-/* Returns a load_const instruction that represents the constant
- * initializer for the given deref chain. The caller is responsible for
- * ensuring that there actually is a constant initializer.
- */
-static nir_load_const_instr *
-get_const_initializer_load(const nir_deref_var *deref,
- struct lower_variables_state *state)
-{
- nir_constant *constant = deref->var->constant_initializer;
- const nir_deref *tail = &deref->deref;
- unsigned matrix_offset = 0;
- while (tail->child) {
- switch (tail->child->deref_type) {
- case nir_deref_type_array: {
- nir_deref_array *arr = nir_deref_as_array(tail->child);
- assert(arr->deref_array_type == nir_deref_array_type_direct);
- if (glsl_type_is_matrix(tail->type)) {
- assert(arr->deref.child == NULL);
- matrix_offset = arr->base_offset;
- } else {
- constant = constant->elements[arr->base_offset];
- }
- break;
- }
-
- case nir_deref_type_struct: {
- constant = constant->elements[nir_deref_as_struct(tail->child)->index];
- break;
- }
-
- default:
- unreachable("Invalid deref child type");
- }
-
- tail = tail->child;
- }
-
- nir_load_const_instr *load =
- nir_load_const_instr_create(state->mem_ctx,
- glsl_get_vector_elements(tail->type));
-
- matrix_offset *= load->def.num_components;
- for (unsigned i = 0; i < load->def.num_components; i++) {
- switch (glsl_get_base_type(tail->type)) {
- case GLSL_TYPE_FLOAT:
- case GLSL_TYPE_INT:
- case GLSL_TYPE_UINT:
- load->value.u[i] = constant->value.u[matrix_offset + i];
- break;
- case GLSL_TYPE_BOOL:
- load->value.u[i] = constant->value.b[matrix_offset + i] ?
- NIR_TRUE : NIR_FALSE;
- break;
- default:
- unreachable("Invalid immediate type");
- }
- }
-
- return load;
-}
-