feat(third_party): add oatpp,googltest,benchmark

.gitea/workflows/build.yaml

@@ -0,0 +1,26 @@
+name: sm-rpc
+on:
+  push:
+  pull_request:
+  tags:
+    - v*
+jobs:
+  build:
+    strategy:
+      matrix:
+        toolchain:
+          - host.gcc
+          - aarch64-linux-gnu
+          - arm-linux-gnueabihf
+          - mipsel-linux-gnu
+        build_type: [Debug, Release]
+    runs-on: ubuntu-22.04
+    container:
+      image: tqcq/aw-centos:8
+    steps:
+      - uses: actions/checkout@v4
+      - name: build
+        run: |
+          mkdir -pv build && cd build
+          cmake .. -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DCMAKE_TOOLCHAIN_FILE=${TOOLCHAINS}/${{ matrix.toolchain }}.toolchain.cmake
+          make -j`nproc`

.gitignore

@@ -0,0 +1,3 @@
+compile_commands.json
+.cache
+build/

CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.10)
+project(demo LANGUAGES C CXX)
+
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+
+endif()
+
+add_subdirectory(third_party/oatpp)
+
+add_subdirectory(third_party/googletest)
+add_subdirectory(third_party/benchmark)
+
+enable_testing()
+add_executable(add_test src/add_test.cc)
+target_link_libraries(add_test PRIVATE GTest::gtest_main)
+
+add_executable(add_benchmark src/add_benchmark.cc)
+target_link_libraries(add_benchmark PRIVATE benchmark::benchmark)

src/add.h

@@ -0,0 +1,11 @@
+#ifndef __ADD_H__
+#define __ADD_H__
+
+template<typename T>
+T
+Add(const T &a, const T &b)
+{
+    return a + b;
+}
+
+#endif// __ADD_H__

src/add_benchmark.cc

@@ -0,0 +1,12 @@
+#include "add.h"
+#include <benchmark/benchmark.h>
+
+static void
+BM_Add(benchmark::State &state)
+{
+    Add(1, 2);
+}
+
+BENCHMARK(BM_Add);
+
+BENCHMARK_MAIN();

src/add_test.cc

@@ -0,0 +1,8 @@
+#include "add.h"
+#include <gtest/gtest.h>
+
+TEST(Add, Base)
+{
+    EXPECT_EQ(Add(1, 2), 3);
+    EXPECT_EQ(Add(1, -2), -1);
+}

third_party/benchmark/.clang-format

@@ -0,0 +1,5 @@
+---
+Language:        Cpp
+BasedOnStyle:  Google
+PointerAlignment: Left
+...

third_party/benchmark/.clang-tidy

@@ -0,0 +1,6 @@
+---
+Checks:          'clang-analyzer-*,readability-redundant-*,performance-*'
+WarningsAsErrors: 'clang-analyzer-*,readability-redundant-*,performance-*'
+HeaderFilterRegex: '.*'
+FormatStyle:     none
+User:            user

third_party/benchmark/.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,32 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: "[BUG]"
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**System**
+Which OS, compiler, and compiler version are you using:
+  - OS: 
+  - Compiler and version: 
+
+**To reproduce**
+Steps to reproduce the behavior:
+1. sync to commit ...
+2. cmake/bazel...
+3. make ...
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Additional context**
+Add any other context about the problem here.

third_party/benchmark/.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: "[FR]"
+labels: ''
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

third_party/benchmark/.github/install_bazel.sh

@@ -0,0 +1,12 @@
+if ! bazel version; then
+  arch=$(uname -m)
+  if [ "$arch" == "aarch64" ]; then
+    arch="arm64"
+  fi
+  echo "Downloading $arch Bazel binary from GitHub releases."
+  curl -L -o $HOME/bin/bazel --create-dirs "https://github.com/bazelbuild/bazel/releases/download/7.1.1/bazel-7.1.1-linux-$arch"
+  chmod +x $HOME/bin/bazel
+else
+  # Bazel is installed for the correct architecture
+  exit 0
+fi

