sdfg::control_flow::InterstateEdge Class Reference

An edge connecting two states in an SDFG control-flow graph. More...

#include <sdfg/control_flow/interstate_edge.h>

Inheritance diagram for sdfg::control_flow::InterstateEdge:

Public Member Functions
	InterstateEdge (const InterstateEdge &state)=delete
InterstateEdge &	operator= (const InterstateEdge &)=delete
ElementType	type_id () const override
	Returns the type of the element.
void	validate (const Function &function) const override
	Validates the interstate edge within the context of a function.
const graph::Edge	edge () const
	Returns the graph edge representing this interstate edge.
const control_flow::State &	src () const
	Returns the source state of this edge.
const control_flow::State &	dst () const
	Returns the destination state of this edge.
const symbolic::Condition	condition () const
	Returns the condition guarding this transition.
bool	is_unconditional () const
	Checks if this edge represents an unconditional transition.
const control_flow::Assignments &	assignments () const
	Returns the symbol assignments for this edge.
void	replace (const symbolic::Expression old_expression, const symbolic::Expression new_expression) override
	Replaces symbolic expressions in the edge's condition and assignments.
Public Member Functions inherited from sdfg::Element
	Element (size_t element_id, const DebugInfo &debug_info)
virtual	~Element ()=default
size_t	element_id () const
const DebugInfo &	debug_info () const
void	set_debug_info (const DebugInfo &debug_info)
void	add_metadata (const std::string &key, const std::string &value)
void	remove_metadata (const std::string &key)
const std::string &	metadata (const std::string &key) const
const std::string *	metadata_if_exists (const std::string &key) const
const std::unordered_map< std::string, std::string > &	metadata () const
std::string_view	element_type () const
	Returns the type of the element as a human-readable string.
virtual void	replace (const symbolic::ExpressionMapping &replacements)

Static Public Member Functions
static bool	classof (const Element &element)

Friends
class	builder::SDFGBuilder

Additional Inherited Members
Protected Attributes inherited from sdfg::Element
size_t	element_id_
DebugInfo	debug_info_
std::unordered_map< std::string, std::string >	metadata_

Detailed Description

An edge connecting two states in an SDFG control-flow graph.

InterstateEdge represents a transition between states in a Stateful DataFlow Graph. Each edge can have:

• A condition: A boolean expression that guards the transition
• Assignments: Updates to symbols that occur during the transition

Execution Semantics

IMPORTANT: When an interstate edge is traversed, the execution order is:

1. First, the condition is evaluated using the current symbol values
2. Then, if the condition is true, the assignments are executed to update symbols
3. Finally, control transfers to the destination state

This means:

• The condition sees symbol values BEFORE any assignments on this edge
• Assignments cannot affect the condition evaluation on the same edge
• Assignments affect symbol values for subsequent edges and states

Examples

// Example 1: Loop counter increment
// Condition uses current value of i, then i is incremented
symbolic::Symbol i = symbolic::symbol("i");
auto condition = symbolic::Lt(i, symbolic::integer(10));  // Check i < 10
Assignments assignments;
assignments[i] = symbolic::add(i, symbolic::integer(1));  // Then i = i + 1
 
// Example 2: Unconditional transition with assignment
auto condition = symbolic::__true__();
Assignments assignments2;
assignments2[i] = symbolic::integer(0);  // Initialize i = 0

See also

State for the source and destination of transitions

symbolic::Condition for the condition expressions

Constructor & Destructor Documentation

InterstateEdge()

sdfg::control_flow::InterstateEdge::InterstateEdge ( const InterstateEdge & state )

delete

Member Function Documentation

assignments()

const control_flow::Assignments & sdfg::control_flow::InterstateEdge::assignments

(

)

const

Returns the symbol assignments for this edge.

Assignments are executed AFTER the condition is evaluated and found to be true. The assignments update symbol values that will be visible in the destination state and subsequent edges.

Returns

Map of symbols to their assigned expressions

classof()

bool sdfg::control_flow::InterstateEdge::classof ( const Element & element )

inlinestatic

condition()

const symbolic::Condition sdfg::control_flow::InterstateEdge::condition

(

)

const

Returns the condition guarding this transition.

The condition is evaluated BEFORE any assignments are executed. The condition uses the symbol values as they exist when entering the edge.

Returns

The boolean condition expression

See also

is_unconditional() to check if this is an unconditional transition

dst()

const control_flow::State & sdfg::control_flow::InterstateEdge::dst

(

)

const

Returns the destination state of this edge.

Returns

Reference to the destination state

edge()

const graph::Edge sdfg::control_flow::InterstateEdge::edge

(

)

const

Returns the graph edge representing this interstate edge.

Returns

The graph edge

is_unconditional()

bool sdfg::control_flow::InterstateEdge::is_unconditional

(

)

const

Checks if this edge represents an unconditional transition.

Returns

true if the condition is always true, false otherwise

operator=()

InterstateEdge & sdfg::control_flow::InterstateEdge::operator= ( const InterstateEdge & )

delete

replace()

void sdfg::control_flow::InterstateEdge::replace ( const symbolic::Expression old_expression, const symbolic::Expression new_expression )

overridevirtual

Replaces symbolic expressions in the edge's condition and assignments.

Parameters

old_expression	The expression to replace
new_expression	The replacement expression

Implements sdfg::Element.

src()

const control_flow::State & sdfg::control_flow::InterstateEdge::src

(

)

const

Returns the source state of this edge.

Returns

Reference to the source state

type_id()

ElementType sdfg::control_flow::InterstateEdge::type_id ( ) const

inlineoverridevirtual

Returns the type of the element.

Implements sdfg::Element.

validate()

void sdfg::control_flow::InterstateEdge::validate ( const Function & function ) const

overridevirtual

Validates the interstate edge within the context of a function.

Validates that:

• The condition is a valid boolean expression
• All symbols in the condition and assignments are properly typed
• Assignment targets are integer scalar types
• Assignment sources evaluate to integer or pointer types

Parameters

function

The function containing this edge

Exceptions

InvalidSDFGException

if validation fails

Implements sdfg::Element.

Friends And Related Symbol Documentation

builder::SDFGBuilder

friend class builder::SDFGBuilder

friend

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

• sdfg/include/sdfg/control_flow/interstate_edge.h