He suggested $24 (t8) another discussed possibility would be $27 (k1) which is already abused by the PS/2 folks for ll/sc emulation. Another possibility would be to reserve such a register only in the n32/n64 ABIs and let o32 stay without __thread and TLS forever. Any feedback welcome.
I vote for $24 (t8). LL/SC emulation is an issue and I believe some of the exception vectors, if not all of them indirectly depend on k1. It would take a lot of work (and testing) to rewrite the exceptions to not utilize k1 and it would probably be a nasty performance hit in many cases. I agree with "Screw o32" and let's move forward.
-Steve
