tools/llvm-mca/Views/TimelineView.cpp

   1 //===--------------------- TimelineView.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 /// \brief
   9 ///
  10 /// This file implements the TimelineView interface.
  11 ///
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "Views/TimelineView.h"
  15
  16 namespace llvm {
  17 namespace mca {
  18
  19 TimelineView::TimelineView(const MCSubtargetInfo &sti, MCInstPrinter &Printer,
  20                            llvm::ArrayRef<llvm::MCInst> S, unsigned Iterations,
  21                            unsigned Cycles)
  22     : STI(sti), MCIP(Printer), Source(S), CurrentCycle(0),
  23       MaxCycle(Cycles == 0 ? 80 : Cycles), LastCycle(0), WaitTime(S.size()),
  24       UsedBuffer(S.size()) {
  25   unsigned NumInstructions = Source.size();
  26   assert(Iterations && "Invalid number of iterations specified!");
  27   NumInstructions *= Iterations;
  28   Timeline.resize(NumInstructions);
  29   TimelineViewEntry InvalidTVEntry = {-1, 0, 0, 0, 0};
  30   std::fill(Timeline.begin(), Timeline.end(), InvalidTVEntry);
  31
  32   WaitTimeEntry NullWTEntry = {0, 0, 0};
  33   std::fill(WaitTime.begin(), WaitTime.end(), NullWTEntry);
  34
  35   std::pair<unsigned, int> NullUsedBufferEntry = {/* Invalid resource ID*/ 0,
  36                                                   /* unknown buffer size */ -1};
  37   std::fill(UsedBuffer.begin(), UsedBuffer.end(), NullUsedBufferEntry);
  38 }
  39
  40 void TimelineView::onReservedBuffers(const InstRef &IR,
  41                                      ArrayRef<unsigned> Buffers) {
  42   if (IR.getSourceIndex() >= Source.size())
  43     return;
  44
  45   const MCSchedModel &SM = STI.getSchedModel();
  46   std::pair<unsigned, int> BufferInfo = {0, -1};
  47   for (const unsigned Buffer : Buffers) {
  48     const MCProcResourceDesc &MCDesc = *SM.getProcResource(Buffer);
  49     if (!BufferInfo.first || BufferInfo.second > MCDesc.BufferSize) {
  50       BufferInfo.first = Buffer;
  51       BufferInfo.second = MCDesc.BufferSize;
  52     }
  53   }
  54
  55   UsedBuffer[IR.getSourceIndex()] = BufferInfo;
  56 }
  57
  58 void TimelineView::onEvent(const HWInstructionEvent &Event) {
  59   const unsigned Index = Event.IR.getSourceIndex();
  60   if (Index >= Timeline.size())
  61     return;
  62
  63   switch (Event.Type) {
  64   case HWInstructionEvent::Retired: {
  65     TimelineViewEntry &TVEntry = Timeline[Index];
  66     if (CurrentCycle < MaxCycle)
  67       TVEntry.CycleRetired = CurrentCycle;
  68
  69     // Update the WaitTime entry which corresponds to this Index.
  70     assert(TVEntry.CycleDispatched >= 0 && "Invalid TVEntry found!");
  71     unsigned CycleDispatched = static_cast<unsigned>(TVEntry.CycleDispatched);
  72     WaitTimeEntry &WTEntry = WaitTime[Index % Source.size()];
  73     WTEntry.CyclesSpentInSchedulerQueue +=
  74         TVEntry.CycleIssued - CycleDispatched;
  75     assert(CycleDispatched <= TVEntry.CycleReady &&
  76            "Instruction cannot be ready if it hasn't been dispatched yet!");
  77     WTEntry.CyclesSpentInSQWhileReady +=
  78         TVEntry.CycleIssued - TVEntry.CycleReady;
  79     WTEntry.CyclesSpentAfterWBAndBeforeRetire +=
  80         (CurrentCycle - 1) - TVEntry.CycleExecuted;
  81     break;
  82   }
  83   case HWInstructionEvent::Ready:
  84     Timeline[Index].CycleReady = CurrentCycle;
  85     break;
  86   case HWInstructionEvent::Issued:
  87     Timeline[Index].CycleIssued = CurrentCycle;
  88     break;
  89   case HWInstructionEvent::Executed:
  90     Timeline[Index].CycleExecuted = CurrentCycle;
  91     break;
  92   case HWInstructionEvent::Dispatched:
  93     // There may be multiple dispatch events. Microcoded instructions that are
  94     // expanded into multiple uOps may require multiple dispatch cycles. Here,
  95     // we want to capture the first dispatch cycle.
