[Mesa-dev] [PATCH v2 24/25] i965: Call spirv_to_nir() instead of glsl_to_nir() for SPIR-V shaders

[Eduardo Lima Mitev]

On 12/01/2017 04:44 AM, Timothy Arceri wrote:
>
>
> On 01/12/17 04:28, Eduardo Lima Mitev wrote:
>> This is the main fork of the shader compilation code-path, where a NIR
>> shader is obtained by calling spirv_to_nir() or glsl_to_nir(),
>> depending on its nature..
>>
>> v2: Use 'spirv_data' member from gl_linked_shader to know which method
>>     to call. (Timothy Arceri)
>> ---
>>   src/mesa/drivers/dri/i965/brw_program.c | 14 ++++++++++++--
>>   1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/brw_program.c
>> b/src/mesa/drivers/dri/i965/brw_program.c
>> index 755d4973cc0..596118f2fe5 100644
>> --- a/src/mesa/drivers/dri/i965/brw_program.c
>> +++ b/src/mesa/drivers/dri/i965/brw_program.c
>> @@ -31,6 +31,7 @@
>>     #include <pthread.h>
>>   #include "main/imports.h"
>> +#include "main/glspirv.h"
>>   #include "program/prog_parameter.h"
>>   #include "program/prog_print.h"
>>   #include "program/prog_to_nir.h"
>> @@ -73,9 +74,18 @@ brw_create_nir(struct brw_context *brw,
>>         ctx->Const.ShaderCompilerOptions[stage].NirOptions;
>>      nir_shader *nir;
>>   -   /* First, lower the GLSL IR or Mesa IR to NIR */
>> +   /* First, lower the GLSL/Mesa IR or SPIR-V to NIR */
>>      if (shader_prog) {
>> -      nir = glsl_to_nir(shader_prog, stage, options);
>> +      bool is_spirv_shader =
>> +         (shader_prog->_LinkedShaders[stage]->spirv_data != NULL);
>> +
>> +      if (!is_spirv_shader) {
>> +         nir = glsl_to_nir(shader_prog, stage, options);
>> +      } else {
>> +         nir = _mesa_spirv_to_nir(ctx, shader_prog, stage, options);
>> +      }
>> +      assert (nir);
>
> Rather than messing around with bools, null checks and !'s I'd just
> change this to:
>
>       /* First, lower the GLSL/Mesa IR or SPIR-V to NIR */
>       if (shader_prog->_LinkedShaders[stage]->spirv_data) {
>          nir = _mesa_spirv_to_nir(ctx, shader_prog, stage, options);
>       } else {
>          nir = glsl_to_nir(shader_prog, stage, options);
>       }
>       assert (nir);
>
>

My intention was to make it clearer that we are using a pointer nullness
to decide code-path.
I don't care much so I will use your inlined version above, maybe just
adding a comment.

Thanks,

Eduardo

>> +
>>         nir_remove_dead_variables(nir, nir_var_shader_in |
>> nir_var_shader_out);
>>         nir_lower_returns(nir);
>>         nir_validate_shader(nir);
>>
>