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/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/PEI.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

Functions
	STATISTIC (NumLeafFuncWithSpills, "Number of leaf functions with CSRs")
	STATISTIC (NumFuncSeen, "Number of functions seen in PEI")
	INITIALIZE_PASS_BEGIN (PEILegacy, DEBUG_TYPE, "Prologue/Epilogue Insertion", false, false) INITIALIZE_PASS_END(PEILegacy
	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

Initial value:

 
    SmallDenseMap<MachineBasicBlock *, SmallVector<MachineInstr *, 4>, 4>

Definition at line 180 of file PrologEpilogInserter.cpp.

StackObjSet

using StackObjSet = SmallSetVector<int, 8>

StackObjSet - A set of stack object indexes.

Definition at line 178 of file PrologEpilogInserter.cpp.

Function Documentation

AdjustStackOffset()

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 707 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()

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

static

Definition at line 456 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, Reg, llvm::BitVector::set(), llvm::MachineFrameInfo::setCalleeSavedInfo(), Size, llvm::BitVector::size(), and llvm::BitVector::test().

Referenced by llvm::TargetFrameLowering::assignCalleeSavedSpillSlots().

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 842 of file PrologEpilogInserter.cpp.

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

computeFreeStackSlots()

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 738 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	(	PEILegacy	,
		DEBUG_TYPE	,
		"Prologue/Epilogue Insertion"	,
		false	,
		false	)

References DEBUG_TYPE, and INITIALIZE_PASS_DEPENDENCY.

insertCSRRestores()

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

static

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

Definition at line 646 of file PrologEpilogInserter.cpp.

References llvm::MachineBasicBlock::getFirstTerminator(), llvm::TargetSubtargetInfo::getFrameLowering(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::MachineBasicBlock::getParent(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), I, llvm::TargetFrameLowering::restoreCalleeSavedRegister(), llvm::TargetFrameLowering::restoreCalleeSavedRegisters(), llvm::reverse(), TII, and TRI.

insertCSRSaves()

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

static

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

Definition at line 630 of file PrologEpilogInserter.cpp.

References llvm::MachineBasicBlock::begin(), llvm::TargetSubtargetInfo::getFrameLowering(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::MachineBasicBlock::getParent(), llvm::TargetSubtargetInfo::getRegisterInfo(), llvm::MachineFunction::getSubtarget(), I, llvm::TargetFrameLowering::spillCalleeSavedRegister(), llvm::TargetFrameLowering::spillCalleeSavedRegisters(), TII, and TRI.

scavengeStackSlot()

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 782 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()

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 186 of file PrologEpilogInserter.cpp.

References llvm::any_of(), 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"	)

References MI, and OpIdx.

STATISTIC() [3/3]

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

updateLiveness()

void updateLiveness ( MachineFunction & MF )

static

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

Definition at line 551 of file PrologEpilogInserter.cpp.

References assert(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::MachineFunction::front(), llvm::MachineFrameInfo::getCalleeSavedInfo(), llvm::MachineFunction::getFrameInfo(), llvm::MachineFunction::getRegInfo(), llvm::MachineFrameInfo::getRestorePoints(), llvm::MachineFrameInfo::getSavePoints(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), MBB, MRI, llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), Reg, and llvm::MachineBasicBlock::successors().

Variable Documentation

DEBUG_TYPE

DEBUG_TYPE

Definition at line 158 of file PrologEpilogInserter.cpp.

false

Prologue Epilogue Insertion& Frame false

Definition at line 159 of file PrologEpilogInserter.cpp.

Finalization

Prologue Epilogue Insertion& Frame Finalization

Definition at line 159 of file PrologEpilogInserter.cpp.