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 #include <numeric>
16 
17 namespace llvm {
18 namespace mca {
19 
20 TimelineView::TimelineView(const MCSubtargetInfo &sti, MCInstPrinter &Printer,
21                            llvm::ArrayRef<llvm::MCInst> S, unsigned Iterations,
22                            unsigned Cycles)
23     : InstructionView(sti, Printer, S), CurrentCycle(0),
24       MaxCycle(Cycles == 0 ? 80 : Cycles), LastCycle(0), WaitTime(S.size()),
25       UsedBuffer(S.size()) {
26   unsigned NumInstructions = getSource().size();
27   assert(Iterations && "Invalid number of iterations specified!");
28   NumInstructions *= Iterations;
29   Timeline.resize(NumInstructions);
30   TimelineViewEntry InvalidTVEntry = {-1, 0, 0, 0, 0};
31   std::fill(Timeline.begin(), Timeline.end(), InvalidTVEntry);
32 
33   WaitTimeEntry NullWTEntry = {0, 0, 0};
34   std::fill(WaitTime.begin(), WaitTime.end(), NullWTEntry);
35 
36   std::pair<unsigned, int> NullUsedBufferEntry = {/* Invalid resource ID*/ 0,
37                                                   /* unknown buffer size */ -1};
38   std::fill(UsedBuffer.begin(), UsedBuffer.end(), NullUsedBufferEntry);
39 }
40 
41 void TimelineView::onReservedBuffers(const InstRef &IR,
42                                      ArrayRef<unsigned> Buffers) {
43   if (IR.getSourceIndex() >= getSource().size())
44     return;
45 
46   const MCSchedModel &SM = getSubTargetInfo().getSchedModel();
47   std::pair<unsigned, int> BufferInfo = {0, -1};
48   for (const unsigned Buffer : Buffers) {
49     const MCProcResourceDesc &MCDesc = *SM.getProcResource(Buffer);
50     if (!BufferInfo.first || BufferInfo.second > MCDesc.BufferSize) {
51       BufferInfo.first = Buffer;
52       BufferInfo.second = MCDesc.BufferSize;
53     }
54   }
55 
56   UsedBuffer[IR.getSourceIndex()] = BufferInfo;
57 }
58 
59 void TimelineView::onEvent(const HWInstructionEvent &Event) {
60   const unsigned Index = Event.IR.getSourceIndex();
61   if (Index >= Timeline.size())
62     return;
63 
64   switch (Event.Type) {
65   case HWInstructionEvent::Retired: {
66     TimelineViewEntry &TVEntry = Timeline[Index];
67     if (CurrentCycle < MaxCycle)
68       TVEntry.CycleRetired = CurrentCycle;
69 
70     // Update the WaitTime entry which corresponds to this Index.
71     assert(TVEntry.CycleDispatched >= 0 && "Invalid TVEntry found!");
72     unsigned CycleDispatched = static_cast<unsigned>(TVEntry.CycleDispatched);
73     WaitTimeEntry &WTEntry = WaitTime[Index % getSource().size()];
74     WTEntry.CyclesSpentInSchedulerQueue +=
75         TVEntry.CycleIssued - CycleDispatched;
76     assert(CycleDispatched <= TVEntry.CycleReady &&
77            "Instruction cannot be ready if it hasn't been dispatched yet!");
78     WTEntry.CyclesSpentInSQWhileReady +=
79         TVEntry.CycleIssued - TVEntry.CycleReady;
80     WTEntry.CyclesSpentAfterWBAndBeforeRetire +=
81         (CurrentCycle - 1) - TVEntry.CycleExecuted;
82     break;
83   }
84   case HWInstructionEvent::Ready:
85     Timeline[Index].CycleReady = CurrentCycle;
86     break;
87   case HWInstructionEvent::Issued:
88     Timeline[Index].CycleIssued = CurrentCycle;
89     break;
90   case HWInstructionEvent::Executed:
91     Timeline[Index].CycleExecuted = CurrentCycle;
92     break;
93   case HWInstructionEvent::Dispatched:
94     // There may be multiple dispatch events. Microcoded instructions that are
95     // expanded into multiple uOps may require multiple dispatch cycles. Here,
96     // we want to capture the first dispatch cycle.
