xf. http://lists.linaro.org/pipermail/linaro-toolchain/2010-August/000069.html
It is not upstreamable due to copyright issues, but we have a policy that we can keep such patches, if we wish.
I wrote this patch. If I am the copyright issue, then there is no issue.
I have a copyright assignment for all my GCC work to the FSF. That assignment also covers the patch in the e-mail stored at http://gcc.gnu.org/ml/gcc-patches/2008-12/msg00199.html. I consider copyright to all my patches assigned to the FSF if I have submitted the patches to gcc-patches@gcc.gnu.org, or attached them to a Problem Report in GCC bugzilla, or both.
The only reason why this patch for GIMPLE PRE is not in the FSF GCC already, is that I just never cared enough to pursue it. GCC is just a hobby for me, and experimenting with ideas is fun. Doing all the required testing for inclusion in the FSF GCC is not fun and it costs time that I usually can't find. I am just too busy with other things to clear off this and other pending patches/ideas from my TODO list :-)
If you wish to submit this patch for the FSF GCC, please feel free to do so. In fact, I'd encourage you to do so. Likewise for my patch for e.g. http://gcc.gnu.org/PR20070, and for the GIMPLE hoisting pass.
Ciao! Steven