4.7.8 Calling Functions

Functions are called using an rcall instruction. If your target device has more than 8kB of program memory, it will use a larger call instruction to be able to reach any function, regardless of where it is located in program memory.

If you can guarantee that all call destinations are within range of the rcall instruction, the shorter form of call can be requested by using the -mshort-calls option (see Short-calls Option).