[Mesa-dev] [PATCH v3 (part2) 10/56] glsl: Lower unsized array's length calculation expression

Thomas Helland thomashelland90 at gmail.com
Tue Jul 14 02:05:34 PDT 2015


2015-07-14 9:46 GMT+02:00 Iago Toral Quiroga <itoral at igalia.com>:
> From: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
>
> Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
> ---
>  src/glsl/lower_ubo_reference.cpp | 179 +++++++++++++++++++++++++++++++++++++++

^ This is 80 characters wide in this case(for reference), so we're blowing
the 80-character width limit by quite a lot in the upper third part of
the patch.
It seems kinda tricky to split some of the cases to shorter widths though,
so I don't know if we want to care. Just thought I'd point it out in case it
was a pure oversight and not intentional =)

-Thomas

>  1 file changed, 179 insertions(+)
>
> diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp
> index 8b08107..9d0a796 100644
> --- a/src/glsl/lower_ubo_reference.cpp
> +++ b/src/glsl/lower_ubo_reference.cpp
> @@ -166,6 +166,16 @@ public:
>                      bool row_major, int matrix_columns,
>                      unsigned write_mask);
>
> +   ir_visitor_status visit_enter(class ir_expression *);
> +   void check_ssbo_unsized_array_length_expression(class ir_expression *);
> +   void check_ssbo_unsized_array_length_assignment(ir_assignment *ir);
> +
> +   ir_expression *process_ssbo_unsized_array_length(ir_rvalue **, ir_dereference *, ir_variable *);
> +   ir_expression *emit_ssbo_unsized_array_length(ir_variable *base_offset,
> +                                                 unsigned int deref_offset,
> +                                                 unsigned int unsized_array_stride);
> +   unsigned calculate_unsized_array_stride(ir_dereference *deref);
> +
>     void *mem_ctx;
>     struct gl_shader *shader;
>     struct gl_uniform_buffer_variable *ubo_var;
> @@ -738,6 +748,174 @@ lower_ubo_reference_visitor::write_to_memory(ir_dereference *deref,
>                 row_major, matrix_columns, write_mask);
>  }
>
> +ir_visitor_status
> +lower_ubo_reference_visitor::visit_enter(ir_expression *ir)
> +{
> +   check_ssbo_unsized_array_length_expression(ir);
> +   return rvalue_visit(ir);
> +}
> +
> +void
> +lower_ubo_reference_visitor::check_ssbo_unsized_array_length_expression(ir_expression *former_ir)
> +{
> +   if (former_ir->operation == ir_expression_operation(ir_unop_ssbo_unsized_array_length)) {
> +         /* Don't replace this unop if it is found alone. It is going to be
> +          * removed by the optimization passes or replaced if it is part of
> +          * an ir_assignment or another ir_expression.
> +          */
> +         return;
> +   }
> +
> +   for (unsigned i = 0; i < 4; i++) {
> +      if (!former_ir->operands[i] || former_ir->operands[i]->ir_type != ir_type_expression)
> +         continue;
> +      ir_expression *ir = (ir_expression *) former_ir->operands[i];
> +      if (ir->operation == ir_expression_operation(ir_unop_ssbo_unsized_array_length)) {
> +         ir_rvalue *rvalue = ir->operands[0]->as_rvalue();
> +         if (!rvalue || !rvalue->type->is_array() || !rvalue->type->is_unsized_array())
> +            return;
> +
> +         ir_dereference *deref = ir->operands[0]->as_dereference();
> +         if (!deref)
> +            return;
> +
> +         ir_variable *var = ir->operands[0]->variable_referenced();
> +         if (!var || !var->is_in_shader_storage_block())
> +            return;
> +         /* Now replace the unop instruction for the triop */
> +         ir_expression *temp = process_ssbo_unsized_array_length(&rvalue, deref, var);
> +         delete ir;
> +         former_ir->operands[i] = temp;
> +      }
> +   }
> +}
> +
> +void
> +lower_ubo_reference_visitor::check_ssbo_unsized_array_length_assignment(ir_assignment *ir)
> +{
> +   if (!ir->rhs || ir->rhs->ir_type != ir_type_expression)
> +      return;
> +
> +   ir_expression *expr = (ir_expression *) ir->rhs;
> +   if (expr->operation == ir_expression_operation(ir_unop_ssbo_unsized_array_length)) {
> +      ir_rvalue *rvalue = expr->operands[0]->as_rvalue();
> +      if (!rvalue || !rvalue->type->is_array() || !rvalue->type->is_unsized_array())
> +         return;
> +
> +      ir_dereference *deref = expr->operands[0]->as_dereference();
> +      if (!deref)
> +         return;
> +
> +      ir_variable *var = expr->operands[0]->variable_referenced();
> +      if (!var || !var->is_in_shader_storage_block())
> +         return;
> +      /* Now replace the unop instruction for the binop */
> +      ir_expression *temp = process_ssbo_unsized_array_length(&rvalue, deref, var);
> +      delete expr;
> +      ir->rhs = temp;
> +      return;
