Re: [Qemu-devel] 64-on-32 TCG broken

[Paolo Bonzini]

Il 31/10/2012 13:40, Aurelien Jarno ha scritto:
>>> I just tested with latest qemu-system-x86_64 on 32 bit Linux.
>>>
>>> It also hangs during boot (BIOS), so it looks like this
>>> is not a MinGW only problem.
>>>
>>> Your test with x86_64-linux-user indicates that, too.
>>>
>>> I also get the problem with TCI. Therefore I expect that any
>>> 32 bit TCG target will show it.
>>>
>>
>> It ended up to be a merge issue. The newly added special cases
>> for half-dead operations also need to be changed with the liveness
>> analysis rework.
>>
>> The attached patch fixes the issue on a 32-bit linux host. I haven't
>> tried win32 yet, maybe someone will beat me.
>>
> 
> I have just been able to try, and I confirm it fixes the problem on
> win32.

Thanks!  In general, do not rebase a branch unless you were able to test
the rebase fully.  Use "git merge" instead.  This does not apply to
people without commit access (unless they use pull requests---perhaps we
should use them more), but it is easy for you.

If you hadn't rebased the series, "git bisect" would have pointed out
that the original series worked, and that the merge was the problem.
(Yes, this is less accurate than knowing *which* patch made invalid
assumptions after the rebase.  However, you can always do a temporary
rebase to find that.  A linearized history doesn't say what was the
latest "master" commit on top of which you tested).

Paolo