gpio speed

With this:

var loop = E.asm("void()",`
    ldr    r2, port_A  //Load port_A in r2
    movw   r3, #57344  //Load mask in r3
loop:
    str    r3, [r2, #0]  //Set is r2
    str    r3, [r2, #4]  //Clear is r2+4
    b loop
    nop
    nop
port_A:
  .word    0x40010810
`);

LED1.write(0);
LED2.write(0);
LED3.write(0);

loop()

It takes 223 ns to loop once, but three cpu cycles @72MHz are 3*1e9*1/72e6= 41.6 ns, can I touch some clock setting somewhere to make it toggle faster?

Thanks,

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