}
}
+/**
+ * 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
+ */
+ 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_variable *var,
+ ir_rvalue *deref,
+ ir_rvalue **offset,
+ unsigned *const_offset,
+ bool *row_major,
+ int *matrix_columns,
+ unsigned 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_double())
+ 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_double())
+ 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);
+
+ intra_struct_offset = glsl_align(intra_struct_offset, field_align);
+
+ if (strcmp(struct_type->fields.structure[i].name,
+ deref_record->field) == 0)
+ 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 */
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