Visitor to return Def-Use chain for a given variable in the block/node More...

Detailed Description

Visitor to return Def-Use chain for a given variable in the block/node

Motivation: For global to local variable transformation aka localizer pass, we need to compute Def-Use chains for all global variables. For example, if we have variable usage like:

NEURON {
    RANGE tau, beta
}
 
DERIVATIVE states() {
    ...
    x = alpha
    beta = x + y
    ....
    z = beta
}
 
INITIAL {
   ...
   beta = x + y
   z = beta * 0.1
   alpha = x * y
}

In the above example if we look at variable beta then it's defined before it's usage and hence it can be safely made local. But variable alpha is used in first block and defined in second block. Hence it can't be made local. A variable can be made local if it is defined before it's usage (in all global blocks). We exclude procedures/functions because we expect inlining to be done prior to this pass.

The analysis of if-elseif-else needs special attention because the def-use chain needs re-cursive evaluation in order to find end-result. For example:

IF(...) {
    beta = y
} ELSE {
    IF(...) {
        beta = x
    } ELSE {
        x = beta
    }
}

For if-else statements, in the above example, if the variable is used in any of the if-elseif-else part then it is considered as "used". And this is done recursively from innermost level to the top.

Definition at line 214 of file defuse_analyze_visitor.hpp.

#include <defuse_analyze_visitor.hpp>

Inheritance diagram for nmodl::visitor::DefUseAnalyzeVisitor:

Public Member Functions
	DefUseAnalyzeVisitor ()=delete

	DefUseAnalyzeVisitor (symtab::SymbolTable &symtab)

	DefUseAnalyzeVisitor (symtab::SymbolTable &symtab, bool ignore_verbatim)

void	visit_binary_expression (const ast::BinaryExpression &node) override
	Nmodl grammar doesn't allow assignment operator on rhs (e.g. More...

void	visit_if_statement (const ast::IfStatement &node) override
	visit node of type ast::IfStatement More...

void	visit_function_call (const ast::FunctionCall &node) override
	Nothing to do if called function is not defined or it's external but if there is a function call for internal function that means there is no inlining happened. More...

void	visit_statement_block (const ast::StatementBlock &node) override
	visit node of type ast::StatementBlock More...

void	visit_verbatim (const ast::Verbatim &node) override
	We are not analyzing verbatim blocks yet and hence if there is a verbatim block we assume there is variable usage. More...

DUChain	analyze (const ast::Ast &node, const std::string &name)
	compute def-use chain for a variable within the node More...

unsupported statements
/ we aren't sure how to handle this "yet" and hence variables used in any of the below statements are handled separately
void	visit_reaction_statement (const ast::ReactionStatement &node) override
	unsupported statements : we aren't sure how to handle this "yet" and hence variables used in any of the below statements are handled separately More...

void	visit_non_lin_equation (const ast::NonLinEquation &node) override
	visit node of type ast::NonLinEquation More...

void	visit_lin_equation (const ast::LinEquation &node) override
	visit node of type ast::LinEquation More...

void	visit_from_statement (const ast::FromStatement &node) override
	visit node of type ast::FromStatement More...

void	visit_conserve (const ast::Conserve &node) override
	visit node of type ast::Conserve More...

void	visit_var_name (const ast::VarName &node) override
	visit node of type ast::VarName More...

void	visit_name (const ast::Name &node) override
	visit node of type ast::Name More...

void	visit_indexed_name (const ast::IndexedName &node) override
	visit node of type ast::IndexedName More...

statements
/ nodes that should not be used for def-use chain analysis
void	visit_conductance_hint (const ast::ConductanceHint &node) override
	statements / nodes that should not be used for def-use chain analysis More...

void	visit_local_list_statement (const ast::LocalListStatement &node) override
	visit node of type ast::LocalListStatement More...

void	visit_argument (const ast::Argument &node) override
	visit node of type ast::Argument More...

Private Member Functions
void	process_variable (const std::string &name)

void	process_variable (const std::string &name, int index)

void	update_defuse_chain (const std::string &name)
	Update the Def-Use chain for given variable. More...

void	visit_unsupported_node (const ast::Node &node)

void	visit_with_new_chain (const ast::Node &node, DUState state)

void	start_new_chain (DUState state)

Private Attributes
symtab::SymbolTable *	global_symtab = nullptr
	symbol table containing global variables More...

std::vector< DUInstance > *	current_chain = nullptr
	def-use chain currently being constructed More...

symtab::SymbolTable *	current_symtab = nullptr
	symbol table for current statement block (or of parent block if doesn't have) should be initialized by caller somehow More...

std::stack< symtab::SymbolTable * >	symtab_stack
	symbol tables in call hierarchy More...

std::string	variable_name
	variable for which to construct def-use chain More...

