Conclusion : the computation of the V flag in qemu is correct, and their is
no special case to consider if the C flag is set or not :-)
For tomorrow, the formal proof of the correctness of the whole qemu code
;-)
Thanks for the superb analysis!
Now it's time to check if real hardware works ac
Hello,
As far as the V flag is concerned, I've taken a look at the Sparc V8 reference manual (www.sparc.org/standards/V8.pdf)
We can read at page 170 for the update of the V flag for "addcc" and "addxcc":
Vtheory = (r[rs1]<31> & operand2<31> & !result<31>) | (!r[rs1]<31> & !operand2<31> && resu
As far as the V flag is concerned, mmm, I'm not really sure whether we
should
change something in the sparc code. If we compare to the arm code, we don't
take into account the fact that the carry flag is set before.
We'd probably need some extensive tests and their associated expected
results.
