#include <dead_code_elimination.hpp>

Inheritance diagram for dead_code_elimination:

Collaboration diagram for dead_code_elimination:

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Public Member Functions
	dead_code_elimination (const ParameterConstRef _parameters, const application_managerRef AppM, unsigned int function_id, const DesignFlowManagerConstRef design_flow_manager)
	Constructor. More...

	~dead_code_elimination () override
	Destructor. More...

DesignFlowStep_Status	InternalExec () override
	Performs dead code elimination. More...

bool	HasToBeExecuted () const override
	Check if this step has actually to be executed. More...

Public Member Functions inherited from FunctionFrontendFlowStep
	FunctionFrontendFlowStep (const application_managerRef AppM, const unsigned int function_id, const FrontendFlowStepType frontend_flow_step_type, const DesignFlowManagerConstRef design_flow_manager, const ParameterConstRef parameters)
	Constructor. More...

	~FunctionFrontendFlowStep () override
	Destructor. More...

void	ComputeRelationships (DesignFlowStepSet &relationship, const DesignFlowStep::RelationshipType relationship_type) override
	Compute the relationships of a step with other steps. More...

std::string	GetSignature () const override
	Return the signature of this step. More...

std::string	GetName () const override
	Return the name of this design step. More...

DesignFlowStep_Status	Exec () final
	Execute the step. More...

unsigned int	CGetBBVersion () const

unsigned int	GetBitValueVersion () const

void	PrintInitialIR () const override
	Dump the initial intermediate representation. More...

void	PrintFinalIR () const override
	Dump the final intermediate representation. More...

Public Member Functions inherited from FrontendFlowStep
	FrontendFlowStep (const application_managerRef AppM, const FrontendFlowStepType frontend_flow_step_type, const DesignFlowManagerConstRef design_flow_manager, const ParameterConstRef parameters)
	Constructor. More...

	~FrontendFlowStep () override
	Destructor. More...

virtual std::string	GetKindText () const
	Return the name of the type of this frontend flow step. More...

DesignFlowStepFactoryConstRef	CGetDesignFlowStepFactory () const override
	Return the factory to create this type of steps. More...

void	PrintTreeManager (const bool before) const
	Dump the tree manager. More...

Public Member Functions inherited from DesignFlowStep
	DesignFlowStep (const DesignFlowManagerConstRef design_flow_manager, const ParameterConstRef parameters)
	Constructor. More...

virtual	~DesignFlowStep ()
	Destructor. More...

virtual void	Initialize ()
	Initialize the step (i.e., like a constructor, but executed just before exec. More...

DesignFlowStep_Status	GetStatus () const
	Return the status of this design step. More...

virtual void	WriteDot (std::ostream &out) const
	Write the label for a dot graph. More...

bool	IsComposed () const
	Returns if this step is composed. More...

int	CGetDebugLevel () const
	Return the debug level of the step. More...

Static Public Member Functions
static tree_nodeRef	kill_vdef (const tree_managerRef &TM, const tree_nodeRef &vdef)
	Replace virtual ssa definition with gimple nop. More...

static void	fix_sdc_motion (DesignFlowManagerConstRef design_flow_manager, unsigned int function_id, tree_nodeRef removedStmt)

Static Public Member Functions inherited from FunctionFrontendFlowStep
static const std::string	ComputeSignature (const FrontendFlowStepType frontend_flow_step_type, const unsigned int function_id)
	Compute the signature of a function frontend flow step. More...

Static Public Member Functions inherited from FrontendFlowStep
static void	CreateSteps (const DesignFlowManagerConstRef design_flow_manager, const CustomUnorderedSet< std::pair< FrontendFlowStepType, FunctionRelationship >> &frontend_relationships, const application_managerConstRef application_manager, DesignFlowStepSet &relationships)
	Create the relationship steps of a step with other steps starting from already specified dependencies between frontend flow steps. More...

static const std::string	EnumToKindText (const FrontendFlowStepType frontend_flow_step_type)
	Given a frontend flow step type, return the name of the type. More...

