unsigned FastISel::getRegForGEPIndex(Value *Idx) { unsigned IdxN = getRegForValue(Idx); if (IdxN == 0) // Unhandled operand. Halt "fast" selection and bail. return 0; // If the index is smaller or larger than intptr_t, truncate or extend it. MVT PtrVT = TLI.getPointerTy(); EVT IdxVT = EVT::getEVT(Idx->getType(), /*HandleUnknown=*/false); if (IdxVT.bitsLT(PtrVT)) IdxN = FastEmit_r(IdxVT.getSimpleVT(), PtrVT, ISD::SIGN_EXTEND, IdxN); else if (IdxVT.bitsGT(PtrVT)) IdxN = FastEmit_r(IdxVT.getSimpleVT(), PtrVT, ISD::TRUNCATE, IdxN); return IdxN; }
std::pair<unsigned, bool> FastISel::getRegForGEPIndex(const Value *Idx) { unsigned IdxN = getRegForValue(Idx); if (IdxN == 0) // Unhandled operand. Halt "fast" selection and bail. return std::pair<unsigned, bool>(0, false); bool IdxNIsKill = hasTrivialKill(Idx); // If the index is smaller or larger than intptr_t, truncate or extend it. MVT PtrVT = TLI.getPointerTy(); EVT IdxVT = EVT::getEVT(Idx->getType(), /*HandleUnknown=*/false); if (IdxVT.bitsLT(PtrVT)) { IdxN = FastEmit_r(IdxVT.getSimpleVT(), PtrVT, ISD::SIGN_EXTEND, IdxN, IdxNIsKill); IdxNIsKill = true; } else if (IdxVT.bitsGT(PtrVT)) { IdxN = FastEmit_r(IdxVT.getSimpleVT(), PtrVT, ISD::TRUNCATE, IdxN, IdxNIsKill); IdxNIsKill = true; } return std::pair<unsigned, bool>(IdxN, IdxNIsKill); }
bool FastISel::SelectOperator(const User *I, unsigned Opcode) { switch (Opcode) { case Instruction::Add: return SelectBinaryOp(I, ISD::ADD); case Instruction::FAdd: return SelectBinaryOp(I, ISD::FADD); case Instruction::Sub: return SelectBinaryOp(I, ISD::SUB); case Instruction::FSub: // FNeg is currently represented in LLVM IR as a special case of FSub. if (BinaryOperator::isFNeg(I)) return SelectFNeg(I); return SelectBinaryOp(I, ISD::FSUB); case Instruction::Mul: return SelectBinaryOp(I, ISD::MUL); case Instruction::FMul: return SelectBinaryOp(I, ISD::FMUL); case Instruction::SDiv: return SelectBinaryOp(I, ISD::SDIV); case Instruction::UDiv: return SelectBinaryOp(I, ISD::UDIV); case Instruction::FDiv: return SelectBinaryOp(I, ISD::FDIV); case Instruction::SRem: return SelectBinaryOp(I, ISD::SREM); case Instruction::URem: return SelectBinaryOp(I, ISD::UREM); case Instruction::FRem: return SelectBinaryOp(I, ISD::FREM); case Instruction::Shl: return SelectBinaryOp(I, ISD::SHL); case Instruction::LShr: return SelectBinaryOp(I, ISD::SRL); case Instruction::AShr: return SelectBinaryOp(I, ISD::SRA); case Instruction::And: return SelectBinaryOp(I, ISD::AND); case Instruction::Or: return SelectBinaryOp(I, ISD::OR); case Instruction::Xor: return SelectBinaryOp(I, ISD::XOR); case Instruction::GetElementPtr: return SelectGetElementPtr(I); case Instruction::Br: { const BranchInst *BI = cast<BranchInst>(I); if (BI->isUnconditional()) { const BasicBlock *LLVMSucc = BI->getSuccessor(0); MachineBasicBlock *MSucc = FuncInfo.MBBMap[LLVMSucc]; FastEmitBranch(MSucc, BI->getDebugLoc()); return true; } // Conditional branches are not handed yet. // Halt "fast" selection and bail. return false; } case Instruction::Unreachable: // Nothing to emit. return true; case Instruction::Alloca: // FunctionLowering has the static-sized case covered. if (FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(I))) return true; // Dynamic-sized alloca is not handled yet. return false; case Instruction::Call: return SelectCall(I); case Instruction::BitCast: return SelectBitCast(I); case Instruction::FPToSI: return SelectCast(I, ISD::FP_TO_SINT); case