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z3/lib/qflia_tactic.cpp
Leonardo de Moura e9eab22e5c Z3 sources
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2012-10-02 11:35:25 -07:00

219 lines
8.3 KiB
C++

/*++
Copyright (c) 2012 Microsoft Corporation
Module Name:
qflia_tactic.cpp
Abstract:
Tactic for QF_LIA
Author:
Leonardo (leonardo) 2012-02-26
Notes:
--*/
#include"tactical.h"
#include"simplify_tactic.h"
#include"propagate_values_tactic.h"
#include"propagate_ineqs_tactic.h"
#include"normalize_bounds_tactic.h"
#include"solve_eqs_tactic.h"
#include"elim_uncnstr_tactic.h"
#include"smt_tactic.h"
#include"mip_tactic.h"
#include"add_bounds_tactic.h"
#include"pb2bv_tactic.h"
#include"lia2pb_tactic.h"
#include"ctx_simplify_tactic.h"
#include"bit_blaster_tactic.h"
#include"max_bv_sharing_tactic.h"
#include"aig_tactic.h"
#include"sat_tactic.h"
#include"bound_manager.h"
#include"probe_arith.h"
struct quasi_pb_probe : public probe {
virtual result operator()(goal const & g) {
bool found_non_01 = false;
bound_manager bm(g.m());
bm(g);
rational l, u; bool st;
bound_manager::iterator it = bm.begin();
bound_manager::iterator end = bm.end();
for (; it != end; ++it) {
expr * t = *it;
if (bm.has_lower(t, l, st) && bm.has_upper(t, u, st) && (l.is_zero() || l.is_one()) && (u.is_zero() || u.is_one()))
continue;
if (found_non_01)
return false;
found_non_01 = true;
}
return true;
}
};
probe * mk_quasi_pb_probe() {
return mk_and(mk_not(mk_is_unbounded_probe()),
alloc(quasi_pb_probe));
}
// Create SMT solver that does not use cuts
static tactic * mk_no_cut_smt_tactic(unsigned rs) {
params_ref solver_p;
solver_p.set_uint(":arith-branch-cut-ratio", 10000000);
solver_p.set_uint(":random-seed", rs);
return using_params(mk_smt_tactic_using(false), solver_p);
}
// Create SMT solver that does not use cuts
static tactic * mk_no_cut_no_relevancy_smt_tactic(unsigned rs) {
params_ref solver_p;
solver_p.set_uint(":arith-branch-cut-ratio", 10000000);
solver_p.set_uint(":random-seed", rs);
solver_p.set_uint(":relevancy", 0);
return using_params(mk_smt_tactic_using(false), solver_p);
}
static tactic * mk_bv2sat_tactic(ast_manager & m) {
params_ref solver_p;
// The cardinality constraint encoding generates a lot of shared if-then-else's that can be flattened.
// Several of them are simplified to and/or. If we flat them, we increase a lot the memory consumption.
solver_p.set_bool(":flat", false);
solver_p.set_bool(":som", false);
// dynamic psm seems to work well.
solver_p.set_sym(":gc-strategy", symbol("dyn-psm"));
return using_params(and_then(mk_simplify_tactic(m),
mk_propagate_values_tactic(m),
mk_solve_eqs_tactic(m),
mk_max_bv_sharing_tactic(m),
mk_bit_blaster_tactic(m),
mk_aig_tactic(),
mk_sat_tactic(m)),
solver_p);
}
#define SMALL_SIZE 80000
static tactic * mk_pb_tactic(ast_manager & m) {
params_ref pb2bv_p;
pb2bv_p.set_bool(":ite-extra", true);
pb2bv_p.set_uint(":pb2bv-all-clauses-limit", 8);
return and_then(fail_if_not(mk_is_pb_probe()),
fail_if(mk_produce_proofs_probe()),
fail_if(mk_produce_unsat_cores_probe()),
or_else(and_then(fail_if(mk_ge(mk_num_exprs_probe(), mk_const_probe(SMALL_SIZE))),
fail_if_not(mk_is_ilp_probe()),
try_for(mk_mip_tactic(m), 8000),
mk_fail_if_undecided_tactic()),
and_then(using_params(mk_pb2bv_tactic(m), pb2bv_p),
fail_if_not(mk_is_qfbv_probe()),
mk_bv2sat_tactic(m))));
}
static tactic * mk_lia2sat_tactic(ast_manager & m) {
params_ref pb2bv_p;
pb2bv_p.set_bool(":ite-extra", true);
pb2bv_p.set_uint(":pb2bv-all-clauses-limit", 8);
return and_then(fail_if(mk_is_unbounded_probe()),
fail_if(mk_produce_proofs_probe()),
fail_if(mk_produce_unsat_cores_probe()),
mk_propagate_ineqs_tactic(m),
mk_normalize_bounds_tactic(m),
mk_lia2pb_tactic(m),
using_params(mk_pb2bv_tactic(m), pb2bv_p),
fail_if_not(mk_is_qfbv_probe()),
mk_bv2sat_tactic(m));
}
// Try to find a model for an unbounded ILP problem.
