I recently had a BUG_ON() go off spuriously on a gcc 4.0 compiled kernel.
It turns out gcc-4.0 was removing a sign extension while earlier gcc
versions would not.  Thinking this to be a compiler bug, I submitted a
report:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23422

It turns out we need to cast the input in order to tell gcc to sign extend
it.

Thanks to Andrew Pinski for his help on this bug.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This patch eliminates all kernel BUGs, trims about 35k off the typical
kernel, and makes the system slightly faster.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!