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1//===----- ResourcePriorityQueue.h - A DFA-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 implements the ResourcePriorityQueue class, which is a
11// SchedulingPriorityQueue that schedules using DFA state to
12// reduce the length of the critical path through the basic block
13// on VLIW platforms.
14//
15//===----------------------------------------------------------------------===//
16
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17#ifndef LLVM_CODEGEN_RESOURCEPRIORITYQUEUE_H
18#define LLVM_CODEGEN_RESOURCEPRIORITYQUEUE_H
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19
20#include "llvm/CodeGen/DFAPacketizer.h"
223e47cc 21#include "llvm/CodeGen/ScheduleDAG.h"
970d7e83 22#include "llvm/CodeGen/SelectionDAGISel.h"
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23#include "llvm/MC/MCInstrItineraries.h"
24#include "llvm/Target/TargetInstrInfo.h"
25#include "llvm/Target/TargetRegisterInfo.h"
26
27namespace llvm {
28 class ResourcePriorityQueue;
29
30 /// Sorting functions for the Available queue.
31 struct resource_sort : public std::binary_function<SUnit*, SUnit*, bool> {
32 ResourcePriorityQueue *PQ;
33 explicit resource_sort(ResourcePriorityQueue *pq) : PQ(pq) {}
34
35 bool operator()(const SUnit* left, const SUnit* right) const;
36 };
37
38 class ResourcePriorityQueue : public SchedulingPriorityQueue {
39 /// SUnits - The SUnits for the current graph.
40 std::vector<SUnit> *SUnits;
41
42 /// NumNodesSolelyBlocking - This vector contains, for every node in the
43 /// Queue, the number of nodes that the node is the sole unscheduled
44 /// predecessor for. This is used as a tie-breaker heuristic for better
45 /// mobility.
46 std::vector<unsigned> NumNodesSolelyBlocking;
47
48 /// Queue - The queue.
49 std::vector<SUnit*> Queue;
50
51 /// RegPressure - Tracking current reg pressure per register class.
52 ///
53 std::vector<unsigned> RegPressure;
54
55 /// RegLimit - Tracking the number of allocatable registers per register
56 /// class.
57 std::vector<unsigned> RegLimit;
58
59 resource_sort Picker;
60 const TargetRegisterInfo *TRI;
61 const TargetLowering *TLI;
62 const TargetInstrInfo *TII;
63 const InstrItineraryData* InstrItins;
64 /// ResourcesModel - Represents VLIW state.
65 /// Not limited to VLIW targets per say, but assumes
66 /// definition of DFA by a target.
67 DFAPacketizer *ResourcesModel;
68
69 /// Resource model - packet/bundle model. Purely
70 /// internal at the time.
71 std::vector<SUnit*> Packet;
72
73 /// Heuristics for estimating register pressure.
74 unsigned ParallelLiveRanges;
75 signed HorizontalVerticalBalance;
76
77 public:
78 ResourcePriorityQueue(SelectionDAGISel *IS);
79
80 ~ResourcePriorityQueue() {
81 delete ResourcesModel;
82 }
83
1a4d82fc 84 bool isBottomUp() const override { return false; }
223e47cc 85
1a4d82fc 86 void initNodes(std::vector<SUnit> &sunits) override;
223e47cc 87
1a4d82fc 88 void addNode(const SUnit *SU) override {
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89 NumNodesSolelyBlocking.resize(SUnits->size(), 0);
90 }
91
1a4d82fc 92 void updateNode(const SUnit *SU) override {}
223e47cc 93
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94 void releaseState() override {
95 SUnits = nullptr;
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96 }
97
98 unsigned getLatency(unsigned NodeNum) const {
99 assert(NodeNum < (*SUnits).size());
100 return (*SUnits)[NodeNum].getHeight();
101 }
102
103 unsigned getNumSolelyBlockNodes(unsigned NodeNum) const {
104 assert(NodeNum < NumNodesSolelyBlocking.size());
105 return NumNodesSolelyBlocking[NodeNum];
106 }
107
108 /// Single cost function reflecting benefit of scheduling SU
109 /// in the current cycle.
110 signed SUSchedulingCost (SUnit *SU);
111
112 /// InitNumRegDefsLeft - Determine the # of regs defined by this node.
113 ///
114 void initNumRegDefsLeft(SUnit *SU);
115 void updateNumRegDefsLeft(SUnit *SU);
116 signed regPressureDelta(SUnit *SU, bool RawPressure = false);
117 signed rawRegPressureDelta (SUnit *SU, unsigned RCId);
118
1a4d82fc 119 bool empty() const override { return Queue.empty(); }
223e47cc 120
1a4d82fc 121 void push(SUnit *U) override;
223e47cc 122
1a4d82fc 123 SUnit *pop() override;
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1a4d82fc 125 void remove(SUnit *SU) override;
223e47cc 126
1a4d82fc 127 void dump(ScheduleDAG* DAG) const override;
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128
129 /// scheduledNode - Main resource tracking point.
1a4d82fc 130 void scheduledNode(SUnit *Node) override;
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131 bool isResourceAvailable(SUnit *SU);
132 void reserveResources(SUnit *SU);
133
134private:
135 void adjustPriorityOfUnscheduledPreds(SUnit *SU);
136 SUnit *getSingleUnscheduledPred(SUnit *SU);
137 unsigned numberRCValPredInSU (SUnit *SU, unsigned RCId);
138 unsigned numberRCValSuccInSU (SUnit *SU, unsigned RCId);
139 };
140}
141
142#endif