[Mesa-dev] [PATCH 2/2] i965/tcs: support gl_PatchVerticesIn as a system value from SPIR-V

[Iago Toral]

This patch is still missing a review, any takers? This is required to
pass one of the SPIR-V CTS tests.

Iago

On Thu, 2017-11-16 at 08:53 +0100, Iago Toral Quiroga wrote:
> We currently handle this by lowering it to a uniform for gen8+ but
> the SPIR-V path generates this as a system value, so handle that
> case as well.
> ---
>  src/mesa/drivers/dri/i965/brw_tcs.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_tcs.c
> b/src/mesa/drivers/dri/i965/brw_tcs.c
> index 4424efea4f0..b07b11f485d 100644
> --- a/src/mesa/drivers/dri/i965/brw_tcs.c
> +++ b/src/mesa/drivers/dri/i965/brw_tcs.c
> @@ -296,7 +296,14 @@ brw_tcs_populate_key(struct brw_context *brw,
>        per_patch_slots |= prog->info.patch_outputs_written;
>     }
>  
> -   if (devinfo->gen < 8 || !tcp)
> +   /* For GLSL, gen8+ lowers gl_PatchVerticesIn to a uniform,
> however
> +    * the SPIR-V path always lowers it to a system value.
> +    */
> +   bool reads_patch_vertices_as_system_value =
> +      tcp && (tcp->program.nir->info.system_values_read &
> +              BITFIELD64_BIT(SYSTEM_VALUE_VERTICES_IN));
> +
> +   if (devinfo->gen < 8 || !tcp ||
> reads_patch_vertices_as_system_value)
>        key->input_vertices = brw->ctx.TessCtrlProgram.patch_vertices;
>     key->outputs_written = per_vertex_slots;
>     key->patch_outputs_written = per_patch_slots;