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add rule unfolding transformation

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2012-10-15 15:34:29 -07:00
parent 2c24f25050
commit d16db63e56
13 changed files with 160 additions and 138 deletions
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2
lib/dl_bmc_engine.cpp
View file

@ -118,7 +118,7 @@ namespace datalog {
expr_ref level_query = mk_level_predicate(m_query_pred, level);
model_ref md;
proof_ref pr(m);
rule_unifier unifier(rm, m_ctx, m);
rule_unifier unifier(m_ctx);
m_solver.get_model(md);
func_decl* pred = m_query_pred;
SASSERT(m.is_true(md->get_const_interp(to_app(level_query)->get_decl())));

6
lib/dl_mk_rule_inliner.cpp
View file

@ -91,7 +91,7 @@ namespace datalog {
}
void rule_unifier::apply(
rule& r, bool is_tgt, unsigned skipped_index,
rule const& r, bool is_tgt, unsigned skipped_index,
app_ref_vector& res, svector<bool>& res_neg) {
unsigned rule_len = r.get_tail_size();
for (unsigned i = 0; i < rule_len; i++) {
@ -104,7 +104,7 @@ namespace datalog {
}
}
bool rule_unifier::apply(rule& tgt, unsigned tail_index, rule& src, rule_ref& res) {
bool rule_unifier::apply(rule const& tgt, unsigned tail_index, rule const& src, rule_ref& res) {
SASSERT(m_ready);
app_ref new_head(m);
app_ref_vector tail(m);
@ -116,7 +116,7 @@ namespace datalog {
mk_rule_inliner::remove_duplicate_tails(tail, tail_neg);
SASSERT(tail.size()==tail_neg.size());
res = m_rm.mk(new_head, tail.size(), tail.c_ptr(), tail_neg.c_ptr());
res->set_accounting_parent_object(m_context, &tgt);
res->set_accounting_parent_object(m_context, const_cast<rule*>(&tgt));
res->norm_vars(m_rm);
if (m_context.fix_unbound_vars()) {
m_rm.fix_unbound_vars(res, true);

15
lib/dl_mk_rule_inliner.h
View file

@ -40,24 +40,25 @@ namespace datalog {
bool m_ready;
unsigned m_deltas[2];
public:
rule_unifier(rule_manager& rm, context& ctx, ast_manager& m)
: m(m), m_rm(rm), m_context(ctx), m_interp_simplifier(ctx), m_subst(m), m_unif(m), m_ready(false) {}
rule_unifier(context& ctx)
: m(ctx.get_manager()), m_rm(ctx.get_rule_manager()), m_context(ctx),
m_interp_simplifier(ctx), m_subst(m), m_unif(m), m_ready(false) {}
/** Reset subtitution and unify tail tgt_idx of the target rule and the head of the src rule */
bool unify_rules(const rule& tgt, unsigned tgt_idx, const rule& src);
bool unify_rules(rule const& tgt, unsigned tgt_idx, rule const& src);
/**
\brief Apply unifier to rules.
Return false if the resulting rule is a tautology (the interpreted tail is unsat).
*/
bool apply(rule& tgt, unsigned tgt_idx, rule& src, rule_ref& result);
bool apply(rule const& tgt, unsigned tgt_idx, rule const& src, rule_ref& result);
void display(std::ostream& stm) { m_subst.display(stm, 2, m_deltas); }
/**
Retrieve substitutions for src/tgt. (second argument of unify_rules).
*/
expr_ref_vector get_rule_subst(const rule& r, bool is_tgt);
expr_ref_vector get_rule_subst(rule const& r, bool is_tgt);
private:
void apply(app * a, bool is_tgt, app_ref& res);
@ -66,7 +67,7 @@ namespace datalog {
Apply substitution to a rule tail. Tail with skipped_index is skipped,
unless skipped_index is equal to UINT_MAX
*/
void apply(rule& r, bool is_tgt, unsigned skipped_index, app_ref_vector& res,
void apply(rule const& r, bool is_tgt, unsigned skipped_index, app_ref_vector& res,
svector<bool>& res_neg);
};
@ -178,7 +179,7 @@ namespace datalog {
m_simp(m_context.get_rewriter()),
m_pinned(m_rm),
m_inlined_rules(m_context),
m_unifier(ctx.get_rule_manager(), ctx, m),
m_unifier(ctx),
m_mc(0),
m_pc(0),
m_head_index(m),

