Re: [Qemu-devel] [RFC PATCH v2] coccinelle: add a script to optimize tcg op using tcg_gen_extract()

[Markus Armbruster]

Philippe Mathieu-Daudé <address@hidden> writes:

> Hi Markus,
>
> On 05/11/2017 06:03 AM, Markus Armbruster wrote:
>> Philippe Mathieu-Daudé <address@hidden> writes:
>>
>>> Ok I just understood Richard explanation, so this patch is WRONG and I
>>> need to get some real rest :(
>>
>> Ha!  Get some sleep; we'll still be around in the morning ;)
>>
>>> On 05/10/2017 08:52 PM, Philippe Mathieu-Daudé wrote:
>>>> Apply this script using:
>>>>
>>>> $ docker run -v `pwd`:`pwd` -w `pwd` petersenna/coccinelle \
>>>>     --sp-file scripts/coccinelle/tcg_gen_extract.cocci \
>>>>     --macro-file scripts/cocci-macro-file.h \
>>>>     --dir target \
>>>>     --in-place
>>>>
>>>> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
>>>> ---
>>>>
>>>> This is a new version of the coccinelle script addressing Richard comments 
>>>> and
>>>> trying to do it correctly. Also changed license to GPLv2+.
>>>>
>>>> The first rule matches, it calls a python2 script that basically checks the
>>>> target_ulong is not overflowed: (msk << ofs) >> sizeof(target_ulong) == 0
>>>
>>> WRONG
>> [...]
>>
>> Is this script likely to be rerun in the future?  If yes, keeping it in
>> scripts/coccinelle/ is a good idea.  If no, I recommend to store it in
>> the commit message instead.
>
> It is unlikely to be rerun in the future, at least for this specific
> pattern. But it can be easily adapted for another TCG optimization.
>
> I could not find much documentation about how to do a such script
> using Python, except on a thread [1]. If it is documented enough I
> think it is worth to keep it.
>
> About putting it in each commit message, it is now 3 times bigger than
> the patch it generates!

Consider putting it into the first commit message, and have the others
reference back.