Instruction::ZExt: return SelectCast(I, ISD::ZERO_EXTEND); case Instruction::SExt: return SelectCast(I, ISD::SIGN_EXTEND); case Instruction::Trunc: return SelectCast(I, ISD::TRUNCATE); case Instruction::SIToFP: return SelectCast(I, ISD::SINT_TO_FP); case Instruction::IntToPtr: // Deliberate fall-through. case Instruction::PtrToInt: { EVT SrcVT = TLI.getValueType(I->getOperand(0)->getType()); EVT DstVT = TLI.getValueType(I->getType()); if (DstVT.bitsGT(SrcVT)) return SelectCast(I, ISD::ZERO_EXTEND); if (DstVT.bitsLT(SrcVT)) return SelectCast(I, ISD::TRUNCATE); unsigned Reg = getRegForValue(I->getOperand(0)); if (Reg == 0) return false; UpdateValueMap(I, Reg); return true; } case Instruction::PHI: llvm_unreachable("FastISel shouldn't visit PHI nodes!"); default: // Unhandled instruction. Halt "fast" selection and bail. return false; } }
bool FastISel::SelectCall(const User *I) { const Function *F = cast<CallInst>(I)->getCalledFunction(); if (!F) return false; // Handle selected intrinsic function calls. unsigned IID = F->getIntrinsicID(); switch (IID) { default: break; case Intrinsic::dbg_declare: { const DbgDeclareInst *DI = cast<DbgDeclareInst>(I); if (!DIVariable(DI->getVariable()).Verify() || !FuncInfo.MF->getMMI().hasDebugInfo()) return true; const Value *Address = DI->getAddress(); if (!Address || isa<UndefValue>(Address) || isa<AllocaInst>(Address)) return true; unsigned Reg = 0; unsigned Offset = 0; if (const Argument *Arg = dyn_cast<Argument>(Address)) { if (Arg->hasByValAttr()) { // Byval arguments' frame index is recorded during argument lowering. // Use this info directly. Offset = FuncInfo.getByValArgumentFrameIndex(Arg); if (Offset) Reg = TRI.getFrameRegister(*FuncInfo.MF); } } if (!Reg) Reg = getRegForValue(Address); if (Reg) BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::DBG_VALUE)) .addReg(Reg, RegState::Debug).addImm(Offset) .addMetadata(DI->getVariable()); return true; } case Intrinsic::dbg_value: { // This form of DBG_VALUE is target-independent. const DbgValueInst *DI = cast<DbgValueInst>(I); const TargetInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE); const Value *V = DI->getValue(); if (!V) { // Currently the optimizer can produce this; insert an undef to // help debugging. Probably the optimizer should not do this. BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II) .addReg(0U).addImm(DI->getOffset()) .addMetadata(DI->getVariable()); } else if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II) .addImm(CI->getZExtValue()).addImm(DI->getOffset()) .addMetadata(DI->getVariable()); } else if (const ConstantFP *CF = dyn_cast<ConstantFP>(V)) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II) .addFPImm(CF).addImm(DI->getOffset()) .addMetadata(DI->getVariable()); } else if (unsigned Reg = lookUpRegForValue(V)) { BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II) .addReg(Reg, RegState::Debug).addImm(DI->getOffset()) .addMetadata(DI->getVariable()); } else { // We can't yet handle anything else here because it would require // generating code, thus altering codegen because of debug info. DEBUG(dbgs() << "Dropping debug info for " << DI); } return true; } case Intrinsic::eh_exception: { EVT VT = TLI.getValueType(I->getType()); switch (TLI.getOperationAction(ISD::EXCEPTIONADDR, VT)) { default: break; case TargetLowering::Expand: { assert(FuncInfo.MBB->isLandingPad() && "Call to eh.exception not in landing pad!"); unsigned Reg = TLI.getExceptionAddressRegister(); const