[Mesa-dev] [PATCH 2/2] st/glsl_to_nir: delay adding built-in uniforms to Parameters list

Nicolai Hähnle nhaehnle at gmail.com
Fri Nov 3 09:59:41 UTC 2017


On 02.11.2017 20:45, Timothy Arceri wrote:
> 
> 
> On 03/11/17 03:25, Nicolai Hähnle wrote:
>> On 01.11.2017 06:20, Timothy Arceri wrote:
>>> Delaying adding built-in uniforms until after we convert to NIR
>>> gives us a better chance to optimise them away. Also NIR allows
>>> us to iterate over the uniforms directly so should be faster.
>>> ---
>>>   src/mesa/state_tracker/st_glsl_to_nir.cpp  | 68 
>>> +++++++++++++++---------------
>>>   src/mesa/state_tracker/st_glsl_to_tgsi.cpp |  2 +-
>>>   2 files changed, 34 insertions(+), 36 deletions(-)
>>>
>>> diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp 
>>> b/src/mesa/state_tracker/st_glsl_to_nir.cpp
>>> index 5b37d2cd63..bbef830a2e 100644
>>> --- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
>>> +++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
>>> @@ -235,20 +235,53 @@ st_glsl_to_nir(struct st_context *st, struct 
>>> gl_program *prog,
>>>      options = (const nir_shader_compiler_options *)
>>>         pscreen->get_compiler_options(pscreen, PIPE_SHADER_IR_NIR, 
>>> ptarget);
>>>      assert(options);
>>>      if (prog->nir)
>>>         return prog->nir;
>>>      nir = glsl_to_nir(shader_program, stage, options);
>>> +   /* Make a pass over the IR to add state references for any built-in
>>> +    * uniforms that are used.  This has to be done now (during 
>>> linking).
>>> +    * Code generation doesn't happen until the first time this 
>>> shader is
>>> +    * used for rendering.  Waiting until then to generate the 
>>> parameters is
>>> +    * too late.  At that point, the values for the built-in uniforms 
>>> won't
>>> +    * get sent to the shader.
>>> +    */
>>> +   nir_foreach_variable(var, &nir->uniforms) {
>>> +      if (strncmp(var->name, "gl_", 3) == 0) {
>>> +         const nir_state_slot *const slots = var->state_slots;
>>> +         assert(var->state_slots != NULL);
>>> +
>>> +         for (unsigned int i = 0; i < var->num_state_slots; i++) {
>>> +            _mesa_add_state_reference(prog->Parameters,
>>> +                                      (gl_state_index 
>>> *)slots[i].tokens);
>>> +         }
>>> +      }
>>> +   }
>>> +
>>> +   /* Avoid reallocation of the program parameter list, because the 
>>> uniform
>>> +    * storage is only associated with the original parameter list.
>>> +    * This should be enough for Bitmap and DrawPixels constants.
>>> +    */
>>> +   _mesa_reserve_parameter_storage(prog->Parameters, 8);
>>> +
>>> +   /* This has to be done last.  Any operation the can cause
>>> +    * prog->ParameterValues to get reallocated (e.g., anything that 
>>> adds a
>>> +    * program constant) has to happen before creating this linkage.
>>> +    */
>>> +   _mesa_associate_uniform_storage(st->ctx, shader_program, prog, 
>>> true);
>>> +
>>> +   st_set_prog_affected_state_flags(prog);
>>> +
>>>      NIR_PASS_V(nir, nir_lower_io_to_temporaries,
>>>            nir_shader_get_entrypoint(nir),
>>>            true, true);
>>>      NIR_PASS_V(nir, nir_lower_global_vars_to_local);
>>>      NIR_PASS_V(nir, nir_split_var_copies);
>>>      NIR_PASS_V(nir, nir_lower_var_copies);
>>>      NIR_PASS_V(nir, st_nir_lower_builtin);
>>>      NIR_PASS_V(nir, nir_lower_atomics, shader_program);
>>>      /* fragment shaders may need : */
>>> @@ -381,67 +414,32 @@ st_nir_get_mesa_program(struct gl_context *ctx,
>>>      prog = shader->Program;
>>>      prog->Parameters = _mesa_new_parameter_list();
>>>      do_set_program_inouts(shader->ir, prog, shader->Stage);
>>>      _mesa_copy_linked_program_data(shader_program, shader);
>>>      _mesa_generate_parameters_list_for_uniforms(ctx, shader_program, 
>>> shader,
>>>                                                  prog->Parameters);
>>> -   /* Make a pass over the IR to add state references for any built-in
>>> -    * uniforms that are used.  This has to be done now (during 
>>> linking).
>>> -    * Code generation doesn't happen until the first time this 
>>> shader is
