[llvm-commits] [patch] Switch LTO to use MC

[Rafael Avila de Espindola]

>> Doing llvm-link of all the IL files is about 3m if I remember
>> correctly.
>
> Wow.  Out of curiosity, is much of that time spent in type resolution
> stuff?  I expect that to disappear when the (post 2.9) type system
> rewrite happens.  I think we can make the "loading + linking" process
> much faster :)

Not sure. I did noticed that it looks like the merge is done two modules 
at a time with no state saved. It might be possible to save some time in 
there.

Btw, I have seen the 3.0 planned type changes mentioned some times, but 
I don't know what they are in detail. Is there a doc somewhere?

> Aha, very nice.  That should be possible by just reusing a
> memorybuffer or something.

Yes, I just need a way to represent MemoryBuffers that are not NULL 
terminated :-)

> Thanks for pushing LTO compile times forward!

My pleasure! It is a really cool optimisation in itself, but what I am 
really excited is looking for optimisation opportunities in the large 
.bc files it produces. Trying to avoid startup relocations would be a 
big win for Firefox for example.

> -Chris
>

Cheers,
Rafael