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more caching in MakeScalProd, adds small filters to MinConstraint::LeafChanged and MaxConstraint::LeafChanged to avoid calling PushUp

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lperron@google.com
2013-08-01 23:38:44 +00:00
parent 7d4868e07f
commit fd013b575b
1 changed files with 22 additions and 20 deletions
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42
src/constraint_solver/expr_array.cc
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@@ -605,7 +605,16 @@ class MinConstraint : public TreeArrayConstraint {
void LeafChanged(int term_index) {
IntVar* const var = vars_[term_index];
SetRange(MaxDepth(), term_index, var->Min(), var->Max());
PushUp(term_index);
const int parent_depth = MaxDepth() - 1;
const int parent = Parent(term_index);
const int64 old_min = var->OldMin();
const int64 var_min = var->Min();
const int64 var_max = var->Max();
if ((old_min == Min(parent_depth, parent) && old_min != var_min) ||
var_max < Max(parent_depth, parent)) {
// Can influence the parent bounds.
PushUp(term_index);
}
}
void PushUp(int position) {
@@ -750,7 +759,16 @@ class MaxConstraint : public TreeArrayConstraint {
void LeafChanged(int term_index) {
IntVar* const var = vars_[term_index];
SetRange(MaxDepth(), term_index, var->Min(), var->Max());
PushUp(term_index);
const int parent_depth = MaxDepth() - 1;
const int parent = Parent(term_index);
const int64 old_max = var->OldMax();
const int64 var_min = var->Min();
const int64 var_max = var->Max();
if ((old_max == Max(parent_depth, parent) && old_max != var_max) ||
var_min > Min(parent_depth, parent)) {
// Can influence the parent bounds.
PushUp(term_index);
}
}
void PushUp(int position) {
@@ -2694,7 +2712,7 @@ IntExpr* MakeSumArrayAux(Solver* const solver,
IntExpr* const cache = solver->Cache()->FindVarArrayExpression(
vars, ModelCache::VAR_ARRAY_SUM);
if (cache != NULL) {
return cache;
return solver()->MakeSum(cache, constant);
} else {
const string name =
StringPrintf("Sum([%s])", NameVector(vars, ", ").c_str());
@@ -2789,23 +2807,7 @@ IntExpr* MakeScalProdAux(Solver* solver, const std::vector<IntVar*>& vars,
for (int i = 0; i < size; ++i) {
terms.push_back(solver->MakeProd(vars[i], coefs[i])->Var());
}
int64 new_min = 0;
int64 new_max = 0;
for (int i = 0; i < size; ++i) {
if (new_min != kint64min) {
new_min = CapAdd(terms[i]->Min(), new_min);
}
if (new_max != kint64max) {
new_max = CapAdd(terms[i]->Max(), new_max);
}
}
const string name =
StringPrintf("ScalProd([%s], [%s])", NameVector(vars, ", ").c_str(),
Int64VectorToString(coefs, ", ").c_str());
IntVar* const scal_prod_var = solver->MakeIntVar(new_min, new_max, name);
solver->AddConstraint(
solver->RevAlloc(new SumConstraint(solver, terms, scal_prod_var)));
return solver->MakeSum(scal_prod_var, constant);
return MakeSumArrayAux(solver, terms, constant);
}
template <class T>