[Mesa-dev] [PATCH 05/11] mesa: Implement glSpecializeShaderARB

[Timothy Arceri]

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>


On 08/03/18 19:19, Alejandro Piñeiro wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>
> v2: * Use gl_spirv_validation instead of spirv_to_nir.
>     This method just validates the shader. The conversion to NIR will
>     happen later, during linking. (Alejandro Piñeiro)
>
>      * Use gl_shader_spirv_data struct to store the SPIR-V data.
>     (Eduardo Lima)
>
>      * Use the 'spirv_data' member to tell if the gl_shader is
>     a SPIR-V shader, instead of a dedicated flag. (Timothy Arceri)
> ---
>   src/mesa/main/glspirv.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 105 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/main/glspirv.c b/src/mesa/main/glspirv.c
> index 03f761219be..b1185ca5fdf 100644
> --- a/src/mesa/main/glspirv.c
> +++ b/src/mesa/main/glspirv.c
> @@ -23,6 +23,11 @@
>   
>   #include "glspirv.h"
>   #include "errors.h"
> +#include "shaderobj.h"
> +
> +#include "compiler/nir/nir.h"
> +#include "compiler/spirv/nir_spirv.h"
> +
>   #include "util/u_atomic.h"
>   
>   void
> @@ -106,7 +111,105 @@ _mesa_SpecializeShaderARB(GLuint shader,
>                             const GLuint *pConstantValue)
>   {
>      GET_CURRENT_CONTEXT(ctx);
> +   struct gl_shader *sh;
> +   bool has_entry_point;
> +   struct nir_spirv_specialization *spec_entries = NULL;
> +
> +   if (!ctx->Extensions.ARB_gl_spirv) {
> +      _mesa_error(ctx, GL_INVALID_OPERATION, "glSpecializeShaderARB");
> +      return;
> +   }
> +
> +   sh = _mesa_lookup_shader_err(ctx, shader, "glSpecializeShaderARB");
> +   if (!sh)
> +      return;
> +
> +   if (!sh->spirv_data) {
> +      _mesa_error(ctx, GL_INVALID_OPERATION,
> +                  "glSpecializeShaderARB(not SPIR-V)");
> +      return;
> +   }
> +
> +   if (sh->CompileStatus) {
> +      _mesa_error(ctx, GL_INVALID_OPERATION,
> +                  "glSpecializeShaderARB(already specialized)");
> +      return;
> +   }
> +
> +   struct gl_shader_spirv_data *spirv_data = sh->spirv_data;
> +
> +   /* From the GL_ARB_gl_spirv spec:
> +    *
> +    *    "The OpenGL API expects the SPIR-V module to have already been
> +    *     validated, and can return an error if it discovers anything invalid
> +    *     in the module. An invalid SPIR-V module is allowed to result in
> +    *     undefined behavior."
> +    *
> +    * However, the following errors still need to be detected (from the same
> +    * spec):
> +    *
> +    *    "INVALID_VALUE is generated if <pEntryPoint> does not name a valid
> +    *     entry point for <shader>.
> +    *
> +    *     INVALID_VALUE is generated if any element of <pConstantIndex>
> +    *     refers to a specialization constant that does not exist in the
> +    *     shader module contained in <shader>."
> +    *
> +    * We cannot flag those errors a-priori because detecting them requires
> +    * parsing the module. However, flagging them during specialization is okay,
> +    * since it makes no difference in terms of application-visible state.
> +    */
> +   spec_entries = calloc(sizeof(*spec_entries), numSpecializationConstants);
> +
> +   for (unsigned i = 0; i < numSpecializationConstants; ++i) {
> +      spec_entries[i].id = pConstantIndex[i];
> +      spec_entries[i].data32 = pConstantValue[i];
> +      spec_entries[i].defined_on_module = false;
> +   }
> +
> +   has_entry_point =
> +      gl_spirv_validation((uint32_t *)&spirv_data->SpirVModule->Binary[0],
> +                          spirv_data->SpirVModule->Length / 4,
> +                          spec_entries, numSpecializationConstants,
> +                          sh->Stage, pEntryPoint);
> +
> +   /* See previous spec comment */
> +   if (!has_entry_point) {
> +      _mesa_error(ctx, GL_INVALID_VALUE,
> +                  "glSpecializeShaderARB(\"%s\" is not a valid entry point"
> +                  " for shader)", pEntryPoint);
> +      goto end;
> +   }
> +
> +   for (unsigned i = 0; i < numSpecializationConstants; ++i) {
> +      if (spec_entries[i].defined_on_module == false) {
> +         _mesa_error(ctx, GL_INVALID_VALUE,
> +                     "glSpecializeShaderARB(constant \"%i\" does not exist "
> +                     "in shader)", spec_entries[i].id);
> +         goto end;
> +      }
> +   }
> +
> +   spirv_data->SpirVEntryPoint = ralloc_strdup(spirv_data, pEntryPoint);
> +
> +   /* Note that we didn't make a real compilation of the module (spirv_to_nir),
> +    * but just checked some error conditions. Real "compilation" will be done
> +    * later, upon linking.
> +    */
> +   sh->CompileStatus = COMPILE_SUCCESS;
> +
> +   spirv_data->NumSpecializationConstants = numSpecializationConstants;
> +   spirv_data->SpecializationConstantsIndex =
> +      rzalloc_array_size(spirv_data, sizeof(GLuint),
> +                         numSpecializationConstants);
> +   spirv_data->SpecializationConstantsValue =
> +      rzalloc_array_size(spirv_data, sizeof(GLuint),
> +                         numSpecializationConstants);
> +   for (unsigned i = 0; i < numSpecializationConstants; ++i) {
> +      spirv_data->SpecializationConstantsIndex[i] = pConstantIndex[i];
> +      spirv_data->SpecializationConstantsValue[i] = pConstantValue[i];
> +   }
>   
> -   /* Just return GL_INVALID_OPERATION error while this is boilerplate */
> -   _mesa_error(ctx, GL_INVALID_OPERATION, "SpecializeShaderARB");
> + end:
> +   free(spec_entries);
>   }