Module: ppl/ppl Branch: sparse_matrices Commit: b392bd331e5331d3fad9a9e359753e3cfcf962c6 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=b392bd331e533...
Author: Marco Poletti poletti.marco@gmail.com Date: Thu Apr 15 18:45:22 2010 +0200
PIP_Problem: optimize solve() for backends with fast random writes.
---
src/PIP_Problem.cc | 25 +++++++++++++++++++++++++ 1 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/src/PIP_Problem.cc b/src/PIP_Problem.cc index fa01e4e..cc9ede9 100644 --- a/src/PIP_Problem.cc +++ b/src/PIP_Problem.cc @@ -159,6 +159,7 @@ PPL::PIP_Problem::solve() const { = x.initial_context[x.initial_context.num_rows()-1];
{ +#ifdef PPL_SPARSE_BACKEND_SLOW_RANDOM_WRITES matrix_row_iterator itr = row.end();
if (c.inhomogeneous_term() != 0) { @@ -202,6 +203,30 @@ PPL::PIP_Problem::solve() const { break; } } +#else // defined(PPL_SPARSE_BACKEND_SLOW_RANDOM_WRITES) + if (c.inhomogeneous_term() != 0) { + Coefficient& row0 = row[0]; + row0 = c.inhomogeneous_term(); + // Adjust inhomogenous term if strict. + if (c.is_strict_inequality()) + --row0; + } else { + // Adjust inhomogenous term if strict. + if (c.is_strict_inequality()) + neg_assign(row[0], Coefficient_one()); + } + dimension_type i = 1; + Variables_Set::const_iterator pi = param_begin; + + for ( ; pi != param_end; ++pi, ++i) { + if (*pi < c_space_dim) { + const Coefficient& x = c.coefficient(Variable(*pi)); + if (x != 0) + row[i] = x; + } else + break; + } +#endif // defined(PPL_SPARSE_BACKEND_SLOW_RANDOM_WRITES) }
// If it is an equality, also insert its negation.