ARMConstantIslandPass.cpp File Reference

#include "ARM.h"
#include "ARMBaseInstrInfo.h"
#include "ARMBasicBlockInfo.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMSubtarget.h"
#include "MCTargetDesc/ARMBaseInfo.h"
#include "MVETailPredUtils.h"
#include "Thumb2InstrInfo.h"
#include "Utils/ARMBaseInfo.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/LivePhysRegs.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <iterator>
#include <utility>
#include <vector>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "arm-cp-islands"
#define	ARM_CP_ISLANDS_OPT_NAME    "ARM constant island placement and branch shortening pass"

Functions
	STATISTIC (NumCPEs, "Number of constpool entries")
	STATISTIC (NumSplit, "Number of uncond branches inserted")
	STATISTIC (NumCBrFixed, "Number of cond branches fixed")
	STATISTIC (NumUBrFixed, "Number of uncond branches fixed")
	STATISTIC (NumTBs, "Number of table branches generated")
	STATISTIC (NumT2CPShrunk, "Number of Thumb2 constantpool instructions shrunk")
	STATISTIC (NumT2BrShrunk, "Number of Thumb2 immediate branches shrunk")
	STATISTIC (NumCBZ, "Number of CBZ / CBNZ formed")
	STATISTIC (NumJTMoved, "Number of jump table destination blocks moved")
	STATISTIC (NumJTInserted, "Number of jump table intermediate blocks inserted")
	STATISTIC (NumLEInserted, "Number of LE backwards branches inserted")
static bool	AlignBlocks (MachineFunction *MF, const ARMSubtarget *STI)
static bool	CompareMBBNumbers (const MachineBasicBlock *LHS, const MachineBasicBlock *RHS)
	CompareMBBNumbers - Little predicate function to sort the WaterList by MBB ID.
static bool	BBIsJumpedOver (MachineBasicBlock *MBB)
	BBIsJumpedOver - Return true of the specified basic block's only predecessor unconditionally branches to its only successor.
static unsigned	getUnconditionalBrDisp (int Opc)
	getUnconditionalBrDisp - Returns the maximum displacement that can fit in the specific unconditional branch instruction.
static bool	isSimpleIndexCalc (MachineInstr &I, unsigned EntryReg, unsigned BaseReg)
static bool	jumpTableFollowsTB (MachineInstr *JTMI, MachineInstr *CPEMI)
	Returns whether CPEMI is the first instruction in the block immediately following JTMI (assumed to be a TBB or TBH terminator).
static void	RemoveDeadAddBetweenLEAAndJT (MachineInstr *LEAMI, MachineInstr *JumpMI, unsigned &DeadSize)

Variables
static cl::opt< bool >	AdjustJumpTableBlocks ("arm-adjust-jump-tables", cl::Hidden, cl::init(true), cl::desc("Adjust basic block layout to better use TB[BH]"))
static cl::opt< unsigned >	CPMaxIteration ("arm-constant-island-max-iteration", cl::Hidden, cl::init(30), cl::desc("The max number of iteration for converge"))
static cl::opt< bool >	SynthesizeThumb1TBB ("arm-synthesize-thumb-1-tbb", cl::Hidden, cl::init(true), cl::desc("Use compressed jump tables in Thumb-1 by synthesizing an " "equivalent to the TBB/TBH instructions"))

Macro Definition Documentation

ARM_CP_ISLANDS_OPT_NAME

#define ARM_CP_ISLANDS_OPT_NAME    "ARM constant island placement and branch shortening pass"

Definition at line 61 of file ARMConstantIslandPass.cpp.

DEBUG_TYPE

#define DEBUG_TYPE   "arm-cp-islands"

Definition at line 59 of file ARMConstantIslandPass.cpp.

Function Documentation

AlignBlocks()

bool AlignBlocks ( MachineFunction * MF, const ARMSubtarget * STI )

static

Definition at line 342 of file ARMConstantIslandPass.cpp.

References llvm::Aggressive, Changed, llvm::MachineFunction::getFunction(), llvm::TargetMachine::getOptLevel(), llvm::MachineFunction::getTarget(), llvm::ARMSubtarget::getTargetLowering(), llvm::Function::hasOptSize(), llvm::isLoopStart(), MBB, MI, and llvm::reverse().

BBIsJumpedOver()

bool BBIsJumpedOver ( MachineBasicBlock * MBB )

static

BBIsJumpedOver - Return true of the specified basic block's only predecessor unconditionally branches to its only successor.

Definition at line 1170 of file ARMConstantIslandPass.cpp.

