[LLVMdev] New 8bit micro controller back-end

[David Greene]

On Monday 23 November 2009 09:01, Anton Korobeynikov wrote:
> Hello
>
> > It is a RISC with around 60 instructions like a 80c51 instruction set
> > (without mul/div) and with Direct or indirect memory acces.
>
> My estimate is something like a man-week for a person, who knows what to do
> :)

That's pretty optimistic, even for someone who knows what to do.

The learning curve for TableGen is quite steep.  I would budget at least a
year for everything; learning TableGen, writing patterns, custom lowering,
testing, etc.

And that's for a relatively simple, orthogonal ISA.

Of course this happens iteratively.  You learn a little TableGen (mostly by
looking at existing backends and asking lots of questions), write a few 
patterns, learn a little more and so on.

                                -Dave