| /* |
| * Copyright © 2012 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| /** |
| * \file lower_ubo_reference.cpp |
| * |
| * IR lower pass to replace dereferences of variables in a uniform |
| * buffer object with usage of ir_binop_ubo_load expressions, each of |
| * which can read data up to the size of a vec4. |
| * |
| * This relieves drivers of the responsibility to deal with tricky UBO |
| * layout issues like std140 structures and row_major matrices on |
| * their own. |
| */ |
| |
| #include "ir.h" |
| #include "ir_builder.h" |
| #include "ir_rvalue_visitor.h" |
| #include "main/macros.h" |
| |
| using namespace ir_builder; |
| |
| namespace { |
| class lower_ubo_reference_visitor : public ir_rvalue_enter_visitor { |
| public: |
| lower_ubo_reference_visitor(struct gl_shader *shader) |
| : shader(shader) |
| { |
| } |
| |
| void handle_rvalue(ir_rvalue **rvalue); |
| void emit_ubo_loads(ir_dereference *deref, ir_variable *base_offset, |
| unsigned int deref_offset); |
| ir_expression *ubo_load(const struct glsl_type *type, |
| ir_rvalue *offset); |
| |
| void *mem_ctx; |
| struct gl_shader *shader; |
| struct gl_uniform_buffer_variable *ubo_var; |
| unsigned uniform_block; |
| bool progress; |
| }; |
| |
| /** |
| * Determine the name of the interface block field |
| * |
| * This is the name of the specific member as it would appear in the |
| * \c gl_uniform_buffer_variable::Name field in the shader's |
| * \c UniformBlocks array. |
| */ |
| static const char * |
| interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d) |
| { |
| ir_constant *previous_index = NULL; |
| |
| while (d != NULL) { |
| switch (d->ir_type) { |
| case ir_type_dereference_variable: { |
| ir_dereference_variable *v = (ir_dereference_variable *) d; |
| if (previous_index |
| && v->var->is_interface_instance() |
| && v->var->type->is_array()) |
| return ralloc_asprintf(mem_ctx, |
| "%s[%d]", |
| base_name, |
| previous_index->get_uint_component(0)); |
| else |
| return base_name; |
| |
| break; |
| } |
| |
| case ir_type_dereference_record: { |
| ir_dereference_record *r = (ir_dereference_record *) d; |
| |
| d = r->record->as_dereference(); |
| break; |
| } |
| |
| case ir_type_dereference_array: { |
| ir_dereference_array *a = (ir_dereference_array *) d; |
| |
| d = a->array->as_dereference(); |
| previous_index = a->array_index->as_constant(); |
| break; |
| } |
| |
| default: |
| assert(!"Should not get here."); |
| break; |
| } |
| } |
| |
| assert(!"Should not get here."); |
| return NULL; |
| } |
| |
| void |
| lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue) |
| { |
| if (!*rvalue) |
| return; |
| |
| ir_dereference *deref = (*rvalue)->as_dereference(); |
| if (!deref) |
| return; |
| |
| ir_variable *var = deref->variable_referenced(); |
| if (!var || !var->is_in_uniform_block()) |
| return; |
| |
| mem_ctx = ralloc_parent(*rvalue); |
| |
| const char *const field_name = |
| interface_field_name(mem_ctx, (char *) var->interface_type->name, deref); |
| |
| this->uniform_block = -1; |
| for (unsigned i = 0; i < shader->NumUniformBlocks; i++) { |
| if (strcmp(field_name, shader->UniformBlocks[i].Name) == 0) { |
| this->uniform_block = i; |
| |
| struct gl_uniform_block *block = &shader->UniformBlocks[i]; |
| |
| this->ubo_var = var->is_interface_instance() |
| ? &block->Uniforms[0] : &block->Uniforms[var->location]; |
| |
| break; |
| } |
| } |
| |
| assert(this->uniform_block != (unsigned) -1); |
| |
| ir_rvalue *offset = new(mem_ctx) ir_constant(0u); |
| unsigned const_offset = 0; |
| bool row_major = ubo_var->RowMajor; |
| |
| /* Calculate the offset to the start of the region of the UBO |
| * dereferenced by *rvalue. This may be a variable offset if an |
