#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallBitVector.h"
#include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
#include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
#include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h"
#include "llvm/CodeGen/GlobalISel/LegalizerHelper.h"
#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/LowLevelType.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterBankInfo.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DivisionByConstantInfo.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetMachine.h"
#include <cmath>
#include <optional>
#include <tuple>

Include dependency graph for CombinerHelper.cpp:

Macros
#define	DEBUG_TYPE "gi-combiner"

Functions
static unsigned	littleEndianByteAt (const unsigned ByteWidth, const unsigned I)

static Register	buildLogBase2 (Register V, MachineIRBuilder &MIB)
	Determines the LogBase2 value for a non-null input value using the transform: LogBase2(V) = (EltBits - 1) - ctlz(V).

static unsigned	bigEndianByteAt (const unsigned ByteWidth, const unsigned I)

static std::optional< bool >	isBigEndian (const SmallDenseMap< int64_t, int64_t, 8 > &MemOffset2Idx, int64_t LowestIdx)
	Given a map from byte offsets in memory to indices in a load/store, determine if that map corresponds to a little or big endian byte pattern.

static unsigned	getExtLoadOpcForExtend (unsigned ExtOpc)

static Type *	getTypeForLLT (LLT Ty, LLVMContext &C)

static std::optional< APFloat >	constantFoldFpUnary (unsigned Opcode, LLT DstTy, const Register Op, const MachineRegisterInfo &MRI)

static Register	peekThroughBitcast (Register Reg, const MachineRegisterInfo &MRI)

static LLT	getMidVTForTruncRightShiftCombine (LLT ShiftTy, LLT TruncTy)

static bool	isConstValidTrue (const TargetLowering &TLI, unsigned ScalarSizeBits, int64_t Cst, bool IsVector, bool IsFP)

static std::optional< std::pair< GZExtLoad *, int64_t > >	matchLoadAndBytePosition (Register Reg, unsigned MemSizeInBits, const MachineRegisterInfo &MRI)
	Helper function for findLoadOffsetsForLoadOrCombine.

static std::optional< int64_t >	getTruncStoreByteOffset (GStore &Store, Register &SrcVal, MachineRegisterInfo &MRI)
	Check if the store `Store` is a truncstore that can be merged.

static bool	isContractableFMul (MachineInstr &MI, bool AllowFusionGlobally)
	Checks if `MI` is TargetOpcode::G_FMUL and contractable either due to global flags or MachineInstr flags.

static bool	hasMoreUses (const MachineInstr &MI0, const MachineInstr &MI1, const MachineRegisterInfo &MRI)

Variables
static cl::opt< bool >	ForceLegalIndexing ("force-legal-indexing", cl::Hidden, cl::init(false), cl::desc("Force all indexed operations to be " "legal for the GlobalISel combiner"))

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "gi-combiner"

Definition at line 39 of file CombinerHelper.cpp.

Function Documentation

◆ bigEndianByteAt()

static unsigned bigEndianByteAt	(	const unsigned	ByteWidth,
		const unsigned	I
	)

static

Returns: The big endian in-memory byte position of byte I in a ByteWidth bytes wide type.

E.g. Given a 4-byte type x, x[0] -> byte 3

Definition at line 89 of file CombinerHelper.cpp.

References assert(), and I.

Referenced by isBigEndian(), and llvm::CombinerHelper::matchLoadOrCombine().

◆ buildLogBase2()

static Register buildLogBase2	(	Register	V,
		MachineIRBuilder &	MIB
	)

static

Determines the LogBase2 value for a non-null input value using the transform: LogBase2(V) = (EltBits - 1) - ctlz(V).

Definition at line 77 of file CombinerHelper.cpp.

References llvm::sampleprof::Base, llvm::MachineIRBuilder::buildConstant(), llvm::MachineIRBuilder::buildCTLZ(), llvm::MachineIRBuilder::buildSub(), llvm::MachineIRBuilder::getMRI(), llvm::MachineInstrBuilder::getReg(), llvm::LLT::getScalarSizeInBits(), and MRI.

Referenced by llvm::CombinerHelper::applyUMulHToLShr().

◆ constantFoldFpUnary()

static std::optional< APFloat > constantFoldFpUnary	(	unsigned	Opcode,
		LLT	DstTy,
		const Register	Op,
		const MachineRegisterInfo &	MRI
	)

static

Definition at line 1292 of file CombinerHelper.cpp.

