PrologEpilogInserter.cpp File Reference

#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <limits>
#include <utility>
#include <vector>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "prologepilog"

Typedefs
using	MBBVector = SmallVector< MachineBasicBlock *, 4 >
using	StackObjSet = SmallSetVector< int, 8 >
	StackObjSet - A set of stack object indexes.
using	SavedDbgValuesMap = SmallDenseMap< MachineBasicBlock *, SmallVector< MachineInstr *, 4 >, 4 >

Functions
	STATISTIC (NumLeafFuncWithSpills, "Number of leaf functions with CSRs")
	STATISTIC (NumFuncSeen, "Number of functions seen in PEI")
	INITIALIZE_PASS_BEGIN (PEI, DEBUG_TYPE, "Prologue/Epilogue Insertion", false, false) INITIALIZE_PASS_END(PEI
	STATISTIC (NumBytesStackSpace, "Number of bytes used for stack in all functions")
static void	stashEntryDbgValues (MachineBasicBlock &MBB, SavedDbgValuesMap &EntryDbgValues)
	Stash DBG_VALUEs that describe parameters and which are placed at the start of the block.
static void	assignCalleeSavedSpillSlots (MachineFunction &F, const BitVector &SavedRegs, unsigned &MinCSFrameIndex, unsigned &MaxCSFrameIndex)
static void	updateLiveness (MachineFunction &MF)
	Helper function to update the liveness information for the callee-saved registers.
static void	insertCSRSaves (MachineBasicBlock &SaveBlock, ArrayRef< CalleeSavedInfo > CSI)
	Insert spill code for the callee-saved registers used in the function.
static void	insertCSRRestores (MachineBasicBlock &RestoreBlock, std::vector< CalleeSavedInfo > &CSI)
	Insert restore code for the callee-saved registers used in the function.
static void	AdjustStackOffset (MachineFrameInfo &MFI, int FrameIdx, bool StackGrowsDown, int64_t &Offset, Align &MaxAlign)
	AdjustStackOffset - Helper function used to adjust the stack frame offset.
static void	computeFreeStackSlots (MachineFrameInfo &MFI, bool StackGrowsDown, unsigned MinCSFrameIndex, unsigned MaxCSFrameIndex, int64_t FixedCSEnd, BitVector &StackBytesFree)
	Compute which bytes of fixed and callee-save stack area are unused and keep track of them in StackBytesFree.
static bool	scavengeStackSlot (MachineFrameInfo &MFI, int FrameIdx, bool StackGrowsDown, Align MaxAlign, BitVector &StackBytesFree)
	Assign frame object to an unused portion of the stack in the fixed stack object range.
static void	AssignProtectedObjSet (const StackObjSet &UnassignedObjs, SmallSet< int, 16 > &ProtectedObjs, MachineFrameInfo &MFI, bool StackGrowsDown, int64_t &Offset, Align &MaxAlign)
	AssignProtectedObjSet - Helper function to assign large stack objects (i.e., those required to be close to the Stack Protector) to stack offsets.

Variables
	DEBUG_TYPE
Prologue Epilogue Insertion &Frame	Finalization
Prologue Epilogue Insertion &Frame	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "prologepilog"

Definition at line 70 of file PrologEpilogInserter.cpp.

Typedef Documentation

MBBVector

using MBBVector = SmallVector<MachineBasicBlock *, 4>

Definition at line 72 of file PrologEpilogInserter.cpp.

SavedDbgValuesMap

using SavedDbgValuesMap = SmallDenseMap<MachineBasicBlock *, SmallVector<MachineInstr *, 4>, 4>

Definition at line 175 of file PrologEpilogInserter.cpp.

StackObjSet

using StackObjSet = SmallSetVector<int, 8>

StackObjSet - A set of stack object indexes.

Definition at line 173 of file PrologEpilogInserter.cpp.

