[Mesa-dev] [PATCH v5 28/70] glsl: add std430 interface packing support to ssbo related operations

Jordan Justen jordan.l.justen at intel.com
Wed Sep 16 11:48:04 PDT 2015


On 2015-09-16 01:01:30, Samuel Iglesias Gonsálvez wrote:
> 
> 
> On 16/09/15 09:46, Jordan Justen wrote:
> > On 2015-09-10 06:35:44, Iago Toral Quiroga wrote:
> >> From: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
> >>
> >> v2:
> >> - Get interface packing information from interface's type, not the variable type.
> >> - Simplify is_std430 condition in emit_access() for readability (Jordan)
> >> - Add a commment explaing why array of three-component vector case is different
> > 
> > Lines a bit long.
> > 
> 
> OK, I will fix it.
> 
> >>   in std430 than the rest of cases.
> >> - Add calls to std430_array_stride().
> >>
> >> Signed-off-by: Samuel Iglesias Gonsalvez <siglesias at igalia.com>
> >> ---
> >>  src/glsl/lower_ubo_reference.cpp | 102 ++++++++++++++++++++++++++++++---------
> >>  1 file changed, 78 insertions(+), 24 deletions(-)
> >>
> >> diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp
> >> index 8694383..7e45a26 100644
> >> --- a/src/glsl/lower_ubo_reference.cpp
> >> +++ b/src/glsl/lower_ubo_reference.cpp
> >> @@ -147,7 +147,8 @@ public:
> >>                                  ir_rvalue **offset,
> >>                                  unsigned *const_offset,
> >>                                  bool *row_major,
> >> -                                int *matrix_columns);
> >> +                                int *matrix_columns,
> >> +                                unsigned packing);
> >>     ir_expression *ubo_load(const struct glsl_type *type,
> >>                            ir_rvalue *offset);
> >>     ir_call *ssbo_load(const struct glsl_type *type,
> >> @@ -164,7 +165,7 @@ public:
> >>     void emit_access(bool is_write, ir_dereference *deref,
> >>                      ir_variable *base_offset, unsigned int deref_offset,
> >>                      bool row_major, int matrix_columns,
> >> -                    unsigned write_mask);
> >> +                    bool is_std430, unsigned write_mask);
> >>  
> >>     ir_visitor_status visit_enter(class ir_expression *);
> >>     ir_expression *calculate_ssbo_unsized_array_length(ir_expression *expr);
> >> @@ -176,7 +177,8 @@ public:
> >>                                                      ir_variable *);
> >>     ir_expression *emit_ssbo_get_buffer_size();
> >>  
> >> -   unsigned calculate_unsized_array_stride(ir_dereference *deref);
> >> +   unsigned calculate_unsized_array_stride(ir_dereference *deref,
> >> +                                           unsigned packing);
> >>  
> >>     void *mem_ctx;
> >>     struct gl_shader *shader;
> >> @@ -257,7 +259,8 @@ lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var,
> >>                                                       ir_rvalue **offset,
> >>                                                       unsigned *const_offset,
> >>                                                       bool *row_major,
> >> -                                                     int *matrix_columns)
> >> +                                                     int *matrix_columns,
> >> +                                                     unsigned packing)
> >>  {
> >>     /* Determine the name of the interface block */
> >>     ir_rvalue *nonconst_block_index;
> >> @@ -343,8 +346,15 @@ lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var,
> >>              const bool array_row_major =
> >>                 is_dereferenced_thing_row_major(deref_array);
> >>  
> >> -            array_stride = deref_array->type->std140_size(array_row_major);
> >> -            array_stride = glsl_align(array_stride, 16);
> >> +            /* The array type will give the correct interface packing
> >> +             * information
> >> +             */
> >> +            if (packing == GLSL_INTERFACE_PACKING_STD430) {
> >> +               array_stride = deref_array->type->std430_array_stride(array_row_major);
> >> +            } else {
> >> +               array_stride = deref_array->type->std140_size(array_row_major);
> >> +               array_stride = glsl_align(array_stride, 16);
> >> +            }
> >>           }
> >>  
> >>           ir_rvalue *array_index = deref_array->array_index;
> >> @@ -380,7 +390,12 @@ lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var,
> >>  
> >>              ralloc_free(field_deref);
> >>  
> >> -            unsigned field_align = type->std140_base_alignment(field_row_major);
> >> +            unsigned field_align = 0;
> >> +
> >> +            if (packing == GLSL_INTERFACE_PACKING_STD430)
> >> +               field_align = type->std430_base_alignment(field_row_major);
> >> +            else
> >> +               field_align = type->std140_base_alignment(field_row_major);
> >>  
> >>              intra_struct_offset = glsl_align(intra_struct_offset, field_align);
> >>  
> >> @@ -388,7 +403,10 @@ lower_ubo_reference_visitor::setup_for_load_or_store(ir_variable *var,
> >>                         deref_record->field) == 0)
> >>                 break;
> >>  
> >> -            intra_struct_offset += type->std140_size(field_row_major);
> >> +            if (packing == GLSL_INTERFACE_PACKING_STD430)
> >> +               intra_struct_offset += type->std430_size(field_row_major);
> >> +            else
> >> +               intra_struct_offset += type->std140_size(field_row_major);
> >>  
> >>              /* If the field just examined was itself a structure, apply rule
> >>               * #9:
