1//===-- Solution.h ------- PBQP Solution ------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// PBQP Solution class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CODEGEN_PBQP_SOLUTION_H
15#define LLVM_CODEGEN_PBQP_SOLUTION_H
16
17#include "Graph.h"
18#include "Math.h"
19#include <map>
20
21namespace PBQP {
22
23  /// \brief Represents a solution to a PBQP problem.
24  ///
25  /// To get the selection for each node in the problem use the getSelection method.
26  class Solution {
27  private:
28
29    typedef std::map<GraphBase::NodeId, unsigned> SelectionsMap;
30    SelectionsMap selections;
31
32    unsigned r0Reductions, r1Reductions, r2Reductions, rNReductions;
33
34  public:
35
36    /// \brief Initialise an empty solution.
37    Solution()
38      : r0Reductions(0), r1Reductions(0), r2Reductions(0), rNReductions(0) {}
39
40    /// \brief Number of nodes for which selections have been made.
41    /// @return Number of nodes for which selections have been made.
42    unsigned numNodes() const { return selections.size(); }
43
44    /// \brief Records a reduction via the R0 rule. Should be called from the
45    ///        solver only.
46    void recordR0() { ++r0Reductions; }
47
48    /// \brief Returns the number of R0 reductions applied to solve the problem.
49    unsigned numR0Reductions() const { return r0Reductions; }
50
51    /// \brief Records a reduction via the R1 rule. Should be called from the
52    ///        solver only.
53    void recordR1() { ++r1Reductions; }
54
55    /// \brief Returns the number of R1 reductions applied to solve the problem.
56    unsigned numR1Reductions() const { return r1Reductions; }
57
58    /// \brief Records a reduction via the R2 rule. Should be called from the
59    ///        solver only.
60    void recordR2() { ++r2Reductions; }
61
62    /// \brief Returns the number of R2 reductions applied to solve the problem.
63    unsigned numR2Reductions() const { return r2Reductions; }
64
65    /// \brief Records a reduction via the RN rule. Should be called from the
66    ///        solver only.
67    void recordRN() { ++ rNReductions; }
68
69    /// \brief Returns the number of RN reductions applied to solve the problem.
70    unsigned numRNReductions() const { return rNReductions; }
71
72    /// \brief Set the selection for a given node.
73    /// @param nodeId Node id.
74    /// @param selection Selection for nodeId.
75    void setSelection(GraphBase::NodeId nodeId, unsigned selection) {
76      selections[nodeId] = selection;
77    }
78
79    /// \brief Get a node's selection.
80    /// @param nodeId Node id.
81    /// @return The selection for nodeId;
82    unsigned getSelection(GraphBase::NodeId nodeId) const {
83      SelectionsMap::const_iterator sItr = selections.find(nodeId);
84      assert(sItr != selections.end() && "No selection for node.");
85      return sItr->second;
86    }
87
88  };
89
90}
91
92#endif // LLVM_CODEGEN_PBQP_SOLUTION_H
93