Profiling bug in 6.10.4

[Gregory Wright]

Hi Krzysztof,

On 3/22/10 2:42 PM, Krzysztof Skrzętnicki wrote:
> I got some results from  GHC 6.12.1, Linux i686. In short: both
> profiling and normal run produce the same final results, but there are
> some differences. I don't know if they are valid or not.
>
> ./nsyn | tail
> 1080826.599  0.01   8.483e-15    7.612e-1    7.753e-5    2.517e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1134406.808  0.01   6.911e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1191190.672  0.01   5.615e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1251481.495  0.01   4.548e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1315638.396  0.01   3.671e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1384093.315  0.01   2.952e-15    7.612e-1    7.753e-5    2.515e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1457375.318  0.01   2.364e-15    7.612e-1    7.753e-5    2.515e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1535826.102  0.01   1.884e-15    7.612e-1    7.753e-5    2.515e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1619603.195  0.01   1.495e-15    7.612e-1    7.753e-5    2.514e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1709306.677  0.01   1.180e-15    7.612e-1    7.753e-5    2.514e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
>
>   ./nsyn-prof | tail
> 1080826.599  0.01   8.483e-15    7.612e-1    7.753e-5    2.517e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1134406.808  0.01   6.911e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1191190.672  0.01   5.615e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1251481.495  0.01   4.548e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1315638.396  0.01   3.671e-15    7.612e-1    7.753e-5    2.516e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1384093.315  0.01   2.952e-15    7.612e-1    7.753e-5    2.515e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1457375.318  0.01   2.364e-15    7.612e-1    7.753e-5    2.515e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1535826.102  0.01   1.884e-15    7.612e-1    7.753e-5    2.515e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1619603.195  0.01   1.495e-15    7.612e-1    7.753e-5    2.514e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
> 1709306.677  0.01   1.180e-15    7.612e-1    7.753e-5    2.514e-7
> 1.566e-5    2.387e-1   3.089e-14   6.337e-11   5.791e-11   5.665e-16
>
> Best regards
>
> Krzysztof Skrzętnicki
>
> 2010/3/22 Gregory Wright<gwright at antiope.com>:
>    
>> Hi,
>>
>> On 3/22/10 10:22 AM, Gregory Wright wrote:
>>      
>>> Hi,
>>>
>>> I have a program (attached) that is relatively simple, but numerically
>>> intensive.
>>> It computes the abundances of the chemical elements generated by big-bang
>>> nucleosynthesis.  At the moment, the executable takes no command line
>>> arguments,
>>> it simply runs the standard model.
>>>
>>> When I build the program without profiling, it produces the right answer.
>>>   When
>>> I build it with profiling (runhaskell configure
>>> --enable-executable-profiling) it runs
>>> without error, but gives completely incorrect numerical results.  I'm
>>> using ghc 6.10.4
>>> built from source using MacPorts.
>>>
>>> The program is mostly self contained, but uses the hmatrix package to
>>> solve a linear
>>> system.  Note also that the "Vector" type is hmatrix's Data.Packed.Vector
>>> and not
>>> the one from the more familiar "vector" package.
>>>
>>> I was wondering whether this profiling problem is known.
>>>
>>> Best Wishes,
>>> Greg
>>>
>>>        
>> The previously attach tarball was missing most of its contents, courtesy
>> of my ham-fisted emacs technique.  The tarball attached to this message has
>> been tested by building and shows the problem mentioned above.
>>
>> -Greg
>>
>>      
>
>    

Now they seem to both be correct.  The key value is at the bottom of 
column 8.  This should be 2.386e-1
(which means that 23.86 percent of the protons in the early universe end 
up as helium).  So it
seems that this is a problem either with 6.10.4, or with OS X.

Quite strange.  I will try to get 6.12 building on my machine to see if 
the problem persists.

-Greg