> >> @@ -437,13 +455,15 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
> >>     unsigned const_offset;
> >>     bool row_major;
> >>     int matrix_columns;
> >> +   unsigned packing = var->get_interface_type()->interface_packing;
> >>  
> >>     /* Compute the offset to the start if the dereference as well as other
> >>      * information we need to configure the write
> >>      */
> >>     setup_for_load_or_store(var, deref,
> >>                             &offset, &const_offset,
> >> -                           &row_major, &matrix_columns);
> >> +                           &row_major, &matrix_columns,
> >> +                           packing);
> >>     assert(offset);
> >>  
> >>     /* Now that we've calculated the offset to the start of the
> >> @@ -463,7 +483,7 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
> >>  
> >>     deref = new(mem_ctx) ir_dereference_variable(load_var);
> >>     emit_access(false, deref, load_offset, const_offset,
> >> -               row_major, matrix_columns, 0);
> >> +               row_major, matrix_columns, false, 0);
> >>     *rvalue = deref;
> >>  
> >>     progress = true;
> >> @@ -581,6 +601,7 @@ lower_ubo_reference_visitor::emit_access(bool is_write,
> >>                                           unsigned int deref_offset,
> >>                                           bool row_major,
> >>                                           int matrix_columns,
> >> +                                         bool is_std430,
> >>                                           unsigned write_mask)
> >>  {
> >>     if (deref->type->is_record()) {
> >> @@ -599,7 +620,7 @@ lower_ubo_reference_visitor::emit_access(bool is_write,
> >>  
> >>           emit_access(is_write, field_deref, base_offset,
> >>                       deref_offset + field_offset,
> >> -                     row_major, 1,
> >> +                     row_major, 1, is_std430,
> >>                       writemask_for_size(field_deref->type->vector_elements));
> >>  
> >>           field_offset += field->type->std140_size(row_major);
> >> @@ -608,7 +629,8 @@ lower_ubo_reference_visitor::emit_access(bool is_write,
> >>     }
> >>  
> >>     if (deref->type->is_array()) {
> >> -      unsigned array_stride =
> >> +      unsigned array_stride = is_std430 ?
> >> +         deref->type->fields.array->std430_array_stride(row_major) :
> >>           glsl_align(deref->type->fields.array->std140_size(row_major), 16);
> >>  
> >>        for (unsigned i = 0; i < deref->type->length; i++) {
> >> @@ -618,7 +640,7 @@ lower_ubo_reference_visitor::emit_access(bool is_write,
> >>                                                element);
> >>           emit_access(is_write, element_deref, base_offset,
> >>                       deref_offset + i * array_stride,
> >> -                     row_major, 1,
> >> +                     row_major, 1, is_std430,
> >>                       writemask_for_size(element_deref->type->vector_elements));
> >>        }
> >>        return;
> >> @@ -637,7 +659,7 @@ lower_ubo_reference_visitor::emit_access(bool is_write,
> >>              int size_mul = deref->type->is_double() ? 8 : 4;
> >>              emit_access(is_write, col_deref, base_offset,
> >>                          deref_offset + i * size_mul,
> >> -                        row_major, deref->type->matrix_columns,
> >> +                        row_major, deref->type->matrix_columns, is_std430,
> >>                          writemask_for_size(col_deref->type->vector_elements));
> >>           } else {
> >>              /* std140 always rounds the stride of arrays (and matrices) to a
> >> @@ -646,9 +668,26 @@ lower_ubo_reference_visitor::emit_access(bool is_write,
> >>               */
> >>              int size_mul = (deref->type->is_double() &&
> >>                              deref->type->vector_elements > 2) ? 32 : 16;
> >> +
> >> +            /* std430 doesn't round up to a vec4 */
> >> +            if (is_std430) {
> >> +               if (deref->type->vector_elements <= 2) {
> >> +                  size_mul = deref->type->is_double() ?
> >> +                     8 * deref->type->vector_elements :
> >> +                     4 * deref->type->vector_elements;
> >> +               } else {
> >> +                  /* If the member is a three-component vector with components
> >> +                   * consuming N basic machine units, the base alignment is 4N.
> >> +                   * For vec4, base alignment is 4N.
> >> +                   */
> >> +                  size_mul = (deref->type->is_double() &&
> >> +                              deref->type->vector_elements > 2) ? 32 : 16;
> > 
> > Notice size_mul is reassigned the same value here as above?
> > 
> 
> Yes, it is the same value. I put it explicitly together with the comment
> to show that it is intended (because vec3 and vec4 have a base alignment
> equals to 4*N also in std430).
> 
> > Would this work?
> > 
> >             int size_mul;
> > 
> >             if (is_std430 && deref->type->vector_elements == 2 &&
> >                 !deref->type->is_double()) {
> >                size_mul = 8;
> >             } else {
> >                size_mul = (deref->type->is_double() &&
> >                            deref->type->vector_elements > 2) ? 32 : 16;
> >             }
> > 
> 
> Yes, it would work. I will do it.
> 
> > I'm assuming vector_elements can't be 1. I'm not certain on that, but,
> > https://www.opengl.org/wiki/Data_Type_(GLSL)#Matrices seems to agree
> > with this.
> > 
> 
> Yeah, we can assume vector_elements can't be 1 as we are processing
> matrices here.