Function Documentation

AdjustStackOffset()

static void AdjustStackOffset ( MachineFrameInfo &  MFI, int  FrameIdx, bool  StackGrowsDown, int64_t &  Offset, Align &  MaxAlign  )

inlinestatic

AdjustStackOffset - Helper function used to adjust the stack frame offset.

Definition at line 698 of file PrologEpilogInserter.cpp.

References llvm::alignTo(), llvm::dbgs(), llvm::MachineFrameInfo::getObjectAlign(), llvm::MachineFrameInfo::getObjectSize(), LLVM_DEBUG, llvm::Offset, and llvm::MachineFrameInfo::setObjectOffset().

Referenced by AssignProtectedObjSet().

assignCalleeSavedSpillSlots()

static void assignCalleeSavedSpillSlots ( MachineFunction &  F, const BitVector &  SavedRegs, unsigned &  MinCSFrameIndex, unsigned &  MaxCSFrameIndex  )

static

Definition at line 430 of file PrologEpilogInserter.cpp.

References llvm::TargetFrameLowering::assignCalleeSavedSpillSlots(), llvm::MachineFrameInfo::CreateFixedSpillStackObject(), llvm::MachineFrameInfo::CreateStackObject(), llvm::BitVector::empty(), F, llvm::TargetFrameLowering::getCalleeSavedSpillSlots(), llvm::TargetFrameLowering::getStackAlign(), llvm::TargetFrameLowering::SpillSlot::Offset, llvm::TargetFrameLowering::SpillSlot::Reg, llvm::BitVector::set(), llvm::MachineFrameInfo::setCalleeSavedInfo(), llvm::BitVector::size(), Size, and llvm::BitVector::test().

AssignProtectedObjSet()

void LocalStackSlotImpl::AssignProtectedObjSet ( const StackObjSet &  UnassignedObjs, SmallSet< int, 16 > &  ProtectedObjs, MachineFrameInfo &  MFI, bool  StackGrowsDown, int64_t &  Offset, Align &  MaxAlign  )

static

AssignProtectedObjSet - Helper function to assign large stack objects (i.e., those required to be close to the Stack Protector) to stack offsets.

Definition at line 833 of file PrologEpilogInserter.cpp.

References AdjustStackOffset(), llvm::SmallSet< T, N, C >::insert(), and llvm::Offset.

computeFreeStackSlots()

static void computeFreeStackSlots ( MachineFrameInfo &  MFI, bool  StackGrowsDown, unsigned  MinCSFrameIndex, unsigned  MaxCSFrameIndex, int64_t  FixedCSEnd, BitVector &  StackBytesFree  )

inlinestatic

Compute which bytes of fixed and callee-save stack area are unused and keep track of them in StackBytesFree.

Definition at line 729 of file PrologEpilogInserter.cpp.

References llvm::TargetStackID::Default, llvm::MachineFrameInfo::getObjectIndexBegin(), llvm::MachineFrameInfo::getObjectOffset(), llvm::MachineFrameInfo::getObjectSize(), llvm::MachineFrameInfo::getStackID(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::BitVector::reset(), and llvm::BitVector::resize().

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	PEI	,
		DEBUG_TYPE	,
		"Prologue/Epilogue Insertion"	,
		false	,
		false
	)

insertCSRRestores()

static void insertCSRRestores ( MachineBasicBlock &  RestoreBlock, std::vector< CalleeSavedInfo > &  CSI  )

static

Insert restore code for the callee-saved registers used in the function.

Definition at line 624 of file PrologEpilogInserter.cpp.

