SimplifyCFGPass.cpp File Reference

#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Scalar/SimplifyCFG.h"
#include <utility>

Include dependency graph for SimplifyCFGPass.cpp:

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "simplifycfg"

Functions
	STATISTIC (NumSimpl, "Number of blocks simplified")
static bool	mergeEmptyReturnBlocks (Function &F)
	If we have more than one empty (other than phi node) return blocks, merge them together to promote recursive block merging. More...
static bool	iterativelySimplifyCFG (Function &F, const TargetTransformInfo &TTI, const SimplifyCFGOptions &Options)
	Call SimplifyCFG on all the blocks in the function, iterating until no more changes are made. More...
static bool	simplifyFunctionCFG (Function &F, const TargetTransformInfo &TTI, const SimplifyCFGOptions &Options)
	INITIALIZE_PASS_BEGIN (CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false, false) INITIALIZE_PASS_END(CFGSimplifyPass

Variables
static cl::opt< unsigned >	UserBonusInstThreshold ("bonus-inst-threshold", cl::Hidden, cl::init(1), cl::desc("Control the number of bonus instructions (default = 1)"))
static cl::opt< bool >	UserKeepLoops ("keep-loops", cl::Hidden, cl::init(true), cl::desc("Preserve canonical loop structure (default = true)"))
static cl::opt< bool >	UserSwitchToLookup ("switch-to-lookup", cl::Hidden, cl::init(false), cl::desc("Convert switches to lookup tables (default = false)"))
static cl::opt< bool >	UserForwardSwitchCond ("forward-switch-cond", cl::Hidden, cl::init(false), cl::desc("Forward switch condition to phi ops (default = false)"))
static cl::opt< bool >	UserSinkCommonInsts ("sink-common-insts", cl::Hidden, cl::init(false), cl::desc("Sink common instructions (default = false)"))
	simplifycfg
Simplify the	CFG
Simplify the	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "simplifycfg"

Definition at line 46 of file SimplifyCFGPass.cpp.

Function Documentation

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	CFGSimplifyPass	,
		"simplifycfg"	,
		"Simplify the CFG"	,
		false	,
		false
	)

Referenced by llvm::SimplifyCFGPass::run().

iterativelySimplifyCFG()

static bool iterativelySimplifyCFG ( Function &  F, const TargetTransformInfo &  TTI, const SimplifyCFGOptions &  Options  )

static

Call SimplifyCFG on all the blocks in the function, iterating until no more changes are made.

Definition at line 148 of file SimplifyCFGPass.cpp.

References llvm::Function::begin(), llvm::Function::end(), llvm::FindFunctionBackedges(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::simplifyCFG(), and llvm::SmallVectorBase::size().

Referenced by simplifyFunctionCFG().

mergeEmptyReturnBlocks()

static bool mergeEmptyReturnBlocks ( Function &  F )

static

If we have more than one empty (other than phi node) return blocks, merge them together to promote recursive block merging.

Definition at line 73 of file SimplifyCFGPass.cpp.

References llvm::PHINode::addIncoming(), llvm::BasicBlock::begin(), llvm::Function::begin(), llvm::PHINode::Create(), llvm::BranchInst::Create(), llvm::dyn_cast(), E, llvm::Function::end(), llvm::Instruction::eraseFromParent(), llvm::BasicBlock::eraseFromParent(), llvm::BasicBlock::front(), llvm::User::getNumOperands(), llvm::User::getOperand(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), I, llvm::pred_begin(), llvm::pred_end(), llvm::Value::replaceAllUsesWith(), llvm::MipsISD::Ret, and llvm::User::setOperand().

Referenced by simplifyFunctionCFG().

simplifyFunctionCFG()

static bool simplifyFunctionCFG ( Function &  F, const TargetTransformInfo &  TTI, const SimplifyCFGOptions &  Options  )

static

Definition at line 174 of file SimplifyCFGPass.cpp.

References iterativelySimplifyCFG(), mergeEmptyReturnBlocks(), and llvm::removeUnreachableBlocks().

Referenced by llvm::SimplifyCFGPass::run().

STATISTIC()

STATISTIC	(	NumSimpl	,
		"Number of blocks simplified"
	)

Variable Documentation

CFG

Simplify the CFG

Definition at line 285 of file SimplifyCFGPass.cpp.

false

Simplify the false

Definition at line 285 of file SimplifyCFGPass.cpp.

simplifycfg

simplifycfg

Definition at line 285 of file SimplifyCFGPass.cpp.

UserBonusInstThreshold

cl::opt<unsigned> UserBonusInstThreshold("bonus-inst-threshold", cl::Hidden, cl::init(1), cl::desc("Control the number of bonus instructions (default = 1)"))

static

Referenced by llvm::SimplifyCFGPass::run(), and llvm::SimplifyCFGPass::SimplifyCFGPass().

UserForwardSwitchCond

cl::opt<bool> UserForwardSwitchCond("forward-switch-cond", cl::Hidden, cl::init(false), cl::desc("Forward switch condition to phi ops (default = false)"))

static

Referenced by llvm::SimplifyCFGPass::run(), and llvm::SimplifyCFGPass::SimplifyCFGPass().

UserKeepLoops

cl::opt<bool> UserKeepLoops("keep-loops", cl::Hidden, cl::init(true), cl::desc("Preserve canonical loop structure (default = true)"))

static

Referenced by llvm::SimplifyCFGPass::run(), and llvm::SimplifyCFGPass::SimplifyCFGPass().

UserSinkCommonInsts

cl::opt<bool> UserSinkCommonInsts("sink-common-insts", cl::Hidden, cl::init(false), cl::desc("Sink common instructions (default = false)"))

static

Referenced by llvm::SimplifyCFGPass::run(), and llvm::SimplifyCFGPass::SimplifyCFGPass().

UserSwitchToLookup

cl::opt<bool> UserSwitchToLookup("switch-to-lookup", cl::Hidden, cl::init(false), cl::desc("Convert switches to lookup tables (default = false)"))

static

Referenced by llvm::SimplifyCFGPass::run(), and llvm::SimplifyCFGPass::SimplifyCFGPass().