1.5.7 test failure in nbest-optimize-bleu

[Andreas Stolcke]

In message <49087CA2.3030504 at jhu.edu>you wrote:
> Hi,
>   I didn't see anything about this in the mailing-list archive.  I just 
> installed 1.5.7 and ran the
> tests.  I saw one failure, in nbest-optimize-bleu.   I looked at the 
> code briefly; the output is coming from nbest-optimize.cc:1179, but 
> that's about as far as I got.  I built on Mac OS 10.4.11 using
> this compiler version:
> 
> ~/work/srilm--$ c++ --version
> i686-apple-darwin8-g++-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build 5370)
> 
> I can try another system if that will help, or let me know if anyone 
> wants more information.
>     Thanks,
>         Ken Basye
> 

It turns out this problems seems to affect compilation with gcc 4.2 on all
the platforms I tried (Linux, Solaris), so I assume it's the same bug as 
you describe.  The problem has to do with expression evaluation order
when the expression has side effects (++ operator).

You can apply the following patch, or download the beta release
(which also has some other fixes for BLEU optimization).

Andreas

*** lm/src/nbest-optimize.cc	2008/11/07 15:14:15	1.58
--- lm/src/nbest-optimize.cc	2008/11/08 13:49:49	1.59
***************
*** 1176,1182 ****
  		    {
  			if (!fixLambdas[k])
  			    cerr << "lambda_" << j - 1
! 				 << " " << p[ilo][j++] << endl;
  		    }
  		}
  	    }
--- 1176,1183 ----
  		    {
  			if (!fixLambdas[k])
  			    cerr << "lambda_" << j - 1
! 				 << " " << p[ilo][j] << endl;
! 			    j ++;
  		    }
  		}
  	    }