References llvm::MachineInstrBuilder::addReg(), assert(), llvm::MachineBasicBlock::begin(), llvm::BuildMI(), llvm::MachineBasicBlock::getFirstTerminator(), llvm::TargetSubtargetInfo::getFrameLowering(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::getKillRegState(), llvm::MachineBasicBlock::getParent(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), I, llvm::HexagonInstrInfo::loadRegFromStackSlot(), llvm::TargetFrameLowering::restoreCalleeSavedRegisters(), llvm::reverse(), TII, and TRI.

insertCSRSaves()

static void insertCSRSaves ( MachineBasicBlock &  SaveBlock, ArrayRef< CalleeSavedInfo >  CSI  )

static

Insert spill code for the callee-saved registers used in the function.

Definition at line 597 of file PrologEpilogInserter.cpp.

References llvm::MachineInstrBuilder::addReg(), llvm::MachineBasicBlock::begin(), llvm::BuildMI(), llvm::TargetSubtargetInfo::getFrameLowering(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::getKillRegState(), llvm::MachineBasicBlock::getParent(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), I, llvm::TargetFrameLowering::spillCalleeSavedRegisters(), llvm::HexagonInstrInfo::storeRegToStackSlot(), TII, and TRI.

scavengeStackSlot()

static bool scavengeStackSlot ( MachineFrameInfo &  MFI, int  FrameIdx, bool  StackGrowsDown, Align  MaxAlign, BitVector &  StackBytesFree  )

inlinestatic

Assign frame object to an unused portion of the stack in the fixed stack object range.

Return true if the allocation was successful.

Definition at line 773 of file PrologEpilogInserter.cpp.

References llvm::alignTo(), llvm::BitVector::clear(), llvm::dbgs(), llvm::BitVector::find_first(), llvm::BitVector::find_next(), llvm::MachineFrameInfo::getObjectAlign(), llvm::MachineFrameInfo::getObjectSize(), llvm::MachineFrameInfo::isVariableSizedObjectIndex(), LLVM_DEBUG, llvm::BitVector::none(), llvm::BitVector::reset(), llvm::MachineFrameInfo::setObjectOffset(), llvm::BitVector::size(), and llvm::BitVector::test().

stashEntryDbgValues()

static void stashEntryDbgValues ( MachineBasicBlock &  MBB, SavedDbgValuesMap &  EntryDbgValues  )

static

Stash DBG_VALUEs that describe parameters and which are placed at the start of the block.

Later on, after the prologue code has been emitted, the stashed DBG_VALUEs will be reinserted at the start of the block.

Definition at line 181 of file PrologEpilogInserter.cpp.

References llvm::any_of(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::count(), llvm::DIExpression::fragmentsOverlap(), MBB, MI, llvm::none_of(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

STATISTIC() [1/3]

STATISTIC	(	NumBytesStackSpace	,
		"Number of bytes used for stack in all functions"
	)

STATISTIC() [2/3]

STATISTIC	(	NumFuncSeen	,
		"Number of functions seen in PEI"
	)

STATISTIC() [3/3]

STATISTIC	(	NumLeafFuncWithSpills	,
		"Number of leaf functions with CSRs"
	)

updateLiveness()

static void updateLiveness ( MachineFunction &  MF )

static

Helper function to update the liveness information for the callee-saved registers.

Definition at line 525 of file PrologEpilogInserter.cpp.

References llvm::MachineBasicBlock::addLiveIn(), llvm::SmallVectorBase< Size_T >::empty(), llvm::MachineFunction::front(), llvm::MachineFrameInfo::getCalleeSavedInfo(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFunction::getRegInfo(), llvm::MachineFrameInfo::getRestorePoint(), llvm::MachineFrameInfo::getSavePoint(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::MachineBasicBlock::isLiveIn(), MBB, MRI, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::MachineBasicBlock::successors().

Variable Documentation

DEBUG_TYPE

DEBUG_TYPE

Definition at line 153 of file PrologEpilogInserter.cpp.

false

Prologue Epilogue Insertion& Frame false

Definition at line 154 of file PrologEpilogInserter.cpp.

Finalization

Prologue Epilogue Insertion& Frame Finalization

Definition at line 154 of file PrologEpilogInserter.cpp.