--- a/src/java.base/share/classes/java/util/concurrent/ConcurrentLinkedDeque.java	Thu Nov 09 16:07:21 2017 -0800
+++ b/src/java.base/share/classes/java/util/concurrent/ConcurrentLinkedDeque.java	Thu Nov 09 16:10:46 2017 -0800
@@ -695,8 +695,9 @@
      * stale pointer that is now off the list.
      */
     final Node<E> pred(Node<E> p) {
-        Node<E> q = p.prev;
-        return (p == q) ? last() : q;
+        if (p == (p = p.prev))
+            p = last();
+        return p;
     }
 
     /**
@@ -867,31 +868,31 @@
 
     public E peekFirst() {
         restart: for (;;) {
-            for (Node<E> first = first(), p = first;;) {
-                final E item;
-                if ((item = p.item) != null) {
-                    // recheck for linearizability
-                    if (first.prev != null) continue restart;
-                    return item;
-                }
-                if ((p = succ(p)) == null)
-                    return null;
+            E item;
+            Node<E> first = first(), p = first;
+            while ((item = p.item) == null) {
+                if (p == (p = p.next)) continue restart;
+                if (p == null)
+                    break;
             }
+            // recheck for linearizability
+            if (first.prev != null) continue restart;
+            return item;
         }
     }
 
     public E peekLast() {
         restart: for (;;) {
-            for (Node<E> last = last(), p = last;;) {
-                final E item;
-                if ((item = p.item) != null) {
-                    // recheck for linearizability
-                    if (last.next != null) continue restart;
-                    return item;
-                }
-                if ((p = pred(p)) == null)
-                    return null;
+            E item;
+            Node<E> last = last(), p = last;
+            while ((item = p.item) == null) {
+                if (p == (p = p.prev)) continue restart;
+                if (p == null)
+                    break;
             }
+            // recheck for linearizability
+            if (last.next != null) continue restart;
+            return item;
         }
     }
 
@@ -921,8 +922,11 @@
                         return item;
                     }
                 }
-                if ((p = succ(p)) == null)
+                if (p == (p = p.next)) continue restart;
+                if (p == null) {
+                    if (first.prev != null) continue restart;
                     return null;
+                }
             }
         }
     }
@@ -939,8 +943,11 @@
                         return item;
                     }
                 }
-                if ((p = pred(p)) == null)
+                if (p == (p = p.prev)) continue restart;
+                if (p == null) {
+                    if (last.next != null) continue restart;
                     return null;
+                }
             }
         }
     }