[Mesa-dev] [PATCH v3 15/19] nir: use load_local_group_size

[Rob Clark]

On Fri, Mar 23, 2018 at 4:59 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> On Fri, Mar 23, 2018 at 1:35 PM, Karol Herbst <kherbst at redhat.com> wrote:
>>
>> On Fri, Mar 23, 2018 at 9:18 PM, Jason Ekstrand <jason at jlekstrand.net>
>> wrote:
>> > On Fri, Mar 23, 2018 at 12:33 PM, Karol Herbst <kherbst at redhat.com>
>> > wrote:
>> >>
>> >> From: Rob Clark <robdclark at gmail.com>
>> >>
>> >> If local_size is not known at compile time, which is the case with
>> >> clover, use the load_local_group_size intrinsic instead.
>> >>
>> >> Signed-off-by: Karol Herbst <kherbst at redhat.com>
>> >> ---
>> >>  src/compiler/nir/nir_lower_system_values.c | 25
>> >> +++++++++++++++++--------
>> >>  1 file changed, 17 insertions(+), 8 deletions(-)
>> >>
>> >> diff --git a/src/compiler/nir/nir_lower_system_values.c
>> >> b/src/compiler/nir/nir_lower_system_values.c
>> >> index d507c28f421..ff4e09c8e61 100644
>> >> --- a/src/compiler/nir/nir_lower_system_values.c
>> >> +++ b/src/compiler/nir/nir_lower_system_values.c
>> >> @@ -57,19 +57,28 @@ convert_block(nir_block *block, nir_builder *b)
>> >>            *    "The value of gl_GlobalInvocationID is equal to
>> >>            *    gl_WorkGroupID * gl_WorkGroupSize +
>> >> gl_LocalInvocationID"
>> >>            */
>> >> +         nir_ssa_def *local_size_def;
>> >>
>> >> -         nir_const_value local_size;
>> >> -         memset(&local_size, 0, sizeof(local_size));
>> >> -         local_size.u64[0] = b->shader->info.cs.local_size[0];
>> >> -         local_size.u64[1] = b->shader->info.cs.local_size[1];
>> >> -         local_size.u64[2] = b->shader->info.cs.local_size[2];
>> >> +         /* if local_size[] is already known, use that, otherwise use
>> >> +          * load_local_group_size intrinsic:
>> >> +          */
>> >> +         if (b->shader->info.cs.local_size[0]) {
>> >> +            nir_const_value local_size;
>> >> +            memset(&local_size, 0, sizeof(local_size));
>> >> +            local_size.u64[0] = b->shader->info.cs.local_size[0];
>> >> +            local_size.u64[1] = b->shader->info.cs.local_size[1];
>> >> +            local_size.u64[2] = b->shader->info.cs.local_size[2];
>> >> +
>> >> +            local_size_def = nir_build_imm(b, 3, bit_size,
>> >> local_size);
>> >>
>> >> +         } else {
>> >> +            local_size_def = nir_load_local_group_size(b, bit_size);
>> >> +         }
>> >
>> >
>> > I commented on an earlier patch about how the approach to building the
>> > 32/64-bit immediates is wrong.
>> >
>>
>> oh right, I totally forgot about that.
>>
>> > Setting that aside, this patch looks fine to me in principal.  There's a
>> > part of me that doesn't like using cs.local_size[0] being the trigger
>> > but I
>> > think it's probably ok.  Maybe we should assert that cs_local_size is
>> > either
>> > all zero (second case) or all not zero (first case) just to be safe.
>> >
>>
>> I think the main problem here is, that even with OpenCL kernels you
>> can specify it, but then overwrite it at runtime again. So yes I
>> agree, that we need something better here.
>
>
> Oh, that's tricky then.  We could make nir_lower_system_values take a flag
> or OpenCL callers could just whack it all to 0 after spirv_to_nir.c.  Or you
> could do recompiles or something.
>

I'm half-way towards thinking we should have MESA_SHADER_KERNEL vs
MESA_SHADER_COMPUTE to deal with cl/cuda/etc vs glsl compute shaders..

So far, I've been trying to avoid that, but maybe it would be a better
solution..

BR,
-R

> I think this looks good for now and we can let OpenCL users of NIR whack it
> to 0.  It's a fairly obvious behavior of "if you don't have it, load it" and
> we can let the CL driver sort out how they want to handle recompiles.
>
>>
>> >>
>> >>
>> >>           nir_ssa_def *group_id = nir_load_work_group_id(b, bit_size);
>> >>           nir_ssa_def *local_id = nir_load_local_invocation_id(b,
>> >> bit_size);
>> >>
>> >> -         sysval = nir_iadd(b, nir_imul(b, group_id,
>> >> -                                       nir_build_imm(b, 3, bit_size,
>> >> local_size)),
>> >> -                              local_id);
>> >> +         sysval = nir_iadd(b, nir_imul(b, group_id, local_size_def),
>> >> +                           local_id);
>> >>           break;
>> >>        }
>> >>
>> >> --
>> >> 2.14.3
>> >>
>> >> _______________________________________________
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>> >> mesa-dev at lists.freedesktop.org
>> >> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>> >
>> >
>
>
>
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