  96     if (Timeline[Index].CycleDispatched == -1)
  97       Timeline[Index].CycleDispatched = static_cast<int>(CurrentCycle);
  98     break;
  99   default:
 100     return;
 101   }
 102   if (CurrentCycle < MaxCycle)
 103     LastCycle = std::max(LastCycle, CurrentCycle);
 104 }
 105
 106 static raw_ostream::Colors chooseColor(unsigned CumulativeCycles,
 107                                        unsigned Executions, int BufferSize) {
 108   if (CumulativeCycles && BufferSize < 0)
 109     return raw_ostream::MAGENTA;
 110   unsigned Size = static_cast<unsigned>(BufferSize);
 111   if (CumulativeCycles >= Size * Executions)
 112     return raw_ostream::RED;
 113   if ((CumulativeCycles * 2) >= Size * Executions)
 114     return raw_ostream::YELLOW;
 115   return raw_ostream::SAVEDCOLOR;
 116 }
 117
 118 static void tryChangeColor(raw_ostream &OS, unsigned Cycles,
 119                            unsigned Executions, int BufferSize) {
 120   if (!OS.has_colors())
 121     return;
 122
 123   raw_ostream::Colors Color = chooseColor(Cycles, Executions, BufferSize);
 124   if (Color == raw_ostream::SAVEDCOLOR) {
 125     OS.resetColor();
 126     return;
 127   }
 128   OS.changeColor(Color, /* bold */ true, /* BG */ false);
 129 }
 130
 131 void TimelineView::printWaitTimeEntry(formatted_raw_ostream &OS,
 132                                       const WaitTimeEntry &Entry,
 133                                       unsigned SourceIndex,
 134                                       unsigned Executions) const {
 135   OS << SourceIndex << '.';
 136   OS.PadToColumn(7);
 137
 138   double AverageTime1, AverageTime2, AverageTime3;
 139   AverageTime1 = (double)Entry.CyclesSpentInSchedulerQueue / Executions;
 140   AverageTime2 = (double)Entry.CyclesSpentInSQWhileReady / Executions;
 141   AverageTime3 = (double)Entry.CyclesSpentAfterWBAndBeforeRetire / Executions;
 142
 143   OS << Executions;
 144   OS.PadToColumn(13);
 145   int BufferSize = UsedBuffer[SourceIndex].second;
 146   tryChangeColor(OS, Entry.CyclesSpentInSchedulerQueue, Executions, BufferSize);
 147   OS << format("%.1f", floor((AverageTime1 * 10) + 0.5) / 10);
 148   OS.PadToColumn(20);
 149   tryChangeColor(OS, Entry.CyclesSpentInSQWhileReady, Executions, BufferSize);
 150   OS << format("%.1f", floor((AverageTime2 * 10) + 0.5) / 10);
 151   OS.PadToColumn(27);
 152   tryChangeColor(OS, Entry.CyclesSpentAfterWBAndBeforeRetire, Executions,
 153                  STI.getSchedModel().MicroOpBufferSize);
 154   OS << format("%.1f", floor((AverageTime3 * 10) + 0.5) / 10);
 155
 156   if (OS.has_colors())
 157     OS.resetColor();
 158   OS.PadToColumn(34);
 159 }
 160
 161 void TimelineView::printAverageWaitTimes(raw_ostream &OS) const {
 162   std::string Header =
 163       "\n\nAverage Wait times (based on the timeline view):\n"
 164       "[0]: Executions\n"
 165       "[1]: Average time spent waiting in a scheduler's queue\n"
 166       "[2]: Average time spent waiting in a scheduler's queue while ready\n"
 167       "[3]: Average time elapsed from WB until retire stage\n\n"
 168       "      [0]    [1]    [2]    [3]\n";
 169   OS << Header;
 170
 171   // Use a different string stream for printing instructions.
 172   std::string Instruction;
 173   raw_string_ostream InstrStream(Instruction);
 174
 175   formatted_raw_ostream FOS(OS);
 176   unsigned Executions = Timeline.size() / Source.size();
 177   unsigned IID = 0;
 178   for (const MCInst &Inst : Source) {
 179     printWaitTimeEntry(FOS, WaitTime[IID], IID, Executions);
 180     // Append the instruction info at the end of the line.
 181     MCIP.printInst(&Inst, InstrStream, "", STI);
 182     InstrStream.flush();
 183
 184     // Consume any tabs or spaces at the beginning of the string.
