[Mesa-dev] [PATCH 1/4] st/mesa: handle indirect samplers in arrays/structs properly (v3)

Timothy Arceri t_arceri at yahoo.com.au
Fri Feb 5 23:31:39 UTC 2016


On Fri, 2016-02-05 at 13:40 +1000, Dave Airlie wrote:
> From: Dave Airlie <airlied at redhat.com>
> 
> The state tracker never handled this properly, and it finally
> annoyed me for the second time so I decided to fix it properly.
> 
> This is inspired by the NIR sampler lowering code and I only realised
> NIR seems to do its deref ordering different to GLSL at the last
> minute, once I got that things got much easier.
> 
> it fixes a bunch of tests in
> tests/spec/arb_gpu_shader5/execution/sampler_array_indexing/
> 
> v2: fix AoA tests when forced on.
> I was right I didn't need all that code, fixing the AoA code
> meant cleaning up a chunk of code I didn't like in the array
> handling.
> 
> v3: start generalising the code a bit more for atomics.
> 
> Signed-off-by: Dave Airlie <airlied at redhat.com>
> ---
>  src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 145
> +++++++++++++++++++++++++----
>  1 file changed, 127 insertions(+), 18 deletions(-)
> 
> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> index b8182de..c36edc9 100644
> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> @@ -40,7 +40,6 @@
>  #include "main/uniforms.h"
>  #include "main/shaderapi.h"
>  #include "program/prog_instruction.h"
> -#include "program/sampler.h"
>  
>  #include "pipe/p_context.h"
>  #include "pipe/p_screen.h"
> @@ -257,6 +256,7 @@ public:
>     GLboolean cond_update;
>     bool saturate;
>     st_src_reg sampler; /**< sampler register */
> +   int sampler_base;
>     int sampler_array_size; /**< 1-based size of sampler array, 1 if
> not array */
>     int tex_target; /**< One of TEXTURE_*_INDEX */
>     glsl_base_type tex_type;
> @@ -502,6 +502,18 @@ public:
>  
>     void emit_arl(ir_instruction *ir, st_dst_reg dst, st_src_reg
> src0);
>  
> +   void get_deref_offsets(ir_dereference *ir,
> +                          unsigned *array_size,
> +                          unsigned *base,
> +                          unsigned *index,
> +                          st_src_reg *reladdr);
> +  void calc_deref_offsets(ir_dereference *head,
> +                          ir_dereference *tail,
> +                          unsigned *array_elements,
> +                          unsigned *index,
> +                          st_src_reg *indirect,
> +                          unsigned *location);
> +
>     bool try_emit_mad(ir_expression *ir,
>                int mul_operand);
>     bool try_emit_mad_for_and_not(ir_expression *ir,
> @@ -3436,18 +3448,118 @@ glsl_to_tgsi_visitor::visit(ir_call *ir)
>     this->result = entry->return_reg;
>  }
>  
> +static unsigned
> +glsl_get_length(const struct glsl_type *type)
> +{
> +   return type->is_matrix() ? type->matrix_columns : type->length;
> +}

This isn't needed the type should always be an array unless something
has gone horribly wrong. Nir uses this because it needs a wrapper for
cpp. I don't think the matrix stuff was even there when I added nir
support originally.

> +
> +void
> +glsl_to_tgsi_visitor::calc_deref_offsets(ir_dereference *head,
> +                                         ir_dereference *tail,
> +                                         unsigned *array_elements,
> +                                         unsigned *index,
> +                                         st_src_reg *indirect,
> +                                         unsigned *location)
> +{
> +   switch (tail->ir_type) {
> +   case ir_type_dereference_record: {
> +      ir_dereference_record *deref_record = tail-
> >as_dereference_record();
> +      const glsl_type *struct_type = deref_record->record->type;
> +      int tmp = 0;
> +      unsigned i;
> +
> +      calc_deref_offsets(head, deref_record->record-
> >as_dereference(), array_elements, index, indirect, location);
> +
> +      for (i = 0; i < struct_type->length; i++) {
> +         if (strcmp(struct_type->fields.structure[i].name,
> deref_record->field) == 0)
> +            break;
> +      }

Rather than doing this you can used do:

i = deref_record->record->type->field_index(deref_record->field);

> +      if (i < struct_type->length)
> +         tmp = struct_type->record_location_offset(i);
> +
> +      *location += tmp;

As pointed out on irc location needs to be initialised to the base
struct location currently this is always starting at 0. Solution
further down.

> +      break;
> +   }
> +
> +   case ir_type_dereference_array: {
> +      ir_dereference_array *deref_arr = tail-
> >as_dereference_array();
> +      ir_constant *array_index = deref_arr->array_index-
> >constant_expression_value();
> +
> +      if (deref_arr->array->ir_type == ir_type_dereference_variable
> && head == tail) {
> +         ir_dereference_variable *deref_var = deref_arr->array-
> >as_dereference_variable();
> +         *location += deref_var->var->data.location;
> +      }
> +
> +      if (!array_index) {
> +         st_src_reg temp_reg;
> +         st_dst_reg temp_dst;
> +
> +         temp_reg = get_temp(glsl_type::uint_type);
> +         temp_dst = st_dst_reg(temp_reg);
> +         temp_dst.writemask = 1;
> +
> +         deref_arr->array_index->accept(this);
> +         emit_asm(NULL, TGSI_OPCODE_MUL, temp_dst, this->result,
> st_src_reg_for_int(*array_elements));
> +
> +         if (indirect->file == PROGRAM_UNDEFINED)
> +            *indirect = temp_reg;
> +         else {
> +            temp_dst = st_dst_reg(*indirect);
> +            temp_dst.writemask = 1;
> +            emit_asm(NULL, TGSI_OPCODE_ADD, temp_dst, *indirect,
> temp_reg);
> +         }
> +      } else
> +         *index += array_index->value.u[0] * *array_elements;
> +
> +      *array_elements *= glsl_get_length(deref_arr->array->type);

Just deref_arr->array->type->length will do as pointed out above.

