lib/Target/X86/X86SelectionDAGInfo.cpp - platform/external/llvm - Git at Google

 //===-- X86SelectionDAGInfo.cpp - X86 SelectionDAG Info -------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the X86SelectionDAGInfo class.
 //
 //===----------------------------------------------------------------------===//

 #include "X86InstrInfo.h"
 #include "X86ISelLowering.h"
 #include "X86RegisterInfo.h"
 #include "X86Subtarget.h"
 #include "X86SelectionDAGInfo.h"
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/Target/TargetLowering.h"

 using namespace llvm;

 #define DEBUG_TYPE "x86-selectiondag-info"

 X86SelectionDAGInfo::X86SelectionDAGInfo(const DataLayout &DL)
     : TargetSelectionDAGInfo(&DL) {}

 X86SelectionDAGInfo::~X86SelectionDAGInfo() {}

 bool X86SelectionDAGInfo::isBaseRegConflictPossible(
     SelectionDAG &DAG, ArrayRef<unsigned> ClobberSet) const {
   // We cannot use TRI->hasBasePointer() until *after* we select all basic
   // blocks.  Legalization may introduce new stack temporaries with large
   // alignment requirements.  Fall back to generic code if there are any
   // dynamic stack adjustments (hopefully rare) and the base pointer would
   // conflict if we had to use it.
   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
   if (!MFI->hasVarSizedObjects() && !MFI->hasInlineAsmWithSPAdjust())
     return false;

   const X86RegisterInfo *TRI = static_cast<const X86RegisterInfo *>(
       DAG.getSubtarget().getRegisterInfo());
   unsigned BaseReg = TRI->getBaseRegister();
   for (unsigned R : ClobberSet)
     if (BaseReg == R)
       return true;
   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);
   const X86Subtarget &Subtarget =
       DAG.getMachineFunction().getSubtarget<X86Subtarget>();

 #ifndef NDEBUG
   // If the base register might conflict with our physical registers, bail out.
   const unsigned 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 *V = dyn_cast<ConstantSDNode>(Src);

     if (const char *bzeroEntry =  V &&
         V->isNullValue() ? Subtarget.getBZeroEntry() : nullptr) {
       EVT IntPtr = DAG.getTargetLoweringInfo().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), std::move(Args),
                    0)
         .setDiscardResult();

       std::pair<SDValue,SDValue> CallResult = DAG.getTargetLoweringInfo().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, false,
                           DstPtrInfo.getWithOffset(Offset));
   }

   // TODO: Use a Tokenfactor, as in memcpy, instead of a single chain.
   return Chain;
 }

 SDValue X86SelectionDAGInfo::EmitTargetCodeForMemcpy(
     SelectionDAG &DAG, SDLoc dl, SDValue Chain, SDValue Dst, SDValue Src,
     SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline,
     MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
   // This requires the copy size to be a constant, preferably
   // within a subtarget-specific limit.
   ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
   const X86Subtarget &Subtarget =
       DAG.getMachineFunction().getSubtarget<X86Subtarget>();
   if (!ConstantSize)
     return SDValue();
   uint64_t SizeVal = ConstantSize->getZExtValue();
   if (!AlwaysInline && SizeVal > Subtarget.getMaxInlineSizeThreshold())
     return SDValue();

   /// If not DWORD aligned, it is more efficient to call the library.  However
   /// if calling the library is not allowed (AlwaysInline), then soldier on as
   /// the code generated here is better than the long load-store sequence we
   /// would otherwise get.
   if (!AlwaysInline && (Align & 3) != 0)
     return SDValue();

   // If to a segment-relative address space, use the default lowering.
   if (DstPtrInfo.getAddrSpace() >= 256 ||
       SrcPtrInfo.getAddrSpace() >= 256)
     return SDValue();

   // If the base register might conflict with our physical registers, bail out.
   const unsigned ClobberSet[] = {X86::RCX, X86::RSI, X86::RDI,
                                  X86::ECX, X86::ESI, X86::EDI};
   if (isBaseRegConflictPossible(DAG, ClobberSet))
     return SDValue();

