libc/benchmarks/LibcBenchmark.cpp

//===-- Benchmark function -----------------------------------------------===//
//
// 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 "LibcBenchmark.h"
#include "llvm/ADT/StringRef.h"
#ifdef LIBC_BENCHMARKS_HAS_LLVM_SUPPORT
#include "llvm/TargetParser/Host.h"
#endif

namespace llvm {
namespace libc_benchmarks {

void checkRequirements() {
  const auto &CpuInfo = benchmark::CPUInfo::Get();
  if (CpuInfo.scaling == benchmark::CPUInfo::ENABLED)
    report_fatal_error(
        "CPU scaling is enabled, the benchmark real time measurements may be "
        "noisy and will incur extra overhead.");
}

HostState HostState::get() {
  const auto &cpu_info = benchmark::CPUInfo::Get();
  HostState h;
  h.cpu_frequency = cpu_info.cycles_per_second;
#ifdef LIBC_BENCHMARKS_HAS_LLVM_SUPPORT
  h.cpu_name = llvm::sys::getHostCPUName().str();
#else
  h.cpu_name = "";
#endif
  for (const auto &benchmark_cache_info : cpu_info.caches) {
    CacheInfo ci;
    ci.type = benchmark_cache_info.type;
    ci.level = benchmark_cache_info.level;
    ci.size = benchmark_cache_info.size;
    ci.num_sharing = benchmark_cache_info.num_sharing;
    h.caches.push_back(std::move(ci));
  }
  return h;
}

} // namespace libc_benchmarks
} // namespace llvm

#ifndef LIBC_BENCHMARKS_HAS_LLVM_SUPPORT
#include "llvm/ADT/Twine.h"
#include <cstdlib>
#include <iostream>
#include <string_view>
#if __has_include(<execinfo.h>)
#include <execinfo.h>
#include <unistd.h>
#endif

namespace llvm {
[[noreturn]] void report_fatal_error(std::string_view reason,
                                     bool gen_crash_diag) {
  std::cerr << "Fatal error: " << reason << std::endl;
#if __has_include(<execinfo.h>)
  if (gen_crash_diag) {
    void *buffer[64]{};
    int nptrs = ::backtrace(buffer, 64);
    ::backtrace_symbols_fd(buffer, nptrs, STDERR_FILENO);
  }
#endif
  std::abort();
}

[[noreturn]] void report_fatal_error(StringRef reason, bool gen_crash_diag) {
  report_fatal_error(std::string_view(reason.data(), reason.size()),
                     gen_crash_diag);
}
[[noreturn]] void report_fatal_error(const Twine &reason, bool gen_crash_diag) {
  report_fatal_error("(unknown twine error)", gen_crash_diag);
}
} // namespace llvm
#endif