| /* |
| * Copyright (c) 2015 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_buffer_access.cpp |
| * |
| * Helper for IR lowering pass to replace dereferences of buffer object based |
| * shader variables with intrinsic function calls. |
| * |
| * This helper is used by lowering passes for UBOs, SSBOs and compute shader |
| * shared variables. |
| */ |
| |
| #include "lower_buffer_access.h" |
| #include "ir_builder.h" |
| #include "main/macros.h" |
| #include "util/list.h" |
| #include "glsl_parser_extras.h" |
| |
| using namespace ir_builder; |
| |
| namespace lower_buffer_access { |
| |
| static inline int |
| writemask_for_size(unsigned n) |
| { |
| return ((1 << n) - 1); |
| } |
| |
| /** |
| * Takes a deref and recursively calls itself to break the deref down to the |
| * point that the reads or writes generated are contiguous scalars or vectors. |
| */ |
| void |
| lower_buffer_access::emit_access(void *mem_ctx, |
| bool is_write, |
| ir_dereference *deref, |
| ir_variable *base_offset, |
| unsigned int deref_offset, |
| bool row_major, |
| int matrix_columns, |
| unsigned int packing, |
| unsigned int write_mask) |
| { |
| 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_access(mem_ctx, is_write, field_deref, base_offset, |
| deref_offset + field_offset, |
| row_major, 1, packing, |
| writemask_for_size(field_deref->type->vector_elements)); |
| |
| field_offset += field->type->std140_size(row_major); |
| } |
| return; |
| } |
| |
| if (deref->type->is_array()) { |
| unsigned array_stride = packing == GLSL_INTERFACE_PACKING_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++) { |
| 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_access(mem_ctx, is_write, element_deref, base_offset, |
| deref_offset + i * array_stride, |
| row_major, 1, packing, |
| writemask_for_size(element_deref->type->vector_elements)); |
| } |
| 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_64bit() ? 8 : 4; |
| emit_access(mem_ctx, is_write, col_deref, base_offset, |
| deref_offset + i * size_mul, |
| row_major, deref->type->matrix_columns, packing, |
| writemask_for_size(col_deref->type->vector_elements)); |
| } else { |
| int size_mul; |
| |
| /* std430 doesn't round up vec2 size to a vec4 size */ |
| if (packing == GLSL_INTERFACE_PACKING_STD430 && |
| deref->type->vector_elements == 2 && |
| !deref->type->is_64bit()) { |
| size_mul = 8; |
| } 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. |
| * |
| * For both std140 and std430, 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_64bit() && |
| deref->type->vector_elements > 2) ? 32 : 16; |
| } |
| |
| emit_access(mem_ctx, is_write, col_deref, base_offset, |
| deref_offset + i * size_mul, |
| row_major, deref->type->matrix_columns, packing, |
| writemask_for_size(col_deref->type->vector_elements)); |
| } |
| } |
| 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)); |
| unsigned mask = |
| is_write ? write_mask : (1 << deref->type->vector_elements) - 1; |
| insert_buffer_access(mem_ctx, deref, deref->type, offset, mask, -1); |
| } else { |
| unsigned N = deref->type->is_64bit() ? 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 = 0; |
| /* Matrix stride for std430 mat2xY matrices are not rounded up to |
| * vec4 size. From OpenGL 4.3 spec, section 7.6.2.2 "Standard Uniform |
| * Block Layout": |
| * |
| * "2. If the member is a two- or four-component vector with components |
| * consuming N basic machine units, the base alignment is 2N or 4N, |
| * respectively." [...] |
| * "4. If the member is an array of scalars or vectors, the base alignment |
| * and array stride are set to match the base alignment of a single array |
| * element, according to rules (1), (2), and (3), and rounded up to the |
| * base alignment of a vec4." [...] |
| * "7. If the member is a row-major matrix with C columns and R rows, the |
| * matrix is stored identically to an array of R row vectors with C |
| * components each, according to rule (4)." [...] |
| * "When using the std430 storage layout, shader storage blocks will be |
| * laid out in buffer storage identically to uniform and shader storage |
| * blocks using the std140 layout, except that the base alignment and |
| * stride of arrays of scalars and vectors in rule 4 and of structures in |
