TwoAddressInstructionPass.cpp File Reference

#include "llvm/CodeGen/Passes.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"

Include dependency graph for TwoAddressInstructionPass.cpp:

Go to the source code of this file.

Defines
#define	DEBUG_TYPE   "twoaddrinstr"
Functions
	STATISTIC (NumTwoAddressInstrs,"Number of two-address instructions")
	STATISTIC (NumCommuted,"Number of instructions commuted to coalesce")
	STATISTIC (NumAggrCommuted,"Number of instructions aggressively commuted")
	STATISTIC (NumConvertedTo3Addr,"Number of instructions promoted to 3-address")
	STATISTIC (Num3AddrSunk,"Number of 3-address instructions sunk")
	STATISTIC (NumReSchedUps,"Number of instructions re-scheduled up")
	STATISTIC (NumReSchedDowns,"Number of instructions re-scheduled down")
	INITIALIZE_PASS_BEGIN (TwoAddressInstructionPass,"twoaddressinstruction","Two-Address instruction pass", false, false) INITIALIZE_PASS_END(TwoAddressInstructionPass
static bool	isPlainlyKilled (MachineInstr *MI, unsigned Reg, LiveIntervals *LIS)
	isPLainlyKilled - Test if the given register value, which is used by the
static bool	isCopyToReg (MachineInstr &MI, const TargetInstrInfo *TII, unsigned &SrcReg, unsigned &DstReg, bool &IsSrcPhys, bool &IsDstPhys)
static bool	isKilled (MachineInstr &MI, unsigned Reg, const MachineRegisterInfo *MRI, const TargetInstrInfo *TII, LiveIntervals *LIS, bool allowFalsePositives)
static bool	isTwoAddrUse (MachineInstr &MI, unsigned Reg, unsigned &DstReg)
static MachineInstr *	findOnlyInterestingUse (unsigned Reg, MachineBasicBlock *MBB, MachineRegisterInfo *MRI, const TargetInstrInfo *TII, bool &IsCopy, unsigned &DstReg, bool &IsDstPhys)
static unsigned	getMappedReg (unsigned Reg, DenseMap< unsigned, unsigned > &RegMap)
static bool	regsAreCompatible (unsigned RegA, unsigned RegB, const TargetRegisterInfo *TRI)
Variables
static cl::opt< bool >	EnableRescheduling ("twoaddr-reschedule", cl::desc("Coalesce copies by rescheduling (default=true)"), cl::init(true), cl::Hidden)
	twoaddressinstruction
Two Address instruction	pass
Two Address instruction	false

---

Define Documentation

#define DEBUG_TYPE   "twoaddrinstr"

Definition at line 54 of file TwoAddressInstructionPass.cpp.

---

Function Documentation

static MachineInstr* findOnlyInterestingUse	(	unsigned	Reg,
		MachineBasicBlock *	MBB,
		MachineRegisterInfo *	MRI,
		const TargetInstrInfo *	TII,
		bool &	IsCopy,
		unsigned &	DstReg,
		bool &	IsDstPhys
	)		[static]

findOnlyInterestingUse - Given a register, if has a single in-basic block use, return the use instruction if it's a copy or a two-address use.

Definition at line 452 of file TwoAddressInstructionPass.cpp.

References llvm::MachineInstr::getParent(), llvm::MachineRegisterInfo::hasOneNonDBGUse(), isCopyToReg(), llvm::TargetRegisterInfo::isPhysicalRegister(), isTwoAddrUse(), and llvm::MachineRegisterInfo::use_instr_nodbg_begin().

static unsigned getMappedReg	(	unsigned	Reg,
		DenseMap< unsigned, unsigned > &	RegMap
	)		[static]

getMappedReg - Return the physical register the specified virtual register might be mapped to.

Definition at line 480 of file TwoAddressInstructionPass.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT >::find(), llvm::TargetRegisterInfo::isPhysicalRegister(), and llvm::TargetRegisterInfo::isVirtualRegister().

INITIALIZE_PASS_BEGIN	(	TwoAddressInstructionPass	,
		"twoaddressinstruction"	,
		"Two-Address instruction pass"	,
		false	,
		false
	)

static bool isCopyToReg	(	MachineInstr &	MI,
		const TargetInstrInfo *	TII,
		unsigned &	SrcReg,
		unsigned &	DstReg,
		bool &	IsSrcPhys,
		bool &	IsDstPhys
	)		[static]

isCopyToReg - Return true if the specified MI is a copy instruction or a extract_subreg instruction. It also returns the source and destination registers and whether they are physical registers by reference.

