--- jsr166/src/main/java/util/ArrayList.java	2017/05/06 06:49:45	1.50
+++ jsr166/src/main/java/util/ArrayList.java	2017/05/14 21:44:25	1.51
@@ -515,15 +515,10 @@ public class ArrayList<E> extends Abstra
      */
     public E remove(int index) {
         Objects.checkIndex(index, size);
+        final Object[] es = elementData;
 
-        modCount++;
-        E oldValue = elementData(index);
-
-        int numMoved = size - index - 1;
-        if (numMoved > 0)
-            System.arraycopy(elementData, index+1, elementData, index,
-                             numMoved);
-        elementData[--size] = null; // clear to let GC do its work
+        @SuppressWarnings("unchecked") E oldValue = (E) es[index];
+        fastRemove(es, index);
 
         // checkInvariants();
         return oldValue;
@@ -543,33 +538,35 @@ public class ArrayList<E> extends Abstra
      * @return {@code true} if this list contained the specified element
      */
     public boolean remove(Object o) {
-        if (o == null) {
-            for (int index = 0; index < size; index++)
-                if (elementData[index] == null) {
-                    fastRemove(index);
-                    return true;
-                }
-        } else {
-            for (int index = 0; index < size; index++)
-                if (o.equals(elementData[index])) {
-                    fastRemove(index);
-                    return true;
-                }
+        final Object[] es = elementData;
+        final int size = this.size;
+        int i = 0;
+        found: {
+            if (o == null) {
+                for (; i < size; i++)
+                    if (es[i] == null)
+                        break found;
+            } else {
+                for (; i < size; i++)
+                    if (o.equals(es[i]))
+                        break found;
+            }
+            return false;
         }
-        return false;
+        fastRemove(es, i);
+        return true;
     }
 
     /**
      * Private remove method that skips bounds checking and does not
      * return the value removed.
      */
-    private void fastRemove(int index) {
+    private void fastRemove(Object[] es, int i) {
         modCount++;
-        int numMoved = size - index - 1;
-        if (numMoved > 0)
-            System.arraycopy(elementData, index+1, elementData, index,
-                             numMoved);
-        elementData[--size] = null; // clear to let GC do its work
+        final int newSize;
+        if ((newSize = size - 1) > i)
+            System.arraycopy(es, i + 1, es, i, newSize - i);
+        es[size = newSize] = null;
     }
 
     /**