@node float.h
@section @file{float.h}

POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/basedefs/float.h.html}

Gnulib module: float

Portability problems fixed by Gnulib:
@itemize
@item
The conversion from @code{int} to @code{long double} in incorrect on some
platforms:
glibc 2.7 on Linux/SPARC64.
@item
The values of @code{LDBL_*} macros are incorrect on some platforms:
On OpenBSD 4.0 and MirBSD 10, they are the same as the values of the
@code{DBL_*} macros, although @samp{long double} is a larger type than
@samp{double}.
On FreeBSD/x86 6.4, they represent the incorrect 53-bit precision assumptions
in the compiler, not the real 64-bit precision at runtime.
On Linux/PowerPC with GCC 4.4, on AIX 7.1 with GCC 4.2, and on IRIX 6.5,
they don't reflect the ``double double'' representation of @code{long double}
correctly.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
The macro @code{FLT_ROUNDS} is a constant expression and does not represent
the current rounding mode on some platforms:
glibc 2.11, HP-UX 11, mingw.
@end itemize
