Code in this sub-directory should follow the GNU Coding Standard, but it is
not expected to be upstreamed into glibc without modification, so
glibc-specific conventions need not be followed.

The requirements for portable code apply to non-portable code with the
following differences:

1. Worst-case ULP error should be encoded in filenames (e.g. sin_u35.c). There
   are no specific restrictions on acceptable ULP error, but if functions
   provide significantly less accuracy than portable equivalents then a clear
   justification for inclusion should be stated in comments at the top of the
   source file. Error bounds of the approximation should be clearly documented
   in comments.

2. Functions are assumed to support round-to-nearest mode by default, unless
   stated; other rounding modes are not required to be provided.