1 //===--------------------- SchedulerStatistics.cpp --------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// \file 9 /// 10 /// This file implements the SchedulerStatistics interface. 11 /// 12 //===----------------------------------------------------------------------===// 13 14 #include "Views/SchedulerStatistics.h" 15 #include "llvm/Support/Format.h" 16 #include "llvm/Support/FormattedStream.h" 17 18 namespace llvm { 19 namespace mca { 20 21 SchedulerStatistics::SchedulerStatistics(const llvm::MCSubtargetInfo &STI) 22 : SM(STI.getSchedModel()), LQResourceID(0), SQResourceID(0), NumIssued(0), 23 NumCycles(0), MostRecentLoadDispatched(~0U), 24 MostRecentStoreDispatched(~0U), 25 Usage(STI.getSchedModel().NumProcResourceKinds, {0, 0, 0}) { 26 if (SM.hasExtraProcessorInfo()) { 27 const MCExtraProcessorInfo &EPI = SM.getExtraProcessorInfo(); 28 LQResourceID = EPI.LoadQueueID; 29 SQResourceID = EPI.StoreQueueID; 30 } 31 } 32 33 // FIXME: This implementation works under the assumption that load/store queue 34 // entries are reserved at 'instruction dispatched' stage, and released at 35 // 'instruction executed' stage. This currently matches the behavior of LSUnit. 36 // 37 // The current design minimizes the number of events generated by the 38 // Dispatch/Execute stages, at the cost of doing extra bookkeeping in method 39 // `onEvent`. However, it introduces a subtle dependency between this view and 40 // how the LSUnit works. 41 // 42 // In future we should add a new "memory queue" event type, so that we stop 43 // making assumptions on how LSUnit internally works (See PR39828). 44 void SchedulerStatistics::onEvent(const HWInstructionEvent &Event) { 45 if (Event.Type == HWInstructionEvent::Issued) { 46 const Instruction &Inst = *Event.IR.getInstruction(); 47 NumIssued += Inst.getDesc().NumMicroOps; 48 } else if (Event.Type == HWInstructionEvent::Dispatched) { 49 const Instruction &Inst = *Event.IR.getInstruction(); 50 const unsigned Index = Event.IR.getSourceIndex(); 51 if (LQResourceID && Inst.getDesc().MayLoad && 52 MostRecentLoadDispatched != Index) { 53 Usage[LQResourceID].SlotsInUse++; 54 MostRecentLoadDispatched = Index; 55 } 56 if (SQResourceID && Inst.getDesc().MayStore && 57 MostRecentStoreDispatched != Index) { 58 Usage[SQResourceID].SlotsInUse++; 59 MostRecentStoreDispatched = Index; 60 } 61 } else if (Event.Type == HWInstructionEvent::Executed) { 62 const Instruction &Inst = *Event.IR.getInstruction(); 63 if (LQResourceID && Inst.getDesc().MayLoad) { 64 assert(Usage[LQResourceID].SlotsInUse); 65 Usage[LQResourceID].SlotsInUse--; 66 } 67 if (SQResourceID && Inst.getDesc().MayStore) { 68 assert(Usage[SQResourceID].SlotsInUse); 69 Usage[SQResourceID].SlotsInUse--; 70 } 71 } 72 } 73 74 void SchedulerStatistics::onReservedBuffers(const InstRef & /* unused */, 75 ArrayRef<unsigned> Buffers) { 76 for (const unsigned Buffer : Buffers) { 77 if (Buffer == LQResourceID || Buffer == SQResourceID) 78 continue; 79 Usage[Buffer].SlotsInUse++; 80 } 81 } 82 83 void SchedulerStatistics::onReleasedBuffers(const InstRef & /* unused */, 84 ArrayRef<unsigned> Buffers) { 