third_party/benchmark/.github/libcxx-setup.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+set -e
+
+# Checkout LLVM sources
+git clone --depth=1 --branch llvmorg-16.0.6 https://github.com/llvm/llvm-project.git llvm-project
+
+## Setup libc++ options
+if [ -z "$BUILD_32_BITS" ]; then
+  export BUILD_32_BITS=OFF && echo disabling 32 bit build
+fi
+
+## Build and install libc++ (Use unstable ABI for better sanitizer coverage)
+mkdir llvm-build && cd llvm-build
+cmake -DCMAKE_C_COMPILER=${CC}                  \
+      -DCMAKE_CXX_COMPILER=${CXX}               \
+      -DCMAKE_BUILD_TYPE=RelWithDebInfo         \
+      -DCMAKE_INSTALL_PREFIX=/usr               \
+      -DLIBCXX_ABI_UNSTABLE=OFF                 \
+      -DLLVM_USE_SANITIZER=${LIBCXX_SANITIZER}  \
+      -DLLVM_BUILD_32_BITS=${BUILD_32_BITS}     \
+      -DLLVM_ENABLE_RUNTIMES='libcxx;libcxxabi;libunwind' \
+      -G "Unix Makefiles" \
+      ../llvm-project/runtimes/
+make -j cxx cxxabi unwind
+cd ..

third_party/benchmark/.github/workflows/bazel.yml

@@ -0,0 +1,35 @@
+name: bazel
+
+on:
+  push: {}
+  pull_request: {}
+
+jobs:
+  build_and_test_default:
+    name: bazel.${{ matrix.os }}.${{ matrix.bzlmod && 'bzlmod' || 'no_bzlmod' }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        bzlmod: [false, true]
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: mount bazel cache
+      uses: actions/cache@v3
+      env:
+        cache-name: bazel-cache
+      with:
+        path: "~/.cache/bazel"
+        key: ${{ env.cache-name }}-${{ matrix.os }}-${{ github.ref }}
+        restore-keys: |
+          ${{ env.cache-name }}-${{ matrix.os }}-main
+
+    - name: build
+      run: |
+        bazel build ${{ matrix.bzlmod && '--enable_bzlmod' || '--noenable_bzlmod' }} //:benchmark //:benchmark_main //test/...
+
+    - name: test
+      run: |
+        bazel test ${{ matrix.bzlmod && '--enable_bzlmod' || '--noenable_bzlmod' }} --test_output=all //test/...

third_party/benchmark/.github/workflows/build-and-test-min-cmake.yml

@@ -0,0 +1,46 @@
+name: build-and-test-min-cmake
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  job:
+    name: ${{ matrix.os }}.min-cmake
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: lukka/get-cmake@latest
+        with:
+          cmakeVersion: 3.10.0
+
+      - name: create build environment
+        run: cmake -E make_directory ${{ runner.workspace }}/_build
+
+      - name: setup cmake initial cache
+        run: touch compiler-cache.cmake
+
+      - name: configure cmake
+        env:
+          CXX: ${{ matrix.compiler }}
+        shell: bash
+        working-directory: ${{ runner.workspace }}/_build
+        run: >
+          cmake -C ${{ github.workspace }}/compiler-cache.cmake
+          $GITHUB_WORKSPACE
+          -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+          -DCMAKE_CXX_VISIBILITY_PRESET=hidden
+          -DCMAKE_VISIBILITY_INLINES_HIDDEN=ON
+
+      - name: build
+        shell: bash
+        working-directory: ${{ runner.workspace }}/_build
+        run: cmake --build .

third_party/benchmark/.github/workflows/build-and-test-perfcounters.yml

@@ -0,0 +1,51 @@
+name: build-and-test-perfcounters
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  job:
+    # TODO(dominic): Extend this to include compiler and set through env: CC/CXX.
+    name: ${{ matrix.os }}.${{ matrix.build_type }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-22.04, ubuntu-20.04]
+        build_type: ['Release', 'Debug']
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: install libpfm
+      run: |
+        sudo apt update
+        sudo apt -y install libpfm4-dev
+
+    - name: create build environment
+      run: cmake -E make_directory ${{ runner.workspace }}/_build
+
+    - name: configure cmake
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: >
+        cmake $GITHUB_WORKSPACE
+        -DBENCHMARK_ENABLE_LIBPFM=1
+        -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+        -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+
+    - name: build
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: cmake --build . --config ${{ matrix.build_type }}
+
+    # Skip testing, for now. It seems perf_event_open does not succeed on the
+    # hosting machine, very likely a permissions issue.
+    # TODO(mtrofin): Enable test.
+    # - name: test
+    #   shell: bash
+    #   working-directory: ${{ runner.workspace }}/_build
+    #   run: ctest -C ${{ matrix.build_type }} --rerun-failed --output-on-failure
+

