Solution.h revision eb6c8f53b4df1488f3d07c11af8f754cc4620f3a 
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 "Math.h"
18#include "Graph.h"
19
20#include <map>
21
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<Graph::ConstNodeItr, unsigned,
31                     NodeItrComparator> SelectionsMap;
32    SelectionsMap selections;
33
34    unsigned r0Reductions, r1Reductions, r2Reductions, rNReductions;
35
36  public:
37
38    /// \brief Initialise an empty solution.
39    Solution()
40      : r0Reductions(0), r1Reductions(0), r2Reductions(0), rNReductions(0) {}
41
42    /// \brief Number of nodes for which selections have been made.
43    /// @return Number of nodes for which selections have been made.
44    unsigned numNodes() const { return selections.size(); }
45
46    /// \brief Records a reduction via the R0 rule. Should be called from the
47    ///        solver only.
48    void recordR0() { ++r0Reductions; }
49
50    /// \brief Returns the number of R0 reductions applied to solve the problem.
51    unsigned numR0Reductions() const { return r0Reductions; }
52
53    /// \brief Records a reduction via the R1 rule. Should be called from the
54    ///        solver only.
55    void recordR1() { ++r1Reductions; }
56
57    /// \brief Returns the number of R1 reductions applied to solve the problem.
58    unsigned numR1Reductions() const { return r1Reductions; }
59
60    /// \brief Records a reduction via the R2 rule. Should be called from the
61    ///        solver only.
62    void recordR2() { ++r2Reductions; }
63
64    /// \brief Returns the number of R2 reductions applied to solve the problem.
65    unsigned numR2Reductions() const { return r2Reductions; }
66
67    /// \brief Records a reduction via the RN rule. Should be called from the
68    ///        solver only.
69    void recordRN() { ++ rNReductions; }
70
71    /// \brief Returns the number of RN reductions applied to solve the problem.
72    unsigned numRNReductions() const { return rNReductions; }
73
74    /// \brief Set the selection for a given node.
75    /// @param nItr Node iterator.
76    /// @param selection Selection for nItr.
77    void setSelection(Graph::NodeItr nItr, unsigned selection) {
78      selections[nItr] = selection;
79    }
80
81    /// \brief Get a node's selection.
82    /// @param nItr Node iterator.
83    /// @return The selection for nItr;
84    unsigned getSelection(Graph::ConstNodeItr nItr) const {
85      SelectionsMap::const_iterator sItr = selections.find(nItr);
86      assert(sItr != selections.end() && "No selection for node.");
87      return sItr->second;
88    }
89
90  };
91
92}
93
94#endif // LLVM_CODEGEN_PBQP_SOLUTION_H
95