printf, isinf, etc.: noncanonical != NaN Do not require that isinf, printf, etc. treat noncanonical values as NaNs. Instead, require only that they do not crash. Problem reported by Joseph Myers in: https://sourceware.org/ml/libc-alpha/2015-02/msg00244.html * doc/posix-functions/dprintf.texi (dprintf): * doc/posix-functions/fprintf.texi (fprintf): * doc/posix-functions/isfinite.texi (isfinite): * doc/posix-functions/isinf.texi (isinf): * doc/posix-functions/isnan.texi (isnan): * doc/posix-functions/printf.texi (printf): * doc/posix-functions/snprintf.texi (snprintf): * doc/posix-functions/sprintf.texi (sprintf): * doc/posix-functions/vdprintf.texi (vdprintf): * doc/posix-functions/vfprintf.texi (vfprintf): * doc/posix-functions/vprintf.texi (vprintf): * doc/posix-functions/vsnprintf.texi (vsnprintf): * doc/posix-functions/vsprintf.texi (vsprintf): Document this. * m4/isfinite.m4 (gl_ISFINITEL_WORKS): * m4/isinf.m4 (gl_ISINFL_WORKS): * m4/isnanl.m4 (gl_FUNC_ISNANL_WORKS): * m4/printf.m4 (gl_PRINTF_INFINITE_LONG_DOUBLE): * tests/test-isfinite.c (test_isfinitel): * tests/test-isinf.c (test_isinfl): * tests/test-isnan.c (test_long_double): * tests/test-isnanl.h (main): * tests/test-snprintf-posix.h (test_function): * tests/test-sprintf-posix.h (test_function): * tests/test-vasnprintf-posix.c (test_function): * tests/test-vasprintf-posix.c (test_function): o Test only that noncanonical values do not cause crashes, not that they are treated as NaNs. In some cases this means a larger output buffer is needed.

@node isinf
@section @code{isinf}
@findex isinf

POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/isinf.html}

Gnulib module: isinf

Portability problems fixed by Gnulib:
@itemize
@item
This macro is missing on some platforms:
AIX 5.1, IRIX 6.5, OSF/1 5.1, Solaris 11 2011-11.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
This macro returns an unspecified result when given noncanonical values
such as unnormalized numbers, pseudo-denormals, pseudo-NaNs,
pseudo-Infinities, and pseudo-zeroes.
@end itemize