   MVT AVT;
   if (Align & 1)
     AVT = MVT::i8;
   else if (Align & 2)
     AVT = MVT::i16;
   else if (Align & 4)
     // DWORD aligned
     AVT = MVT::i32;
   else
     // QWORD aligned
     AVT = Subtarget.is64Bit() ? MVT::i64 : MVT::i32;

   unsigned UBytes = AVT.getSizeInBits() / 8;
   unsigned CountVal = SizeVal / UBytes;
   SDValue Count = DAG.getIntPtrConstant(CountVal);
   unsigned BytesLeft = SizeVal % UBytes;

   SDValue InFlag;
   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);
   Chain  = DAG.getCopyToReg(Chain, dl, Subtarget.is64Bit() ? X86::RSI :
                                                               X86::ESI,
                             Src, InFlag);
   InFlag = Chain.getValue(1);

   SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
   SDValue Ops[] = { Chain, DAG.getValueType(AVT), InFlag };
   SDValue RepMovs = DAG.getNode(X86ISD::REP_MOVS, dl, Tys, Ops);

   SmallVector<SDValue, 4> Results;
   Results.push_back(RepMovs);
   if (BytesLeft) {
     // Handle the last 1 - 7 bytes.
     unsigned Offset = SizeVal - BytesLeft;
     EVT DstVT = Dst.getValueType();
     EVT SrcVT = Src.getValueType();
     EVT SizeVT = Size.getValueType();
     Results.push_back(DAG.getMemcpy(Chain, dl,
                                     DAG.getNode(ISD::ADD, dl, DstVT, Dst,
                                                 DAG.getConstant(Offset, DstVT)),
                                     DAG.getNode(ISD::ADD, dl, SrcVT, Src,
                                                 DAG.getConstant(Offset, SrcVT)),
                                     DAG.getConstant(BytesLeft, SizeVT),
                                     Align, isVolatile, AlwaysInline, false,
                                     DstPtrInfo.getWithOffset(Offset),
                                     SrcPtrInfo.getWithOffset(Offset)));
   }

   return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Results);
 }
	//===-- X86SelectionDAGInfo.cpp - X86 SelectionDAG Info -------------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file implements the X86SelectionDAGInfo class.
	//
	//===----------------------------------------------------------------------===//

	#include "X86InstrInfo.h"
	#include "X86ISelLowering.h"
	#include "X86RegisterInfo.h"
	#include "X86Subtarget.h"
	#include "X86SelectionDAGInfo.h"
	#include "llvm/CodeGen/SelectionDAG.h"
	#include "llvm/IR/DerivedTypes.h"
	#include "llvm/Target/TargetLowering.h"

	using namespace llvm;

	#define DEBUG_TYPE "x86-selectiondag-info"

	X86SelectionDAGInfo::X86SelectionDAGInfo(const DataLayout &DL)
	: TargetSelectionDAGInfo(&DL) {}

	X86SelectionDAGInfo::~X86SelectionDAGInfo() {}

	bool X86SelectionDAGInfo::isBaseRegConflictPossible(
	SelectionDAG &DAG, ArrayRef<unsigned> ClobberSet) const {
	// We cannot use TRI->hasBasePointer() until after we select all basic
	// blocks. Legalization may introduce new stack temporaries with large
	// alignment requirements. Fall back to generic code if there are any
	// dynamic stack adjustments (hopefully rare) and the base pointer would
	// conflict if we had to use it.
	MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
	if (!MFI->hasVarSizedObjects() && !MFI->hasInlineAsmWithSPAdjust())
	return false;

	const X86RegisterInfo TRI = static_cast<const X86RegisterInfo >(
	DAG.getSubtarget().getRegisterInfo());
	unsigned BaseReg = TRI->getBaseRegister();
	for (unsigned R : ClobberSet)
	if (BaseReg == R)
	return true;
	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);
	const X86Subtarget &Subtarget =
	DAG.getMachineFunction().getSubtarget<X86Subtarget>();

