Module: ppl/ppl Branch: sparse_matrices Commit: d117160799a3174cd12c8d24a7d8ba378569f17b URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=d117160799a31...

Author: Marco Poletti poletti.marco@gmail.com Date: Mon Mar 22 13:32:36 2010 +0100

MIP_Problem: optimize find_create() calls in linear_combine() (#2).

---

src/MIP_Problem.cc | 33 ++++++++++++--------------------- 1 files changed, 12 insertions(+), 21 deletions(-)

diff --git a/src/MIP_Problem.cc b/src/MIP_Problem.cc index 95ef74a..7b42739 100644 --- a/src/MIP_Problem.cc +++ b/src/MIP_Problem.cc @@ -1333,13 +1333,10 @@ PPL::MIP_Problem::linear_combine(matrix_row_reference_type x, while ((i != i_end) && (j != j_end)) { if (j->first < i->first) { if (j->first != k) { - // FIXME: check if adding "if (j->second != 0)" speeds this up. - itr = x.find_create(j->first); + // The following statements are equivalent to + // sub_mul_assign(x[j->first], j->second, normalized_row_k); + itr = x.find_create(*j); Coefficient& x_i = (*itr).second; - PPL_ASSERT(x_i == 0); - - // sub_mul_assign(x_i, j->second, normalized_row_k); - x_i = j->second; x_i *= normalized_row_k; neg_assign(x_i);

@@ -1369,12 +1366,10 @@ PPL::MIP_Problem::linear_combine(matrix_row_reference_type x, while ((i != i_end) && (j != j_end)) { if (j->first < i->first) { if (j->first != k) { - // FIXME: check if adding "if (j->second != 0)" speeds this up. - itr = x.find_create(j->first, itr); + // The following statements are equivalent to + // sub_mul_assign(x[j->first], j->second, normalized_row_k); + itr = x.find_create(*j,itr); Coefficient& x_i = (*itr).second; - PPL_ASSERT(x_i == 0); - // sub_mul_assign(x_i, j->second, normalized_row_k); - x_i = j->second; x_i *= normalized_row_k; neg_assign(x_i); } @@ -1420,12 +1415,10 @@ PPL::MIP_Problem::linear_combine(matrix_row_reference_type x, if (itr == x.end()) { while (j != j_end) { if (j->first != k) { - // FIXME: check if adding "if (j->second != 0)" speeds this up. - itr = x.find_create(j->first); + // The following statements are equivalent to + // sub_mul_assign(x[j->first], j->second, normalized_row_k); + itr = x.find_create(*j); Coefficient& x_i = (*itr).second; - PPL_ASSERT(x_i == 0); - // sub_mul_assign(x_i, j->second, normalized_row_k); - x_i = j->second; x_i *= normalized_row_k; neg_assign(x_i);

@@ -1439,12 +1432,10 @@ PPL::MIP_Problem::linear_combine(matrix_row_reference_type x, } while (j != j_end) { if (j->first != k) { - // FIXME: check if adding "if (j->second != 0)" speeds this up. - itr = x.find_create(j->first,itr); + // The following statements are equivalent to + // sub_mul_assign(x[j->first], j->second, normalized_row_k); + itr = x.find_create(*j); Coefficient& x_i = (*itr).second; - PPL_ASSERT(x_i == 0); - // sub_mul_assign(x_i, j->second, normalized_row_k); - x_i = j->second; x_i *= normalized_row_k; neg_assign(x_i); }