cbw
Sign-extend al into ax
Sign-extends al into ax, filling ah with copies of the sign bit of al.
8086 and later
CFPFAFZFSFDFOF –––––––
- Changes no flag
Forms
cbw
The rest of rax is unchanged.
global _start
section .text
_start:
mov rax, 12
mov rbx, 5
mov rcx, 3
mov rsi, 9
cbw
mov rax, 60 ; syscall 60: exit
xor rdi, rdi
syscall