Bug with LLR !! - Page 3

ATH · 2010-01-11, 21:47

Quote:

Originally Posted by T.Rex

Yes. But Jean is not very talkative ! I think he is working hard on a new version of LLR. Maybe that the problems we have led him to investigate and improve LLR.

BTW, now I've found 5 exponents that generate random Residues through LLR. More are to come, I guess.

One of these days, I'll provide exponent examples. For now, my colleagues and myself keep that confidential.

Tony

Did you test any of the 5 in Prime95?

Kosmaj · 2010-01-11, 21:49

It will be nice to provide k/n pairs of tests producing wrong residues, so that we can test various versions of LLR on respective hardware. Why the secrecy? We have been uncovering bugs in LLR since 2005, always providing concrete k/n numerical values.

Thanks.

T.Rex · 2010-01-11, 22:12

Quote:

Originally Posted by ATH

Did you test any of the 5 in Prime95?

No. Jean is using the Vrba-Reix PRP test for Wagstaff numbers. How could I do a test on such a number with Prime95 ?
Tony

ATH · 2010-01-11, 23:10

Quote:

Originally Posted by T.Rex

No. Jean is using the Vrba-Reix PRP test for Wagstaff numbers. How could I do a test on such a number with Prime95 ?
Tony

Vrba-Reix PRP test also use Prime95 gwnum code right? So it *could* be a bug in gwnum. You can test one of the 5 numbers in Prime95 PRP test. In worktodo.txt:
PRP=1,2,<exponent>,1,0,0,"3"

Then test again on another machine and see if the residues match.

jrk · 2010-01-12, 01:28

Quote:

Originally Posted by T.Rex

BTW, now I've found 5 exponents that generate random Residues through LLR. More are to come, I guess.

I'd guess that it is some sort of memory access problem (overflow, out-of-bounds array, etc) causing the random numbers to appear.

Quote:

Originally Posted by T.Rex

One of these days, I'll provide exponent examples. For now, my colleagues and myself keep that confidential.

So if you want to do all the experimenting for yourself, you should try running LLR with Valgrind to see if there is a memory access problem. Or I'm sure others here would like to, if you don't. But please give your results here if you find something interesting.

T.Rex · 2010-01-12, 14:13

Quote:

Originally Posted by ATH

Vrba-Reix PRP test also use Prime95 gwnum code right? So it *could* be a bug in gwnum. You can test one of the 5 numbers in Prime95 PRP test. In worktodo.txt:
PRP=1,2,<exponent>,1,0,0,"3"

Then test again on another machine and see if the residues match.

We do not know yet if it is a HW or SW problem. There are today 11 exponents with random residues and possibly at least 500 unsure exposants.
We are doing comparison with AMD HW.
Then, we'll see if it is SW.
T.

T.Rex · 2010-01-12, 14:15

Quote:

Originally Posted by jrk

I'd guess that it is some sort of memory access problem (overflow, out-of-bounds array, etc) causing the random numbers to appear.

Yes...

Quote:

So if you want to do all the experimenting for yourself, you should try running LLR with Valgrind to see if there is a memory access problem. Or I'm sure others here would like to, if you don't. But please give your results here if you find something interesting.

I'll first get some fresh news from Jean, in order to know if he is making progress on his side. I've used Valgrind in the past, 3 or 4 years ago !!
T.

Cruelty · 2010-01-12, 18:16

The LLR page you are referring to is different to what I use as reference: http://jpenne.free.fr/. Also, as I don't see version 3.7.2, can you tell me which version exactly were you using?

ATH · 2010-01-12, 20:05

Quote:

Originally Posted by Cruelty

The LLR page you are referring to is different to what I use as reference: http://jpenne.free.fr/. Also, as I don't see version 3.7.2, can you tell me which version exactly were you using?

http://jpenne.free.fr/Development/

T.Rex · 2010-01-16, 22:50

Jean (Penné) is soon to deliver a new version of LLR that fixes the bug we found. The bug was in the old version of gwnum used by LLR. Jean will use a fresh version of gwnum. Now, he also uses the random-switch technic for Vrba-Test !
Seems that the problem is fixed.
And it seems that only 4348 Wagstaff exponents produced a bad residue with LLR 7.3.2 . To be retested...
Tony

Cruelty · 2010-01-16, 23:02

On the development page I can see the 3.80 version dated 14-th of January - anyone tried it already?

2010-01-16, 22:50	#32
T.Rex Feb 2004 France 1624₈ Posts	New LLR version Jean (Penné) is soon to deliver a new version of LLR that fixes the bug we found. The bug was in the old version of gwnum used by LLR. Jean will use a fresh version of gwnum. Now, he also uses the random-switch technic for Vrba-Test ! Seems that the problem is fixed. And it seems that only 4348 Wagstaff exponents produced a bad residue with LLR 7.3.2 . To be retested... Tony

2010-01-11, 21:49	#24
Kosmaj Nov 2003 E26₁₆ Posts	It will be nice to provide k/n pairs of tests producing wrong residues, so that we can test various versions of LLR on respective hardware. Why the secrecy? We have been uncovering bugs in LLR since 2005, always providing concrete k/n numerical values. Thanks.

2010-01-12, 18:16	#30
Cruelty May 2005 2³×7×29 Posts	The LLR page you are referring to is different to what I use as reference: http://jpenne.free.fr/. Also, as I don't see version 3.7.2, can you tell me which version exactly were you using?

2010-01-16, 23:02	#33
Cruelty May 2005 2³·7·29 Posts	On the development page I can see the 3.80 version dated 14-th of January - anyone tried it already?