X86SelectionDAGInfo.cpp File Reference (original) (raw)

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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"))

◆ DEBUG_TYPE

#define DEBUG_TYPE "x86-selectiondag-info"

◆ emitConstantSizeRepmov()

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 267 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, SDValue(), Size, and llvm::ISD::TokenFactor.

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

◆ emitConstantSizeRepstos()

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 122 of file X86SelectionDAGInfo.cpp.

References llvm::ISD::ADD, llvm::dyn_cast(), 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, SDValue(), Size, and llvm::ISD::TokenFactor.