[PPL-devel] [GIT] ppl/ppl(sparse_matrices): PIP_Tree: optimize static function merge_assign() for sparse matrices.

[Marco Poletti]

Module: ppl/ppl
Branch: sparse_matrices
Commit: 11194ae3cfe869768989cd1b1f6b10d92483758b
URL:    http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=11194ae3cfe869768989cd1b1f6b10d92483758b

Author: Marco Poletti <poletti.marco at gmail.com>
Date:   Tue Mar  9 13:48:25 2010 +0100

PIP_Tree: optimize static function merge_assign() for sparse matrices.

---

 src/PIP_Tree.cc |   23 +++++++++++++++++++++--
 1 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/PIP_Tree.cc b/src/PIP_Tree.cc
index 9137180..c14f369 100644
--- a/src/PIP_Tree.cc
+++ b/src/PIP_Tree.cc
@@ -172,14 +172,33 @@ merge_assign(PIP_Tree_Node::matrix_type& x,
          y_end = y.end(); y_i != y_end; ++y_i, ++i) {
     PPL_ASSERT(y_i->is_nonstrict_inequality());
     PIP_Tree_Node::matrix_row_reference_type x_i = x[i];
-    x_i[0] = y_i->inhomogeneous_term();
+    const Coefficient& inhomogeneous_term = y_i->inhomogeneous_term();
+    if (inhomogeneous_term != 0)
+      x_i[0] = inhomogeneous_term;
     Variables_Set::const_iterator pj;
     dimension_type j = 1;
+    PIP_Tree_Node::matrix_row_iterator last = x_i.begin();
     for (pj = param_begin; pj != param_end; ++pj, ++j) {
       Variable vj(*pj);
       if (vj.space_dimension() > cs_space_dim)
         break;
-      x_i[j] = y_i->coefficient(vj);
+      const Coefficient& c = y_i->coefficient(vj);
+      if (c != 0) {
+        last = x_i.find_create(j,c);
+        ++pj;
+        ++j;
+        break;
+      }
+    }
+    for ( ; pj != param_end; ++pj, ++j) {
+      Variable vj(*pj);
+      if (vj.space_dimension() > cs_space_dim)
+        break;
+      const Coefficient& c = y_i->coefficient(vj);
+      if (c != 0) {
+        last = x_i.find_create(j,c,last);
+        break;
+      }
     }
   }
 }