messing with popcnt

popcnt.c

#include <stdio.h>

int main(void) {
    int input;
    scanf("%d", &input);
    printf("%s", __builtin_popcount(input));
}

popcnt.s

        .section        __TEXT,__text,regular,pure_instructions
        .build_version macos, 14, 0     sdk_version 14, 2
        .globl  _main                           ; -- Begin function main
        .p2align        2
_main:                                  ; @main
        .cfi_startproc
; %bb.0:
        sub     sp, sp, #32
        .cfi_def_cfa_offset 32
        stp     x29, x30, [sp, #16]             ; 16-byte Folded Spill
        add     x29, sp, #16
        .cfi_def_cfa w29, 16
        .cfi_offset w30, -8
        .cfi_offset w29, -16
        mov     x9, sp
        sub     x8, x29, #4
        str     x8, [x9]
        adrp    x0, l_.str@PAGE
        add     x0, x0, l_.str@PAGEOFF
        bl      _scanf
        ldur    w8, [x29, #-4]
                                        ; kill: def $x8 killed $w8
        fmov    d0, x8
        cnt.8b  v0, v0
        uaddlv.8b       h1, v0
                                        ; implicit-def: $q0
        fmov    s0, s1
                                        ; kill: def $s0 killed $s0 killed $q0
        mov     x9, sp
        fmov    w10, s0
                                        ; implicit-def: $x8
        mov     x8, x10
        str     x8, [x9]
        adrp    x0, l_.str.1@PAGE
        add     x0, x0, l_.str.1@PAGEOFF
        bl      _printf
        mov     w0, #0
        ldp     x29, x30, [sp, #16]             ; 16-byte Folded Reload
        add     sp, sp, #32
        ret
        .cfi_endproc
                                        ; -- End function
        .section        __TEXT,__cstring,cstring_literals
l_.str:                                 ; @.str
        .asciz  "%d"

l_.str.1:                               ; @.str.1
        .asciz  "%s"

.subsections_via_symbols