Combine four insns

[Laurynas Biveinis]

2010/8/9 Steven Bosscher <stevenb.gcc@gmail.com>:
> This is interesting. Years ago (7 years?) Zack Weinberg suggested that
> GCC should move RTL back onto obstacks. The overhead should be
> relatively small compared to keeping entire functions-as-trees in
> memory. This is even more true today, now we keep entire translation
> units (and more) in memory as GIMPLE (with SSA). Memory spent on RTL
> is marginal compared to that.
>
> I passes this idea to Laurynas last year ago
> (http://gcc.gnu.org/ml/gcc/2009-08/msg00386.html). I don't know if he
> played with the idea or not.

IMHO it's a very good idea and now it is on the top of my GCC TODO
list. Don't know when I'll get around doing this (busy in the final
months of the grad school), or if somebody won't beat me to it.
Anyway, I also made a note of this patch :)

-- 
Laurynas