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Add option to control explosion of cofactor-term-ite following example by Anvesh

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-06-18 09:52:59 -07:00
parent aba79802cf
commit 1ed7643d32
3 changed files with 34 additions and 25 deletions
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54
src/tactic/core/cofactor_elim_term_ite.cpp
View file

@ -29,14 +29,15 @@ struct cofactor_elim_term_ite::imp {
ast_manager & m;
params_ref m_params;
unsigned long long m_max_memory;
volatile bool m_cancel;
bool m_cofactor_equalities;
volatile bool m_cancel;
void checkpoint() {
cooperate("cofactor ite");
if (memory::get_allocation_size() > m_max_memory)
throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
if (m_cancel)
throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
throw tactic_exception(TACTIC_CANCELED_MSG);
}
// Collect atoms that contain term if-then-else
@ -111,7 +112,7 @@ struct cofactor_elim_term_ite::imp {
frame & fr = m_frame_stack.back();
expr * t = fr.m_t;
bool form_ctx = fr.m_form_ctx;
TRACE("cofactor_ite_analyzer", tout << "processing, form_ctx: " << form_ctx << "\n" << mk_bounded_pp(t, m) << "\n";);
TRACE("cofactor", tout << "processing, form_ctx: " << form_ctx << "\n" << mk_bounded_pp(t, m) << "\n";);
m_owner.checkpoint();
@ -150,7 +151,7 @@ struct cofactor_elim_term_ite::imp {
}
if (i < num_args) {
m_has_term_ite.mark(t);
TRACE("cofactor_ite_analyzer", tout << "saving candidate: " << form_ctx << "\n" << mk_bounded_pp(t, m) << "\n";);
TRACE("cofactor", tout << "saving candidate: " << form_ctx << "\n" << mk_bounded_pp(t, m) << "\n";);
save_candidate(t, form_ctx);
}
}
@ -167,6 +168,7 @@ struct cofactor_elim_term_ite::imp {
};
expr * get_first(expr * t) {
TRACE("cofactor", tout << mk_ismt2_pp(t, m) << "\n";);
typedef std::pair<expr *, unsigned> frame;
expr_fast_mark1 visited;
sbuffer<frame> stack;
@ -225,6 +227,7 @@ struct cofactor_elim_term_ite::imp {
\brief Fuctor for selecting the term if-then-else condition with the most number of occurrences.
*/
expr * get_best(expr * t) {
TRACE("cofactor", tout << mk_ismt2_pp(t, m) << "\n";);
typedef std::pair<expr *, unsigned> frame;
obj_map<expr, unsigned> occs;
expr_fast_mark1 visited;
@ -299,12 +302,17 @@ struct cofactor_elim_term_ite::imp {
}
}
visited.reset();
CTRACE("cofactor_ite_get_best", best != 0, tout << "best num-occs: " << best_occs << "\n" << mk_ismt2_pp(best, m) << "\n";);
CTRACE("cofactor", best != 0, tout << "best num-occs: " << best_occs << "\n" << mk_ismt2_pp(best, m) << "\n";);
return best;
}
void updt_params(params_ref const & p) {
m_max_memory = megabytes_to_bytes(p.get_uint("max_memory", UINT_MAX));
m_cofactor_equalities = p.get_bool("cofactor_equalities", true);
}
void collect_param_descrs(param_descrs & r) {
r.insert("cofactor_equalities", CPK_BOOL, "(default: true) use equalities to rewrite bodies of ite-expressions. This is potentially expensive.");
}
void set_cancel(bool f) {
@ -354,16 +362,16 @@ struct cofactor_elim_term_ite::imp {
m_term = 0;
expr * lhs;
expr * rhs;
if (m.is_eq(t, lhs, rhs)) {
if (m_owner.m_cofactor_equalities && m.is_eq(t, lhs, rhs)) {
if (m.is_unique_value(lhs)) {
m_term = rhs;
m_value = to_app(lhs);
TRACE("set_cofactor_atom", tout << "term:\n" << mk_ismt2_pp(m_term, m) << "\nvalue: " << mk_ismt2_pp(m_value, m) << "\n";);
TRACE("cofactor", tout << "term:\n" << mk_ismt2_pp(m_term, m) << "\nvalue: " << mk_ismt2_pp(m_value, m) << "\n";);
}
else if (m.is_unique_value(rhs)) {
m_term = lhs;
m_value = to_app(rhs);
TRACE("set_cofactor_atom", tout << "term:\n" << mk_ismt2_pp(m_term, m) << "\nvalue: " << mk_ismt2_pp(m_value, m) << "\n";);
