------===// // MBlaze Inline Assembly Support //===----------------------------------------------------------------------===// /// getConstraintType - Given a constraint letter, return the type of /// constraint it is for this target. MBlazeTargetLowering::ConstraintType MBlazeTargetLowering:: getConstraintType(const std::string &Constraint) const { // MBlaze specific constrainy // // 'd' : An address register. Equivalent to r. // '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); } /// 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 MBlazeTargetLowering:: getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const { if (Constraint.size() == 1) { switch (Constraint[0]) { case 'r': return std::make_pair(0U, MBlaze::CPURegsRegisterClass); case 'f': if (VT == MVT::f32) return std::make_pair(0U, MBlaze::FGR32RegisterClass); } } 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 MBlazeTargetLowering:: getRegClassForInlineAsmConstraint(const std::string &Constraint, EVT VT) const { if (Constraint.size() != 1) return std::vector(); switch (Constraint[0]) { default : break; case 'r': // GCC MBlaze Constraint Letters case 'd': case 'y': return make_vector( MBlaze::R3, MBlaze::R4, MBlaze::R5, MBlaze::R6, MBlaze::R7, MBlaze::R9, MBlaze::R10, MBlaze::R11, MBlaze::R12, MBlaze::R19, MBlaze::R20, MBlaze::R21, MBlaze::R22, MBlaze::R23, MBlaze::R24, MBlaze::R25, MBlaze::R26, MBlaze::R27, MBlaze::R28, MBlaze::R29, MBlaze::R30, MBlaze::R31, 0); case 'f': return make_vector( MBlaze::F3, MBlaze::F4, MBlaze::F5, MBlaze::F6, MBlaze::F7, MBlaze::F9, MBlaze::F10, MBlaze::F11, MBlaze::F12, MBlaze::F19, MBlaze::F20, MBlaze::F21, MBlaze::F22, MBlaze::F23, MBlaze::F24, MBlaze::F25, MBlaze::F26, MBlaze::F27, MBlaze::F28, MBlaze::F29, MBlaze::F30, MBlaze::F31, 0); } return std::vector(); } bool MBlazeTargetLowering:: isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const { // The MBlaze target isn't yet aware of offsets. return false; } bool MBlazeTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const { return VT != MVT::f32; }