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reduce_args_tactic: make it aware that 'a + const' may be a unique value in bv theory

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it allows us to remove UFs that are of the form f(a + 1), f(a + 2), etc..
This commit is contained in:
Nuno Lopes 2016-03-10 10:15:09 +00:00
parent 0b1b5a4328
commit d6c3260db7
1 changed files with 65 additions and 94 deletions
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159
src/tactic/core/reduce_args_tactic.cpp
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@ -83,14 +83,34 @@ tactic * mk_reduce_args_tactic(ast_manager & m, params_ref const & p) {
struct reduce_args_tactic::imp {
ast_manager & m_manager;
bool m_produce_models;
bv_util m_bv;
ast_manager & m() const { return m_manager; }
imp(ast_manager & m):
m_manager(m) {
m_manager(m),
m_bv(m) {
}
static bool is_var_plus_offset(ast_manager& m, bv_util& bv, expr* e, expr*& base) {
expr *lhs, *rhs;
if (bv.is_bv_add(e, lhs, rhs) && bv.is_numeral(lhs)) {
base = rhs;
} else {
base = e;
}
return true;
}
static bool may_be_unique(ast_manager& m, bv_util& bv, expr* e, expr*& base) {
base = 0;
return m.is_unique_value(e) || is_var_plus_offset(m, bv, e, base);
}
static bool may_be_unique(ast_manager& m, bv_util& bv, expr* e) {
expr* base;
return may_be_unique(m, bv, e, base);
}
void checkpoint() {
if (m_manager.canceled())
@ -100,10 +120,12 @@ struct reduce_args_tactic::imp {
struct find_non_candidates_proc {
ast_manager & m_manager;
bv_util & m_bv;
obj_hashtable<func_decl> & m_non_cadidates;
find_non_candidates_proc(ast_manager & m, obj_hashtable<func_decl> & non_cadidates):
find_non_candidates_proc(ast_manager & m, bv_util & bv, obj_hashtable<func_decl> & non_cadidates):
m_manager(m),
m_bv(bv),
m_non_cadidates(non_cadidates) {
}
@ -122,7 +144,7 @@ struct reduce_args_tactic::imp {
unsigned j = n->get_num_args();
while (j > 0) {
--j;
if (m_manager.is_unique_value(n->get_arg(j)))
if (may_be_unique(m_manager, m_bv, n->get_arg(j)))
return;
}
m_non_cadidates.insert(d);
@ -135,7 +157,7 @@ struct reduce_args_tactic::imp {
*/
void find_non_candidates(goal const & g, obj_hashtable<func_decl> & non_candidates) {
non_candidates.reset();
find_non_candidates_proc proc(m_manager, non_candidates);
find_non_candidates_proc proc(m_manager, m_bv, non_candidates);
expr_fast_mark1 visited;
unsigned sz = g.size();
for (unsigned i = 0; i < sz; i++) {
@ -154,11 +176,13 @@ struct reduce_args_tactic::imp {
struct populate_decl2args_proc {
ast_manager & m_manager;
bv_util & m_bv;
obj_hashtable<func_decl> & m_non_cadidates;
obj_map<func_decl, bit_vector> & m_decl2args;
populate_decl2args_proc(ast_manager & m, obj_hashtable<func_decl> & nc, obj_map<func_decl, bit_vector> & d):
m_manager(m), m_non_cadidates(nc), m_decl2args(d) {}
obj_map<func_decl, svector<expr*> > m_decl2base; // for args = base + offset
populate_decl2args_proc(ast_manager & m, bv_util & bv, obj_hashtable<func_decl> & nc, obj_map<func_decl, bit_vector> & d):
m_manager(m), m_bv(bv), m_non_cadidates(nc), m_decl2args(d) {}
void operator()(var * n) {}
void operator()(quantifier * n) {}
@ -172,20 +196,25 @@ struct reduce_args_tactic::imp {
return; // declaration is not a candidate
unsigned j = n->get_num_args();
obj_map<func_decl, bit_vector>::iterator it = m_decl2args.find_iterator(d);
expr* base;
if (it == m_decl2args.end()) {
m_decl2args.insert(d, bit_vector());
svector<expr*>& bases = m_decl2base.insert_if_not_there2(d, svector<expr*>())->get_data().m_value;
bases.resize(j);
it = m_decl2args.find_iterator(d);
SASSERT(it != m_decl2args.end());
it->m_value.reserve(j);
while (j > 0) {
--j;
it->m_value.set(j, m_manager.is_unique_value(n->get_arg(j)));
it->m_value.set(j, may_be_unique(m_manager, m_bv, n->get_arg(j), base));
bases[j] = base;
}
} else {
svector<expr*>& bases = m_decl2base[d];
SASSERT(j == it->m_value.size());
while (j > 0) {
--j;
it->m_value.set(j, it->m_value.get(j) && m_manager.is_unique_value(n->get_arg(j)));
it->m_value.set(j, it->m_value.get(j) && may_be_unique(m_manager, m_bv, n->get_arg(j), base) && bases[j] == base);
}
}
}
@ -196,7 +225,7 @@ struct reduce_args_tactic::imp {
obj_map<func_decl, bit_vector> & decl2args) {
expr_fast_mark1 visited;
decl2args.reset();
populate_decl2args_proc proc(m_manager, non_candidates, decl2args);
populate_decl2args_proc proc(m_manager, m_bv, non_candidates, decl2args);
unsigned sz = g.size();
for (unsigned i = 0; i < sz; i++) {
checkpoint();
@ -291,67 +320,6 @@ struct reduce_args_tactic::imp {
}
}
};
struct populate_decl2arg_set_proc {
ast_manager & m_manager;
obj_map<func_decl, bit_vector> & m_decl2args;
decl2arg2func_map & m_decl2arg2funcs;
populate_decl2arg_set_proc(ast_manager & m,
obj_map<func_decl, bit_vector> & d,
decl2arg2func_map & ds):
m_manager(m), m_decl2args(d), m_decl2arg2funcs(ds) {}
void operator()(var * n) {}
void operator()(quantifier * n) {}
void operator()(app * n) {
if (n->get_num_args() == 0)
return; // ignore constants
func_decl * d = n->get_decl();
if (d->get_family_id() != null_family_id)
return; // ignore interpreted symbols
obj_map<func_decl, bit_vector>::iterator it = m_decl2args.find_iterator(d);
if (it == m_decl2args.end())
return; // not reducing the arguments of this declaration
bit_vector & bv = it->m_value;
arg2func * map = 0;
decl2arg2func_map::iterator it2 = m_decl2arg2funcs.find_iterator(d);
if (it2 == m_decl2arg2funcs.end()) {
map = alloc(arg2func, arg2func_hash_proc(bv), arg2func_eq_proc(bv));
m_decl2arg2funcs.insert(d, map);
}
else {
map = it2->m_value;
}
if (!map->contains(n)) {
// create fresh symbol...
