C++ ArgListTy::push_back方法代码示例

SDValue ARM64SelectionDAGInfo::EmitTargetCodeForMemset(
    SelectionDAG &DAG, SDLoc dl, SDValue Chain, SDValue Dst, SDValue Src,
    SDValue Size, unsigned Align, bool isVolatile,
    MachinePointerInfo DstPtrInfo) const {
  // Check to see if there is a specialized entry-point for memory zeroing.
  ConstantSDNode *V = dyn_cast<ConstantSDNode>(Src);
  ConstantSDNode *SizeValue = dyn_cast<ConstantSDNode>(Size);
  const char *bzeroEntry =
      (V && V->isNullValue()) ? Subtarget->getBZeroEntry() : 0;
  // For small size (< 256), it is not beneficial to use bzero
  // instead of memset.
  if (bzeroEntry && (!SizeValue || SizeValue->getZExtValue() > 256)) {
    const ARM64TargetLowering &TLI = *static_cast<const ARM64TargetLowering *>(
                                          DAG.getTarget().getTargetLowering());

    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(
        Chain, Type::getVoidTy(*DAG.getContext()), false, false, false, false,
        0, CallingConv::C, /*isTailCall=*/false,
        /*doesNotRet=*/false, /*isReturnValueUsed=*/false,
        DAG.getExternalSymbol(bzeroEntry, IntPtr), Args, DAG, dl);
    std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
    return CallResult.second;
  }
  return SDValue();
}

SDValue XCoreSelectionDAGInfo::
EmitTargetCodeForMemcpy(SelectionDAG &DAG, SDLoc dl, SDValue Chain,
                        SDValue Dst, SDValue Src, SDValue Size, unsigned Align,
                        bool isVolatile, bool AlwaysInline,
                        MachinePointerInfo DstPtrInfo,
                        MachinePointerInfo SrcPtrInfo) const
{
  unsigned SizeBitWidth = Size.getValueType().getSizeInBits();
  // Call __memcpy_4 if the src, dst and size are all 4 byte aligned.
  if (!AlwaysInline && (Align & 3) == 0 &&
      DAG.MaskedValueIsZero(Size, APInt(SizeBitWidth, 3))) {
    const TargetLowering &TLI = *DAG.getTarget().getTargetLowering();
    TargetLowering::ArgListTy Args;
    TargetLowering::ArgListEntry Entry;
    Entry.Ty = TLI.getDataLayout()->getIntPtrType(*DAG.getContext());
    Entry.Node = Dst; Args.push_back(Entry);
    Entry.Node = Src; Args.push_back(Entry);
    Entry.Node = Size; Args.push_back(Entry);

    TargetLowering::CallLoweringInfo CLI(DAG);
    CLI.setDebugLoc(dl).setChain(Chain)
      .setCallee(TLI.getLibcallCallingConv(RTLIB::MEMCPY),
                 Type::getVoidTy(*DAG.getContext()),
                 DAG.getExternalSymbol("__memcpy_4", TLI.getPointerTy()),
                 &Args, 0)
      .setDiscardResult();

    std::pair<SDValue,SDValue> CallResult = TLI.LowerCallTo(CLI);
    return CallResult.second;
  }

  // Otherwise have the target-independent code call memcpy.
  return SDValue();
}

// Adjust parameters for memset, EABI uses format (ptr, size, value),
// GNU library uses (ptr, value, size)
// See RTABI section 4.3.4
SDValue ARMSelectionDAGInfo::
EmitTargetCodeForMemset(SelectionDAG &DAG, SDLoc dl,
                        SDValue Chain, SDValue Dst,
                        SDValue Src, SDValue Size,
                        unsigned Align, bool isVolatile,
                        MachinePointerInfo DstPtrInfo) const {
  // Use default for non AAPCS (or Darwin) subtargets
  if (!Subtarget->isAAPCS_ABI() || Subtarget->isTargetDarwin())
    return SDValue();

  const ARMTargetLowering &TLI =
    *static_cast<const ARMTargetLowering*>(DAG.getTarget().getTargetLowering());
  TargetLowering::ArgListTy Args;
  TargetLowering::ArgListEntry Entry;

  // First argument: data pointer
  Type *IntPtrTy = TLI.getDataLayout()->getIntPtrType(*DAG.getContext());
  Entry.Node = Dst;
  Entry.Ty = IntPtrTy;
  Args.push_back(Entry);

  // Second argument: buffer size
  Entry.Node = Size;
  Entry.Ty = IntPtrTy;
  Entry.isSExt = false;
  Args.push_back(Entry);

  // Extend or truncate the argument to be an i32 value for the call.
  if (Src.getValueType().bitsGT(MVT::i32))
    Src = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Src);
  else
    Src = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, Src);

  // Third argument: value to fill
  Entry.Node = Src;
  Entry.Ty = Type::getInt32Ty(*DAG.getContext());
  Entry.isSExt = true;
  Args.push_back(Entry);

  // Emit __eabi_memset call
  TargetLowering::CallLoweringInfo CLI(Chain,
                    Type::getVoidTy(*DAG.getContext()), // return type
                    false, // return sign ext
                    false, // return zero ext
                    false, // is var arg
                    false, // is in regs
                    0,     // number of fixed arguments
                    TLI.getLibcallCallingConv(RTLIB::MEMSET), // call conv
                    false, // is tail call
                    false, // does not return
                    false, // is return val used
                    DAG.getExternalSymbol(TLI.getLibcallName(RTLIB::MEMSET),
                                          TLI.getPointerTy()), // callee
                    Args, DAG, dl);
  std::pair<SDValue,SDValue> CallResult =
    TLI.LowerCallTo(CLI);

  return CallResult.second;
}

SDValue HexagonSelectionDAGInfo::EmitTargetCodeForMemcpy(
    SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
    SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline,
    MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
  ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
  if (AlwaysInline || (Align & 0x3) != 0 || !ConstantSize)
    return SDValue();

  uint64_t SizeVal = ConstantSize->getZExtValue();
  if (SizeVal < 32 || (SizeVal % 8) != 0)
    return SDValue();

