Re: First cut on outputing gimple for LTO using DWARF3. Discussion invited!!!!

[Kenneth Zadeck <zadeck at naturalbridge dot com>]

Chris Lattner wrote:
> On Aug 28, 2006, at 6:57 AM, Kenneth Zadeck wrote:
>
>> This posting is a progress report of my task of encoding and decoding
>> the GIMPLE stream into LTO.   Included in this posting is a patch that
>> encodes functions and dumps the result to files.
>
> Interesting email.  One question: how big are the files you're
> generating?  For example, how much space does it take to store the
> body of a function with 100 add operations in it (before gzip'ing
> it)?  What is the size proportional to?  # instructions, # basic
> blocks, what else?
>
> -Chris
The size will be large because the trees are still large.  Encoding
everything in a bootstrap for the three languages was on the order of
60mb.  As you know, size is a well known problem in gcc.  The plan is to
track the changes in gimple and as that gets smaller, this will get
smaller. 

I would like to get the types and perhaps the flags out of the internal
nodes of the trees.  when that gets done, these operations should be small.

I actually do not think that it is productive to spend that much time
measuring this until we first assure ourselves that we are getting all
of the information output correctly.  That 60mb number will change a lot
(both up and down) as we get closer to getting everything tied
together.  Then we can spend more time looking at the pieces and seeing
where we need to do better.