writing custom machine descriptions

[dewar@gnat.com]

<<We have designed our own processor. In order to
generate assembly instructions for the desired
architecture will I have to add machine description
files (as has been done in gcc's config directory)?
Or will I also have to modify the gcc backend as well?
>>

If the architecture is conventional enough (enough is hard to define
precisely), then only a new machine description file is required. In
the past, new architectures have sometimes required new feaures in
the gcc backend, especially to make sure that optimal code is generated,
but that is less true as time goes on, and unless your architecture is
weird, it is likely you can get a quite decent compiler by simply providing
a new machine description file.