 185     StringRef Str(Instruction);
 186     Str = Str.ltrim();
 187     FOS << "   " << Str << '\n';
 188     FOS.flush();
 189     Instruction = "";
 190
 191     ++IID;
 192   }
 193 }
 194
 195 void TimelineView::printTimelineViewEntry(formatted_raw_ostream &OS,
 196                                           const TimelineViewEntry &Entry,
 197                                           unsigned Iteration,
 198                                           unsigned SourceIndex) const {
 199   if (Iteration == 0 && SourceIndex == 0)
 200     OS << '\n';
 201   OS << '[' << Iteration << ',' << SourceIndex << ']';
 202   OS.PadToColumn(10);
 203   assert(Entry.CycleDispatched >= 0 && "Invalid TimelineViewEntry!");
 204   unsigned CycleDispatched = static_cast<unsigned>(Entry.CycleDispatched);
 205   for (unsigned I = 0, E = CycleDispatched; I < E; ++I)
 206     OS << ((I % 5 == 0) ? '.' : ' ');
 207   OS << TimelineView::DisplayChar::Dispatched;
 208   if (CycleDispatched != Entry.CycleExecuted) {
 209     // Zero latency instructions have the same value for CycleDispatched,
 210     // CycleIssued and CycleExecuted.
 211     for (unsigned I = CycleDispatched + 1, E = Entry.CycleIssued; I < E; ++I)
 212       OS << TimelineView::DisplayChar::Waiting;
 213     if (Entry.CycleIssued == Entry.CycleExecuted)
 214       OS << TimelineView::DisplayChar::DisplayChar::Executed;
 215     else {
 216       if (CycleDispatched != Entry.CycleIssued)
 217         OS << TimelineView::DisplayChar::Executing;
 218       for (unsigned I = Entry.CycleIssued + 1, E = Entry.CycleExecuted; I < E;
 219            ++I)
 220         OS << TimelineView::DisplayChar::Executing;
 221       OS << TimelineView::DisplayChar::Executed;
 222     }
 223   }
 224
 225   for (unsigned I = Entry.CycleExecuted + 1, E = Entry.CycleRetired; I < E; ++I)
 226     OS << TimelineView::DisplayChar::RetireLag;
 227   OS << TimelineView::DisplayChar::Retired;
 228
 229   // Skip other columns.
 230   for (unsigned I = Entry.CycleRetired + 1, E = LastCycle; I <= E; ++I)
 231     OS << ((I % 5 == 0 || I == LastCycle) ? '.' : ' ');
 232 }
 233
 234 static void printTimelineHeader(formatted_raw_ostream &OS, unsigned Cycles) {
 235   OS << "\n\nTimeline view:\n";
 236   if (Cycles >= 10) {
 237     OS.PadToColumn(10);
 238     for (unsigned I = 0; I <= Cycles; ++I) {
 239       if (((I / 10) & 1) == 0)
 240         OS << ' ';
 241       else
 242         OS << I % 10;
 243     }
 244     OS << '\n';
 245   }
 246
 247   OS << "Index";
 248   OS.PadToColumn(10);
 249   for (unsigned I = 0; I <= Cycles; ++I) {
 250     if (((I / 10) & 1) == 0)
 251       OS << I % 10;
 252     else
 253       OS << ' ';
 254   }
 255   OS << '\n';
 256 }
 257
 258 void TimelineView::printTimeline(raw_ostream &OS) const {
 259   formatted_raw_ostream FOS(OS);
 260   printTimelineHeader(FOS, LastCycle);
 261   FOS.flush();
 262
 263   // Use a different string stream for the instruction.
 264   std::string Instruction;
 265   raw_string_ostream InstrStream(Instruction);
 266
 267   unsigned IID = 0;
 268   const unsigned Iterations = Timeline.size() / Source.size();
 269   for (unsigned Iteration = 0; Iteration < Iterations; ++Iteration) {
 270     for (const MCInst &Inst : Source) {
 271       const TimelineViewEntry &Entry = Timeline[IID];
 272       if (Entry.CycleRetired == 0)
 273         return;
 274
 275       unsigned SourceIndex = IID % Source.size();
 276       printTimelineViewEntry(FOS, Entry, Iteration, SourceIndex);
 277       // Append the instruction info at the end of the line.
 278       MCIP.printInst(&Inst, InstrStream, "", STI);
 279       InstrStream.flush();
 280
 281       // Consume any tabs or spaces at the beginning of the string.
 282       StringRef Str(Instruction);
 283       Str = Str.ltrim();
 284       FOS << "   " << Str << '\n';
 285       FOS.flush();
 286       Instruction = "";
 287
 288       ++IID;
 289     }
 290   }
 291 }
 292 } // namespace mca
 293 } // namespace llvm