[PURRS-devel] Re: Apparent non-termination of NTL's `make check' (version 5.3.2)

Roberto Bagnara bagnara at cs.unipr.it
Sun Jul 4 17:57:44 CEST 2004


victor shoup wrote:
> I just thought of one other thing to try.
> Recompile everything with -O2, but ./configure with NTL_CLEAN_INT=on 
> NTL_CLEAN_PTR=on
> To be honest, I'd be surprised if this worked, but if it does, that 
> would be very interesting to me.
> These flags are supposed to avoid some code sequences that make 
> assumptions that go
> beyond the language standard (but which seem to be universally 
> implemented).

No, compiling with these flags does not eliminate the infinite loop.

> Some other things to investigate:  are the problems ONLY with the subset 
> program?

Yes.

> Finally, I guess one should try compiling with -g -O2, and run the 
> subset program in gdb,
> force it to quit when its in an infinite loop, and get a backtrace...now 
> that I think of it, I guess this is
> the first thing one should really try!

Yes, it seems to loop around here:

Program received signal SIGINT, Interrupt.
BKZ_FP (BB=@0xbfffd740, UU=0x0, delta=0.98999999999999999, beta=20, prune=10,
     check=0x8049640 <SubsetSumSolution(NTL::vec_ZZ const&)>) at LLL_FP.c:1505
1505                      for (i = jj; i <= kk; i++) {
(gdb) info stack
#0  BKZ_FP (BB=@0xbfffd740, UU=0x0, delta=0.98999999999999999, beta=20,
     prune=10, check=0x8049640 <SubsetSumSolution(NTL::vec_ZZ const&)>)
     at LLL_FP.c:1505
#1  0x08049fa1 in main () at subset.c:111
(gdb)

All the best,

     Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it



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