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cutset updates

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2020-01-09 21:37:25 -08:00
parent e4cc9e8404
commit 607a1b3f99
6 changed files with 208 additions and 119 deletions
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48
src/sat/sat_aig_cuts.h
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@ -7,9 +7,20 @@
Abstract:
extract AIG definitions from clauses
Extract AIG definitions from clauses.
Perform cut-set enumeration to identify equivalences.
AIG extraction is incremental.
It can be called repeatedly.
Initially, a main aig node is inserted
(from initial clauses or the input
clausification in goal2sat).
Then, auxiliary AIG nodes can be inserted
by walking the current set of main and learned
clauses. AIG nodes with fewer arguments are preferred.
Author:
Nikolaj Bjorner 2020-01-02
@ -48,43 +59,50 @@ namespace sat {
unsigned m_max_cutset_size;
unsigned m_max_aux;
unsigned m_max_insertions;
config(): m_max_cut_size(4), m_max_cutset_size(10), m_max_aux(3), m_max_insertions(10) {}
config(): m_max_cut_size(4), m_max_cutset_size(10), m_max_aux(5), m_max_insertions(10) {}
};
// encodes one of var, and, !and, xor, !xor, ite, !ite.
class node {
bool m_sign;
bool_op m_op;
unsigned m_num_children;
unsigned m_size;
unsigned m_offset;
public:
node(): m_sign(false), m_op(no_op), m_num_children(UINT_MAX), m_offset(UINT_MAX) {}
explicit node(unsigned v): m_sign(false), m_op(var_op), m_num_children(UINT_MAX), m_offset(v) {}
explicit node(bool negate, bool_op op, unsigned nc, unsigned o):
m_sign(negate), m_op(op), m_num_children(nc), m_offset(o) {}
node():
m_sign(false), m_op(no_op), m_size(UINT_MAX), m_offset(UINT_MAX) {}
explicit node(unsigned v) :
m_sign(false), m_op(var_op), m_size(0), m_offset(v) {}
explicit node(bool sign, bool_op op, unsigned nc, unsigned o) :
m_sign(sign), m_op(op), m_size(nc), m_offset(o) {}
bool is_valid() const { return m_offset != UINT_MAX; }
bool_op op() const { return m_op; }
bool is_var() const { return m_op == var_op; }
bool is_and() const { return m_op == and_op; }
bool is_xor() const { return m_op == xor_op; }
bool is_ite() const { return m_op == ite_op; }
bool is_const() const { return is_and() && num_children() == 0; }
bool is_const() const { return is_and() && size() == 0; }
unsigned var() const { SASSERT(is_var()); return m_offset; }
bool sign() const { return m_sign; }
unsigned num_children() const { SASSERT(!is_var()); return m_num_children; }
unsigned size() const { return m_size; }
unsigned offset() const { return m_offset; }
};
random_gen m_rand;
config m_config;
svector<node> m_aig; // vector of main aig nodes.
vector<svector<node>> m_aux_aig; // vector of auxiliary aig nodes.
vector<svector<node>> m_aig;
literal_vector m_literals;
region m_region;
cut_set m_cut_set1, m_cut_set2;
vector<cut_set> m_cuts;
bool_var m_true;
unsigned_vector m_last_touched;
unsigned m_num_cut_calls;
svector<std::pair<bool_var, literal>> m_roots;
unsigned m_insertions;
bool is_touched(node const& n);
bool is_touched(literal lit) const { return is_touched(lit.var()); }
bool is_touched(bool_var v) const { return m_last_touched[v] + m_aig.size() >= m_num_cut_calls * m_aig.size(); }
void touch(bool_var v) { m_last_touched[v] = v + m_num_cut_calls * m_aig.size(); }
void reserve(unsigned v);
bool insert_aux(unsigned v, node const& n);
void init_cut_set(unsigned id);
@ -93,7 +111,7 @@ namespace sat {
unsigned_vector filter_valid_nodes() const;
void augment(unsigned_vector const& ids);
void augment(node const& n, cut_set& cs);
void augment(unsigned id, node const& n);
void augment_ite(node const& n, cut_set& cs);
void augment_aig0(node const& n, cut_set& cs);
void augment_aig1(node const& n, cut_set& cs);
@ -108,7 +126,7 @@ namespace sat {
std::ostream& display(std::ostream& out, node const& n) const;
literal child(node const& n, unsigned idx) const { SASSERT(!n.is_var()); SASSERT(idx < n.num_children()); return m_literals[n.offset() + idx]; }
literal child(node const& n, unsigned idx) const { SASSERT(!n.is_var()); SASSERT(idx < n.size()); return m_literals[n.offset() + idx]; }
public:
aig_cuts();
@ -116,7 +134,7 @@ namespace sat {
void add_node(literal head, bool_op op, unsigned sz, literal const* args);
void set_root(bool_var v, literal r);
vector<cut_set> const & get_cuts();
vector<cut_set> const & operator()();
std::ostream& display(std::ostream& out) const;
};