1//===- ScheduleDAGILP.h - ILP metric for ScheduleDAGInstrs ------*- 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// Definition of an ILP metric for machine level instruction scheduling.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CODEGEN_SCHEDULEDAGILP_H
15#define LLVM_CODEGEN_SCHEDULEDAGILP_H
16
17#include "llvm/Support/DataTypes.h"
18#include <vector>
19
20namespace llvm {
21
22class raw_ostream;
23class ScheduleDAGInstrs;
24class SUnit;
25
26/// \brief Represent the ILP of the subDAG rooted at a DAG node.
27struct ILPValue {
28  unsigned InstrCount;
29  unsigned Cycles;
30
31  ILPValue(): InstrCount(0), Cycles(0) {}
32
33  ILPValue(unsigned count, unsigned cycles):
34    InstrCount(count), Cycles(cycles) {}
35
36  bool isValid() const { return Cycles > 0; }
37
38  // Order by the ILP metric's value.
39  bool operator<(ILPValue RHS) const {
40    return (uint64_t)InstrCount * RHS.Cycles
41      < (uint64_t)Cycles * RHS.InstrCount;
42  }
43  bool operator>(ILPValue RHS) const {
44    return RHS < *this;
45  }
46  bool operator<=(ILPValue RHS) const {
47    return (uint64_t)InstrCount * RHS.Cycles
48      <= (uint64_t)Cycles * RHS.InstrCount;
49  }
50  bool operator>=(ILPValue RHS) const {
51    return RHS <= *this;
52  }
53
54#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
55  void print(raw_ostream &OS) const;
56
57  void dump() const;
58#endif
59};
60
61/// \brief Compute the values of each DAG node for an ILP metric.
62///
63/// This metric assumes that the DAG is a forest of trees with roots at the
64/// bottom of the schedule.
65class ScheduleDAGILP {
66  bool IsBottomUp;
67  std::vector<ILPValue> ILPValues;
68
69public:
70  ScheduleDAGILP(bool IsBU): IsBottomUp(IsBU) {}
71
72  /// \brief Initialize the result data with the size of the DAG.
73  void resize(unsigned NumSUnits);
74
75  /// \brief Compute the ILP metric for the subDAG at this root.
76  void computeILP(const SUnit *Root);
77
78  /// \brief Get the ILP value for a DAG node.
79  ILPValue getILP(const SUnit *SU);
80};
81
82raw_ostream &operator<<(raw_ostream &OS, const ILPValue &Val);
83
84} // namespace llvm
85
86#endif
87