[Mesa-dev] [PATCH] nvc0: bind a fake tess control program when there isn't one available

[Samuel Pitoiset]

On 07/26/2015 06:56 AM, Ilia Mirkin wrote:
> Apparently this is necessary in order for tess factors to work in a tess
> eval program without a tess control program bound. Probably because it
> uses the fake program's shader header to work out the number of patch
> constants.
>
> Fixes vs-tes-tessinner-tessouter-inputs
>
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>   src/gallium/drivers/nouveau/nvc0/nvc0_context.c      |  5 +++++
>   src/gallium/drivers/nouveau/nvc0/nvc0_context.h      |  3 +++
>   src/gallium/drivers/nouveau/nvc0/nvc0_program.c      | 17 +++++++++++++++++
>   src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c |  6 +++++-
>   4 files changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_context.c b/src/gallium/drivers/nouveau/nvc0/nvc0_context.c
> index 84f8db6..46970db 100644
> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_context.c
> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_context.c
> @@ -132,6 +132,9 @@ nvc0_context_unreference_resources(struct nvc0_context *nvc0)
>         pipe_resource_reference(res, NULL);
>      }
>      util_dynarray_fini(&nvc0->global_residents);
> +
> +   if (nvc0->tcp_empty)
> +      nvc0->base.pipe.delete_tcs_state(&nvc0->base.pipe, nvc0->tcp_empty);
>   }
>   
>   static void
> @@ -326,6 +329,8 @@ nvc0_create(struct pipe_screen *pscreen, void *priv)
>   
>      /* shader builtin library is per-screen, but we need a context for m2mf */
>      nvc0_program_library_upload(nvc0);
> +   nvc0_program_init_tcp_empty(nvc0);
> +   nvc0->dirty |= NVC0_NEW_TCTLPROG;
>   
>      /* add permanently resident buffers to bufctxts */
>   
> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_context.h b/src/gallium/drivers/nouveau/nvc0/nvc0_context.h
> index f449942..df1a891 100644
> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_context.h
> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_context.h
> @@ -128,6 +128,8 @@ struct nvc0_context {
>      struct nvc0_program *fragprog;
>      struct nvc0_program *compprog;
>   
> +   struct nvc0_program *tcp_empty;
> +
>      struct nvc0_constbuf constbuf[6][NVC0_MAX_PIPE_CONSTBUFS];
>      uint16_t constbuf_dirty[6];
>      uint16_t constbuf_valid[6];
> @@ -227,6 +229,7 @@ void nvc0_program_destroy(struct nvc0_context *, struct nvc0_program *);
>   void nvc0_program_library_upload(struct nvc0_context *);
>   uint32_t nvc0_program_symbol_offset(const struct nvc0_program *,
>                                       uint32_t label);
> +void nvc0_program_init_tcp_empty(struct nvc0_context *);
>   
>   /* nvc0_query.c */
>   void nvc0_init_query_functions(struct nvc0_context *);
> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_program.c b/src/gallium/drivers/nouveau/nvc0/nvc0_program.c
> index 4941831..e9975ce 100644
> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_program.c
> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_program.c
> @@ -22,6 +22,8 @@
>   
>   #include "pipe/p_defines.h"
>   
> +#include "tgsi/tgsi_ureg.h"
> +
>   #include "nvc0/nvc0_context.h"
>   
>   #include "codegen/nv50_ir_driver.h"
> @@ -803,3 +805,18 @@ nvc0_program_symbol_offset(const struct nvc0_program *prog, uint32_t label)
>            return prog->code_base + base + syms[i].offset;
>      return prog->code_base; /* no symbols or symbol not found */
>   }
> +
> +void
> +nvc0_program_init_tcp_empty(struct nvc0_context *nvc0)
> +{
> +   struct ureg_program *ureg;
> +
> +   ureg = ureg_create(TGSI_PROCESSOR_TESS_CTRL);
> +   if (!ureg)
> +      return;
> +
> +   ureg_property(ureg, TGSI_PROPERTY_TCS_VERTICES_OUT, 1);
> +   ureg_END(ureg);
> +
> +   nvc0->tcp_empty = ureg_create_shader_and_destroy(ureg, &nvc0->base.pipe);
> +}
> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c b/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c
> index 8aa127a..e21515f 100644
> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c
> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c
> @@ -148,8 +148,12 @@ nvc0_tctlprog_validate(struct nvc0_context *nvc0)
>         BEGIN_NVC0(push, NVC0_3D(SP_GPR_ALLOC(2)), 1);
>         PUSH_DATA (push, tp->num_gprs);
>      } else {
> -      BEGIN_NVC0(push, NVC0_3D(SP_SELECT(2)), 1);
> +      tp = nvc0->tcp_empty;
> +      if (!nvc0_program_validate(nvc0, tp))
> +         assert(!"unable to validate empty tcp");
> +      BEGIN_NVC0(push, NVC0_3D(SP_SELECT(2)), 2);
>         PUSH_DATA (push, 0x20);
> +      PUSH_DATA (push, tp->code_base);
>      }

It would be good to check if tp is not NULL before trying to validate 
the program.
And if the program can't be validated, I don't think we want to push 
tp->code_base, isn't it?

>      nvc0_program_update_context_state(nvc0, tp, 1);
>   }