Private Member Functions
const CustomUnorderedSet< std::pair< FrontendFlowStepType, FunctionRelationship > >	ComputeFrontendRelationships (const DesignFlowStep::RelationshipType relationship_type) const override
	Return the set of analyses in relationship with this design step. More...

void	kill_uses (const tree_managerRef &TM, const tree_nodeRef &op0) const

tree_nodeRef	add_gimple_nop (const tree_managerRef &TM, const tree_nodeRef &cur_stmt, const blocRef &bb)

void	fix_sdc_motion (tree_nodeRef removedStmt) const

blocRef	move2emptyBB (const tree_managerRef &TM, const unsigned int new_bbi, const statement_list *sl, const blocRef &bb_pred, const unsigned int cand_bb_dest, const unsigned int bb_dest) const

Private Attributes
std::map< unsigned int, bool >	last_writing_memory

std::map< unsigned int, bool >	last_reading_memory

bool	restart_if_opt

bool	restart_mwi_opt

bool	restart_mem

Additional Inherited Members
Public Types inherited from FrontendFlowStep
using	FunctionRelationship = enum { ALL_FUNCTIONS, CALLED_FUNCTIONS, CALLING_FUNCTIONS, SAME_FUNCTION, WHOLE_APPLICATION }
	The different relationship type between function analysis. More...

Public Types inherited from DesignFlowStep
enum	RelationshipType { DEPENDENCE_RELATIONSHIP, INVALIDATION_RELATIONSHIP, PRECEDENCE_RELATIONSHIP }
	The relationship type. More...

Protected Member Functions inherited from FunctionFrontendFlowStep
void	WriteBBGraphDot (const std::string &filename) const
	Write the current version of statement list in dot format. More...

Protected Attributes inherited from FunctionFrontendFlowStep
const FunctionBehaviorRef	function_behavior
	The function behavior of the function to be analyzed. More...

const unsigned int	function_id
	The index of the function to be analyzed. More...

unsigned int	bb_version
	The version of the basic block intermediate representation on which this step has been applied. More...

unsigned int	bitvalue_version
	The version of the bitvalue information on which this step has been applied. More...

Protected Attributes inherited from FrontendFlowStep
const application_managerRef	AppM
	The application manager. More...

const FrontendFlowStepType	frontend_flow_step_type
	The type of this step. More...

unsigned int	print_counter
	Print counter. More...

Protected Attributes inherited from DesignFlowStep
bool	composed
	True if this step represents a composition of design flow steps (e.g., a flow); must be set by specialized constructors. More...

const Wrefcount< const DesignFlowManager >	design_flow_manager
	The design flow manager. More...

const ParameterConstRef	parameters
	Set of input parameters. More...

int	debug_level
	The debug level. More...

const int	output_level
	The output level. More...

Detailed Description

Definition at line 72 of file dead_code_elimination.hpp.

Constructor & Destructor Documentation

◆ dead_code_elimination()

dead_code_elimination::dead_code_elimination	(	const ParameterConstRef	_parameters,
		const application_managerRef	_AppM,
		unsigned int	_function_id,
		const DesignFlowManagerConstRef	_design_flow_manager
	)

Constructor.

header include

Parameters

Param	is the set of the parameters
AppM	is the application manager
function_id	is the index of the function
design_flow_manager	is the design flow manager

STD includes

Definition at line 79 of file dead_code_elimination.cpp.

References DesignFlowStep::debug_level, DEBUG_LEVEL_NONE, GET_CLASS, DesignFlowStep::parameters, and ~dead_code_elimination().

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◆ ~dead_code_elimination()

dead_code_elimination::~dead_code_elimination ( )

overridedefault

Destructor.

Referenced by dead_code_elimination().

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Member Function Documentation

◆ add_gimple_nop()

tree_nodeRef dead_code_elimination::add_gimple_nop	(	const tree_managerRef &	TM,
		const tree_nodeRef &	cur_stmt,
		const blocRef &	bb
	)

private

Parameters

gc
TM
cur_stmt
bb

Returns: tree_nodeRef

Definition at line 261 of file dead_code_elimination.cpp.

References FrontendFlowStep::AppM, tree_manager::create_tree_node(), FunctionFrontendFlowStep::function_id, GET_NODE, tree_manager::GetTreeReindex(), tree_manager::new_tree_node_id(), STR, THROW_ASSERT, TOK, TOK_SCPE, and TOK_SRCP.

Referenced by InternalExec().

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◆ ComputeFrontendRelationships()

const CustomUnorderedSet< std::pair< FrontendFlowStepType, FrontendFlowStep::FunctionRelationship > > dead_code_elimination::ComputeFrontendRelationships ( const DesignFlowStep::RelationshipType relationship_type ) const

overrideprivatevirtual

Return the set of analyses in relationship with this design step.