DUVariableType	variable_type
	variable type (Local or Global) More...

bool	unsupported_node = false
	indicate that there is unsupported construct encountered More...

bool	ignore_verbatim = false
	ignore verbatim blocks More...

bool	visiting_lhs = false
	starting visiting lhs of assignment statement More...

std::shared_ptr< const ast::BinaryExpression >	current_binary_expression = nullptr

Additional Inherited Members
Protected Member Functions inherited from nmodl::visitor::ConstAstVisitor
void	visit_node (const ast::Node &node) override
	visit node of type ast::Node More...

void	visit_statement (const ast::Statement &node) override
	visit node of type ast::Statement More...

void	visit_expression (const ast::Expression &node) override
	visit node of type ast::Expression More...

void	visit_block (const ast::Block &node) override
	visit node of type ast::Block More...

void	visit_identifier (const ast::Identifier &node) override
	visit node of type ast::Identifier More...

void	visit_number (const ast::Number &node) override
	visit node of type ast::Number More...

void	visit_string (const ast::String &node) override
	visit node of type ast::String More...

void	visit_integer (const ast::Integer &node) override
	visit node of type ast::Integer More...

void	visit_float (const ast::Float &node) override
	visit node of type ast::Float More...

void	visit_double (const ast::Double &node) override
	visit node of type ast::Double More...

void	visit_boolean (const ast::Boolean &node) override
	visit node of type ast::Boolean More...

void	visit_name (const ast::Name &node) override
	visit node of type ast::Name More...

void	visit_prime_name (const ast::PrimeName &node) override
	visit node of type ast::PrimeName More...

void	visit_indexed_name (const ast::IndexedName &node) override
	visit node of type ast::IndexedName More...

void	visit_var_name (const ast::VarName &node) override
	visit node of type ast::VarName More...

void	visit_argument (const ast::Argument &node) override
	visit node of type ast::Argument More...

void	visit_react_var_name (const ast::ReactVarName &node) override
	visit node of type ast::ReactVarName More...

void	visit_read_ion_var (const ast::ReadIonVar &node) override
	visit node of type ast::ReadIonVar More...

void	visit_write_ion_var (const ast::WriteIonVar &node) override
	visit node of type ast::WriteIonVar More...

void	visit_nonspecific_cur_var (const ast::NonspecificCurVar &node) override
	visit node of type ast::NonspecificCurVar More...

void	visit_electrode_cur_var (const ast::ElectrodeCurVar &node) override
	visit node of type ast::ElectrodeCurVar More...

void	visit_range_var (const ast::RangeVar &node) override
	visit node of type ast::RangeVar More...

void	visit_global_var (const ast::GlobalVar &node) override
	visit node of type ast::GlobalVar More...

void	visit_pointer_var (const ast::PointerVar &node) override
	visit node of type ast::PointerVar More...

void	visit_random_var (const ast::RandomVar &node) override
	visit node of type ast::RandomVar More...

void	visit_bbcore_pointer_var (const ast::BbcorePointerVar &node) override
	visit node of type ast::BbcorePointerVar More...

void	visit_extern_var (const ast::ExternVar &node) override
	visit node of type ast::ExternVar More...

void	visit_param_block (const ast::ParamBlock &node) override
	visit node of type ast::ParamBlock More...

void	visit_independent_block (const ast::IndependentBlock &node) override
	visit node of type ast::IndependentBlock More...

void	visit_assigned_block (const ast::AssignedBlock &node) override
	visit node of type ast::AssignedBlock More...

void	visit_state_block (const ast::StateBlock &node) override
	visit node of type ast::StateBlock More...

void	visit_initial_block (const ast::InitialBlock &node) override
	visit node of type ast::InitialBlock More...

void	visit_constructor_block (const ast::ConstructorBlock &node) override
	visit node of type ast::ConstructorBlock More...

void	visit_destructor_block (const ast::DestructorBlock &node) override
	visit node of type ast::DestructorBlock More...

void	visit_statement_block (const ast::StatementBlock &node) override
	visit node of type ast::StatementBlock More...

void	visit_derivative_block (const ast::DerivativeBlock &node) override
	visit node of type ast::DerivativeBlock More...

