Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/qe_bv_plugin.cpp

@@ -0,0 +1,97 @@
+/*++
+Copyright (c) 2010 Microsoft Corporation
+
+Module Name:
+
+    bv_plugin.cpp
+
+Abstract:
+
+    Eliminate Bit-vector variable from formula
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2010-02-19
+
+Revision History:
+
+Notes:
+
+
+--*/
+
+#include "qe.h"
+#include "expr_replacer.h"
+#include "bv_decl_plugin.h"
+#include "model_evaluator.h"
+
+namespace qe {
+
+    class bv_plugin : public qe_solver_plugin {
+        scoped_ptr<expr_replacer> m_replace;
+        bv_util      m_bv;
+    public:
+        bv_plugin(i_solver_context& ctx, ast_manager& m): 
+            qe_solver_plugin(m, m.get_family_id("bv"), ctx),
+            m_replace(mk_default_expr_replacer(m)),
+            m_bv(m)
+        {}
+
+        virtual void assign(contains_app& x, expr* fml, rational const& vl) {
+        }
+
+        virtual bool get_num_branches(contains_app& x, expr* fml, rational& nb) {
+            unsigned sz = m_bv.get_bv_size(x.x());
+            nb = power(rational(2), sz);
+            return true;
+        }
+
+        virtual void subst(contains_app& x, rational const& vl, expr_ref& fml, expr_ref* def) {
+            app_ref c(m_bv.mk_numeral(vl, m_bv.get_bv_size(x.x())), m);
+            m_replace->apply_substitution(x.x(), c, 0, fml);
+            if (def) {
+                *def = m_bv.mk_numeral(vl, m_bv.get_bv_size(x.x()));
+            }
+        }
+
+        virtual bool project(contains_app& x, model_ref& model, expr_ref& fml) {
+            model_evaluator model_eval(*model);
+            expr_ref val_x(m);
+            rational val(0);
+            unsigned bv_size;
+            model_eval(x.x(), val_x);
+            m_bv.is_numeral(val_x, val, bv_size);
+            subst(x, val, fml, 0);
+            return true;
+        }
+
+        virtual unsigned get_weight(contains_app& contains_x, expr* fml) {
+            return 2;
+        }
+
+        bool solve(conj_enum& conjs, expr* fml) { return false; }                   
+
+        virtual bool is_uninterpreted(app* f) {
+            switch(f->get_decl_kind()) {
+            case OP_BSDIV0: 
+            case OP_BUDIV0:
+            case OP_BSREM0:
+            case OP_BUREM0:
+            case OP_BSMOD0:
+            case OP_BSDIV_I:
+            case OP_BUDIV_I:
+            case OP_BSREM_I:
+            case OP_BUREM_I:
+            case OP_BSMOD_I:
+                return true;
+            default:
+                return false;
+            }
+            return false;
+        }
+    };
+    
+    qe_solver_plugin* mk_bv_plugin(i_solver_context& ctx) {
+        return alloc(bv_plugin, ctx, ctx.get_manager());
+    }
+}