// Fails if the problem is no ILP.
static tactic * mk_ilp_model_finder_tactic(ast_manager & m) {
params_ref add_bounds_p1;
add_bounds_p1.set_rat(":add-bound-lower", rational(-16));
add_bounds_p1.set_rat(":add-bound-upper", rational(15));
params_ref add_bounds_p2;
add_bounds_p2.set_rat(":add-bound-lower", rational(-32));
add_bounds_p2.set_rat(":add-bound-upper", rational(31));
return and_then(fail_if_not(mk_and(mk_is_ilp_probe(), mk_is_unbounded_probe())),
fail_if(mk_produce_proofs_probe()),
fail_if(mk_produce_unsat_cores_probe()),
mk_propagate_ineqs_tactic(m),
or_else(try_for(mk_mip_tactic(m), 5000),
try_for(mk_no_cut_smt_tactic(100), 2000),
and_then(using_params(mk_add_bounds_tactic(m), add_bounds_p1),
try_for(mk_lia2sat_tactic(m), 5000)),
try_for(mk_no_cut_smt_tactic(200), 5000),
and_then(using_params(mk_add_bounds_tactic(m), add_bounds_p2),
try_for(mk_lia2sat_tactic(m), 10000)),
mk_mip_tactic(m)),
mk_fail_if_undecided_tactic());
}
static tactic * mk_bounded_tactic(ast_manager & m) {
return and_then(fail_if(mk_is_unbounded_probe()),
or_else(try_for(mk_no_cut_smt_tactic(100), 5000),
try_for(mk_no_cut_no_relevancy_smt_tactic(200), 5000),
try_for(mk_no_cut_smt_tactic(300), 15000)
),
mk_fail_if_undecided_tactic());
}
tactic * mk_qflia_tactic(ast_manager & m, params_ref const & p) {
params_ref main_p;
main_p.set_bool(":elim-and", true);
main_p.set_bool(":som", true);
// main_p.set_bool(":push-ite-arith", true);
params_ref pull_ite_p;
pull_ite_p.set_bool(":pull-cheap-ite", true);
pull_ite_p.set_bool(":push-ite-arith", false);
pull_ite_p.set_bool(":local-ctx", true);
pull_ite_p.set_uint(":local-ctx-limit", 10000000);
params_ref ctx_simp_p;
ctx_simp_p.set_uint(":max-depth", 30);
ctx_simp_p.set_uint(":max-steps", 5000000);
params_ref lhs_p;
lhs_p.set_bool(":arith-lhs", true);
tactic * preamble_st = and_then(and_then(mk_simplify_tactic(m),
mk_propagate_values_tactic(m),
using_params(mk_ctx_simplify_tactic(m), ctx_simp_p),
using_params(mk_simplify_tactic(m), pull_ite_p)),
mk_solve_eqs_tactic(m),
mk_elim_uncnstr_tactic(m),
using_params(mk_simplify_tactic(m), lhs_p)
);
params_ref quasi_pb_p;
quasi_pb_p.set_uint(":lia2pb-max-bits", 64);
params_ref no_cut_p;
no_cut_p.set_uint(":arith-branch-cut-ratio", 10000000);
tactic * st = using_params(and_then(preamble_st,
or_else(mk_ilp_model_finder_tactic(m),
mk_pb_tactic(m),
and_then(fail_if_not(mk_quasi_pb_probe()),
using_params(mk_lia2sat_tactic(m), quasi_pb_p),
mk_fail_if_undecided_tactic()),
mk_bounded_tactic(m),
mk_smt_tactic())),
main_p);
st->updt_params(p);
return st;
}