[Mesa-dev] [PATCH] radv: remove dead variables after splitting per member structs

[Timothy Arceri]

On 22/08/18 20:34, Samuel Pitoiset wrote:
> Otherwise, nir_lower_clip_cull_distance_arrays might report
> wrong number of output clips/culls because it relies on
> shader output variables and some of them might be dead.
> 
> This fixes a rendering issue with Dolphin and Super Mario
> Sunshine.
> 
> Fixes: b0c643d8f5 ("spirv: Use NIR per-member splitting")
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107610
> C: 18.2 <mesa-stable at lists.freedesktop.org>
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
>   src/amd/vulkan/radv_shader.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
> index 7d4265cfda..207e5b050e 100644
> --- a/src/amd/vulkan/radv_shader.c
> +++ b/src/amd/vulkan/radv_shader.c
> @@ -259,9 +259,6 @@ radv_shader_compile_to_nir(struct radv_device *device,
>   		 */
>   		NIR_PASS_V(nir, nir_lower_constant_initializers, nir_var_shader_out);
>   
> -		NIR_PASS_V(nir, nir_remove_dead_variables,
> -		           nir_var_shader_in | nir_var_shader_out | nir_var_system_value);
> -
>   		/* Now that we've deleted all but the main function, we can go ahead and
>   		 * lower the rest of the constant initializers.
>   		 */
> @@ -273,6 +270,9 @@ radv_shader_compile_to_nir(struct radv_device *device,
>   		NIR_PASS_V(nir, nir_split_var_copies);
>   		NIR_PASS_V(nir, nir_split_per_member_structs);
>   

I see you already pushed but I would have suggested adding a comment 
here saying this must be called after nir_split_per_member_structs. So 
this didn't get accidentally moved again in future. Seems like a subtle 
bug to track down. Any patch to add the comment would have my r-b.

> +		NIR_PASS_V(nir, nir_remove_dead_variables,
> +		           nir_var_shader_in | nir_var_shader_out | nir_var_system_value);
> +
>   		NIR_PASS_V(nir, nir_lower_system_values);
>   		NIR_PASS_V(nir, nir_lower_clip_cull_distance_arrays);
>   	}
>