option casemap:none
option literals:on

printf    proto :dword, :VARARG
exit      proto :dword

.data
  s   db "Goodbye, World!",0

.data?
  d   db 20 dup (?)
  dp  dq ?
  tb  dd ?

.code
main proc
  lea rsi, s                    ;; Put the address of var S into the source index(RSI)
  xor rcx, rcx                  ;; Zero out RCX
  _getsize:
    inc rcx                     ;; Advanced the index by 1
    cmp byte ptr [rsi+rcx],0    ;; check the current byte for terminating 0
    jne _getsize                ;; nope, jump back and check again

  mov tb, ecx                   ;; tb = Total bytes, Keep a copy of the size of the string
  lea rsi, s                    ;; Copy the address of s into the source index(rsi)
  lea rdi, d                    ;; Copy the address of d into the destination index(rdi)
  rep movsb                     ;; Copy bytes from ESI to EDI until RCX is 0

  lea rax, s                    ;; Get the address of S
  mov dp, rax                   ;; Copy it from RAX to dp

  mov rbx,rdi                   ;; Make a copy of RDI, cause over writes due to ABI call args T_T
  invoke printf, CSTR("-> s (0x%x) = %s",10), rsi, addr s
  invoke printf, CSTR("-> d (0x%x) = %s",10), rbx, addr d
  invoke printf, CSTR("-> dp (0x%x) = %s",10), addr dp, dp
  invoke printf, CSTR("-> bytes copied: %i",10), tb
  xor rsi, rsi
  call exit
  ret
main endp

end