Using ARM instruction set:

Find the shortest sequence of LEGv8 instructions that extracts bits 16 down to 11 from register X10 and uses the value of this field to replace bits 31 down to 26 in register X11 without changing the other bits of registers X10 or X11. (Be sure to test your code using X10 = 0 and X11 = 0xffffffffffffffff. Doing so may reveal a common oversight.)