However, when writing in assembly one must pay attention that at least RBX, RBP and R12 through R15 must be preserved by any function
Only if you're calling external code that assumes that. The power of Asm largely comes from not needing to follow arbitrary conventions in your own code. The boundaries where you interface to external code are the only constraints.
Only if you're calling external code that assumes that. The power of Asm largely comes from not needing to follow arbitrary conventions in your own code. The boundaries where you interface to external code are the only constraints.