Re: Mac OS X bug in FD solver?

[Conrad Scott]

Dear bug-prolog list,

The problem I posted below is "cured" by reducing the optimization  
level of GCC down to just -O1. I've not had any luck trying to see  
*why* that works but I've now got a working copy of GNU Prolog on my  
laptop, so I'm happy. Still, if someone can suggest how to approach  
debugging this, I'll gladly have a shot.

By the way, I checked right back to the first Darwin port (1.2.13?) and  
the problem is still there.

Best wishes,

// Conrad

On 19 Jul 2004, at 9:04 pm, Conrad Scott wrote:

> Dear bug-prolog list,
>
> I posted an example to the users-prolog list and it seems that it's  
> probably a bug, so I'm posting some more details here.
>
> I'm using Mac OS X.3 (on a G4 system) and I've tried this in both the  
> 1.2.16 release (as downloaded and installed via fink) and also the  
> current 1.2.18 release (downloaded from  
> ftp://ftp.inria.fr/INRIA/Projects/contraintes/gprolog/unstable/ 
> gprolog-20040608.tgz).
>
> I've had a look at the configuration / install for the most recent  
> version and it all seems fine to the untrained eye. The configuration  
> process recognizes the host as Darwin powerpc BSD etc. The output from  
> uname -a and gprolog --version is as follows:
>
>         scottc$ uname -a
> 	Darwin Conrads-Computer.local 7.4.0 Darwin Kernel Version 7.4.0: Wed  
> May 12 16:58:24 PDT 2004; root:xnu/xnu-517.7.7.obj~7/RELEASE_PPC   
> Power Macintosh powerpc
>
>         scottc$ gprolog --version
>         Prolog top-Level (GNU Prolog) 1.2.18
>         By Daniel Diaz
>         Copyright (C) 1999-2004 Daniel Diaz
>         GNU Prolog comes with ABSOLUTELY NO WARRANTY.
>         You may redistribute copies of GNU Prolog
>         under the terms of the GNU General Public License.
>         For more information about these matters, see the files named COPYING.
>
> The smallest test case I've found for the problem is (as I posted in  
> users-prolog):
>
>         | ?- A#=B,fd_domain([A,B],0,1),fd_labeling([A,B]).
>
>         A = 0
>         B = 0 ? a
>
>         A = 1
>         B = 1
>
>         yes
>
> That looks correct to me, but if I re-order the query as follows it  
> doesn't seem right:
>
>         | ?- fd_domain([A,B],0,1),A#=B,fd_labeling([A,B]).
>
>         A = 0
>         B = 0 ? a
>
>         A = 1
>         B = 0
>
>         yes
>
> I'm happy to have a go at debugging this (though I'd need a hint of  
> where to start) or at providing information for someone else to work  
> on it.
>
> Thanks,
>
> // Conrad
>
>
>
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