References llvm::getConstantFPVRegVal(), llvm::getFltSemanticForLLT(), llvm::ConstantFP::getValueAPF(), llvm::APFloatBase::IEEEdouble(), llvm_unreachable, llvm::log2(), MRI, and llvm::APFloatBase::rmNearestTiesToEven.

Referenced by llvm::CombinerHelper::matchCombineConstantFoldFpUnary().

◆ getExtLoadOpcForExtend()

static unsigned getExtLoadOpcForExtend ( unsigned ExtOpc )

static

Definition at line 495 of file CombinerHelper.cpp.

References llvm_unreachable.

Referenced by llvm::CombinerHelper::applyCombineExtendingLoads(), and llvm::CombinerHelper::matchCombineExtendingLoads().

◆ getMidVTForTruncRightShiftCombine()

static LLT getMidVTForTruncRightShiftCombine	(	LLT	ShiftTy,
		LLT	TruncTy
	)

static

Definition at line 2281 of file CombinerHelper.cpp.

References llvm::LLT::changeElementSize(), and llvm::LLT::getScalarSizeInBits().

Referenced by llvm::CombinerHelper::matchCombineTruncOfShift().

◆ getTruncStoreByteOffset()

static std::optional< int64_t > getTruncStoreByteOffset	(	GStore &	Store,
		Register &	SrcVal,
		MachineRegisterInfo &	MRI
	)

static

Check if the store Store is a truncstore that can be merged.

That is, it's a store of a shifted value of SrcVal. If SrcVal is an empty Register then it does not need to match and SrcVal is set to the source value found. On match, returns the start byte offset of the SrcVal that is being stored.

Definition at line 3635 of file CombinerHelper.cpp.

References llvm::Register::isValid(), llvm::MIPatternMatch::m_any_of(), llvm::MIPatternMatch::m_GAShr(), llvm::MIPatternMatch::m_GLShr(), llvm::MIPatternMatch::m_GTrunc(), llvm::MIPatternMatch::m_ICst(), llvm::MIPatternMatch::m_Reg(), llvm::MIPatternMatch::mi_match(), MRI, and llvm::Offset.

Referenced by llvm::CombinerHelper::matchTruncStoreMerge().

◆ getTypeForLLT()

static Type * getTypeForLLT	(	LLT	Ty,
		LLVMContext &	C
	)

static

Definition at line 1268 of file CombinerHelper.cpp.

References llvm::CallingConv::C, llvm::IntegerType::get(), llvm::FixedVectorType::get(), llvm::LLT::getNumElements(), llvm::LLT::getScalarSizeInBits(), llvm::LLT::getSizeInBits(), and llvm::LLT::isVector().

Referenced by llvm::CombinerHelper::matchPtrAddImmedChain().

◆ hasMoreUses()

static bool hasMoreUses	(	const MachineInstr &	MI0,
		const MachineInstr &	MI1,
		const MachineRegisterInfo &	MRI
	)

static

Definition at line 5318 of file CombinerHelper.cpp.

References llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), and MRI.

Referenced by llvm::CombinerHelper::matchCombineFAddFMAFMulToFMadOrFMA(), llvm::CombinerHelper::matchCombineFAddFMulToFMadOrFMA(), llvm::CombinerHelper::matchCombineFAddFpExtFMulToFMadOrFMA(), llvm::CombinerHelper::matchCombineFAddFpExtFMulToFMadOrFMAAggressive(), and llvm::CombinerHelper::matchCombineFSubFMulToFMadOrFMA().

◆ isBigEndian()

static std::optional< bool > isBigEndian	(	const SmallDenseMap< int64_t, int64_t, 8 > &	MemOffset2Idx,
		int64_t	LowestIdx
	)

static

Given a map from byte offsets in memory to indices in a load/store, determine if that map corresponds to a little or big endian byte pattern.

Parameters

MemOffset2Idx	maps memory offsets to address offsets.
LowestIdx	is the lowest index in `MemOffset2Idx`.

Returns: true if the map corresponds to a big endian byte pattern, false if it corresponds to a little endian byte pattern, and std::nullopt otherwise.

E.g. given a 32-bit type x, and x[AddrOffset], the in-memory byte patterns are as follows:

AddrOffset Little endian Big endian 0 0 3 1 1 2 2 2 1 3 3 0

Definition at line 112 of file CombinerHelper.cpp.

