On Thu, Jun 10, 2010 at 02:03:03PM -0600, Jeff Law wrote: > That adds quite a bit of complication to the compiler though -- > getting the instruction lengths right (and thus proper packing & > alignment) can be extremely difficult. I did some experiments with > this on a target with *fixed* instruction lengths a while back and > even though the port tried hard to get lengths right, it would > routinely miss something. Ultimately I decided that it forcing the > compiler to know instruction lengths with a very high degree of > accuracy wasn't a sane thing to do.
FWIW, my opinion (and I think Jakub has expressed a similar opinion and/or tool in the past) is that there is a sane way to do this: put assertions in the assembler output and have the assembler validate them. On the other hand, I'm not going to argue that it's a lot of work. -- Daniel Jacobowitz CodeSourcery