| * array dereference has a variable index. |
| */ |
| while (deref) { |
| switch (deref->ir_type) { |
| case ir_type_dereference_variable: { |
| const_offset += ubo_var->Offset; |
| deref = NULL; |
| break; |
| } |
| |
| case ir_type_dereference_array: { |
| ir_dereference_array *deref_array = (ir_dereference_array *)deref; |
| unsigned array_stride; |
| if (deref_array->array->type->is_matrix() && row_major) { |
| /* When loading a vector out of a row major matrix, the |
| * step between the columns (vectors) is the size of a |
| * float, while the step between the rows (elements of a |
| * vector) is handled below in emit_ubo_loads. |
| */ |
| array_stride = 4; |
| } else if (deref_array->type->is_interface()) { |
| /* We're processing an array dereference of an interface instance |
| * array. The thing being dereferenced *must* be a variable |
| * dereference because intefaces cannot be embedded an other |
| * types. In terms of calculating the offsets for the lowering |
| * pass, we don't care about the array index. All elements of an |
| * interface instance array will have the same offsets relative to |
| * the base of the block that backs them. |
| */ |
| assert(deref_array->array->as_dereference_variable()); |
| deref = deref_array->array->as_dereference(); |
| break; |
| } else { |
| array_stride = deref_array->type->std140_size(row_major); |
| array_stride = glsl_align(array_stride, 16); |
| } |
| |
| ir_constant *const_index = deref_array->array_index->as_constant(); |
| if (const_index) { |
| const_offset += array_stride * const_index->value.i[0]; |
| } else { |
| offset = add(offset, |
| mul(deref_array->array_index, |
| new(mem_ctx) ir_constant(array_stride))); |
| } |
| deref = deref_array->array->as_dereference(); |
| break; |
| } |
| |
| case ir_type_dereference_record: { |
| ir_dereference_record *deref_record = (ir_dereference_record *)deref; |
| const glsl_type *struct_type = deref_record->record->type; |
| unsigned intra_struct_offset = 0; |
| |
| unsigned max_field_align = 16; |
| for (unsigned int i = 0; i < struct_type->length; i++) { |
| const glsl_type *type = struct_type->fields.structure[i].type; |
| unsigned field_align = type->std140_base_alignment(row_major); |
| max_field_align = MAX2(field_align, max_field_align); |
| intra_struct_offset = glsl_align(intra_struct_offset, field_align); |
| |
| if (strcmp(struct_type->fields.structure[i].name, |
| deref_record->field) == 0) |
| break; |
| intra_struct_offset += type->std140_size(row_major); |
| } |
| |
| const_offset = glsl_align(const_offset, max_field_align); |
| const_offset += intra_struct_offset; |
| |
| deref = deref_record->record->as_dereference(); |
| break; |
| } |
| default: |
| assert(!"not reached"); |
| deref = NULL; |
| break; |
| } |
| } |
| |
| /* Now that we've calculated the offset to the start of the |
| * dereference, walk over the type and emit loads into a temporary. |
| */ |
| const glsl_type *type = (*rvalue)->type; |
| ir_variable *load_var = new(mem_ctx) ir_variable(type, |
| "ubo_load_temp", |
| ir_var_temporary); |
| base_ir->insert_before(load_var); |
| |
| ir_variable *load_offset = new(mem_ctx) ir_variable(glsl_type::uint_type, |
| "ubo_load_temp_offset", |
| ir_var_temporary); |
| base_ir->insert_before(load_offset); |
| base_ir->insert_before(assign(load_offset, offset)); |
| |
| deref = new(mem_ctx) ir_dereference_variable(load_var); |
| emit_ubo_loads(deref, load_offset, const_offset); |
| *rvalue = deref; |
| |
| progress = true; |
| } |
| |
| ir_expression * |
| lower_ubo_reference_visitor::ubo_load(const glsl_type *type, |
| ir_rvalue *offset) |
| { |
| return new(mem_ctx) |
| ir_expression(ir_binop_ubo_load, |
| type, |
| new(mem_ctx) ir_constant(this->uniform_block), |
