[Mesa-dev] [PATCH V3 5/6] nir: support indirect indexing samplers in struct arrays

Timothy Arceri t_arceri at yahoo.com.au
Thu Sep 10 20:28:16 PDT 2015


On Fri, 2015-09-11 at 12:55 +1000, Timothy Arceri wrote:
> On Thu, 2015-09-10 at 18:04 -0700, Jason Ekstrand wrote:
> > On Tue, Sep 1, 2015 at 7:44 PM, Timothy Arceri <
> > t_arceri at yahoo.com.au
> > > wrote:
> > > As a bonus we get indirect support for arrays of arrays for free.
> > > 
> > > V3: Use nir_instr_rewrite_src() with empty src rather then
> > > clearing
> > > the use_link list directly for the old indirects as suggested by
> > > Jason
> > > 
> > > V2: Fixed validation error in debug build
> > > ---
> > >  src/glsl/nir/nir_lower_samplers.cpp | 169 ++++++++++++++++++++--
> > > --
> > > ------------
> > >  1 file changed, 95 insertions(+), 74 deletions(-)
> > > 
> > > diff --git a/src/glsl/nir/nir_lower_samplers.cpp
> > > b/src/glsl/nir/nir_lower_samplers.cpp
> > > index 9583b45..9736e0f 100644
> > > --- a/src/glsl/nir/nir_lower_samplers.cpp
> > > +++ b/src/glsl/nir/nir_lower_samplers.cpp
> > > @@ -24,6 +24,7 @@
> > >   */
> > > 
> > >  #include "nir.h"
> > > +#include "nir_builder.h"
> > >  #include "../program.h"
> > >  #include "program/hash_table.h"
> > >  #include "ir_uniform.h"
> > > @@ -35,89 +36,52 @@ extern "C" {
> > >  #include "program/program.h"
> > >  }
> > > 
> > > -static unsigned
> > > -get_sampler_index(const struct gl_shader_program
> > > *shader_program,
> > > -                  gl_shader_stage stage, const char *name)
> > > -{
> > > -   unsigned location;
> > > -   if (!shader_program->UniformHash->get(location, name)) {
> > > -      assert(!"failed to find sampler");
> > > -      return 0;
> > > -   }
> > > -
> > > -   if (!shader_program
> > > ->UniformStorage[location].sampler[stage].active) {
> > > -      assert(!"cannot return a sampler");
> > > -      return 0;
> > > -   }
> > > -
> > > -   return shader_program
> > > ->UniformStorage[location].sampler[stage].index;
> > > -}
> > > -
> > > +/* Calculate the sampler index based on array indicies and also
> > > + * calculate the base uniform location for struct members.
> > > + */
> > >  static void
> > > -lower_sampler(nir_tex_instr *instr, const struct
> > > gl_shader_program
> > > *shader_program,
> > > -              gl_shader_stage stage, void *mem_ctx)
> > > +calc_sampler_offsets(nir_deref *tail, nir_tex_instr *instr,
> > > +                     unsigned *array_elements, nir_src
> > > *indirect,
> > > +                     nir_builder *b, unsigned *location,
> > > +                     bool *found_indirect)
> > >  {
> > > -   if (instr->sampler == NULL)
> > > -      return;
> > > -
> > > -   /* Get the name and the offset */
> > > -   instr->sampler_index = 0;
> > > -   char *name = ralloc_strdup(mem_ctx, instr->sampler->var
> > > ->name);
> > > -
> > > -   for (nir_deref *deref = &instr->sampler->deref;
> > > -        deref->child; deref = deref->child) {
> > > -      switch (deref->child->deref_type) {
> > > +   if (tail->child != NULL) {
> > > +      switch (tail->child->deref_type) {
> > >        case nir_deref_type_array: {
> > > -         nir_deref_array *deref_array = nir_deref_as_array(deref
> > > ->child);
> > > +         nir_deref_array *deref_array = nir_deref_as_array(tail
> > > ->child);
> > > 
> > >           assert(deref_array->deref_array_type !=
> > > nir_deref_array_type_wildcard);
> > > 
> > > -         if (deref_array->deref.child) {
> > > -            ralloc_asprintf_append(&name, "[%u]",
> > > -               deref_array->deref_array_type ==
> > > nir_deref_array_type_direct ?
