--- a/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java	Mon Jun 25 11:33:11 2018 -0400
+++ b/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java	Mon Jun 25 09:59:16 2018 -0700
@@ -702,12 +702,7 @@
      * See Hackers Delight, sec 3.2
      */
     private static final int tableSizeFor(int c) {
-        int n = c - 1;
-        n |= n >>> 1;
-        n |= n >>> 2;
-        n |= n >>> 4;
-        n |= n >>> 8;
-        n |= n >>> 16;
+        int n = -1 >>> Integer.numberOfLeadingZeros(c - 1);
         return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
     }
 
@@ -844,12 +839,7 @@
      * elements is negative
      */
     public ConcurrentHashMap(int initialCapacity) {
-        if (initialCapacity < 0)
-            throw new IllegalArgumentException();
-        int cap = ((initialCapacity >= (MAXIMUM_CAPACITY >>> 1)) ?
-                   MAXIMUM_CAPACITY :
-                   tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1));
-        this.sizeCtl = cap;
+        this(initialCapacity, LOAD_FACTOR, 1);
     }
 
     /**
@@ -883,8 +873,8 @@
 
     /**
      * Creates a new, empty map with an initial table size based on
-     * the given number of elements ({@code initialCapacity}), table
-     * density ({@code loadFactor}), and number of concurrently
+     * the given number of elements ({@code initialCapacity}), initial
+     * table density ({@code loadFactor}), and number of concurrently
      * updating threads ({@code concurrencyLevel}).
      *
      * @param initialCapacity the initial capacity. The implementation
@@ -1473,13 +1463,9 @@
         if (size == 0L)
             sizeCtl = 0;
         else {
-            int n;
-            if (size >= (long)(MAXIMUM_CAPACITY >>> 1))
-                n = MAXIMUM_CAPACITY;
-            else {
-                int sz = (int)size;
-                n = tableSizeFor(sz + (sz >>> 1) + 1);
-            }
+            long ts = (long)(1.0 + size / LOAD_FACTOR);
+            int n = (ts >= (long)MAXIMUM_CAPACITY) ?
+                MAXIMUM_CAPACITY : tableSizeFor((int)ts);
             @SuppressWarnings("unchecked")
             Node<K,V>[] tab = (Node<K,V>[])new Node<?,?>[n];
             int mask = n - 1;