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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 
22 namespace 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.
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.
numNodes()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.
recordR0()48     void recordR0() { ++r0Reductions; }
49 
50     /// \brief Returns the number of R0 reductions applied to solve the problem.
numR0Reductions()51     unsigned numR0Reductions() const { return r0Reductions; }
52 
53     /// \brief Records a reduction via the R1 rule. Should be called from the
54     ///        solver only.
recordR1()55     void recordR1() { ++r1Reductions; }
56 
57     /// \brief Returns the number of R1 reductions applied to solve the problem.
numR1Reductions()58     unsigned numR1Reductions() const { return r1Reductions; }
59 
60     /// \brief Records a reduction via the R2 rule. Should be called from the
61     ///        solver only.
recordR2()62     void recordR2() { ++r2Reductions; }
63 
64     /// \brief Returns the number of R2 reductions applied to solve the problem.
numR2Reductions()65     unsigned numR2Reductions() const { return r2Reductions; }
66 
67     /// \brief Records a reduction via the RN rule. Should be called from the
68     ///        solver only.
recordRN()69     void recordRN() { ++ rNReductions; }
70 
71     /// \brief Returns the number of RN reductions applied to solve the problem.
numRNReductions()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.
setSelection(Graph::NodeItr nItr,unsigned selection)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;
getSelection(Graph::ConstNodeItr 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