January 2006 - PPL-devel - BUGSENG Mailman

SICStus interface
by Tristan Denmat 17 Mar '06

17 Mar '06

Hi, I am trying to use the interface between PPL and SICStus. Following what is said in the manual, there should be an .pl file in the /bin directory but there is not. Does it mean that I forgot to put a flag or something like this ? Thanks, Tristan Denmat

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Confusion about "space dimension"
by Roberto Bagnara 01 Feb '06

01 Feb '06

Now that the PPL is no longer limited to ordinary convex polyhedra and many new abstractions are finding their way to the library, I believe that the distinction between syntax and semantics is fundamental. According to this view, the PPL would support a set of "syntactic objects" (variables, linear expressions, constraints, congruences, generators, grid-generators, ... and finite systems of such things) and a set of "semantic objects" (polyhedra, grids, bounded-difference shapes, octagons, bounding boxes, ..., powersets of the above, ..., linear programming problems, ...). I think this distinction must be kept as clear as possible. We are already doing it, to some extent, but the fact that some syntactic objects are directly used in the implementation of semantic objects has caused some of our syntactic objects to expose some inner details of their role in the implementation of semantic objects. To clarify, this program #include <ppl.hh> using namespace Parma_Polyhedra_Library; using namespace Parma_Polyhedra_Library::IO_Operators; using namespace std; int main() { Variable x(0); Variable y(1); Variable z(2); Linear_Expression e = x+y+z; cout << e << " has space dimension " << e.space_dimension() << endl; e -= z; cout << e << " has space dimension " << e.space_dimension() << endl; return 0; } prints A + B + C has space dimension 3 A + B has space dimension 3 whereas it should print A + B + C has space dimension 3 A + B has space dimension 2 The same sin is committed by Constraint, Generator and so forth. I believe we should stick to one, unambiguous definition of "space dimension" and be consistent with it throughout the library. We know what "space dimension" is for a semantic object: it is also clearly stated in the documentation. We need to find a similar definition that works for syntactic objects (such as the minimum space dimension for which the object makes sense) or conclude that the notion of "space dimension" should be reserved to semantic objects only and find another name for this other concept. Feedback is welcome on all these points. Ciao, Roberto -- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it

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ppl/sicstus/segmentation violation
by Samir Genaim 01 Feb '06

01 Feb '06

ppl_delete_Polyhedron/1 cause "segmentation violation" when using ppl_sicstus. For example, the following query results in segmentation violation: ?- ppl_initialize, A='$VAR'(0), B='$VAR'(1),ppl_new_NNC_Polyhedron_from_constraints([A>B,B>=A],X),ppl_delete_Polyhedron(X). I am running SICStus "3.10.0 (x86-Linux-glibc2.2)" with ppl-0.8. Note that it works fine in other Prolog, e.g., Ciao. any idea what could be the problem ? Thanks. -- Samir

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Big problems with not-so-big numbers
by Roberto Bagnara 01 Feb '06

01 Feb '06

Below the signature is everything needed to reproduce the problem under GNU/Linux. I have checked the YAP sources, but did not succeed in finding what may cause this behavior. 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@cs.unipr.it $ cat bug.c #include <Yap/YapInterface.h> #include <limits.h> YAP_Bool long_min(YAP_Term t) { return YAP_Unify(t, YAP_MkIntTerm(LONG_MIN)); } YAP_Bool yap_stub_long_min() { YAP_Term arg1 = YAP_A(1); return long_min(arg1); } void init() { YAP_UserCPredicate("long_min", (int(*)())(yap_stub_long_min), 1); } $ gcc -c -shared -fPIC bug.c $ ld -shared -o bug.so bug.o $ yap % Restoring file /usr/local/lib/Yap/startup YAP version Yap-5.1.0 ?- load_foreign_files(['bug'],[],init). yes ?- long_min(M). M = -2147483648 ? yes ?- long_min(M), M == -2147483648. no ?- long_min(M), M = -2147483648. no ?- long_min(M), M is 0 - 2147483648. no ?- long_min(M), M1 is abs(M). M = M1 = -2147483648 ? yes ?- $

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ppl/tests/Grid grid2.cc
by Matthew Mundell 31 Jan '06

31 Jan '06

CVSROOT: /cvs/ppl Module name: ppl Changes by: mundell(a)cs.unipr.it 2006-01-31 19:12:51 Modified files: tests/Grid : grid2.cc Log message: Move variables to a local namespace. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/Grid/grid2.cc.diff?cvsr…

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ppl/tests/Grid grid1.cc
by Matthew Mundell 31 Jan '06

31 Jan '06

CVSROOT: /cvs/ppl Module name: ppl Changes by: mundell(a)cs.unipr.it 2006-01-31 19:12:29 Modified files: tests/Grid : grid1.cc Log message: Ensure that all exception tests emit noisy messages. Move variables to a local namespace. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/Grid/grid1.cc.diff?cvsr…

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ppl/tests/Grid equals1.cc
by Matthew Mundell 31 Jan '06

31 Jan '06

CVSROOT: /cvs/ppl Module name: ppl Changes by: mundell(a)cs.unipr.it 2006-01-31 19:11:26 Modified files: tests/Grid : equals1.cc Log message: Add tests to cover the rest of Grid::quick_equivalence_test(). Move variables to a local namespace. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/Grid/equals1.cc.diff?cv…

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ppl/tests/Grid bounds1.cc
by Matthew Mundell 31 Jan '06

31 Jan '06

CVSROOT: /cvs/ppl Module name: ppl Changes by: mundell(a)cs.unipr.it 2006-01-31 19:09:24 Modified files: tests/Grid : bounds1.cc Log message: Add space dimension exception test. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/Grid/bounds1.cc.diff?cv…

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ppl/tests/Grid relations1.cc join3.cc join1.cc ...
by Matthew Mundell 31 Jan '06

31 Jan '06

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ppl/tests/Grid addcongruences1.cc
by Matthew Mundell 31 Jan '06

31 Jan '06

CVSROOT: /cvs/ppl Module name: ppl Changes by: mundell(a)cs.unipr.it 2006-01-31 19:05:07 Modified files: tests/Grid : addcongruences1.cc Log message: Add tests that exercise the case in minimize() where both systems are up-to-date. Patches: http://www.cs.unipr.it/cgi-bin/cvsweb.cgi/ppl/tests/Grid/addcongruences1.cc…

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