https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83206
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Version|8.0 |7.2.1 Resolution|--- |FIXED Target Milestone|--- |8.0 --- Comment #4 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- Implementation of -mfpu=auto wasn't complete in GCC-7, which is why it isn't in the main documentation. Some of the implementation was there though, which is why it leaks into the --help information. As you've noted it's fixed in gcc-8. It's unlikely that this will be fixed on the release branch.