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add circuit and unate encoding besides sorting option

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-07-06 21:09:13 -07:00
parent 0b30ddb769
commit 3ae0ea8246
8 changed files with 488 additions and 184 deletions
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60
src/sat/ba_solver.cpp
View file

@ -2591,22 +2591,54 @@ namespace sat {
return literal(v, false);
}
literal ba_solver::ba_sort::mk_max(literal l1, literal l2) {
VERIFY(l1 != null_literal);
VERIFY(l2 != null_literal);
if (l1 == m_true) return l1;
if (l2 == m_true) return l2;
if (l1 == ~m_true) return l2;
if (l2 == ~m_true) return l1;
literal max = fresh("max");
s.s().mk_clause(~l1, max);
s.s().mk_clause(~l2, max);
s.s().mk_clause(~max, l1, l2);
return max;
literal ba_solver::ba_sort::mk_max(unsigned n, literal const* lits) {
m_lits.reset();
for (unsigned i = 0; i < n; ++i) {
if (lits[i] == m_true) return m_true;
if (lits[i] == ~m_true) continue;
m_lits.push_back(lits[i]);
}
switch (m_lits.size()) {
case 0:
return ~m_true;
case 1:
return m_lits[0];
default: {
literal max = fresh("max");
for (unsigned i = 0; i < n; ++i) {
s.s().mk_clause(~m_lits[i], max);
}
m_lits.push_back(~max);
s.s().mk_clause(m_lits.size(), m_lits.c_ptr());
return max;
}
}
}
literal ba_solver::ba_sort::mk_min(literal l1, literal l2) {
return ~mk_max(~l1, ~l2);
literal ba_solver::ba_sort::mk_min(unsigned n, literal const* lits) {
m_lits.reset();
for (unsigned i = 0; i < n; ++i) {
if (lits[i] == ~m_true) return ~m_true;
if (lits[i] == m_true) continue;
m_lits.push_back(lits[i]);
}
switch (m_lits.size()) {
case 0:
return m_true;
case 1:
return m_lits[0];
default: {
literal min = fresh("min");
for (unsigned i = 0; i < n; ++i) {
s.s().mk_clause(~min, m_lits[i]);
m_lits[i] = ~m_lits[i];
}
m_lits.push_back(min);
s.s().mk_clause(m_lits.size(), m_lits.c_ptr());
return min;
}
}
}
void ba_solver::ba_sort::mk_clause(unsigned n, literal const* lits) {

4
src/sat/ba_solver.h
View file

@ -255,8 +255,8 @@ namespace sat {
pliteral mk_true();
pliteral mk_not(pliteral l);
pliteral fresh(char const*);
pliteral mk_max(pliteral l1, pliteral l2);
pliteral mk_min(pliteral l1, pliteral l2);
pliteral mk_min(unsigned, pliteral const* lits);
pliteral mk_max(unsigned, pliteral const* lits);
void mk_clause(unsigned n, literal const* lits);
std::ostream& pp(std::ostream& out, pliteral l) const;
};

2
src/sat/sat_params.pyg
View file

@ -43,7 +43,7 @@ def_module_params('sat',
('cardinality.solver', BOOL, True, 'use cardinality solver'),
('pb.solver', SYMBOL, 'solver', 'method for handling Pseudo-Boolean constraints: circuit (arithmetical circuit), sorting (sorting circuit), totalizer (use totalizer encoding), solver (use native solver)'),
('xor.solver', BOOL, False, 'use xor solver'),
('atmost1_encoding', SYMBOL, 'grouped', 'encoding used for at-most-1 constraints grouped, bimander, ordered'),
('cardinality.encoding', SYMBOL, 'grouped', 'encoding used for at-most-1 constraints grouped, bimander, ordered, unate, circuit'),
('local_search', BOOL, False, 'use local search instead of CDCL'),
('local_search_threads', UINT, 0, 'number of local search threads to find satisfiable solution'),
('local_search_mode', SYMBOL, 'wsat', 'local search algorithm, either default wsat or qsat'),