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| /* |
| * 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; |
| |
| /** |
| * Determine if a thing being dereferenced is row-major |
| * |
| * There is some trickery here. |
| * |
| * If the thing being dereferenced is a member of uniform block \b without an |
| * instance name, then the name of the \c ir_variable is the field name of an |
| * interface type. If this field is row-major, then the thing referenced is |
| * row-major. |
| * |
| * If the thing being dereferenced is a member of uniform block \b with an |
| * instance name, then the last dereference in the tree will be an |
| * \c ir_dereference_record. If that record field is row-major, then the |
| * thing referenced is row-major. |
| */ |
| static bool |
| is_dereferenced_thing_row_major(const ir_dereference *deref) |
| { |
| bool matrix = false; |
| const ir_rvalue *ir = deref; |
| |
| while (true) { |
| matrix = matrix || ir->type->without_array()->is_matrix(); |
| |
| switch (ir->ir_type) { |
| case ir_type_dereference_array: { |
| const ir_dereference_array *const array_deref = |
| (const ir_dereference_array *) ir; |
| |
| ir = array_deref->array; |
| break; |
| } |
| |
| case ir_type_dereference_record: { |
| const ir_dereference_record *const record_deref = |
| (const ir_dereference_record *) ir; |
| |
| ir = record_deref->record; |
| |
| const int idx = ir->type->field_index(record_deref->field); |
| assert(idx >= 0); |
| |
| const enum glsl_matrix_layout matrix_layout = |
| glsl_matrix_layout(ir->type->fields.structure[idx].matrix_layout); |
| |
| switch (matrix_layout) { |
| case GLSL_MATRIX_LAYOUT_INHERITED: |
| break; |
| case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR: |
| return false; |
| case GLSL_MATRIX_LAYOUT_ROW_MAJOR: |
| return matrix || deref->type->without_array()->is_record(); |
| } |
| |
| break; |
| } |
| |
| case ir_type_dereference_variable: { |
| const ir_dereference_variable *const var_deref = |
| (const ir_dereference_variable *) ir; |
| |
| const enum glsl_matrix_layout matrix_layout = |
| glsl_matrix_layout(var_deref->var->data.matrix_layout); |
| |
| switch (matrix_layout) { |
| case GLSL_MATRIX_LAYOUT_INHERITED: |
| assert(!matrix); |
| return false; |
| case GLSL_MATRIX_LAYOUT_COLUMN_MAJOR: |
| return false; |
| case GLSL_MATRIX_LAYOUT_ROW_MAJOR: |
| return matrix || deref->type->without_array()->is_record(); |
| } |
| |
| unreachable("invalid matrix layout"); |
| break; |
| } |
| |
| default: |
| return false; |
| } |
| } |
| |
| /* The tree must have ended with a dereference that wasn't an |
| * ir_dereference_variable. That is invalid, and it should be impossible. |
| */ |
| unreachable("invalid dereference tree"); |
| return false; |
| } |
| |
| 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, bool row_major, |
| int matrix_columns); |
| 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; |
| ir_rvalue *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_rvalue **nonconst_block_index) |
| { |
| ir_rvalue *previous_index = NULL; |
| *nonconst_block_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()) { |
| |
| ir_constant *const_index = previous_index->as_constant(); |
| if (!const_index) { |
| *nonconst_block_index = previous_index; |
| return ralloc_asprintf(mem_ctx, "%s[0]", base_name); |
| } else { |
| return ralloc_asprintf(mem_ctx, |
| "%s[%d]", |
| base_name, |
| const_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; |
| |
| 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); |
| |
| ir_rvalue *nonconst_block_index; |
| const char *const field_name = |
| interface_field_name(mem_ctx, (char *) var->get_interface_type()->name, |
| deref, &nonconst_block_index); |
| |
| this->uniform_block = NULL; |
| for (unsigned i = 0; i < shader->NumUniformBlocks; i++) { |
| if (strcmp(field_name, shader->UniformBlocks[i].Name) == 0) { |
| |
| ir_constant *index = new(mem_ctx) ir_constant(i); |
| |
| if (nonconst_block_index) { |
| if (nonconst_block_index->type != glsl_type::uint_type) |
| nonconst_block_index = i2u(nonconst_block_index); |
| this->uniform_block = add(nonconst_block_index, index); |
| } else { |
| this->uniform_block = index; |
| } |
| |
| struct gl_uniform_block *block = &shader->UniformBlocks[i]; |
| |
| this->ubo_var = var->is_interface_instance() |
| ? &block->Uniforms[0] : &block->Uniforms[var->data.location]; |
| |
| break; |
| } |
| } |
| |
| assert(this->uniform_block); |
| |