TRACE("cofactor", tout << "term:\n" << mk_ismt2_pp(m_term, m) << "\nvalue: " << mk_ismt2_pp(m_value, m) << "\n";);
}
}
// TODO: bounds
@ -467,7 +475,7 @@ struct cofactor_elim_term_ite::imp {
m_cofactor.set_cofactor_atom(neg_c);
m_cofactor(curr, neg_cofactor);
curr = m.mk_ite(c, pos_cofactor, neg_cofactor);
TRACE("cofactor_ite", tout << "cofactor_ite step: " << step << "\n" << mk_ismt2_pp(curr, m) << "\n";);
TRACE("cofactor", tout << "cofactor_ite step: " << step << "\n" << mk_ismt2_pp(curr, m) << "\n";);
}
}
return false;
@ -522,7 +530,7 @@ struct cofactor_elim_term_ite::imp {
void cofactor(expr * t, expr_ref & r) {
unsigned step = 0;
TRACE("cofactor_ite", tout << "cofactor target:\n" << mk_ismt2_pp(t, m) << "\n";);
TRACE("cofactor", tout << "cofactor target:\n" << mk_ismt2_pp(t, m) << "\n";);
expr_ref curr(m);
curr = t;
while (true) {
@ -543,21 +551,20 @@ struct cofactor_elim_term_ite::imp {
m_cofactor(curr, neg_cofactor);
if (pos_cofactor == neg_cofactor) {
curr = pos_cofactor;
TRACE("cofactor_ite", tout << "cofactor_ite step: " << step << "\n" << mk_ismt2_pp(curr, m) << "\n";);
continue;
}
if (m.is_true(pos_cofactor) && m.is_false(neg_cofactor)) {
else if (m.is_true(pos_cofactor) && m.is_false(neg_cofactor)) {
curr = c;
TRACE("cofactor_ite", tout << "cofactor_ite step: " << step << "\n" << mk_ismt2_pp(curr, m) << "\n";);
continue;
}
if (m.is_false(pos_cofactor) && m.is_true(neg_cofactor)) {
else if (m.is_false(pos_cofactor) && m.is_true(neg_cofactor)) {
curr = neg_c;
TRACE("cofactor_ite", tout << "cofactor_ite step: " << step << "\n" << mk_ismt2_pp(curr, m) << "\n";);
continue;
}
curr = m.mk_ite(c, pos_cofactor, neg_cofactor);
TRACE("cofactor_ite", tout << "cofactor_ite step: " << step << "\n" << mk_ismt2_pp(curr, m) << "\n";);
else {
curr = m.mk_ite(c, pos_cofactor, neg_cofactor);
}
TRACE("cofactor",
tout << "cofactor_ite step: " << step << "\n";
tout << "co-factor: " << mk_ismt2_pp(c, m) << "\n";
tout << mk_ismt2_pp(curr, m) << "\n";);
}
}
@ -570,6 +577,7 @@ struct cofactor_elim_term_ite::imp {
void operator()(expr * t, expr_ref & r) {
ptr_vector<expr> new_args;
SASSERT(m_frames.empty());
m_frames.push_back(frame(t, true));
while (!m_frames.empty()) {
m_owner.checkpoint();
@ -649,7 +657,8 @@ struct cofactor_elim_term_ite::imp {
imp(ast_manager & _m, params_ref const & p):
m(_m),
m_params(p) {
m_params(p),
m_cofactor_equalities(true) {
m_cancel = false;
updt_params(p);
}
@ -686,7 +695,8 @@ void cofactor_elim_term_ite::updt_params(params_ref const & p) {
m_imp->updt_params(p);
}
void cofactor_elim_term_ite::get_param_descrs(param_descrs & r) {
void cofactor_elim_term_ite::collect_param_descrs(param_descrs & r) {
m_imp->collect_param_descrs(r);
}
void cofactor_elim_term_ite::operator()(expr * t, expr_ref & r) {

2
src/tactic/core/cofactor_elim_term_ite.h
View file

@ -31,7 +31,7 @@ public:
virtual ~cofactor_elim_term_ite();
void updt_params(params_ref const & p);
static void get_param_descrs(param_descrs & r);
void collect_param_descrs(param_descrs & r);
void operator()(expr * t, expr_ref & r);

3
src/tactic/core/cofactor_term_ite_tactic.cpp
View file

@ -52,8 +52,7 @@ public:
virtual ~cofactor_term_ite_tactic() {}
virtual void updt_params(params_ref const & p) { m_params = p; m_elim_ite.updt_params(p); }
static void get_param_descrs(param_descrs & r) { cofactor_elim_term_ite::get_param_descrs(r); }
virtual void collect_param_descrs(param_descrs & r) { get_param_descrs(r); }
virtual void collect_param_descrs(param_descrs & r) { m_elim_ite.collect_param_descrs(r); }
virtual void operator()(goal_ref const & g,
goal_ref_buffer & result,