David Merchat wrote:
I work with PPL.0.2 [...] I also made some tests with PPL a observed some strange behaviours:
- satisfies with a polyhedron given by vertex allways abord
Exemple : GenSys gs; gs.insert(vertex(1*A + 1*B)); Polyhedron test(gs); ConSys lin; lin.insert(A >= 0); GenSys_Con_Rel rel = test.satisfies(lin[0]); Execution Abort
- calling affine_image can produce a polyhedron which violates
invariants of PPL Exemple ostream& sortie = cout; Polyhedron test(3); test.insert(C == -2); test.insert(A == 0); LinExpression lin = LinExpression(Integer(2)); lin = lin + (Integer(1)*Variable(0)); lin = lin + (Integer(0)*Variable(1)); lin = lin + (Integer(0)*Variable(2)); lin = lin + (Integer(0)*Variable(2)); test.affine_image(Variable(1), lin, 1); if(!test.OK()) sortie << "???" << endl; Execution Poly space_dim 3 -ZE -EM -CM -GM +CS -GS -SC -SG con_sys (up-to-date) 3 x 4 (not_sorted) 1 0 0 0 >= 2 0 0 1 = 0 1 0 0 =
gen_sys (not_up-to-date) 0 x 0 (not_sorted)
sat_c 0 x 0
sat_g 0 x 0
Lin expr 2 1 0 0 Generators must have at least one nonzero homogeneous coefficient! Here is the guilty polyhedron: space_dim 3 -ZE -EM -CM -GM -CS +GS -SC -SG con_sys (not_up-to-date) 3 x 4 (sorted) 2 0 0 1 = 0 1 0 0 = 1 0 0 0 >=
gen_sys (up-to-date) 2 x 4 (not_sorted) 0 0 0 0 L 1 0 2 -2 V
sat_c 0 x 0
sat_g 3 x 2 0 0 0 0 0 1
???
Is there any others known strange behaviours?
Dear David,
the strange behaviors you have identified are indeed bugs and the test programs you included allowed us to find them quickly (they are already solved in the CVS repository). The library is still young and your programs exercised two methods that received little testing so far.
Even though we plan to release PPL version 0.3 in the near future, we are still not ready for that. The most convenient way to solve the problems you encountered would be to use a PPL snapshot: we have just uploaded snapshot 0.3pre4 to our FTP/HTTP site (get it either from ftp://ftp.cs.unipr.it/pub/ppl/snapshots/ or http://www.cs.unipr.it/ppl/Download/ftp/snapshots/).
In this way you would get a version with several other problems solved. There is a drawback though: you would need to upgrade your GMP installation to version 4.0.1 (get it from http://swox.com/gmp/), something that all the PPL 0.3 users will have to do anyway (this brings you other advantages but may be a nuisance).
If you don't want to upgrade to GMP 4.0.1 what you could do is to patch your PPL 0.2 sources: you will find the relevant patches in
http://www.cs.unipr.it/pipermail/ppl-devel/2002-February/001031.html
You may also want to apply the following patch, correcting a bug in the method Polyhedron::remove_higher_dimensions(size_t)
http://www.cs.unipr.it/pipermail/ppl-devel/2002-January/001003.html
I interfaced PPL with one of my programms and i tryed to complie with "purify" (my programm isn't finished and i have some problems of memory management). But it's seem that i can't compile PPL with "purify". So my question is how comple PPL.0.2 with "purify" (if it's possible).
Can you be more specific about the problems you are encountering? We do not have a license for Purify so we do not really know what to say. You could send us the compiler messages so that we can narrow the search down.
Thanks for your answer and for PPL
Glad to be useful. Please do not hesitate to contact us for reporting bugs, making suggestions and sharing your experiences with the library. All the best
the PPL development team