[Mesa-dev] [PATCH] nir: Use nir_shader_get_entrypoint in TCS quad workaround code.

[Connor Abbott]

On Thu, Aug 18, 2016 at 2:46 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> We want to insert the code at the end of the program.  Looping over
> all the functions (of which there was only one) was the old way of doing
> this, but now we have nir_shader_get_entrypoint(), so let's use it.
>
> Suggested by Connor Abbott.
>
> Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
> ---
>  .../drivers/dri/i965/brw_nir_tcs_workarounds.c     | 23 +++++++++++-----------
>  1 file changed, 11 insertions(+), 12 deletions(-)
>
> Sorry, I pushed the patch rather quickly...here's a follow-on to use
> nir_shader_get_entrypoint().
>
> Shouldn't be also be using it in nir_lower_gs_intrinsics.c?
>
> diff --git a/src/mesa/drivers/dri/i965/brw_nir_tcs_workarounds.c b/src/mesa/drivers/dri/i965/brw_nir_tcs_workarounds.c
> index 0626981..ac4f9e0 100644
> --- a/src/mesa/drivers/dri/i965/brw_nir_tcs_workarounds.c
> +++ b/src/mesa/drivers/dri/i965/brw_nir_tcs_workarounds.c
> @@ -134,19 +134,18 @@ brw_nir_apply_tcs_quads_workaround(nir_shader *nir)
>  {
>     assert(nir->stage == MESA_SHADER_TESS_CTRL);
>
> -   nir_foreach_function(func, nir) {
> -      if (!func->impl)
> -         continue;
> +   nir_function *func = nir_shader_get_entrypoint(nir);
> +   if (!func->impl)
> +      return;

Minor nit: I think you can drop the if, since it doesn't make sense to
have an entrypoint with only a declaration and no implementation.
Other than that,

Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>

What about my other comment though?

>
> -      nir_builder b;
> -      nir_builder_init(&b, func->impl);
> +   nir_builder b;
> +   nir_builder_init(&b, func->impl);
>
> -      struct set_entry *entry;
> -      set_foreach(func->impl->end_block->predecessors, entry) {
> -         nir_block *pred = (nir_block *) entry->key;
> -         emit_quads_workaround(&b, pred);
> -      }
> -
> -      nir_metadata_preserve(func->impl, 0);
> +   struct set_entry *entry;
> +   set_foreach(func->impl->end_block->predecessors, entry) {
> +      nir_block *pred = (nir_block *) entry->key;
> +      emit_quads_workaround(&b, pred);
>     }
> +
> +   nir_metadata_preserve(func->impl, 0);
>  }
> --
> 2.9.3
>