[Mesa-dev] [PATCH] i965/nir: Provide a default LOD for buffer textures

[Eduardo Lima Mitev]

Patch is:

Reviewed-by: Eduardo Lima Mitev <elima at igalia.com>

Thanks!

On 12/13/2015 01:12 AM, Jason Ekstrand wrote:
> Our hardware requires an LOD for all texelFetch commands even if they are
> on buffer textures.  GLSL IR gives us an LOD of 0 in that case, but the LOD
> is really rather meaningless.  This commit allows other NIR producers to be
> more lazy and not provide one at all.
> ---
>  src/mesa/drivers/dri/i965/brw_fs_nir.cpp   | 4 ++++
>  src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 4 ++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
> index c52bc04..6f51ce1 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
> @@ -2780,6 +2780,10 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
>  
>     fs_reg coordinate, shadow_comparitor, lod, lod2, sample_index, mcs, tex_offset;
>  
> +   /* Our hardware requires a LOD for buffer textures */
> +   if (instr->sampler_dim == GLSL_SAMPLER_DIM_BUF)
> +      lod = brw_imm_d(0);
> +
>     for (unsigned i = 0; i < instr->num_srcs; i++) {
>        fs_reg src = get_nir_src(instr->src[i].src);
>        switch (instr->src[i].src_type) {
> diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
> index cf1f82f..cfb66a5 100644
> --- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
> @@ -1558,6 +1558,10 @@ vec4_visitor::nir_emit_texture(nir_tex_instr *instr)
>                                   nir_tex_instr_dest_size(instr));
>     dst_reg dest = get_nir_dest(instr->dest, instr->dest_type);
>  
> +   /* Our hardware requires a LOD for buffer textures */
> +   if (instr->sampler_dim == GLSL_SAMPLER_DIM_BUF)
> +      lod = brw_imm_d(0);
> +
>     /* Load the texture operation sources */
>     for (unsigned i = 0; i < instr->num_srcs; i++) {
>        switch (instr->src[i].src_type) {
>