> +
> +      calc_deref_offsets(head, deref_arr->array->as_dereference(),
> array_elements, index, indirect, location);
> +      break;
> +   }
> +   case ir_type_dereference_variable: {
> +      if (head == tail) {
> +         ir_dereference_variable *deref_var = tail-
> >as_dereference_variable();
> +         *location = deref_var->var->data.location;
> +      }

You don't really need this or any of the other head==tail stuff since
as pointed out above you need to initalise location with the base
location so you can do this outside the first calc_deref_offsets() then
you can just make this return or add:

   if (deref->ir_type == ir_type_dereference_variable)
      return;

I can't say I've taken time to fully understand the tgsi specifics here but I think I've looked at it enough to give:

Reviewed-by: Timothy Arceri <timothy.arceri at collabora.com> to patches 1, 2 and 4 if you make the suggested changes (and it still works of course).

I'll leave you and Ilia to figure out patch 3 :)

I'm also about to send a couple of follow up patches to tidy up the remaining ir_to_mesa stuff. I based it off this patch :P I think I did it once before and failed. Now that I think of it I was probably trying to do the deref in the NIR order rather than GLSL IR order.


> +      break;
> +   }
> +   default:
> +      break;
> +   }
> +}
> +
> +void
> +glsl_to_tgsi_visitor::get_deref_offsets(ir_dereference *ir,
> +                                        unsigned *array_size,
> +                                        unsigned *base,
> +                                        unsigned *index,
> +                                        st_src_reg *reladdr)
> +{
> +   GLuint shader = _mesa_program_enum_to_shader_stage(this->prog-
> >Target);
> +   unsigned location = 0;
> +
> +   memset(reladdr, 0, sizeof(*reladdr));
> +   reladdr->file = PROGRAM_UNDEFINED;
> +
> +   *array_size = 1;
> +   calc_deref_offsets(ir, ir, array_size, index, reladdr,
> &location);
> +
> +   *base = this->shader_program-
> >UniformStorage[location].opaque[shader].index;
> +   *index += *base;
> +}
> +
>  void
>  glsl_to_tgsi_visitor::visit(ir_texture *ir)
>  {
>     st_src_reg result_src, coord, cube_sc, lod_info, projector, dx,
> dy;
>     st_src_reg offset[MAX_GLSL_TEXTURE_OFFSET], sample_index,
> component;
> -   st_src_reg levels_src;
> +   st_src_reg levels_src, reladdr;
>     st_dst_reg result_dst, coord_dst, cube_sc_dst;
>     glsl_to_tgsi_instruction *inst = NULL;
>     unsigned opcode = TGSI_OPCODE_NOP;
>     const glsl_type *sampler_type = ir->sampler->type;
> -   ir_rvalue *sampler_index =
> -      _mesa_get_sampler_array_nonconst_index(ir->sampler);
> +   unsigned sampler_array_size = 1, sampler_index = 0, sampler_base
> = 0;
>     bool is_cube_array = false;
>     unsigned i;
>  
> @@ -3669,10 +3781,10 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
>        coord_dst.writemask = WRITEMASK_XYZW;
>     }
>  
> -   if (sampler_index) {
> -      sampler_index->accept(this);
> -      emit_arl(ir, sampler_reladdr, this->result);
> -   }
> +   get_deref_offsets(ir->sampler, &sampler_array_size,
> &sampler_base,
> +                     &sampler_index, &reladdr);
> +   if (reladdr.file != PROGRAM_UNDEFINED)
> +      emit_arl(ir, sampler_reladdr, reladdr);
>  
>     if (opcode == TGSI_OPCODE_TXD)
>        inst = emit_asm(ir, opcode, result_dst, coord, dx, dy);
> @@ -3705,16 +3817,13 @@ glsl_to_tgsi_visitor::visit(ir_texture *ir)
>     if (ir->shadow_comparitor)
>        inst->tex_shadow = GL_TRUE;
>  
> -   inst->sampler.index = _mesa_get_sampler_uniform_value(ir-
> >sampler,
> -                                                         this-
> >shader_program,
> -                                                         this-
> >prog);
> -   if (sampler_index) {
> +   inst->sampler.index = sampler_index;
> +   inst->sampler_array_size = sampler_array_size;
> +   inst->sampler_base = sampler_base;
> +
> +   if (reladdr.file != PROGRAM_UNDEFINED) {
>        inst->sampler.reladdr = ralloc(mem_ctx, st_src_reg);
> -      memcpy(inst->sampler.reladdr, &sampler_reladdr,
> sizeof(sampler_reladdr));
> -      inst->sampler_array_size =
> -         ir->sampler->as_dereference_array()->array->type-
> >array_size();
> -   } else {
> -      inst->sampler_array_size = 1;
> +      memcpy(inst->sampler.reladdr, &reladdr, sizeof(reladdr));
>     }
>  
>     if (ir->offset) {
> @@ -3915,7 +4024,7 @@ count_resources(glsl_to_tgsi_visitor *v,
> gl_program *prog)
>     foreach_in_list(glsl_to_tgsi_instruction, inst, &v->instructions) 
> {
>        if (inst->info->is_tex) {
>           for (int i = 0; i < inst->sampler_array_size; i++) {
> -            unsigned idx = inst->sampler.index + i;
> +            unsigned idx = inst->sampler_base + i;
>              v->samplers_used |= 1 << idx;
>  
>              debug_assert(idx < (int)ARRAY_SIZE(v->sampler_types));


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