Module: ppl/ppl Branch: pip Commit: 35d2df08098d17c0a57b5df0d9f7f27512d0c5f1 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=35d2df08098d1...

Author: Enea Zaffanella zaffanella@cs.unipr.it Date: Fri Feb 4 09:52:58 2011 +0100

Fully normalize artificial parameters on construction. When in noisy mode, print normalized parameters.

---

src/PIP_Tree.cc | 71 +++++++++++++++++++++++++++++++++++++++++----- src/PIP_Tree.inlines.hh | 17 ----------- 2 files changed, 63 insertions(+), 25 deletions(-)

diff --git a/src/PIP_Tree.cc b/src/PIP_Tree.cc index 8c22a25..b9a818d 100644 --- a/src/PIP_Tree.cc +++ b/src/PIP_Tree.cc @@ -29,6 +29,9 @@ site: http://www.cs.unipr.it/ppl/ . */ #include <memory> #include <map>

+// #define NOISY_PIP +// #define VERY_NOISY_PIP 0 + namespace Parma_Polyhedra_Library {

namespace { @@ -802,6 +805,60 @@ PIP_Tree_Node::PIP_Tree_Node(const PIP_Tree_Node& y) artificial_parameters(y.artificial_parameters) { }

+PIP_Tree_Node::Artificial_Parameter +::Artificial_Parameter(const Linear_Expression& expr, + Coefficient_traits::const_reference den) + : Linear_Expression(expr), denom(den) { + if (denom == 0) + throw std::invalid_argument("PIP_Tree_Node::Artificial_Parameter(e, d): " + "denominator d is zero."); + + // Normalize if needed. + // FIXME: Provide a proper normalization helper. + Linear_Expression& param_expr = *this; + if (denom < 0) { + neg_assign(denom); + param_expr *= -1; + } + + // Compute GCD of parameter expression and denum. + PPL_DIRTY_TEMP_COEFFICIENT(gcd); + gcd = denom; + gcd_assign(gcd, param_expr.inhomogeneous_term(), gcd); + if (gcd == 1) + return; + const dimension_type space_dim = param_expr.space_dimension(); + for (dimension_type i = space_dim; i-- > 0; ) { + Coefficient_traits::const_reference + e_i = param_expr.coefficient(Variable(i)); + if (e_i != 0) { + gcd_assign(gcd, e_i, gcd); + if (gcd == 1) + return; + } + } + + // Divide coefficients and denominator by their (non-trivial) GCD. + PPL_ASSERT(gcd > 1); + Linear_Expression normalized(0 * Variable(space_dim-1)); + PPL_DIRTY_TEMP_COEFFICIENT(coeff); + exact_div_assign(coeff, param_expr.inhomogeneous_term(), gcd); + normalized += coeff; + for (dimension_type i = space_dim; i-- > 0; ) { + Coefficient_traits::const_reference + e_i = param_expr.coefficient(Variable(i)); + if (e_i != 0) { + exact_div_assign(coeff, e_i, gcd); + add_mul_assign(normalized, coeff, Variable(i)); + } + } + // Replace the parameter expression with the normalized one. + param_expr = normalized; + exact_div_assign(denom, denom, gcd); + + PPL_ASSERT(OK()); +} + bool PIP_Tree_Node::Artificial_Parameter ::operator==(const PIP_Tree_Node::Artificial_Parameter& y) const { @@ -2262,11 +2319,11 @@ PIP_Solution_Node::solve(const PIP_Problem& pip, const dimension_type num_params = tableau.t.num_columns(); Coefficient_traits::const_reference tableau_den = tableau.denominator();

-#ifdef NOISY_PIP +#ifdef VERY_NOISY_PIP tableau.ascii_dump(std::cerr); std::cerr << "context "; context.ascii_dump(std::cerr); -#endif +#endif // #ifdef VERY_NOISY_PIP

// (Re-) Compute parameter row signs. // While at it, keep track of the first parameter rows @@ -2407,7 +2464,7 @@ PIP_Solution_Node::solve(const PIP_Problem& pip,

#ifdef NOISY_PIP std::cerr << "Pivot (pi, pj) = (" << pi << ", " << pj << ")\n"; -#endif +#endif // #ifdef NOISY_PIP

// Normalize the tableau before pivoting. tableau.normalize(); @@ -2617,7 +2674,7 @@ PIP_Solution_Node::solve(const PIP_Problem& pip, std::cerr << "Found row (" << i_neg << ") with mixed parameter sign " << "and negative variable coefficients.\n" << "==> adding tautology.\n"; -#endif +#endif // #ifdef NOISY_PIP Row copy = tableau.t[i_neg]; copy.normalize(); context.add_row(copy); @@ -2994,8 +3051,7 @@ PIP_Solution_Node::generate_cut(const dimension_type index, #ifdef NOISY_PIP using namespace IO_Operators; std::cout << "Re-using parameter " << Variable(ap_column) - << " = (" << expr << ")/" << den - << std::endl; + << " = " << ap << std::endl; #endif // #ifdef NOISY_PIP ap_column = ap_column - num_vars + 1; } @@ -3010,8 +3066,7 @@ PIP_Solution_Node::generate_cut(const dimension_type index, using namespace IO_Operators; std::cout << "Creating new parameter " << Variable(space_dimension) - << " = (" << expr << ")/" << den - << std::endl; + << " = " << ap << std::endl; #endif // #ifdef NOISY_PIP ++space_dimension; ap_column = num_params; diff --git a/src/PIP_Tree.inlines.hh b/src/PIP_Tree.inlines.hh index ef0e8e0..ddd1bc0 100644 --- a/src/PIP_Tree.inlines.hh +++ b/src/PIP_Tree.inlines.hh @@ -111,23 +111,6 @@ PIP_Tree_Node::Artificial_Parameter::Artificial_Parameter()

inline PIP_Tree_Node::Artificial_Parameter -::Artificial_Parameter(const Linear_Expression& expr, - Coefficient_traits::const_reference den) - : Linear_Expression(expr), denom(den) { - if (denom == 0) - throw std::invalid_argument("PIP_Tree_Node::Artificial_Parameter(e, d): " - "denominator d is zero."); - // Normalize if needed. - if (denom < 0) { - neg_assign(denom); - Linear_Expression& e = *this; - e *= -1; - } - PPL_ASSERT(OK()); -} - -inline -PIP_Tree_Node::Artificial_Parameter ::Artificial_Parameter(const Artificial_Parameter& y) : Linear_Expression(y), denom(y.denom) { PPL_ASSERT(OK());