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add shortcuts for concatenation and equality propagation

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-12-08 16:17:04 +05:30
parent c8d9be0bbf
commit faebbc5384
3 changed files with 32 additions and 190 deletions
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48
src/smt/theory_seq.cpp
View file

@ -397,15 +397,13 @@ bool theory_seq::branch_binary_variable(eq const& e) {
expr_ref Y1(mk_skolem(symbol("seq.left"), x, y), m);
expr_ref Y2(mk_skolem(symbol("seq.right"), x, y), m);
ys.push_back(Y1);
expr_ref ysY1(m_util.str.mk_concat(ys.size(), ys.c_ptr()), m);
expr_ref xsE(m_util.str.mk_concat(xs.size(), xs.c_ptr()), m);
expr_ref Y1Y2(m_util.str.mk_concat(Y1, Y2), m);
literal_vector lits;
lits.push_back(~lit);
expr_ref ysY1(mk_concat(ys));
expr_ref xsE(mk_concat(xs));
expr_ref Y1Y2(mk_concat(Y1, Y2));
dependency* dep = e.dep();
propagate_eq(dep, lits, x, ysY1, true);
propagate_eq(dep, lits, y, Y1Y2, true);
propagate_eq(dep, lits, Y2, xsE, true);
propagate_eq(dep, ~lit, x, ysY1);
propagate_eq(dep, ~lit, y, Y1Y2);
propagate_eq(dep, ~lit, Y2, xsE);
}
else {
ctx.mark_as_relevant(lit);
@ -471,9 +469,7 @@ void theory_seq::branch_unit_variable(dependency* dep, expr* X, expr_ref_vector
literal lit = mk_eq(m_autil.mk_int(lX), m_util.str.mk_length(X), false);
if (l_true == ctx.get_assignment(lit)) {
expr_ref R(m_util.str.mk_concat(lX, units.c_ptr()), m);
literal_vector lits;
lits.push_back(lit);
propagate_eq(dep, lits, X, R, true);
propagate_eq(dep, lit, X, R);
TRACE("seq", tout << "propagate " << mk_pp(X, m) << " " << R << "\n";);
}
else {
@ -506,11 +502,10 @@ bool theory_seq::branch_variable_mb() {
for (unsigned j = 0; j < len2.size(); ++j) l2 += len2[j];
if (l1 != l2) {
TRACE("seq", tout << "lengths are not compatible\n";);
expr_ref l = mk_concat(e.ls().size(), e.ls().c_ptr());
expr_ref r = mk_concat(e.rs().size(), e.rs().c_ptr());
expr_ref l = mk_concat(e.ls());
expr_ref r = mk_concat(e.rs());
expr_ref lnl(m_util.str.mk_length(l), m), lnr(m_util.str.mk_length(r), m);
literal_vector lits;
propagate_eq(e.dep(), lits, lnl, lnr, false);
propagate_eq(e.dep(), lnl, lnr, false);
change = true;
continue;
}
@ -626,8 +621,8 @@ bool theory_seq::split_lengths(dependency* dep,
SASSERT(is_var(Y));
expr_ref Y1(mk_skolem(symbol("seq.left"), X, b, Y), m);
expr_ref Y2(mk_skolem(symbol("seq.right"), X, b, Y), m);
expr_ref bY1(m_util.str.mk_concat(b, Y1), m);
expr_ref Y1Y2(m_util.str.mk_concat(Y1, Y2), m);
expr_ref bY1 = mk_concat(b, Y1);
expr_ref Y1Y2 = mk_concat(Y1, Y2);
propagate_eq(dep, lits, X, bY1, true);
propagate_eq(dep, lits, Y, Y1Y2, true);
}
@ -1317,6 +1312,18 @@ void theory_seq::propagate_eq(dependency* dep, enode* n1, enode* n2) {
enforce_length_coherence(n1, n2);
}
void theory_seq::propagate_eq(dependency* dep, expr* e1, expr* e2, bool add_eq) {
literal_vector lits;
propagate_eq(dep, lits, e1, e2, add_eq);
}
void theory_seq::propagate_eq(dependency* dep, literal lit, expr* e1, expr* e2, bool add_to_eqs) {
literal_vector lits;
lits.push_back(lit);
propagate_eq(dep, lits, e1, e2, add_to_eqs);
}
void theory_seq::enforce_length_coherence(enode* n1, enode* n2) {
expr* o1 = n1->get_owner();
expr* o2 = n2->get_owner();
@ -1662,19 +1669,18 @@ bool theory_seq::reduce_length(unsigned i, unsigned j, bool front, expr_ref_vect
}
SASSERT(0 < l1 && l1 < ls.size());
SASSERT(0 < r1 && r1 < rs.size());
expr_ref l(m_util.str.mk_concat(l1, ls1), m);
expr_ref r(m_util.str.mk_concat(r1, rs1), m);
expr_ref l = mk_concat(l1, ls1);
expr_ref r = mk_concat(r1, rs1);
expr_ref lenl(m_util.str.mk_length(l), m);
expr_ref lenr(m_util.str.mk_length(r), m);
literal lit = mk_eq(lenl, lenr, false);
if (ctx.get_assignment(lit) == l_true) {
literal_vector lits;
expr_ref_vector lhs(m), rhs(m);
lhs.append(l2, ls2);
rhs.append(r2, rs2);
deps = mk_join(deps, lit);
m_eqs.push_back(eq(m_eq_id++, lhs, rhs, deps));
propagate_eq(deps, lits, l, r, true);
propagate_eq(deps, l, r, true);
TRACE("seq", tout << "propagate eq\nlhs: " << lhs << "\nrhs: " << rhs << "\n";);
return true;
}

6
src/smt/theory_seq.h
View file

@ -410,6 +410,8 @@ namespace smt {
expr_ref mk_empty(sort* s) { return expr_ref(m_util.str.mk_empty(s), m); }
expr_ref mk_concat(unsigned n, expr*const* es) { return expr_ref(m_util.str.mk_concat(n, es), m); }
expr_ref mk_concat(expr_ref_vector const& es, sort* s) { if (es.empty()) return mk_empty(s); return mk_concat(es.size(), es.c_ptr()); }
expr_ref mk_concat(expr_ref_vector const& es) { SASSERT(!es.empty()); return mk_concat(es.size(), es.c_ptr()); }
expr_ref mk_concat(ptr_vector<expr> const& es) { SASSERT(!es.empty()); return mk_concat(es.size(), es.c_ptr()); }
expr_ref mk_concat(expr* e1, expr* e2) { return expr_ref(m_util.str.mk_concat(e1, e2), m); }
expr_ref mk_concat(expr* e1, expr* e2, expr* e3) { return expr_ref(m_util.str.mk_concat(e1, e2, e3), m); }
bool solve_nqs(unsigned i);
@ -436,7 +438,9 @@ namespace smt {
void propagate_lit(dependency* dep, unsigned n, literal const* lits, literal lit);
void propagate_eq(dependency* dep, enode* n1, enode* n2);
void propagate_eq(literal lit, expr* e1, expr* e2, bool add_to_eqs);
void propagate_eq(dependency* dep, literal_vector const& lits, expr* e1, expr* e2, bool add_to_eqs);
void propagate_eq(dependency* dep, literal_vector const& lits, expr* e1, expr* e2, bool add_to_eqs = true);
void propagate_eq(dependency* dep, expr* e1, expr* e2, bool add_to_eqs = true);
void propagate_eq(dependency* dep, literal lit, expr* e1, expr* e2, bool add_to_eqs = true);
void set_conflict(dependency* dep, literal_vector const& lits = literal_vector());
u_map<unsigned> m_branch_start;