diff -r 4944950606ef -r 29e165bdf669 src/java.base/share/classes/java/nio/X-Buffer.java.template
--- a/src/java.base/share/classes/java/nio/X-Buffer.java.template	Wed Dec 20 09:14:06 2017 -0800
+++ b/src/java.base/share/classes/java/nio/X-Buffer.java.template	Wed Dec 20 09:14:52 2017 -0800
@@ -36,6 +36,8 @@
 import java.util.stream.$Streamtype$Stream;
 #end[streamableType]
 
+import jdk.internal.util.ArraysSupport;
+
 /**
  * $A$ $type$ buffer.
  *
@@ -287,6 +289,11 @@
         this(mark, pos, lim, cap, null, 0);
     }
 
+    @Override
+    Object base() {
+        return hb;
+    }
+
 #if[byte]
 
     /**
@@ -1297,19 +1304,9 @@
         $Type$Buffer that = ($Type$Buffer)ob;
         if (this.remaining() != that.remaining())
             return false;
-        int p = this.position();
-        for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--)
-            if (!equals(this.get(i), that.get(j)))
-                return false;
-        return true;
-    }
-
-    private static boolean equals($type$ x, $type$ y) {
-#if[floatingPointType]
-        return (x == y) || ($Fulltype$.isNaN(x) && $Fulltype$.isNaN(y));
-#else[floatingPointType]
-        return x == y;
-#end[floatingPointType]
+        return BufferMismatch.mismatch(this, this.position(),
+                                       that, that.position(),
+                                       this.remaining()) < 0;
     }
 
     /**
@@ -1336,11 +1333,11 @@
      *          is less than, equal to, or greater than the given buffer
      */
     public int compareTo($Type$Buffer that) {
-        int n = this.position() + Math.min(this.remaining(), that.remaining());
-        for (int i = this.position(), j = that.position(); i < n; i++, j++) {
-            int cmp = compare(this.get(i), that.get(j));
-            if (cmp != 0)
-                return cmp;
+        int i = BufferMismatch.mismatch(this, this.position(),
+                                        that, that.position(),
+                                        Math.min(this.remaining(), that.remaining()));
+        if (i >= 0) {
+            return compare(this.get(this.position() + i), that.get(this.position() + i));
         }
         return this.remaining() - that.remaining();
     }
@@ -1571,6 +1568,12 @@
 
 #end[!byte]
 
+#if[char]
+    // The order or null if the buffer does not cover a memory region,
+    // such as StringCharBuffer
+    abstract ByteOrder charRegionOrder();
+#end[char]
+
 #if[byte]
 
     boolean bigEndian                                   // package-private