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First partially working pdr strategy in spacer

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This commit is contained in:
Arie Gurfinkel 2018-06-05 16:12:45 -07:00
parent ab5f579d0b
commit 521392a8f1
5 changed files with 95 additions and 17 deletions
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1
src/muz/base/fixedpoint_params.pyg
View file

@ -203,4 +203,5 @@ def_module_params('fixedpoint',
('spacer.use_inc_clause', BOOL, False, 'Use incremental clause to represent trans'),
('spacer.dump_benchmarks', BOOL, False, 'Dump SMT queries as benchmarks'),
('spacer.dump_threshold', DOUBLE, 5.0, 'Threshold in seconds on dumping benchmarks'),
('spacer.gpdr', BOOL, False, 'Use GPDR solving strategy for non-linear CHC'),
))

13
src/muz/spacer/spacer_context.cpp
View file

@ -2591,7 +2591,14 @@ lbool context::solve(unsigned from_lvl)
{
m_last_result = l_undef;
try {
m_last_result = solve_core (from_lvl);
if (m_params.spacer_gpdr()) {
SASSERT(from_lvl == 0);
m_last_result = gpdr_solve_core();
}
else {
m_last_result = solve_core (from_lvl);
}
if (m_last_result == l_false) {
simplify_formulas();
m_last_result = l_false;
@ -2967,7 +2974,7 @@ lbool context::solve_core (unsigned from_lvl)
unsigned max_level = get_params ().spacer_max_level ();
for (unsigned i = 0; i < max_level; ++i) {
for (unsigned i = from_lvl; i < max_level; ++i) {
checkpoint();
m_expanded_lvl = infty_level ();
m_stats.m_max_query_lvl = lvl;
@ -3244,6 +3251,7 @@ void context::predecessor_eh()
/// out contains new pobs to add to the queue in case the result is l_undef
lbool context::expand_pob(pob& n, pob_ref_buffer &out)
{
SASSERT(out.empty());
pob::on_expand_event _evt(n);
TRACE ("spacer",
tout << "expand-pob: " << n.pt().head()->get_name()
@ -3630,7 +3638,6 @@ bool context::create_children(pob& n, datalog::rule const& r,
const vector<bool> &reach_pred_used,
pob_ref_buffer &out)
{
scoped_watch _w_ (m_create_children_watch);
pred_transformer& pt = n.pt();

6
src/muz/spacer/spacer_context.h
View file

@ -42,6 +42,8 @@ namespace datalog {
namespace spacer {
class model_search;
class pred_transformer;
class derivation;
class pob_queue;
@ -848,6 +850,10 @@ class context {
scoped_ptr_vector<spacer_callback> m_callbacks;
json_marshaller m_json_marshaller;
// Solve using gpdr strategy
lbool gpdr_solve_core();
bool gpdr_check_reachability(unsigned lvl, model_search &ms);
// Functions used by search.
lbool solve_core(unsigned from_lvl = 0);
bool is_requeue(pob &n);