void	visit_linear_block (const ast::LinearBlock &node) override
	visit node of type ast::LinearBlock More...

void	visit_non_linear_block (const ast::NonLinearBlock &node) override
	visit node of type ast::NonLinearBlock More...

void	visit_discrete_block (const ast::DiscreteBlock &node) override
	visit node of type ast::DiscreteBlock More...

void	visit_function_table_block (const ast::FunctionTableBlock &node) override
	visit node of type ast::FunctionTableBlock More...

void	visit_function_block (const ast::FunctionBlock &node) override
	visit node of type ast::FunctionBlock More...

void	visit_procedure_block (const ast::ProcedureBlock &node) override
	visit node of type ast::ProcedureBlock More...

void	visit_net_receive_block (const ast::NetReceiveBlock &node) override
	visit node of type ast::NetReceiveBlock More...

void	visit_solve_block (const ast::SolveBlock &node) override
	visit node of type ast::SolveBlock More...

void	visit_breakpoint_block (const ast::BreakpointBlock &node) override
	visit node of type ast::BreakpointBlock More...

void	visit_before_block (const ast::BeforeBlock &node) override
	visit node of type ast::BeforeBlock More...

void	visit_after_block (const ast::AfterBlock &node) override
	visit node of type ast::AfterBlock More...

void	visit_ba_block (const ast::BABlock &node) override
	visit node of type ast::BABlock More...

void	visit_for_netcon (const ast::ForNetcon &node) override
	visit node of type ast::ForNetcon More...

void	visit_kinetic_block (const ast::KineticBlock &node) override
	visit node of type ast::KineticBlock More...

void	visit_unit_block (const ast::UnitBlock &node) override
	visit node of type ast::UnitBlock More...

void	visit_constant_block (const ast::ConstantBlock &node) override
	visit node of type ast::ConstantBlock More...

void	visit_neuron_block (const ast::NeuronBlock &node) override
	visit node of type ast::NeuronBlock More...

void	visit_unit (const ast::Unit &node) override
	visit node of type ast::Unit More...

void	visit_double_unit (const ast::DoubleUnit &node) override
	visit node of type ast::DoubleUnit More...

void	visit_local_var (const ast::LocalVar &node) override
	visit node of type ast::LocalVar More...

void	visit_limits (const ast::Limits &node) override
	visit node of type ast::Limits More...

void	visit_number_range (const ast::NumberRange &node) override
	visit node of type ast::NumberRange More...

void	visit_constant_var (const ast::ConstantVar &node) override
	visit node of type ast::ConstantVar More...

void	visit_binary_operator (const ast::BinaryOperator &node) override
	visit node of type ast::BinaryOperator More...

void	visit_unary_operator (const ast::UnaryOperator &node) override
	visit node of type ast::UnaryOperator More...

void	visit_reaction_operator (const ast::ReactionOperator &node) override
	visit node of type ast::ReactionOperator More...

void	visit_paren_expression (const ast::ParenExpression &node) override
	visit node of type ast::ParenExpression More...

void	visit_binary_expression (const ast::BinaryExpression &node) override
	visit node of type ast::BinaryExpression More...

void	visit_diff_eq_expression (const ast::DiffEqExpression &node) override
	visit node of type ast::DiffEqExpression More...

void	visit_unary_expression (const ast::UnaryExpression &node) override
	visit node of type ast::UnaryExpression More...

void	visit_non_lin_equation (const ast::NonLinEquation &node) override
	visit node of type ast::NonLinEquation More...

void	visit_lin_equation (const ast::LinEquation &node) override
	visit node of type ast::LinEquation More...

void	visit_function_call (const ast::FunctionCall &node) override
	visit node of type ast::FunctionCall More...

void	visit_watch (const ast::Watch &node) override
	visit node of type ast::Watch More...

void	visit_ba_block_type (const ast::BABlockType &node) override
	visit node of type ast::BABlockType More...

void	visit_unit_def (const ast::UnitDef &node) override
	visit node of type ast::UnitDef More...

void	visit_factor_def (const ast::FactorDef &node) override
	visit node of type ast::FactorDef More...

void	visit_valence (const ast::Valence &node) override
	visit node of type ast::Valence More...

void	visit_unit_state (const ast::UnitState &node) override
	visit node of type ast::UnitState More...

void	visit_local_list_statement (const ast::LocalListStatement &node) override
	visit node of type ast::LocalListStatement More...