References assert(), bigEndianByteAt(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), Idx, littleEndianByteAt(), and llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::size().

Referenced by collectInsertionElements(), createGPRPairNode(), llvm::SelectionDAG::getConstant(), llvm::CombinerHelper::matchLoadOrCombine(), PerformSTORECombine(), llvm::LegalizerHelper::reduceLoadStoreWidth(), ReplaceCMP_SWAP_64Results(), and llvm::orc::OrcMips32_Base::writeResolverCode().

◆ isConstValidTrue()

static bool isConstValidTrue	(	const TargetLowering &	TLI,
		unsigned	ScalarSizeBits,
		int64_t	Cst,
		bool	IsVector,
		bool	IsFP
	)

static

Definition at line 2987 of file CombinerHelper.cpp.

References llvm::isConstTrueVal().

Referenced by llvm::CombinerHelper::matchNotCmp().

◆ isContractableFMul()

static bool isContractableFMul	(	MachineInstr &	MI,
		bool	AllowFusionGlobally
	)

static

Checks if MI is TargetOpcode::G_FMUL and contractable either due to global flags or MachineInstr flags.

Definition at line 5312 of file CombinerHelper.cpp.

References llvm::MachineInstr::FmContract, and MI.

◆ littleEndianByteAt()

static unsigned littleEndianByteAt	(	const unsigned	ByteWidth,
		const unsigned	I
	)

static

Returns: The little endian in-memory byte position of byte I in a ByteWidth bytes wide type.

E.g. Given a 4-byte type x, x[0] -> byte 0

Definition at line 70 of file CombinerHelper.cpp.

References assert(), and I.

Referenced by isBigEndian(), and llvm::CombinerHelper::matchLoadOrCombine().

◆ matchLoadAndBytePosition()

static std::optional< std::pair< GZExtLoad *, int64_t > > matchLoadAndBytePosition	(	Register	Reg,
		unsigned	MemSizeInBits,
		const MachineRegisterInfo &	MRI
	)

static

Helper function for findLoadOffsetsForLoadOrCombine.

Check if Reg is the result of loading a MemSizeInBits wide value, and then moving that value into a specific byte offset.

e.g. x[i] << 24

Returns: The load instruction and the byte offset it is moved into.

Definition at line 3355 of file CombinerHelper.cpp.

References assert(), llvm::MIPatternMatch::m_GShl(), llvm::MIPatternMatch::m_ICst(), llvm::MIPatternMatch::m_OneNonDBGUse(), llvm::MIPatternMatch::m_Reg(), llvm::MIPatternMatch::mi_match(), and MRI.

◆ peekThroughBitcast()

static Register peekThroughBitcast	(	Register	Reg,
		const MachineRegisterInfo &	MRI
	)

static

Definition at line 1722 of file CombinerHelper.cpp.

References llvm::MIPatternMatch::m_GBitcast(), llvm::MIPatternMatch::m_Reg(), llvm::MIPatternMatch::mi_match(), and MRI.

Referenced by llvm::CombinerHelper::matchCombineUnmergeMergeToPlainValues().

Variable Documentation

◆ ForceLegalIndexing

cl::opt< bool > ForceLegalIndexing("force-legal-indexing", cl::Hidden, cl::init(false), cl::desc("Force all indexed operations to be " "legal for the GlobalISel combiner"))	(	"force-legal-indexing"	,
		cl::Hidden	,
		cl::init(false)	,
		cl::desc("Force all indexed operations to be " "legal for the GlobalISel combiner")
	)

static

Referenced by llvm::CombinerHelper::matchCombineIndexedLoadStore().

Macros

Functions

Variables

Macro Definition Documentation

◆ DEBUG_TYPE

Function Documentation

◆ bigEndianByteAt()

◆ buildLogBase2()

◆ constantFoldFpUnary()

◆ getExtLoadOpcForExtend()

◆ getMidVTForTruncRightShiftCombine()

◆ getTruncStoreByteOffset()

◆ getTypeForLLT()

◆ hasMoreUses()

◆ isBigEndian()

◆ isConstValidTrue()

◆ isContractableFMul()

◆ littleEndianByteAt()

◆ matchLoadAndBytePosition()

◆ peekThroughBitcast()

Variable Documentation

◆ ForceLegalIndexing