From bb5118acbb9e9c74953a463601389ed635d874c8 Mon Sep 17 00:00:00 2001
From: "Christoph M. Wintersteiger" <cwinter@microsoft.com>
Date: Fri, 5 Feb 2016 13:53:35 +0000
Subject: [PATCH] Bugfix for  bv*div0 model construction.

---
 src/ast/bv_decl_plugin.h         | 15 +++++++++++++++
 src/ast/rewriter/bv_rewriter.cpp |  6 +++---
 src/ast/rewriter/bv_rewriter.h   |  6 ++++--
 src/model/model_evaluator.cpp    |  6 +++++-
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/ast/bv_decl_plugin.h b/src/ast/bv_decl_plugin.h
index 756ff1ed4..a4a0b1f57 100644
--- a/src/ast/bv_decl_plugin.h
+++ b/src/ast/bv_decl_plugin.h
@@ -354,6 +354,21 @@ public:
     bool has_sign_bit(rational const & n, unsigned bv_size) const;
     bool mult_inverse(rational const & n, unsigned bv_size, rational & result);
 
+    bool is_considered_uninterpreted(func_decl * f) {
+        if (f->get_family_id() != get_family_id())
+            return false;
+        switch (f->get_decl_kind()) {
+        case OP_BSDIV0:
+        case OP_BUDIV0:
+        case OP_BSREM0:
+        case OP_BUREM0:
+        case OP_BSMOD0:
+            return true;
+        default:
+            return false;
+        }
+        return false;
+    }
 };
 
 class bv_util : public bv_recognizers {
diff --git a/src/ast/rewriter/bv_rewriter.cpp b/src/ast/rewriter/bv_rewriter.cpp
index a45f20d9e..ca55db38f 100644
--- a/src/ast/rewriter/bv_rewriter.cpp
+++ b/src/ast/rewriter/bv_rewriter.cpp
@@ -694,7 +694,7 @@ br_status bv_rewriter::mk_bv_sdiv_core(expr * arg1, expr * arg2, bool hi_div0, e
         if (r2.is_zero()) {
             if (!hi_div0) {
                 result = m().mk_app(get_fid(), OP_BSDIV0, arg1);
-                return BR_DONE;
+                return BR_REWRITE1;
             }
             else {
                 // The "hardware interpretation" for (bvsdiv x 0) is (ite (bvslt x #x0000) #x0001 #xffff)
@@ -745,7 +745,7 @@ br_status bv_rewriter::mk_bv_udiv_core(expr * arg1, expr * arg2, bool hi_div0, e
         if (r2.is_zero()) {
             if (!hi_div0) {
                 result = m().mk_app(get_fid(), OP_BUDIV0, arg1);
-                return BR_DONE;
+                return BR_REWRITE1;
             }
             else {
                 // The "hardware interpretation" for (bvudiv x 0) is #xffff
@@ -808,7 +808,7 @@ br_status bv_rewriter::mk_bv_srem_core(expr * arg1, expr * arg2, bool hi_div0, e
         if (r2.is_zero()) {
             if (!hi_div0) {
                 result = m().mk_app(get_fid(), OP_BSREM0, arg1);
-                return BR_DONE;
+                return BR_REWRITE1;
             }
             else {
                 // The "hardware interpretation" for (bvsrem x 0) is x
diff --git a/src/ast/rewriter/bv_rewriter.h b/src/ast/rewriter/bv_rewriter.h
index 78d3fb4f1..f01743ca9 100644
--- a/src/ast/rewriter/bv_rewriter.h
+++ b/src/ast/rewriter/bv_rewriter.h
@@ -155,7 +155,7 @@ public:
     void updt_params(params_ref const & p);
 
     static void get_param_descrs(param_descrs & r);
-    
+
     void set_mkbv2num(bool f) { m_mkbv2num = f; }
 
     unsigned get_bv_size(expr * t) const {return m_util.get_bv_size(t); }
@@ -164,7 +164,7 @@ public:
     bool is_bv(expr * t) const { return m_util.is_bv(t); }
     expr * mk_numeral(numeral const & v, unsigned sz) { return m_util.mk_numeral(v, sz); }
     expr * mk_numeral(unsigned v, unsigned sz) { return m_util.mk_numeral(numeral(v), sz); }
-    
+
     br_status mk_app_core(func_decl * f, unsigned num_args, expr * const * args, expr_ref & result);
     void mk_app(func_decl * f, unsigned num_args, expr * const * args, expr_ref & result) {
         if (mk_app_core(f, num_args, args, result) == BR_FAILED)
@@ -174,6 +174,8 @@ public:
     br_status mk_eq_core(expr * lhs, expr * rhs, expr_ref & result);
 
     bool hi_div0() const { return m_hi_div0; }
+
+    bv_util & get_util() { return m_util; }
 };
 
 #endif
diff --git a/src/model/model_evaluator.cpp b/src/model/model_evaluator.cpp
index a565ea5ac..366678cf8 100644
--- a/src/model/model_evaluator.cpp
+++ b/src/model/model_evaluator.cpp
@@ -181,6 +181,7 @@ struct evaluator_cfg : public default_rewriter_cfg {
     }
 
     bool get_macro(func_decl * f, expr * & def, quantifier * & q, proof * & def_pr) {
+        TRACE("model_evaluator", tout << "get_macro for " << f->get_name() << " (model completion: " << m_model_completion << ")\n";);
 
         func_interp * fi = m_model.get_func_interp(f);
         if (fi != 0) {
@@ -199,7 +200,10 @@ struct evaluator_cfg : public default_rewriter_cfg {
             return true;
         }
 
-        if (f->get_family_id() == null_family_id && m_model_completion) {
+        if (m_model_completion &&
+            (f->get_family_id() == null_family_id ||
+             m_bv_rw.get_util().is_considered_uninterpreted(f)))
+        {
             sort * s   = f->get_range();
             expr * val = m_model.get_some_value(s);
             func_interp * new_fi = alloc(func_interp, m(), f->get_arity());