GNU bug report logs - #15842
Integer overflow on Mac OS X 64-bit

Previous Next

Full log

Message #13 received at 15842-done <at> debbugs.gnu.org (full text, mbox):

From: Mark H Weaver <mhw <at> netris.org>
To: Geert Janssens <geert <at> kobaltwit.be>
Cc: 15842-done <at> debbugs.gnu.org
Subject: Re: bug#15842: Integer overflow on Mac OS X 64-bit
Date: Thu, 14 Nov 2013 19:25:25 -0500

Geert Janssens <geert <at> kobaltwit.be> writes:
> I am experimenting with swig bindings for guile on Mac OS X. One of the 
> swig tests (the integer test) is failing. I am aware that swig is not 
> guile, but the bug seems to be reproducible in pure guile as well.
>
> When I calculate (2^64) -1 on the Mac OS X platform, it returns -1. On 
> my fedora system, the same calculation returns
> 18446744073709551615

When reporting bugs, please tell us what version of Guile you're using.

This is fixed in Guile 2.0.9.  The bug came into existence when clang
started optimizing out overflow checks, on the theory that if a signed
integer overflow occurs then the behavior is unspecified and thus the
compiler can do whatever it likes.

http://git.savannah.gnu.org/gitweb/?p=guile.git;a=commit;h=2355f01709eadfd5350c510cdb095b4e3f71f17c
http://stackoverflow.com/questions/14495636/strange-multiplication-behavior-in-guile-scheme-interpreter

I'm closing this bug, on the assumption that you're using an old Guile
release.  Please reopen it if the problem still exists in 2.0.9.

    Thanks!
      Mark

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.