| * rule 9 are not rounded up a multiple of the base alignment of a vec4." |
| */ |
| if (packing == GLSL_INTERFACE_PACKING_STD430 && matrix_columns == 2) |
| matrix_stride = 2 * N; |
| else |
| matrix_stride = glsl_align(matrix_columns * N, 16); |
| |
| const glsl_type *deref_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)); |
| if (!is_write || ((1U << i) & write_mask)) |
| insert_buffer_access(mem_ctx, deref, deref_type, chan_offset, |
| (1U << i), i); |
| } |
| } |
| } |
| |
| /** |
| * 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. |
| */ |
| bool |
| lower_buffer_access::is_dereferenced_thing_row_major(const ir_rvalue *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: { |
| /* For interface block matrix variables we handle inherited |
| * layouts at HIR generation time, but we don't do that for shared |
| * variables, which are always column-major |
| */ |
| MAYBE_UNUSED ir_variable *var = deref->variable_referenced(); |
| assert((var->is_in_buffer_block() && !matrix) || |
| var->data.mode == ir_var_shader_shared); |
| 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; |
| } |
| |
| /** |
| * This function initializes various values that will be used later by |
| * emit_access when actually emitting loads or stores. |
| * |
| * Note: const_offset is an input as well as an output, clients must |
| * initialize it to the offset of the variable in the underlying block, and |
| * this function will adjust it by adding the constant offset of the member |
| * being accessed into that variable. |
| */ |
| void |
| lower_buffer_access::setup_buffer_access(void *mem_ctx, |
| ir_rvalue *deref, |
| ir_rvalue **offset, |
| unsigned *const_offset, |
| bool *row_major, |
| int *matrix_columns, |
| const glsl_struct_field **struct_field, |
| enum glsl_interface_packing packing) |
| { |
| *offset = new(mem_ctx) ir_constant(0u); |
| *row_major = is_dereferenced_thing_row_major(deref); |
| *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: { |
| 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_vector()) { |
| /* We get this when storing or loading a component out of a vector |
| * with a non-constant index. This happens for v[i] = f where v is |
| * a vector (or m[i][j] = f where m is a matrix). If we don't |
| * lower that here, it gets turned into v = vector_insert(v, i, |
| * f), which loads the entire vector, modifies one component and |
| * then write the entire thing back. That breaks if another |
| * thread or SIMD channel is modifying the same vector. |
| */ |
| array_stride = 4; |
| if (deref_array->array->type->is_64bit()) |
| array_stride *= 2; |
| } else 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_64bit()) |
| array_stride *= 2; |
| *matrix_columns = deref_array->array->type->matrix_columns; |
| } else if (deref_array->type->without_array()->is_interface()) { |
| /* We're processing an array dereference of an interface instance |
| * array. The thing being dereferenced *must* be a variable |
| * dereference because interfaces cannot be embedded in 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. |
| */ |
| 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); |
| |
| /* 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; |
| 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 = 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); |
| |
| if (struct_type->fields.structure[i].offset != -1) { |
| intra_struct_offset = struct_type->fields.structure[i].offset; |
| } |
| |
| intra_struct_offset = glsl_align(intra_struct_offset, field_align); |
| |
| if (strcmp(struct_type->fields.structure[i].name, |
| deref_record->field) == 0) { |
| if (struct_field) |
| *struct_field = &struct_type->fields.structure[i]; |
| break; |
| } |
| |
| 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: |
| * |
| * "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; |
| } |
| |
| case ir_type_swizzle: { |
| ir_swizzle *deref_swizzle = (ir_swizzle *) deref; |
| |
| assert(deref_swizzle->mask.num_components == 1); |
| |
| *const_offset += deref_swizzle->mask.x * sizeof(int); |
| deref = deref_swizzle->val->as_dereference(); |
| break; |
| } |
| |
| default: |
| assert(!"not reached"); |
| deref = NULL; |
| break; |
| } |
| } |
| } |
| |
| } /* namespace lower_buffer_access */ |
