weird error in gsl_ran_discrete

[James Theiler <jt@nis.lanl.gov>]

On Sat, 20 Feb 1999, James Theiler wrote:

] On Sat, 20 Feb 1999, James Theiler wrote:
] 
] ] When I ran 'make check', all tests passed except for some of the ...
] 
] Hi again,
] I looked over the tests and realized that 'make check' doesn't check
] either the rng or the randist directories.  maybe that's on purpose.
] Anyway, when I do 'make check' in those directories, I find that
]   rng:     all tests PASS
]   randist: all tests PASS, except two cases for gsl_ran_discrete (whoa!
]            that's my code; i thought i'd checked that...)
] 
] If I can find the problem, I'll check in a patch forthwith.
] 

I give up.

If I ifdef-out all the tests in test.c that preceed
testMoments(FUNC(discrete), ...), or even just move those tests to
the beginning of the list, then the tests pass.

Or, if I compile discrete.c using only CFLAGS=-g, (not using -O2), and
then 'make check', everything works fine. 

Seems to me that it is either some subtle memory allocation bug, or
possibly even a flaw in the compiler.  (I'm using gcc --version=2.8.1)
I actually saw something like this on my Linux box when I was developing
this code; it wasn't this GSL incarnation but an earlier one; again, 
it worked if CFLAGS=-g but failed with CFLAGS='-g -O2'.  When I tried
it using egcs instead of gcc, then it worked fine.

Wish I had time to follow this one up...

regards,
jt

---------------------------------------------
James Theiler                     jt@lanl.gov
MS-D436, NIS-2, LANL        tel: 505/665-5682
Los Alamos, NM 87545        fax: 505/665-4414
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