[dataflow] partial register handling

[Roman Zippel]

Hi,

On Fri, 11 May 2007, Rask Ingemann Lambertsen wrote:

>    The first one is the insn pattern right below the mulsidi3 expander,
>    right? Please give all insn patterns a name to make searches easier.

It's on the TODO list. :)

>    May I ask why the original insn 7 isn't coded something like
> 
> (set (reg:DI 30) (mult:DI (sign_extend:DI (reg:SI 33))
> 			  (sign_extend:DI (reg:SI 32))))
> 
> instead?

In the long term we want to expose the subreg for better register 
allocation. It would be possible to initially generate this and split it 
later (this would also avoid this problem), but this makes only more 
complicated. So I'm a little hesitant to do this, if we can just generate 
the final form immediately.

bye, Roman