Optimation: use AnyRefMap in GenASM javaName caches

These are a hotspot in the backend.

2 files changed, 4 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala b/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala
index eb40e1dbde..b03519ce7d 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala
@@ -171,10 +171,10 @@ abstract class GenASM extends SubComponent with BytecodeWriters with GenJVMASM {
 
   var pickledBytes = 0 // statistics
 
-  val javaNameCache = perRunCaches.newMap[Symbol, Name]()
+  val javaNameCache = perRunCaches.newAnyRefMap[Symbol, Name]()
 
   // unlike javaNameCache, reverseJavaName contains entries only for class symbols and their internal names.
-  val reverseJavaName = perRunCaches.newMap[String, Symbol]()
+  val reverseJavaName = perRunCaches.newAnyRefMap[String, Symbol]()
 
   private def mkFlags(args: Int*)         = args.foldLeft(0)(_ | _)
   private def hasPublicBitSet(flags: Int) = (flags & asm.Opcodes.ACC_PUBLIC) != 0
diff --git a/src/reflect/scala/reflect/internal/SymbolTable.scala b/src/reflect/scala/reflect/internal/SymbolTable.scala
index 571c4cfa5d..802bd18a4e 100644
--- a/src/reflect/scala/reflect/internal/SymbolTable.scala
+++ b/src/reflect/scala/reflect/internal/SymbolTable.scala
@@ -371,6 +371,8 @@ abstract class SymbolTable extends macros.Universe
     def newMap[K, V]()            = recordCache(mutable.HashMap[K, V]())
     def newSet[K]()               = recordCache(mutable.HashSet[K]())
     def newWeakSet[K <: AnyRef]() = recordCache(new WeakHashSet[K]())
+
+    def newAnyRefMap[K <: AnyRef, V]() = recordCache(mutable.AnyRefMap[K, V]())
     def newGeneric[T](f: => T): () => T = {
       val NoCached: T = null.asInstanceOf[T]
       var cached: T = NoCached