| ir_rvalue *offset = new(mem_ctx) ir_constant(0u); |
| unsigned const_offset = 0; |
| bool row_major = is_dereferenced_thing_row_major(deref); |
| int matrix_columns = 1; |
| |
| /* 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; |
| if (deref_array->array->type->is_double()) |
| array_stride *= 2; |
| matrix_columns = deref_array->array->type->matrix_columns; |
| } 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 { |
| /* 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_array); |
| |
| 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; |
| if (array_index->type->base_type == GLSL_TYPE_INT) |
| array_index = i2u(array_index); |
| |
| ir_constant *const_index = |
| array_index->constant_expression_value(NULL); |
| if (const_index) { |
| const_offset += array_stride * const_index->value.u[0]; |
| } else { |
| offset = add(offset, |
| mul(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; |
| |
| for (unsigned int i = 0; i < struct_type->length; i++) { |
| const glsl_type *type = struct_type->fields.structure[i].type; |
| |
| ir_dereference_record *field_deref = |
| new(mem_ctx) ir_dereference_record(deref_record->record, |
| struct_type->fields.structure[i].name); |
| const bool field_row_major = |
| is_dereferenced_thing_row_major(field_deref); |
| |
| ralloc_free(field_deref); |
| |
| unsigned field_align = type->std140_base_alignment(field_row_major); |
| |
| 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(field_row_major); |
| |
| /* If the field just examined was itself a structure, apply rule |
| * #9: |
| * |
| * "The structure may have padding at the end; the base offset |
| * of the member following the sub-structure is rounded up to |
| * the next multiple of the base alignment of the structure." |
| */ |
| if (type->without_array()->is_record()) { |
| intra_struct_offset = glsl_align(intra_struct_offset, |
| 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, row_major, matrix_columns); |
| *rvalue = deref; |
| |
| progress = true; |
| } |
| |
| ir_expression * |
| lower_ubo_reference_visitor::ubo_load(const glsl_type *type, |
| ir_rvalue *offset) |
| { |
| ir_rvalue *block_ref = this->uniform_block->clone(mem_ctx, NULL); |
| return new(mem_ctx) |
| ir_expression(ir_binop_ubo_load, |
| type, |
| block_ref, |
| 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, |
| bool row_major, |
| int matrix_columns) |
| { |
| 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(row_major)); |
| |
| emit_ubo_loads(field_deref, base_offset, deref_offset + field_offset, |
| row_major, 1); |
| |
| field_offset += field->type->std140_size(row_major); |
| } |
| return; |
| } |
| |
| if (deref->type->is_array()) { |
| unsigned array_stride = |
| glsl_align(deref->type->fields.array->std140_size(row_major), |
| 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, |
| row_major, 1); |
| } |
| 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); |
| |
| if (row_major) { |
| /* For a row-major matrix, the next column starts at the next |
| * element. |
| */ |
| int size_mul = deref->type->is_double() ? 8 : 4; |
| emit_ubo_loads(col_deref, base_offset, deref_offset + i * size_mul, |
| row_major, deref->type->matrix_columns); |
| } else { |
| /* std140 always rounds the stride of arrays (and matrices) to a |
| * vec4, so matrices are always 16 between columns/rows. With |
| * doubles, they will be 32 apart when there are more than 2 rows. |
| */ |
| int size_mul = (deref->type->is_double() && |
| deref->type->vector_elements > 2) ? 32 : 16; |
| emit_ubo_loads(col_deref, base_offset, deref_offset + i * size_mul, |
| row_major, deref->type->matrix_columns); |
| } |
| } |
| return; |
| } |
| |
| assert(deref->type->is_scalar() || |
| deref->type->is_vector()); |
| |
| if (!row_major) { |
| 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 { |
| unsigned N = deref->type->is_double() ? 8 : 4; |
| |
| /* 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 || |
| deref->type->base_type == GLSL_TYPE_DOUBLE); |
| /* 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. However a double matrix may either be 16 |
| * or 32 depending on the number of columns. |
| */ |
| assert(matrix_columns <= 4); |
| unsigned matrix_stride = glsl_align(matrix_columns * N, 16); |
| |
| const glsl_type *ubo_type = deref->type->base_type == GLSL_TYPE_FLOAT ? |
| glsl_type::float_type : glsl_type::double_type; |
| |
| 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(ubo_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); |
| } |