97     if (Timeline[Index].CycleDispatched == -1)
98       Timeline[Index].CycleDispatched = static_cast<int>(CurrentCycle);
99     break;
100   default:
101     return;
102   }
103   if (CurrentCycle < MaxCycle)
104     LastCycle = std::max(LastCycle, CurrentCycle);
105 }
106 
107 static raw_ostream::Colors chooseColor(unsigned CumulativeCycles,
108                                        unsigned Executions, int BufferSize) {
109   if (CumulativeCycles && BufferSize < 0)
110     return raw_ostream::MAGENTA;
111   unsigned Size = static_cast<unsigned>(BufferSize);
112   if (CumulativeCycles >= Size * Executions)
113     return raw_ostream::RED;
114   if ((CumulativeCycles * 2) >= Size * Executions)
115     return raw_ostream::YELLOW;
116   return raw_ostream::SAVEDCOLOR;
117 }
118 
119 static void tryChangeColor(raw_ostream &OS, unsigned Cycles,
120                            unsigned Executions, int BufferSize) {
121   if (!OS.has_colors())
122     return;
123 
124   raw_ostream::Colors Color = chooseColor(Cycles, Executions, BufferSize);
125   if (Color == raw_ostream::SAVEDCOLOR) {
126     OS.resetColor();
127     return;
128   }
129   OS.changeColor(Color, /* bold */ true, /* BG */ false);
130 }
131 
132 void TimelineView::printWaitTimeEntry(formatted_raw_ostream &OS,
133                                       const WaitTimeEntry &Entry,
134                                       unsigned SourceIndex,
135                                       unsigned Executions) const {
136   bool PrintingTotals = SourceIndex == getSource().size();
137   unsigned CumulativeExecutions = PrintingTotals ? Timeline.size() : Executions;
138 
139   if (!PrintingTotals)
140     OS << SourceIndex << '.';
141 
142   OS.PadToColumn(7);
143 
144   double AverageTime1, AverageTime2, AverageTime3;
145   AverageTime1 =
146       (double)Entry.CyclesSpentInSchedulerQueue / CumulativeExecutions;
147   AverageTime2 = (double)Entry.CyclesSpentInSQWhileReady / CumulativeExecutions;
148   AverageTime3 =
149       (double)Entry.CyclesSpentAfterWBAndBeforeRetire / CumulativeExecutions;
150 
151   OS << Executions;
152   OS.PadToColumn(13);
153 
154   int BufferSize = PrintingTotals ? 0 : UsedBuffer[SourceIndex].second;
155   if (!PrintingTotals)
156     tryChangeColor(OS, Entry.CyclesSpentInSchedulerQueue, CumulativeExecutions,
157                    BufferSize);
158   OS << format("%.1f", floor((AverageTime1 * 10) + 0.5) / 10);
159   OS.PadToColumn(20);
160   if (!PrintingTotals)
161     tryChangeColor(OS, Entry.CyclesSpentInSQWhileReady, CumulativeExecutions,
162                    BufferSize);
163   OS << format("%.1f", floor((AverageTime2 * 10) + 0.5) / 10);
164   OS.PadToColumn(27);
165   if (!PrintingTotals)
166     tryChangeColor(OS, Entry.CyclesSpentAfterWBAndBeforeRetire,
167                    CumulativeExecutions,
168                    getSubTargetInfo().getSchedModel().MicroOpBufferSize);
169   OS << format("%.1f", floor((AverageTime3 * 10) + 0.5) / 10);
170 
171   if (OS.has_colors())
172     OS.resetColor();
173   OS.PadToColumn(34);
174 }
175 
176 void TimelineView::printAverageWaitTimes(raw_ostream &OS) const {
177   std::string Header =
178       "\n\nAverage Wait times (based on the timeline view):\n"
179       "[0]: Executions\n"
180       "[1]: Average time spent waiting in a scheduler's queue\n"
181       "[2]: Average time spent waiting in a scheduler's queue while ready\n"
182       "[3]: Average time elapsed from WB until retire stage\n\n"
183       "      [0]    [1]    [2]    [3]\n";
184   OS << Header;
185   formatted_raw_ostream FOS(OS);
186   unsigned Executions = Timeline.size() / getSource().size();
187   unsigned IID = 0;
188   for (const MCInst &Inst : getSource()) {
189     printWaitTimeEntry(FOS, WaitTime[IID], IID, Executions);
190     FOS << "   " << printInstructionString(Inst) << '\n';
191     FOS.flush();
192     ++IID;
193   }
194 
195   // If the timeline contains more than one instruction,
196   // let's also print global averages.
