[Mesa-dev] Patchwork/mesa-stable question (was: Re: [PATCH v3] r600g: Fix special negative immediate constants when using ABS modifier.)

Nicolai Hähnle nhaehnle at gmail.com
Thu Oct 29 16:11:18 PDT 2015

On 29.10.2015 10:24, Ivan Kalvachev wrote:
> On 10/29/15, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
>> On 29.10.2015 01:52, Ivan Kalvachev wrote:
>>> On 10/26/15, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
>>>> On 25.10.2015 02:00, Ivan Kalvachev wrote:
>>>>> Some constants (like 1.0 and 0.5) could be inlined as immediate inputs
>>>>> without using their literal value. The
>>>>> r600_bytecode_special_constants()
>>>>> function emulates the negative of these constants by using NEG
>>>>> modifier.
>>>>> However some shaders define -1.0 constant and want to use it as 1.0.
>>>>> They do so by using ABS modifier. But r600_bytecode_special_constants()
>>>>> set NEG in addition to ABS. Since NEG modifier have priority over ABS
>>>>> one,
>>>>> we get -|1.0| as result, instead of |1.0|.
>>>>> The patch simply prevents the additional switching of NEG when ABS is
>>>>> set.
>>>> Nice catch. Is there a simple test case (e.g. in piglit) that exposes
>>>> the incorrect behavior?
>>> Not that I know of.
>>> I've located the bug investigating visual problem in Nine.
>>> https://github.com/iXit/Mesa-3D/issues/126
>>> https://github.com/iXit/Mesa-3D/issues/127
>>> I also heard that it fixes artifacts in "Need for Speed: Undercover"
>>> and "Skyrim", once again, when using Nine.
>> I see. I guess it's not too surprising that Nine creates shaders that
>> look a bit different from the Mesa statetracker's.
>> Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>
>> This should probably also go to stable.
>> Do you need somebody to push this for you or can you do it yourself?
>> Cheers,
>> Nicolai
> Yes, please.
> I'm not developer and I cannot push it myself.

I pushed the patch.

I am not familiar with patchwork yet and have a related question: on my 
push, I got the following error message related to patchwork:

remote: E: failed to find patch for rev 

Apparently, patchwork didn't pick up Ivan's v3 patch, perhaps because it 
wasn't inline. Is this something to worry about? Specifically, I believe 
the patch is a candidate for the stable branch, and I added the 
appropriate Cc: in the commit message. Does the message above prevent it 
from being picked up?

Sorry for the noise :/


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