> +   }
> +   return;
> +}
> +
> +ir_expression *
> +lower_ubo_reference_visitor::emit_ssbo_unsized_array_length(ir_variable *base_offset,
> +                                                            unsigned int deref_offset,
> +                                                            unsigned int unsized_array_stride)
> +{
> +   ir_rvalue *offset =
> +      add(base_offset, new(mem_ctx) ir_constant(deref_offset));
> +   ir_rvalue *stride = new(mem_ctx) ir_constant(unsized_array_stride);
> +   ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL);
> +   return new(mem_ctx) ir_expression(ir_triop_ssbo_unsized_array_length,
> +                                     glsl_type::int_type, block_ref, offset, stride);
> +}
> +
> +unsigned
> +lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *deref)
> +{
> +   unsigned array_stride = 0;
> +
> +   switch (deref->ir_type) {
> +   case ir_type_dereference_variable:
> +   {
> +      ir_dereference_variable *deref_var = (ir_dereference_variable *)deref;
> +      const struct glsl_type *unsized_array_type = NULL;
> +      /* An unsized array can be sized by other lowering passes, so pick
> +       * the first field of the array which has the data type of the unsized
> +       * array.
> +       */
> +      unsized_array_type = deref_var->var->type->fields.array;
> +
> +      /* Whether or not the field is row-major (because it might be a
> +      * bvec2 or something) does not affect the array itself. We need
> +      * to know whether an array element in its entirety is row-major.
> +      */
> +      const bool array_row_major =
> +         is_dereferenced_thing_row_major(deref_var);
> +
> +      array_stride = unsized_array_type->std140_size(array_row_major);
> +      array_stride = glsl_align(array_stride, 16);
> +      break;
> +   }
> +   case ir_type_dereference_record:
> +   {
> +      ir_dereference_record *deref_record = (ir_dereference_record *) deref;
> +      const struct glsl_type *deref_record_type =
> +         deref_record->record->as_dereference()->type;
> +      unsigned record_length = deref_record_type->length;
> +      /* Unsized array is always the last element of the interface */
> +      const struct glsl_type *unsized_array_type =
> +         deref_record_type->fields.structure[record_length - 1].type->fields.array;
> +
> +      const bool array_row_major =
> +         is_dereferenced_thing_row_major(deref_record);
> +      array_stride = unsized_array_type->std140_size(array_row_major);
> +      array_stride = glsl_align(array_stride, 16);
> +      break;
> +   }
> +   default:
> +      assert(!"Not reached");
> +   }
> +   return array_stride;
> +}
> +
> +ir_expression *
> +lower_ubo_reference_visitor::process_ssbo_unsized_array_length(ir_rvalue **rvalue,
> +                                                               ir_dereference *deref,
> +                                                               ir_variable *var)
> +{
> +   mem_ctx = ralloc_parent(*rvalue);
> +
> +   ir_rvalue *offset = NULL;
> +   unsigned const_offset;
> +   bool row_major;
> +   int matrix_columns;
> +   unsigned unsized_array_stride = calculate_unsized_array_stride(deref);
> +
> +   /* Compute the offset to the start if the dereference as well as other
> +    * information we need to configure the length
> +    */
> +   setup_for_load_or_store(var, deref,
> +                           &offset, &const_offset,
> +                           &row_major, &matrix_columns);
> +
> +   /* Now that we've calculated the offset to the start of the
> +    * dereference, emit writes from the temporary to memory
> +    */
> +   ir_variable *write_offset = new(mem_ctx) ir_variable(glsl_type::uint_type,
> +                                                        "ssbo_length_temp_offset",
> +                                                        ir_var_temporary);
> +   base_ir->insert_after(write_offset);
> +   base_ir->insert_after(assign(write_offset, offset));
> +
> +   ir_expression *new_ssbo = emit_ssbo_unsized_array_length(write_offset,
> +                                                            const_offset,
> +                                                            unsized_array_stride);
> +
> +   return new_ssbo;
> +}
> +
>  void
>  lower_ubo_reference_visitor::check_for_ssbo_store(ir_assignment *ir)
>  {
> @@ -777,6 +955,7 @@ lower_ubo_reference_visitor::check_for_ssbo_store(ir_assignment *ir)
>  ir_visitor_status
>  lower_ubo_reference_visitor::visit_enter(ir_assignment *ir)
>  {
> +   check_ssbo_unsized_array_length_assignment(ir);
>     check_for_ssbo_store(ir);
>     return rvalue_visit(ir);
>  }
> --
> 1.9.1
>


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