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
|
//===- PGOCtxProfWriter.cpp - Contextual Instrumentation profile writer ---===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Write a contextual profile to bitstream.
//
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/PGOCtxProfWriter.h"
#include "llvm/Bitstream/BitCodeEnums.h"
#include "llvm/ProfileData/CtxInstrContextNode.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
using namespace llvm::ctx_profile;
PGOCtxProfileWriter::PGOCtxProfileWriter(
raw_ostream &Out, std::optional<unsigned> VersionOverride)
: Writer(Out, 0) {
static_assert(ContainerMagic.size() == 4);
Out.write(ContainerMagic.data(), ContainerMagic.size());
Writer.EnterBlockInfoBlock();
{
auto DescribeBlock = [&](unsigned ID, StringRef Name) {
Writer.EmitRecord(bitc::BLOCKINFO_CODE_SETBID,
SmallVector<unsigned, 1>{ID});
Writer.EmitRecord(bitc::BLOCKINFO_CODE_BLOCKNAME,
llvm::arrayRefFromStringRef(Name));
};
SmallVector<uint64_t, 16> Data;
auto DescribeRecord = [&](unsigned RecordID, StringRef Name) {
Data.clear();
Data.push_back(RecordID);
llvm::append_range(Data, Name);
Writer.EmitRecord(bitc::BLOCKINFO_CODE_SETRECORDNAME, Data);
};
DescribeBlock(PGOCtxProfileBlockIDs::ProfileMetadataBlockID, "Metadata");
DescribeRecord(PGOCtxProfileRecords::Version, "Version");
DescribeBlock(PGOCtxProfileBlockIDs::ContextNodeBlockID, "Context");
DescribeRecord(PGOCtxProfileRecords::Guid, "GUID");
DescribeRecord(PGOCtxProfileRecords::CalleeIndex, "CalleeIndex");
DescribeRecord(PGOCtxProfileRecords::Counters, "Counters");
}
Writer.ExitBlock();
Writer.EnterSubblock(PGOCtxProfileBlockIDs::ProfileMetadataBlockID, CodeLen);
const auto Version = VersionOverride.value_or(CurrentVersion);
Writer.EmitRecord(PGOCtxProfileRecords::Version,
SmallVector<unsigned, 1>({Version}));
}
void PGOCtxProfileWriter::writeCounters(const ContextNode &Node) {
Writer.EmitCode(bitc::UNABBREV_RECORD);
Writer.EmitVBR(PGOCtxProfileRecords::Counters, VBREncodingBits);
Writer.EmitVBR(Node.counters_size(), VBREncodingBits);
for (uint32_t I = 0U; I < Node.counters_size(); ++I)
Writer.EmitVBR64(Node.counters()[I], VBREncodingBits);
}
// recursively write all the subcontexts. We do need to traverse depth first to
// model the context->subcontext implicitly, and since this captures call
// stacks, we don't really need to be worried about stack overflow and we can
// keep the implementation simple.
void PGOCtxProfileWriter::writeImpl(std::optional<uint32_t> CallerIndex,
const ContextNode &Node) {
Writer.EnterSubblock(PGOCtxProfileBlockIDs::ContextNodeBlockID, CodeLen);
Writer.EmitRecord(PGOCtxProfileRecords::Guid,
SmallVector<uint64_t, 1>{Node.guid()});
if (CallerIndex)
Writer.EmitRecord(PGOCtxProfileRecords::CalleeIndex,
SmallVector<uint64_t, 1>{*CallerIndex});
writeCounters(Node);
for (uint32_t I = 0U; I < Node.callsites_size(); ++I)
for (const auto *Subcontext = Node.subContexts()[I]; Subcontext;
Subcontext = Subcontext->next())
writeImpl(I, *Subcontext);
Writer.ExitBlock();
}
void PGOCtxProfileWriter::write(const ContextNode &RootNode) {
writeImpl(std::nullopt, RootNode);
}
namespace {
/// Representation of the context node suitable for yaml serialization /
/// deserialization.
struct SerializableCtxRepresentation {
ctx_profile::GUID Guid = 0;
std::vector<uint64_t> Counters;
std::vector<std::vector<SerializableCtxRepresentation>> Callsites;
};
ctx_profile::ContextNode *
createNode(std::vector<std::unique_ptr<char[]>> &Nodes,
const std::vector<SerializableCtxRepresentation> &DCList);
// Convert a DeserializableCtx into a ContextNode, potentially linking it to
// its sibling (e.g. callee at same callsite) "Next".
ctx_profile::ContextNode *
createNode(std::vector<std::unique_ptr<char[]>> &Nodes,
const SerializableCtxRepresentation &DC,
ctx_profile::ContextNode *Next = nullptr) {
auto AllocSize = ctx_profile::ContextNode::getAllocSize(DC.Counters.size(),
DC.Callsites.size());
auto *Mem = Nodes.emplace_back(std::make_unique<char[]>(AllocSize)).get();
std::memset(Mem, 0, AllocSize);
auto *Ret = new (Mem) ctx_profile::ContextNode(DC.Guid, DC.Counters.size(),
DC.Callsites.size(), Next);
std::memcpy(Ret->counters(), DC.Counters.data(),
sizeof(uint64_t) * DC.Counters.size());
for (const auto &[I, DCList] : llvm::enumerate(DC.Callsites))
Ret->subContexts()[I] = createNode(Nodes, DCList);
return Ret;
}
// Convert a list of SerializableCtxRepresentation into a linked list of
// ContextNodes.
ctx_profile::ContextNode *
createNode(std::vector<std::unique_ptr<char[]>> &Nodes,
const std::vector<SerializableCtxRepresentation> &DCList) {
ctx_profile::ContextNode *List = nullptr;
for (const auto &DC : DCList)
List = createNode(Nodes, DC, List);
return List;
}
} // namespace
LLVM_YAML_IS_SEQUENCE_VECTOR(SerializableCtxRepresentation)
LLVM_YAML_IS_SEQUENCE_VECTOR(std::vector<SerializableCtxRepresentation>)
template <> struct yaml::MappingTraits<SerializableCtxRepresentation> {
static void mapping(yaml::IO &IO, SerializableCtxRepresentation &SCR) {
IO.mapRequired("Guid", SCR.Guid);
IO.mapRequired("Counters", SCR.Counters);
IO.mapOptional("Callsites", SCR.Callsites);
}
};
Error llvm::createCtxProfFromYAML(StringRef Profile, raw_ostream &Out) {
yaml::Input In(Profile);
std::vector<SerializableCtxRepresentation> DCList;
In >> DCList;
if (In.error())
return createStringError(In.error(), "incorrect yaml content");
std::vector<std::unique_ptr<char[]>> Nodes;
std::error_code EC;
if (EC)
return createStringError(EC, "failed to open output");
PGOCtxProfileWriter Writer(Out);
for (const auto &DC : DCList) {
auto *TopList = createNode(Nodes, DC);
if (!TopList)
return createStringError(
"Unexpected error converting internal structure to ctx profile");
Writer.write(*TopList);
}
if (EC)
return createStringError(EC, "failed to write output");
return Error::success();
}
|
