LLVM  8.0.0svn
LatencyPriorityQueue.h
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1 //===---- LatencyPriorityQueue.h - A latency-oriented priority queue ------===//
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 // This file declares the LatencyPriorityQueue class, which is a
11 // SchedulingPriorityQueue that schedules using latency information to
12 // reduce the length of the critical path through the basic block.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CODEGEN_LATENCYPRIORITYQUEUE_H
17 #define LLVM_CODEGEN_LATENCYPRIORITYQUEUE_H
18 
20 #include "llvm/Config/llvm-config.h"
21 
22 namespace llvm {
23  class LatencyPriorityQueue;
24 
25  /// Sorting functions for the Available queue.
26  struct latency_sort {
28  explicit latency_sort(LatencyPriorityQueue *pq) : PQ(pq) {}
29 
30  bool operator()(const SUnit* LHS, const SUnit* RHS) const;
31  };
32 
34  // SUnits - The SUnits for the current graph.
35  std::vector<SUnit> *SUnits;
36 
37  /// NumNodesSolelyBlocking - This vector contains, for every node in the
38  /// Queue, the number of nodes that the node is the sole unscheduled
39  /// predecessor for. This is used as a tie-breaker heuristic for better
40  /// mobility.
41  std::vector<unsigned> NumNodesSolelyBlocking;
42 
43  /// Queue - The queue.
44  std::vector<SUnit*> Queue;
45  latency_sort Picker;
46 
47  public:
48  LatencyPriorityQueue() : Picker(this) {
49  }
50 
51  bool isBottomUp() const override { return false; }
52 
53  void initNodes(std::vector<SUnit> &sunits) override {
54  SUnits = &sunits;
55  NumNodesSolelyBlocking.resize(SUnits->size(), 0);
56  }
57 
58  void addNode(const SUnit *SU) override {
59  NumNodesSolelyBlocking.resize(SUnits->size(), 0);
60  }
61 
62  void updateNode(const SUnit *SU) override {
63  }
64 
65  void releaseState() override {
66  SUnits = nullptr;
67  }
68 
69  unsigned getLatency(unsigned NodeNum) const {
70  assert(NodeNum < (*SUnits).size());
71  return (*SUnits)[NodeNum].getHeight();
72  }
73 
74  unsigned getNumSolelyBlockNodes(unsigned NodeNum) const {
75  assert(NodeNum < NumNodesSolelyBlocking.size());
76  return NumNodesSolelyBlocking[NodeNum];
77  }
78 
79  bool empty() const override { return Queue.empty(); }
80 
81  void push(SUnit *U) override;
82 
83  SUnit *pop() override;
84 
85  void remove(SUnit *SU) override;
86 
87 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
88  LLVM_DUMP_METHOD void dump(ScheduleDAG *DAG) const override;
89 #endif
90 
91  // scheduledNode - As nodes are scheduled, we look to see if there are any
92  // successor nodes that have a single unscheduled predecessor. If so, that
93  // single predecessor has a higher priority, since scheduling it will make
94  // the node available.
95  void scheduledNode(SUnit *SU) override;
96 
97 private:
98  void AdjustPriorityOfUnscheduledPreds(SUnit *SU);
99  SUnit *getSingleUnscheduledPred(SUnit *SU);
100  };
101 }
102 
103 #endif
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
This interface is used to plug different priorities computation algorithms into the list scheduler...
Definition: ScheduleDAG.h:500
#define LLVM_DUMP_METHOD
Definition: Compiler.h:74
bool operator()(const SUnit *LHS, const SUnit *RHS) const
void dump(const SparseBitVector< ElementSize > &LHS, raw_ostream &out)
unsigned getLatency(unsigned NodeNum) const
latency_sort(LatencyPriorityQueue *pq)
Sorting functions for the Available queue.
LatencyPriorityQueue * PQ
unsigned getNumSolelyBlockNodes(unsigned NodeNum) const
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
void addNode(const SUnit *SU) override
bool empty() const override
void initNodes(std::vector< SUnit > &sunits) override
bool isBottomUp() const override
Scheduling unit. This is a node in the scheduling DAG.
Definition: ScheduleDAG.h:246
void updateNode(const SUnit *SU) override