+static struct set *
+get_complex_used_vars(nir_shader *shader, void *mem_ctx)
+{
+ struct set *complex_vars = _mesa_pointer_set_create(mem_ctx);
+
+ nir_foreach_function(function, shader) {
+ if (!function->impl)
+ continue;
+
+ nir_foreach_block(block, function->impl) {
+ nir_foreach_instr(instr, block) {
+ if (instr->type != nir_instr_type_deref)
+ continue;
+
+ nir_deref_instr *deref = nir_instr_as_deref(instr);
+
+ /* We only need to consider var derefs because
+ * nir_deref_instr_has_complex_use is recursive.
+ */
+ if (deref->deref_type == nir_deref_type_var &&
+ nir_deref_instr_has_complex_use(deref))
+ _mesa_set_add(complex_vars, deref->var);
+ }
+ }
+ }
+
+ return complex_vars;
+}