void solver_reducedb(solver* s)
{
int i, j;
double extra_lim = s->cla_inc / vecp_size(&s->learnts);
/* Remove any clause below this activity */
clause** learnts = (clause**)vecp_begin(&s->learnts);
clause** reasons = s->reasons;
sort(vecp_begin(&s->learnts), vecp_size(&s->learnts), clause_cmp);
for (i = j = 0; i < vecp_size(&s->learnts) / 2; i++){
if (clause_size(learnts[i]) > 2
&& reasons[lit_var(*clause_begin(learnts[i]))]
!= learnts[i])
clause_remove(s,learnts[i]);
else
learnts[j++] = learnts[i];
}
for (; i < vecp_size(&s->learnts); i++){
if (clause_size(learnts[i]) > 2
&& reasons[lit_var(*clause_begin(learnts[i]))]
!= learnts[i]
&& clause_activity(learnts[i]) < extra_lim)
clause_remove(s,learnts[i]);
else
learnts[j++] = learnts[i];
}
/* printf("reducedb deleted %d\n", vecp_size(&s->learnts) - j); */
vecp_resize(&s->learnts,j);
}
bool IfStmt::isEqualTo(ShPtr<Value> otherValue) const {
// The types of compared instances have to match.
ShPtr<IfStmt> otherIfStmt = cast<IfStmt>(otherValue);
if (!otherIfStmt) {
return false;
}
// The number of 'if' clauses have to match.
if (ifClauseList.size() != otherIfStmt->ifClauseList.size()) {
return false;
}
// All 'if' clauses have to match.
for (auto i = clause_begin(), j = otherIfStmt->clause_begin(),
e = clause_end(); i != e; ++i, ++j) {
if (!(i->first->isEqualTo(j->first) &&
i->second->isEqualTo(j->second))) {
return false;
}
}
// The else clauses have to match.
if (hasElseClause()) {
return otherIfStmt->hasElseClause() &&
elseClause->isEqualTo(otherIfStmt->elseClause);
}
// The first if statement doesn't have an else clause, so the other if
// statement should also not have one.
return !otherIfStmt->hasElseClause();
}
static void clause_remove(solver* s, clause* c)
{
lit* lits = clause_begin(c);
assert(lit_neg(lits[0]) < s->size*2);
assert(lit_neg(lits[1]) < s->size*2);
/* vecp_remove(solver_read_wlist(s,lit_neg(lits[0])),(void*)c); */
/* vecp_remove(solver_read_wlist(s,lit_neg(lits[1])),(void*)c); */
assert(lits[0] < s->size*2);
vecp_remove(solver_read_wlist(s,lit_neg(lits[0])),
(void*)(clause_size(c) > 2 ? c : clause_from_lit(lits[1])));
vecp_remove(solver_read_wlist(s,lit_neg(lits[1])),
(void*)(clause_size(c) > 2 ? c : clause_from_lit(lits[0])));
if (clause_learnt(c)){
s->stats.learnts--;
s->stats.learnts_literals -= clause_size(c);
}else{
s->stats.clauses--;
s->stats.clauses_literals -= clause_size(c);
}
free(c);
}
static lbool clause_simplify(solver* s, clause* c)
{
lit* lits = clause_begin(c);
lbool* values = s->assigns;
int i;
assert(solver_dlevel(s) == 0);
for (i = 0; i < clause_size(c); i++){
lbool sig = !lit_sign(lits[i]); sig += sig - 1;
if (values[lit_var(lits[i])] == sig)
return l_True;
}
return l_False;
}
bool solver_simplify(solver* s)
{
clause** reasons;
int type;
assert(solver_dlevel(s) == 0);
if (solver_propagate(s) != 0)
return false;
if (s->qhead == s->simpdb_assigns || s->simpdb_props > 0)
return true;
reasons = s->reasons;
for (type = 0; type < 2; type++){
vecp* cs = type ? &s->learnts : &s->clauses;
clause** cls = (clause**)vecp_begin(cs);
int i, j;
for (j = i = 0; i < vecp_size(cs); i++){
if (reasons[lit_var(*clause_begin(cls[i]))] != cls[i] &&
clause_simplify(s,cls[i]) == l_True)
clause_remove(s,cls[i]);
else
cls[j++] = cls[i];
}
vecp_resize(cs,j);
}
s->simpdb_assigns = s->qhead;
/* (shouldn't depend on 'stats' really, but it will do for now) */
s->simpdb_props = (int)(s->stats.clauses_literals
+ s->stats.learnts_literals);
return true;
}
/**
* @brief Returns the body of the first if clause in the statement.
