[Mesa-dev] [PATCH 1/3] gallium: Add PIPE_COMPUTE_CAP_MAX_CONSTANT_BUFFER_SIZE

[Marek Olšák]

Sorry, GL 3.1 actually only requires 1024 vec4s. The UBO extension
spec contains a mistake.

Marek

On Thu, Jul 24, 2014 at 4:55 PM, Marek Olšák <maraeo at gmail.com> wrote:
> OpenGL 3.1 requires 4096 vec4s (65536 bytes) per constant buffer and
> the hardware supports 16 constant buffers. I'm not sure what the
> "constant registers" are, but they cannot have anything to do with the
> constant buffer limit, because otherwise we wouldn't be able to meet
> the requirement for uniform buffer objects.
>
> Marek
>
> On Thu, Jul 24, 2014 at 4:05 PM, Jan Vesely <jan.vesely at rutgers.edu> wrote:
>> On Thu, 2014-07-24 at 06:35 -0700, Tom Stellard wrote:
>>> On Thu, Jul 24, 2014 at 01:09:49PM +0200, Marek Olšák wrote:
>>> > Isn't this redundant with get_shader_param(PIPE_SHADER_COMPUTE,
>>> > PIPE_SHADER_CAP_MAX_CONSTS) * 16?
>>> >
>>>
>>> This is what clover was using, but I was confused about what the value
>>> was supposed to represent.  Now, I think I understand (number of 4 x 32-bit
>>> constants).  I can use this instead.
>>
>> Is the value for r600 hw misreported then? The manuals for R600/EG/NI
>> say there are 512 such registers. Yet the driver reports 4096.
>> See the attached patch.
>>
>> Jan
>>
>>>
>>> -Tom
>>> > Marek
>>> >
>>> > On Thu, Jul 24, 2014 at 3:05 AM, Tom Stellard <thomas.stellard at amd.com> wrote:
>>> > > ---
>>> > >  src/gallium/docs/source/screen.rst   | 2 ++
>>> > >  src/gallium/include/pipe/p_defines.h | 3 ++-
>>> > >  2 files changed, 4 insertions(+), 1 deletion(-)
>>> > >
>>> > > diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
>>> > > index 830a1a5..219c9f9 100644
>>> > > --- a/src/gallium/docs/source/screen.rst
>>> > > +++ b/src/gallium/docs/source/screen.rst
>>> > > @@ -334,6 +334,8 @@ pipe_screen::get_compute_param.
>>> > >    Value type: ``uint32_t``
>>> > >  * ``PIPE_COMPUTE_CAP_IMAGES_SUPPORTED``: Whether images are supported
>>> > >    non-zero means yes, zero means no. Value type: ``uint32_t``
>>> > > +* ``PIPE_COMPUTE_CAP_MAX_CONSTANT_BUFFER_SIZE``: The maximum size in bytes
>>> > > +  of a constant buffer.  Value type: ``uint64_t``
>>> > >
>>> > >  .. _pipe_bind:
>>> > >
>>> > > diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
>>> > > index 43bb1f5..78709b9 100644
>>> > > --- a/src/gallium/include/pipe/p_defines.h
>>> > > +++ b/src/gallium/include/pipe/p_defines.h
>>> > > @@ -651,7 +651,8 @@ enum pipe_compute_cap
>>> > >     PIPE_COMPUTE_CAP_MAX_MEM_ALLOC_SIZE,
>>> > >     PIPE_COMPUTE_CAP_MAX_CLOCK_FREQUENCY,
>>> > >     PIPE_COMPUTE_CAP_MAX_COMPUTE_UNITS,
>>> > > -   PIPE_COMPUTE_CAP_IMAGES_SUPPORTED
>>> > > +   PIPE_COMPUTE_CAP_IMAGES_SUPPORTED,
>>> > > +   PIPE_COMPUTE_CAP_MAX_CONSTANT_BUFFER_SIZE
>>> > >  };
>>> > >
>>> > >  /**
>>> > > --
>>> > > 1.8.1.5
>>> > >
>>> > > _______________________________________________
>>> > > 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
>>> _______________________________________________
>>> mesa-dev mailing list
>>> mesa-dev at lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>> --
>> Jan Vesely <jan.vesely at rutgers.edu>