ptr_buffer<sort> domain;
unsigned arity = d->get_arity();
for (unsigned i = 0; i < arity; i++) {
if (!bv.get(i))
domain.push_back(d->get_domain(i));
}
func_decl * new_d = m_manager.mk_fresh_func_decl(d->get_name(), symbol::null, domain.size(), domain.c_ptr(), d->get_range());
map->insert(n, new_d);
m_manager.inc_ref(n);
m_manager.inc_ref(new_d);
}
}
};
void populate_decl2arg_set(goal const & g,
obj_map<func_decl, bit_vector> & decl2args,
decl2arg2func_map & decl2arg2funcs) {
expr_fast_mark1 visited;
populate_decl2arg_set_proc proc(m_manager, decl2args, decl2arg2funcs);
unsigned sz = g.size();
for (unsigned i = 0; i < sz; i++) {
checkpoint();
quick_for_each_expr(proc, visited, g.form(i));
}
}
struct reduce_args_rw_cfg : public default_rewriter_cfg {
ast_manager & m;
@ -377,24 +345,31 @@ struct reduce_args_tactic::imp {
return BR_FAILED; // ignore constants
if (f->get_family_id() != null_family_id)
return BR_FAILED; // ignore interpreted symbols
decl2arg2func_map::iterator it = m_decl2arg2funcs.find_iterator(f);
if (it == m_decl2arg2funcs.end())
obj_map<func_decl, bit_vector>::iterator it = m_decl2args.find_iterator(f);
if (it == m_decl2args.end())
return BR_FAILED;
SASSERT(m_decl2args.contains(f));
bit_vector & bv = m_decl2args.find(f);
arg2func * map = it->m_value;
app_ref tmp(m);
tmp = m.mk_app(f, num, args);
CTRACE("reduce_args", !map->contains(tmp),
tout << "map does not contain tmp f: " << f->get_name() << "\n";
tout << mk_ismt2_pp(tmp, m) << "\n";
arg2func::iterator it = map->begin();
arg2func::iterator end = map->end();
for (; it != end; ++it) {
tout << mk_ismt2_pp(it->m_key, m) << "\n---> " << it->m_value->get_name() << "\n";
});
SASSERT(map->contains(tmp));
func_decl * new_f = map->find(tmp);
bit_vector & bv = it->m_value;
arg2func *& map = m_decl2arg2funcs.insert_if_not_there2(f, 0)->get_data().m_value;
if (!map) {
map = alloc(arg2func, arg2func_hash_proc(bv), arg2func_eq_proc(bv));
}
app_ref tmp(m.mk_app(f, num, args), m);
func_decl *& new_f = map->insert_if_not_there2(tmp, 0)->get_data().m_value;
if (!new_f) {
// create fresh symbol
ptr_buffer<sort> domain;
unsigned arity = f->get_arity();
for (unsigned i = 0; i < arity; ++i) {
if (!bv.get(i))
domain.push_back(f->get_domain(i));
}
new_f = m.mk_fresh_func_decl(f->get_name(), symbol::null, domain.size(), domain.c_ptr(), f->get_range());
m.inc_ref(tmp);
m.inc_ref(new_f);
}
ptr_buffer<expr> new_args;
for (unsigned i = 0; i < num; i++) {
if (!bv.get(i))
@ -470,7 +445,6 @@ struct reduce_args_tactic::imp {
void operator()(goal & g, model_converter_ref & mc) {
if (g.inconsistent())
return;
m_produce_models = g.models_enabled();
TRACE("reduce_args", g.display(tout););
tactic_report report("reduce-args", g);
obj_hashtable<func_decl> non_candidates;
@ -481,10 +455,7 @@ struct reduce_args_tactic::imp {
if (decl2args.empty())
return;
ptr_vector<arg2func> arg2funcs;
reduce_args_ctx ctx(m_manager);
populate_decl2arg_set(g, decl2args, ctx.m_decl2arg2funcs);
reduce_args_rw rw(*this, decl2args, ctx.m_decl2arg2funcs);
unsigned sz = g.size();
@ -499,7 +470,7 @@ struct reduce_args_tactic::imp {
report_tactic_progress(":reduced-funcs", decl2args.size());
if (m_produce_models)
if (g.models_enabled())
mc = mk_mc(decl2args, ctx.m_decl2arg2funcs);
TRACE("reduce_args", g.display(tout); if (mc) mc->display(tout););