*
* If there are no if clauses, the null pointer is returned.
*/
ShPtr<Statement> IfStmt::getFirstIfBody() const {
if (ifClauseList.empty()) {
return ShPtr<Statement>();
}
return clause_begin()->second;
}
/**
* @brief Returns the condition of the first if clause in the statement.
*
* If there are no if clauses, the null pointer is returned.
*/
ShPtr<Expression> IfStmt::getFirstIfCond() const {
if (ifClauseList.empty()) {
return ShPtr<Expression>();
}
return clause_begin()->first;
}
clause* solver_propagate(solver* s)
{
lbool* values = s->assigns;
clause* confl = (clause*)0;
lit* lits;
/* printf("solver_propagate\n"); */
while (confl == 0 && s->qtail - s->qhead > 0){
lit p = s->trail[s->qhead++];
vecp* ws = solver_read_wlist(s,p);
clause **begin = (clause**)vecp_begin(ws);
clause **end = begin + vecp_size(ws);
clause **i, **j;
s->stats.propagations++;
s->simpdb_props--;
/* printf("checking lit %d: "L_LIT"\n", veci_size(ws),
L_lit(p)); */
for (i = j = begin; i < end; ){
if (clause_is_lit(*i)){
*j++ = *i;
if (!enqueue(s,clause_read_lit(*i),clause_from_lit(p))){
confl = s->binary;
(clause_begin(confl))[1] = lit_neg(p);
(clause_begin(confl))[0] = clause_read_lit(*i++);
/* Copy the remaining watches: */
while (i < end)
*j++ = *i++;
}
}else{
lit false_lit;
lbool sig;
lits = clause_begin(*i);
/* Make sure the false literal is data[1]: */
false_lit = lit_neg(p);
if (lits[0] == false_lit){
lits[0] = lits[1];
lits[1] = false_lit;
}
assert(lits[1] == false_lit);
/* printf("checking clause: ");
printlits(lits, lits+clause_size(*i));
printf("\n"); */
/* If 0th watch is true, then clause is already
satisfied. */
sig = !lit_sign(lits[0]); sig += sig - 1;
if (values[lit_var(lits[0])] == sig){
*j++ = *i;
}else{
/* Look for new watch: */
lit* stop = lits + clause_size(*i);
lit* k;
for (k = lits + 2; k < stop; k++){
lbool sig = lit_sign(*k); sig += sig - 1;
if (values[lit_var(*k)] != sig){
lits[1] = *k;
*k = false_lit;
vecp_push(solver_read_wlist(s,
lit_neg(lits[1])),*i);
goto next; }
}
*j++ = *i;
/* Clause is unit under assignment: */
if (!enqueue(s,lits[0], *i)){
confl = *i++;
/* Copy the remaining watches: */
while (i < end)
*j++ = *i++;
}
}
}
next:
i++;
}
s->stats.inspects += j - (clause**)vecp_begin(ws);
vecp_resize(ws,j - (clause**)vecp_begin(ws));
}
return confl;
}
static void solver_analyze(solver* s, clause* c, veci* learnt)
{
lit* trail = s->trail;
lbool* tags = s->tags;
clause** reasons = s->reasons;
int* levels = s->levels;
int cnt = 0;
lit p = lit_Undef;
int ind = s->qtail-1;
lit* lits;
int i, j, minl;
int* tagged;
veci_push(learnt,lit_Undef);
do{
assert(c != 0);
if (clause_is_lit(c)){
lit q = clause_read_lit(c);
assert(lit_var(q) >= 0 && lit_var(q) < s->size);
if (tags[lit_var(q)] == l_Undef && levels[lit_var(q)] > 0){
tags[lit_var(q)] = l_True;
veci_push(&s->tagged,lit_var(q));
act_var_bump(s,lit_var(q));
if (levels[lit_var(q)] == solver_dlevel(s))
cnt++;
else
veci_push(learnt,q);
}
}else{
if (clause_learnt(c))
act_clause_bump(s,c);
lits = clause_begin(c);
/* printlits(lits,lits+clause_size(c)); printf("\n"); */
for (j = (p == lit_Undef ? 0 : 1); j < clause_size(c); j++){
