Some performance tweaks to ResizableArray.

1 files changed, 9 insertions, 8 deletions

diff --git a/src/library/scala/collection/mutable/ResizableArray.scala b/src/library/scala/collection/mutable/ResizableArray.scala
index 9cc19cd8e2..f44efb2329 100644
--- a/src/library/scala/collection/mutable/ResizableArray.scala
+++ b/src/library/scala/collection/mutable/ResizableArray.scala
@@ -31,7 +31,6 @@ trait ResizableArray[A] extends IndexedSeq[A]
 
   protected def initialSize: Int = 16
   protected var array: Array[AnyRef] = new Array[AnyRef](math.max(initialSize, 1))
-
   protected var size0: Int = 0
 
   //##########################################################################
@@ -51,9 +50,13 @@ trait ResizableArray[A] extends IndexedSeq[A]
     array(idx) = elem.asInstanceOf[AnyRef]
   }
 
-  override def foreach[U](f: A =>  U) {
+  override def foreach[U](f: A => U) {
     var i = 0
-    while (i < size) {
+    // size is cached here because profiling reports a lot of time spent calling
+    // it on every iteration.  I think it's likely a profiler ghost but it doesn't
+    // hurt to lift it into a local.
+    val top = size
+    while (i < top) {
       f(array(i).asInstanceOf[A])
       i += 1
     }
@@ -91,12 +94,10 @@ trait ResizableArray[A] extends IndexedSeq[A]
       var newsize = array.length * 2
       while (n > newsize)
         newsize = newsize * 2
-    // println("Internal array before, size " + size0 + ": " + array.toList)
+
       val newar: Array[AnyRef] = new Array(newsize)
-      Array.copy(array, 0, newar, 0, size0)
-    // println("Internal array after,  size " + size0 + ": " + array.toList)
+      compat.Platform.arraycopy(array, 0, newar, 0, size0)
       array = newar
-    // println("New array after,  size      " + size0 + ": " + newar.toList)
     }
   }
 
@@ -111,7 +112,7 @@ trait ResizableArray[A] extends IndexedSeq[A]
   /** Move parts of the array.
    */
   protected def copy(m: Int, n: Int, len: Int) {
-    Array.copy(array, m, array, n, len)
+    compat.Platform.arraycopy(array, m, array, n, len)
   }
 }