From eb64bf518df7a91094d99b7dfc7dfa8d199f04ae Mon Sep 17 00:00:00 2001
From: harrisonliew <harrisonliew@gmail.com>
Date: Wed, 29 May 2019 09:46:13 -0700
Subject: [PATCH] make analog attachment order fixed with linked hash map
 (#1089)

---
 src/main/scala/firrtl/passes/ExpandWhens.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/scala/firrtl/passes/ExpandWhens.scala b/src/main/scala/firrtl/passes/ExpandWhens.scala
index 956d54bc6c0..23c7956a316 100644
--- a/src/main/scala/firrtl/passes/ExpandWhens.scala
+++ b/src/main/scala/firrtl/passes/ExpandWhens.scala
@@ -256,7 +256,7 @@ object ExpandWhens extends Pass {
     case class AttachAcc(exprs: Seq[WrappedExpression], idx: Int)
     // Map from every attached expression to its corresponding AttachAcc
     //   (many keys will point to same value)
-    val attachMap = mutable.HashMap.empty[WrappedExpression, AttachAcc]
+    val attachMap = mutable.LinkedHashMap.empty[WrappedExpression, AttachAcc]
     for (Attach(_, es) <- attaches) {
       val exprs = es.map(we(_))
       val acc = exprs.map(attachMap.get(_)).flatten match {