mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-04-30 04:15:51 +00:00
Code Activity

remove ternary clause optimization

Browse source 
Removing ternary clause optimization from sat_solver simplifies special case handling of ternary clauses throughout the sat solver and dependent solvers (pb_solver). Benchmarking on QF_BV suggests the ternary clause optimization does not have any effect. While removing ternary clause optimization two bugs in unit propagation were also uncovered: it missed propagations when the only a single undef literal remained in the non-watched literals and it did not update blocked literals in cases where it could in the watch list. These performance bugs were for general clauses, ternary clause propagation did not miss propagations (and don't use blocked literals), but fixing these issues for general clauses appear to have made ternary clause optimization irrelevant based on what was measured.
This commit is contained in:
Nikolaj Bjorner 2022-10-30 03:57:39 -07:00
parent 0da0fa2b27
commit 9fc4015c46
13 changed files with 16 additions and 386 deletions
Download patch file Download diff file Expand all files Collapse all files

28
src/sat/smt/pb_solver.cpp
View file

@ -690,15 +690,6 @@ namespace pb {
inc_coeff(consequent, offset);
process_antecedent(js.get_literal(), offset);
break;
#if ENABLE_TERNARY
case sat::justification::TERNARY:
inc_bound(offset);
SASSERT (consequent != sat::null_literal);
inc_coeff(consequent, offset);
process_antecedent(js.get_literal1(), offset);
process_antecedent(js.get_literal2(), offset);
break;
#endif
case sat::justification::CLAUSE: {
inc_bound(offset);
sat::clause & c = s().get_clause(js);
@ -1019,16 +1010,6 @@ namespace pb {
inc_coeff(consequent, 1);
process_antecedent(js.get_literal());
break;
#if ENABLE_TERNARY
case sat::justification::TERNARY:
SASSERT(consequent != sat::null_literal);
round_to_one(consequent.var());
inc_bound(1);
inc_coeff(consequent, 1);
process_antecedent(js.get_literal1());
process_antecedent(js.get_literal2());
break;
#endif
case sat::justification::CLAUSE: {
sat::clause & c = s().get_clause(js);
unsigned i = 0;
@ -3476,15 +3457,6 @@ namespace pb {
ineq.push(lit, offset);
ineq.push(js.get_literal(), offset);
break;
#if ENABLE_TERNARY
case sat::justification::TERNARY:
SASSERT(lit != sat::null_literal);
ineq.reset(offset);
ineq.push(lit, offset);
ineq.push(js.get_literal1(), offset);
ineq.push(js.get_literal2(), offset);
break;
#endif
case sat::justification::CLAUSE: {
ineq.reset(offset);
sat::clause & c = s().get_clause(js);