Set and clear GPIO pins at the same time

Hey,

currently I use nrf_gpio_pins_set() and and nrf_gpio_pins_clear() from nrf_gpio.h to set and clear specific GPIO ports, respectively. If I want to change the current state of -say- 4 GPIO ports at once (some of them may be cleared, some of them may be set), how do I do that? It would be important that the change on all pins happens at the same time.

Any ideas? Thanks, NewtoM