third_party/benchmark/.github/workflows/build-and-test.yml

@@ -0,0 +1,161 @@
+name: build-and-test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  # TODO: add 32-bit builds (g++ and clang++) for ubuntu
+  #   (requires g++-multilib and libc6:i386)
+  # TODO: add coverage build (requires lcov)
+  # TODO: add clang + libc++ builds for ubuntu
+  job:
+    name: ${{ matrix.os }}.${{ matrix.build_type }}.${{ matrix.lib }}.${{ matrix.compiler }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-22.04, ubuntu-20.04, macos-latest]
+        build_type: ['Release', 'Debug']
+        compiler: ['g++', 'clang++']
+        lib: ['shared', 'static']
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: lukka/get-cmake@latest
+
+      - name: create build environment
+        run: cmake -E make_directory ${{ runner.workspace }}/_build
+
+      - name: setup cmake initial cache
+        run: touch compiler-cache.cmake
+
+      - name: configure cmake
+        env:
+          CXX: ${{ matrix.compiler }}
+        shell: bash
+        working-directory: ${{ runner.workspace }}/_build
+        run: >
+          cmake -C ${{ github.workspace }}/compiler-cache.cmake
+          $GITHUB_WORKSPACE
+          -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+          -DBUILD_SHARED_LIBS=${{ matrix.lib == 'shared' }}
+          -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+          -DCMAKE_CXX_COMPILER=${{ env.CXX }}
+          -DCMAKE_CXX_VISIBILITY_PRESET=hidden
+          -DCMAKE_VISIBILITY_INLINES_HIDDEN=ON
+
+      - name: build
+        shell: bash
+        working-directory: ${{ runner.workspace }}/_build
+        run: cmake --build . --config ${{ matrix.build_type }}
+
+      - name: test
+        shell: bash
+        working-directory: ${{ runner.workspace }}/_build
+        run: ctest -C ${{ matrix.build_type }} -VV
+
+  msvc:
+    name: ${{ matrix.os }}.${{ matrix.build_type }}.${{ matrix.lib }}.${{ matrix.msvc }}
+    runs-on: ${{ matrix.os }}
+    defaults:
+        run:
+            shell: powershell
+    strategy:
+      fail-fast: false
+      matrix:
+        msvc:
+          - VS-16-2019
+          - VS-17-2022
+        arch:
+          - x64
+        build_type:
+          - Debug
+          - Release
+        lib:
+          - shared
+          - static
+        include:
+          - msvc: VS-16-2019
+            os: windows-2019
+            generator: 'Visual Studio 16 2019'
+          - msvc: VS-17-2022
+            os: windows-2022
+            generator: 'Visual Studio 17 2022'
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: lukka/get-cmake@latest
+
+      - name: configure cmake
+        run: >
+          cmake -S . -B _build/
+          -A ${{ matrix.arch }}
+          -G "${{ matrix.generator }}"
+          -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+          -DBUILD_SHARED_LIBS=${{ matrix.lib == 'shared' }}
+
+      - name: build
+        run: cmake --build _build/ --config ${{ matrix.build_type }}
+
+      - name: test
+        run: ctest --test-dir _build/ -C ${{ matrix.build_type }} -VV
+
+  msys2:
+    name: ${{ matrix.os }}.${{ matrix.build_type }}.${{ matrix.lib }}.${{ matrix.msys2.msystem }}
+    runs-on: ${{ matrix.os }}
+    defaults:
+        run:
+            shell: msys2 {0}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ windows-latest ]
+        msys2:
+          - { msystem: MINGW64,    arch: x86_64,  family: GNU,  compiler: g++ }
+          - { msystem: MINGW32,    arch: i686,    family: GNU,  compiler: g++ }
+          - { msystem: CLANG64,    arch: x86_64,  family: LLVM, compiler: clang++ }
+          - { msystem: CLANG32,    arch: i686,    family: LLVM, compiler: clang++ }
+          - { msystem: UCRT64,     arch: x86_64,  family: GNU,  compiler: g++ }
+        build_type:
+          - Debug
+          - Release
+        lib:
+          - shared
+          - static
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install Base Dependencies
+        uses: msys2/setup-msys2@v2
+        with:
+          cache: false
+          msystem: ${{ matrix.msys2.msystem }}
+          update: true
+          install: >-
+            git
+            base-devel
+          pacboy: >-
+            cc:p
+            cmake:p
+            ninja:p
+
+      - name: configure cmake
+        env:
+          CXX: ${{ matrix.msys2.compiler }}
+        run: >
+          cmake -S . -B _build/
+          -GNinja
+          -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+          -DBUILD_SHARED_LIBS=${{ matrix.lib == 'shared' }}
+
+      - name: build
+        run: cmake --build _build/ --config ${{ matrix.build_type }}
+
+      - name: test
+        run: ctest --test-dir _build/ -C ${{ matrix.build_type }} -VV