TargetRegisterClass *RC = TLI.getRegClassFor(VT); unsigned ResultReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY), ResultReg).addReg(Reg); UpdateValueMap(I, ResultReg); return true; } } break; } case Intrinsic::eh_selector: { EVT VT = TLI.getValueType(I->getType()); switch (TLI.getOperationAction(ISD::EHSELECTION, VT)) { default: break; case TargetLowering::Expand: { if (FuncInfo.MBB->isLandingPad()) AddCatchInfo(*cast<CallInst>(I), &FuncInfo.MF->getMMI(), FuncInfo.MBB); else { #ifndef NDEBUG FuncInfo.CatchInfoLost.insert(cast<CallInst>(I)); #endif // FIXME: Mark exception selector register as live in. Hack for PR1508. unsigned Reg = TLI.getExceptionSelectorRegister(); if (Reg) FuncInfo.MBB->addLiveIn(Reg); } unsigned Reg = TLI.getExceptionSelectorRegister(); EVT SrcVT = TLI.getPointerTy(); const TargetRegisterClass *RC = TLI.getRegClassFor(SrcVT); unsigned ResultReg = createResultReg(RC); BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY), ResultReg).addReg(Reg); bool ResultRegIsKill = hasTrivialKill(I); // Cast the register to the type of the selector. if (SrcVT.bitsGT(MVT::i32)) ResultReg = FastEmit_r(SrcVT.getSimpleVT(), MVT::i32, ISD::TRUNCATE, ResultReg, ResultRegIsKill); else if (SrcVT.bitsLT(MVT::i32)) ResultReg = FastEmit_r(SrcVT.getSimpleVT(), MVT::i32, ISD::SIGN_EXTEND, ResultReg, ResultRegIsKill); if (ResultReg == 0) // Unhandled operand. Halt "fast" selection and bail. return false; UpdateValueMap(I, ResultReg); return true; } } break; } } // An arbitrary call. Bail. return false; }
SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset(SelectionDAG &DAG, SDLoc dl, SDValue Chain, SDValue Dst, SDValue Src, SDValue Size, unsigned Align, bool isVolatile, MachinePointerInfo DstPtrInfo) const { ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); // If to a segment-relative address space, use the default lowering. if (DstPtrInfo.getAddrSpace() >= 256) return SDValue(); // If not DWORD aligned or size is more than the threshold, call the library. // The libc version is likely to be faster for these cases. It can use the // address value and run time information about the CPU. if ((Align & 3) != 0 || !ConstantSize || ConstantSize->getZExtValue() > Subtarget->getMaxInlineSizeThreshold()) { // Check to see if there is a specialized entry-point for memory zeroing. ConstantSDNode *V = dyn_cast<ConstantSDNode>(Src); if (const char *bzeroEntry = V && V->isNullValue() ? Subtarget->getBZeroEntry() : nullptr) { EVT IntPtr = TLI.getPointerTy(); Type *IntPtrTy = getDataLayout()->getIntPtrType(*DAG.getContext()); TargetLowering::ArgListTy Args; TargetLowering::ArgListEntry Entry; Entry.Node = Dst; Entry.Ty = IntPtrTy; Args.push_back(Entry); Entry.Node = Size; Args.push_back(Entry); TargetLowering::CallLoweringInfo CLI(DAG); CLI.setDebugLoc(dl).setChain(Chain) .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()), DAG.getExternalSymbol(bzeroEntry, IntPtr), &Args, 0) .setDiscardResult(); std::pair<SDValue,SDValue> CallResult = TLI.LowerCallTo(CLI); return CallResult.second; } // Otherwise have the target-independent code call memset. return SDValue(); } uint64_t SizeVal = ConstantSize->getZExtValue(); SDValue InFlag; EVT AVT; SDValue Count; ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Src); unsigned BytesLeft = 0; bool TwoRepStos = false; if (ValC) { unsigned ValReg; uint64_t Val = ValC->getZExtValue() & 255; // If the value is a constant, then we can