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tune q-eval and q-ematch

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-09-28 13:41:37 -07:00
parent 92c1b600c3
commit da124e4275
7 changed files with 119 additions and 36 deletions
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15
src/ast/has_free_vars.cpp
View file

@ -18,9 +18,10 @@ Revision History:
--*/
#include "ast/ast.h"
#include "ast/expr_delta_pair.h"
#include "ast/has_free_vars.h"
#include "util/hashtable.h"
class contains_vars {
class contains_vars::imp {
typedef hashtable<expr_delta_pair, obj_hash<expr_delta_pair>, default_eq<expr_delta_pair> > cache;
cache m_cache;
svector<expr_delta_pair> m_todo;
@ -86,6 +87,18 @@ public:
}
};
contains_vars::contains_vars() {
m_imp = alloc(imp);
}
contains_vars::~contains_vars() {
dealloc(m_imp);
}
bool contains_vars::operator()(expr* e) {
return (*m_imp)(e);
}
bool has_free_vars(expr * n) {
contains_vars p;
return p(n);

9
src/ast/has_free_vars.h
View file

@ -20,6 +20,15 @@ Revision History:
class expr;
class contains_vars {
class imp;
imp* m_imp;
public:
contains_vars();
~contains_vars();
bool operator()(expr* n);
};
bool has_free_vars(expr * n);

14
src/ast/normal_forms/pull_quant.cpp
View file

@ -20,6 +20,7 @@ Notes:
#include "ast/rewriter/var_subst.h"
#include "ast/rewriter/rewriter_def.h"
#include "ast/ast_pp.h"
#include "ast/ast_util.h"
struct pull_quant::imp {
@ -50,7 +51,7 @@ struct pull_quant::imp {
quantifier * q = to_quantifier(child);
expr * body = q->get_expr();
quantifier_kind k = q->get_kind() == forall_k ? exists_k : forall_k;
result = m.update_quantifier(q, k, m.mk_not(body));
result = m.update_quantifier(q, k, mk_not(m, body));
return true;
}
else {
@ -78,9 +79,8 @@ struct pull_quant::imp {
qid = nested_q->get_qid();
}
w = std::min(w, nested_q->get_weight());
unsigned j = nested_q->get_num_decls();
while (j > 0) {
--j;
for (unsigned j = nested_q->get_num_decls(); j-- > 0; ) {
var_sorts.push_back(nested_q->get_decl_sort(j));
symbol s = nested_q->get_decl_name(j);
if (std::find(var_names.begin(), var_names.end(), s) != var_names.end())
@ -254,6 +254,10 @@ struct pull_quant::imp {
}
br_status reduce_app(func_decl * f, unsigned num, expr * const * args, expr_ref & result, proof_ref & result_pr) {
if (m.is_not(f) && m.is_not(args[0])) {
result = to_app(args[0])->get_arg(0);
return BR_REWRITE1;
}
if (!m.is_or(f) && !m.is_and(f) && !m.is_not(f))
return BR_FAILED;
@ -275,7 +279,7 @@ struct pull_quant::imp {
proof_ref & result_pr) {
if (is_exists(old_q)) {
result = m.mk_not(new_body);
result = mk_not(m, new_body);
result = m.mk_not(m.update_quantifier(old_q, forall_k, result));
if (m.proofs_enabled())
m.mk_rewrite(old_q, result);

2
src/sat/smt/q_eval.cpp
View file

@ -198,7 +198,7 @@ namespace q {
todo.pop_back();
continue;
}
if (is_ground(t) || (has_quantifiers(t) && !has_free_vars(t))) {
if (is_ground(t) || (has_quantifiers(t) && !m_contains_vars(t))) {
m_eval.setx(t->get_id(), ctx.get_egraph().find(t), nullptr);
if (!m_eval[t->get_id()])
return nullptr;

2
src/sat/smt/q_eval.h
View file

@ -16,6 +16,7 @@ Author:
--*/
#pragma once
#include "ast/has_free_vars.h"
#include "sat/smt/q_clause.h"
namespace euf {
@ -32,6 +33,7 @@ namespace q {
euf::enode_vector m_indirect_nodes;
bool m_freeze_swap = false;
euf::enode_pair m_diseq_undef;
contains_vars m_contains_vars;
struct scoped_mark_reset;

