exhibit JIT compile bug in jdk 1.6.0_21

gistfile1.java

import java.lang.reflect.Field;
import java.util.Arrays;

import sun.misc.Unsafe;

public class Inline
{
    private static final int BASE_LENGTH = 7;
    private static final int[] LENGTHS = new int[] {1, 2, 3, 4, 5, 6};
    private static final Unsafe UNSAFE;
    private static final long ARRAY_BASE_OFFSET;

    static
    {
        try
        {
            Field f = Unsafe.class.getDeclaredField("theUnsafe");
            f.setAccessible(true);
            UNSAFE = (Unsafe) f.get(null);
            ARRAY_BASE_OFFSET = UNSAFE.arrayBaseOffset(byte[].class);
        }
        catch (Exception e)
        {
            throw new AssertionError();
        }
    }

    public static void main(String[] args)
    {
        final Inline inline = new Inline();
        final byte[] targetBuffer = new byte[64];
        final byte[] sourceBuffer = new byte[64];
        Arrays.fill(sourceBuffer, (byte) 7);

        for(int i = 0; i < 500000; i++)
        {
            writeInt(targetBuffer, 0, i % 15);
        }

        System.out.println(readInt(targetBuffer, 0));

        for(int i = 0; i < 500000; i++)
        {
            if(!inline.createArray(targetBuffer, sourceBuffer))
            {
                System.err.println("Failed");
                return;
            }
        }
    }

    private boolean createArray(final byte[] buffer, final byte[] sourceBuffer)
    {
        try
        {
            final int length = getLength();
            writeInt(buffer, 0, length);

            System.arraycopy(sourceBuffer, 0, buffer, 0, length);
        }
        catch(RuntimeException e)
        {
            e.printStackTrace();
            return false;
        }

        return true;
    }

    private int getLength()
    {
        return BASE_LENGTH + LENGTHS[((int)System.currentTimeMillis()) % LENGTHS.length];
    }

    private static void writeInt(byte[] buffer, int offset, int i)
    {
        UNSAFE.putInt(buffer, ARRAY_BASE_OFFSET + offset, toBigEndian(i));
    }

    private static int readInt(byte[] buffer, int offset)
    {
        return toBigEndian(UNSAFE.getInt(buffer, ARRAY_BASE_OFFSET + offset));
    }

    private static int toBigEndian(int i)
    {
        return Integer.reverseBytes(i);
    }
}