static inline bool enqueue(solver* s, lit l, clause* from)
{
lbool* values = s->assigns;
int v = lit_var(l);
lbool val = values[v];
lbool sig;
#ifdef VERBOSEDEBUG
printf(L_IND"enqueue("L_LIT")\n", L_ind, L_lit(l));
#endif
/* lbool */ sig = !lit_sign(l); sig += sig - 1;
if (val != l_Undef){
return val == sig;
}else{
/* New fact -- store it. */
int* levels;
clause** reasons;
#ifdef VERBOSEDEBUG
printf(L_IND"bind("L_LIT")\n", L_ind, L_lit(l));
#endif
/* int* */ levels = s->levels;
/* clause** */ reasons = s->reasons;
values [v] = sig;
levels [v] = solver_dlevel(s);
reasons[v] = from;
s->trail[s->qtail++] = l;
order_assigned(s, v);
return true;
}
}
static inline void assume(solver* s, lit l){
assert(s->qtail == s->qhead);
assert(s->assigns[lit_var(l)] == l_Undef);
#ifdef VERBOSEDEBUG
printf(L_IND"assume("L_LIT")\n", L_ind, L_lit(l));
#endif
veci_push(&s->trail_lim,s->qtail);
enqueue(s,l,(clause*)0);
}
static void printlits(lit* begin, lit* end)
{
int i;
for (i = 0; i < end - begin; i++)
printf(L_LIT" ",L_lit(begin[i]));
}
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
}