I think the comments in this section are still not the greatest, but I
just can't make any good suggestions, so I'll just add:

Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>

> >> +               }
> >> +            }
> >> +
> >>              emit_access(is_write, col_deref, base_offset,
> >>                          deref_offset + i * size_mul,
> >> -                        row_major, deref->type->matrix_columns,
> >> +                        row_major, deref->type->matrix_columns, is_std430,
> >>                          writemask_for_size(col_deref->type->vector_elements));
> >>           }
> >>        }
> >> @@ -727,13 +766,16 @@ lower_ubo_reference_visitor::write_to_memory(ir_dereference *deref,
> >>     unsigned const_offset;
> >>     bool row_major;
> >>     int matrix_columns;
> >> +   unsigned packing = var->get_interface_type()->interface_packing;
> >> +   bool is_std430 = packing == GLSL_INTERFACE_PACKING_STD430;
> >>  
> >>     /* Compute the offset to the start if the dereference as well as other
> >>      * information we need to configure the write
> >>      */
> >>     setup_for_load_or_store(var, deref,
> >>                             &offset, &const_offset,
> >> -                           &row_major, &matrix_columns);
> >> +                           &row_major, &matrix_columns,
> >> +                           packing);
> >>     assert(offset);
> >>  
> >>     /* Now emit writes from the temporary to memory */
> >> @@ -747,7 +789,7 @@ lower_ubo_reference_visitor::write_to_memory(ir_dereference *deref,
> >>  
> >>     deref = new(mem_ctx) ir_dereference_variable(write_var);
> >>     emit_access(true, deref, write_offset, const_offset,
> >> -               row_major, matrix_columns, write_mask);
> >> +               row_major, matrix_columns, is_std430, write_mask);
> >>  }
> >>  
> >>  ir_visitor_status
> >> @@ -830,7 +872,8 @@ lower_ubo_reference_visitor::emit_ssbo_get_buffer_size()
> >>  }
> >>  
> >>  unsigned
> >> -lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *deref)
> >> +lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *deref,
> >> +                                                            unsigned packing)
> >>  {
> >>     unsigned array_stride = 0;
> >>  
> >> @@ -852,8 +895,12 @@ lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *dere
> >>        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);
> >> +      if (packing == GLSL_INTERFACE_PACKING_STD430) {
> >> +         array_stride = unsized_array_type->std430_array_stride(array_row_major);
> >> +      } else {
> >> +         array_stride = unsized_array_type->std140_size(array_row_major);
> >> +         array_stride = glsl_align(array_stride, 16);
> >> +      }
> >>        break;
> >>     }
> >>     case ir_type_dereference_record:
> >> @@ -868,8 +915,13 @@ lower_ubo_reference_visitor::calculate_unsized_array_stride(ir_dereference *dere
> >>  
> >>        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);
> >> +
> >> +      if (packing == GLSL_INTERFACE_PACKING_STD430) {
> >> +         array_stride = unsized_array_type->std430_array_stride(array_row_major);
> >> +      } else {
> >> +         array_stride = unsized_array_type->std140_size(array_row_major);
> >> +         array_stride = glsl_align(array_stride, 16);
> >> +      }
> >>        break;
> >>     }
> >>     default:
> >> @@ -889,14 +941,16 @@ lower_ubo_reference_visitor::process_ssbo_unsized_array_length(ir_rvalue **rvalu
> >>     unsigned const_offset;
> >>     bool row_major;
> >>     int matrix_columns;
> >> -   int unsized_array_stride = calculate_unsized_array_stride(deref);
> >> +   unsigned packing = var->get_interface_type()->interface_packing;
> >> +   int unsized_array_stride = calculate_unsized_array_stride(deref, packing);
> >>  
> >>     /* Compute the offset to the start if the dereference as well as other
> >>      * information we need to calculate the length.
> >>      */
> >>     setup_for_load_or_store(var, deref,
> >>                             &base_offset, &const_offset,
> >> -                           &row_major, &matrix_columns);
> >> +                           &row_major, &matrix_columns,
> >> +                           packing);
> >>     /* array.length() =
> >>      *  max((buffer_object_size - offset_of_array) / stride_of_array, 0)
> >>      */
> >> -- 
> >> 1.9.1
> >>
> > 


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