2
lib/dl_mk_slice.cpp
View file

@ -259,7 +259,7 @@ namespace datalog {
rm(ctx.get_rule_manager()),
m_pinned_rules(rm),
m_pinned_exprs(m),
m_unifier(rm, ctx, m) {}
m_unifier(ctx) {}
void insert(rule* orig_rule, rule* slice_rule, unsigned sz, unsigned const* renaming) {
m_rule2slice.insert(orig_rule, slice_rule);

72
lib/dl_mk_unfold.cpp Normal file
View file

@ -0,0 +1,72 @@
/*++
Copyright (c) 2012 Microsoft Corporation
Module Name:
dl_mk_unfold.cpp
Abstract:
Unfold rules once, return the unfolded set of rules.
Author:
Nikolaj Bjorner (nbjorner) 2012-10-15
Revision History:
--*/
#include "dl_mk_unfold.h"
namespace datalog {
mk_unfold::mk_unfold(context& ctx):
rule_transformer::plugin(0, false),
m_ctx(ctx),
m(ctx.get_manager()),
rm(ctx.get_rule_manager()),
m_unify(ctx)
{}
void mk_unfold::expand_tail(rule& r, unsigned tail_idx, rule_set const& src, rule_set& dst) {
SASSERT(tail_idx <= r.get_uninterpreted_tail_size());
if (tail_idx == r.get_uninterpreted_tail_size()) {
dst.add_rule(&r);
}
else {
func_decl* p = r.get_decl(tail_idx);
rule_vector const& p_rules = src.get_predicate_rules(p);
rule_ref new_rule(rm);
for (unsigned i = 0; i < p_rules.size(); ++i) {
rule const& r2 = *p_rules[i];
if (m_unify.unify_rules(r, tail_idx, r2) &&
m_unify.apply(r, tail_idx, r2, new_rule)) {
expr_ref_vector s1 = m_unify.get_rule_subst(r, true);
expr_ref_vector s2 = m_unify.get_rule_subst(r2, false);
resolve_rule(m_pc, r, r2, tail_idx, s1, s2, *new_rule.get());
expand_tail(*new_rule.get(), tail_idx+r2.get_uninterpreted_tail_size(), src, dst);
}
}
}
}
rule_set * mk_unfold::operator()(rule_set const & source, model_converter_ref& mc, proof_converter_ref& pc) {
m_pc = 0;
ref<replace_proof_converter> rpc;
if (pc) {
rpc = alloc(replace_proof_converter, m);
m_pc = rpc.get();
}
rule_set* rules = alloc(rule_set, m_ctx);
rule_set::iterator it = source.begin(), end = source.end();
for (; it != end; ++it) {
expand_tail(**it, 0, source, *rules);
}
if (pc) {
pc = concat(pc.get(), rpc.get());
}
return rules;
}
};

54
lib/dl_mk_unfold.h Normal file
View file

@ -0,0 +1,54 @@
/*++
Copyright (c) 2012 Microsoft Corporation
Module Name:
dl_mk_unfold.h
Abstract:
Unfold rules once, return the unfolded set of rules.
Author:
Nikolaj Bjorner (nbjorner) 2012-10-15
Revision History:
--*/
#ifndef _DL_MK_UNFOLD_H_
#define _DL_MK_UNFOLD_H_
#include"dl_context.h"
#include"dl_rule_set.h"
#include"uint_set.h"
#include"dl_rule_transformer.h"
#include"dl_mk_rule_inliner.h"
namespace datalog {
/**
\brief Implements an unfolding transformation.
*/
class mk_unfold : public rule_transformer::plugin {
context& m_ctx;
ast_manager& m;
rule_manager& rm;
rule_unifier m_unify;
replace_proof_converter* m_pc;
void expand_tail(rule& r, unsigned tail_idx, rule_set const& src, rule_set& dst);
public:
/**
\brief Create unfold rule transformer.
*/
mk_unfold(context & ctx);
rule_set * operator()(rule_set const & source, model_converter_ref& mc, proof_converter_ref& pc);
};
};
#endif /* _DL_MK_UNFOLD_H_ */

4
lib/dl_util.cpp
View file

@ -615,8 +615,8 @@ namespace datalog {
}
}
void resolve_rule(replace_proof_converter* pc, rule& r1, rule& r2, unsigned idx,
expr_ref_vector const& s1, expr_ref_vector const& s2, rule& res) {
void resolve_rule(replace_proof_converter* pc, rule const& r1, rule const& r2, unsigned idx,
expr_ref_vector const& s1, expr_ref_vector const& s2, rule const& res) {
if (!pc) return;
ast_manager& m = s1.get_manager();
dl_decl_util util(m);