third_party/benchmark/.github/workflows/clang-format-lint.yml

@@ -0,0 +1,18 @@
+name: clang-format-lint
+on:
+  push: {}
+  pull_request: {}
+
+jobs:
+  job:
+    name: check-clang-format
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - uses: DoozyX/clang-format-lint-action@v0.13
+      with:
+        source: './include/benchmark ./src ./test'
+        extensions: 'h,cc'
+        clangFormatVersion: 12
+        style: Google

third_party/benchmark/.github/workflows/clang-tidy.yml

@@ -0,0 +1,38 @@
+name: clang-tidy
+
+on:
+  push: {}
+  pull_request: {}
+
+jobs:
+  job:
+    name: run-clang-tidy
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: install clang-tidy
+      run: sudo apt update && sudo apt -y install clang-tidy
+
+    - name: create build environment
+      run: cmake -E make_directory ${{ runner.workspace }}/_build
+
+    - name: configure cmake
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: >
+        cmake $GITHUB_WORKSPACE
+        -DBENCHMARK_ENABLE_ASSEMBLY_TESTS=OFF
+        -DBENCHMARK_ENABLE_LIBPFM=OFF
+        -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+        -DCMAKE_C_COMPILER=clang
+        -DCMAKE_CXX_COMPILER=clang++
+        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+        -DGTEST_COMPILE_COMMANDS=OFF
+
+    - name: run
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: run-clang-tidy

third_party/benchmark/.github/workflows/doxygen.yml

@@ -0,0 +1,28 @@
+name: doxygen
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build-and-deploy:
+    name: Build HTML documentation
+    runs-on: ubuntu-latest
+    steps:
+    - name: Fetching sources
+      uses: actions/checkout@v3
+
+    - name: Installing build dependencies
+      run: |
+        sudo apt update
+        sudo apt install doxygen gcc git
+
+    - name: Creating build directory
+      run: mkdir build
+
+    - name: Building HTML documentation with Doxygen
+      run: |
+        cmake -S . -B build -DBENCHMARK_ENABLE_TESTING:BOOL=OFF -DBENCHMARK_ENABLE_DOXYGEN:BOOL=ON -DBENCHMARK_INSTALL_DOCS:BOOL=ON
+        cmake --build build --target benchmark_doxygen

third_party/benchmark/.github/workflows/pre-commit.yml

@@ -0,0 +1,38 @@
+name: python + Bazel pre-commit checks
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    env:
+      MYPY_CACHE_DIR: "${{ github.workspace }}/.cache/mypy"
+      RUFF_CACHE_DIR: "${{ github.workspace }}/.cache/ruff"
+      PRE_COMMIT_HOME: "${{ github.workspace }}/.cache/pre-commit"
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: 3.11
+        cache: pip
+        cache-dependency-path: pyproject.toml
+    - name: Install dependencies
+      run: python -m pip install ".[dev]"
+    - name: Cache pre-commit tools
+      uses: actions/cache@v3
+      with:
+        path: |
+          ${{ env.MYPY_CACHE_DIR }}
+          ${{ env.RUFF_CACHE_DIR }}
+          ${{ env.PRE_COMMIT_HOME }}
+        key: ${{ runner.os }}-${{ hashFiles('.pre-commit-config.yaml') }}-linter-cache
+    - name: Run pre-commit checks
+      run: pre-commit run --all-files --verbose --show-diff-on-failure

