MergeFunctions.cpp File Reference

#include "llvm/Transforms/IPO/MergeFunctions.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/StructuralHash.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Transforms/Utils/FunctionComparator.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
#include <algorithm>
#include <cassert>
#include <iterator>
#include <set>
#include <utility>
#include <vector>

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "mergefunc"

Functions
	STATISTIC (NumFunctionsMerged, "Number of functions merged")
	STATISTIC (NumThunksWritten, "Number of thunks generated")
	STATISTIC (NumAliasesWritten, "Number of aliases generated")
	STATISTIC (NumDoubleWeak, "Number of new functions created")
static bool	hasDistinctMetadataIntrinsic (const Function &F)
	Check whether F has an intrinsic which references distinct metadata as an operand.
static bool	isEligibleForMerging (Function &F)
	Check whether F is eligible for function merging.
static Value *	createCast (IRBuilder<> &Builder, Value *V, Type *DestTy)
static bool	canCreateThunkFor (Function *F)
	Whether this function may be replaced by a forwarding thunk.
static void	copyMetadataIfPresent (Function *From, Function *To, StringRef Kind)
	Copy all metadata of a specific kind from one function to another.
static bool	canCreateAliasFor (Function *F)
static bool	isFuncOrderCorrect (const Function *F, const Function *G)

Variables
static cl::opt< unsigned >	NumFunctionsForVerificationCheck ("mergefunc-verify", cl::desc("How many functions in a module could be used for " "MergeFunctions to pass a basic correctness check. " "'0' disables this check. Works only with '-debug' key."), cl::init(0), cl::Hidden)
static cl::opt< bool >	MergeFunctionsPDI ("mergefunc-preserve-debug-info", cl::Hidden, cl::init(false), cl::desc("Preserve debug info in thunk when mergefunc " "transformations are made."))
static cl::opt< bool >	MergeFunctionsAliases ("mergefunc-use-aliases", cl::Hidden, cl::init(false), cl::desc("Allow mergefunc to create aliases"))

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "mergefunc"

Definition at line 132 of file MergeFunctions.cpp.

Function Documentation

canCreateAliasFor()

static bool canCreateAliasFor ( Function *  F )

static

Definition at line 817 of file MergeFunctions.cpp.

References assert(), F, and MergeFunctionsAliases.

canCreateThunkFor()

static bool canCreateThunkFor ( Function *  F )

static

Whether this function may be replaced by a forwarding thunk.

Definition at line 699 of file MergeFunctions.cpp.

References llvm::dbgs(), F, and LLVM_DEBUG.

copyMetadataIfPresent()

static void copyMetadataIfPresent ( Function *  From, Function *  To, StringRef  Kind  )

static

Copy all metadata of a specific kind from one function to another.

Definition at line 716 of file MergeFunctions.cpp.

References llvm::GlobalObject::addMetadata(), and From.

createCast()

static Value * createCast ( IRBuilder<> &  Builder, Value *  V, Type *  DestTy  )

static

Definition at line 489 of file MergeFunctions.cpp.

References assert(), llvm::IRBuilderBase::CreateBitCast(), createCast(), llvm::IRBuilderBase::CreateExtractValue(), llvm::IRBuilderBase::CreateInsertValue(), llvm::IRBuilderBase::CreateIntToPtr(), llvm::IRBuilderBase::CreatePtrToInt(), llvm::PoisonValue::get(), llvm::Type::getStructElementType(), llvm::Type::getStructNumElements(), I, llvm::Type::isIntegerTy(), llvm::Type::isPointerTy(), and llvm::Type::isStructTy().

Referenced by createCast().

hasDistinctMetadataIntrinsic()

static bool hasDistinctMetadataIntrinsic ( const Function &  F )

static

Check whether F has an intrinsic which references distinct metadata as an operand.

The most common instance of this would be CFI checks for function-local types.

Definition at line 388 of file MergeFunctions.cpp.

References F, I, and N.

Referenced by isEligibleForMerging().

isEligibleForMerging()

static bool isEligibleForMerging ( Function &  F )

static

Check whether F is eligible for function merging.

Definition at line 408 of file MergeFunctions.cpp.

References F, and hasDistinctMetadataIntrinsic().

isFuncOrderCorrect()

static bool isFuncOrderCorrect ( const Function *  F, const Function *  G  )

static

Definition at line 961 of file MergeFunctions.cpp.

References F, and G.

STATISTIC() [1/4]

STATISTIC	(	NumAliasesWritten	,
		"Number of aliases generated"
	)

STATISTIC() [2/4]

STATISTIC	(	NumDoubleWeak	,
		"Number of new functions created"
	)

STATISTIC() [3/4]

STATISTIC	(	NumFunctionsMerged	,
		"Number of functions merged"
	)

STATISTIC() [4/4]

STATISTIC	(	NumThunksWritten	,
		"Number of thunks generated"
	)

Variable Documentation

MergeFunctionsAliases

cl::opt< bool > MergeFunctionsAliases("mergefunc-use-aliases", cl::Hidden, cl::init(false), cl::desc("Allow mergefunc to create aliases")) ( "mergefunc-use-aliases"  , cl::Hidden  , cl::init(false)  , cl::desc("Allow mergefunc to create aliases")    )

static

Referenced by canCreateAliasFor().

MergeFunctionsPDI

cl::opt< bool > MergeFunctionsPDI("mergefunc-preserve-debug-info", cl::Hidden, cl::init(false), cl::desc("Preserve debug info in thunk when mergefunc " "transformations are made.")) ( "mergefunc-preserve-debug-info"  , cl::Hidden  , cl::init(false)  , cl::desc("Preserve debug info in thunk when mergefunc " "transformations are made.")    )

static

NumFunctionsForVerificationCheck

cl::opt< unsigned > NumFunctionsForVerificationCheck("mergefunc-verify", cl::desc("How many functions in a module could be used for " "MergeFunctions to pass a basic correctness check. " "'0' disables this check. Works only with '-debug' key."), cl::init(0), cl::Hidden) ( "mergefunc-verify"  , cl::desc("How many functions in a module could be used for " "MergeFunctions to pass a basic correctness check. " "'0' disables this check. Works only with '-debug' key.")  , cl::init(0)  , cl::Hidden    )

static