if (ARCH_AARCH64)
        flags = ff_get_cpu_flags_aarch64();
    if (ARCH_ARM)
        flags = ff_get_cpu_flags_arm();
    if (ARCH_PPC)
        flags = ff_get_cpu_flags_ppc();
    if (ARCH_X86)
        flags = ff_get_cpu_flags_x86();

    checked = 1;
    return flags;
}

================An error during building:

cpu.c
--disable-optimizations
unresolved symbols ff_get_cpu_flags_aarch64 ...

================ May be this variant ll be better?

 #if (ARCH_AARCH64)
        flags = ff_get_cpu_flags_aarch64();
 #elseif (ARCH_ARM)
        flags = ff_get_cpu_flags_arm();
 #elseif (ARCH_PPC)
        flags = ff_get_cpu_flags_ppc();
 #elseif (ARCH_X86)
        flags = ff_get_cpu_flags_x86();
#endif