Definition at line 339 of file TwoAddressInstructionPass.cpp.

References llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), llvm::MachineInstr::isCopy(), llvm::MachineInstr::isInsertSubreg(), llvm::TargetRegisterInfo::isPhysicalRegister(), and llvm::MachineInstr::isSubregToReg().

Referenced by findOnlyInterestingUse(), and isKilled().

static bool isKilled	(	MachineInstr &	MI,
		unsigned	Reg,
		const MachineRegisterInfo *	MRI,
		const TargetInstrInfo *	TII,
		LiveIntervals *	LIS,
		bool	allowFalsePositives
	)		[static]

isKilled - Test if the given register value, which is used by the given instruction, is killed by the given instruction. This looks through coalescable copies to see if the original value is potentially not killed.

For example, in this code:

reg1034 = copy reg1024 reg1035 = copy reg1025<kill> reg1036 = add reg1034<kill>, reg1035<kill>

reg1034 is not considered to be killed, since it is copied from a register which is not killed. Treating it as not killed lets the normal heuristics commute the (two-address) add, which lets coalescing eliminate the extra copy.

If allowFalsePositives is true then likely kills are treated as kills even if it can't be proven that they are kills.

Definition at line 402 of file TwoAddressInstructionPass.cpp.

References llvm::MachineRegisterInfo::def_begin(), llvm::MachineRegisterInfo::def_end(), llvm::MachineOperand::getParent(), llvm::MachineRegisterInfo::hasOneUse(), isCopyToReg(), llvm::TargetRegisterInfo::isPhysicalRegister(), isPlainlyKilled(), and llvm::AArch64CC::MI.

static bool isPlainlyKilled	(	MachineInstr *	MI,
		unsigned	Reg,
		LiveIntervals *	LIS
	)		[static]

isPLainlyKilled - Test if the given register value, which is used by the

Definition at line 360 of file TwoAddressInstructionPass.cpp.

References llvm::LiveRange::end(), llvm::LiveRange::find(), llvm::LiveIntervals::getInstructionIndex(), llvm::LiveIntervals::getInterval(), llvm::LiveRange::hasAtLeastOneValue(), I, llvm::LiveIntervals::isNotInMIMap(), llvm::SlotIndex::isSameInstr(), llvm::TargetRegisterInfo::isVirtualRegister(), llvm::MachineInstr::killsRegister(), and LI.

Referenced by isKilled().

static bool isTwoAddrUse	(	MachineInstr &	MI,
		unsigned	Reg,
		unsigned &	DstReg
	)		[static]

isTwoAddrUse - Return true if the specified MI uses the specified register as a two-address use. If so, return the destination register by reference.

Definition at line 435 of file TwoAddressInstructionPass.cpp.

References llvm::MachineInstr::getNumOperands(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), llvm::MachineOperand::isReg(), llvm::MachineInstr::isRegTiedToDefOperand(), and llvm::MachineOperand::isUse().

Referenced by findOnlyInterestingUse().

static bool regsAreCompatible	(	unsigned	RegA,
		unsigned	RegB,
		const TargetRegisterInfo *	TRI
	)		[static]

regsAreCompatible - Return true if the two registers are equal or aliased.

Definition at line 495 of file TwoAddressInstructionPass.cpp.

References llvm::TargetRegisterInfo::regsOverlap().

STATISTIC	(	NumTwoAddressInstrs	,
		"Number of two-address instructions"
	)

STATISTIC	(	NumCommuted	,
		"Number of instructions commuted to coalesce"
	)

STATISTIC	(	NumAggrCommuted	,
		"Number of instructions aggressively commuted"
	)

STATISTIC	(	NumConvertedTo3Addr	,
		"Number of instructions promoted to 3-address"
	)

STATISTIC	(	Num3AddrSunk	,
		"Number of 3-address instructions sunk"
	)

STATISTIC	(	NumReSchedUps	,
		"Number of instructions re-scheduled up"
	)

STATISTIC	(	NumReSchedDowns	,
		"Number of instructions re-scheduled down"
	)

---

Variable Documentation

cl::opt<bool> EnableRescheduling("twoaddr-reschedule", cl::desc("Coalesce copies by rescheduling (default=true)"), cl::init(true), cl::Hidden) [static]

Two Address instruction false

Definition at line 169 of file TwoAddressInstructionPass.cpp.

Two Address instruction pass

Definition at line 169 of file TwoAddressInstructionPass.cpp.

Referenced by LLVMTargetMachineEmit().

twoaddressinstruction

Definition at line 169 of file TwoAddressInstructionPass.cpp.