--- a/langtools/src/share/classes/com/sun/tools/javac/util/Bits.java	Thu Jan 23 14:09:29 2014 +0100
+++ b/langtools/src/share/classes/com/sun/tools/javac/util/Bits.java	Fri Jan 24 09:39:51 2014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -345,25 +345,4 @@
         }
     }
 
-    /** Test Bits.nextBit(int). */
-    public static void main(String[] args) {
-        java.util.Random r = new java.util.Random();
-        Bits bits = new Bits();
-        for (int i=0; i<125; i++) {
-            int k;
-            do {
-                k = r.nextInt(250);
-            } while (bits.isMember(k));
-            System.out.println("adding " + k);
-            bits.incl(k);
-        }
-        int count = 0;
-        for (int i = bits.nextBit(0); i >= 0; i = bits.nextBit(i+1)) {
-            System.out.println("found " + i);
-            count ++;
-        }
-        if (count != 125) {
-            throw new Error();
-        }
-    }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/util/BitsTest.java	Fri Jan 24 09:39:51 2014 +0100
@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8028267
+ * @summary Unit tests for the com.sun.tools.javac.util.Bits class.
+ * @run main BitsTest
+ */
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+import com.sun.tools.javac.util.Bits;
+
+public class BitsTest {
+
+    final static int[] samples = { 0, 1, 7, 16, 19, 31, 32, 33, 63, 64 };
+    final static int LENGTH = samples[samples.length - 1] + 50;
+
+    public static void main(String... args) throws Exception {
+
+        testIncl();
+        testInclRange();
+        testDup();
+        testClear();
+        testExcl();
+        testExcludeFrom();
+        testBinOps();
+        testNextBit();
+
+    }
+
+
+    // Test Bits.incl
+    static void testIncl() {
+        for (int a : samples) {
+            for (int b : samples) {
+                Bits bits = new Bits();
+                bits.incl(a);
+                if (a != b)
+                    bits.incl(b);
+                for (int i = 0; i < LENGTH; i++)
+                    assert bits.isMember(i) == (i == a || i == b);
+            }
+        }
+    }
+
+
+    // Test Bits.excl
+    static void testExcl() {
+        for (int a : samples) {
+            for (int b : samples) {
+                Bits bits = new Bits();
+                bits.inclRange(0, LENGTH);
+                bits.excl(a);
+                if (a != b)
+                    bits.excl(b);
+                for (int i = 0; i < LENGTH; i++)
+                    assert !bits.isMember(i) == (i == a || i == b);
+            }
+        }
+    }
+
+
+    // Test Bits.inclRange with various ranges.
+    static void testInclRange() {
+        for (int i = 0; i < samples.length; i++) {
+            for (int j = i; j < samples.length; j++)
+                testInclRangeHelper(samples[i], samples[j]);
+        }
+    }
+
+
+    // Tests Bits.inclRange for the given range.
+    static void testInclRangeHelper(int from, int to) {
+        Bits bits = new Bits();
+        bits.inclRange(from, to);
+        for (int i = 0; i < LENGTH; i++)
+            assert bits.isMember(i) == (from <= i && i < to);
+    }
+
+
+    // Test Bits.dup
+    static void testDup() {
+        Bits bits = sampleBits();
+        Bits dupBits = bits.dup();
+        assertEquals(LENGTH, bits, dupBits);
+    }
+
+
+    // Make sure Bits.clear clears all bits.
+    static void testClear() {
+        Bits bits = sampleBits();
+        bits.clear();
+        for (int i = 0; i < LENGTH; i++)
+            assert !bits.isMember(i);
+    }
+
+
+    // Test Bits.excludeFrom
+    static void testExcludeFrom() {
+        Bits bits = sampleBits();
+
+        int half = samples.length / 2;
+        Set<Integer> expected = new HashSet<Integer>();
+        for (int i : Arrays.copyOf(samples, half))
+            expected.add(i);
+
+        bits.excludeFrom(samples[half]);
+
+        for (int i = 0; i < LENGTH; i++)
+            assert bits.isMember(i) == expected.contains(i);
+    }
+
+
+    // Test andSet, orSet, diffSet, xorSet
+    static void testBinOps() {
+        int[] a = { 1630757163, -592623705 };
+        int[] b = { 1062404889, 1969380693 };
+
+        int[] or   = { a[0] | b[0],  a[1] | b[1] };
+        int[] and  = { a[0] & b[0],  a[1] & b[1] };
+        int[] xor  = { a[0] ^ b[0],  a[1] ^ b[1] };
+        int[] diff = { a[0] & ~b[0], a[1] & ~b[1] };
+
+        assertEquals(64, fromInts(a).orSet  (fromInts(b)), fromInts(or));
+        assertEquals(64, fromInts(a).andSet (fromInts(b)), fromInts(and));
+        assertEquals(64, fromInts(a).xorSet (fromInts(b)), fromInts(xor));
+        assertEquals(64, fromInts(a).diffSet(fromInts(b)), fromInts(diff));
+
+    }
+
+
+    // Create a Bits-instance based on bits in 'ints' argument.
+    static Bits fromInts(int[] ints) {
+        Bits bits = new Bits();
+        for (int bit = 0; bit < ints.length * 32; bit++)
+            if ((ints[bit / 32] & (1 << (bit % 32))) != 0)
+                bits.incl(bit);
+        return bits;
+    }
+
+
+    // Asserts that two Bits-instances are equal up to first 'len' bits.
+    static void assertEquals(int len, Bits a, Bits b) {
+        for (int i = 0; i < len; i++)
+            assert a.isMember(i) == b.isMember(i);
+    }
+
+
+    // Test Bits.nextBit
+    static void testNextBit() {
+        Bits bits = sampleBits();
+
+        int index = 0;
+        for (int bit = 0; bit < LENGTH; bit++) {
+
+            int expected;
+
+            // Passed last sample index?
+            if (index < samples.length) {
+                expected = samples[index];
+                if (bit == samples[index])
+                    index++;
+            } else {
+                expected = -1;
+            }
+
+            assert bits.nextBit(bit) == expected;
+        }
+    }
+
+
+    // Convenience method: Generate a Bits-instance based on samples.
+    static Bits sampleBits() {
+        Bits bits = new Bits();
+        for (int i : samples)
+            bits.incl(i);
+        return bits;
+    }
+
+}