https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107370
--- Comment #9 from jacob navia <jacob at jacob dot remcomp.fr> --- Actually, this looks that a bug in all versions of gcc! Using the "GP" calculator I obtain: 1.414213562373095048801688724209698078 Using the "bc" calculator ~ % bc bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. scale=33 sqrt(2) 1.414213562373095048801688724209698 All agree: gcc is just wrong.