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