107
src/sat/smt/q_solver.cpp
View file

@ -30,7 +30,8 @@ namespace q {
th_euf_solver(ctx, ctx.get_manager().get_family_name(fid), fid),
m_mbqi(ctx, *this),
m_ematch(ctx, *this),
m_expanded(ctx.get_manager())
m_expanded(ctx.get_manager()),
m_der(ctx.get_manager())
{
}
@ -45,25 +46,22 @@ namespace q {
add_clause(~l, lit);
ctx.add_root(~l, lit);
}
else {
auto const& exp = expand(q);
if (exp.size() > 1) {
for (expr* e : exp) {
sat::literal lit = ctx.internalize(e, l.sign(), false, false);
add_clause(~l, lit);
ctx.add_root(~l, lit);
}
}
else if (is_ground(q->get_expr())) {
auto lit = ctx.internalize(q->get_expr(), l.sign(), false, false);
else if (expand(q)) {
for (expr* e : m_expanded) {
sat::literal lit = ctx.internalize(e, l.sign(), false, false);
add_clause(~l, lit);
ctx.add_root(~l, lit);
}
else {
ctx.push_vec(m_universal, l);
if (ctx.get_config().m_ematching)
m_ematch.add(q);
}
}
else if (is_ground(q->get_expr())) {
auto lit = ctx.internalize(q->get_expr(), l.sign(), false, false);
add_clause(~l, lit);
ctx.add_root(~l, lit);
}
else {
ctx.push_vec(m_universal, l);
if (ctx.get_config().m_ematching)
m_ematch.add(q);
}
m_stats.m_num_quantifier_asserts++;
}
@ -223,8 +221,16 @@ namespace q {
return val;
}
expr_ref_vector const& solver::expand(quantifier* q) {
bool solver::expand(quantifier* q) {
expr_ref r(m);
proof_ref pr(m);
m_der(q, r, pr);
m_expanded.reset();
if (r != q) {
ctx.get_rewriter()(r);
m_expanded.push_back(r);
return true;
}
if (is_forall(q))
flatten_and(q->get_expr(), m_expanded);
else if (is_exists(q))
@ -232,13 +238,31 @@ namespace q {
else
UNREACHABLE();
expr* a, *b;
if (m_expanded.size() == 1 && m.is_iff(m_expanded.get(0), a, b)) {
expr_ref f1(m.mk_implies(a, b), m);
expr_ref f2(m.mk_implies(b, a), m);
if (m_expanded.size() == 1 && is_forall(q)) {
m_expanded.reset();
m_expanded.push_back(f1);
m_expanded.push_back(f2);
flatten_or(q->get_expr(), m_expanded);
expr_ref split1(m), split2(m), e1(m), e2(m);
unsigned idx = 0;
for (unsigned i = m_expanded.size(); i-- > 0; ) {
expr* arg = m_expanded.get(i);
if (split(arg, split1, split2)) {
if (e1)
return false;
e1 = split1;
e2 = split2;
idx = i;
}
}
if (!e1)
return false;
m_expanded[idx] = e1;
e1 = mk_or(m_expanded);
m_expanded[idx] = e2;
e2 = mk_or(m_expanded);
m_expanded.reset();
m_expanded.push_back(e1);
m_expanded.push_back(e2);
}
if (m_expanded.size() > 1) {
for (unsigned i = m_expanded.size(); i-- > 0; ) {
@ -246,12 +270,39 @@ namespace q {
ctx.get_rewriter()(tmp);
m_expanded[i] = tmp;
}
return true;
}
else {
m_expanded.reset();
m_expanded.push_back(q);
return false;
}
bool solver::split(expr* arg, expr_ref& e1, expr_ref& e2) {
expr* x, * y, * z;
if (m.is_not(arg, x) && m.is_or(x, y, z) && is_literal(y) && is_literal(z)) {
e1 = mk_not(m, y);
e2 = mk_not(m, z);
return true;
}
return m_expanded;
if (m.is_iff(arg, x, y) && is_literal(x) && is_literal(y)) {
e1 = m.mk_implies(x, y);
e2 = m.mk_implies(y, x);
return true;
}
if (m.is_and(arg, x, y) && is_literal(x) && is_literal(y)) {
e1 = x;
e2 = y;
return true;
}
if (m.is_not(arg, z) && m.is_iff(z, x, y) && is_literal(x) && is_literal(y)) {
e1 = m.mk_or(x, y);
e2 = m.mk_or(mk_not(m, x), mk_not(m, y));
return true;
}
return false;
}
bool solver::is_literal(expr* arg) {
m.is_not(arg, arg);
return !m.is_and(arg) && !m.is_or(arg) && !m.is_iff(arg) && !m.is_implies(arg);
}
void solver::get_antecedents(sat::literal l, sat::ext_justification_idx idx, sat::literal_vector& r, bool probing) {

6
src/sat/smt/q_solver.h
View file

@ -18,6 +18,7 @@ Author:
#include "util/obj_hashtable.h"
#include "ast/ast_trail.h"
#include "ast/rewriter/der.h"
#include "sat/smt/sat_th.h"
#include "sat/smt/q_mbi.h"
#include "sat/smt/q_ematch.h"
@ -47,6 +48,7 @@ namespace q {
sat::literal_vector m_universal;
obj_map<sort, expr*> m_unit_table;
expr_ref_vector m_expanded;
der_rewriter m_der;
sat::literal instantiate(quantifier* q, bool negate, std::function<expr* (quantifier*, unsigned)>& mk_var);
sat::literal skolemize(quantifier* q);
@ -54,7 +56,9 @@ namespace q {
void init_units();
expr* get_unit(sort* s);
expr_ref_vector const& expand(quantifier* q);
bool expand(quantifier* q);
bool split(expr* arg, expr_ref& e1, expr_ref& e2);
bool is_literal(expr* arg);
friend class ematch;