first attempts at getting to the bvsls from opt_context.

scripts/mk_project.py

@@ -71,7 +71,7 @@ def init_project_def():
     add_lib('ufbv_tactic', ['normal_forms', 'core_tactics', 'macros', 'smt_tactic', 'rewriter'], 'tactic/ufbv')
     add_lib('portfolio', ['smtlogic_tactics', 'ufbv_tactic', 'fpa', 'aig_tactic', 'fp',  'qe','sls_tactic', 'subpaving_tactic'], 'tactic/portfolio')
     add_lib('smtparser', ['portfolio'], 'parsers/smt')
-    add_lib('opt', ['smt', 'smtlogic_tactics'], 'opt')
+    add_lib('opt', ['smt', 'smtlogic_tactics', 'sls_tactic'], 'opt')
     API_files = ['z3_api.h', 'z3_algebraic.h', 'z3_polynomial.h', 'z3_rcf.h']
     add_lib('api', ['portfolio', 'user_plugin', 'smtparser', 'realclosure','interp','opt'],
             includes2install=['z3.h', 'z3_v1.h', 'z3_macros.h'] + API_files)

src/opt/bvsls_opt_solver.cpp

@@ -0,0 +1,123 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    bvsls_opt_solver.cpp
+
+Abstract:
+
+    Uses the bvsls engine for optimization
+
+Author:
+
+    Christoph (cwinter) 2014-3-28
+
+Notes:
+
+--*/
+
+#include "bvsls_opt_solver.h"
+
+namespace opt {
+
+    bvsls_opt_solver::bvsls_opt_solver(ast_manager & m, params_ref const & p) :
+        opt_solver(m, p, symbol("QF_BV")),
+        m_manager(m),
+        m_params(p),
+        m_engine(m, p)
+    {
+    }
+
+    bvsls_opt_solver::~bvsls_opt_solver()
+    {        
+    }
+
+    void bvsls_opt_solver::updt_params(params_ref & p)
+    {
+        opt_solver::updt_params(p);
+        m_engine.updt_params(p);
+    }
+
+    void bvsls_opt_solver::collect_param_descrs(param_descrs & r)
+    {
+        opt_solver::collect_param_descrs(r);
+    }
+
+    void bvsls_opt_solver::collect_statistics(statistics & st) const
+    {
+        opt_solver::collect_statistics(st);
+    }
+
+    void bvsls_opt_solver::assert_expr(expr * t) {
+        m_engine.assert_expr(t);
+    }
+
+    void bvsls_opt_solver::push_core()
+    {
+        opt_solver::push_core();
+    }
+
+    void bvsls_opt_solver::pop_core(unsigned n)
+    {   
+        opt_solver::pop_core(n);
+    }
+
+    lbool bvsls_opt_solver::check_sat_core(unsigned num_assumptions, expr * const * assumptions)
+    {
+        SASSERT(num_assumptions == 0);
+        SASSERT(assumptions == 0);        
+        return m_engine();
+    }
+
+    void bvsls_opt_solver::get_unsat_core(ptr_vector<expr> & r)
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+
+    void bvsls_opt_solver::get_model(model_ref & m)
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+
+    proof * bvsls_opt_solver::get_proof()
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+
+    std::string bvsls_opt_solver::reason_unknown() const
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+
+    void bvsls_opt_solver::get_labels(svector<symbol> & r)
+    {
+        opt_solver::get_labels(r);
+    }
+
+    void bvsls_opt_solver::set_cancel(bool f)
+    {
+        opt_solver::set_cancel(f);
+        m_engine.set_cancel(f);
+    }
+
+    void bvsls_opt_solver::set_progress_callback(progress_callback * callback)
+    {
+        opt_solver::set_progress_callback(callback);
+    }
+
+    unsigned bvsls_opt_solver::get_num_assertions() const
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+
+    expr * bvsls_opt_solver::get_assertion(unsigned idx) const
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+
+    void bvsls_opt_solver::display(std::ostream & out) const
+    {
+        NOT_IMPLEMENTED_YET();
+    }
+}