>>> -    * used for rendering.  Waiting until then to generate the 
>>> parameters is
>>> -    * too late.  At that point, the values for the built-in uniforms 
>>> won't
>>> -    * get sent to the shader.
>>> -    */
>>> -   foreach_in_list(ir_instruction, node, shader->ir) {
>>> -      ir_variable *var = node->as_variable();
>>> -
>>> -      if ((var == NULL) || (var->data.mode != ir_var_uniform) ||
>>> -          (strncmp(var->name, "gl_", 3) != 0))
>>> -         continue;
>>> -
>>> -      const ir_state_slot *const slots = var->get_state_slots();
>>> -      assert(slots != NULL);
>>> -
>>> -      for (unsigned int i = 0; i < var->get_num_state_slots(); i++) {
>>> -         _mesa_add_state_reference(prog->Parameters,
>>> -                                   (gl_state_index *) slots[i].tokens);
>>> -      }
>>> -   }
>>> -
>>>      if (ctx->_Shader->Flags & GLSL_DUMP) {
>>>         _mesa_log("\n");
>>>         _mesa_log("GLSL IR for linked %s program %d:\n",
>>>                _mesa_shader_stage_to_string(shader->Stage),
>>>                shader_program->Name);
>>>         _mesa_print_ir(_mesa_get_log_file(), shader->ir, NULL);
>>>         _mesa_log("\n\n");
>>>      }
>>>      prog->ExternalSamplersUsed = gl_external_samplers(prog);
>>>      _mesa_update_shader_textures_used(shader_program, prog);
>>> -   /* Avoid reallocation of the program parameter list, because the 
>>> uniform
>>> -    * storage is only associated with the original parameter list.
>>> -    * This should be enough for Bitmap and DrawPixels constants.
>>> -    */
>>> -   _mesa_reserve_parameter_storage(prog->Parameters, 8);
>>> -
>>> -   /* This has to be done last.  Any operation the can cause
>>> -    * prog->ParameterValues to get reallocated (e.g., anything that 
>>> adds a
>>> -    * program constant) has to happen before creating this linkage.
>>> -    */
>>> -   _mesa_associate_uniform_storage(ctx, shader_program, prog, true);
>>> -
>>>      struct st_vertex_program *stvp;
>>>      struct st_common_program *stp;
>>>      struct st_fragment_program *stfp;
>>>      struct st_compute_program *stcp;
>>>      switch (shader->Stage) {
>>>      case MESA_SHADER_VERTEX:
>>>         stvp = (struct st_vertex_program *)prog;
>>>         stvp->shader_program = shader_program;
>>>         break;
>>> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp 
>>> b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>>> index eaed052a17..419183d5c9 100644
>>> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>>> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
>>> @@ -6969,24 +6969,24 @@ st_link_shader(struct gl_context *ctx, struct 
>>> gl_shader_program *prog)
>>>            pipe_shader_type_from_mesa(shader->Stage);
>>>         enum pipe_shader_ir preferred_ir = (enum pipe_shader_ir)
>>>            pscreen->get_shader_param(pscreen, ptarget,
>>>                                      PIPE_SHADER_CAP_PREFERRED_IR);
>>>         struct gl_program *linked_prog = NULL;
>>>         if (preferred_ir == PIPE_SHADER_IR_NIR) {
>>>            linked_prog = st_nir_get_mesa_program(ctx, prog, shader);
>>>         } else {
>>>            linked_prog = get_mesa_program_tgsi(ctx, prog, shader);
>>> +         st_set_prog_affected_state_flags(linked_prog);
>>>         }
>>>         if (linked_prog) {
>>> -         st_set_prog_affected_state_flags(linked_prog);
>>>            if (!ctx->Driver.ProgramStringNotify(ctx,
>>> _mesa_shader_stage_to_program(i),
>>>                                                 linked_prog)) {
>>>               _mesa_reference_program(ctx, &shader->Program, NULL);
>>>               return GL_FALSE;
>>>            }
>>>         }
>>
>> This hunk doesn't seem to fit with the rest of the patch.
> 
> It checks if the paramlist is empty or not so we need to call it later 
> also. I can update the commit message if that would help.

Ah yes, I see it now, thanks. R-b for this patch as well.

Cheers,
Nicolai

> 
> 
>>
>>
>>>      }
>>>      return GL_TRUE;
>>>
>>
>>


-- 
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.


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