souffle::ast::SipsMetric Class Reference

Class for SIPS cost-metric functions Each subclass represents a different heuristic used for evaluating the cost of choosing an atom next in the schedule. More...

#include <SipsMetric.h>

Inheritance diagram for souffle::ast::SipsMetric:

Collaboration diagram for souffle::ast::SipsMetric:

Public Member Functions
std::vector< unsigned int >	getReordering (const Clause *clause) const
	Determines the new ordering of a clause after the SIPS is applied. More...
virtual	~SipsMetric ()=default

Static Public Member Functions
static std::unique_ptr< SipsMetric >	create (const std::string &heuristic, const TranslationUnit &tu)
	Create a SIPS metric based on a given heuristic. More...

Protected Member Functions
virtual std::vector< double >	evaluateCosts (const std::vector< Atom * > atoms, const BindingStore &bindingStore) const =0
	Evaluates the cost of choosing each atom next in the current schedule. More...

Detailed Description

Class for SIPS cost-metric functions Each subclass represents a different heuristic used for evaluating the cost of choosing an atom next in the schedule.

Definition at line 39 of file SipsMetric.h.

Constructor & Destructor Documentation

~SipsMetric()

virtual souffle::ast::SipsMetric::~SipsMetric ( )

virtualdefault

Member Function Documentation

create()

std::unique_ptr< SipsMetric > souffle::ast::SipsMetric::create ( const std::string &  heuristic, const TranslationUnit &  tu  )

static

Create a SIPS metric based on a given heuristic.

Definition at line 68 of file SipsMetric.cpp.

                                                                   {
    // Goal: Always choose the left-most atom
    std::vector<double> cost;
    for (const auto* atom : atoms) {

evaluateCosts()

virtual std::vector<double> souffle::ast::SipsMetric::evaluateCosts ( const std::vector< Atom * >  atoms, const BindingStore &  bindingStore  ) const

protectedpure virtual

Evaluates the cost of choosing each atom next in the current schedule.

Parameters

atoms	atoms to choose from; may be nullptr
bindingStore	the variables already bound to a value

Implemented in souffle::ast::DeltaInputSips, souffle::ast::InputSips, souffle::ast::DeltaSips, souffle::ast::ProfileUseSips, souffle::ast::LeastFreeVarsSips, souffle::ast::LeastFreeSips, souffle::ast::MaxRatioSips, souffle::ast::MaxBoundSips, souffle::ast::NaiveSips, souffle::ast::AllBoundSips, and souffle::ast::StrictSips.

Referenced by getReordering().

getReordering()

std::vector< unsigned int > souffle::ast::SipsMetric::getReordering

(

const Clause *

clause

)

const

Determines the new ordering of a clause after the SIPS is applied.

Parameters

clause

clause to reorder

Returns

the vector of new positions; v[i] = j iff atom j moves to pos i

Definition at line 39 of file SipsMetric.cpp.

                                    {
        // grab the index of the next atom, based on the SIPS function
        const auto& costs = evaluateCosts(atoms, bindingStore);
        auto minIdx = std::distance(costs.begin(), std::min_element(costs.begin(), costs.end()));
        const auto* nextAtom = atoms[minIdx];
        assert(nextAtom != nullptr && "nullptr atoms should have maximal cost");
 
        // set all arguments that are variables as bound
        for (const auto* arg : nextAtom->getArguments()) {
            if (const auto* var = dynamic_cast<const Variable*>(arg)) {
                bindingStore.bindVariableStrongly(var->getName());
            }
        }
 
        newOrder[numAdded] = minIdx;  // add to the ordering
        atoms[minIdx] = nullptr;      // mark as done
        numAdded++;                   // move on
    }
 
    return newOrder;
}
 
/** Create a SIPS metric based on a given heuristic. */
std::unique_ptr<SipsMetric> SipsMetric::create(const std::string& heuristic, const TranslationUnit& tu) {
    if (heuristic == "strict")
        return std::make_unique<StrictSips>();
    else if (heuristic == "all-bound")

References evaluateCosts().

Here is the call graph for this function:

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

• ast/utility/SipsMetric.h
• ast/utility/SipsMetric.cpp