LatencyPriorityQueue.h revision 208599
1129198Scognet//===---- LatencyPriorityQueue.h - A latency-oriented priority queue ------===// 2129198Scognet// 3139735Simp// The LLVM Compiler Infrastructure 4129198Scognet// 5129198Scognet// This file is distributed under the University of Illinois Open Source 6129198Scognet// License. See LICENSE.TXT for details. 7129198Scognet// 8129198Scognet//===----------------------------------------------------------------------===// 9129198Scognet// 10129198Scognet// This file declares the LatencyPriorityQueue class, which is a 11129198Scognet// SchedulingPriorityQueue that schedules using latency information to 12129198Scognet// reduce the length of the critical path through the basic block. 13129198Scognet// 14129198Scognet//===----------------------------------------------------------------------===// 15129198Scognet 16129198Scognet#ifndef LATENCY_PRIORITY_QUEUE_H 17129198Scognet#define LATENCY_PRIORITY_QUEUE_H 18129198Scognet 19129198Scognet#include "llvm/CodeGen/ScheduleDAG.h" 20129198Scognet 21129198Scognetnamespace llvm { 22129198Scognet class LatencyPriorityQueue; 23129198Scognet 24129198Scognet /// Sorting functions for the Available queue. 25129198Scognet struct latency_sort : public std::binary_function<SUnit*, SUnit*, bool> { 26129198Scognet LatencyPriorityQueue *PQ; 27129198Scognet explicit latency_sort(LatencyPriorityQueue *pq) : PQ(pq) {} 28129198Scognet 29129198Scognet bool operator()(const SUnit* left, const SUnit* right) const; 30129198Scognet }; 31129198Scognet 32129198Scognet class LatencyPriorityQueue : public SchedulingPriorityQueue { 33129198Scognet // SUnits - The SUnits for the current graph. 34129198Scognet std::vector<SUnit> *SUnits; 35129198Scognet 36129198Scognet /// NumNodesSolelyBlocking - This vector contains, for every node in the 37129198Scognet /// Queue, the number of nodes that the node is the sole unscheduled 38129198Scognet /// predecessor for. This is used as a tie-breaker heuristic for better 39129198Scognet /// mobility. 40129198Scognet std::vector<unsigned> NumNodesSolelyBlocking; 41129198Scognet 42129198Scognet /// Queue - The queue. 43129198Scognet std::vector<SUnit*> Queue; 44129198Scognet latency_sort Picker; 45129198Scognet 46129198Scognet public: 47129198Scognet LatencyPriorityQueue() : Picker(this) { 48129198Scognet } 49129198Scognet 50129198Scognet void initNodes(std::vector<SUnit> &sunits) { 51129198Scognet SUnits = &sunits; 52129198Scognet NumNodesSolelyBlocking.resize(SUnits->size(), 0); 53129198Scognet } 54129198Scognet 55129198Scognet void addNode(const SUnit *SU) { 56129198Scognet NumNodesSolelyBlocking.resize(SUnits->size(), 0); 57129198Scognet } 58129198Scognet 59129198Scognet void updateNode(const SUnit *SU) { 60129198Scognet } 61129198Scognet 62129198Scognet void releaseState() { 63129198Scognet SUnits = 0; 64129198Scognet } 65129198Scognet 66129198Scognet unsigned getLatency(unsigned NodeNum) const { 67129198Scognet assert(NodeNum < (*SUnits).size()); 68129198Scognet return (*SUnits)[NodeNum].getHeight(); 69129198Scognet } 70129198Scognet 71129198Scognet unsigned getNumSolelyBlockNodes(unsigned NodeNum) const { 72 assert(NodeNum < NumNodesSolelyBlocking.size()); 73 return NumNodesSolelyBlocking[NodeNum]; 74 } 75 76 bool empty() const { return Queue.empty(); } 77 78 virtual void push(SUnit *U); 79 80 virtual SUnit *pop(); 81 82 virtual void remove(SUnit *SU); 83 84 // ScheduledNode - As nodes are scheduled, we look to see if there are any 85 // successor nodes that have a single unscheduled predecessor. If so, that 86 // single predecessor has a higher priority, since scheduling it will make 87 // the node available. 88 void ScheduledNode(SUnit *Node); 89 90private: 91 void AdjustPriorityOfUnscheduledPreds(SUnit *SU); 92 SUnit *getSingleUnscheduledPred(SUnit *SU); 93 }; 94} 95 96#endif 97