After a quick code review, it seems to be a bad cut-n-paste between
16-bit and 8-bit UADD/USUB, indeed UADD8/USUB8 tries to set GE bits by
pair instead of one at a time.
Besides, the addition operations (UADD8/UADD16) set GE bits to "NOT
carry" instead of "carry" (probably once again due to a copy of the
substraction code which sets flags to "NOT borrow")
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4900 c046a42c-6fe2-441c-8c8c-71466251a162