https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69227
--- Comment #2 from Andre Vieira <andre.simoesdiasvieira at arm dot com> --- I have decided to email the newlib mailinglist to figure out which function classes we should and should not support for 'arm-none-eabi'. See https://sourceware.org/ml/newlib/2016/msg00009.html