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tune user-pop
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@NikolajBjorner
NikolajBjorner committed Jan 19, 2021
1 parent 3ed490d commit b87405c
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Showing 3 changed files with 114 additions and 126 deletions.
58 changes: 58 additions & 0 deletions src/sat/sat_gc.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -423,6 +423,64 @@ namespace sat {
return true;
}

void solver::gc_vars(bool_var max_var) {
init_visited();
m_aux_literals.reset();
auto gc_watch = [&](literal lit) {
auto& wl1 = get_wlist(lit);
for (auto w : get_wlist(lit)) {
if (w.is_binary_clause() && w.get_literal().var() < max_var && !is_visited(w.get_literal())) {
m_aux_literals.push_back(w.get_literal());
mark_visited(w.get_literal());
}
}
wl1.reset();
};
for (unsigned v = max_var; v < num_vars(); ++v) {
gc_watch(literal(v, false));
gc_watch(literal(v, true));
}

for (literal lit : m_aux_literals) {
auto& wl2 = get_wlist(~lit);
unsigned j = 0;
for (auto w2 : wl2)
if (!w2.is_binary_clause() || w2.get_literal().var() < max_var)
wl2[j++] = w2;
wl2.shrink(j);
}
m_aux_literals.reset();

auto gc_clauses = [&](ptr_vector<clause>& clauses) {
unsigned j = 0;
for (clause* c : clauses) {
bool should_remove = false;
for (auto lit : *c)
should_remove |= lit.var() >= max_var;
if (should_remove) {
SASSERT(!c->on_reinit_stack());
detach_clause(*c);
del_clause(*c);
}
else {
clauses[j++] = c;
}
}
clauses.shrink(j);
};
gc_clauses(m_learned);
gc_clauses(m_clauses);

unsigned j = 0;
for (literal lit : m_trail) {
SASSERT(lvl(lit) == 0);
if (lit.var() < max_var)
m_trail[j++] = lit;
}
m_trail.shrink(j);
shrink_vars(max_var);
}

#if 0
void solver::gc_reinit_stack(unsigned num_scopes) {
SASSERT (!at_base_lvl());
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174 changes: 53 additions & 121 deletions src/sat/sat_solver.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -558,22 +558,27 @@ namespace sat {
m_watches[(~c[0]).index()].push_back(watched(c[1], c[2]));
m_watches[(~c[1]).index()].push_back(watched(c[0], c[2]));
m_watches[(~c[2]).index()].push_back(watched(c[0], c[1]));
if (!at_base_lvl()) {
if (value(c[1]) == l_false && value(c[2]) == l_false) {
m_stats.m_ter_propagate++;
assign(c[0], justification(std::max(lvl(c[1]), lvl(c[2])), c[1], c[2]));
reinit = !c.is_learned();
}
else if (value(c[0]) == l_false && value(c[2]) == l_false) {
m_stats.m_ter_propagate++;
assign(c[1], justification(std::max(lvl(c[0]), lvl(c[2])), c[0], c[2]));
reinit = !c.is_learned();
}
else if (value(c[0]) == l_false && value(c[1]) == l_false) {
m_stats.m_ter_propagate++;
assign(c[2], justification(std::max(lvl(c[0]), lvl(c[1])), c[0], c[1]));
reinit = !c.is_learned();
}
if (!at_base_lvl())
reinit = propagate_ter_clause(c);
return reinit;
}

bool solver::propagate_ter_clause(clause& c) {
bool reinit = false;
if (value(c[1]) == l_false && value(c[2]) == l_false) {
m_stats.m_ter_propagate++;
assign(c[0], justification(std::max(lvl(c[1]), lvl(c[2])), c[1], c[2]));
reinit = !c.is_learned();
}
else if (value(c[0]) == l_false && value(c[2]) == l_false) {
m_stats.m_ter_propagate++;
assign(c[1], justification(std::max(lvl(c[0]), lvl(c[2])), c[0], c[2]));
reinit = !c.is_learned();
}
else if (value(c[0]) == l_false && value(c[1]) == l_false) {
m_stats.m_ter_propagate++;
assign(c[2], justification(std::max(lvl(c[0]), lvl(c[1])), c[0], c[1]));
reinit = !c.is_learned();
}
return reinit;
}
Expand Down Expand Up @@ -3459,8 +3464,8 @@ namespace sat {
}

void solver::pop_vars(unsigned num_scopes) {
integrity_checker check(*this);
check.check_reinit_stack();
//integrity_checker check(*this);
//check.check_reinit_stack();
m_vars_to_reinit.reset();
unsigned old_num_vars = m_vars_lim.pop(num_scopes);
if (old_num_vars == m_active_vars.size())
Expand All @@ -3471,7 +3476,7 @@ namespace sat {

gc_reinit_stack(num_scopes);

check.check_reinit_stack();
// check.check_reinit_stack();
init_visited();
unsigned old_sz = m_scopes[new_lvl].m_clauses_to_reinit_lim;
for (unsigned i = m_clauses_to_reinit.size(); i-- > old_sz; ) {
Expand Down Expand Up @@ -3575,9 +3580,8 @@ namespace sat {
SASSERT(old_sz <= m_trail.size());
SASSERT(m_replay_assign.empty());
unsigned i = m_trail.size();
while (i != old_sz) {
--i;
literal l = m_trail[i];
for (unsigned i = m_trail.size(); i-- > old_sz; ) {
literal l = m_trail[i];
bool_var v = l.var();
if (lvl(v) <= new_lvl) {
m_replay_assign.push_back(l);
Expand Down Expand Up @@ -3618,6 +3622,15 @@ namespace sat {
}
else {
clause & c = *(cw.get_clause());
if (ENABLE_TERNARY && c.size() == 3) {
if (!at_base_lvl() && propagate_ter_clause(c))
m_clauses_to_reinit[j++] = cw;
else if (has_variables_to_reinit(c))
m_clauses_to_reinit[j++] = cw;
else
c.set_reinit_stack(false);
continue;
}
detach_clause(c);
attach_clause(c, reinit);
if (!at_base_lvl() && reinit)
Expand All @@ -3639,118 +3652,37 @@ namespace sat {