| offset); |
| |
| } |
| |
| /** |
| * Takes LHS and emits a series of assignments into its components |
| * from the UBO variable at variable_offset + deref_offset. |
| * |
| * Recursively calls itself to break the deref down to the point that |
| * the ir_binop_ubo_load expressions generated are contiguous scalars |
| * or vectors. |
| */ |
| void |
| lower_ubo_reference_visitor::emit_ubo_loads(ir_dereference *deref, |
| ir_variable *base_offset, |
| unsigned int deref_offset) |
| { |
| if (deref->type->is_record()) { |
| unsigned int field_offset = 0; |
| |
| for (unsigned i = 0; i < deref->type->length; i++) { |
| const struct glsl_struct_field *field = |
| &deref->type->fields.structure[i]; |
| ir_dereference *field_deref = |
| new(mem_ctx) ir_dereference_record(deref->clone(mem_ctx, NULL), |
| field->name); |
| |
| field_offset = |
| glsl_align(field_offset, |
| field->type->std140_base_alignment(ubo_var->RowMajor)); |
| |
| emit_ubo_loads(field_deref, base_offset, deref_offset + field_offset); |
| |
| field_offset += field->type->std140_size(ubo_var->RowMajor); |
| } |
| return; |
| } |
| |
| if (deref->type->is_array()) { |
| unsigned array_stride = |
| glsl_align(deref->type->fields.array->std140_size(ubo_var->RowMajor), |
| 16); |
| |
| for (unsigned i = 0; i < deref->type->length; i++) { |
| ir_constant *element = new(mem_ctx) ir_constant(i); |
| ir_dereference *element_deref = |
| new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL), |
| element); |
| emit_ubo_loads(element_deref, base_offset, |
| deref_offset + i * array_stride); |
| } |
| return; |
| } |
| |
| if (deref->type->is_matrix()) { |
| for (unsigned i = 0; i < deref->type->matrix_columns; i++) { |
| ir_constant *col = new(mem_ctx) ir_constant(i); |
| ir_dereference *col_deref = |
| new(mem_ctx) ir_dereference_array(deref->clone(mem_ctx, NULL), |
| col); |
| |
| /* std140 always rounds the stride of arrays (and matrices) |
| * to a vec4, so matrices are always 16 between columns/rows. |
| */ |
| emit_ubo_loads(col_deref, base_offset, deref_offset + i * 16); |
| } |
| return; |
| } |
| |
| assert(deref->type->is_scalar() || |
| deref->type->is_vector()); |
| |
| if (!ubo_var->RowMajor) { |
| ir_rvalue *offset = add(base_offset, |
| new(mem_ctx) ir_constant(deref_offset)); |
| base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), |
| ubo_load(deref->type, offset))); |
| } else { |
| /* We're dereffing a column out of a row-major matrix, so we |
| * gather the vector from each stored row. |
| */ |
| assert(deref->type->base_type == GLSL_TYPE_FLOAT); |
| /* Matrices, row_major or not, are stored as if they were |
| * arrays of vectors of the appropriate size in std140. |
| * Arrays have their strides rounded up to a vec4, so the |
| * matrix stride is always 16. |
| */ |
| unsigned matrix_stride = 16; |
| |
| for (unsigned i = 0; i < deref->type->vector_elements; i++) { |
| ir_rvalue *chan_offset = |
| add(base_offset, |
| new(mem_ctx) ir_constant(deref_offset + i * matrix_stride)); |
| |
| base_ir->insert_before(assign(deref->clone(mem_ctx, NULL), |
| ubo_load(glsl_type::float_type, |
| chan_offset), |
| (1U << i))); |
| } |
| } |
| } |
| |
| } /* unnamed namespace */ |
| |
| void |
| lower_ubo_reference(struct gl_shader *shader, exec_list *instructions) |
| { |
| lower_ubo_reference_visitor v(shader); |
| |
| /* Loop over the instructions lowering references, because we take |
| * a deref of a UBO array using a UBO dereference as the index will |
| * produce a collection of instructions all of which have cloned |
| * UBO dereferences for that array index. |
| */ |
| do { |
| v.progress = false; |
| visit_list_elements(&v, instructions); |
| } while (v.progress); |
| } |