msp430 port

[DJ Delorie]

> > The first doesn't have a clobber, though...
> 
> Hmm.  Missed that.  So the only reason you'd care to include the bic
> in the regular and pattern is if it were a smaller encoding than the
> regular r/0/i alternative.

It is, but the separate pattern picks that out just fine.

> You need to implement the "return" pattern as well as "simple_return".
> They don't actually have to be different, implementation-wise.  See
> the i386 version, where both named patterns expand to the same insn.

How is this an advantage from just building the return from the epilog
expander?

> It depends on your requirements.  Is it strictly 1, 2, 4 registers?  In
> which case it's easiest to use HI, SI, DImode with one output.

It's an arbitrary number of registers, used only by the epilogue
expander.

> If you only need them post-reload, follow the lead of the s390 port.
> See the "load_multiple" and "store_multiple" expanders, and their
> associated insns.  In this case, everything folds nicely down with
> a match_parallel.

Will do.