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 LATENCY_PRIORITY_QUEUE_H 17 #define LATENCY_PRIORITY_QUEUE_H 18 19 #include "llvm/CodeGen/ScheduleDAG.h" 20 21 namespace llvm { 22 class LatencyPriorityQueue; 23 24 /// Sorting functions for the Available queue. 25 struct latency_sort : public std::binary_function<SUnit*, SUnit*, bool> { 26 LatencyPriorityQueue *PQ; latency_sortlatency_sort27 explicit latency_sort(LatencyPriorityQueue *pq) : PQ(pq) {} 28 29 bool operator()(const SUnit* left, const SUnit* right) const; 30 }; 31 32 class LatencyPriorityQueue : public SchedulingPriorityQueue { 33 // SUnits - The SUnits for the current graph. 34 std::vector<SUnit> *SUnits; 35 36 /// NumNodesSolelyBlocking - This vector contains, for every node in the 37 /// Queue, the number of nodes that the node is the sole unscheduled 38 /// predecessor for. This is used as a tie-breaker heuristic for better 39 /// mobility. 40 std::vector<unsigned> NumNodesSolelyBlocking; 41 42 /// Queue - The queue. 43 std::vector<SUnit*> Queue; 44 latency_sort Picker; 45 46 public: LatencyPriorityQueue()47 LatencyPriorityQueue() : Picker(this) { 48 } 49 isBottomUp()50 bool isBottomUp() const { return false; } 51 initNodes(std::vector<SUnit> & sunits)52 void initNodes(std::vector<SUnit> &sunits) { 53 SUnits = &sunits; 54 NumNodesSolelyBlocking.resize(SUnits->size(), 0); 55 } 56 addNode(const SUnit * SU)57 void addNode(const SUnit *SU) { 58 NumNodesSolelyBlocking.resize(SUnits->size(), 0); 59 } 60 updateNode(const SUnit * SU)61 void updateNode(const SUnit *SU) { 62 } 63 releaseState()64 void releaseState() { 65 SUnits = 0; 66 } 67 getLatency(unsigned NodeNum)68 unsigned getLatency(unsigned NodeNum) const { 69 assert(NodeNum < (*SUnits).size()); 70 return (*SUnits)[NodeNum].getHeight(); 71 } 72 getNumSolelyBlockNodes(unsigned NodeNum)73 unsigned getNumSolelyBlockNodes(unsigned NodeNum) const { 74 assert(NodeNum < NumNodesSolelyBlocking.size()); 75 return NumNodesSolelyBlocking[NodeNum]; 76 } 77 empty()78 bool empty() const { return Queue.empty(); } 79 80 virtual void push(SUnit *U); 81 82 virtual SUnit *pop(); 83 84 virtual void remove(SUnit *SU); 85 86 virtual void dump(ScheduleDAG* DAG) const; 87 88 // ScheduledNode - As nodes are scheduled, we look to see if there are any 89 // successor nodes that have a single unscheduled predecessor. If so, that 90 // single predecessor has a higher priority, since scheduling it will make 91 // the node available. 92 void ScheduledNode(SUnit *Node); 93 94 private: 95 void AdjustPriorityOfUnscheduledPreds(SUnit *SU); 96 SUnit *getSingleUnscheduledPred(SUnit *SU); 97 }; 98 } 99 100 #endif 101