4
lib/dl_util.h
View file

@ -467,8 +467,8 @@ namespace datalog {
void del_rule(horn_subsume_model_converter* mc, rule& r);
void resolve_rule(replace_proof_converter* pc, rule& r1, rule& r2, unsigned idx,
expr_ref_vector const& s1, expr_ref_vector const& s2, rule& res);
void resolve_rule(replace_proof_converter* pc, rule const& r1, rule const& r2, unsigned idx,
expr_ref_vector const& s1, expr_ref_vector const& s2, rule const& res);
model_converter* mk_skip_model_converter();

2
lib/lib.vcxproj
View file

@ -559,6 +559,7 @@
<ClCompile Include="dl_mk_simple_joins.cpp" />
<ClCompile Include="dl_mk_subsumption_checker.cpp" />
<ClCompile Include="dl_mk_unbound_compressor.cpp" />
<ClCompile Include="dl_mk_unfold.cpp" />
<ClCompile Include="dl_relation_manager.cpp" />
<ClCompile Include="dl_product_relation.cpp" />
<ClCompile Include="dl_rule.cpp" />
@ -1009,6 +1010,7 @@
<ClInclude Include="dl_mk_similarity_compressor.h" />
<ClInclude Include="dl_mk_subsumption_checker.h" />
<ClInclude Include="dl_mk_unbound_compressor.h" />
<ClInclude Include="dl_mk_unfold.h" />
<ClInclude Include="dl_relation_manager.h" />
<ClInclude Include="dl_product_relation.h" />
<ClInclude Include="dl_rule_subsumption_index.h" />

2
lib/pdr_context.cpp
View file

@ -1026,7 +1026,7 @@ namespace pdr {
ast_manager& m = pt.get_manager();
datalog::context& dctx = ctx.get_context();
datalog::rule_manager& rm = dctx.get_rule_manager();
datalog::rule_unifier unifier(rm, dctx, m);
datalog::rule_unifier unifier(dctx);
datalog::dl_decl_util util(m);
datalog::rule_ref r0(rm), r1(rm);
obj_map<expr, proof*> cache;

13
lib/pdr_dl_interface.cpp
View file

@ -30,6 +30,7 @@ Revision History:
#include "pdr_dl_interface.h"
#include "dl_rule_set.h"
#include "dl_mk_slice.h"
#include "dl_mk_unfold.h"
using namespace pdr;
@ -117,6 +118,17 @@ lbool dl_interface::query(expr * query) {
m_ctx.set_output_predicate(query_pred);
}
if (m_ctx.get_params().get_uint(":unfold-rules",0) > 0) {
unsigned num_unfolds = m_ctx.get_params().get_uint(":unfold-rules",0);
datalog::rule_transformer transformer(m_ctx);
datalog::mk_unfold* unfold = alloc(datalog::mk_unfold, m_ctx);
transformer.register_plugin(unfold);
while (num_unfolds > 0) {
m_ctx.transform_rules(transformer, mc, pc);
--num_unfolds;
}
}
IF_VERBOSE(2, m_ctx.display_rules(verbose_stream()););
m_pdr_rules.add_rules(m_ctx.get_rules());
m_pdr_rules.close();
@ -187,6 +199,7 @@ void dl_interface::collect_params(param_descrs& p) {
p.insert(":generate-proof-trace", CPK_BOOL, "PDR: (default false) trace for 'sat' answer as proof object");
p.insert(":inline-proofs", CPK_BOOL, "PDR: (default true) run PDR with proof mode turned on and extract Farkas coefficients directly (instead of creating a separate proof object when extracting coefficients)");
p.insert(":flexible-trace", CPK_BOOL, "PDR: (default false) allow PDR generate long counter-examples by extending candidate trace within search area");
p.insert(":unfold-rules", CPK_UINT, "PDR: (default 0) unfold rules statically using iterative squarring");
PRIVATE_PARAMS(p.insert(":use-farkas-model", CPK_BOOL, "PDR: (default false) enable using Farkas generalization through model propagation"););
PRIVATE_PARAMS(p.insert(":use-precondition-generalizer", CPK_BOOL, "PDR: (default false) enable generalizations from weakest pre-conditions"););
PRIVATE_PARAMS(p.insert(":use-multicore-generalizer", CPK_BOOL, "PDR: (default false) extract multiple cores for blocking states"););

