[Mesa-stable] [Mesa-dev] [PATCH] i965/fs: Gracefully handle TXS on multisampled textures with no LOD

[Lionel Landwerlin]

On 29/03/17 23:22, Jason Ekstrand wrote:
> This can happen for multisampled textures since they are never mipmapped
> and textureSize(gsampler2DMS*) does not take an LOD parameter.  This
> fixes a shader validation error in the new Sascha deferredmultisampling
> demo.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100391
> Cc: "13.0 17.0" <mesa-stable at lists.freedesktop.org>
> ---
>
> We could also easily enough handle this in spirv_to_nir like we do with
> GLSL.  However, it seems perfectly reasonable that multisampled txs should
> allow no LOD in NIR.
>
>   src/intel/compiler/brw_fs_nir.cpp | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
> index bc1ccfb..60604e1 100644
> --- a/src/intel/compiler/brw_fs_nir.cpp
> +++ b/src/intel/compiler/brw_fs_nir.cpp
> @@ -4381,9 +4381,12 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
>      srcs[TEX_LOGICAL_SRC_GRAD_COMPONENTS] = brw_imm_d(lod_components);
>   
>      if (instr->op == nir_texop_query_levels ||
> +       (instr->op == nir_texop_txs &&
> +        instr->sampler_dim == GLSL_SAMPLER_DIM_MS) ||
>          (instr->op == nir_texop_tex && stage != MESA_SHADER_FRAGMENT)) {
> -      /* textureQueryLevels() and texture() are implemented in terms of TXS
> -       * and TXL respectively, so we need to pass a valid LOD argument.
> +      /* textureQueryLevels(), textureSize(), and texture() are implemented in
> +       * terms of TXS and TXL respectively, so we need to pass a valid LOD

Maybe replace with "TXS, TXS and TXL respectively"

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

> +       * argument.
>          */
>         assert(srcs[TEX_LOGICAL_SRC_LOD].file == BAD_FILE);
>         srcs[TEX_LOGICAL_SRC_LOD] = brw_imm_ud(0u);