potentially use larger sets. switch (Align & 3) { case 2: // WORD aligned AVT = MVT::i16; ValReg = X86::AX; Val = (Val << 8) | Val; break; case 0: // DWORD aligned AVT = MVT::i32; ValReg = X86::EAX; Val = (Val << 8) | Val; Val = (Val << 16) | Val; if (Subtarget->is64Bit() && ((Align & 0x7) == 0)) { // QWORD aligned AVT = MVT::i64; ValReg = X86::RAX; Val = (Val << 32) | Val; } break; default: // Byte aligned AVT = MVT::i8; ValReg = X86::AL; Count = DAG.getIntPtrConstant(SizeVal); break; } if (AVT.bitsGT(MVT::i8)) { unsigned UBytes = AVT.getSizeInBits() / 8; Count = DAG.getIntPtrConstant(SizeVal / UBytes); BytesLeft = SizeVal % UBytes; } Chain = DAG.getCopyToReg(Chain, dl, ValReg, DAG.getConstant(Val, AVT), InFlag); InFlag = Chain.getValue(1); } else { AVT = MVT::i8; Count = DAG.getIntPtrConstant(SizeVal); Chain = DAG.getCopyToReg(Chain, dl, X86::AL, Src, InFlag); InFlag = Chain.getValue(1); } Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RCX : X86::ECX, Count, InFlag); InFlag = Chain.getValue(1); Chain = DAG.getCopyToReg(Chain, dl, Subtarget->is64Bit() ? X86::RDI : X86::EDI, Dst, InFlag); InFlag = Chain.getValue(1); SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue); SDValue Ops[] = { Chain, DAG.getValueType(AVT), InFlag }; Chain = DAG.getNode(X86ISD::REP_STOS, dl, Tys, Ops); if (TwoRepStos) { InFlag = Chain.getValue(1); Count = Size; EVT CVT = Count.getValueType(); SDValue Left = DAG.getNode(ISD::AND, dl, CVT, Count, DAG.getConstant((AVT == MVT::i64) ? 7 : 3, CVT)); Chain = DAG.getCopyToReg(Chain, dl, (CVT == MVT::i64) ? X86::RCX : X86::ECX, Left, InFlag); InFlag = Chain.getValue(1); Tys = DAG.getVTList(MVT::Other, MVT::Glue); SDValue Ops[] = { Chain, DAG.getValueType(MVT::i8), InFlag }; Chain = DAG.getNode(X86ISD::REP_STOS, dl, Tys, Ops); } else if (BytesLeft) { // Handle the last 1 - 7 bytes. unsigned Offset = SizeVal - BytesLeft; EVT AddrVT = Dst.getValueType(); EVT SizeVT = Size.getValueType(); Chain = DAG.getMemset(Chain, dl, DAG.getNode(ISD::ADD, dl, AddrVT, Dst, DAG.getConstant(Offset, AddrVT)), Src, DAG.getConstant(BytesLeft, SizeVT), Align, isVolatile, DstPtrInfo.getWithOffset(Offset)); } // TODO: Use a Tokenfactor, as in memcpy, instead of a single chain. return Chain; }
bool FastISel::SelectCall(User *I) { Function *F = cast<CallInst>(I)->getCalledFunction(); if (!F) return false; unsigned IID = F->getIntrinsicID(); switch (IID) { default: break; case Intrinsic::dbg_stoppoint: case Intrinsic::dbg_region_start: case Intrinsic::dbg_region_end: case Intrinsic::dbg_func_start: // FIXME - Remove this instructions once the dust settles. return true; case Intrinsic::dbg_declare: { DbgDeclareInst *DI = cast<DbgDeclareInst>(I); if (!isValidDebugInfoIntrinsic(*DI, CodeGenOpt::None) || !DW || !DW->ShouldEmitDwarfDebug()) return true; Value *Address = DI->getAddress(); if (BitCastInst *BCI = dyn_cast<BitCastInst>(Address)) Address = BCI->getOperand(0); AllocaInst *AI = dyn_cast<AllocaInst>(Address); // Don't handle byval struct arguments or VLAs, for example. if (!AI) break; DenseMap<const AllocaInst*, int>::iterator SI = StaticAllocaMap.find(AI); if (SI == StaticAllocaMap.end()) break; // VLAs. int FI = SI->second; if (MMI) { MetadataContext &TheMetadata = DI->getParent()->getContext().getMetadata(); unsigned MDDbgKind = TheMetadata.getMDKind("dbg"); MDNode *Dbg = TheMetadata.getMD(MDDbgKind, DI); MMI->setVariableDbgInfo(DI->getVariable(), FI, Dbg); } return true; } case