Module: ppl/ppl Branch: master Commit: b67af6c1ba5a560e2ab48a37cccf8fc18782a257 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=b67af6c1ba5a5...
Author: Enea Zaffanella zaffanella@cs.unipr.it Date: Sat Dec 3 09:17:12 2011 +0100
Corrected errors in method Grid::relation_with(const Constraint&) const.
The method was affected by two problems: 1) when working on a non-minimized grid generator system, the points after the first one were transformed into parameters that were not satisfying the Grid_Generator invariant (reported by Marco Poletti); 2) the method was providing an incorrect result when comparing a grid generator line/parameter with a (strict) inequality constraint, as happens for test20() in tests/Grid/relations3.cc.
---
src/Grid_public.cc | 75 ++++++++++++++++++++++++++++++++-------------------- 1 files changed, 46 insertions(+), 29 deletions(-)
diff --git a/src/Grid_public.cc b/src/Grid_public.cc index e05731c..85b3566 100644 --- a/src/Grid_public.cc +++ b/src/Grid_public.cc @@ -623,53 +623,70 @@ PPL::Grid::relation_with(const Constraint& c) const {
bool point_is_included = false; bool point_saturates = false; - const Grid_Generator* first_point = NULL; - - for (Grid_Generator_System::const_iterator g = gen_sys.begin(), - gen_sys_end = gen_sys.end(); g != gen_sys_end; ++g) - switch (g->type()) { + const Grid_Generator* first_point = 0;
+ for (Grid_Generator_System::const_iterator i = gen_sys.begin(), + i_end = gen_sys.end(); i != i_end; ++i) { + const Grid_Generator& g = *i; + switch (g.type()) { case Grid_Generator::POINT: { - Grid_Generator& gen = const_cast<Grid_Generator&>(*g); - if (first_point == NULL) { - first_point = &gen; - const int sign = Scalar_Products::sign(c, gen); - Constraint::Type type = c.type(); - if ((type == Constraint::NONSTRICT_INEQUALITY && sign == 0)) { - point_saturates = true; - } + if (first_point == 0) { + first_point = &g; + const int sign = Scalar_Products::sign(c, g); + if (sign == 0) + point_saturates = !c.is_strict_inequality(); else if (sign > 0) - point_is_included = true; + point_is_included = !c.is_equality(); break; } - // Else convert g to a parameter, and continue into the - // parameter case. + // Not the first point: convert `g' to be a parameter ... + Grid_Generator& gen = const_cast<Grid_Generator&>(g); + const Grid_Generator& point = *first_point; + const Coefficient& p_div = g[0]; + if (p_div != Coefficient_one()) { + for (dimension_type j = gen.size() - 1; j-- > 1; ) + gen[j] *= p_div; + } + const Coefficient& g_div = gen[0]; + if (g_div == Coefficient_one()) { + for (dimension_type j = gen.size() - 1; j-- > 1; ) + gen[j] -= point[j]; + } + else { + for (dimension_type j = gen.size() - 1; j-- > 1; ) + sub_mul_assign(gen[j], g_div, point[j]); + } + gen[0] *= p_div; + gen.strong_normalize(); gen.set_is_parameter(); - const Grid_Generator& first = *first_point; - for (dimension_type i = gen.size() - 1; i-- > 0; ) - gen[i] -= first[i]; + PPL_ASSERT(gen.OK()); + // ... and fall through into the parameter case. }
case Grid_Generator::PARAMETER: case Grid_Generator::LINE: - Grid_Generator& gen = const_cast<Grid_Generator&>(*g); - if (gen.is_line_or_parameter()) - for (dimension_type i = c.space_dimension(); i-- > 0; ) { - Variable v(i); - if (c.coefficient(v) != 0 && gen.coefficient(v) != 0) - return Poly_Con_Relation::strictly_intersects(); - } + { + const int sign = c.is_strict_inequality() + ? Scalar_Products::reduced_sign(c, g) + : Scalar_Products::sign(c, g); + if (sign != 0) + return Poly_Con_Relation::strictly_intersects(); + } break; - } + } // switch + }
+ // If this program point is reached, then all lines and parameters + // saturate the constraint. Hence, the result is determined by + // the previosly computed relation with the point. if (point_saturates) - // Any parameters and lines are also included. return Poly_Con_Relation::saturates() && Poly_Con_Relation::is_included(); + if (point_is_included) - // Any parameters and lines are also included. return Poly_Con_Relation::is_included(); + return Poly_Con_Relation::is_disjoint(); }