MachineFunctionSplitter.cpp File Reference

#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/EHUtils.h"
#include "llvm/Analysis/ProfileSummaryInfo.h"
#include "llvm/CodeGen/BasicBlockSectionUtils.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
#include <optional>

Go to the source code of this file.

Functions
static void	setDescendantEHBlocksCold (MachineFunction &MF)
	setDescendantEHBlocksCold - This splits all EH pads and blocks reachable only by EH pad as cold.
static void	finishAdjustingBasicBlocksAndLandingPads (MachineFunction &MF)
static bool	isColdBlock (const MachineBasicBlock &MBB, const MachineBlockFrequencyInfo *MBFI, ProfileSummaryInfo *PSI)
	INITIALIZE_PASS (MachineFunctionSplitter, "machine-function-splitter", "Split machine functions using profile information", false, false) MachineFunctionPass *llvm

Variables
static cl::opt< unsigned >	PercentileCutoff ("mfs-psi-cutoff", cl::desc("Percentile profile summary cutoff used to " "determine cold blocks. Unused if set to zero."), cl::init(999950), cl::Hidden)
static cl::opt< unsigned >	ColdCountThreshold ("mfs-count-threshold", cl::desc("Minimum number of times a block must be executed to be retained."), cl::init(1), cl::Hidden)
static cl::opt< bool >	SplitAllEHCode ("mfs-split-ehcode", cl::desc("Splits all EH code and it's descendants by default."), cl::init(false), cl::Hidden)

Function Documentation

finishAdjustingBasicBlocksAndLandingPads()

static void finishAdjustingBasicBlocksAndLandingPads ( MachineFunction &  MF )

static

Definition at line 100 of file MachineFunctionSplitter.cpp.

References llvm::avoidZeroOffsetLandingPad(), llvm::sortBasicBlocksAndUpdateBranches(), X, and Y.

INITIALIZE_PASS()

INITIALIZE_PASS	(	MachineFunctionSplitter	,
		"machine-function-splitter"	,
		"Split machine functions using profile information"	,
		false	,
		false
	)

Definition at line 213 of file MachineFunctionSplitter.cpp.

isColdBlock()

static bool isColdBlock ( const MachineBasicBlock &  MBB, const MachineBlockFrequencyInfo *  MBFI, ProfileSummaryInfo *  PSI  )

static

Definition at line 108 of file MachineFunctionSplitter.cpp.

References ColdCountThreshold, llvm::MachineBlockFrequencyInfo::getBlockProfileCount(), llvm::TargetSubtargetInfo::getInstrInfo(), llvm::MachineBasicBlock::getParent(), llvm::MachineFunction::getSubtarget(), llvm::ProfileSummaryInfo::hasCSInstrumentationProfile(), llvm::ProfileSummaryInfo::hasInstrumentationProfile(), llvm::ProfileSummaryInfo::hasSampleProfile(), llvm::ProfileSummaryInfo::isColdCountNthPercentile(), MBB, PercentileCutoff, and TII.

setDescendantEHBlocksCold()

static void setDescendantEHBlocksCold ( MachineFunction &  MF )

static

setDescendantEHBlocksCold - This splits all EH pads and blocks reachable only by EH pad as cold.

This will help mark EH pads statically cold instead of relying on profile data.

Definition at line 92 of file MachineFunctionSplitter.cpp.

References llvm::Block, llvm::MBBSectionID::ColdSectionID, and llvm::computeEHOnlyBlocks().

Variable Documentation

ColdCountThreshold

cl::opt< unsigned > ColdCountThreshold("mfs-count-threshold", cl::desc( "Minimum number of times a block must be executed to be retained."), cl::init(1), cl::Hidden) ( "mfs-count-threshold"  , cl::desc( "Minimum number of times a block must be executed to be retained.")  , cl::init(1)  , cl::Hidden    )

static

Referenced by annotateAllFunctions(), llvm::ProfileSummaryBuilder::getColdCountThreshold(), isColdBlock(), llvm::sampleprof::SampleContextTrimmer::trimAndMergeColdContextProfiles(), and verifyFuncBFI().

PercentileCutoff

cl::opt< unsigned > PercentileCutoff("mfs-psi-cutoff", cl::desc("Percentile profile summary cutoff used to " "determine cold blocks. Unused if set to zero."), cl::init(999950), cl::Hidden) ( "mfs-psi-cutoff"  , cl::desc("Percentile profile summary cutoff used to " "determine cold blocks. Unused if set to zero.")  , cl::init(999950)  , cl::Hidden    )

static

Referenced by isColdBlock(), llvm::ProfileSummaryInfo::isColdBlockNthPercentile(), llvm::ProfileSummaryInfo::isColdCountNthPercentile(), llvm::ProfileSummaryInfo::isFunctionColdInCallGraphNthPercentile(), llvm::ProfileSummaryInfo::isFunctionHotInCallGraphNthPercentile(), llvm::ProfileSummaryInfo::isHotBlockNthPercentile(), and llvm::ProfileSummaryInfo::isHotCountNthPercentile().

SplitAllEHCode

cl::opt< bool > SplitAllEHCode("mfs-split-ehcode", cl::desc("Splits all EH code and it's descendants by default."), cl::init(false), cl::Hidden) ( "mfs-split-ehcode"  , cl::desc("Splits all EH code and it's descendants by default.")  , cl::init(false)  , cl::Hidden    )

static