third_party/benchmark/.github/workflows/sanitizer.yml

@@ -0,0 +1,96 @@
+name: sanitizer
+
+on:
+  push: {}
+  pull_request: {}
+
+env:
+  UBSAN_OPTIONS: "print_stacktrace=1"
+
+jobs:
+  job:
+    name: ${{ matrix.sanitizer }}.${{ matrix.build_type }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        build_type: ['Debug', 'RelWithDebInfo']
+        sanitizer: ['asan', 'ubsan', 'tsan', 'msan']
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: configure msan env
+      if: matrix.sanitizer == 'msan'
+      run: |
+        echo "EXTRA_FLAGS=-g -O2 -fno-omit-frame-pointer -fsanitize=memory -fsanitize-memory-track-origins" >> $GITHUB_ENV
+        echo "LIBCXX_SANITIZER=MemoryWithOrigins" >> $GITHUB_ENV
+
+    - name: configure ubsan env
+      if: matrix.sanitizer == 'ubsan'
+      run: |
+        echo "EXTRA_FLAGS=-g -O2 -fno-omit-frame-pointer -fsanitize=undefined -fno-sanitize-recover=all" >> $GITHUB_ENV
+        echo "LIBCXX_SANITIZER=Undefined" >> $GITHUB_ENV
+
+    - name: configure asan env
+      if: matrix.sanitizer == 'asan'
+      run: |
+        echo "EXTRA_FLAGS=-g -O2 -fno-omit-frame-pointer -fsanitize=address -fno-sanitize-recover=all" >> $GITHUB_ENV
+        echo "LIBCXX_SANITIZER=Address" >> $GITHUB_ENV
+
+    - name: configure tsan env
+      if: matrix.sanitizer == 'tsan'
+      run: |
+        echo "EXTRA_FLAGS=-g -O2 -fno-omit-frame-pointer -fsanitize=thread -fno-sanitize-recover=all" >> $GITHUB_ENV
+        echo "LIBCXX_SANITIZER=Thread" >> $GITHUB_ENV
+
+    - name: fine-tune asan options
+      # in asan we get an error from std::regex. ignore it.
+      if: matrix.sanitizer == 'asan'
+      run: |
+        echo "ASAN_OPTIONS=alloc_dealloc_mismatch=0" >> $GITHUB_ENV
+
+    - name: setup clang
+      uses: egor-tensin/setup-clang@v1
+      with:
+        version: latest
+        platform: x64
+
+    - name: configure clang
+      run: |
+        echo "CC=cc" >> $GITHUB_ENV
+        echo "CXX=c++" >> $GITHUB_ENV
+
+    - name: build libc++ (non-asan)
+      if: matrix.sanitizer != 'asan'
+      run: |
+        "${GITHUB_WORKSPACE}/.github/libcxx-setup.sh"
+        echo "EXTRA_CXX_FLAGS=-stdlib=libc++ -L ${GITHUB_WORKSPACE}/llvm-build/lib -lc++abi -Isystem${GITHUB_WORKSPACE}/llvm-build/include -Isystem${GITHUB_WORKSPACE}/llvm-build/include/c++/v1 -Wl,-rpath,${GITHUB_WORKSPACE}/llvm-build/lib" >> $GITHUB_ENV
+
+    - name: create build environment
+      run: cmake -E make_directory ${{ runner.workspace }}/_build
+
+    - name: configure cmake
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: >
+        VERBOSE=1
+        cmake $GITHUB_WORKSPACE
+        -DBENCHMARK_ENABLE_ASSEMBLY_TESTS=OFF
+        -DBENCHMARK_ENABLE_LIBPFM=OFF
+        -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON
+        -DCMAKE_C_COMPILER=${{ env.CC }}
+        -DCMAKE_CXX_COMPILER=${{ env.CXX }}
+        -DCMAKE_C_FLAGS="${{ env.EXTRA_FLAGS }}"
+        -DCMAKE_CXX_FLAGS="${{ env.EXTRA_FLAGS }} ${{ env.EXTRA_CXX_FLAGS }}"
+        -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+
+    - name: build
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: cmake --build . --config ${{ matrix.build_type }}
+
+    - name: test
+      shell: bash
+      working-directory: ${{ runner.workspace }}/_build
+      run: ctest -C ${{ matrix.build_type }} -VV

