Fixed infinite loop for finding connect origin in ReplSeqMem (#300)

* Addressed the fact that a node can be connected to itself (updating reg)

1 files changed, 7 insertions, 2 deletions

diff --git a/src/main/scala/firrtl/passes/AnnotateMemMacros.scala b/src/main/scala/firrtl/passes/AnnotateMemMacros.scala
index af58c7c5..1d415529 100644
--- a/src/main/scala/firrtl/passes/AnnotateMemMacros.scala
+++ b/src/main/scala/firrtl/passes/AnnotateMemMacros.scala
@@ -45,7 +45,12 @@ object AnalysisUtils {
   // limitation: only works in a module (stops @ module inputs)
   // TODO: more thorough (i.e. a + 0 = a)
   def getConnectOrigin(connects: Map[String, Expression], node: String): Expression = {
-    if (connects contains node) getOrigin(connects, connects(node))
+    if (connects contains node) {
+      val exp = connects(node)
+      // handles case when a node is connected to itself (connecting reg output back to input)
+      if (exp.serialize == node) exp
+      else getOrigin(connects, exp)
+    }
     else EmptyExpression
   }
 
@@ -142,4 +147,4 @@ object AnnotateMemMacros extends Pass {
 
 }
 
-// TODO: Add floorplan info?
+// TODO: Add floorplan info?
\ No newline at end of file