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| 1 | +//===- bolt/unittests/Profile/PerfSpeEvents.cpp ---------------------------===// |
| 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 | +#ifdef AARCH64_AVAILABLE |
| 10 | + |
| 11 | +#include "bolt/Core/BinaryContext.h" |
| 12 | +#include "bolt/Profile/DataAggregator.h" |
| 13 | +#include "llvm/BinaryFormat/ELF.h" |
| 14 | +#include "llvm/DebugInfo/DWARF/DWARFContext.h" |
| 15 | +#include "llvm/Support/CommandLine.h" |
| 16 | +#include "llvm/Support/TargetSelect.h" |
| 17 | +#include "gtest/gtest.h" |
| 18 | + |
| 19 | +using namespace llvm; |
| 20 | +using namespace llvm::bolt; |
| 21 | +using namespace llvm::object; |
| 22 | +using namespace llvm::ELF; |
| 23 | + |
| 24 | +namespace opts { |
| 25 | +extern cl::opt<std::string> ReadPerfEvents; |
| 26 | +extern cl::opt<bool> ArmSPE; |
| 27 | +} // namespace opts |
| 28 | + |
| 29 | +namespace llvm { |
| 30 | +namespace bolt { |
| 31 | + |
| 32 | +/// Perform checks on perf SPE branch events. |
| 33 | +struct PerfSpeEventsTestHelper : public testing::Test { |
| 34 | + void SetUp() override { |
| 35 | + initalizeLLVM(); |
| 36 | + prepareElf(); |
| 37 | + initializeBOLT(); |
| 38 | + } |
| 39 | + |
| 40 | +protected: |
| 41 | + using Trace = DataAggregator::Trace; |
| 42 | + using TakenBranchInfo = DataAggregator::TakenBranchInfo; |
| 43 | + |
| 44 | + void initalizeLLVM() { |
| 45 | + llvm::InitializeAllTargetInfos(); |
| 46 | + llvm::InitializeAllTargetMCs(); |
| 47 | + llvm::InitializeAllAsmParsers(); |
| 48 | + llvm::InitializeAllDisassemblers(); |
| 49 | + llvm::InitializeAllTargets(); |
| 50 | + llvm::InitializeAllAsmPrinters(); |
| 51 | + } |
| 52 | + |
| 53 | + void prepareElf() { |
| 54 | + memcpy(ElfBuf, "\177ELF", 4); |
| 55 | + ELF64LE::Ehdr *EHdr = reinterpret_cast<typename ELF64LE::Ehdr *>(ElfBuf); |
| 56 | + EHdr->e_ident[llvm::ELF::EI_CLASS] = llvm::ELF::ELFCLASS64; |
| 57 | + EHdr->e_ident[llvm::ELF::EI_DATA] = llvm::ELF::ELFDATA2LSB; |
| 58 | + EHdr->e_machine = llvm::ELF::EM_AARCH64; |
| 59 | + MemoryBufferRef Source(StringRef(ElfBuf, sizeof(ElfBuf)), "ELF"); |
| 60 | + ObjFile = cantFail(ObjectFile::createObjectFile(Source)); |
| 61 | + } |
| 62 | + |
| 63 | + void initializeBOLT() { |
| 64 | + Relocation::Arch = ObjFile->makeTriple().getArch(); |
| 65 | + BC = cantFail(BinaryContext::createBinaryContext( |
| 66 | + ObjFile->makeTriple(), std::make_shared<orc::SymbolStringPool>(), |
| 67 | + ObjFile->getFileName(), nullptr, /*IsPIC*/ false, |
| 68 | + DWARFContext::create(*ObjFile.get()), {llvm::outs(), llvm::errs()})); |
| 69 | + ASSERT_FALSE(!BC); |
| 70 | + } |
| 71 | + |
| 72 | + char ElfBuf[sizeof(typename ELF64LE::Ehdr)] = {}; |
| 73 | + std::unique_ptr<ObjectFile> ObjFile; |
| 74 | + std::unique_ptr<BinaryContext> BC; |
| 75 | + |
| 76 | + /// Helper function to export lists to show the mismatch. |
| 77 | + void reportBrStackEventMismatch( |
| 78 | + const std::vector<std::pair<Trace, TakenBranchInfo>> &Traces, |
| 79 | + const std::vector<std::pair<Trace, TakenBranchInfo>> &ExpectedSamples) { |
| 80 | + llvm::errs() << "Traces items: \n"; |
| 81 | + for (const auto &[Trace, BI] : Traces) |
| 82 | + llvm::errs() << "{" << Trace.Branch << ", " << Trace.From << "," |
| 83 | + << Trace.To << ", " << BI.TakenCount << ", " |
| 84 | + << BI.MispredCount << "}" << "\n"; |
| 85 | + |
| 86 | + llvm::errs() << "Expected items: \n"; |
| 87 | + for (const auto &[Trace, BI] : ExpectedSamples) |