lit q = lits[j];
assert(lit_var(q) >= 0 && lit_var(q) < s->size);
if (tags[lit_var(q)] == l_Undef
&& levels[lit_var(q)] > 0){
tags[lit_var(q)] = l_True;
veci_push(&s->tagged,lit_var(q));
act_var_bump(s,lit_var(q));
if (levels[lit_var(q)] == solver_dlevel(s))
cnt++;
else
veci_push(learnt,q);
}
}
}
while (tags[lit_var(trail[ind--])] == l_Undef);
p = trail[ind+1];
c = reasons[lit_var(p)];
cnt--;
}while (cnt > 0);
*veci_begin(learnt) = lit_neg(p);
lits = veci_begin(learnt);
minl = 0;
for (i = 1; i < veci_size(learnt); i++){
int lev = levels[lit_var(lits[i])];
minl |= 1 << (lev & 31);
}
/* simplify (full) */
for (i = j = 1; i < veci_size(learnt); i++){
if (reasons[lit_var(lits[i])] == 0
|| !solver_lit_removable(s,lits[i],minl))
lits[j++] = lits[i];
}
/* update size of learnt + statistics */
s->stats.max_literals += veci_size(learnt);
veci_resize(learnt,j);
s->stats.tot_literals += j;
/* clear tags */
tagged = veci_begin(&s->tagged);
for (i = 0; i < veci_size(&s->tagged); i++)
tags[tagged[i]] = l_Undef;
veci_resize(&s->tagged,0);
#ifdef DEBUG
for (i = 0; i < s->size; i++)
assert(tags[i] == l_Undef);
#endif
#ifdef VERBOSEDEBUG
printf(L_IND"Learnt {", L_ind);
for (i = 0; i < veci_size(learnt); i++)
printf(" "L_LIT, L_lit(lits[i]));
#endif
if (veci_size(learnt) > 1){
int max_i = 1;
int max = levels[lit_var(lits[1])];
lit tmp;
for (i = 2; i < veci_size(learnt); i++)
if (levels[lit_var(lits[i])] > max){
max = levels[lit_var(lits[i])];
max_i = i;
}
tmp = lits[1];
lits[1] = lits[max_i];
lits[max_i] = tmp;
}
#ifdef VERBOSEDEBUG
{
int lev = veci_size(learnt) > 1 ? levels[lit_var(lits[1])] : 0;
printf(" } at level %d\n", lev);
}
#endif
}
static bool solver_lit_removable(solver* s, lit l, int minl)
{
lbool* tags = s->tags;
clause** reasons = s->reasons;
int* levels = s->levels;
int top = veci_size(&s->tagged);
assert(lit_var(l) >= 0 && lit_var(l) < s->size);
assert(reasons[lit_var(l)] != 0);
veci_resize(&s->stack,0);
veci_push(&s->stack,lit_var(l));
while (veci_size(&s->stack) > 0){
clause* c;
int v = veci_begin(&s->stack)[veci_size(&s->stack)-1];
assert(v >= 0 && v < s->size);
veci_resize(&s->stack,veci_size(&s->stack)-1);
assert(reasons[v] != 0);
c = reasons[v];
if (clause_is_lit(c)){
int v = lit_var(clause_read_lit(c));
if (tags[v] == l_Undef && levels[v] != 0){
if (reasons[v] != 0
&& ((1 << (levels[v] & 31)) & minl)){
veci_push(&s->stack,v);
tags[v] = l_True;
veci_push(&s->tagged,v);
}else{
int* tagged = veci_begin(&s->tagged);
int j;
for (j = top; j < veci_size(&s->tagged); j++)
tags[tagged[j]] = l_Undef;
veci_resize(&s->tagged,top);
return false;
}
}
}else{
lit* lits = clause_begin(c);
int i, j;
for (i = 1; i < clause_size(c); i++){
int v = lit_var(lits[i]);
if (tags[v] == l_Undef && levels[v] != 0){
if (reasons[v] != 0
&& ((1 << (levels[v] & 31)) & minl)){
veci_push(&s->stack,lit_var(lits[i]));
tags[v] = l_True;
veci_push(&s->tagged,v);
}else{
int* tagged = veci_begin(&s->tagged);
for (j = top; j < veci_size(&s->tagged); j++)
tags[tagged[j]] = l_Undef;
veci_resize(&s->tagged,top);
return false;
}
}
}
}
}
return true;
}
