CL-USER> (disassemble #'my-fast-fib)
; disassembly for MY-FAST-FIB
; Size: 51 bytes. Origin: #x52D32449
; 49:       BB02000000       MOV EBX, 2                       ; no-arg-parsing entry point
; 4E:       488BD3           MOV RDX, RBX
; 51:       B904000000       MOV ECX, 4
; 56:       488BC3           MOV RAX, RBX
; 59:       EB13             JMP L1
; 5B:       0F1F440000       NOP
; 60: L0:   488D0413         LEA RAX, [RBX+RDX]
; 64:       488BDA           MOV RBX, RDX
; 67:       488BD0           MOV RDX, RAX
; 6A:       4883C102         ADD RCX, 2
; 6E: L1:   4839F1           CMP RCX, RSI
; 71:       7CED             JL L0
; 73:       488BD0           MOV RDX, RAX
; 76:       488BE5           MOV RSP, RBP
; 79:       F8               CLC
; 7A:       5D               POP RBP
; 7B:       C3               RET