stosd
Store doubleword to string
Stores eax at [rdi], then advances rdi by 4, backward when DF is set.
386 and later
CFPFAFZFSFDFOF –––––––
- Changes no flag
- Reads DF
Forms
stosd
The d suffix selects an element of 4 bytes. After each element, the instruction increases rdi by 4 when DF = 0, or decreases rdi by 4 when DF = 1. In 64-bit mode the default addresses use rdi. The a32 address-size prefix instead uses edi; 16-bit string addressing is unavailable.
rep repeats until the counter reaches zero. The counter is rcx by default or ecx with a32. If it starts at zero, a repeated instruction accesses no element. The data width is independent of this address and counter width.
global _start
section .text
_start:
mov rax, 12
mov rbx, 5
mov rcx, 3
mov rsi, 9
stosd
mov rax, 60 ; syscall 60: exit
xor rdi, rdi
syscall