[Mesa-dev] [PATCH] radeonsi: correct si_vgt_param_key on big endian machines

[Nicolai Hähnle]

Nice, did you actually get it to work entirely on a big endian machine?

Bit fields aren't super portable, but this looks good enough. However, I 
think we should use the PIPE_ARCH_LITTLE_ENDIAN define from u_endian.h

Cheers,
Nicolai

On 20.03.2018 15:21, Bas Vermeulen wrote:
> Using mesa OpenCL failed on a big endian PowerPC machine because
> si_vgt_param_key is using bitfields and a 32 bit int for an
> index into an array.
> 
> Fix si_vgt_param_key to work correctly on both little endian
> and big endian machines.
> 
> Signed-off-by: Bas Vermeulen <bas at daedalean.ai>
> ---
>   src/gallium/drivers/radeonsi/si_pipe.h | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
> 
> diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
> index 2053dcb9fc..32dbdf6e2c 100644
> --- a/src/gallium/drivers/radeonsi/si_pipe.h
> +++ b/src/gallium/drivers/radeonsi/si_pipe.h
> @@ -385,6 +385,7 @@ struct si_shader_ctx_state {
>    */
>   union si_vgt_param_key {
>   	struct {
> +#if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
>   		unsigned prim:4;
>   		unsigned uses_instancing:1;
>   		unsigned multi_instances_smaller_than_primgroup:1;
> @@ -395,6 +396,18 @@ union si_vgt_param_key {
>   		unsigned tess_uses_prim_id:1;
>   		unsigned uses_gs:1;
>   		unsigned _pad:32 - SI_NUM_VGT_PARAM_KEY_BITS;
> +#else /* __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ */
> +		unsigned _pad:32 - SI_NUM_VGT_PARAM_KEY_BITS;
> +		unsigned uses_gs:1;
> +		unsigned tess_uses_prim_id:1;
> +		unsigned uses_tess:1;
> +		unsigned line_stipple_enabled:1;
> +		unsigned count_from_stream_output:1;
> +		unsigned primitive_restart:1;
> +		unsigned multi_instances_smaller_than_primgroup:1;
> +		unsigned uses_instancing:1;
> +		unsigned prim:4;
> +#endif
>   	} u;
>   	uint32_t index;
>   };
>