Merge pull request #1602 from freechipsproject/speed-up-dedup

Speed up Deduplication

1 files changed, 11 insertions, 3 deletions

diff --git a/src/main/scala/firrtl/transforms/Dedup.scala b/src/main/scala/firrtl/transforms/Dedup.scala
index d7769820..d0df9e32 100644
--- a/src/main/scala/firrtl/transforms/Dedup.scala
+++ b/src/main/scala/firrtl/transforms/Dedup.scala
@@ -74,7 +74,11 @@ class DedupModules extends Transform with DependencyAPIMigration with PreservesA
     val dedupMap = DedupModules.deduplicate(c, noDedups.toSet, annos, renameMap)
 
     // Use old module list to preserve ordering
-    val dedupedModules = c.modules.map(m => dedupMap(m.name)).distinct
+    // Lookup what a module deduped to, if its a duplicate, remove it
+    val dedupedModules = c.modules.flatMap { m =>
+      val mx = dedupMap(m.name)
+      if (mx.name == m.name) Some(mx) else None
+    }
 
     val cname = CircuitName(c.main)
     val map = dedupMap.map { case (from, to) =>
@@ -423,7 +427,11 @@ object DedupModules {
     val dedupedName2module = tag2name.map({ case (tag, name) => name -> DedupModules.dedupInstances(top, name, moduleMap, name2name, renameMap) })
 
     // Build map from original name to corresponding deduped module
-    val name2module = tag2all.flatMap({ case (tag, names) => names.map(n => n -> dedupedName2module(tag2name(tag))) })
+    // It is important to flatMap before looking up the DefModules so that they aren't hashed
+    val name2module: Map[String, DefModule] =
+      tag2all.flatMap { case (tag, names) => names.map(_ -> tag) }
+             .mapValues(tag => dedupedName2module(tag2name(tag)))
+             .toMap
 
     // Build renameMap
     val indexedTargets = mutable.HashMap[String, IndexedSeq[ReferenceTarget]]()
@@ -435,7 +443,7 @@ object DedupModules {
       }
     }
 
-    name2module.toMap
+    name2module
   }
 
   def computeIndexedNames(main: String, m: DefModule): IndexedSeq[ReferenceTarget] = {