void	visit_model (const ast::Model &node) override
	visit node of type ast::Model More...

void	visit_define (const ast::Define &node) override
	visit node of type ast::Define More...

void	visit_include (const ast::Include &node) override
	visit node of type ast::Include More...

void	visit_param_assign (const ast::ParamAssign &node) override
	visit node of type ast::ParamAssign More...

void	visit_assigned_definition (const ast::AssignedDefinition &node) override
	visit node of type ast::AssignedDefinition More...

void	visit_conductance_hint (const ast::ConductanceHint &node) override
	visit node of type ast::ConductanceHint More...

void	visit_expression_statement (const ast::ExpressionStatement &node) override
	visit node of type ast::ExpressionStatement More...

void	visit_protect_statement (const ast::ProtectStatement &node) override
	visit node of type ast::ProtectStatement More...

void	visit_from_statement (const ast::FromStatement &node) override
	visit node of type ast::FromStatement More...

void	visit_while_statement (const ast::WhileStatement &node) override
	visit node of type ast::WhileStatement More...

void	visit_if_statement (const ast::IfStatement &node) override
	visit node of type ast::IfStatement More...

void	visit_else_if_statement (const ast::ElseIfStatement &node) override
	visit node of type ast::ElseIfStatement More...

void	visit_else_statement (const ast::ElseStatement &node) override
	visit node of type ast::ElseStatement More...

void	visit_watch_statement (const ast::WatchStatement &node) override
	visit node of type ast::WatchStatement More...

void	visit_mutex_lock (const ast::MutexLock &node) override
	visit node of type ast::MutexLock More...

void	visit_mutex_unlock (const ast::MutexUnlock &node) override
	visit node of type ast::MutexUnlock More...

void	visit_conserve (const ast::Conserve &node) override
	visit node of type ast::Conserve More...

void	visit_compartment (const ast::Compartment &node) override
	visit node of type ast::Compartment More...

void	visit_lon_difuse (const ast::LonDifuse &node) override
	visit node of type ast::LonDifuse More...

void	visit_reaction_statement (const ast::ReactionStatement &node) override
	visit node of type ast::ReactionStatement More...

void	visit_lag_statement (const ast::LagStatement &node) override
	visit node of type ast::LagStatement More...

void	visit_constant_statement (const ast::ConstantStatement &node) override
	visit node of type ast::ConstantStatement More...

void	visit_table_statement (const ast::TableStatement &node) override
	visit node of type ast::TableStatement More...

void	visit_suffix (const ast::Suffix &node) override
	visit node of type ast::Suffix More...

void	visit_useion (const ast::Useion &node) override
	visit node of type ast::Useion More...

void	visit_nonspecific (const ast::Nonspecific &node) override
	visit node of type ast::Nonspecific More...

void	visit_electrode_current (const ast::ElectrodeCurrent &node) override
	visit node of type ast::ElectrodeCurrent More...

void	visit_range (const ast::Range &node) override
	visit node of type ast::Range More...

void	visit_global (const ast::Global &node) override
	visit node of type ast::Global More...

void	visit_random_var_list (const ast::RandomVarList &node) override
	visit node of type ast::RandomVarList More...

void	visit_pointer (const ast::Pointer &node) override
	visit node of type ast::Pointer More...

void	visit_bbcore_pointer (const ast::BbcorePointer &node) override
	visit node of type ast::BbcorePointer More...

void	visit_external (const ast::External &node) override
	visit node of type ast::External More...

void	visit_thread_safe (const ast::ThreadSafe &node) override
	visit node of type ast::ThreadSafe More...

void	visit_verbatim (const ast::Verbatim &node) override
	visit node of type ast::Verbatim More...

void	visit_line_comment (const ast::LineComment &node) override
	visit node of type ast::LineComment More...

void	visit_block_comment (const ast::BlockComment &node) override
	visit node of type ast::BlockComment More...

void	visit_ontology_statement (const ast::OntologyStatement &node) override
	visit node of type ast::OntologyStatement More...

void	visit_program (const ast::Program &node) override
	visit node of type ast::Program More...

void	visit_nrn_state_block (const ast::NrnStateBlock &node) override
	visit node of type ast::NrnStateBlock More...

void	visit_eigen_newton_solver_block (const ast::EigenNewtonSolverBlock &node) override
	visit node of type ast::EigenNewtonSolverBlock More...

void	visit_eigen_linear_solver_block (const ast::EigenLinearSolverBlock &node) override
	visit node of type ast::EigenLinearSolverBlock More...

void	visit_wrapped_expression (const ast::WrappedExpression &node) override
	visit node of type ast::WrappedExpression More...

void	visit_derivimplicit_callback (const ast::DerivimplicitCallback &node) override
	visit node of type ast::DerivimplicitCallback More...

void	visit_solution_expression (const ast::SolutionExpression &node) override
	visit node of type ast::SolutionExpression More...

void	visit_update_dt (const ast::UpdateDt &node) override
	visit node of type ast::UpdateDt More...

