Merging Graphite to trunk

[Albert Cohen]

Sebastian Pop wrote:
> (...)
>> do we really have to merge this?  Why does it have to be in toplev.c
>> and using global variables?
>>
> 
> What do you think to not commit all this stuff at all, and leave all
> this stuff in the Graphite branch for the moment?
> 
> Frankly, I don't think that the read/write interface should be exposed
> to programmers.  I used these options once to test some loop
> transforms by hand: it was useful and quite simple to use, but I never
> used these flags after that.
> 
> The read/write flags may be useful to the http://ctuning.org folks,
> but they could come up with a better way to interact with Graphite.

Indeed. These flags should probably be limited to the branch.

They may be used for ctuning as a quick an dirty hack, but not in the 
long term. They may also enable interesting interactions between 
Graphite and external research prototypes we are developping, e.g., at 
INRIA. It could also provide interesting "preview" performance numbers 
to motivate more people to invest into Graphite and GCC. But when PCP 
becomes available, it will deprecate those flags completely.

Albert