Parameters

relationship_type is the type of relationship to be considered

Implements FrontendFlowStep.

Definition at line 93 of file dead_code_elimination.cpp.

References CALLED_FUNCTIONS, DesignFlowStep::DEPENDENCE_RELATIONSHIP, DesignFlowStep::GetStatus(), DesignFlowStep::INVALIDATION_RELATIONSHIP, DesignFlowStep::parameters, DesignFlowStep::PRECEDENCE_RELATIONSHIP, restart_if_opt, restart_mem, restart_mwi_opt, SAME_FUNCTION, SUCCESS, THROW_UNREACHABLE, and WHOLE_APPLICATION.

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◆ fix_sdc_motion() [1/2]

void dead_code_elimination::fix_sdc_motion ( tree_nodeRef removedStmt ) const

private

Definition at line 194 of file dead_code_elimination.cpp.

References DesignFlowStep::design_flow_manager, FunctionFrontendFlowStep::function_id, and Wrefcount< T >::lock().

Referenced by InternalExec().

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◆ fix_sdc_motion() [2/2]

void dead_code_elimination::fix_sdc_motion	(	DesignFlowManagerConstRef	design_flow_manager,
		unsigned int	function_id,
		tree_nodeRef	removedStmt
	)

static

Definition at line 178 of file dead_code_elimination.cpp.

References HLSFunctionStep::ComputeSignature(), and GET_INDEX_CONST_NODE.

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◆ HasToBeExecuted()

bool dead_code_elimination::HasToBeExecuted ( ) const

overridevirtual

Check if this step has actually to be executed.

Returns: true if the step has to be executed

Reimplemented from FunctionFrontendFlowStep.

Definition at line 159 of file dead_code_elimination.cpp.

References FrontendFlowStep::AppM, FunctionFrontendFlowStep::function_id, FunctionFrontendFlowStep::HasToBeExecuted(), last_reading_memory, and last_writing_memory.

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◆ InternalExec()

DesignFlowStep_Status dead_code_elimination::InternalExec ( )

overridevirtual

Performs dead code elimination.

single sweep analysis, block by block, from the bottom to up.

Returns: the exit status of this step

Each ssa which is used zero times is eliminated and the uses of the variables used in the assignment are recomputed multi-way and two way IFs simplified when conditions are constants gimple_call without side effects are removed store-load pairs checked for simplification dead stores removed

Retrieve the list of block

find out if it is a gimple_assign

in case of virtual uses it is better not perform the elimination

op0 is the left side of the assignment, op1 is the right side

very strict condition for the elimination

conservative analysis

very strict condition for the elimination

TODO in case read and write values are integers but of different signedness a cast could allow the load/store simplification

check if this load is killed by a following vover

remove same conditions

Fix PHIs

fix vdef

all vovers become vuse

fix vdef

update function memory write flag

conservative analysis

more conservative than really needed

Implements FunctionFrontendFlowStep.

Definition at line 358 of file dead_code_elimination.cpp.

References add_gimple_nop(), FrontendFlowStep::AppM, function_decl::body, ssa_name::CGetDefStmts(), ssa_name::CGetNumberUses(), tree_helper::CGetType(), ssa_name::CGetUseStmts(), DesignFlowStep::debug_level, DEBUG_LEVEL_PEDANTIC, DEBUG_LEVEL_VERY_PEDANTIC, bloc::ENTRY_BLOCK_ID, bloc::EXIT_BLOCK_ID, tree_helper::find_obj_type_ref_function(), fix_sdc_motion(), FunctionFrontendFlowStep::function_behavior, FunctionFrontendFlowStep::function_id, GET_CONST_NODE, GET_INDEX_NODE, GET_NODE, tree_helper::GetConstValue(), FunctionFrontendFlowStep::GetName(), tree_node::GetString(), INDENT_DBG_MEX, tree_node::index, tree_helper::is_a_nop_function_decl(), tree_helper::IsSameType(), tree_helper::IsVectorType(), kill_uses(), kill_vdef(), last_reading_memory, last_writing_memory, max, move2emptyBB(), DesignFlowStep::parameters, phi, function_decl::reading_memory, restart_if_opt, restart_mem, restart_mwi_opt, tree_helper::Size(), sl, STR, SUCCESS, THROW_ASSERT, THROW_ERROR, U, UNCHANGED, function_decl::undefined_flag, and function_decl::writing_memory.

