prioritize decisions on variables of larger bit width

src/math/polysat/pvar_queue.h

@@ -3,11 +3,11 @@ Copyright (c) 2011 Microsoft Corporation
 
 Module Name:
 
-    var_queue.h
+    pvar_queue.h
 
 Abstract:
 
-    SAT variable priority queue.
+    polysat variable priority queue.
 
 Author:
 
@@ -21,61 +21,63 @@ Revision History:
 #include "util/heap.h"
 
 
-    
-class var_queue {
+class pvar_queue {
     typedef unsigned var;
 
-    struct lt {
-        svector<unsigned> & m_activity;
-    lt(svector<unsigned> & act):m_activity(act) {}
-        bool operator()(var v1, var v2) const { return m_activity[v1] > m_activity[v2]; }
+    class lt {
+        unsigned_vector const& m_size;
+        unsigned_vector const& m_activity;
+    public:
+        lt(unsigned_vector const& sz, unsigned_vector const& act): m_size(sz), m_activity(act) {}
+        bool operator()(var v1, var v2) const {
+            return m_size[v1] > m_size[v2]
+                || (m_size[v1] == m_size[v2] && m_activity[v1] > m_activity[v2]);
+        }
     };
-    heap<lt>  m_queue;
+
+    heap<lt> m_queue;
 public:
 
-    
-    var_queue(svector<unsigned> & act):m_queue(128, lt(act)) {}
-    
+    pvar_queue(unsigned_vector const& sz, unsigned_vector const& act): m_queue(128, lt(sz, act)) {}
+
     void activity_increased_eh(var v) {
         if (m_queue.contains(v))
             m_queue.decreased(v);
     }
-    
+
     void activity_changed_eh(var v, bool up) {
         if (m_queue.contains(v)) {
-            if (up) 
+            if (up)
                 m_queue.decreased(v);
-            else 
+            else
                 m_queue.increased(v);
         }
     }
-    
+
     void mk_var_eh(var v) {
         m_queue.reserve(v+1);
         unassign_var_eh(v);
     }
-    
+
     void del_var_eh(var v) {
         if (m_queue.contains(v))
             m_queue.erase(v);
     }
-    
+
     void unassign_var_eh(var v) {
         if (!m_queue.contains(v))
             m_queue.insert(v);
     }
-    
+
     void reset() {
         m_queue.reset();
     }
-    
+
     bool empty() const { return m_queue.empty(); }
-    
+
     var next_var() { SASSERT(!empty()); return m_queue.erase_min(); }
-    
+
     var min_var() { SASSERT(!empty()); return m_queue.min_value(); }
-    
-    bool more_active(var v1, var v2) const { return m_queue.less_than(v1, v2); }
 
     std::ostream& display(std::ostream& out) const {
         bool first = true;
@@ -95,6 +97,6 @@ public:
     const_iterator end() const { return m_queue.end(); }
 };
 
-inline std::ostream& operator<<(std::ostream& out, var_queue const& queue) {
+inline std::ostream& operator<<(std::ostream& out, pvar_queue const& queue) {
     return queue.display(out);
 }

src/math/polysat/solver.cpp

@@ -55,7 +55,7 @@ namespace polysat {
         m_simplify(*this),
         m_restart(*this),
         m_bvars(*this),
-        m_free_pvars(m_activity),
+        m_free_pvars(m_size, m_activity),
         m_constraints(*this),
         m_names(*this),
         m_slicing(*this),

src/math/polysat/solver.h

@@ -34,6 +34,7 @@ Author:
 #include "math/polysat/search_state.h"
 #include "math/polysat/assignment.h"
 #include "math/polysat/trail.h"
+#include "math/polysat/pvar_queue.h"
 #include "math/polysat/viable.h"
 #include "math/polysat/log.h"
 #include <limits>
@@ -170,7 +171,7 @@ namespace polysat {
         simplify                 m_simplify;
         restart                  m_restart;
         bool_var_manager         m_bvars;       // Map boolean variables to constraints
-        var_queue                m_free_pvars;  // free poly vars
+        pvar_queue               m_free_pvars;  // free poly vars
         stats                    m_stats;
         random_gen               m_rand;
 

src/math/polysat/types.h

@@ -16,7 +16,6 @@ Author:
 #include "util/map.h"
 #include "util/rlimit.h"
 #include "util/scoped_ptr_vector.h"
-#include "util/var_queue.h"
 #include "util/ref_vector.h"
 #include "util/sat_literal.h"
 #include "math/dd/dd_pdd.h"