void SimplexDecisionProcedure::addRowSgns(sgn_table& sgns, ArithVar basic, int norm){
for(Tableau::RowIterator i = d_tableau.basicRowIterator(basic); !i.atEnd(); ++i){
const Tableau::Entry& entry = *i;
ArithVar v = entry.getColVar();
int sgn = (entry.getCoefficient().sgn());
addSgn(sgns, v, norm * sgn, basic);
}
}
void FCSimplexDecisionProcedure::loadFocusSigns(){
Assert(d_focusCoefficients.empty());
Assert(d_focusErrorVar != ARITHVAR_SENTINEL);
for(Tableau::RowIterator ri = d_tableau.basicRowIterator(d_focusErrorVar); !ri.atEnd(); ++ri){
const Tableau::Entry& e = *ri;
ArithVar curr = e.getColVar();
d_focusCoefficients.set(curr, &e.getCoefficient());
}
}
UpdateInfo FCSimplexDecisionProcedure::selectPrimalUpdate(ArithVar basic, LinearEqualityModule::UpdatePreferenceFunction upf, LinearEqualityModule::VarPreferenceFunction bpf) {
UpdateInfo selected;
static int instance = 0 ;
++instance;
Debug("arith::selectPrimalUpdate")
<< "selectPrimalUpdate " << instance << endl
<< basic << " " << d_tableau.basicRowLength(basic)
<< " " << d_linEq.debugBasicAtBoundCount(basic) << endl;
static const int s_maxCandidatesAfterImprove = 3;
bool isFocus = basic == d_focusErrorVar;
Assert(isFocus || d_errorSet.inError(basic));
int basicDir = isFocus? 1 : d_errorSet.getSgn(basic);
bool dualLike = !isFocus && d_focusSize > 1;
if(!isFocus){
loadFocusSigns();
}
decreasePenalties();
typedef std::vector<Cand> CandVector;
CandVector candidates;
for(Tableau::RowIterator ri = d_tableau.basicRowIterator(basic); !ri.atEnd(); ++ri){
const Tableau::Entry& e = *ri;
ArithVar curr = e.getColVar();
if(curr == basic){ continue; }
int sgn = e.getCoefficient().sgn();
int curr_movement = basicDir * sgn;
bool candidate =
(curr_movement > 0 && d_variables.cmpAssignmentUpperBound(curr) < 0) ||
(curr_movement < 0 && d_variables.cmpAssignmentLowerBound(curr) > 0);
Debug("arith::selectPrimalUpdate")
<< "storing " << basic
<< " " << curr
<< " " << candidate
<< " " << e.getCoefficient()
<< " " << curr_movement
<< " " << focusCoefficient(curr) << endl;
if(!candidate) { continue; }
if(!isFocus){
const Rational& focusC = focusCoefficient(curr);
Assert(dualLike || !focusC.isZero());
if(dualLike && curr_movement != focusC.sgn()){
Debug("arith::selectPrimalUpdate") << "sgn disagreement " << curr << endl;
d_sgnDisagreements.push_back(curr);
continue;
}else{
candidates.push_back(Cand(curr, penalty(curr), curr_movement, &focusC));
}
}else{
candidates.push_back(Cand(curr, penalty(curr), curr_movement, &e.getCoefficient()));
}
}
CompPenaltyColLength colCmp(&d_linEq);
CandVector::iterator i = candidates.begin();
CandVector::iterator end = candidates.end();
std::make_heap(i, end, colCmp);
bool checkEverything = d_pivots == 0;
int candidatesAfterFocusImprove = 0;
while(i != end && (checkEverything || candidatesAfterFocusImprove <= s_maxCandidatesAfterImprove)){
std::pop_heap(i, end, colCmp);
--end;
Cand& cand = (*end);
ArithVar curr = cand.d_nb;
const Rational& coeff = *cand.d_coeff;
LinearEqualityModule::UpdatePreferenceFunction leavingPrefFunc = selectLeavingFunction(curr);
UpdateInfo currProposal = d_linEq.speculativeUpdate(curr, coeff, leavingPrefFunc);
Debug("arith::selectPrimalUpdate")
<< "selected " << selected << endl
<< "currProp " << currProposal << endl
<< "coeff " << coeff << endl;
Assert(!currProposal.uninitialized());
if(candidatesAfterFocusImprove > 0){
candidatesAfterFocusImprove++;
}
if(selected.uninitialized() || (d_linEq.*upf)(selected, currProposal)){
selected = currProposal;
WitnessImprovement w = selected.getWitness(false);
Debug("arith::selectPrimalUpdate") << "selected " << w << endl;
setPenalty(curr, w);
if(improvement(w)){
bool exitEarly;
switch(w){
case ConflictFound: exitEarly = true; break;
case ErrorDropped:
if(checkEverything){
exitEarly = d_errorSize + selected.errorsChange() == 0;
Debug("arith::selectPrimalUpdate")
<< "ee " << d_errorSize << " "
<< selected.errorsChange() << " "
<< d_errorSize + selected.errorsChange() << endl;
}else{
exitEarly = true;
}
break;
case FocusImproved:
candidatesAfterFocusImprove = 1;
exitEarly = false;
break;
default:
exitEarly = false; break;
}
if(exitEarly){ break; }
}
}else{
Debug("arith::selectPrimalUpdate") << "dropped "<< endl;
}
}
if(!isFocus){
unloadFocusSigns();
}
return selected;
}