[Mesa-dev] [PATCH v5 01/70] mesa: set MAX_SHADER_STORAGE_BUFFERS to 15.

[Iago Toral]

On Thu, 2015-09-10 at 15:17 -0400, Ilia Mirkin wrote:
> On Thu, Sep 10, 2015 at 2:52 PM, Ian Romanick <idr at freedesktop.org> wrote:
> > On 09/10/2015 10:45 AM, Ilia Mirkin wrote:
> >> On Thu, Sep 10, 2015 at 9:35 AM, Iago Toral Quiroga <itoral at igalia.com> wrote:
> >>> From: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
> >>>
> >>> This patch sets the same value used for uniform buffers.
> >>>
> >>> Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
> >>> ---
> >>>  src/mesa/main/config.h | 2 +-
> >>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/src/mesa/main/config.h b/src/mesa/main/config.h
> >>> index b35031d..69acd7d 100644
> >>> --- a/src/mesa/main/config.h
> >>> +++ b/src/mesa/main/config.h
> >>> @@ -171,7 +171,7 @@
> >>>  #define MAX_PROGRAM_LOCAL_PARAMS       4096
> >>>  #define MAX_UNIFORMS                   4096
> >>>  #define MAX_UNIFORM_BUFFERS            15 /* + 1 default uniform buffer */
> >>> -#define MAX_SHADER_STORAGE_BUFFERS     7  /* + 1 default shader storage buffer */
> >>> +#define MAX_SHADER_STORAGE_BUFFERS     15  /* + 1 default shader storage buffer */
> >>
> >> Is there such a thing as a default shader storage buffer? I would have
> >> assumed not, but haven't read the spec.
> >
> > Technically no, but I think (and I'm sure Ken will correct me) i965 uses
> > one for register spilling.  Or is "scratch space" a different sort of thing?
> 
> Sure, but that's a driver-specific thing. The MAX_UNIFORM_BUFFERS
> thing is in reference to the number of uniform buffers in the GL.
> MAX_SHADER_STORAGE_BUFFERS seems like it should be the same thing. Why
> not make it 16? Or perhaps leave it at 15 and remove the comment?

Right, this is used to define the maximum number of binding points
available per shader stage. There is no such thing as a default shader
storage buffer that is different from the others, I think that comment
is just a copy&paste mistake. We can remove the comment and leave this
at 15, or round it up to 16 as you suggest. I'd go with the latter.

Iago

> With uniform buffers, there's a "default" uniform buffer, and then
> there are actual user ones.



> >
> >>>  /* 6 is for vertex, hull, domain, geometry, fragment, and compute shader. */
> >>>  #define MAX_COMBINED_UNIFORM_BUFFERS   (MAX_UNIFORM_BUFFERS * 6)
> >>>  #define MAX_COMBINED_SHADER_STORAGE_BUFFERS   (MAX_SHADER_STORAGE_BUFFERS * 6)
> >>> --
> >>> 1.9.1
> >>>
> >>> _______________________________________________
> >>> mesa-dev mailing list
> >>> mesa-dev at lists.freedesktop.org
> >>> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> >> _______________________________________________
> >> mesa-dev mailing list
> >> mesa-dev at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> >
>