LLVM  4.0.0
Macros | Functions | Variables
TwoAddressInstructionPass.cpp File Reference
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.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/CodeGen/Passes.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/Support/raw_ostream.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:

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Macros

#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)
 Test if the given register value, which is used by the given instruction, is killed by the given instruction. More...
 
static MachineInstrgetSingleDef (unsigned Reg, MachineBasicBlock *BB, const MachineRegisterInfo *MRI)
 Return the MachineInstr* if it is the single def of the Reg in current BB. More...
 
static bool isCopyToReg (MachineInstr &MI, const TargetInstrInfo *TII, unsigned &SrcReg, unsigned &DstReg, bool &IsSrcPhys, bool &IsDstPhys)
 Return true if the specified MI is a copy instruction or an extract_subreg instruction. More...
 
static bool isKilled (MachineInstr &MI, unsigned Reg, const MachineRegisterInfo *MRI, const TargetInstrInfo *TII, LiveIntervals *LIS, bool allowFalsePositives)
 Test if the given register value, which is used by the given instruction, is killed by the given instruction. More...
 
static bool isTwoAddrUse (MachineInstr &MI, unsigned Reg, unsigned &DstReg)
 Return true if the specified MI uses the specified register as a two-address use. More...
 
static MachineInstrfindOnlyInterestingUse (unsigned Reg, MachineBasicBlock *MBB, MachineRegisterInfo *MRI, const TargetInstrInfo *TII, bool &IsCopy, unsigned &DstReg, bool &IsDstPhys)
 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. More...
 
static unsigned getMappedReg (unsigned Reg, DenseMap< unsigned, unsigned > &RegMap)
 Return the physical register the specified virtual register might be mapped to. More...
 
static bool regsAreCompatible (unsigned RegA, unsigned RegB, const TargetRegisterInfo *TRI)
 Return true if the two registers are equal or aliased. More...
 
static bool regOverlapsSet (const SmallVectorImpl< unsigned > &Set, unsigned Reg, const TargetRegisterInfo *TRI)
 

Variables

static cl::opt< boolEnableRescheduling ("twoaddr-reschedule", cl::desc("Coalesce copies by rescheduling (default=true)"), cl::init(true), cl::Hidden)
 
 twoaddressinstruction
 
Two Address instruction pass
 
Two Address instruction false
 

Macro Definition Documentation

#define DEBUG_TYPE   "twoaddrinstr"

Definition at line 55 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

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 492 of file TwoAddressInstructionPass.cpp.

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

static unsigned getMappedReg ( unsigned  Reg,
DenseMap< unsigned, unsigned > &  RegMap 
)
static
static MachineInstr* getSingleDef ( unsigned  Reg,
MachineBasicBlock BB,
const MachineRegisterInfo MRI 
)
static

Return the MachineInstr* if it is the single def of the Reg in current BB.

Definition at line 315 of file TwoAddressInstructionPass.cpp.

References llvm::MachineRegisterInfo::def_instructions(), and llvm::MipsISD::Ret.

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

Return true if the specified MI is a copy instruction or an extract_subreg instruction.

It also returns the source and destination registers and whether they are physical registers by reference.

Definition at line 379 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

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 442 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 MI.

static bool isPlainlyKilled ( MachineInstr MI,
unsigned  Reg,
LiveIntervals LIS 
)
static
static bool isTwoAddrUse ( MachineInstr MI,
unsigned  Reg,
unsigned DstReg 
)
static

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 475 of file TwoAddressInstructionPass.cpp.

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

Referenced by findOnlyInterestingUse().

static bool regOverlapsSet ( const SmallVectorImpl< unsigned > &  Set,
unsigned  Reg,
const TargetRegisterInfo TRI 
)
static
static bool regsAreCompatible ( unsigned  RegA,
unsigned  RegB,
const TargetRegisterInfo TRI 
)
static

Return true if the two registers are equal or aliased.

Definition at line 534 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 177 of file TwoAddressInstructionPass.cpp.

Two Address instruction pass

Definition at line 177 of file TwoAddressInstructionPass.cpp.

twoaddressinstruction

Definition at line 177 of file TwoAddressInstructionPass.cpp.