Intrinsic::eh_exception: { EVT VT = TLI.getValueType(I->getType()); switch (TLI.getOperationAction(ISD::EXCEPTIONADDR, VT)) { default: break; case TargetLowering::Expand: { assert(MBB->isLandingPad() && "Call to eh.exception not in landing pad!"); unsigned Reg = TLI.getExceptionAddressRegister(); const TargetRegisterClass *RC = TLI.getRegClassFor(VT); unsigned ResultReg = createResultReg(RC); bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg, Reg, RC, RC); assert(InsertedCopy && "Can't copy address registers!"); InsertedCopy = InsertedCopy; UpdateValueMap(I, ResultReg); return true; } } break; } case Intrinsic::eh_selector: { EVT VT = TLI.getValueType(I->getType()); switch (TLI.getOperationAction(ISD::EHSELECTION, VT)) { default: break; case TargetLowering::Expand: { if (MMI) { if (MBB->isLandingPad()) AddCatchInfo(*cast<CallInst>(I), MMI, MBB); else { #ifndef NDEBUG CatchInfoLost.insert(cast<CallInst>(I)); #endif // FIXME: Mark exception selector register as live in. Hack for PR1508. unsigned Reg = TLI.getExceptionSelectorRegister(); if (Reg) MBB->addLiveIn(Reg); } unsigned Reg = TLI.getExceptionSelectorRegister(); EVT SrcVT = TLI.getPointerTy(); const TargetRegisterClass *RC = TLI.getRegClassFor(SrcVT); unsigned ResultReg = createResultReg(RC); bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg, Reg, RC, RC); assert(InsertedCopy && "Can't copy address registers!"); InsertedCopy = InsertedCopy; // Cast the register to the type of the selector. if (SrcVT.bitsGT(MVT::i32)) ResultReg = FastEmit_r(SrcVT.getSimpleVT(), MVT::i32, ISD::TRUNCATE, ResultReg); else if (SrcVT.bitsLT(MVT::i32)) ResultReg = FastEmit_r(SrcVT.getSimpleVT(), MVT::i32, ISD::SIGN_EXTEND, ResultReg); if (ResultReg == 0) // Unhandled operand. Halt "fast" selection and bail. return false; UpdateValueMap(I, ResultReg); } else { unsigned ResultReg = getRegForValue(Constant::getNullValue(I->getType())); UpdateValueMap(I, ResultReg); } return true; } } break; } } return false; }
bool FastISel::SelectCall(const User *I) { const Function *F = cast<CallInst>(I)->getCalledFunction(); if (!F) return false; // Handle selected intrinsic function calls. unsigned IID = F->getIntrinsicID(); switch (IID) { default: break; case Intrinsic::dbg_declare: { const DbgDeclareInst *DI = cast<DbgDeclareInst>(I); if (!DIDescriptor::ValidDebugInfo(DI->getVariable(), CodeGenOpt::None) || !MF.getMMI().hasDebugInfo()) return true; const Value *Address = DI->getAddress(); if (!Address) return true; if (isa<UndefValue>(Address)) return true; const AllocaInst *AI = dyn_cast<AllocaInst>(Address); // Don't handle byval struct arguments or VLAs, for example. if (!AI) break; DenseMap<const AllocaInst*, int>::iterator SI = StaticAllocaMap.find(AI); if (SI == StaticAllocaMap.end()) break; // VLAs. int FI = SI->second; if (!DI->getDebugLoc().isUnknown()) MF.getMMI().setVariableDbgInfo(DI->getVariable(), FI, DI->getDebugLoc()); // Building the map above is target independent. Generating DBG_VALUE // inline is target dependent; do this now. (void)TargetSelectInstruction(cast<Instruction>(I)); return true; } case Intrinsic::dbg_value: { // This form of DBG_VALUE is target-independent. const DbgValueInst *DI = cast<DbgValueInst>(I); const TargetInstrDesc &II = TII.get(TargetOpcode::DBG_VALUE); const Value *V = DI->getValue(); if (!V) { // Currently the optimizer can produce this; insert an undef to // help debugging. Probably the optimizer should not do