#include "X86SelectionDAGInfo.h"
#include "X86ISelLowering.h"
#include "X86InstrInfo.h"
#include "X86RegisterInfo.h"
#include "X86Subtarget.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/TargetLowering.h"

Macros
#define	DEBUG_TYPE "x86-selectiondag-info"

Functions
static MVT	getOptimalRepType (const X86Subtarget &Subtarget, Align Alignment)
	Returns the best type to use with repmovs/repstos depending on alignment.

static SDValue	emitRepstos (const X86Subtarget &Subtarget, SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Val, SDValue Size, MVT AVT)
	Emit a single REP STOSB instruction for a particular constant size.

static SDValue	emitRepstosB (const X86Subtarget &Subtarget, SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Val, uint64_t Size)
	Emit a single REP STOSB instruction for a particular constant size.

static SDValue	emitConstantSizeRepstos (SelectionDAG &DAG, const X86Subtarget &Subtarget, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Val, uint64_t Size, EVT SizeVT, Align Alignment, bool isVolatile, bool AlwaysInline, MachinePointerInfo DstPtrInfo)
	Returns a REP STOS instruction, possibly with a few load/stores to implement a constant size memory set.

static SDValue	emitRepmovs (const X86Subtarget &Subtarget, SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src, SDValue Size, MVT AVT)
	Emit a single REP MOVS{B,W,D,Q} instruction.

static SDValue	emitRepmovsB (const X86Subtarget &Subtarget, SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src, uint64_t Size)
	Emit a single REP MOVSB instruction for a particular constant size.

static SDValue	emitConstantSizeRepmov (SelectionDAG &DAG, const X86Subtarget &Subtarget, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src, uint64_t Size, EVT SizeVT, Align Alignment, bool isVolatile, bool AlwaysInline, MachinePointerInfo DstPtrInfo, MachinePointerInfo SrcPtrInfo)
	Returns a REP MOVS instruction, possibly with a few load/stores to implement a constant size memory copy.

Variables
static cl::opt< bool >	UseFSRMForMemcpy ("x86-use-fsrm-for-memcpy", cl::Hidden, cl::init(false), cl::desc("Use fast short rep mov in memcpy lowering"))

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "x86-selectiondag-info"

Definition at line 24 of file X86SelectionDAGInfo.cpp.

Function Documentation

◆ emitConstantSizeRepmov()

static SDValue emitConstantSizeRepmov	(	SelectionDAG &	DAG,
		const X86Subtarget &	Subtarget,
		const SDLoc &	dl,
		SDValue	Chain,
		SDValue	Dst,
		SDValue	Src,
		uint64_t	Size,
		EVT	SizeVT,
		Align	Alignment,
		bool	isVolatile,
		bool	AlwaysInline,
		MachinePointerInfo	DstPtrInfo,
		MachinePointerInfo	SrcPtrInfo
	)

static

Returns a REP MOVS instruction, possibly with a few load/stores to implement a constant size memory copy.

In some cases where we know REP MOVS is inefficient we return an empty SDValue so the calling code can either generate a load/store sequence or call the runtime memcpy function.

In case we optimize for size, we use repmovsb even if it's less efficient so we can save the loads/stores of the leftover.

TODO: Revisit next line: big copy with ERMSB on march >= haswell are very efficient.

If we have enhanced repmovs we use it.

We assume runtime memcpy will do a better job for unaligned copies when ERMS is not present.

RepMov can process the whole length.

Definition at line 257 of file X86SelectionDAGInfo.cpp.

References llvm::ISD::ADD, assert(), emitRepmovs(), emitRepmovsB(), llvm::SelectionDAG::getConstant(), llvm::MachineFunction::getFunction(), llvm::SelectionDAG::getIntPtrConstant(), llvm::SelectionDAG::getMachineFunction(), llvm::X86Subtarget::getMaxInlineSizeThreshold(), llvm::SelectionDAG::getMemcpy(), llvm::SelectionDAG::getNode(), getOptimalRepType(), llvm::MachinePointerInfo::getWithOffset(), llvm::Function::hasMinSize(), llvm::Offset, Results, Size, and llvm::ISD::TokenFactor.

Referenced by llvm::X86SelectionDAGInfo::EmitTargetCodeForMemcpy().

◆ emitConstantSizeRepstos()

static SDValue emitConstantSizeRepstos	(	SelectionDAG &	DAG,
		const X86Subtarget &	Subtarget,
		const SDLoc &	dl,
		SDValue	Chain,
		SDValue	Dst,
		SDValue	Val,
		uint64_t	Size,
		EVT	SizeVT,
		Align	Alignment,
		bool	isVolatile,
		bool	AlwaysInline,
		MachinePointerInfo	DstPtrInfo
	)

static

Returns a REP STOS instruction, possibly with a few load/stores to implement a constant size memory set.

In some cases where we know REP MOVS is inefficient we return an empty SDValue so the calling code can either generate a store sequence or call the runtime memset function.

In case we optimize for size, we use repstosb even if it's less efficient so we can save the loads/stores of the leftover.

RepStos can process the whole length.

Definition at line 112 of file X86SelectionDAGInfo.cpp.