void solver::user_push() {
pop_to_base_level();
literal lit;
m_free_var_freeze.push_back(m_free_vars);
m_free_vars.reset(); // resetting free_vars forces new variables to be assigned above new_v
bool_var new_v = mk_var(true, false);
lit = literal(new_v, false);
literal lit = literal(new_v, false);
m_user_scope_literals.push_back(lit);
m_cut_simplifier = nullptr; // for simplicity, wipe it out
if (m_ext)
m_ext->user_push();
TRACE("sat", tout << "user_push: " << lit << "\n";);
}

void solver::gc_lit(clause_vector &clauses, literal lit) {
unsigned j = 0;
for (unsigned i = 0; i < clauses.size(); ++i) {
clause & c = *(clauses[i]);
if (c.contains(lit) || c.contains(~lit)) {
detach_clause(c);
del_clause(c);
}
else {
clauses[j] = &c;
++j;
}
}
clauses.shrink(j);
}

void solver::gc_bin(literal lit) {
bool_var v = lit.var();
for (watch_list& wlist : m_watches) {
watch_list::iterator it = wlist.begin();
watch_list::iterator it2 = wlist.begin();
watch_list::iterator end = wlist.end();
for (; it != end; ++it) {
if (it->is_binary_clause() && it->get_literal().var() == v) {
// skip
}
else {
*it2 = *it;
++it2;
}
}
wlist.set_end(it2);
}
}

bool_var solver::max_var(bool redundant, bool_var v) {
m_user_bin_clauses.reset();
collect_bin_clauses(m_user_bin_clauses, redundant, false);
for (unsigned i = 0; i < m_user_bin_clauses.size(); ++i) {
literal l1 = m_user_bin_clauses[i].first;
literal l2 = m_user_bin_clauses[i].second;
if (l1.var() > v) v = l1.var();
if (l2.var() > v) v = l2.var();
}
return v;
}

bool_var solver::max_var(clause_vector& clauses, bool_var v) {
for (clause* cp : clauses)
for (auto it = cp->begin(), end = cp->end(); it != end; ++it) {
if (it->var() > v)
v = it->var();
}
return v;
}

void solver::gc_var(bool_var v) {
bool_var w = max_var(m_learned, v);
w = max_var(m_clauses, w);
w = max_var(true, w);
w = max_var(false, w);
v = m_mc.max_var(w);
for (literal lit : m_trail) {
w = std::max(w, lit.var());
}
if (m_ext) {
w = m_ext->max_var(w);
}
v = w + 1;

// v is an index of a variable that does not occur in solver state.
if (v < m_justification.size()) {
shrink_vars(v);
}
}

void solver::user_pop(unsigned num_scopes) {
unsigned old_sz = m_user_scope_literals.size() - num_scopes;
bool_var max_var = m_user_scope_literals[old_sz].var();
m_user_scope_literals.shrink(old_sz);

pop_to_base_level();
TRACE("sat", display(tout););
if (m_ext)
m_ext->user_pop(num_scopes);
while (num_scopes > 0) {
literal lit = m_user_scope_literals.back();
m_user_scope_literals.pop_back();
get_wlist(lit).reset();
get_wlist(~lit).reset();

gc_lit(m_learned, lit);
gc_lit(m_clauses, lit);
gc_bin(lit);
TRACE("sat", tout << "gc: " << lit << "\n"; display(tout););
--num_scopes;
for (unsigned i = 0; i < m_trail.size(); ++i) {
if (m_trail[i] == lit) {
TRACE("sat", tout << m_trail << "\n";);
unassign_vars(i, 0);
break;
}
}
gc_var(lit.var());
}

gc_vars(max_var);
TRACE("sat", display(tout););

m_qhead = 0;
unsigned j = 0;
for (bool_var v : m_free_vars)
if (v < max_var)
m_free_vars[j++] = v;
m_free_vars.shrink(j);
m_free_vars.append(m_free_var_freeze[old_sz]);
m_free_var_freeze.shrink(old_sz);
scoped_suspend_rlimit _sp(m_rlimit);
propagate(false);
}
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8 changes: 3 additions & 5 deletions src/sat/sat_solver.h
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Original file line number Diff line number Diff line change
Expand Up @@ -287,6 +287,7 @@ namespace sat {
bool propagate_bin_clause(literal l1, literal l2);
clause * mk_ter_clause(literal * lits, status st);
bool attach_ter_clause(clause & c, status st);
bool propagate_ter_clause(clause& c);
clause * mk_nary_clause(unsigned num_lits, literal * lits, status st);
bool has_variables_to_reinit(clause const& c) const;
bool has_variables_to_reinit(literal l1, literal l2) const;
Expand Down Expand Up @@ -651,14 +652,11 @@ namespace sat {
void reinit_clauses(unsigned old_sz);

literal_vector m_user_scope_literals;
vector<svector<bool_var>> m_free_var_freeze;
literal_vector m_aux_literals;
svector<bin_clause> m_user_bin_clauses;
void gc_lit(clause_vector& clauses, literal lit);
void gc_bin(literal lit);
void gc_var(bool_var v);

bool_var max_var(clause_vector& clauses, bool_var v);
bool_var max_var(bool learned, bool_var v);
void gc_vars(bool_var max_var);

// -----------------------
//
Expand Down

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