src/opt/bvsls_opt_solver.h

@@ -0,0 +1,57 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    bvsls_opt_solver.h
+
+Abstract:
+
+    Uses the bvsls engine for optimization
+
+Author:
+
+    Christoph (cwinter) 2014-3-28
+
+Notes:
+
+--*/
+#ifndef _BVSLS_OPT_SOLVER_H_
+#define _BVSLS_OPT_SOLVER_H_
+
+#include "bvsls_opt_engine.h"
+#include "opt_solver.h"
+
+namespace opt {
+
+    class bvsls_opt_solver : public opt_solver {
+        ast_manager       & m_manager;
+        params_ref  const & m_params;
+        bvsls_opt_engine    m_engine;
+
+    public:
+        bvsls_opt_solver(ast_manager & m, params_ref const & p);
+        virtual ~bvsls_opt_solver();
+
+        virtual void updt_params(params_ref & p);
+        virtual void collect_param_descrs(param_descrs & r);
+        virtual void collect_statistics(statistics & st) const;
+        virtual void assert_expr(expr * t);
+        virtual void push_core();
+        virtual void pop_core(unsigned n);
+        virtual lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions);
+        virtual void get_unsat_core(ptr_vector<expr> & r);
+        virtual void get_model(model_ref & m);
+        virtual proof * get_proof();
+        virtual std::string reason_unknown() const;
+        virtual void get_labels(svector<symbol> & r);
+        virtual void set_cancel(bool f);
+        virtual void set_progress_callback(progress_callback * callback);
+        virtual unsigned get_num_assertions() const;
+        virtual expr * get_assertion(unsigned idx) const;
+        virtual void display(std::ostream & out) const;
+    };
+
+}
+
+#endif

src/opt/opt_context.cpp

@@ -33,6 +33,9 @@ Notes:
 #include "elim_uncnstr_tactic.h"
 #include "tactical.h"
 #include "model_smt2_pp.h"
+#include "card2bv_tactic.h"
+#include "bvsls_opt_solver.h"
+#include "nnf_tactic.h"
 
 namespace opt {
 
@@ -130,12 +133,13 @@ namespace opt {
     }
 
     lbool context::optimize() {
-        opt_solver& s = get_solver();        
-        m_optsmt.reset();
+        m_optsmt.reset();        
         normalize();
         internalize();
+        opt_solver& s = get_solver();        
         solver::scoped_push _sp(s);
         for (unsigned i = 0; i < m_hard_constraints.size(); ++i) {
+            TRACE("opt", tout << "Hard constraint: " << mk_ismt2_pp(m_hard_constraints[i].get(), m) << std::endl;);
             s.assert_expr(m_hard_constraints[i].get());
         }
 
@@ -359,7 +363,19 @@ namespace opt {
                      mk_simplify_tactic(m));   
         opt_params optp(m_params);
         tactic_ref tac2, tac3;
-        if (optp.elim_01()) {
+        if (optp.engine() == "bvsls") {
+            tac2 = mk_elim01_tactic(m);
+            tac3 = mk_lia2card_tactic(m);
+            params_ref lia_p;
+            lia_p.set_bool("compile_equality", optp.pb_compile_equality());
+            tac3->updt_params(lia_p);
+            m_simplify = and_then(tac0.get(), tac2.get(), tac3.get(),
+                                  mk_card2bv_tactic(m),                                  
+                                  mk_simplify_tactic(m),                                  
+                                  mk_nnf_tactic(m));
+            m_solver = alloc(bvsls_opt_solver, m, m_params);
+        }
+        else if (optp.elim_01()) {
             tac2 = mk_elim01_tactic(m);
             tac3 = mk_lia2card_tactic(m);
             params_ref lia_p;

src/tactic/arith/card2bv_tactic.cpp

@@ -27,6 +27,7 @@ Notes:
 
 class card2bv_rewriter {
     ast_manager& m;
+    arith_util   au;
     pb_util      pb;
     bv_util      bv;
 
