1//=-- MemProfSummary.cpp - MemProf summary support ---------------=//
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//
9// This file contains MemProf summary support.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/ProfileData/MemProfSummary.h"
14
15using namespace llvm;
16using namespace llvm::memprof;
17
18void MemProfSummary::printSummaryYaml(raw_ostream &OS) const {
19 // For now emit as YAML comments, since they aren't read on input.
20 OS << "---\n";
21 OS << "# MemProfSummary:\n";
22 OS << "# Total contexts: " << NumContexts << "\n";
23 OS << "# Total cold contexts: " << NumColdContexts << "\n";
24 OS << "# Total hot contexts: " << NumHotContexts << "\n";
25 OS << "# Maximum cold context total size: " << MaxColdTotalSize << "\n";
26 OS << "# Maximum warm context total size: " << MaxWarmTotalSize << "\n";
27 OS << "# Maximum hot context total size: " << MaxHotTotalSize << "\n";
28 if (HasDataAccessProfile) {
29 OS << "# Num hot symbols and string literals: "
30 << NumHotSymbolsAndStringLiterals << "\n";
31 OS << "# Num known cold symbols: " << NumKnownColdSymbols << "\n";
32 OS << "# Num known cold string literals: " << NumKnownColdStringLiterals
33 << "\n";
34 }
35}
36
37void MemProfSummary::write(ProfOStream &OS) const {
38 // Write the current number of fields first, which helps enable backwards and
39 // forwards compatibility (see comment in header).
40 OS.write32(V: memprof::MemProfSummary::getNumSummaryFields());
41 auto StartPos = OS.tell();
42 (void)StartPos;
43 OS.write(V: NumContexts);
44 OS.write(V: NumColdContexts);
45 OS.write(V: NumHotContexts);
46 OS.write(V: MaxColdTotalSize);
47 OS.write(V: MaxWarmTotalSize);
48 OS.write(V: MaxHotTotalSize);
49 // Sanity check that the number of fields was kept in sync with actual fields.
50 assert((OS.tell() - StartPos) / 8 == MemProfSummary::getNumSummaryFields());
51}
52
53std::unique_ptr<MemProfSummary>
54MemProfSummary::deserialize(const unsigned char *&Ptr) {
55 auto NumSummaryFields =
56 support::endian::readNext<uint32_t, llvm::endianness::little>(memory&: Ptr);
57 // The initial version of the summary contains 6 fields. To support backwards
58 // compatibility with older profiles, if new summary fields are added (until a
59 // version bump) this code will need to check NumSummaryFields against the
60 // current value of MemProfSummary::getNumSummaryFields(). If NumSummaryFields
61 // is lower then default values will need to be filled in for the newer fields
62 // instead of trying to read them from the profile.
63 //
64 // For now, assert that the profile contains at least as many fields as
65 // expected by the code.
66 assert(NumSummaryFields >= MemProfSummary::getNumSummaryFields());
67
68 auto MemProfSum = std::make_unique<MemProfSummary>(
69 args: support::endian::read<uint64_t, llvm::endianness::little>(P: Ptr),
70 args: support::endian::read<uint64_t, llvm::endianness::little>(P: Ptr + 8),
71 args: support::endian::read<uint64_t, llvm::endianness::little>(P: Ptr + 16),
72 args: support::endian::read<uint64_t, llvm::endianness::little>(P: Ptr + 24),
73 args: support::endian::read<uint64_t, llvm::endianness::little>(P: Ptr + 32),
74 args: support::endian::read<uint64_t, llvm::endianness::little>(P: Ptr + 40));
75
76 // Enable forwards compatibility by skipping past any additional fields in the
77 // profile's summary.
78 Ptr += NumSummaryFields * sizeof(uint64_t);
79
80 return MemProfSum;
81}
82
83// FIXME: Consider to serialize the data access summary fields, ideally
84// batch this together with more substantial profile format change
85// and bump version once.
86void MemProfSummary::buildDataAccessSummary(
87 const DataAccessProfData &DataAccessProfile) {
88 HasDataAccessProfile = true;
89 NumHotSymbolsAndStringLiterals = DataAccessProfile.getRecords().size();
90 NumKnownColdSymbols = DataAccessProfile.getKnownColdSymbols().size();
91 NumKnownColdStringLiterals = DataAccessProfile.getKnownColdHashes().size();
92}
93