Fixed a bug in LRUcache which prevented sizes >= 8.

Author: odersky

src/dotty/tools/dotc/core/Types.scala

@@ -327,7 +327,7 @@ object Types {
     }
 
     /** The member of this type with the given name  */
-    final def member(name: Name)(implicit ctx: Context): Denotation = /*>|>*/ track("member-" + name) /*<|<*/ {
+    final def member(name: Name)(implicit ctx: Context): Denotation = /*>|>*/ track("member") /*<|<*/ {
       findMember(name, widenIfUnstable, EmptyFlags)
     }
 

src/dotty/tools/dotc/util/LRUCache.scala

@@ -1,6 +1,7 @@
 package dotty.tools.dotc.util
 
 import reflect.ClassTag
+import annotation.tailrec
 
 /** A least-recently-used cache for Key -> Value computations
  *  It currently keeps the last 8 associations, but this can be
@@ -29,6 +30,7 @@ class LRUCache[Key >: Null : ClassTag, Value >: Null: ClassTag] {
    *  if key was not found.
    */
   def lookup(key: Key): Value = {
+    @tailrec
     def lookupNext(prev: Int, current: Int, nx: SixteenNibbles): Value = {
       val follow = nx(current)
       if (keys(current) == key) {
@@ -89,7 +91,7 @@ class LRUCache[Key >: Null : ClassTag, Value >: Null: ClassTag] {
 object LRUCache {
 
   /** The number of retained elements in the cache; must be at most 16. */
-  val Retained = 8
+  val Retained = 16
 
   /** The initial ring: 0 -> 1 -> ... -> 7 -> 0 */
   val initialRing =

src/dotty/tools/dotc/util/SixteenNibbles.scala

@@ -12,7 +12,7 @@ class SixteenNibbles(val bits: Long) extends AnyVal {
 
   def updated(idx: Int, value: Int): SixteenNibbles =
     new SixteenNibbles(
-      (bits & ~(Mask << (idx * Width))) |
+      (bits & ~(LongMask << (idx * Width))) |
       ((value & Mask).toLong << (idx * Width)))
 
   def elements: IndexedSeq[Int] = (0 until 16) map apply
@@ -24,4 +24,5 @@ class SixteenNibbles(val bits: Long) extends AnyVal {
 object SixteenNibbles {
   final val Width = 4
   final val Mask = (1 << Width) - 1
+  final val LongMask = Mask.toLong
 }