| 88 | + llvm::errs() << "{" << Trace.Branch << ", " << Trace.From << ", " |
| 89 | + << Trace.To << ", " << BI.TakenCount << ", " |
| 90 | + << BI.MispredCount << "}" << "\n"; |
| 91 | + } |
| 92 | + |
| 93 | + /// Parse and check SPE brstack as LBR. |
| 94 | + void parseAndCheckBrstackEvents( |
| 95 | + uint64_t PID, |
| 96 | + const std::vector<std::pair<Trace, TakenBranchInfo>> &ExpectedSamples) { |
| 97 | + DataAggregator DA("<pseudo input>"); |
| 98 | + DA.ParsingBuf = opts::ReadPerfEvents; |
| 99 | + DA.BC = BC.get(); |
| 100 | + DataAggregator::MMapInfo MMap; |
| 101 | + DA.BinaryMMapInfo.insert(std::make_pair(PID, MMap)); |
| 102 | + |
| 103 | + DA.parseBranchEvents(); |
| 104 | + |
| 105 | + EXPECT_EQ(DA.Traces.size(), ExpectedSamples.size()); |
| 106 | + if (DA.Traces.size() != ExpectedSamples.size()) |
| 107 | + reportBrStackEventMismatch(DA.Traces, ExpectedSamples); |
| 108 | + |
| 109 | + const auto TracesBegin = DA.Traces.begin(); |
| 110 | + const auto TracesEnd = DA.Traces.end(); |
| 111 | + for (const auto &BI : ExpectedSamples) { |
| 112 | + auto it = find_if(TracesBegin, TracesEnd, |
| 113 | + [&BI](const auto &Tr) { return Tr.first == BI.first; }); |
| 114 | + |
| 115 | + EXPECT_NE(it, TracesEnd); |
| 116 | + EXPECT_EQ(it->second.MispredCount, BI.second.MispredCount); |
| 117 | + EXPECT_EQ(it->second.TakenCount, BI.second.TakenCount); |
| 118 | + } |
| 119 | + } |
| 120 | +}; |
| 121 | + |
| 122 | +} // namespace bolt |
| 123 | +} // namespace llvm |
| 124 | + |
| 125 | +TEST_F(PerfSpeEventsTestHelper, SpeBranchesWithBrstack) { |
| 126 | + // Check perf input with SPE branch events as brstack format. |
| 127 | + // Example collection command: |
| 128 | + // ``` |
| 129 | + // perf record -e 'arm_spe_0/branch_filter=1/u' -- BINARY |
| 130 | + // ``` |
| 131 | + // How Bolt extracts the branch events: |
| 132 | + // ``` |
| 133 | + // perf script -F pid,brstack --itrace=bl |
| 134 | + // ``` |
| 135 | + |
| 136 | + opts::ArmSPE = true; |
| 137 | + opts::ReadPerfEvents = " 1234 0xa001/0xa002/PN/-/-/10/COND/-\n" |
| 138 | + " 1234 0xb001/0xb002/P/-/-/4/RET/-\n" |
| 139 | + " 1234 0xc456/0xc789/P/-/-/13/-/-\n" |
| 140 | + " 1234 0xd123/0xd456/M/-/-/7/RET/-\n" |
| 141 | + " 1234 0xe001/0xe002/P/-/-/14/RET/-\n" |
| 142 | + " 1234 0xd123/0xd456/M/-/-/7/RET/-\n" |
| 143 | + " 1234 0xf001/0xf002/MN/-/-/8/COND/-\n" |
| 144 | + " 1234 0xc456/0xc789/M/-/-/13/-/-\n"; |
| 145 | + |
| 146 | + // ExpectedSamples contains the aggregated information about |
| 147 | + // a branch {{Branch From, To}, {TakenCount, MispredCount}}. |
| 148 | + // Consider this example trace: {{0xd123, 0xd456, Trace::BR_ONLY}, |
| 149 | + // {2,2}}. This entry has a TakenCount = 2, as we have two samples for |
| 150 | + // (0xd123, 0xd456) in our input. It also has MispredsCount = 2, |
| 151 | + // as 'M' misprediction flag appears in both cases. BR_ONLY means |
| 152 | + // the trace only contains branch data. |
| 153 | + std::vector<std::pair<Trace, TakenBranchInfo>> ExpectedSamples = { |
| 154 | + {{0xa001, 0xa002, Trace::BR_ONLY}, {1, 0}}, |
| 155 | + {{0xb001, 0xb002, Trace::BR_ONLY}, {1, 0}}, |
| 156 | + {{0xc456, 0xc789, Trace::BR_ONLY}, {2, 1}}, |
| 157 | + {{0xd123, 0xd456, Trace::BR_ONLY}, {2, 2}}, |
| 158 | + {{0xe001, 0xe002, Trace::BR_ONLY}, {1, 0}}, |
| 159 | + {{0xf001, 0xf002, Trace::BR_ONLY}, {1, 1}}}; |
| 160 | + |
| 161 | + parseAndCheckBrstackEvents(1234, ExpectedSamples); |
| 162 | +} |
| 163 | + |
| 164 | +#endif |
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