Module: ppl/ppl Branch: pip Commit: 6864f73b1fba0f6029af61fd5fce662f661d2f31 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=6864f73b1fba0...
Author: Enea Zaffanella zaffanella@cs.unipr.it Date: Sat Jan 30 23:38:59 2010 +0100
Minor readability improvements to row_normalize.
---
src/PIP_Tree.cc | 39 ++++++++++++++++++++------------------- 1 files changed, 20 insertions(+), 19 deletions(-)
diff --git a/src/PIP_Tree.cc b/src/PIP_Tree.cc index 7d6781b..2460bf5 100644 --- a/src/PIP_Tree.cc +++ b/src/PIP_Tree.cc @@ -193,35 +193,35 @@ find_lexico_minimum_column(const Matrix& tableau, const std::vector<dimension_type>& mapping, const std::vector<bool>& basis, const Row& pivot_row, - dimension_type start_j, - dimension_type& j) { - dimension_type num_cols = tableau.num_columns(); + const dimension_type start_j, + dimension_type& j_out) { + const dimension_type num_cols = tableau.num_columns(); bool has_positive_coefficient = false;
- j = num_cols; - for (dimension_type j_ = start_j; j_ < num_cols; ++j_) { - const Coefficient& c = pivot_row[j_]; + j_out = num_cols; + for (dimension_type j = start_j; j < num_cols; ++j) { + const Coefficient& c = pivot_row[j]; if (c <= 0) continue; has_positive_coefficient = true; - if (j == num_cols - || column_lower(tableau, mapping, basis, pivot_row, j_, pivot_row, j)) - j = j_; + if (j_out == num_cols + || column_lower(tableau, mapping, basis, + pivot_row, j, pivot_row, j_out)) + j_out = j; } return has_positive_coefficient; }
// Divide all coefficients in row x and denominator y by their GCD. void -row_normalize(Row& x, Coefficient& y) { - if (y == 1) +row_normalize(Row& x, Coefficient& den) { + if (den == 1) return; - dimension_type size = x.size(); - dimension_type j; + const dimension_type x_size = x.size(); PPL_DIRTY_TEMP_COEFFICIENT(gcd); - gcd = y; - for (j=0; j<size; ++j) { - const Coefficient& c = x[j]; + gcd = den; + for (dimension_type i = x_size; i-- > 0; ) { + const Coefficient& c = x[i]; if (c != 0) { gcd_assign(gcd, c, gcd); if (gcd == 1) @@ -229,11 +229,12 @@ row_normalize(Row& x, Coefficient& y) { } } // Divide the coefficients by the GCD. - exact_div_assign(y, y, gcd); - for (j=0; j<size; ++j) { - Coefficient& c = x[j]; + for (dimension_type i = x_size; i-- > 0; ) { + Coefficient& c = x[i]; exact_div_assign(c, c, gcd); } + // Divide the denominator by the GCD. + exact_div_assign(den, den, gcd); }
} // namespace