[Mesa-dev] [PATCH 7/7] nir: add helper macros for running NIR passes

Jason Ekstrand jason at jlekstrand.net
Wed Oct 28 09:09:27 PDT 2015


On Sat, Oct 24, 2015 at 10:08 AM, Rob Clark <robdclark at gmail.com> wrote:
> From: Rob Clark <robclark at freedesktop.org>
>
> Convenient place to put in some extra sanity checking, without making
> things messy for the drivers running the passes.

In the short-term this seems to work (at least for testing nir_clone).
In the long-term, I'm not sure that a macro is really what we want.
I've mentioned a time or two before that what I *think* I'd like to do
(don't know exactly how it will work out yet) is to have a little
datastructure

typedef struct nir_pass {
   bool (*shader_pass_func)(nir_shader *shader, void *data);
   bool (*impl_pass_func)(nir_function_impl *impl, void *data);
   nir_metadata metadata_preserved;
   void *data;
} nir_pass;

and have each of the passes expose one of these as a const global
variable instead of exposing the actual functions.  Then we would have
a runner function (or macro) that could run a pass.  The runner would
take care of validation, trashing metadata, and maybe even cloning.
If no shader_pass_func is provided but you call it on a shader, the
runner would iterate over all of the overloads for you and run the
impl_pass_func on each.  We could also have helpers that take an array
and run all of them or even take an array and run it in a loop until
no more progress is made.

The thing I haven't quite settled on is how to pass extra parameters.
For some passes, we could just put the extra stuff in compiler_options
but we don't want to litter it too bad.  The other option is to do
what I did above and use the classic void pointer.  Then drivers would
have to just make a copy and set the data pointer to whatever they
want.

Maybe I should just go implement this...

