Re: [RFC] WHOPR - A whole program optimizer framework for GCC

[Harvey Harrison <harvey dot harrison at gmail dot com>]

On Wed, 2007-12-12 at 15:06 -0500, Diego Novillo wrote:
> Over the last few weeks we (Google) have been discussing ideas on how to
> leverage the LTO work to implement a whole program optimizer that is
> both fast and scalable.
> 
> While we do not have everything thought out in detail, we think we have
> enough to start doing some implementation work.  I tried attaching the 
> document, but the mailing list rejected it.  I've uploaded it to
> http://airs.com/dnovillo/pub/whopr.pdf
> 
> The most important goal we have with this project is the ability to
> handle Really Large programs (millions of functions, millions of
> call-graph edges) with some grace. So, the design tries pretty hard to
> make use of concurrency and clusters to partition the work.
> 
> At this point we are interested in getting feedback on the general idea.
> There is some refactoring that will be needed inside the call-graph
> manager and some aspects of the design may not even need a lot of
> changes in GCC. But in general, it will require very efficient IR streaming.
> 
> In terms of implementation, we will likely use the LTO branch as a
> basis. Many of the features we will need are already being implemented
> in the branch, so we will keep helping with that implementation.
> 

I'm curious how this interacts/complements  with any efforts to
using the LLVM IR in LTO.

Any pointers to where that discussion ended up?

Harvey