85 for (const unsigned Buffer : Buffers) { 86 if (Buffer == LQResourceID || Buffer == SQResourceID) 87 continue; 88 Usage[Buffer].SlotsInUse--; 89 } 90 } 91 92 void SchedulerStatistics::updateHistograms() { 93 for (BufferUsage &BU : Usage) { 94 BU.CumulativeNumUsedSlots += BU.SlotsInUse; 95 BU.MaxUsedSlots = std::max(BU.MaxUsedSlots, BU.SlotsInUse); 96 } 97 98 IssueWidthPerCycle[NumIssued]++; 99 NumIssued = 0; 100 } 101 102 void SchedulerStatistics::printSchedulerStats(raw_ostream &OS) const { 103 OS << "\n\nSchedulers - " 104 << "number of cycles where we saw N micro opcodes issued:\n"; 105 OS << "[# issued], [# cycles]\n"; 106 107 bool HasColors = OS.has_colors(); 108 const auto It = 109 std::max_element(IssueWidthPerCycle.begin(), IssueWidthPerCycle.end()); 110 for (const std::pair<const unsigned, unsigned> &Entry : IssueWidthPerCycle) { 111 unsigned NumIssued = Entry.first; 112 if (NumIssued == It->first && HasColors) 113 OS.changeColor(raw_ostream::SAVEDCOLOR, true, false); 114 115 unsigned IPC = Entry.second; 116 OS << " " << NumIssued << ", " << IPC << " (" 117 << format("%.1f", ((double)IPC / NumCycles) * 100) << "%)\n"; 118 if (HasColors) 119 OS.resetColor(); 120 } 121 } 122 123 void SchedulerStatistics::printSchedulerUsage(raw_ostream &OS) const { 124 assert(NumCycles && "Unexpected number of cycles!"); 125 126 OS << "\nScheduler's queue usage:\n"; 127 if (all_of(Usage, [](const BufferUsage &BU) { return !BU.MaxUsedSlots; })) { 128 OS << "No scheduler resources used.\n"; 129 return; 130 } 131 132 OS << "[1] Resource name.\n" 133 << "[2] Average number of used buffer entries.\n" 134 << "[3] Maximum number of used buffer entries.\n" 135 << "[4] Total number of buffer entries.\n\n" 136 << " [1] [2] [3] [4]\n"; 137 138 formatted_raw_ostream FOS(OS); 139 bool HasColors = FOS.has_colors(); 140 for (unsigned I = 0, E = SM.getNumProcResourceKinds(); I < E; ++I) { 141 const MCProcResourceDesc &ProcResource = *SM.getProcResource(I); 142 if (ProcResource.BufferSize <= 0) 143 continue; 144 145 const BufferUsage &BU = Usage[I]; 146 double AvgUsage = (double)BU.CumulativeNumUsedSlots / NumCycles; 147 double AlmostFullThreshold = (double)(ProcResource.BufferSize * 4) / 5; 148 unsigned NormalizedAvg = floor((AvgUsage * 10) + 0.5) / 10; 149 unsigned NormalizedThreshold = floor((AlmostFullThreshold * 10) + 0.5) / 10; 150 151 FOS << ProcResource.Name; 152 FOS.PadToColumn(17); 153 if (HasColors && NormalizedAvg >= NormalizedThreshold) 154 FOS.changeColor(raw_ostream::YELLOW, true, false); 155 FOS << NormalizedAvg; 156 if (HasColors) 157 FOS.resetColor(); 158 FOS.PadToColumn(28); 159 if (HasColors && 160 BU.MaxUsedSlots == static_cast<unsigned>(ProcResource.BufferSize)) 161 FOS.changeColor(raw_ostream::RED, true, false); 162 FOS << BU.MaxUsedSlots; 163 if (HasColors) 164 FOS.resetColor(); 165 FOS.PadToColumn(39); 166 FOS << ProcResource.BufferSize << '\n'; 167 } 168 169 FOS.flush(); 170 } 171 172 void SchedulerStatistics::printView(raw_ostream &OS) const { 173 printSchedulerStats(OS); 174 printSchedulerUsage(OS); 175 } 176 177 } // namespace mca 178 } // namespace llvm 179