What does this Assembly snippet output?

1.global _main
2.align 2
3_main:
4    stp x29, x30, [sp, #-32]!
5    mov w8, #0xFF
6    sbfx w8, w8, #0, #4
7    sub sp, sp, #16
8    str x8, [sp]
9    adrp x0, fmt@PAGE
10    add x0, x0, fmt@PAGEOFF
11    bl _printf
12    add sp, sp, #16
13    ldp x29, x30, [sp], #32
14    mov w0, #0
15    ret
16.section __TEXT,__cstring
17fmt: .asciz "%d\n"