As reported in a forum, the microbenchmark below slips markedly in performance from 5.0 to 6.0, using the server compiler.

The slip most noticeable in x86 architectures, but can be observed to a lesser degree on sparc.

class eclipsetest {
  static final byte[] byteBuf = new byte[10000];
  static final char[] buf = new char[10000];

  public static void main( String[] args ) throws Exception {
    for ( int i = 0; i < 1000; i++ ) {
      redo_work(1000, 100, 100);
    }
    System.out.println("Warmup done.");

    for ( int x = 0; x < 4; x++ ) {
      long start = System.currentTimeMillis();

      redo_work(1000, 100, 100000);

      long end = System.currentTimeMillis();
      System.out.println( "total time: " + (end - start) );
    }
  }

  public static int redo_work(int byteIndex, int offset, int redo) {
    for ( int i = 0; i < redo; i++ ) {
      work(byteIndex, offset);
    }
    return 0;
  }

  public static int work(int byteIndex, int offset) {
    if ( (byteIndex - offset) < 0 )
      throw new RuntimeException();

    for ( ; byteIndex < byteBuf.length; byteIndex++ ) {
      if ( byteBuf[byteIndex] < 6 ) {
if ( byteBuf[byteIndex] == 5 ) {
buf[byteIndex - offset] = '\n';
}
      }
      buf[byteIndex - offset] = (char)byteBuf[byteIndex];
    }

    return 0;
  }
}