[Mesa-dev] [PATCH] tgsi: collect texture sampler target info in tgsi_scan_shader()

[Roland Scheidegger]

Am 29.03.2016 um 03:43 schrieb Brian Paul:
> Texture sample instructions specify a sampler unit and texture target
> such as "1D", "2D", "CUBE", etc.  Sampler view declarations also specify
> the sampler unit and texture target.
> 
> This patch checks that the texture instructions agree with the declarations
> and collects the texture target type for each sampler unit.
> ---
>  src/gallium/auxiliary/tgsi/tgsi_scan.c | 33 +++++++++++++++++++++++++++++++--
>  src/gallium/auxiliary/tgsi/tgsi_scan.h |  1 +
>  2 files changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.c b/src/gallium/auxiliary/tgsi/tgsi_scan.c
> index d32c3a1..796101d 100644
> --- a/src/gallium/auxiliary/tgsi/tgsi_scan.c
> +++ b/src/gallium/auxiliary/tgsi/tgsi_scan.c
> @@ -181,11 +181,28 @@ scan_instruction(struct tgsi_shader_info *info,
>           info->indirect_files_read |= (1 << src->Register.File);
>        }
>  
> -      /* MSAA samplers */
> +      /* Texture samplers */
>        if (src->Register.File == TGSI_FILE_SAMPLER) {
> +         const unsigned index = src->Register.Index;
> +         const unsigned target = fullinst->Texture.Texture;
> +
>           assert(fullinst->Instruction.Texture);
> -         assert(src->Register.Index < Elements(info->is_msaa_sampler));
> +         assert(index < Elements(info->is_msaa_sampler));
> +         assert(index < PIPE_MAX_SAMPLERS);
> +         assert(target < TGSI_TEXTURE_UNKNOWN);
> +
> +         /* check/save target */
> +         if (info->sampler_targets[index] == TGSI_TEXTURE_UNKNOWN) {
> +            /* probably no sampler view declaration */
> +            info->sampler_targets[index] = target;
> +         } else {
> +            /* Make sure the texture instruction's sampler/target info
> +             * agrees with the sampler view declaration.
> +             */
> +            assert(info->sampler_targets[index] == target);
> +         }
>  
> +         /* MSAA samplers */
>           if (fullinst->Instruction.Texture &&
>               (fullinst->Texture.Texture == TGSI_TEXTURE_2D_MSAA ||
>                fullinst->Texture.Texture == TGSI_TEXTURE_2D_ARRAY_MSAA)) {
> @@ -431,6 +448,16 @@ scan_declaration(struct tgsi_shader_info *info,
>           }
>        } else if (file == TGSI_FILE_SAMPLER) {
>           info->samplers_declared |= 1 << reg;
> +      } else if (file == TGSI_FILE_SAMPLER_VIEW) {
> +         unsigned target = fulldecl->SamplerView.Resource;
> +         assert(target < TGSI_TEXTURE_UNKNOWN);
> +         if (info->sampler_targets[reg] == TGSI_TEXTURE_UNKNOWN) {
> +            /* Save sampler target for this sampler index */
> +            info->sampler_targets[reg] = target;
> +         } else {
> +            /* if previously declared, make sure targets agree */
> +            assert(info->sampler_targets[reg] == target);
> +         }
>        } else if (file == TGSI_FILE_IMAGE) {
>           if (fulldecl->Image.Resource == TGSI_TEXTURE_BUFFER)
>              info->images_buffers |= 1 << reg;
> @@ -493,6 +520,8 @@ tgsi_scan_shader(const struct tgsi_token *tokens,
>     for (i = 0; i < Elements(info->const_file_max); i++)
>        info->const_file_max[i] = -1;
>     info->properties[TGSI_PROPERTY_GS_INVOCATIONS] = 1;
> +   for (i = 0; i < Elements(info->sampler_targets); i++)
> +      info->sampler_targets[i] = TGSI_TEXTURE_UNKNOWN;
>  
>     /**
>      ** Setup to begin parsing input shader
> diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.h b/src/gallium/auxiliary/tgsi/tgsi_scan.h
> index 76d8925..25855c8 100644
> --- a/src/gallium/auxiliary/tgsi/tgsi_scan.h
> +++ b/src/gallium/auxiliary/tgsi/tgsi_scan.h
> @@ -65,6 +65,7 @@ struct tgsi_shader_info
>     int file_max[TGSI_FILE_COUNT];  /**< highest index of declared registers */
>     int const_file_max[PIPE_MAX_CONSTANT_BUFFERS];
>     unsigned samplers_declared; /**< bitmask of declared samplers */
> +   ubyte sampler_targets[PIPE_MAX_SAMPLERS];  /**< TGSI_TEXTURE_x values */
>  
>     ubyte input_array_first[PIPE_MAX_SHADER_INPUTS];
>     ubyte input_array_last[PIPE_MAX_SHADER_INPUTS];
> 

This patch will likely assert all the time with other state trackers,
which use sample instructions (because the sampler index you get in such
instructions can and will be different to what you declared with the
"corresponding" sampler view, as they are in no way linked together).
Thus the targets will not match. (And, IIRC, you don't get a valid
target out of these instructions anyway, it will be encoded but might
just be TGSI_TEXTURE_UNKNOWN). I think the only way to make this work
would be to verify that stuff with the "classic" texture instructions,
but not the sample ones.

Roland