@@ -43,51 +44,102 @@ class card2bv_rewriter {
 public:
     card2bv_rewriter(ast_manager& m):
         m(m),
+        au(m),
         pb(m),
         bv(m)
     {}
 
     br_status mk_app_core(func_decl * f, unsigned sz, expr * const* args, expr_ref & result) {
-        if (f->get_family_id() != pb.get_family_id()) {
+        if (f->get_family_id() == null_family_id) {
+            if (sz == 1) {
+                // Expecting minimize/maximize.
+                func_decl_ref fd(m);
+                fd = m.mk_func_decl(f->get_name(), m.get_sort(args[0]), f->get_range());
+                result = m.mk_app(fd.get(), args[0]);
+                return BR_DONE;
+            }
+            else
+                return BR_FAILED;
+        }
+        else if (f->get_family_id() == m.get_basic_family_id()) {
+            result = m.mk_app(f, sz, args);
+            return BR_DONE;
+        }
+        else if (f->get_family_id() == pb.get_family_id()) {
+            expr_ref zero(m), a(m), b(m);
+            expr_ref_vector es(m);
+            unsigned bw = get_num_bits(f);
+            zero = bv.mk_numeral(rational(0), bw);
+            for (unsigned i = 0; i < sz; ++i) {
+                es.push_back(m.mk_ite(args[i], bv.mk_numeral(pb.get_coeff(f, i), bw), zero));
+            }
+            switch (es.size()) {
+            case 0:  a = zero; break;
+            case 1:  a = es[0].get(); break;
+            default:
+                a = es[0].get();
+                for (unsigned i = 1; i < es.size(); ++i) {
+                    a = bv.mk_bv_add(a, es[i].get());
+                }
+                break;
+            }
+            b = bv.mk_numeral(pb.get_k(f), bw);
+
+            switch (f->get_decl_kind()) {
+            case OP_AT_MOST_K:
+            case OP_PB_LE:
+                UNREACHABLE();
+                result = bv.mk_ule(a, b);
+                return BR_DONE;
+            case OP_AT_LEAST_K:
+                UNREACHABLE();
+            case OP_PB_GE:
+                result = bv.mk_ule(b, a);
+                return BR_DONE;
+            case OP_PB_EQ:
+                result = m.mk_eq(a, b);
+                return BR_DONE;
+            default:
+                UNREACHABLE();
+            }
             return BR_FAILED;
         }
-        expr_ref zero(m), a(m), b(m);
-        expr_ref_vector es(m);
-        unsigned bw = get_num_bits(f);
-        zero = bv.mk_numeral(rational(0), bw);
-        for (unsigned i = 0; i < sz; ++i) {
-            es.push_back(m.mk_ite(args[i], bv.mk_numeral(pb.get_coeff(f, i), bw), zero));
-        }
-        switch (es.size()) {
-        case 0:  a = zero; break;
-        case 1:  a = es[0].get(); break;
-        default: 
-            a = es[0].get();
-            for (unsigned i = 1; i < es.size(); ++i) {
-                a = bv.mk_bv_add(a, es[i].get());
-            }
-            break;
-        }
-        b = bv.mk_numeral(pb.get_k(f), bw);
+        else if (f->get_family_id() == au.get_family_id())
+        {
+            if (f->get_decl_kind() == OP_ADD) {
+                bool all_ite_01 = true;
+                unsigned bits = 0;
+                for (unsigned i = 0; i < sz; i++) {
+                    rational val1, val2;
+                    if (au.is_int(args[i]) && au.is_numeral(args[i], val1)) {
+                        bits += val1.get_num_bits();
+                    }
+                    else if (m.is_ite(args[i]) &&
+                             au.is_numeral(to_app(args[i])->get_arg(1), val1) && val1.is_one() &&
+                             au.is_numeral(to_app(args[i])->get_arg(2), val2) && val2.is_zero()) {
+                        bits++;                        
+                    }
+                    else
+                        return BR_FAILED;
+                }
 
-        switch(f->get_decl_kind()) {
-        case OP_AT_MOST_K: 
-        case OP_PB_LE: 
-            UNREACHABLE();
-            result = bv.mk_ule(a, b);
-            return BR_DONE; 
-        case OP_AT_LEAST_K: 
-            UNREACHABLE();
-        case OP_PB_GE:
-            result = bv.mk_ule(b, a);
-            return BR_DONE;
-        case OP_PB_EQ: 
-            result = m.mk_eq(a, b);
-            return BR_DONE;
-        default:
-            UNREACHABLE();
+                result = 0;
+                for (unsigned i = 0; i < sz; i++) {
+                    rational val1, val2;
+                    expr * q;
+                    if (au.is_int(args[i]) && au.is_numeral(args[i], val1))
+                        q = bv.mk_numeral(val1, bits);
+                    else
+                        q = m.mk_ite(to_app(args[i])->get_arg(0), bv.mk_numeral(1, bits), bv.mk_numeral(0, bits));
+                    result = (i == 0) ? q : bv.mk_bv_add(result.get(), q);
+                }                
+                return BR_DONE;
+            }
+            else 
+                return BR_FAILED;
         }
-        return BR_FAILED;
+        else
+            return BR_FAILED;
     }
 };
 
