Problems with GAMMA functions?

[Jerry DeLisle]

Thomas Koenig wrote:
> On Mon, 2007-10-08 at 13:28 +0200, Angelo Graziosi wrote:
> 
>> I have tried the test gfc_gamma_test_c302m.F
>> (http://gcc.gnu.org/ml/fortran/2007-10/msg00096.html) on GNU/Linux kubuntu
>> Feisty 7.04 with GFortran 20071008-129121 and it still fails:
> 
> We are now using the gamma functions provided by the respective
> C libraries.  Looking at the gcc-testresults failures, and at
> your report, it seems as if the quality of existing gamma functions
> is rather low.
> 
> At the least, we should
> 
> - relax the tolerances in gamma_5.f90 to something that doesn't fail
>   on as many systems
> 
> - note in the documentation that the GAMMA functions are sometimes
>   inaccurate, and people may be better off using an external
>   gamma function.
> 
> Maybe we should also provide our own, higher-quality gamma function,
> but I don't see that in the 4.3 timeframe (not if I have to do
> it, at least :-)
> 
> 	Thomas
> 
> 
The test case is failing for me on x86-64-Gnu-linux.  I suspect it is tolerance 
as you suggest.

Jerry