cwde
Sign-extend ax into eax
Sign-extends ax into eax, filling the upper 16 bits with copies of the sign bit of ax.
386 and later
CFPFAFZFSFDFOF –––––––
- Changes no flag
Forms
cwde
As a 32-bit register write it also clears the upper half of rax, so the result is not a signed 64-bit value: cdqe extends eax into all of rax.
global _start
section .text
_start:
mov rax, 12
mov rbx, 5
mov rcx, 3
mov rsi, 9
cwde
mov rax, 60 ; syscall 60: exit
xor rdi, rdi
syscall