LatencyPriorityQueue.h revision 198892
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#include "llvm/ADT/PriorityQueue.h" 21 22namespace llvm { 23 class LatencyPriorityQueue; 24 25 /// Sorting functions for the Available queue. 26 struct latency_sort : public std::binary_function<SUnit*, SUnit*, bool> { 27 LatencyPriorityQueue *PQ; 28 explicit latency_sort(LatencyPriorityQueue *pq) : PQ(pq) {} 29 30 bool operator()(const SUnit* left, const SUnit* right) const; 31 }; 32 33 class LatencyPriorityQueue : public SchedulingPriorityQueue { 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 /// IgnoreAntiDep - Ignore anti-dependencies 44 bool IgnoreAntiDep; 45 46 /// Queue - The queue. 47 PriorityQueue<SUnit*, std::vector<SUnit*>, latency_sort> Queue; 48 49public: 50 LatencyPriorityQueue() : IgnoreAntiDep(false), Queue(latency_sort(this)) { 51 } 52 53 void setIgnoreAntiDep(bool ignore) { 54 IgnoreAntiDep = ignore; 55 } 56 57 void initNodes(std::vector<SUnit> &sunits) { 58 SUnits = &sunits; 59 NumNodesSolelyBlocking.resize(SUnits->size(), 0); 60 } 61 62 void addNode(const SUnit *SU) { 63 NumNodesSolelyBlocking.resize(SUnits->size(), 0); 64 } 65 66 void updateNode(const SUnit *SU) { 67 } 68 69 void releaseState() { 70 SUnits = 0; 71 } 72 73 unsigned getLatency(unsigned NodeNum) const { 74 assert(NodeNum < (*SUnits).size()); 75 return (*SUnits)[NodeNum].getHeight(IgnoreAntiDep); 76 } 77 78 unsigned getNumSolelyBlockNodes(unsigned NodeNum) const { 79 assert(NodeNum < NumNodesSolelyBlocking.size()); 80 return NumNodesSolelyBlocking[NodeNum]; 81 } 82 83 unsigned size() const { return Queue.size(); } 84 85 bool empty() const { return Queue.empty(); } 86 87 virtual void push(SUnit *U) { 88 push_impl(U); 89 } 90 void push_impl(SUnit *U); 91 92 void push_all(const std::vector<SUnit *> &Nodes) { 93 for (unsigned i = 0, e = Nodes.size(); i != e; ++i) 94 push_impl(Nodes[i]); 95 } 96 97 SUnit *pop() { 98 if (empty()) return NULL; 99 SUnit *V = Queue.top(); 100 Queue.pop(); 101 return V; 102 } 103 104 void remove(SUnit *SU) { 105 assert(!Queue.empty() && "Not in queue!"); 106 Queue.erase_one(SU); 107 } 108 109 // ScheduledNode - As nodes are scheduled, we look to see if there are any 110 // successor nodes that have a single unscheduled predecessor. If so, that 111 // single predecessor has a higher priority, since scheduling it will make 112 // the node available. 113 void ScheduledNode(SUnit *Node); 114 115private: 116 void AdjustPriorityOfUnscheduledPreds(SUnit *SU); 117 SUnit *getSingleUnscheduledPred(SUnit *SU); 118 }; 119} 120 121#endif 122