LLVM  4.0.0
Macros | Functions | Variables
IfConversion.cpp File Reference
#include "llvm/CodeGen/Passes.h"
#include "BranchFolding.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LivePhysRegs.h"
#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/TargetSchedule.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/TargetLowering.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include <algorithm>
#include <utility>
Include dependency graph for IfConversion.cpp:

Go to the source code of this file.

Macros

#define DEBUG_TYPE   "ifcvt"
 

Functions

 STATISTIC (NumSimple,"Number of simple if-conversions performed")
 
 STATISTIC (NumSimpleFalse,"Number of simple (F) if-conversions performed")
 
 STATISTIC (NumTriangle,"Number of triangle if-conversions performed")
 
 STATISTIC (NumTriangleRev,"Number of triangle (R) if-conversions performed")
 
 STATISTIC (NumTriangleFalse,"Number of triangle (F) if-conversions performed")
 
 STATISTIC (NumTriangleFRev,"Number of triangle (F/R) if-conversions performed")
 
 STATISTIC (NumDiamonds,"Number of diamond if-conversions performed")
 
 STATISTIC (NumForkedDiamonds,"Number of forked-diamond if-conversions performed")
 
 STATISTIC (NumIfConvBBs,"Number of if-converted blocks")
 
 STATISTIC (NumDupBBs,"Number of duplicated blocks")
 
 STATISTIC (NumUnpred,"Number of true blocks of diamonds unpredicated")
 
static MachineBasicBlockfindFalseBlock (MachineBasicBlock *BB, MachineBasicBlock *TrueBB)
 BB has a fallthrough. Find its 'false' successor given its 'true' successor. More...
 
static MachineBasicBlockgetNextBlock (MachineBasicBlock &MBB)
 Returns the next block in the function blocks ordering. More...
 
static void shrinkInclusiveRange (MachineBasicBlock::iterator &Begin, MachineBasicBlock::iterator &It, bool &Empty)
 Shrink the provided inclusive range by one instruction. More...
 
static void verifySameBranchInstructions (MachineBasicBlock *MBB1, MachineBasicBlock *MBB2)
 
static bool canFallThroughTo (MachineBasicBlock &MBB, MachineBasicBlock &ToMBB)
 Returns true either if ToMBB is the next block after MBB or that all the intervening blocks are empty (given MBB can fall through to its next block). More...
 
static void InsertUncondBranch (MachineBasicBlock &MBB, MachineBasicBlock &ToMBB, const TargetInstrInfo *TII)
 Inserts an unconditional branch from MBB to ToMBB. More...
 
static void UpdatePredRedefs (MachineInstr &MI, LivePhysRegs &Redefs)
 Behaves like LiveRegUnits::StepForward() but also adds implicit uses to all values defined in MI which are also live/used by MI. More...
 
static void RemoveKills (MachineInstr &MI, const LivePhysRegs &DontKill)
 Remove kill flags from operands with a registers in the DontKill set. More...
 
static void RemoveKills (MachineBasicBlock::iterator I, MachineBasicBlock::iterator E, const LivePhysRegs &DontKill, const MCRegisterInfo &MCRI)
 Walks a range of machine instructions and removes kill flags for registers in the DontKill set. More...
 
static bool MaySpeculate (const MachineInstr &MI, SmallSet< unsigned, 4 > &LaterRedefs)
 

Variables

static cl::opt< int > IfCvtFnStart ("ifcvt-fn-start", cl::init(-1), cl::Hidden)
 
static cl::opt< int > IfCvtFnStop ("ifcvt-fn-stop", cl::init(-1), cl::Hidden)
 
static cl::opt< int > IfCvtLimit ("ifcvt-limit", cl::init(-1), cl::Hidden)
 
static cl::opt< boolDisableSimple ("disable-ifcvt-simple", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableSimpleF ("disable-ifcvt-simple-false", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableTriangle ("disable-ifcvt-triangle", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableTriangleR ("disable-ifcvt-triangle-rev", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableTriangleF ("disable-ifcvt-triangle-false", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableTriangleFR ("disable-ifcvt-triangle-false-rev", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableDiamond ("disable-ifcvt-diamond", cl::init(false), cl::Hidden)
 
static cl::opt< boolDisableForkedDiamond ("disable-ifcvt-forked-diamond", cl::init(false), cl::Hidden)
 
static cl::opt< boolIfCvtBranchFold ("ifcvt-branch-fold", cl::init(true), cl::Hidden)
 

Macro Definition Documentation

#define DEBUG_TYPE   "ifcvt"

Definition at line 42 of file IfConversion.cpp.

Function Documentation

static bool canFallThroughTo ( MachineBasicBlock MBB,
MachineBasicBlock ToMBB 
)
static

Returns true either if ToMBB is the next block after MBB or that all the intervening blocks are empty (given MBB can fall through to its next block).

Definition at line 1344 of file IfConversion.cpp.