86
src/muz/spacer/spacer_pdr.cpp
View file

@ -19,9 +19,10 @@ Notes:
--*/
#include "muz/spacer/spacer_pdr.h"
#include "muz/base/dl_context.h"
namespace spacer {
model_node::model_node(model_node* parent, pob_ref &pob):
model_node::model_node(model_node* parent, class pob *pob):
m_pob(pob), m_parent(parent), m_next(nullptr), m_prev(nullptr),
m_orig_level(m_pob->level()), m_depth(0),
m_closed(false) {
@ -30,7 +31,7 @@ model_node::model_node(model_node* parent, pob_ref &pob):
}
void model_node::add_child(model_node &kid) {
m_children.push_back(this);
m_children.push_back(&kid);
SASSERT(level() == kid.level() + 1);
SASSERT(level() > 0);
kid.m_depth = m_depth + 1;
@ -67,7 +68,7 @@ void model_node::set_open() {
}
void model_node::detach(model_node*& qhead) {
if (!in_queue()) return;
SASSERT(in_queue());
SASSERT(children().empty());
if (this == m_next) {
SASSERT(m_prev == this);
@ -103,13 +104,13 @@ void model_node::insert_after(model_node* n) {
}
void model_search::reset() {
m_cache.reset();
if (m_root) {
erase_children(*m_root, false);
remove_node(*m_root, false);
dealloc(m_root);
m_root = nullptr;
}
m_cache.reset();
}
model_node* model_search::pop_front() {
@ -135,6 +136,7 @@ void model_search::add_leaf(model_node& n) {
void model_search::enqueue_leaf(model_node& n) {
SASSERT(n.is_open());
SASSERT(!n.in_queue());
// queue is empty, initialize it with n
if (!m_qhead) {
m_qhead = &n;
@ -157,10 +159,7 @@ void model_search::set_root(model_node* root) {
m_root = root;
SASSERT(m_root);
SASSERT(m_root->children().empty());
SASSERT(cache(*root).empty());
// XXX Don't get why 1 is legal here
cache(*root).insert(root->post(), 1);
enqueue_leaf(*root);
add_leaf(*root);
}
void model_search::backtrack_level(bool uses_level, model_node& n) {
@ -189,8 +188,8 @@ void model_search::erase_children(model_node& n, bool backtrack) {
ptr_vector<model_node> todo, nodes;
todo.append(n.children());
// detach n from queue
n.detach(m_qhead);
n.reset();
if (n.in_queue()) n.detach(m_qhead);
n.reset_children();
while (!todo.empty()) {
model_node* m = todo.back();
todo.pop_back();
@ -205,7 +204,7 @@ void model_search::erase_children(model_node& n, bool backtrack) {
void model_search::remove_node(model_node& n, bool backtrack) {
model_nodes& nodes = cache(n).find(n.post());
nodes.erase(&n);
n.detach(m_qhead);
if (n.in_queue()) n.detach(m_qhead);
// TBD: siblings would also fail if n is not a goal.
if (!nodes.empty() && backtrack &&
nodes[0]->children().empty() && nodes[0]->is_closed()) {
@ -218,4 +217,69 @@ void model_search::remove_node(model_node& n, bool backtrack) {
}
lbool context::gpdr_solve_core() {
scoped_watch _w_(m_solve_watch);
//if there is no query predicate, abort
if (!m_rels.find(m_query_pred, m_query)) { return l_false; }
model_search ms(true);
unsigned lvl = 0;
unsigned max_level = get_params ().spacer_max_level ();
for (lvl = 0; lvl < max_level; ++lvl) {
checkpoint();
IF_VERBOSE(1,verbose_stream() << "GPDR Entering level "<< lvl << "\n";);
STRACE("spacer.expand-add", tout << "\n* LEVEL " << lvl << "\n";);
m_expanded_lvl = infty_level();
m_stats.m_max_query_lvl = lvl;
if (gpdr_check_reachability(lvl, ms)) {return l_true;}
if (lvl > 0) {
if (propagate(m_expanded_lvl, lvl, UINT_MAX)) {return l_false;}
}
}
// communicate failure to datalog::context
if (m_context) { m_context->set_status(datalog::BOUNDED); }
return l_undef;
}
bool context::gpdr_check_reachability(unsigned lvl, model_search &ms) {
pob_ref root_pob = m_query->mk_pob(nullptr, lvl, 0, m.mk_true());
model_node *root_node = alloc(model_node, nullptr, root_pob.get());
ms.set_root(root_node);
pob_ref_buffer new_pobs;
while (model_node *node = ms.pop_front()) {
IF_VERBOSE(2, verbose_stream() << "Expand node: "
<< node->level() << "\n";);
new_pobs.reset();
checkpoint();
switch (expand_pob(*node->pob(), new_pobs)){
case l_true:
node->set_closed();
if (node == root_node) return true;
break;
case l_false:
ms.backtrack_level(false, *node);
if (node == root_node) return false;
break;
case l_undef:
SASSERT(!new_pobs.empty());
for (auto pob : new_pobs) {
TRACE("spacer_pdr",
tout << "looking at pob at level " << pob->level() << " "
<< mk_pp(pob->post(), m) << "\n";);
if (pob == node->pob()) {continue;}
model_node *kid = alloc(model_node, node, pob);
ms.add_leaf(*kid);
}
node->check_pre_closed();
break;
}
}
return root_node->is_closed();
}
} // spacer

6
src/muz/spacer/spacer_pdr.h
View file

@ -35,7 +35,7 @@ class model_node {
unsigned m_depth; //
bool m_closed; // whether the pob is derivable
public:
model_node(model_node* parent, pob_ref &pob);
model_node(model_node* parent, pob* pob);
void add_child(model_node &kid);
expr *post() const {return m_pob->post();}
@ -43,7 +43,7 @@ public:
unsigned orig_level() const { return m_orig_level; }
unsigned depth() const { return m_depth; }
void increase_level() { m_pob->inc_level(); }
const pob_ref &pob() const { return m_pob; }
pob_ref &pob() { return m_pob; }
ptr_vector<model_node> const& children() { return m_children; }
pred_transformer& pt() const { return m_pob->pt(); }
model_node* parent() const { return m_parent; }
@ -66,7 +66,7 @@ public:
void set_closed() {m_closed = true;}
void set_open();
void reset() {m_children.reset();}
void reset_children() {m_children.reset();}
/// queue