> > > -                  deref_array->base_offset : 0);
> > > -         } else {
> > > -            assert(deref->child->type->base_type ==
> > > GLSL_TYPE_SAMPLER);
> > > -            instr->sampler_index = deref_array->base_offset;
> > > -         }
> > > +         calc_sampler_offsets(tail->child, instr,
> > > array_elements,
> > > +                              indirect, b, location,
> > > found_indirect);
> > > +         instr->sampler_index += deref_array->base_offset *
> > > *array_elements;
> > > 
> > > -         /* XXX: We're assuming here that the indirect is the
> > > last
> > > array
> > > -          * thing we have.  This should be ok for now as we
> > > don't
> > > support
> > > -          * arrays_of_arrays yet.
> > > -          */
> > >           if (deref_array->deref_array_type ==
> > > nir_deref_array_type_indirect) {
> > > -            /* First, we have to resize the array of texture
> > > sources */
> > > -            nir_tex_src *new_srcs = rzalloc_array(instr,
> > > nir_tex_src,
> > > -                                                  instr
> > > ->num_srcs
> > > + 1);
> > > -
> > > -            for (unsigned i = 0; i < instr->num_srcs; i++) {
> > > -               new_srcs[i].src_type = instr->src[i].src_type;
> > > -               nir_instr_move_src(&instr->instr,
> > > &new_srcs[i].src,
> > > -                                  &instr->src[i].src);
> > > +            nir_ssa_def *mul =
> > > +               nir_imul(b, nir_imm_int(b, *array_elements),
> > > +                        nir_ssa_for_src(b, deref_array
> > > ->indirect,
> > > 1));
> > > +
> > > +            nir_instr_rewrite_src(&instr->instr, &deref_array
> > > ->indirect,
> > > +                                  NIR_SRC_INIT);
> > > +
> > > +            if (*found_indirect) {
> > > +               indirect->ssa =
> > > +                  nir_iadd(b, nir_ssa_for_src(b, *indirect, 1),
> > > mul);
> > > +            } else {
> > > +               *indirect = nir_src_for_ssa(mul);
> > > +               *found_indirect = true;
> > >              }
> > > -
> > > -            ralloc_free(instr->src);
> > > -            instr->src = new_srcs;
> > > -
> > > -            /* Now we can go ahead and move the source over to
> > > being a
> > > -             * first-class texture source.
> > > -             */
> > > -            instr->src[instr->num_srcs].src_type =
> > > nir_tex_src_sampler_offset;
> > > -            instr->num_srcs++;
> > > -            nir_instr_move_src(&instr->instr,
> > > -                               &instr->src[instr->num_srcs -
> > > 1].src,
> > > -                               &deref_array->indirect);
> > > -
> > > -            instr->sampler_array_size = glsl_get_length(deref
> > > ->type);
> > >           }
> > > -         break;
> > > +
> > > +         *array_elements *= glsl_get_length(tail->type);
> > > +          break;
> > >        }
> > > 
> > >        case nir_deref_type_struct: {
> > > -         nir_deref_struct *deref_struct =
> > > nir_deref_as_struct(deref->child);
> > > -         const char *field = glsl_get_struct_elem_name(deref
> > > ->type,
> > > -                                                      
> > >  deref_struct->index);
> > > -         ralloc_asprintf_append(&name, ".%s", field);
> > > +         nir_deref_struct *deref_struct =
> > > nir_deref_as_struct(tail
> > > ->child);
> > > +         *location += deref_struct->index;
> > 
> > I finally got around to looking at this patch again and most of it
> > seems fine except for this line.  I don't think you can just
> > increment
> > location by deref_struct->index.  I think you need to add up all of
> > the array sizes of all of the previous members.  (Yeah, that's
> > gross
> > but I'm not thinking of anything better off-hand).
> 
> I think I might have to do this for AoA but single dimension arrays
> are
> all stored at the same location so I think this is ok as is for now,
> unless I'm missing something?

Actually it looks like this is whats causing most of the regressions in
the deqp test. I need to add up all the member elements of previous
nested structs.