	#ifndef NDEBUG
	// If the base register might conflict with our physical registers, bail out.
	const unsigned 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 *V = dyn_cast<ConstantSDNode>(Src);

	if (const char *bzeroEntry = V &&
	V->isNullValue() ? Subtarget.getBZeroEntry() : nullptr) {
	EVT IntPtr = DAG.getTargetLoweringInfo().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), std::move(Args),
	0)
	.setDiscardResult();

	std::pair<SDValue,SDValue> CallResult = DAG.getTargetLoweringInfo().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, false,
	DstPtrInfo.getWithOffset(Offset));
	}

	// TODO: Use a Tokenfactor, as in memcpy, instead of a single chain.
	return Chain;
	}

	SDValue X86SelectionDAGInfo::EmitTargetCodeForMemcpy(
	SelectionDAG &DAG, SDLoc dl, SDValue Chain, SDValue Dst, SDValue Src,
	SDValue Size, unsigned Align, bool isVolatile, bool AlwaysInline,
	MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo) const {
	// This requires the copy size to be a constant, preferably
	// within a subtarget-specific limit.
	ConstantSDNode *ConstantSize = dyn_cast<ConstantSDNode>(Size);
	const X86Subtarget &Subtarget =
	DAG.getMachineFunction().getSubtarget<X86Subtarget>();
	if (!ConstantSize)
	return SDValue();
	uint64_t SizeVal = ConstantSize->getZExtValue();
	if (!AlwaysInline && SizeVal > Subtarget.getMaxInlineSizeThreshold())
	return SDValue();

	/// If not DWORD aligned, it is more efficient to call the library. However
	/// if calling the library is not allowed (AlwaysInline), then soldier on as
	/// the code generated here is better than the long load-store sequence we
	/// would otherwise get.
	if (!AlwaysInline && (Align & 3) != 0)
	return SDValue();

	// If to a segment-relative address space, use the default lowering.
	if (DstPtrInfo.getAddrSpace() >= 256 \|\|
	SrcPtrInfo.getAddrSpace() >= 256)
	return SDValue();

	// If the base register might conflict with our physical registers, bail out.
	const unsigned ClobberSet[] = {X86::RCX, X86::RSI, X86::RDI,
	X86::ECX, X86::ESI, X86::EDI};
	if (isBaseRegConflictPossible(DAG, ClobberSet))
	return SDValue();

	MVT AVT;
	if (Align & 1)
	AVT = MVT::i8;
	else if (Align & 2)
	AVT = MVT::i16;
	else if (Align & 4)
	// DWORD aligned
	AVT = MVT::i32;
	else
	// QWORD aligned
	AVT = Subtarget.is64Bit() ? MVT::i64 : MVT::i32;

	unsigned UBytes = AVT.getSizeInBits() / 8;
	unsigned CountVal = SizeVal / UBytes;
	SDValue Count = DAG.getIntPtrConstant(CountVal);
	unsigned BytesLeft = SizeVal % UBytes;

	SDValue InFlag;
	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);
	Chain = DAG.getCopyToReg(Chain, dl, Subtarget.is64Bit() ? X86::RSI :
	X86::ESI,
	Src, InFlag);
	InFlag = Chain.getValue(1);

	SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Glue);
	SDValue Ops[] = { Chain, DAG.getValueType(AVT), InFlag };
	SDValue RepMovs = DAG.getNode(X86ISD::REP_MOVS, dl, Tys, Ops);

	SmallVector<SDValue, 4> Results;
	Results.push_back(RepMovs);
	if (BytesLeft) {
	// Handle the last 1 - 7 bytes.
	unsigned Offset = SizeVal - BytesLeft;
	EVT DstVT = Dst.getValueType();
	EVT SrcVT = Src.getValueType();
	EVT SizeVT = Size.getValueType();
	Results.push_back(DAG.getMemcpy(Chain, dl,
	DAG.getNode(ISD::ADD, dl, DstVT, Dst,
	DAG.getConstant(Offset, DstVT)),
	DAG.getNode(ISD::ADD, dl, SrcVT, Src,
	DAG.getConstant(Offset, SrcVT)),
	DAG.getConstant(BytesLeft, SizeVT),
	Align, isVolatile, AlwaysInline, false,
	DstPtrInfo.getWithOffset(Offset),
	SrcPtrInfo.getWithOffset(Offset)));
	}

	return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Results);
	}