Among many other differences, the first and most visible one is the resulting image:
I have a uchar4 buffer in which I hold an image (rgbxrgbx...).
In the 2.1 it looked ok. All I did was to install the new ccc (10.8) and sdk, and the colors are all wrong: rhe red chanel (s) is about half image lower than the green and blue (s and s), in small images (320*240) the image looks interleaved (one row of pixels ok, the other translated a bit), in medium images (640*480) only the green and blue look interleaved.
Just for testing, Image[index]=as_uchar4(index); gives interleaved lines like mentioned above. In 2.1 it showed many gradient squares from red to green and black.
and Image[index].xy=as_uchar2(ushort); crashes the compiler.