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 llvm {
22namespace PBQP {
23
24  /// \brief Represents a solution to a PBQP problem.
25  ///
26  /// To get the selection for each node in the problem use the getSelection method.
27  class Solution {
28  private:
29
30    typedef std::map<GraphBase::NodeId, unsigned> SelectionsMap;
31    SelectionsMap selections;
32
33    unsigned r0Reductions, r1Reductions, r2Reductions, rNReductions;
34
35  public:
36
37    /// \brief Initialise an empty solution.
38    Solution()
39      : r0Reductions(0), r1Reductions(0), r2Reductions(0), rNReductions(0) {}
40
41    /// \brief Number of nodes for which selections have been made.
42    /// @return Number of nodes for which selections have been made.
43    unsigned numNodes() const { return selections.size(); }
44
45    /// \brief Records a reduction via the R0 rule. Should be called from the
46    ///        solver only.
47    void recordR0() { ++r0Reductions; }
48
49    /// \brief Returns the number of R0 reductions applied to solve the problem.
50    unsigned numR0Reductions() const { return r0Reductions; }
51
52    /// \brief Records a reduction via the R1 rule. Should be called from the
53    ///        solver only.
54    void recordR1() { ++r1Reductions; }
55
56    /// \brief Returns the number of R1 reductions applied to solve the problem.
57    unsigned numR1Reductions() const { return r1Reductions; }
58
59    /// \brief Records a reduction via the R2 rule. Should be called from the
60    ///        solver only.
61    void recordR2() { ++r2Reductions; }
62
63    /// \brief Returns the number of R2 reductions applied to solve the problem.
64    unsigned numR2Reductions() const { return r2Reductions; }
65
66    /// \brief Records a reduction via the RN rule. Should be called from the
67    ///        solver only.
68    void recordRN() { ++ rNReductions; }
69
70    /// \brief Returns the number of RN reductions applied to solve the problem.
71    unsigned numRNReductions() const { return rNReductions; }
72
73    /// \brief Set the selection for a given node.
74    /// @param nodeId Node id.
75    /// @param selection Selection for nodeId.
76    void setSelection(GraphBase::NodeId nodeId, unsigned selection) {
77      selections[nodeId] = selection;
78    }
79
80    /// \brief Get a node's selection.
81    /// @param nodeId Node id.
82    /// @return The selection for nodeId;
83    unsigned getSelection(GraphBase::NodeId nodeId) const {
84      SelectionsMap::const_iterator sItr = selections.find(nodeId);
85      assert(sItr != selections.end() && "No selection for node.");
86      return sItr->second;
87    }
88
89  };
90
91} // namespace PBQP
92} // namespace llvm
93
94#endif // LLVM_CODEGEN_PBQP_SOLUTION_H
95