sdfg::symbolic::maps Namespace Reference

Classes
struct	DependenceDeltas
	Represents the set of dependence distance vectors between two access patterns. More...

Functions
bool	is_monotonic (const Expression expr, const Symbol sym, const Assumptions &assums)
	Checks if an expression is monotonic with respect to a symbol.
bool	intersects (const MultiExpression &expr1, const MultiExpression &expr2, const Symbol indvar, const Assumptions &assums1, const Assumptions &assums2)
	Checks if the integer domain of two maps intersect.
DependenceDeltas	dependence_deltas (const MultiExpression &expr1, const MultiExpression &expr2, const Symbol indvar, const Assumptions &assums1, const Assumptions &assums2)
	Computes the dependence distance delta set between two access patterns.
DependenceDeltas	dependence_deltas (const MultiExpression &expr1, const MultiExpression &expr2, const Symbol indvar, sdfg::symbolic::AssumptionsBounds &bounds1, sdfg::symbolic::AssumptionsBounds &bounds2)
	Same as dependence_deltas, but reuses caller-supplied AssumptionsBounds.

Function Documentation

dependence_deltas() [1/2]

DependenceDeltas sdfg::symbolic::maps::dependence_deltas	(	const MultiExpression &	expr1,
		const MultiExpression &	expr2,
		const Symbol	indvar,
		const Assumptions &	assums1,
		const Assumptions &	assums2 )

Computes the dependence distance delta set between two access patterns.

Returns a DependenceDeltas struct containing the full ISL delta set representing all possible iteration-distance vectors between aliasing pairs of the two expressions. The dimensions correspond to all non-constant symbols (induction variables).

If the accesses are provably disjoint (via monotonicity or ISL analysis), returns an empty delta set.

dependence_deltas() [2/2]

DependenceDeltas sdfg::symbolic::maps::dependence_deltas	(	const MultiExpression &	expr1,
		const MultiExpression &	expr2,
		const Symbol	indvar,
		sdfg::symbolic::AssumptionsBounds &	bounds1,
		sdfg::symbolic::AssumptionsBounds &	bounds2 )

Same as dependence_deltas, but reuses caller-supplied AssumptionsBounds.

intersects()

bool sdfg::symbolic::maps::intersects	(	const MultiExpression &	expr1,
		const MultiExpression &	expr2,
		const Symbol	indvar,
		const Assumptions &	assums1,
		const Assumptions &	assums2 )

Checks if the integer domain of two maps intersect.

Parameters

expr1	First multi-dimensional expression (e.g., memory access pattern)
expr2	Second multi-dimensional expression
indvar	The induction variable that evolves
assums1	Assumptions for the first expression including evolution maps
assums2	Assumptions for the second expression including evolution maps

Returns

true if the integer domains of expr1 and expr2 can overlap

// Check if A[i] and A[j+5] intersect when both evolve 0 to 10
auto i = symbolic::symbol("i");
auto j = symbolic::symbol("j");
MultiExpression expr1 = {i};
MultiExpression expr2 = {symbolic::add(j, symbolic::integer(5))};
 
Assumptions assums1, assums2;
assums1[i].add_lower_bound(symbolic::zero());
assums1[i].add_upper_bound(symbolic::integer(10));
assums2[j].add_lower_bound(symbolic::zero());
assums2[j].add_upper_bound(symbolic::integer(10));
 
bool overlap = intersects(expr1, expr2, i, assums1, assums2);  // true (e.g., i=7, j=2)

is_monotonic()

bool sdfg::symbolic::maps::is_monotonic	(	const Expression	expr,
		const Symbol	sym,
		const Assumptions &	assums )

Checks if an expression is monotonic with respect to a symbol.

Parameters

expr	The expression to check
sym	The symbol to check monotonicity with respect to
assums	Assumptions about symbols including the evolution map

Returns

true if expr is monotonic (always increasing or always decreasing) as sym evolves

An expression is monotonic if it consistently increases as the symbol evolves.