* Linaro GCC
Discovered that part of my conditional execution problems were caused by some over-zealous peephole optimizations adding CC register clobbers to arithmetic operations in order to take advantage of the 16-bit encoding. This is a problem because they can't be converted to conditional execution so freely because overwriting the CC register prevents any further conditional execution (and forces a 32-bit encoding unnecessarily). I wrote a patch to help ifcvt unpick all this and DTRT, and posted it upstream. It turns out that Benrd (I think) already reimplemented the peephole optimization in the reorg pass, so all that is really needed is to delete the now obsolete peepholes. Richard E has approved the revised patch. Unfortunately I've now discovered that that exposed a bug in the machine description, so that'll have to be fixed also.
Tried to update the gcc-linaro/4.7 branch, but found the build broken. In fact, Matthias had already reported it to Bugzilla. I did a binary search, identified the problem commit, posted the info to bugzilla, and pushed a merge request for the last working commit for testing. This tested ok, so I've merged it to the Linaro 4.7 trunk.
Brought the Linaro GCC patch tracker up to date to aid identification of patches we will need to forward port to 4.7. The remaining 'red' patches are either not committed upstream, or I wasn't sure.
Attempted to benchmark the 64-bit shift improvements, but the target board (ursa1) has developed an I/O error.
* Other
Joe Seymour and I went to HP Bristol to attend one of their science lectures. Professor Jim Al-Khalili gave a talk about the recent "faster-than-light" neutrinos experiments, and explained why it can't possibly be true. http://www.jimal-khalili.com/blog/faster-than-the-speed-of-light.html