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options.cpp
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3  * Main authors:
4  * Christian Schulte <schulte@gecode.org>
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7  * Christian Schulte, 2008
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33 
34 #include <gecode/search.hh>
35 
36 #include <cmath>
37 
38 namespace Gecode { namespace Search {
39 
40  const Options Options::def;
41 
42  Options
43  Options::expand(void) const {
44 #ifdef GECODE_HAS_THREADS
45  double t = threads;
46  if (t <= -1.0) {
47  t = Support::Thread::npu() + t;
48  } else if (t < 0.0) {
49  t = (1.0 + t) * Support::Thread::npu();
50  } else if (t == 0.0) {
52  } else if (t < 1.0) {
53  t = t * Support::Thread::npu();
54  }
55  t = floor(t+0.5);
56  if (t < 1.0)
57  t = 1.0;
58  Options o(*this);
59  o.threads = t;
60  return o;
61 #else
62  return *this;
63 #endif
64  }
65 
66 }}
67 
68 // STATISTICS: search-other
NodeType t
Type of node.
Definition: bool-expr.cpp:230
Search engine options
Definition: search.hh:746
static const Options def
Default options.
Definition: search.hh:771
Options expand(void) const
Expand with real number of threads.
Definition: options.cpp:43
double threads
Number of threads to use.
Definition: search.hh:751
static unsigned int npu(void)
Return number of processing units (1 if information not available)
Definition: none.hpp:76