120
lib/pdr_generalizers.cpp
View file

@ -683,123 +683,3 @@ namespace pdr {
}
};
#if 0
void model_farkas_generalizer::extract_eqs(expr_ref_vector const& lits, eqs& eqs) {
expr* e;
rational vl;
bool is_int;
for (unsigned i = 0; i < lits.size(); ++i) {
if (is_eq(lits[i], e, vl, is_int)) {
eqs.push_back(std::make_pair(e, vl));
}
}
}
void model_farkas_generalizer::solve_eqs(expr_ref& A, expr_ref_vector& other, eqs const& o_eqs) {
if (o_eqs.empty()) {
return;
}
expr_substitution sub(m);
scoped_ptr<expr_replacer> rep = mk_default_expr_replacer(m);
rep->set_substitution(&sub);
expr* e1;
rational vl1;
bool is_int;
for (unsigned i = 0; i < other.size(); ++i) {
if (is_eq(other[i].get(), e1, vl1, is_int)) {
unsigned k = m_random(o_eqs.size());
for (unsigned j = 0; j < o_eqs.size(); ++j) {
unsigned l = (j+k)%o_eqs.size();
expr* e2 = o_eqs[l].first;
if (m.get_sort(e1) == m.get_sort(e2)) {
sub.insert(e1, mk_offset(e2, vl1-o_eqs[l].second));
other[i] = m.mk_true();
break;
}
}
}
}
(*rep)(A);
other.push_back(A);
A = m.mk_and(other.size(), other.c_ptr());
}
expr* model_farkas_generalizer::mk_offset(expr* e, rational const& r) {
if (r.is_zero()) {
return e;
}
else {
return a.mk_add(e, a.mk_numeral(r, a.is_int(e)));
}
}
void model_farkas_generalizer::connect_vars(ptr_vector<expr>& vars, vector<rational>& vals, expr_ref_vector& lits) {
switch(vars.size()) {
case 0:
break;
case 1:
lits.push_back(m.mk_eq(vars[0], a.mk_numeral(vals[0], a.is_int(vars[0]))));
break;
case 2:
lits.push_back(m.mk_eq(vars[0], a.mk_numeral(vals[0], a.is_int(vars[0]))));
lits.push_back(m.mk_eq(vars[0], mk_offset(vars[1], vals[0]-vals[1])));
break;
default: {
ptr_vector<expr> new_vars;
vector<rational> new_vals;
unsigned j, i = m_random(vars.size());
new_vars.push_back(vars[i]);
new_vals.push_back(vals[i]);
lits.push_back(m.mk_eq(vars[i], a.mk_numeral(vals[i], a.is_int(vars[i]))));
vars.erase(vars.begin() + i);
vals.erase(vals.begin() + i);
while (!vars.empty()) {
i = m_random(vars.size());
j = m_random(new_vars.size());
lits.push_back(m.mk_eq(vars[i], mk_offset(new_vars[j], vals[i]-new_vals[j])));
new_vars.push_back(vars[i]);
new_vals.push_back(vals[i]);
vars.erase(vars.begin() + i);
vals.erase(vals.begin() + i);
}
break;
}
}
}
bool model_farkas_generalizer::is_eq(expr* e, expr*& r, rational& vl, bool& is_int) {
expr* r2 = 0;
return
(m.is_eq(e, r, r2) && a.is_numeral(r2, vl, is_int)) ||
(m.is_eq(e, r2, r) && a.is_numeral(r2, vl, is_int));
}
void model_farkas_generalizer::relativize(expr_ref_vector& literals) {
ast_manager& m = literals.get_manager();
ptr_vector<expr> ints, reals;
vector<rational> int_vals, real_vals;
expr* e;
rational vl;
bool is_int;
for (unsigned i = 0; i < literals.size(); ) {
if (is_eq(literals[i].get(), e, vl, is_int)) {
(is_int?ints:reals).push_back(e);
(is_int?int_vals:real_vals).push_back(vl);
literals[i] = literals.back();
literals.pop_back();
}
else {
++i;
}
}
connect_vars(ints, int_vals, literals);
connect_vars(reals, real_vals, literals);
}
#endif

2
lib/smt2scanner.cpp
View file

@ -110,7 +110,7 @@ namespace smt2 {
m_string.reset();
m_string.push_back(curr());
next();
read_symbol_core();
return read_symbol_core();
}
scanner::token scanner::read_number() {