llvm/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp

//===-- BenchmarkRunner.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
//
//===----------------------------------------------------------------------===//

#include "BenchmarkRunner.h"
#include "Assembler.h"
#include "Error.h"
#include "MCInstrDescView.h"
#include "MmapUtils.h"
#include "PerfHelper.h"
#include "SubprocessMemory.h"
#include "Target.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Config/llvm-config.h" // for LLVM_ON_UNIX
#include "llvm/Support/CrashRecoveryContext.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SystemZ/zOSSupport.h"
#include <cmath>
#include <memory>
#include <string>

#ifdef __linux__
#ifdef HAVE_LIBPFM
#include <perfmon/perf_event.h>
#endif
#include <sys/mman.h>
#include <sys/ptrace.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/syscall.h>
#include <sys/wait.h>
#include <unistd.h>

#if defined(__GLIBC__) && __has_include(<sys/rseq.h>) && defined(HAVE_BUILTIN_THREAD_POINTER)
#include <sys/rseq.h>
#if defined(RSEQ_SIG) && defined(SYS_rseq)
#define GLIBC_INITS_RSEQ
#endif
#endif
#endif // __linux__

namespace llvm {
namespace exegesis {

BenchmarkRunner::BenchmarkRunner(const LLVMState &State, Benchmark::ModeE Mode,
                                 BenchmarkPhaseSelectorE BenchmarkPhaseSelector,
                                 ExecutionModeE ExecutionMode,
                                 ArrayRef<ValidationEvent> ValCounters)
    : … { … }

BenchmarkRunner::~BenchmarkRunner() = default;

void BenchmarkRunner::FunctionExecutor::accumulateCounterValues(
    const SmallVectorImpl<int64_t> &NewValues,
    SmallVectorImpl<int64_t> *Result) { … }

Expected<SmallVector<int64_t, 4>>
BenchmarkRunner::FunctionExecutor::runAndSample(
    const char *Counters, ArrayRef<const char *> ValidationCounters,
    SmallVectorImpl<int64_t> &ValidationCounterValues) const { … }

namespace {
class InProcessFunctionExecutorImpl : public BenchmarkRunner::FunctionExecutor { … };

#ifdef __linux__
// The following class implements a function executor that executes the
// benchmark code within a subprocess rather than within the main llvm-exegesis
// process. This allows for much more control over the execution context of the
// snippet, particularly with regard to memory. This class performs all the
// necessary functions to create the subprocess, execute the snippet in the
// subprocess, and report results/handle errors.
class SubProcessFunctionExecutorImpl
    : public BenchmarkRunner::FunctionExecutor { … };
#endif // __linux__
} // namespace

Expected<SmallString<0>> BenchmarkRunner::assembleSnippet(
    const BenchmarkCode &BC, const SnippetRepetitor &Repetitor,
    unsigned MinInstructions, unsigned LoopBodySize,
    bool GenerateMemoryInstructions) const { … }

Expected<BenchmarkRunner::RunnableConfiguration>
BenchmarkRunner::getRunnableConfiguration(
    const BenchmarkCode &BC, unsigned MinInstructions, unsigned LoopBodySize,
    const SnippetRepetitor &Repetitor) const { … }

Expected<std::unique_ptr<BenchmarkRunner::FunctionExecutor>>
BenchmarkRunner::createFunctionExecutor(
    object::OwningBinary<object::ObjectFile> ObjectFile,
    const BenchmarkKey &Key) const { … }

std::pair<Error, Benchmark> BenchmarkRunner::runConfiguration(
    RunnableConfiguration &&RC,
    const std::optional<StringRef> &DumpFile) const { … }

Expected<std::string>
BenchmarkRunner::writeObjectFile(StringRef Buffer, StringRef FileName) const { … }

static bool EventLessThan(const std::pair<ValidationEvent, const char *> LHS,
                          const ValidationEvent RHS) { … }

Error BenchmarkRunner::getValidationCountersToRun(
    SmallVector<const char *> &ValCountersToRun) const { … }

BenchmarkRunner::FunctionExecutor::~FunctionExecutor() { … }

} // namespace exegesis
} // namespace llvm