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◆ kill_uses()

void dead_code_elimination::kill_uses	(	const tree_managerRef &	TM,
		const tree_nodeRef &	op0
	)		const

private

Definition at line 199 of file dead_code_elimination.cpp.

References FrontendFlowStep::AppM, BUILTIN_SRCP, tree_helper::CGetType(), tree_manager::create_tree_node(), tree_manager::CreateUniqueIntegerCst(), tree_manager::CreateUniqueRealCst(), DesignFlowStep::debug_level, DEBUG_LEVEL_VERY_PEDANTIC, tree_node::get_kind(), GET_NODE, tree_manager::GetTreeReindex(), INDENT_DBG_MEX, tree_helper::IsComplexType(), tree_helper::IsRealType(), tree_helper::IsVectorType(), tree_manager::new_tree_node_id(), DesignFlowStep::parameters, tree_manager::ReplaceTreeNode(), STR, THROW_ASSERT, TOK, TOK_OP, TOK_SRCP, and TOK_TYPE.

Referenced by InternalExec().

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◆ kill_vdef()

tree_nodeRef dead_code_elimination::kill_vdef	(	const tree_managerRef &	TM,
		const tree_nodeRef &	vdef
	)

static

Replace virtual ssa definition with gimple nop.

Parameters

TM	tree manager instance
vdef	virtual ssa

Returns: tree_nodeRef generated gimple nop statement

Definition at line 244 of file dead_code_elimination.cpp.

References BUILTIN_SRCP, tree_manager::create_tree_node(), FunctionFrontendFlowStep::function_id, GET_INDEX_CONST_NODE, GET_NODE, tree_manager::GetTreeReindex(), tree_manager::new_tree_node_id(), STR, TOK, TOK_SCPE, and TOK_SRCP.

Referenced by CleanVirtuals(), and InternalExec().

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◆ move2emptyBB()

blocRef dead_code_elimination::move2emptyBB	(	const tree_managerRef &	TM,
		const unsigned int	new_bbi,
		const statement_list *	sl,
		const blocRef &	bb_pred,
		const unsigned int	cand_bb_dest,
		const unsigned int	bb_dest
	)		const

private

Create empty basic block

Fix PHIs

Definition at line 293 of file dead_code_elimination.cpp.

References DesignFlowStep::debug_level, DEBUG_LEVEL_VERY_PEDANTIC, GET_NODE, INDENT_DBG_MEX, statement_list::list_of_bloc, phi, and STR.

Referenced by InternalExec().

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Field Documentation

◆ last_reading_memory

std::map<unsigned int, bool> dead_code_elimination::last_reading_memory

private

Definition at line 77 of file dead_code_elimination.hpp.

Referenced by HasToBeExecuted(), and InternalExec().

◆ last_writing_memory

std::map<unsigned int, bool> dead_code_elimination::last_writing_memory

private

Definition at line 75 of file dead_code_elimination.hpp.

Referenced by HasToBeExecuted(), and InternalExec().

◆ restart_if_opt

bool dead_code_elimination::restart_if_opt

private

Definition at line 79 of file dead_code_elimination.hpp.

Referenced by ComputeFrontendRelationships(), and InternalExec().

◆ restart_mem

bool dead_code_elimination::restart_mem

private

Definition at line 83 of file dead_code_elimination.hpp.

Referenced by ComputeFrontendRelationships(), and InternalExec().

◆ restart_mwi_opt

bool dead_code_elimination::restart_mwi_opt

private

Definition at line 81 of file dead_code_elimination.hpp.

Referenced by ComputeFrontendRelationships(), and InternalExec().

The documentation for this class was generated from the following files:

/workspace/src/frontend_analysis/IR_analysis/dead_code_elimination.hpp
/workspace/src/frontend_analysis/IR_analysis/dead_code_elimination.cpp

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ dead_code_elimination()

◆ ~dead_code_elimination()

Member Function Documentation

◆ add_gimple_nop()

◆ ComputeFrontendRelationships()

◆ fix_sdc_motion() [1/2]

◆ fix_sdc_motion() [2/2]

◆ HasToBeExecuted()

◆ InternalExec()

◆ kill_uses()

◆ kill_vdef()

◆ move2emptyBB()

Field Documentation

◆ last_reading_memory

◆ last_writing_memory

◆ restart_if_opt

◆ restart_mem

◆ restart_mwi_opt