AS_HELP_STRING([--enable-neon-opt], [Enable NEON optimisations on ARM CPUs that support it]))
AS_IF([test "x$enable_neon_opt" != "xno"],
AS_HELP_STRING([--enable-neon-opt], [Enable NEON optimisations on ARM CPUs that support it]))
AS_IF([test "x$enable_neon_opt" != "xno"],