Dagification of output expressions.

By default, common subexpressions are dagified if they appear > 1 time and are not constants or variables.
This can be changed with --default-expr-dag=N --- N is a threshold such that if the subexpression occurs > N
times, it is dagified; a setting of 0 turns off dagification entirely.

If you notice strange dumping behavior (taking too long to print anything, e.g.), revert to the old behavior
with --default-expr-dag=0 and let me know of the problem.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/theory/substitutions.h b/src/theory/substitutions.h
index c32dee635..ee2a15f6f 100644
--- a/src/theory/substitutions.h
+++ b/src/theory/substitutions.h
@@ -148,10 +148,14 @@ public:
     return d_substitutions.end();
   }
 
+  bool empty() const {
+    return d_substitutions.empty();
+  }
+
   // NOTE [MGD]: removed clear() and swap() from the interface
   // when this data structure became context-dependent
   // because they weren't used---and it's not clear how they
-  // should // best interact with cache invalidation on context
+  // should best interact with cache invalidation on context
   // pops.
 
   /**
@@ -159,7 +163,7 @@ public:
    */
   void print(std::ostream& out) const;
 
-};
+};/* class SubstitutionMap */
 
 inline std::ostream& operator << (std::ostream& out, const SubstitutionMap& subst) {
   subst.print(out);