References llvm::ISD::ADD, emitRepstos(), emitRepstosB(), llvm::SelectionDAG::getConstant(), llvm::MachineFunction::getFunction(), llvm::SelectionDAG::getIntPtrConstant(), llvm::SelectionDAG::getMachineFunction(), llvm::X86Subtarget::getMaxInlineSizeThreshold(), llvm::SelectionDAG::getMemset(), llvm::SelectionDAG::getNode(), getOptimalRepType(), llvm::MachinePointerInfo::getWithOffset(), llvm::Function::hasMinSize(), llvm::Offset, Results, Size, and llvm::ISD::TokenFactor.

Referenced by llvm::X86SelectionDAGInfo::EmitTargetCodeForMemset().

◆ emitRepmovs()

static SDValue emitRepmovs	(	const X86Subtarget &	Subtarget,
		SelectionDAG &	DAG,
		const SDLoc &	dl,
		SDValue	Chain,
		SDValue	Dst,
		SDValue	Src,
		SDValue	Size,
		MVT	AVT
	)

static

Emit a single REP MOVS{B,W,D,Q} instruction.

Definition at line 224 of file X86SelectionDAGInfo.cpp.

References llvm::SelectionDAG::getCopyToReg(), llvm::SelectionDAG::getNode(), llvm::SDValue::getValue(), llvm::SelectionDAG::getValueType(), llvm::SelectionDAG::getVTList(), llvm::X86Subtarget::isTarget64BitLP64(), llvm::X86ISD::REP_MOVS, and Size.

Referenced by emitConstantSizeRepmov(), emitRepmovsB(), and llvm::X86SelectionDAGInfo::EmitTargetCodeForMemcpy().

◆ emitRepmovsB()

static SDValue emitRepmovsB	(	const X86Subtarget &	Subtarget,
		SelectionDAG &	DAG,
		const SDLoc &	dl,
		SDValue	Chain,
		SDValue	Dst,
		SDValue	Src,
		uint64_t	Size
	)

static

Emit a single REP MOVSB instruction for a particular constant size.

Definition at line 246 of file X86SelectionDAGInfo.cpp.

References emitRepmovs(), llvm::SelectionDAG::getIntPtrConstant(), and Size.

Referenced by emitConstantSizeRepmov().

◆ emitRepstos()

static SDValue emitRepstos	(	const X86Subtarget &	Subtarget,
		SelectionDAG &	DAG,
		const SDLoc &	dl,
		SDValue	Chain,
		SDValue	Dst,
		SDValue	Val,
		SDValue	Size,
		MVT	AVT
	)

static

Emit a single REP STOSB instruction for a particular constant size.

Definition at line 64 of file X86SelectionDAGInfo.cpp.

References llvm::SelectionDAG::getCopyToReg(), llvm::SelectionDAG::getNode(), llvm::MVT::getSizeInBits(), llvm::SDValue::getValue(), llvm::SelectionDAG::getValueType(), llvm::SelectionDAG::getVTList(), llvm::X86Subtarget::isTarget64BitLP64(), llvm::X86ISD::REP_STOS, and Size.

Referenced by emitConstantSizeRepstos(), and emitRepstosB().

◆ emitRepstosB()

static SDValue emitRepstosB	(	const X86Subtarget &	Subtarget,
		SelectionDAG &	DAG,
		const SDLoc &	dl,
		SDValue	Chain,
		SDValue	Dst,
		SDValue	Val,
		uint64_t	Size
	)

static

Emit a single REP STOSB instruction for a particular constant size.

Definition at line 101 of file X86SelectionDAGInfo.cpp.

References emitRepstos(), llvm::SelectionDAG::getIntPtrConstant(), and Size.

Referenced by emitConstantSizeRepstos().

◆ getOptimalRepType()

static MVT getOptimalRepType	(	const X86Subtarget &	Subtarget,
		Align	Alignment
	)

static

Returns the best type to use with repmovs/repstos depending on alignment.

Definition at line 31 of file X86SelectionDAGInfo.cpp.

References assert(), llvm::isPowerOf2_64(), and llvm::Align::value().

Referenced by emitConstantSizeRepmov(), and emitConstantSizeRepstos().

Variable Documentation

◆ UseFSRMForMemcpy

cl::opt< bool > UseFSRMForMemcpy("x86-use-fsrm-for-memcpy", cl::Hidden, cl::init(false), cl::desc("Use fast short rep mov in memcpy lowering"))	(	"x86-use-fsrm-for-memcpy"	,
		cl::Hidden	,
		cl::init(false)	,
		cl::desc("Use fast short rep mov in memcpy lowering")
	)

static

Referenced by llvm::X86SelectionDAGInfo::EmitTargetCodeForMemcpy().

Macros

Functions

Variables

Macro Definition Documentation

◆ DEBUG_TYPE

Function Documentation

◆ emitConstantSizeRepmov()

◆ emitConstantSizeRepstos()

◆ emitRepmovs()

◆ emitRepmovsB()

◆ emitRepstos()

◆ emitRepstosB()

◆ getOptimalRepType()

Variable Documentation

◆ UseFSRMForMemcpy