[Mesa-dev] [PATCH 05/13] nir: expose 'C' wrappers for std430 size/alignment

[Rob Clark]

hmm, I haven't tried passing a struct (rather than a pointer to a
struct) as a parameter, but if there were 8/16 bit fields in the
struct it would calculate the size incorrectly.

(otoh the more important question is whether this agrees with how
clover lays out the input buffer, as far as where the n+1'th parameter
starts, which I'm not sure about)

BR,
-R

On Wed, Feb 28, 2018 at 4:47 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> I thought OpenCL used a different set of alignment rules for structs,
> unions, etc.  In particular, I thought it was very close to standard C.  If
> that's true, then std430 is not what you want.
>
> On Wed, Feb 28, 2018 at 1:44 PM, Karol Herbst <kherbst at redhat.com> wrote:
>>
>> it isn't yet. But you would use it in your driver when calculating
>> your memory offsets for kernel arguments. In OpenCL things are aligned
>> in memory by the size of the type and we would use those functions to
>> calculate those.
>>
>> On Wed, Feb 28, 2018 at 10:39 PM, Jason Ekstrand <jason at jlekstrand.net>
>> wrote:
>> > Looking through commit titles, I don't see any obvious place where this
>> > would get used.
>> >
>> > On Wed, Feb 28, 2018 at 11:51 AM, Rob Clark <robdclark at gmail.com> wrote:
>> >>
>> >> Signed-off-by: Rob Clark <robdclark at gmail.com>
>> >> ---
>> >>  src/compiler/nir_types.cpp | 12 ++++++++++++
>> >>  src/compiler/nir_types.h   |  4 ++++
>> >>  2 files changed, 16 insertions(+)
>> >>
>> >> diff --git a/src/compiler/nir_types.cpp b/src/compiler/nir_types.cpp
>> >> index cbdd452dc81..0085a19248a 100644
>> >> --- a/src/compiler/nir_types.cpp
>> >> +++ b/src/compiler/nir_types.cpp
>> >> @@ -117,6 +117,18 @@ glsl_get_aoa_size(const struct glsl_type *type)
>> >>     return type->arrays_of_arrays_size();
>> >>  }
>> >>
>> >> +unsigned
>> >> +glsl_std430_size(const struct glsl_type *type, bool row_major)
>> >> +{
>> >> +   return type->std430_size(row_major);
>> >> +}
>> >> +
>> >> +unsigned
>> >> +glsl_std430_base_alignment(const struct glsl_type *type, bool
>> >> row_major)
>> >> +{
>> >> +   return type->std430_base_alignment(row_major);
>> >> +}
>> >> +
>> >>  unsigned
>> >>  glsl_count_attribute_slots(const struct glsl_type *type,
>> >>                             bool is_vertex_input)
>> >> diff --git a/src/compiler/nir_types.h b/src/compiler/nir_types.h
>> >> index e2dfd1ef5b7..5b5e09d137f 100644
>> >> --- a/src/compiler/nir_types.h
>> >> +++ b/src/compiler/nir_types.h
>> >> @@ -71,6 +71,10 @@ unsigned glsl_get_length(const struct glsl_type
>> >> *type);
>> >>
>> >>  unsigned glsl_get_aoa_size(const struct glsl_type *type);
>> >>
>> >> +unsigned glsl_std430_size(const struct glsl_type *type, bool
>> >> row_major);
>> >> +
>> >> +unsigned glsl_std430_base_alignment(const struct glsl_type *type, bool
>> >> row_major);
>> >> +
>> >>  unsigned glsl_count_attribute_slots(const struct glsl_type *type,
>> >>                                      bool is_vertex_input);
>> >>
>> >> --
>> >> 2.14.3
>> >>
>> >> _______________________________________________
>> >> mesa-dev mailing list
>> >> mesa-dev at lists.freedesktop.org
>> >> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>> >
>> >
>
>