LatencyPriorityQueue.h revision 327952
1143611Sphilip//===---- LatencyPriorityQueue.h - A latency-oriented priority queue ------===// 2143611Sphilip// 3143611Sphilip// The LLVM Compiler Infrastructure 4143611Sphilip// 5143611Sphilip// This file is distributed under the University of Illinois Open Source 6143611Sphilip// License. See LICENSE.TXT for details. 7143611Sphilip// 8143611Sphilip//===----------------------------------------------------------------------===// 9143611Sphilip// 10143611Sphilip// This file declares the LatencyPriorityQueue class, which is a 11143611Sphilip// SchedulingPriorityQueue that schedules using latency information to 12143611Sphilip// reduce the length of the critical path through the basic block. 13143611Sphilip// 14143611Sphilip//===----------------------------------------------------------------------===// 15143611Sphilip 16143611Sphilip#ifndef LLVM_CODEGEN_LATENCYPRIORITYQUEUE_H 17143611Sphilip#define LLVM_CODEGEN_LATENCYPRIORITYQUEUE_H 18143611Sphilip 19143611Sphilip#include "llvm/CodeGen/ScheduleDAG.h" 20143611Sphilip 21143611Sphilipnamespace llvm { 22143611Sphilip class LatencyPriorityQueue; 23143611Sphilip 24143611Sphilip /// Sorting functions for the Available queue. 25143611Sphilip struct latency_sort { 26143611Sphilip LatencyPriorityQueue *PQ; 27143611Sphilip explicit latency_sort(LatencyPriorityQueue *pq) : PQ(pq) {} 28143611Sphilip 29216294Ssyrinx bool operator()(const SUnit* left, const SUnit* right) const; 30143611Sphilip }; 31143611Sphilip 32143611Sphilip class LatencyPriorityQueue : public SchedulingPriorityQueue { 33143611Sphilip // SUnits - The SUnits for the current graph. 34143611Sphilip std::vector<SUnit> *SUnits; 35143611Sphilip 36143611Sphilip /// NumNodesSolelyBlocking - This vector contains, for every node in the 37143626Sphilip /// Queue, the number of nodes that the node is the sole unscheduled 38143611Sphilip /// predecessor for. This is used as a tie-breaker heuristic for better 39143611Sphilip /// mobility. 40143611Sphilip std::vector<unsigned> NumNodesSolelyBlocking; 41143611Sphilip 42143611Sphilip /// Queue - The queue. 43143611Sphilip std::vector<SUnit*> Queue; 44143611Sphilip latency_sort Picker; 45143611Sphilip 46143611Sphilip public: 47143611Sphilip LatencyPriorityQueue() : Picker(this) { 48143611Sphilip } 49143611Sphilip 50143611Sphilip bool isBottomUp() const override { return false; } 51146531Sphilip 52143611Sphilip void initNodes(std::vector<SUnit> &sunits) override { 53143611Sphilip SUnits = &sunits; 54143611Sphilip NumNodesSolelyBlocking.resize(SUnits->size(), 0); 55143611Sphilip } 56143611Sphilip 57143611Sphilip void addNode(const SUnit *SU) override { 58143611Sphilip NumNodesSolelyBlocking.resize(SUnits->size(), 0); 59143611Sphilip } 60143611Sphilip 61143611Sphilip void updateNode(const SUnit *SU) override { 62143611Sphilip } 63143611Sphilip 64171173Smlaier void releaseState() override { 65143611Sphilip SUnits = nullptr; 66143611Sphilip } 67143611Sphilip 68143611Sphilip unsigned getLatency(unsigned NodeNum) const { 69143611Sphilip assert(NodeNum < (*SUnits).size()); 70143611Sphilip return (*SUnits)[NodeNum].getHeight(); 71143611Sphilip } 72143611Sphilip 73143611Sphilip unsigned getNumSolelyBlockNodes(unsigned NodeNum) const { 74143611Sphilip assert(NodeNum < NumNodesSolelyBlocking.size()); 75143611Sphilip return NumNodesSolelyBlocking[NodeNum]; 76143611Sphilip } 77143611Sphilip 78143611Sphilip bool empty() const override { return Queue.empty(); } 79143611Sphilip 80143611Sphilip void push(SUnit *U) override; 81143611Sphilip 82143611Sphilip SUnit *pop() override; 83143611Sphilip 84143611Sphilip void remove(SUnit *SU) override; 85143611Sphilip 86143611Sphilip // scheduledNode - As nodes are scheduled, we look to see if there are any 87143611Sphilip // successor nodes that have a single unscheduled predecessor. If so, that 88143611Sphilip // single predecessor has a higher priority, since scheduling it will make 89205607Ssyrinx // the node available. 90205607Ssyrinx void scheduledNode(SUnit *Node) override; 91205607Ssyrinx 92205607Ssyrinxprivate: 93205607Ssyrinx void AdjustPriorityOfUnscheduledPreds(SUnit *SU); 94205607Ssyrinx SUnit *getSingleUnscheduledPred(SUnit *SU); 95205607Ssyrinx }; 96205607Ssyrinx} 97205607Ssyrinx 98205607Ssyrinx#endif 99205607Ssyrinx