[Mesa-dev] [PATCH] i965: do not release GLSL IR for SSO programs

[Tapani Pälli]

On 10/29/2016 03:29 AM, Kenneth Graunke wrote:
> On Friday, October 28, 2016 10:39:01 AM PDT Tapani Pälli wrote:
>> On 10/28/2016 05:15 AM, Timothy Arceri wrote:
>>> On Thu, 2016-10-27 at 18:51 -0700, Kenneth Graunke wrote:
>>>> On Thursday, October 27, 2016 9:03:12 PM PDT Timothy Arceri wrote:
>>>>> On Thu, 2016-10-27 at 12:37 +1100, Timothy Arceri wrote:
>>>>>> Agreed but as far as I can tell we shouldn't even need
>>>>>> gl_linked_shader
>>>>>> after glLinkProgram.
>>>>>>
>>>>>> We should probably just free it after linking. Everything we want
>>>>>> *should* have been copied to gl_program, however in practice it
>>>>>> seems
>>>>>> there are some things we still get from gl_linked_shader
>>>>>> like NumImages, but with the changes I landed recently we could
>>>>>> just
>>>>>> be getting this from the new shader_info struct.
>>>>> I've started work on this:
>>>>>
>>>>> https://patchwork.freedesktop.org/series/14471/
>>>>>
>>>>> But I'm not sure I have is in me to do another big refactor right
>>>>> now.
>>>> Is there a reasonable short-term fix?  This regression is present on
>>>> the 13.0 branch and we really ought to fix it before Emil cuts the
>>>> 13.0
>>>> final release.  But it'd be nice if we could keep some freeing of
>>>> IR...
>>> I was thinking about this yesterday and the only options I see are
>>> using this patch for the 13.0 branch or leaving it broken.
>>>
>>> The scenario for this bug is highly unlikey you need to be in compat
>>> profile, and relinking a SSO program that has had its shaders
>>> detached.
>>
>> Yeah, this is quite exotic, I'd vote for this patch now and we can make
>> things better from there. I hope Serious Sam 3 (which is the only
>> program I know using SSO) does core profile. Eero, have we recently run
>> this game if it still works?
>
> Actually, lots of games use SSO...
>
> - Bioshock Infinite
> - Chivalry: Medieval Warfare
> - DiRT Showdown
> - Dota 2
> - Saints Row: The Third
> - Serious Sam 3
> - The Talos Principle
> - Tomb Raider
>
> and probably a bunch of others.  As far as I know they all use core
> profile, though.
>

OK, good to know there's some more games.

So .. how about the proposal of using this patch?

IMHO I would prefer instead erroring out if there are no shaders but 
compatibility profile allows such empty programs to link. I'd like to 
understand this case better. I don't understand what is expected result 
when there is no VS or FS and then we use the shader to draw something? 
What kind of output should be generated?

// Tapani