this. BuildMI(MBB, DL, II).addReg(0U).addImm(DI->getOffset()). addMetadata(DI->getVariable()); } else if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) { BuildMI(MBB, DL, II).addImm(CI->getZExtValue()).addImm(DI->getOffset()). addMetadata(DI->getVariable()); } else if (const ConstantFP *CF = dyn_cast<ConstantFP>(V)) { BuildMI(MBB, DL, II).addFPImm(CF).addImm(DI->getOffset()). addMetadata(DI->getVariable()); } else if (unsigned Reg = lookUpRegForValue(V)) { BuildMI(MBB, DL, II).addReg(Reg, RegState::Debug).addImm(DI->getOffset()). addMetadata(DI->getVariable()); } else { // We can't yet handle anything else here because it would require // generating code, thus altering codegen because of debug info. // Insert an undef so we can see what we dropped. BuildMI(MBB, DL, II).addReg(0U).addImm(DI->getOffset()). addMetadata(DI->getVariable()); } return true; } case Intrinsic::eh_exception: { EVT VT = TLI.getValueType(I->getType()); switch (TLI.getOperationAction(ISD::EXCEPTIONADDR, VT)) { default: break; case TargetLowering::Expand: { assert(MBB->isLandingPad() && "Call to eh.exception not in landing pad!"); unsigned Reg = TLI.getExceptionAddressRegister(); const TargetRegisterClass *RC = TLI.getRegClassFor(VT); unsigned ResultReg = createResultReg(RC); bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg, Reg, RC, RC); assert(InsertedCopy && "Can't copy address registers!"); InsertedCopy = InsertedCopy; UpdateValueMap(I, ResultReg); return true; } } break; } case Intrinsic::eh_selector: { EVT VT = TLI.getValueType(I->getType()); switch (TLI.getOperationAction(ISD::EHSELECTION, VT)) { default: break; case TargetLowering::Expand: { if (MBB->isLandingPad()) AddCatchInfo(*cast<CallInst>(I), &MF.getMMI(), MBB); else { #ifndef NDEBUG CatchInfoLost.insert(cast<CallInst>(I)); #endif // FIXME: Mark exception selector register as live in. Hack for PR1508. unsigned Reg = TLI.getExceptionSelectorRegister(); if (Reg) MBB->addLiveIn(Reg); } unsigned Reg = TLI.getExceptionSelectorRegister(); EVT SrcVT = TLI.getPointerTy(); const TargetRegisterClass *RC = TLI.getRegClassFor(SrcVT); unsigned ResultReg = createResultReg(RC); bool InsertedCopy = TII.copyRegToReg(*MBB, MBB->end(), ResultReg, Reg, RC, RC); assert(InsertedCopy && "Can't copy address registers!"); InsertedCopy = InsertedCopy; // Cast the register to the type of the selector. if (SrcVT.bitsGT(MVT::i32)) ResultReg = FastEmit_r(SrcVT.getSimpleVT(), MVT::i32, ISD::TRUNCATE, ResultReg); else if (SrcVT.bitsLT(MVT::i32)) ResultReg = FastEmit_r(SrcVT.getSimpleVT(), MVT::i32, ISD::SIGN_EXTEND, ResultReg); if (ResultReg == 0) // Unhandled operand. Halt "fast" selection and bail. return false; UpdateValueMap(I, ResultReg); return true; } } break; } } // An arbitrary call. Bail. return false; }
SDValue X86SelectionDAGInfo::EmitTargetCodeForMemset( SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Val, SDValue Size, unsigned Align, bool isVolatile, MachinePointerInfo DstPtrInfo) const { ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size); const X86Subtarget &Subtarget = DAG.getMachineFunction().getSubtarget<X86Subtarget>(); #ifndef NDEBUG // If the base register might conflict with our physical registers, bail out. const MCPhysReg ClobberSet[] = {X86::RCX, X86::RAX, X86::RDI, X86::ECX, X86::EAX, X86::EDI}; assert(!isBaseRegConflictPossible(DAG, ClobberSet)); #endif // If to a segment-relative address space, use the default lowering. if (DstPtrInfo.getAddrSpace() >= 256) return SDValue(); // If not DWORD aligned or size is more than the threshold, call the library. // The libc version is likely to be faster for these cases. It can use the // address value and run time information about the CPU. if ((Align & 3) != 0 || !ConstantSize || ConstantSize->getZExtValue() > Subtarget.getMaxInlineSizeThreshold()) { // Check to see if there is a specialized entry-point for memory zeroing. ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Val); if (const char *bzeroName = (ValC && ValC->isNullValue()) ? DAG.getTargetLoweringInfo().getLibcallName(RTLIB::BZERO) : nullptr) { const TargetLowering &TLI = DAG.getTargetLoweringInfo(); EVT IntPtr = TLI.getPointerTy(DAG.getDataLayout()); Type *IntPtrTy = DAG.getDataLayout().getIntPtrType(*DAG.getContext()); TargetLowering::ArgListTy Args; TargetLowering::ArgListEntry Entry; Entry.Node = Dst; Entry.Ty = IntPtrTy; Args.push_back(Entry); Entry.Node = Size; Args.push_back(Entry); TargetLowering::CallLoweringInfo CLI(DAG); CLI.setDebugLoc(dl) .setChain(Chain) .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()), DAG.getExternalSymbol(bzeroName, IntPtr), std::move(Args)) .setDiscardResult(); std::pair<SDValue,SDValue> CallResult = TLI.LowerCallTo(CLI); return CallResult.second; } // Otherwise have the target-independent code call memset. return SDValue(); } uint64_t SizeVal = ConstantSize->getZExtValue(); SDValue InFlag; EVT AVT; SDValue Count; ConstantSDNode *ValC = dyn_cast<ConstantSDNode>(Val); unsigned BytesLeft = 0; if (ValC) { unsigned ValReg; uint64_t Val = ValC->getZExtValue() & 255; // If the value is a constant, then we can potentially use larger sets. switch (Align & 3) { case 2: // WORD aligned AVT = MVT::i16; ValReg = X86::AX; Val = (Val << 8) | Val; break; case 0: // DWORD aligned AVT = MVT::i32; ValReg = X86::EAX; Val = (Val << 8) | Val; Val = (Val << 16) | Val; if (Subtarget.is64Bit() && ((Align & 0x7) == 0)) { // QWORD aligned AVT = MVT::i64; ValReg = X86::RAX; Val = (Val << 32) | Val; } break; default: // Byte aligned AVT = MVT::i8; ValReg = X86::AL; Count = DAG.getIntPtrConstant(SizeVal, dl); break; } if (AVT.bitsGT(MVT::i8)) { unsigned UBytes = AVT.getSizeInBits() / 8; Count = DAG.getIntPtrConstant(SizeVal / UBytes, dl); BytesLeft = SizeVal % UBytes; } Chain = DAG.getCopyToReg(Chain, dl, ValReg, DAG.getConstant(Val, dl, AVT), InFlag); InFlag = Chain.getValue(1); } else { AVT = MVT::i8; Count = DAG.getIntPtrConstant(SizeVal, dl); Chain = DAG.getCopyToReg(Chain, dl, X86::AL, Val, InFlag); InFlag = Chain.getValue(1); } bool Use64BitRegs = Subtarget.isTarget64BitLP64(); Chain = DAG.getCopyToReg(Chain, dl, Use64BitRegs ? X86::RCX : X86::ECX, Count, InFlag); InFlag = Chain.getValue(1); Chain = DAG.getCopyToReg(Chain, dl, Use64BitRegs ? X86::RDI : X86::EDI, Dst, InFlag); InFlag = Chain.getValue(1); SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue); SDValue Ops[] = { Chain, DAG.getValueType(AVT), InFlag }; Chain = DAG.getNode(X86ISD::REP_STOS, dl, Tys, Ops); if (BytesLeft) { // Handle the last 1 - 7 bytes. unsigned Offset = SizeVal - BytesLeft; EVT AddrVT = Dst.getValueType(); EVT SizeVT = Size.getValueType(); Chain = DAG.getMemset(Chain, dl, DAG.getNode(ISD::ADD, dl, AddrVT, Dst, DAG.getConstant(Offset, dl, AddrVT)), Val, DAG.getConstant(BytesLeft, dl, SizeVT), Align, isVolatile, false, DstPtrInfo.getWithOffset(Offset)); } // TODO: Use a Tokenfactor, as in memcpy, instead of a single chain. return Chain; }