lodsw
Load word from string
Loads the word at [rsi] into ax, then advances rsi by 2, backward when DF is set.
8086 and later
CFPFAFZFSFDFOF –––––––
- Changes no flag
- Reads DF
Forms
lodsw
The w suffix selects an element of 2 bytes. After each element, the instruction increases rsi by 2 when DF = 0, or decreases rsi by 2 when DF = 1. In 64-bit mode the default addresses use rsi. The a32 address-size prefix instead uses esi; 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
lodsw
mov rax, 60 ; syscall 60: exit
xor rdi, rdi
syscall