  // Special case aligned memcpys with size >= 32 bytes and a multiple of 8.
  //
  const TargetLowering &TLI = *DAG.getSubtarget().getTargetLowering();
  TargetLowering::ArgListTy Args;
  TargetLowering::ArgListEntry Entry;
  Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
  Entry.Node = Dst;
  Args.push_back(Entry);
  Entry.Node = Src;
  Args.push_back(Entry);
  Entry.Node = Size;
  Args.push_back(Entry);

  const char *SpecialMemcpyName =
      "__hexagon_memcpy_likely_aligned_min32bytes_mult8bytes";

  TargetLowering::CallLoweringInfo CLI(DAG);
  CLI.setDebugLoc(dl)
      .setChain(Chain)
      .setCallee(TLI.getLibcallCallingConv(RTLIB::MEMCPY),
                 Type::getVoidTy(*DAG.getContext()),
                 DAG.getTargetExternalSymbol(
                     SpecialMemcpyName, TLI.getPointerTy(DAG.getDataLayout())),
                 std::move(Args))
      .setDiscardResult();

  std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
  return CallResult.second;
}

// Emit, if possible, a specialized version of the given Libcall. Typically this
// means selecting the appropriately aligned version, but we also convert memset
// of 0 into memclr.
SDValue ARMSelectionDAGInfo::EmitSpecializedLibcall(
    SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
    SDValue Size, unsigned Align, RTLIB::Libcall LC) const {
  const ARMSubtarget &Subtarget =
      DAG.getMachineFunction().getSubtarget<ARMSubtarget>();
  const ARMTargetLowering *TLI = Subtarget.getTargetLowering();

  // Only use a specialized AEABI function if the default version of this
  // Libcall is an AEABI function.
  if (std::strncmp(TLI->getLibcallName(LC), "__aeabi", 7) != 0)
    return SDValue();

  // Translate RTLIB::Libcall to AEABILibcall. We only do this in order to be
  // able to translate memset to memclr and use the value to index the function
  // name array.
  enum {
    AEABI_MEMCPY = 0,
    AEABI_MEMMOVE,
    AEABI_MEMSET,
    AEABI_MEMCLR
  } AEABILibcall;
  switch (LC) {
  case RTLIB::MEMCPY:
    AEABILibcall = AEABI_MEMCPY;
    break;
  case RTLIB::MEMMOVE:
    AEABILibcall = AEABI_MEMMOVE;
    break;
  case RTLIB::MEMSET:
    AEABILibcall = AEABI_MEMSET;
    if (ConstantSDNode *ConstantSrc = dyn_cast<ConstantSDNode>(Src))
      if (ConstantSrc->getZExtValue() == 0)
        AEABILibcall = AEABI_MEMCLR;
    break;
  default:
    return SDValue();
  }

  // Choose the most-aligned libcall variant that we can
  enum {
    ALIGN1 = 0,
    ALIGN4,
    ALIGN8
  } AlignVariant;
  if ((Align & 7) == 0)
    AlignVariant = ALIGN8;
  else if ((Align & 3) == 0)
    AlignVariant = ALIGN4;
  else
    AlignVariant = ALIGN1;

  TargetLowering::ArgListTy Args;
  TargetLowering::ArgListEntry Entry;
  Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
  Entry.Node = Dst;
  Args.push_back(Entry);
  if (AEABILibcall == AEABI_MEMCLR) {
    Entry.Node = Size;
    Args.push_back(Entry);
  } else if (AEABILibcall == AEABI_MEMSET) {
    // Adjust parameters for memset, EABI uses format (ptr, size, value),
    // GNU library uses (ptr, value, size)
    // See RTABI section 4.3.4
    Entry.Node = Size;
    Args.push_back(Entry);

    // Extend or truncate the argument to be an i32 value for the call.
    if (Src.getValueType().bitsGT(MVT::i32))
      Src = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, Src);
    else if (Src.getValueType().bitsLT(MVT::i32))
      Src = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::i32, Src);

    Entry.Node = Src;
    Entry.Ty = Type::getInt32Ty(*DAG.getContext());
    Entry.IsSExt = false;
    Args.push_back(Entry);
  } else {
    Entry.Node = Src;
    Args.push_back(Entry);

    Entry.Node = Size;
    Args.push_back(Entry);
  }

  char const *FunctionNames[4][3] = {
    { "__aeabi_memcpy",  "__aeabi_memcpy4",  "__aeabi_memcpy8"  },
    { "__aeabi_memmove", "__aeabi_memmove4", "__aeabi_memmove8" },
    { "__aeabi_memset",  "__aeabi_memset4",  "__aeabi_memset8"  },
    { "__aeabi_memclr",  "__aeabi_memclr4",  "__aeabi_memclr8"  }
  };
  TargetLowering::CallLoweringInfo CLI(DAG);
  CLI.setDebugLoc(dl)
      .setChain(Chain)
      .setLibCallee(
          TLI->getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()),
          DAG.getExternalSymbol(FunctionNames[AEABILibcall][AlignVariant],
                                TLI->getPointerTy(DAG.getDataLayout())),
//.........这里部分代码省略.........

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);
  }
//.........这里部分代码省略.........

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);
//.........这里部分代码省略.........