On 10/19/2016 12:45 PM, Jordan Justen wrote:
> When the local group size is 8 or less, we will execute the program at
> most 1 time. Therefore, the local channel ID will always be 0. By
> using a constant 0 in this case we can prevent using push constant
> data.
>
> This is not expected to be common a occurance in real applications,
> but it has been seen in tests.
>
> We could extend this optimization to 16 and 32 for SIMD16 and SIMD32,
> but it gets a bit more complicated, because this optimization is
> currently being done early on, before we have decided the SIMD size.
>
> Signed-off-by: Jordan Justen <jordan.l.jus...@intel.com>
> ---
> src/mesa/drivers/dri/i965/brw_nir_intrinsics.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_nir_intrinsics.c
> b/src/mesa/drivers/dri/i965/brw_nir_intrinsics.c
> index 9ae161f..60f302e 100644
> --- a/src/mesa/drivers/dri/i965/brw_nir_intrinsics.c
> +++ b/src/mesa/drivers/dri/i965/brw_nir_intrinsics.c
> @@ -39,12 +39,21 @@ struct lower_intrinsics_state {
> static nir_ssa_def *
> read_thread_local_id(struct lower_intrinsics_state *state)
> {
> + nir_builder *b = &state->builder;
> + nir_shader *nir = state->nir;
> + const unsigned *sizes = nir->info.cs.local_size;
> + const group_size = sizes[0] * sizes[1] * sizes[2];
^
Isn't this missing a type? Did you test this? :)
> +
> + /* Some programs have local_size dimensions so small that the thread local
> + * ID will always be 0.
> + */
> + if (group_size <= 8)
> + return nir_imm_int(b, 0);
> +
> assert(state->cs_prog_data->thread_local_id_index >= 0);
> state->cs_thread_id_used = true;
> const int id_index = state->cs_prog_data->thread_local_id_index;
>
> - nir_builder *b = &state->builder;
> - nir_shader *nir = state->nir;
> nir_intrinsic_instr *load =
> nir_intrinsic_instr_create(nir, nir_intrinsic_load_uniform);
> load->num_components = 1;
>
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