197   if (getSource().size() != 1) {
198     WaitTimeEntry TotalWaitTime = std::accumulate(
199         WaitTime.begin(), WaitTime.end(), WaitTimeEntry{0, 0, 0},
200         [](const WaitTimeEntry &A, const WaitTimeEntry &B) {
201           return WaitTimeEntry{
202               A.CyclesSpentInSchedulerQueue + B.CyclesSpentInSchedulerQueue,
203               A.CyclesSpentInSQWhileReady + B.CyclesSpentInSQWhileReady,
204               A.CyclesSpentAfterWBAndBeforeRetire +
205                   B.CyclesSpentAfterWBAndBeforeRetire};
206         });
207     printWaitTimeEntry(FOS, TotalWaitTime, IID, Executions);
208     FOS << "   "
209         << "<total>" << '\n';
210     FOS.flush();
211   }
212 }
213 
214 void TimelineView::printTimelineViewEntry(formatted_raw_ostream &OS,
215                                           const TimelineViewEntry &Entry,
216                                           unsigned Iteration,
217                                           unsigned SourceIndex) const {
218   if (Iteration == 0 && SourceIndex == 0)
219     OS << '\n';
220   OS << '[' << Iteration << ',' << SourceIndex << ']';
221   OS.PadToColumn(10);
222   assert(Entry.CycleDispatched >= 0 && "Invalid TimelineViewEntry!");
223   unsigned CycleDispatched = static_cast<unsigned>(Entry.CycleDispatched);
224   for (unsigned I = 0, E = CycleDispatched; I < E; ++I)
225     OS << ((I % 5 == 0) ? '.' : ' ');
226   OS << TimelineView::DisplayChar::Dispatched;
227   if (CycleDispatched != Entry.CycleExecuted) {
228     // Zero latency instructions have the same value for CycleDispatched,
229     // CycleIssued and CycleExecuted.
230     for (unsigned I = CycleDispatched + 1, E = Entry.CycleIssued; I < E; ++I)
231       OS << TimelineView::DisplayChar::Waiting;
232     if (Entry.CycleIssued == Entry.CycleExecuted)
233       OS << TimelineView::DisplayChar::DisplayChar::Executed;
234     else {
235       if (CycleDispatched != Entry.CycleIssued)
236         OS << TimelineView::DisplayChar::Executing;
237       for (unsigned I = Entry.CycleIssued + 1, E = Entry.CycleExecuted; I < E;
238            ++I)
239         OS << TimelineView::DisplayChar::Executing;
240       OS << TimelineView::DisplayChar::Executed;
241     }
242   }
243 
244   for (unsigned I = Entry.CycleExecuted + 1, E = Entry.CycleRetired; I < E; ++I)
245     OS << TimelineView::DisplayChar::RetireLag;
246   OS << TimelineView::DisplayChar::Retired;
247 
248   // Skip other columns.
249   for (unsigned I = Entry.CycleRetired + 1, E = LastCycle; I <= E; ++I)
250     OS << ((I % 5 == 0 || I == LastCycle) ? '.' : ' ');
251 }
252 
253 static void printTimelineHeader(formatted_raw_ostream &OS, unsigned Cycles) {
254   OS << "\n\nTimeline view:\n";
255   if (Cycles >= 10) {
256     OS.PadToColumn(10);
257     for (unsigned I = 0; I <= Cycles; ++I) {
258       if (((I / 10) & 1) == 0)
259         OS << ' ';
260       else
261         OS << I % 10;
262     }
263     OS << '\n';
264   }
265 
266   OS << "Index";
267   OS.PadToColumn(10);
268   for (unsigned I = 0; I <= Cycles; ++I) {
269     if (((I / 10) & 1) == 0)
270       OS << I % 10;
271     else
272       OS << ' ';
273   }
274   OS << '\n';
275 }
276 
277 void TimelineView::printTimeline(raw_ostream &OS) const {
278   formatted_raw_ostream FOS(OS);
279   printTimelineHeader(FOS, LastCycle);
280   FOS.flush();
281 
282   unsigned IID = 0;
283   ArrayRef<llvm::MCInst> Source = getSource();
284   const unsigned Iterations = Timeline.size() / Source.size();
285   for (unsigned Iteration = 0; Iteration < Iterations; ++Iteration) {
286     for (const MCInst &Inst : Source) {
287       const TimelineViewEntry &Entry = Timeline[IID];
288       if (Entry.CycleRetired == 0)
289         return;
290 
291       unsigned SourceIndex = IID % Source.size();
292       printTimelineViewEntry(FOS, Entry, Iteration, SourceIndex);
293       FOS << "   " << printInstructionString(Inst) << '\n';
294       FOS.flush();
295 
296       ++IID;
297     }
298   }
299 }
300 
301 json::Value TimelineView::toJSON() const {
302   json::Array TimelineInfo;
303 
304   for (const TimelineViewEntry &TLE : Timeline) {
305     TimelineInfo.push_back(
306         json::Object({{"CycleDispatched", TLE.CycleDispatched},
307                       {"CycleReady", TLE.CycleReady},
308                       {"CycleIssued", TLE.CycleIssued},
309                       {"CycleExecuted", TLE.CycleExecuted},
310                       {"CycleRetired", TLE.CycleRetired}}));
311   }
312   return json::Object({{"TimelineInfo", std::move(TimelineInfo)}});
313 }
314 } // namespace mca
315 } // namespace llvm
316