2 files changed, 40 insertions, 5 deletions
diff --git a/lib/Expr/Expr.cpp b/lib/Expr/Expr.cpp
index d54b8f4d..baa85663 100644
--- a/lib/Expr/Expr.cpp
+++ b/lib/Expr/Expr.cpp
@@ -490,10 +490,45 @@ unsigned Array::computeHash() {
   unsigned res = 0;
   for (unsigned i = 0, e = name.size(); i != e; ++i)
     res = (res * Expr::MAGIC_HASH_CONSTANT) + name[i];
+  res = (res * Expr::MAGIC_HASH_CONSTANT) + size;
   hashValue = res;
   return hashValue; 
 }
 
+std::map<unsigned, std::vector<const Array *> *> Array::symbolicArraySingletonMap;
+
+const Array * Array::CreateArray(const std::string &_name, uint64_t _size,
+                                 const ref<ConstantExpr> *constantValuesBegin,
+                                 const ref<ConstantExpr> *constantValuesEnd,
+                                 Expr::Width _domain,
+				 Expr::Width _range) {
+
+  const Array * array = new Array(_name, _size, constantValuesBegin, constantValuesEnd, _domain,_range);
+  if (array->constantValues.size() == 0) { // symbolic array
+    unsigned hash = array->hash();
+    std::vector<const Array *> * bucket = Array::symbolicArraySingletonMap[hash];
+    if (bucket){
+      for (std::vector<const Array*>::const_iterator it = bucket->begin();
+	   it != bucket->end(); it ++){
+        const Array* prospect = *it;
+	if (prospect->size == array->size && prospect->name == array->name){
+    	  delete array;
+    	  return prospect;
+    	}
+      }
+      bucket->push_back(array);
+      return array;
+    } else {
+      bucket = new std::vector<const Array *>();
+      bucket->push_back(array);
+      Array::symbolicArraySingletonMap[hash] = bucket;
+      return array;
+    }
+  } else { // concrete array
+    return array;
+  }
+}
+
 /***/
 
 ref<Expr> ReadExpr::create(const UpdateList &ul, ref<Expr> index) {
diff --git a/lib/Expr/Parser.cpp b/lib/Expr/Parser.cpp
index aebce666..23a292fa 100644
--- a/lib/Expr/Parser.cpp
+++ b/lib/Expr/Parser.cpp
@@ -519,12 +519,12 @@ DeclResult ParserImpl::ParseArrayDecl() {
 
   // FIXME: Array should take domain and range.
   const Identifier *Label = GetOrCreateIdentifier(Name);
-  Array *Root;
+  const Array *Root;
   if (!Values.empty())
-    Root = new Array(Label->Name, Size.get(),
-                     &Values[0], &Values[0] + Values.size());
+    Root = Array::CreateArray(Label->Name, Size.get(),
+			      &Values[0], &Values[0] + Values.size());
   else
-    Root = new Array(Label->Name, Size.get());
+    Root = Array::CreateArray(Label->Name, Size.get());
   ArrayDecl *AD = new ArrayDecl(Label, Size.get(), 
                                 DomainType.get(), RangeType.get(), Root);
 
@@ -1306,7 +1306,7 @@ VersionResult ParserImpl::ParseVersionSpecifier() {
   VersionResult Res = ParseVersion();
   // Define update list to avoid use-of-undef errors.
   if (!Res.isValid()) {
-    Res = VersionResult(true, UpdateList(new Array("", 0), NULL));
+    Res = VersionResult(true, UpdateList(Array::CreateArray("", 0), NULL));
   }
   
   if (Label)