[Mesa-dev] [PATCH 2/2] radv/gfx10: correctly determine the number of vertices per primitive

[Samuel Pitoiset]

On 7/22/19 6:01 PM, Ilia Mirkin wrote:
> On Mon, Jul 22, 2019 at 11:49 AM Samuel Pitoiset
> <samuel.pitoiset at gmail.com> wrote:
>> For TES as NGG.
>>
>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
>> ---
>>   src/amd/vulkan/radv_nir_to_llvm.c | 17 ++++++++++++++++-
>>   1 file changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/amd/vulkan/radv_nir_to_llvm.c b/src/amd/vulkan/radv_nir_to_llvm.c
>> index 336bae28614..6e5a283f923 100644
>> --- a/src/amd/vulkan/radv_nir_to_llvm.c
>> +++ b/src/amd/vulkan/radv_nir_to_llvm.c
>> @@ -112,6 +112,7 @@ struct radv_shader_context {
>>          unsigned gs_max_out_vertices;
>>          unsigned gs_output_prim;
>>
>> +       unsigned tes_point_mode;
>>          unsigned tes_primitive_mode;
>>
>>          uint32_t tcs_patch_outputs_read;
>> @@ -3304,7 +3305,6 @@ handle_ngg_outputs_post(struct radv_shader_context *ctx)
>>   {
>>          LLVMBuilderRef builder = ctx->ac.builder;
>>          struct ac_build_if_state if_state;
>> -       unsigned num_vertices = 3;
>>          LLVMValueRef tmp;
>>
>>          assert((ctx->stage == MESA_SHADER_VERTEX ||
>> @@ -3322,6 +3322,20 @@ handle_ngg_outputs_post(struct radv_shader_context *ctx)
>>                  ac_unpack_param(&ctx->ac, ctx->gs_vtx_offset[2], 0, 16),
>>          };
>>
>> +       /* Determine the number of vertices per primitive. */
>> +       unsigned num_vertices;
>> +
>> +       if (ctx->stage == MESA_SHADER_VERTEX) {
>> +               num_vertices = 3; /* TODO: optimize for points & lines */
>> +       } else {
>> +               if (ctx->tes_point_mode)
>> +                       num_vertices = 1;
>> +               else if (ctx->tes_primitive_mode == GL_LINES)
>> +                       num_vertices = 2;
>> +               else
>> +                       num_vertices = 3;
>> +       }
>> +
>>          /* TODO: streamout */
>>
>>          /* Copy Primitive IDs from GS threads to the LDS address corresponding
>> @@ -4435,6 +4449,7 @@ LLVMModuleRef ac_translate_nir_to_llvm(struct ac_llvm_compiler *ac_llvm,
>>                                  ctx.tcs_num_inputs = util_last_bit64(shader_info->info.vs.ls_outputs_written);
>>                          ctx.tcs_num_patches = get_tcs_num_patches(&ctx);
>>                  } else if (shaders[i]->info.stage == MESA_SHADER_TESS_EVAL) {
>> +                       ctx.tes_point_mode = shaders[i]->info.tess.point_mode;
> Drive-by-comment without reading the full context...
>
> What if there's e.g. a GS which produces not-points? This bool will be
> set, and the logic above will say num_vertices = 1, which presumably
> is bad.
With GS, TES is emitted as ES and this function isn't called because 
it's for NGG only.
>
>    -ilia
>
>>                          ctx.tes_primitive_mode = shaders[i]->info.tess.primitive_mode;
>>                          ctx.abi.load_tess_varyings = load_tes_input;
>>                          ctx.abi.load_tess_coord = load_tess_coord;
>> --
>> 2.22.0
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev