for(i = 0; i < n_classes; ++i) {
const arch_register_class_t *cls = arch_env_get_reg_class(arch_env, i);
unsigned n_regs = arch_register_class_n_regs(cls);
for(i = 0; i < n_classes; ++i) {
const arch_register_class_t *cls = arch_env_get_reg_class(arch_env, i);
unsigned n_regs = arch_register_class_n_regs(cls);