@@ -151,7 +203,7 @@ public:
                             model_converter_ref & mc, 
                             proof_converter_ref & pc,
                             expr_dependency_ref & core) {
-        TRACE("pb2bv", g->display(tout););
+        TRACE("card2bv-before", g->display(tout););
         SASSERT(g->is_well_sorted());
         fail_if_proof_generation("card2bv", g);
         mc = 0; pc = 0; core = 0; result.reset();
@@ -168,6 +220,7 @@ public:
         expr_ref new_f1(m), new_f2(m);
         for (unsigned idx = 0; idx < size; idx++) {
             m_rw1(g->form(idx), new_f1);
+            TRACE("card2bv", tout << "Rewriting " << mk_ismt2_pp(new_f1.get(), m) << std::endl;);
             m_rw2(new_f1, new_f2);
             g->update(idx, new_f2);
         }

src/tactic/sls/bvsls_opt_engine.cpp

@@ -0,0 +1,69 @@
+/*++
+Copyright (c) 2014 Microsoft Corporation
+
+Module Name:
+
+    bvsls_opt_engine.cpp
+
+Abstract:
+
+    Optimization extensions to bvsls
+
+Author:
+
+    Christoph (cwinter) 2014-03-28
+
+Notes:
+
+--*/
+#include "bvsls_opt_engine.h"
+
+bvsls_opt_engine::bvsls_opt_engine(ast_manager & m, params_ref const & p) :
+    sls_engine(m, p)
+{
+}
+
+bvsls_opt_engine::~bvsls_opt_engine()
+{    
+}
+
+bvsls_opt_engine::optimization_result bvsls_opt_engine::optimize(expr_ref const & objective)
+{
+    SASSERT(m_bv_util.is_bv(objective));
+    m_tracker.initialize(m_assertions);
+    m_restart_limit = _RESTART_LIMIT_;
+
+    optimization_result res(m_manager);
+
+    do {
+        checkpoint();
+
+        IF_VERBOSE(1, verbose_stream() << "Optimizing... restarts left:" << (m_max_restarts - m_stats.m_restarts) << std::endl; );
+        res.is_sat = search();
+
+        if (res.is_sat == l_undef)
+        {
+#if _RESTART_INIT_
+            m_tracker.randomize();
+#else
+            m_tracker.reset(m_assertions);
+#endif
+        }
+    } while (m_stats.m_stopwatch.get_current_seconds() < _TIMELIMIT_ &&
+             res.is_sat != l_true && m_stats.m_restarts++ < m_max_restarts);    
+
+    if (res.is_sat)
+        res.optimum = maximize(objective);
+
+    return res;
+}
+
+expr_ref bvsls_opt_engine::maximize(expr_ref const & objective)
+{
+    expr_ref res(m_manager);
+    res = m_bv_util.mk_numeral(0, m_bv_util.get_bv_size(objective));
+
+    // TODO.
+
+    return res;
+}

src/tactic/sls/bvsls_opt_engine.h

@@ -0,0 +1,42 @@
+/*++
+Copyright (c) 2014 Microsoft Corporation
+
+Module Name:
+
+    bvsls_opt_engine.h
+
+Abstract:
+
+    Optimization extensions to bvsls
+
+Author:
+
+    Christoph (cwinter) 2014-03-28
+
+Notes:
+
+--*/
+#ifndef _BVSLS_OPT_ENGINE_H_
+#define _BVSLS_OPT_ENGINE_H_
+
+#include "sls_engine.h"
+
+class bvsls_opt_engine : public sls_engine {
+public:
+    bvsls_opt_engine(ast_manager & m, params_ref const & p);
+    ~bvsls_opt_engine();
+
+    class optimization_result {
+    public:
+        lbool is_sat;
+        expr_ref optimum;
+        optimization_result(ast_manager & m) : is_sat(l_undef), optimum(m) {}
+    };
+
+    optimization_result optimize(expr_ref const & objective);
+
+protected:
+    expr_ref maximize(expr_ref const & objective);
+};
+
+#endif