1 //===----- ResourcePriorityQueue.h - A DFA-oriented priority queue -------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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
15 //===----------------------------------------------------------------------===//
17 #ifndef LLVM_CODEGEN_RESOURCEPRIORITYQUEUE_H
18 #define LLVM_CODEGEN_RESOURCEPRIORITYQUEUE_H
20 #include "llvm/CodeGen/DFAPacketizer.h"
21 #include "llvm/CodeGen/ScheduleDAG.h"
22 #include "llvm/CodeGen/SelectionDAGISel.h"
23 #include "llvm/MC/MCInstrItineraries.h"
24 #include "llvm/Target/TargetInstrInfo.h"
25 #include "llvm/Target/TargetRegisterInfo.h"
28 class ResourcePriorityQueue;
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) {}
35 bool operator()(const SUnit* left, const SUnit* right) const;
38 class ResourcePriorityQueue : public SchedulingPriorityQueue {
39 /// SUnits - The SUnits for the current graph.
40 std::vector<SUnit> *SUnits;
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
46 std::vector<unsigned> NumNodesSolelyBlocking;
48 /// Queue - The queue.
49 std::vector<SUnit*> Queue;
51 /// RegPressure - Tracking current reg pressure per register class.
53 std::vector<unsigned> RegPressure;
55 /// RegLimit - Tracking the number of allocatable registers per register
57 std::vector<unsigned> RegLimit;
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 std::unique_ptr<DFAPacketizer> ResourcesModel;
69 /// Resource model - packet/bundle model. Purely
70 /// internal at the time.
71 std::vector<SUnit*> Packet;
73 /// Heuristics for estimating register pressure.
74 unsigned ParallelLiveRanges;
75 signed HorizontalVerticalBalance;
78 ResourcePriorityQueue(SelectionDAGISel *IS);
80 bool isBottomUp() const override { return false; }
82 void initNodes(std::vector<SUnit> &sunits) override;
84 void addNode(const SUnit *SU) override {
85 NumNodesSolelyBlocking.resize(SUnits->size(), 0);
88 void updateNode(const SUnit *SU) override {}
90 void releaseState() override {
94 unsigned getLatency(unsigned NodeNum) const {
95 assert(NodeNum < (*SUnits).size());
96 return (*SUnits)[NodeNum].getHeight();
99 unsigned getNumSolelyBlockNodes(unsigned NodeNum) const {
100 assert(NodeNum < NumNodesSolelyBlocking.size());
101 return NumNodesSolelyBlocking[NodeNum];
104 /// Single cost function reflecting benefit of scheduling SU
105 /// in the current cycle.
106 signed SUSchedulingCost (SUnit *SU);
108 /// InitNumRegDefsLeft - Determine the # of regs defined by this node.
110 void initNumRegDefsLeft(SUnit *SU);
111 void updateNumRegDefsLeft(SUnit *SU);
112 signed regPressureDelta(SUnit *SU, bool RawPressure = false);
113 signed rawRegPressureDelta (SUnit *SU, unsigned RCId);
115 bool empty() const override { return Queue.empty(); }
117 void push(SUnit *U) override;
119 SUnit *pop() override;
121 void remove(SUnit *SU) override;
123 /// scheduledNode - Main resource tracking point.
124 void scheduledNode(SUnit *Node) override;
125 bool isResourceAvailable(SUnit *SU);
126 void reserveResources(SUnit *SU);
129 void adjustPriorityOfUnscheduledPreds(SUnit *SU);
130 SUnit *getSingleUnscheduledPred(SUnit *SU);
131 unsigned numberRCValPredInSU (SUnit *SU, unsigned RCId);
132 unsigned numberRCValSuccInSU (SUnit *SU, unsigned RCId);