From: Josh Huber <huberj@wpi.edu>
To: Linux/PowerPC Devel List <linuxppc-dev@lists.linuxppc.org>
Subject: gcc bug
Date: Fri, 31 Mar 2000 09:27:07 -0500 [thread overview]
Message-ID: <20000331092707.C354@wpi.edu> (raw)
Interesting gcc bug here...
in both cases this should print 0xDEADBEEF, but in the second case, garbage
is printed.
main()
{
unsigned long t1 = 32;
unsigned long long t2 = 64;
printf("%x\n", 1 ? 0xDEADBEEF : t1);
printf("%x\n", 1 ? 0xDEADBEEF : t2);
}
as expected, the 1 ? ... operation is optimized away, but the compiler seems
to screw things up ...
working case:
li 4,15
crxor 6,6,6
bl printf
failure case:
li 5,0
li 6,15
crxor 6,6,6
bl printf
in the failure case, r4 is not loaded with anything, so this is were the
garbage probably comes from.
This is a greatly simplified version of an actual piece of code (obviously,
as the code above is silly :)
Josh
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
next reply other threads:[~2000-03-31 14:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-03-31 14:27 Josh Huber [this message]
2000-03-31 15:18 ` gcc bug Gabriel Paubert
-- strict thread matches above, loose matches on Subject: below --
2003-06-18 19:00 David Mosberger
1998-07-10 19:49 GCC bug ralf
1997-07-05 21:09 Ralf Baechle
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