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.

1 files changed, 4 insertions, 9 deletions

diff --git a/doc/posix-functions/isnan.texi b/doc/posix-functions/isnan.texi
index 160b7a4627..f9ed11a6b5 100644
--- a/doc/posix-functions/isnan.texi
+++ b/doc/posix-functions/isnan.texi
@@ -19,17 +19,12 @@ on pre-C99 systems.
 IRIX 6.5, OSF/1 5.1 with gcc, Solaris 11 2011-11.
 @item
 On IRIX 6.5 with @code{cc}, @code{isnan} does not recognize some NaNs.
-@item
-On NetBSD/i386 and glibc/ia64, @code{isnan} does not recognize some
-forms of NaNs, such as pseudo-NaNs, pseudo-Infinities, and
-unnormalized numbers.
-@item
-On i686 and @var{x}86-64, @code{__builtin_isnanl} (and thus
-@code{isnan} implementations based on it) in GCC 4.0 and later does
-not recognize pseudo-denormals as NaNs, and similarly for
-pseudo-zeroes, unnormalized numbers, and pseudo-denormals on ia64.
 @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