References E, llvm::MachineFunction::end(), llvm::ilist_node_impl< OptionsT >::getIterator(), and llvm::MachineBasicBlock::getParent().

static MachineBasicBlock* findFalseBlock ( MachineBasicBlock BB,
MachineBasicBlock TrueBB 
)
static

BB has a fallthrough. Find its 'false' successor given its 'true' successor.

Definition at line 492 of file IfConversion.cpp.

References llvm::MachineBasicBlock::successors().

static MachineBasicBlock* getNextBlock ( MachineBasicBlock MBB)
inlinestatic

Returns the next block in the function blocks ordering.

If it is the end, returns NULL.

Definition at line 516 of file IfConversion.cpp.

References E, llvm::MachineFunction::end(), llvm::ilist_node_impl< OptionsT >::getIterator(), llvm::MachineBasicBlock::getParent(), and I.

static void InsertUncondBranch ( MachineBasicBlock MBB,
MachineBasicBlock ToMBB,
const TargetInstrInfo TII 
)
static

Inserts an unconditional branch from MBB to ToMBB.

Definition at line 1372 of file IfConversion.cpp.

References llvm::TargetInstrInfo::insertBranch().

static bool MaySpeculate ( const MachineInstr MI,
SmallSet< unsigned, 4 > &  LaterRedefs 
)
static
static void RemoveKills ( MachineInstr MI,
const LivePhysRegs DontKill 
)
static

Remove kill flags from operands with a registers in the DontKill set.

Definition at line 1450 of file IfConversion.cpp.

References llvm::LivePhysRegs::contains(), and llvm::MachineOperandIteratorBase::isValid().

Referenced by RemoveKills().

static void RemoveKills ( MachineBasicBlock::iterator  I,
MachineBasicBlock::iterator  E,
const LivePhysRegs DontKill,
const MCRegisterInfo MCRI 
)
static

Walks a range of machine instructions and removes kill flags for registers in the DontKill set.

Definition at line 1461 of file IfConversion.cpp.

References llvm::make_range(), MI, and RemoveKills().

static void shrinkInclusiveRange ( MachineBasicBlock::iterator Begin,
MachineBasicBlock::iterator It,
bool Empty 
)
inlinestatic

Shrink the provided inclusive range by one instruction.

If the range was one instruction (It == Begin), It is not modified, but Empty is set to true.

Definition at line 594 of file IfConversion.cpp.

Referenced by verifySameBranchInstructions().

STATISTIC ( NumSimple  ,
"Number of simple if-conversions performed"   
)
STATISTIC ( NumSimpleFalse  ,
"Number of simple (F) if-conversions performed"   
)
STATISTIC ( NumTriangle  ,
"Number of triangle if-conversions performed"   
)
STATISTIC ( NumTriangleRev  ,
"Number of triangle (R) if-conversions performed"   
)
STATISTIC ( NumTriangleFalse  ,
"Number of triangle (F) if-conversions performed"   
)
STATISTIC ( NumTriangleFRev  ,
"Number of triangle (F/R) if-conversions performed"   
)
STATISTIC ( NumDiamonds  ,
"Number of diamond if-conversions performed"   
)
STATISTIC ( NumForkedDiamonds  ,
"Number of forked-diamond if-conversions performed"   
)
STATISTIC ( NumIfConvBBs  ,
"Number of if-converted blocks"   
)
STATISTIC ( NumDupBBs  ,
"Number of duplicated blocks"   
)
STATISTIC ( NumUnpred  ,
"Number of true blocks of diamonds unpredicated"   
)
static void UpdatePredRedefs ( MachineInstr MI,
LivePhysRegs Redefs 
)
static
static void verifySameBranchInstructions ( MachineBasicBlock MBB1,
MachineBasicBlock MBB2 
)
static

Variable Documentation

cl::opt<bool> DisableDiamond("disable-ifcvt-diamond", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableForkedDiamond("disable-ifcvt-forked-diamond", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableSimple("disable-ifcvt-simple", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableSimpleF("disable-ifcvt-simple-false", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableTriangle("disable-ifcvt-triangle", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableTriangleF("disable-ifcvt-triangle-false", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableTriangleFR("disable-ifcvt-triangle-false-rev", cl::init(false), cl::Hidden)
static
cl::opt<bool> DisableTriangleR("disable-ifcvt-triangle-rev", cl::init(false), cl::Hidden)
static
cl::opt<bool> IfCvtBranchFold("ifcvt-branch-fold", cl::init(true), cl::Hidden)
static
cl::opt<int> IfCvtFnStart("ifcvt-fn-start", cl::init(-1), cl::Hidden)
static
cl::opt<int> IfCvtFnStop("ifcvt-fn-stop", cl::init(-1), cl::Hidden)
static
cl::opt<int> IfCvtLimit("ifcvt-limit", cl::init(-1), cl::Hidden)
static