Yes, I have encountered the problem before that OS X crashes on incorrect stack alignment even where other platforms tolerate it. Good point about the stall --

Yes, I have encountered the problem before that OS X crashes on incorrect stack alignment even where other platforms tolerate it. Good point about the stall -- I always thought that partial register stall happened at the point that you do the partial write, since the logical contents of the register now depend on its previous contents. I didn't realize that the dependency logic was sophisticated enough to allow the partial read without depending on the entire register's value.