format ms64 coff section '.text' code readable executable use64 public _loop _loop: mov rax, rcx @loop_loop: mul rcx nop nop nop loop @loop_loop ; lol ret public _tail_recursion _tail_recursion: test ecx, ecx je @is_0 mov eax, ecx dec ecx @loop: test ecx, ecx jz @tr_end mul ecx dec ecx jnz @loop jmp @tr_end @is_0: mov eax, 1 @tr_end: ret