The LRA branch has been merged into GCC trunk as a new feature of GCC 4.8
GCC 4.8 already has many features ready
for this next open-source compiler release due out in 2013, but now it has one more: LRA. The Local Register Allocator branch of GCC was merged to trunk, per this mailing list post
from the branch's creator, Vladimir Makarov of Red Hat.
The Local Register Allocator for GCC is another approach to reload-replacement with trying to succeed a bloated and complicated part of the compiler, lots of macro hooks being unnecessary, and room for improvement with the generated code performance.
For those compiler enthusiasts wishing to learn more about GCC's Local Register Allocator, which has been in-development for more than one year as a big project, see the Red Hat slides
for the low-level juicy details.