> TODO: convert ir3/vc4..
>
> Signed-off-by: Rob Clark <robclark at freedesktop.org>
> ---
>  src/glsl/nir/nir.h                  |  33 ++++++++++
>  src/mesa/drivers/dri/i965/brw_nir.c | 126 ++++++++++++------------------------
>  2 files changed, 76 insertions(+), 83 deletions(-)
>
> diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
> index 3ab720b..053420d 100644
> --- a/src/glsl/nir/nir.h
> +++ b/src/glsl/nir/nir.h
> @@ -1939,10 +1939,43 @@ nir_shader_mutable(nir_shader *shader)
>
>  #ifdef DEBUG
>  void nir_validate_shader(nir_shader *shader);
> +static inline bool
> +__nir_test_clone(void)
> +{
> +   static int enable = -1;
> +   if (enable == -1) {
> +      enable = (getenv("NIR_TEST_CLONE") == NULL) ? 0 : 1;
> +   }
> +   return enable == 1;
> +}
>  #else
>  static inline void nir_validate_shader(nir_shader *shader) { (void) shader; }
> +static inline bool __nir_test_clone(void) { return false; }
>  #endif /* DEBUG */
>
> +
> +#define NIR_PASS(pass, nir, ...) ({                        \
> +      assert(nir_shader_is_mutable(nir));                  \
> +      pass(nir, ##__VA_ARGS__);                            \
> +      nir_validate_shader(nir);                            \
> +      if (__nir_test_clone()) {                            \
> +         nir = nir_shader_clone(ralloc_parent(nir), nir);  \
> +         nir_validate_shader(nir);                         \
> +      }                                                    \
> +   })
> +
> +#define NIR_PASS_PROGRESS(pass, nir, ...) ({               \
> +      assert(nir_shader_is_mutable(nir));                  \
> +      bool __ret = pass(nir, ##__VA_ARGS__);               \
> +      nir_validate_shader(nir);                            \
> +      if (__nir_test_clone()) {                            \
> +         nir = nir_shader_clone(ralloc_parent(nir), nir);  \
> +         nir_validate_shader(nir);                         \
> +      }                                                    \
> +      __ret;                                               \
> +   })
> +
> +
>  void nir_calc_dominance_impl(nir_function_impl *impl);
>  void nir_calc_dominance(nir_shader *shader);
>
> diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
> index 8f09165..bc42fea 100644
> --- a/src/mesa/drivers/dri/i965/brw_nir.c
> +++ b/src/mesa/drivers/dri/i965/brw_nir.c
> @@ -136,47 +136,34 @@ brw_nir_lower_outputs(nir_shader *nir, bool is_scalar)
>     }
>  }
>
> -static void
> +static nir_shader *
>  nir_optimize(nir_shader *nir, bool is_scalar)
>  {
>     bool progress;
>     do {
>        progress = false;
> -      nir_lower_vars_to_ssa(nir);
> -      nir_validate_shader(nir);
>
> -      if (is_scalar) {
> -         nir_lower_alu_to_scalar(nir);
> -         nir_validate_shader(nir);
> -      }
> +      NIR_PASS(nir_lower_vars_to_ssa, nir);
>
> -      progress |= nir_copy_prop(nir);
> -      nir_validate_shader(nir);
> +      if (is_scalar)
> +         NIR_PASS(nir_lower_alu_to_scalar, nir);
>
> -      if (is_scalar) {
> -         nir_lower_phis_to_scalar(nir);
> -         nir_validate_shader(nir);
> -      }
> +      progress |= NIR_PASS_PROGRESS(nir_copy_prop, nir);
> +
> +      if (is_scalar)
> +         NIR_PASS(nir_lower_phis_to_scalar, nir);
>
> -      progress |= nir_copy_prop(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_dce(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_cse(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_peephole_select(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_algebraic(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_constant_folding(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_dead_cf(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_remove_phis(nir);
> -      nir_validate_shader(nir);
> -      progress |= nir_opt_undef(nir);
> -      nir_validate_shader(nir);
> +      progress |= NIR_PASS_PROGRESS(nir_copy_prop, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_dce, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_cse, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_peephole_select, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_algebraic, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_constant_folding, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_dead_cf, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_remove_phis, nir);
> +      progress |= NIR_PASS_PROGRESS(nir_opt_undef, nir);
>     } while (progress);
> +   return nir;
>  }
>
>  nir_shader *
> @@ -204,75 +191,52 @@ brw_create_nir(struct brw_context *brw,
>     }
>     nir_validate_shader(nir);
>
> -   if (stage == MESA_SHADER_GEOMETRY) {
> -      nir_lower_gs_intrinsics(nir);
> -      nir_validate_shader(nir);
> -   }
> +   if (stage == MESA_SHADER_GEOMETRY)
> +      NIR_PASS(nir_lower_gs_intrinsics, nir);
>
> -   nir_lower_global_vars_to_local(nir);
> -   nir_validate_shader(nir);
> -
> -   nir_lower_tex(nir, &tex_options);
> -   nir_validate_shader(nir);
> -
> -   nir_normalize_cubemap_coords(nir);
> -   nir_validate_shader(nir);
> -
> -   nir_split_var_copies(nir);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_lower_global_vars_to_local, nir);
> +   NIR_PASS(nir_lower_tex, nir, &tex_options);
> +   NIR_PASS(nir_normalize_cubemap_coords, nir);
> +   NIR_PASS(nir_split_var_copies, nir);
>
> -   nir_optimize(nir, is_scalar);
> +   nir = nir_optimize(nir, is_scalar);
>
>     /* Lower a bunch of stuff */
> -   nir_lower_var_copies(nir);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_lower_var_copies, nir);
>
>     /* Get rid of split copies */
> -   nir_optimize(nir, is_scalar);
> +   nir = nir_optimize(nir, is_scalar);
>
>     brw_nir_lower_inputs(nir, is_scalar);
>     brw_nir_lower_outputs(nir, is_scalar);
>     nir_assign_var_locations(&nir->uniforms,
>                              &nir->num_uniforms,
>                              is_scalar ? type_size_scalar : type_size_vec4);
> -   nir_lower_io(nir, nir_var_all,
> +   NIR_PASS(nir_lower_io, nir, nir_var_all,
>                  is_scalar ? type_size_scalar : type_size_vec4);
> -   nir_validate_shader(nir);
> -
> -   nir_remove_dead_variables(nir);
> -   nir_validate_shader(nir);
>
> -   if (shader_prog) {
> -      nir_lower_samplers(nir, shader_prog);
> -      nir_validate_shader(nir);
> -   }
> +   NIR_PASS(nir_remove_dead_variables, nir);
>
> -   nir_lower_system_values(nir);
> -   nir_validate_shader(nir);
> +   if (shader_prog)
> +      NIR_PASS(nir_lower_samplers, nir, shader_prog);
>
> -   nir_lower_atomics(nir);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_lower_system_values, nir);
> +   NIR_PASS(nir_lower_atomics, nir);
>
> -   nir_optimize(nir, is_scalar);
> +   nir = nir_optimize(nir, is_scalar);
>
>     if (brw->gen >= 6) {
>        /* Try and fuse multiply-adds */
> -      nir_opt_peephole_ffma(nir);
> -      nir_validate_shader(nir);
> +      NIR_PASS(nir_opt_peephole_ffma, nir);
>     }
>
> -   nir_opt_algebraic_late(nir);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_opt_algebraic_late, nir);
>
> -   nir_lower_locals_to_regs(nir);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_lower_locals_to_regs, nir);
>
> -   nir_lower_to_source_mods(nir);
> -   nir_validate_shader(nir);
> -   nir_copy_prop(nir);
> -   nir_validate_shader(nir);
> -   nir_opt_dce(nir);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_lower_to_source_mods, nir);
> +   NIR_PASS(nir_copy_prop, nir);
> +   NIR_PASS(nir_opt_dce, nir);
>
>     if (unlikely(debug_enabled)) {
>        /* Re-index SSA defs so we print more sensible numbers. */
> @@ -286,15 +250,11 @@ brw_create_nir(struct brw_context *brw,
>        nir_print_shader(nir, stderr);
>     }
>
> -   nir_convert_from_ssa(nir, true);
> -   nir_validate_shader(nir);
> +   NIR_PASS(nir_convert_from_ssa, nir, true);
>
>     if (!is_scalar) {
> -      nir_move_vec_src_uses_to_dest(nir);
> -      nir_validate_shader(nir);
> -
> -      nir_lower_vec_to_movs(nir);
> -      nir_validate_shader(nir);
> +      NIR_PASS(nir_move_vec_src_uses_to_dest, nir);
> +      NIR_PASS(nir_lower_vec_to_movs, nir);
>     }
>
>     /* This is the last pass we run before we start emitting stuff.  It
> --
> 2.5.0
>


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