[Boost-commit] svn:boost r52297 - trunk/boost/graph

Subject: [Boost-commit] svn:boost r52297 - trunk/boost/graph
From: jewillco_at_[hidden]
Date: 2009-04-09 11:41:40

Author: jewillco
Date: 2009-04-09 11:41:38 EDT (Thu, 09 Apr 2009)
New Revision: 52297
URL: http://svn.boost.org/trac/boost/changeset/52297

Log:
Fixed use of undefined function log2
Text files modified: 
   trunk/boost/graph/rmat_graph_generator.hpp |    16 ++++++++++++----                        
   1 files changed, 12 insertions(+), 4 deletions(-)

Modified: trunk/boost/graph/rmat_graph_generator.hpp
==============================================================================
--- trunk/boost/graph/rmat_graph_generator.hpp	(original)
+++ trunk/boost/graph/rmat_graph_generator.hpp	2009-04-09 11:41:38 EDT (Thu, 09 Apr 2009)
@@ -24,6 +24,14 @@
 using boost::shared_ptr;
 using boost::uniform_01;
 
+// Returns floor(log_2(n)), and -1 when n is 0
+template <typename IntegerType>
+inline int int_log2(IntegerType n) {
+  int l = 0;
+  while (n > 0) {++l; n >>= 1;}
+  return l - 1;
+}
+
 struct keep_all_edges {
   template <typename T>
   bool operator()(const T&, const T&) { return true; }
@@ -137,7 +145,7 @@
                   double d, bool permute_vertices = true)
       : gen(), n(n), a(a), b(b), c(c), d(d), edge(m), 
         permute_vertices(permute_vertices), 
-        SCALE(int(floor(log2(n))))
+        SCALE(int_log2(n))
               
     {
       this->gen.reset(new uniform_01<RandomGenerator>(gen));
@@ -261,7 +269,7 @@
         generate_permutation_vector(gen, vertexPermutation, n);
       
       // TODO: "Clip and flip" if undirected graph
-      int SCALE = int(floor(log2(n)));
+      int SCALE = int_log2(n);
       
       for (int i = 0; i < m; ++i) {
 
@@ -361,7 +369,7 @@
       if (permute_vertices) 
         generate_permutation_vector(gen, vertexPermutation, n);
 
-      int SCALE = int(floor(log2(n)));
+      int SCALE = int_log2(n);
       
       std::map<value_type, bool> edge_map;
 
@@ -474,7 +482,7 @@
       if (permute_vertices)
         generate_permutation_vector(gen, vertexPermutation, n);
 
-      int SCALE = int(floor(log2(n)));
+      int SCALE = int_log2(n);
       
       std::map<value_type, bool> edge_map;