8281631: HashMap copy constructor and putAll can over-allocate table

src/java.base/share/classes/java/util/WeakHashMap.java

@@ -555,7 +555,7 @@ public void putAll(Map<? extends K, ? extends V> m) {
          * to at most one extra resize.
          */
         if (numKeysToBeAdded > threshold) {
-            int targetCapacity = (int)(numKeysToBeAdded / loadFactor + 1);
+            int targetCapacity = (int)Math.ceil(numKeysToBeAdded / loadFactor);
             if (targetCapacity > MAXIMUM_CAPACITY)
                 targetCapacity = MAXIMUM_CAPACITY;
             int newCapacity = table.length;

src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java

@@ -895,7 +895,7 @@ public ConcurrentHashMap(int initialCapacity,
             throw new IllegalArgumentException();
         if (initialCapacity < concurrencyLevel)   // Use at least as many bins
             initialCapacity = concurrencyLevel;   // as estimated threads
-        long size = (long)(1.0 + (long)initialCapacity / loadFactor);
+        long size = (long)Math.ceil(initialCapacity / (double)loadFactor);
         int cap = (size >= (long)MAXIMUM_CAPACITY) ?
             MAXIMUM_CAPACITY : tableSizeFor((int)size);
         this.sizeCtl = cap;
@@ -1463,7 +1463,7 @@ private void readObject(java.io.ObjectInputStream s)
         if (size == 0L)
             sizeCtl = 0;
         else {
-            long ts = (long)(1.0 + size / LOAD_FACTOR);
+            long ts = (long)Math.ceil(size / (double)LOAD_FACTOR);
             int n = (ts >= (long)MAXIMUM_CAPACITY) ?
                 MAXIMUM_CAPACITY : tableSizeFor((int)ts);
             @SuppressWarnings("unchecked")