References llvm::MachineOperand::getMBB(), llvm::MachineInstr::getOpcode(), llvm::MachineInstr::getOperand(), and MBB.

CompareMBBNumbers()

bool CompareMBBNumbers ( const MachineBasicBlock * LHS, const MachineBasicBlock * RHS )

static

CompareMBBNumbers - Little predicate function to sort the WaterList by MBB ID.

Definition at line 942 of file ARMConstantIslandPass.cpp.

References LHS, and RHS.

getUnconditionalBrDisp()

unsigned getUnconditionalBrDisp ( int Opc )

inlinestatic

getUnconditionalBrDisp - Returns the maximum displacement that can fit in the specific unconditional branch instruction.

Definition at line 1260 of file ARMConstantIslandPass.cpp.

References Opc.

isSimpleIndexCalc()

bool isSimpleIndexCalc ( MachineInstr & I, unsigned EntryReg, unsigned BaseReg )

static

Definition at line 2055 of file ARMConstantIslandPass.cpp.

References I.

jumpTableFollowsTB()

bool jumpTableFollowsTB ( MachineInstr * JTMI, MachineInstr * CPEMI )

static

Returns whether CPEMI is the first instruction in the block immediately following JTMI (assumed to be a TBB or TBH terminator).

If so, we can switch the first register to PC and usually remove the address calculation that preceded it.

Definition at line 2160 of file ARMConstantIslandPass.cpp.

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

RemoveDeadAddBetweenLEAAndJT()

void RemoveDeadAddBetweenLEAAndJT ( MachineInstr * LEAMI, MachineInstr * JumpMI, unsigned & DeadSize )

static

Definition at line 2168 of file ARMConstantIslandPass.cpp.

References llvm::dbgs(), llvm::MachineInstr::eraseFromParent(), llvm::MachineInstr::getOperand(), llvm::MachineOperand::getReg(), I, and LLVM_DEBUG.

STATISTIC() [1/11]

STATISTIC	(	NumCBrFixed	,
		"Number of cond branches fixed"	)

STATISTIC() [2/11]

STATISTIC	(	NumCBZ	,
		"Number of CBZ / CBNZ formed"	)

STATISTIC() [3/11]

STATISTIC	(	NumCPEs	,
		"Number of constpool entries"	)

STATISTIC() [4/11]

STATISTIC	(	NumJTInserted	,
		"Number of jump table intermediate blocks inserted"	)

STATISTIC() [5/11]

STATISTIC	(	NumJTMoved	,
		"Number of jump table destination blocks moved"	)

STATISTIC() [6/11]

STATISTIC	(	NumLEInserted	,
		"Number of LE backwards branches inserted"	)

STATISTIC() [7/11]

STATISTIC	(	NumSplit	,
		"Number of uncond branches inserted"	)

STATISTIC() [8/11]

STATISTIC	(	NumT2BrShrunk	,
		"Number of Thumb2 immediate branches shrunk"	)

STATISTIC() [9/11]

STATISTIC	(	NumT2CPShrunk	,
		"Number of Thumb2 constantpool instructions shrunk"	)

STATISTIC() [10/11]

STATISTIC	(	NumTBs	,
		"Number of table branches generated"	)

STATISTIC() [11/11]

STATISTIC	(	NumUBrFixed	,
		"Number of uncond branches fixed"	)

Variable Documentation

AdjustJumpTableBlocks

cl::opt< bool > AdjustJumpTableBlocks("arm-adjust-jump-tables", cl::Hidden, cl::init(true), cl::desc("Adjust basic block layout to better use TB[BH]")) ( "arm-adjust-jump-tables" , cl::Hidden , cl::init(true) , cl::desc("Adjust basic block layout to better use TB[BH]")  )

static

CPMaxIteration

cl::opt< unsigned > CPMaxIteration("arm-constant-island-max-iteration", cl::Hidden, cl::init(30), cl::desc("The max number of iteration for converge")) ( "arm-constant-island-max-iteration" , cl::Hidden , cl::init(30) , cl::desc("The max number of iteration for converge")  )

static

SynthesizeThumb1TBB

cl::opt< bool > SynthesizeThumb1TBB("arm-synthesize-thumb-1-tbb", cl::Hidden, cl::init(true), cl::desc("Use compressed jump tables in Thumb-1 by synthesizing an " "equivalent to the TBB/TBH instructions")) ( "arm-synthesize-thumb-1-tbb" , cl::Hidden , cl::init(true) , cl::desc("Use compressed jump tables in Thumb-1 by synthesizing an " "equivalent to the TBB/TBH instructions")  )

static