arch-independent glibc printf segfault for "special" long double values
Jan-Benedict Glaw
jbglaw@lug-owl.de
Fri Jun 8 09:28:00 GMT 2007
On Fri, 2007-06-08 10:48:02 +0200, Jim Meyering <jim@meyering.net> wrote:
> This started with Bruno Haible's bug report:
>
> > printf crashes on some 'long double' values
> > http://sourceware.org/bugzilla/show_bug.cgi?id=4586
>
> I objected to the closure of that BZ:
>
> http://thread.gmane.org/gmane.comp.lib.glibc.alpha/12394
>
> For example, it can cause GNU od to segfault.
[...]
> On x86_64, you need to use -tf16 to get the long double interpretation.
> On an 686-based system, it's a 12-byte quantity, so you need "-tf12".
> Both of these systems are using libc-2.5:
[...]
With -tf16, what binary float representation is used? 754? 854? One of
the VAX formats? IBM? The local representation of a "long double"?
That would even mean that feeding the same bytes into GNU od, you may
get two different results on two different architectures because of
architecture-dependant data parsing?
MfG, JBG
--
Jan-Benedict Glaw jbglaw@lug-owl.de +49-172-7608481
Signature of: 23:53 <@jbglaw> So, ich kletter' jetzt mal ins Bett.
the second : 23:57 <@jever2> .oO( kletter ..., hat er noch Gitter vorm Bett, wie früher meine Kinder?)
00:00 <@jbglaw> jever2: *patsch*
00:01 <@jever2> *aua*, wofür, Gedanken sind frei!
00:02 <@jbglaw> Nee, freie Gedanken, die sind seit 1984 doch aus!
00:03 <@jever2> 1984? ich bin erst seit 1985 verheiratet!
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