diff --git a/core/java/com/android/internal/util/BitwiseInputStream.java b/core/java/com/android/internal/util/BitwiseInputStream.java
index 5da3bc64fc919..4757919f23f59 100644
--- a/core/java/com/android/internal/util/BitwiseInputStream.java
+++ b/core/java/com/android/internal/util/BitwiseInputStream.java
@@ -51,7 +51,7 @@ public class BitwiseInputStream {
      */
     public BitwiseInputStream(byte buf[]) {
         mBuf = buf;
-        mEnd = buf.length * 8;
+        mEnd = buf.length << 3;
         mPos = 0;
     }
 
@@ -70,13 +70,13 @@ public class BitwiseInputStream {
      * @return byte of read data (possibly partially filled, from lsb)
      */
     public byte read(int bits) throws AccessException {
-        int index = mPos / 8;
-        int offset = 16 - (mPos % 8) - bits;
+        int index = mPos >>> 3;
+        int offset = 16 - (mPos & 0x07) - bits;  // &7==%8
         if ((bits < 0) || (bits > 8) || ((mPos + bits) > mEnd)) {
             throw new AccessException("illegal read " +
                 "(pos " + mPos + ", end " + mEnd + ", bits " + bits + ")");
         }
-        int data = (mBuf[index] & 0xFF) << 8;
+        int data = (mBuf[index] & 0x00FF) << 8;
         if (offset < 8) data |= (mBuf[index + 1] & 0xFF);
         data >>>= offset;
         data &= (-1 >>> (32 - bits));
@@ -92,10 +92,10 @@ public class BitwiseInputStream {
      * @return newly allocated byte array of read data
      */
     public byte[] readByteArray(int bits) throws AccessException {
-        int bytes = (bits / 8) + ((bits % 8) > 0 ? 1 : 0);
+        int bytes = (bits >>> 3) + ((bits & 0x07) > 0 ? 1 : 0);  // &7==%8
         byte[] arr = new byte[bytes];
         for (int i = 0; i < bytes; i++) {
-            int increment = Math.min(8, bits - (i * 8));
+            int increment = Math.min(8, bits - (i << 3));
             arr[i] = (byte)(read(increment) << (8 - increment));
         }
         return arr;
diff --git a/core/java/com/android/internal/util/BitwiseOutputStream.java b/core/java/com/android/internal/util/BitwiseOutputStream.java
index 5941bf3203e99..17f5c7ca7f3fa 100644
--- a/core/java/com/android/internal/util/BitwiseOutputStream.java
+++ b/core/java/com/android/internal/util/BitwiseOutputStream.java
@@ -51,7 +51,7 @@ public class BitwiseOutputStream {
      */
     public BitwiseOutputStream(int startingLength) {
         mBuf = new byte[startingLength];
-        mEnd = startingLength * 8;
+        mEnd = startingLength << 3;
         mPos = 0;
     }
 
@@ -61,7 +61,7 @@ public class BitwiseOutputStream {
      * @return newly allocated byte array
      */
     public byte[] toByteArray() {
-        int len = (mPos / 8) + ((mPos % 8) > 0 ? 1 : 0);
+        int len = (mPos >>> 3) + ((mPos & 0x07) > 0 ? 1 : 0);  // &7==%8
         byte[] newBuf = new byte[len];
         System.arraycopy(mBuf, 0, newBuf, 0, len);
         return newBuf;
@@ -74,8 +74,8 @@ public class BitwiseOutputStream {
      */
     private void possExpand(int bits) {
         if ((mPos + bits) < mEnd) return;
-        byte[] newBuf = new byte[((mPos + bits) * 2) / 8];
-        System.arraycopy(mBuf, 0, newBuf, 0, mEnd / 8);
+        byte[] newBuf = new byte[(mPos + bits) >>> 2];
+        System.arraycopy(mBuf, 0, newBuf, 0, mEnd >>> 3);
         mBuf = newBuf;
     }
 
@@ -91,12 +91,12 @@ public class BitwiseOutputStream {
         }
         possExpand(bits);
         data &= (-1 >>> (32 - bits));
-        int index = mPos / 8;
-        int offset = 16 - (mPos % 8) - bits;
+        int index = mPos >>> 3;
+        int offset = 16 - (mPos & 0x07) - bits;  // &7==%8
         data <<= offset;
         mPos += bits;
         mBuf[index] |= (data >>> 8);
-        if (offset < 8) mBuf[index + 1] |= (data & 0xFF);
+        if (offset < 8) mBuf[index + 1] |= (data & 0x00FF);
     }
 
     /**
@@ -107,7 +107,7 @@ public class BitwiseOutputStream {
      */
     public void writeByteArray(int bits, byte[] arr) throws AccessException {
         for (int i = 0; i < arr.length; i++) {
-            int increment = Math.min(8, bits - (i * 8));
+            int increment = Math.min(8, bits - (i << 3));
             if (increment > 0) {
                 write(increment, (byte)(arr[i] >>> (8 - increment)));
             }
diff --git a/tests/AndroidTests/src/com/android/unit_tests/BitwiseStreamsTest.java b/tests/AndroidTests/src/com/android/unit_tests/BitwiseStreamsTest.java
index 2c9075c0265c3..a93524776d216 100644
--- a/tests/AndroidTests/src/com/android/unit_tests/BitwiseStreamsTest.java
+++ b/tests/AndroidTests/src/com/android/unit_tests/BitwiseStreamsTest.java
@@ -23,6 +23,8 @@ import com.android.internal.util.HexDump;
 import android.test.AndroidTestCase;
 import android.test.suitebuilder.annotation.SmallTest;
 
+import android.util.Log;
+
 public class BitwiseStreamsTest extends AndroidTestCase {
     private final static String LOG_TAG = "BitwiseStreamsTest";
 
@@ -85,4 +87,27 @@ public class BitwiseStreamsTest extends AndroidTestCase {
         for (int i = 0; i < inBufDup.length; i++) inBufDup[i] = inStream.read(8);
         assertEquals(HexDump.toHexString(inBuf), HexDump.toHexString(inBufDup));
     }
+
+    @SmallTest
+    public void testFive() throws Exception {
+        int num_runs = 10;
+        long start = android.os.SystemClock.elapsedRealtime();
+        for (int run = 0; run < num_runs; run++) {
+            int offset = run % 8;
+            byte[] inBuf = HexDump.hexStringToByteArray("00031040900112488ea794e0");
+            BitwiseOutputStream outStream = new BitwiseOutputStream(30);
+            outStream.skip(offset);
+            for (int i = 0; i < inBuf.length; i++) {
+                outStream.write(5, inBuf[i] >>> 3);
+                outStream.write(3, inBuf[i] & 0x07);
+            }
+            BitwiseInputStream inStream = new BitwiseInputStream(outStream.toByteArray());
+            inStream.skip(offset);
+            byte[] inBufDup = new byte[inBuf.length];
+            for (int i = 0; i < inBufDup.length; i++) inBufDup[i] = inStream.read(8);
+            assertEquals(HexDump.toHexString(inBuf), HexDump.toHexString(inBufDup));
+        }
+        long end = android.os.SystemClock.elapsedRealtime();
+        Log.d(LOG_TAG, "repeated encode-decode took " + (end - start) + " ms");
+    }
 }