> 
> 
> > 
> > > +         calc_sampler_offsets(tail->child, instr,
> > > array_elements,
> > > +                              indirect, b, location,
> > > found_indirect);
> > >           break;
> > >        }
> > > 
> > > @@ -125,15 +89,72 @@ lower_sampler(nir_tex_instr *instr, const
> > > struct gl_shader_program *shader_progr
> > >           unreachable("Invalid deref type");
> > >           break;
> > >        }
> > > +   } else {
> > > +      return;
> > > +   }
> > > +}
> > > +
> > > +static void
> > > +lower_sampler(nir_tex_instr *instr, const struct
> > > gl_shader_program
> > > *shader_program,
> > > +              gl_shader_stage stage, nir_builder *builder)
> > > +{
> > > +   if (instr->sampler == NULL)
> > > +      return;
> > > +
> > > +   instr->sampler_index = 0;
> > > +   unsigned location = instr->sampler->var->data.location;
> > > +
> > > +   if (instr->sampler->deref.child) {
> > > +      unsigned array_elements = 1;
> > > +      nir_src indirect;
> > > +      bool found_indirect = false;
> > 
> > I may have made this comment before, but wouldn't it be easier to
> > just
> > have "indirect" be a nir_ssa_def pointer?  Then you wouldn't need
> > to
> > also have a boolean (NULL == no indirect) and you could completely
> > side-step any nir_src copying issues.
> 
> I think I had to code like this at one point but changed it (no idea
> why). I'll give it another go. 
> 
> Thanks for looking over all these :) I'm just trying to resolve some
> regressions with the deqp test suite then I'll send out a new version
> updated with your feedback.
> 
> 
> > 
> > --Jason
> > 
> > > +
> > > +      builder->cursor = nir_before_instr(&instr->instr);
> > > +      calc_sampler_offsets(&instr->sampler->deref, instr,
> > > +                           &array_elements, &indirect, builder,
> > > +                           &location, &found_indirect);
> > > +
> > > +      if (found_indirect) {
> > > +         /* First, we have to resize the array of texture
> > > sources
> > > */
> > > +         nir_tex_src *new_srcs = rzalloc_array(instr,
> > > nir_tex_src,
> > > +                                               instr->num_srcs +
> > > 1);
> > > +
> > > +         for (unsigned i = 0; i < instr->num_srcs; i++) {
> > > +            new_srcs[i].src_type = instr->src[i].src_type;
> > > +            nir_instr_move_src(&instr->instr, &new_srcs[i].src,
> > > +                               &instr->src[i].src);
> > > +         }
> > > +
> > > +         ralloc_free(instr->src);
> > > +         instr->src = new_srcs;
> > > +
> > > +         /* Now we can go ahead and move the source over to
> > > being
> > > a
> > > +          * first-class texture source.
> > > +          */
> > > +         instr->src[instr->num_srcs].src_type =
> > > nir_tex_src_sampler_offset;
> > > +         instr->num_srcs++;
> > > +         nir_instr_rewrite_src(&instr->instr,
> > > +                               &instr->src[instr->num_srcs -
> > > 1].src,
> > > +                               indirect);
> > > +
> > > +         instr->sampler_array_size = array_elements;
> > > +      }
> > > +   }
> > > +
> > > +   if (location > shader_program->NumUniformStorage - 1 ||
> > > +       !shader_program
> > > ->UniformStorage[location].sampler[stage].active) {
> > > +      assert(!"cannot return a sampler");
> > > +      return;
> > >     }
> > > 
> > > -   instr->sampler_index += get_sampler_index(shader_program,
> > > stage, name);
> > > +   instr->sampler_index +=
> > > +      shader_program
> > > ->UniformStorage[location].sampler[stage].index;
> > > 
> > >     instr->sampler = NULL;
> > >  }
> > > 
> > >  typedef struct {
> > > -   void *mem_ctx;
> > > +   nir_builder builder;
> > >     const struct gl_shader_program *shader_program;
> > >     gl_shader_stage stage;
> > >  } lower_state;
> > > @@ -147,7 +168,7 @@ lower_block_cb(nir_block *block, void
> > > *_state)
> > >        if (instr->type == nir_instr_type_tex) {
> > >           nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
> > >           lower_sampler(tex_instr, state->shader_program, state
> > > ->stage,
> > > -                       state->mem_ctx);
> > > +                       &state->builder);
> > >        }
> > >     }
> > > 
> > > @@ -160,7 +181,7 @@ lower_impl(nir_function_impl *impl, const
> > > struct gl_shader_program *shader_progr
> > >  {
> > >     lower_state state;
> > > 
> > > -   state.mem_ctx = ralloc_parent(impl);
> > > +   nir_builder_init(&state.builder, impl);
> > >     state.shader_program = shader_program;
> > >     state.stage = stage;
> > > 
> > > --
> > > 2.4.3
> > > 
> > > _______________________________________________
> > > mesa-dev mailing list
> > > mesa-dev at lists.freedesktop.org
> > > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> _______________________________________________
> mesa-dev mailing list
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