Protected Member Functions inherited from nmodl::visitor::ConstVisitor
virtual	~ConstVisitor ()=default

Constructor & Destructor Documentation

◆ DefUseAnalyzeVisitor() [1/3]

nmodl::visitor::DefUseAnalyzeVisitor::DefUseAnalyzeVisitor ( )

delete

◆ DefUseAnalyzeVisitor() [2/3]

nmodl::visitor::DefUseAnalyzeVisitor::DefUseAnalyzeVisitor ( symtab::SymbolTable & symtab )

inlineexplicit

Definition at line 257 of file defuse_analyze_visitor.hpp.

◆ DefUseAnalyzeVisitor() [3/3]

nmodl::visitor::DefUseAnalyzeVisitor::DefUseAnalyzeVisitor	(	symtab::SymbolTable &	symtab,
		bool	ignore_verbatim
	)

inline

Definition at line 260 of file defuse_analyze_visitor.hpp.

Member Function Documentation

◆ analyze()

DUChain nmodl::visitor::DefUseAnalyzeVisitor::analyze	(	const ast::Ast &	node,
		const std::string &	name
	)

compute def-use chain for a variable within the node

re-initialize state

new chain

analyze given node

Definition at line 419 of file defuse_analyze_visitor.cpp.

◆ process_variable() [1/2]

void nmodl::visitor::DefUseAnalyzeVisitor::process_variable ( const std::string & name )

private

Definition at line 393 of file defuse_analyze_visitor.cpp.

◆ process_variable() [2/2]

void nmodl::visitor::DefUseAnalyzeVisitor::process_variable	(	const std::string &	name,
		int	index
	)

private

Definition at line 399 of file defuse_analyze_visitor.cpp.

◆ start_new_chain()

void nmodl::visitor::DefUseAnalyzeVisitor::start_new_chain ( DUState state )

private

Definition at line 414 of file defuse_analyze_visitor.cpp.

◆ update_defuse_chain()

void nmodl::visitor::DefUseAnalyzeVisitor::update_defuse_chain ( const std::string & name )

private

Update the Def-Use chain for given variable.

Parameters

name	Name of the variable excluding index or dimension

Update def-use chain if we encounter a variable that we are looking for. If we encounter non-supported construct then we mark that variable as "use" because we haven't completely analyzed the usage. Marking that variable "U" make sures that won't get optimized. Then we distinguish between local and non-local variables. All variables that appear on lhs are marked as "definitions" whereas the one on rhs are marked as "usages".

Definition at line 369 of file defuse_analyze_visitor.cpp.

◆ visit_argument()

void nmodl::visitor::DefUseAnalyzeVisitor::visit_argument ( const ast::Argument & node )

overridevirtual

visit node of type ast::Argument

Detailed Description

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ DefUseAnalyzeVisitor() [1/3]

◆ DefUseAnalyzeVisitor() [2/3]

◆ DefUseAnalyzeVisitor() [3/3]

Member Function Documentation

◆ analyze()

◆ process_variable() [1/2]

◆ process_variable() [2/2]

◆ start_new_chain()

◆ update_defuse_chain()

◆ visit_argument()

◆ visit_binary_expression()

◆ visit_conductance_hint()

◆ visit_conserve()

◆ visit_from_statement()

◆ visit_function_call()

◆ visit_if_statement()

◆ visit_indexed_name()

◆ visit_lin_equation()

◆ visit_local_list_statement()

◆ visit_name()

◆ visit_non_lin_equation()

◆ visit_reaction_statement()

◆ visit_statement_block()

◆ visit_unsupported_node()

◆ visit_var_name()

◆ visit_verbatim()

◆ visit_with_new_chain()

Member Data Documentation

◆ current_binary_expression

◆ current_chain

◆ current_symtab

◆ global_symtab

◆ ignore_verbatim

◆ symtab_stack

◆ unsupported_node

◆ variable_name

◆ variable_type

◆ visiting_lhs