third_party/benchmark/.github/workflows/test_bindings.yml

@@ -0,0 +1,30 @@
+name: test-bindings
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  python_bindings:
+    name: Test GBM Python bindings on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ ubuntu-latest, macos-latest, windows-latest ]
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Set up Python 3.11
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.11
+      - name: Install GBM Python bindings on ${{ matrix.os }}
+        run: python -m pip install .
+      - name: Run bindings example on ${{ matrix.os }}
+        run:
+          python bindings/python/google_benchmark/example.py

third_party/benchmark/.github/workflows/wheels.yml

@@ -0,0 +1,90 @@
+name: Build and upload Python wheels
+
+on:
+  workflow_dispatch:
+  release:
+    types:
+      - published
+
+jobs:
+  build_sdist:
+    name: Build source distribution
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Install Python 3.12
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.12
+      - run: python -m pip install build
+      - name: Build sdist
+        run: python -m build --sdist
+      - uses: actions/upload-artifact@v4
+        with:
+          name: dist-sdist
+          path: dist/*.tar.gz
+
+  build_wheels:
+    name: Build Google Benchmark wheels on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-13, macos-14, windows-latest]
+
+    steps:
+      - name: Check out Google Benchmark
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up QEMU
+        if: runner.os == 'Linux'
+        uses: docker/setup-qemu-action@v3
+        with:
+          platforms: all
+
+      - name: Build wheels on ${{ matrix.os }} using cibuildwheel
+        uses: pypa/cibuildwheel@v2.17
+        env:
+          CIBW_BUILD: "cp38-* cp39-* cp310-* cp311-* cp312-*"
+          CIBW_SKIP: "*-musllinux_*"
+          CIBW_TEST_SKIP: "cp38-macosx_*:arm64"
+          CIBW_ARCHS_LINUX: auto64 aarch64
+          CIBW_ARCHS_WINDOWS: auto64
+          CIBW_BEFORE_ALL_LINUX: bash .github/install_bazel.sh
+          # Grab the rootless Bazel installation inside the container.
+          CIBW_ENVIRONMENT_LINUX: PATH=$PATH:$HOME/bin
+          CIBW_TEST_COMMAND: python {project}/bindings/python/google_benchmark/example.py
+
+      - name: Upload Google Benchmark ${{ matrix.os }} wheels
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist-${{ matrix.os }}
+          path: wheelhouse/*.whl
+
+  merge_wheels:
+    name: Merge all built wheels into one artifact
+    runs-on: ubuntu-latest
+    needs: build_wheels
+    steps:
+      - name: Merge wheels
+        uses: actions/upload-artifact/merge@v4
+        with:
+          name: dist
+          pattern: dist-*
+          delete-merged: true
+
+  pypi_upload:
+    name: Publish google-benchmark wheels to PyPI
+    needs: [merge_wheels]
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          path: dist
+      - uses: pypa/gh-action-pypi-publish@v1

third_party/benchmark/.gitignore

@@ -0,0 +1,68 @@
+*.a
+*.so
+*.so.?*
+*.dll
+*.exe
+*.dylib
+*.cmake
+!/cmake/*.cmake
+!/test/AssemblyTests.cmake
+*~
+*.swp
+*.pyc
+__pycache__
+.DS_Store
+
+# lcov
+*.lcov
+/lcov
+
+# cmake files.
+/Testing
+CMakeCache.txt
+CMakeFiles/
+cmake_install.cmake
+
+# makefiles.
+Makefile
+
+# in-source build.
+bin/
+lib/
+/test/*_test
+
+# exuberant ctags.
+tags
+
+# YouCompleteMe configuration.
+.ycm_extra_conf.pyc
+
+# ninja generated files.
+.ninja_deps
+.ninja_log
+build.ninja
+install_manifest.txt
+rules.ninja
+
+# bazel output symlinks.
+bazel-*
+MODULE.bazel.lock
+
+# out-of-source build top-level folders.
+build/
+_build/
+build*/
+
+# in-source dependencies
+/googletest/
+
+# Visual Studio 2015/2017 cache/options directory
+.vs/
+CMakeSettings.json
+
+# Visual Studio Code cache/options directory
+.vscode/
+
+# Python build stuff
+dist/
+*.egg-info*

third_party/benchmark/.pre-commit-config.yaml

@@ -0,0 +1,18 @@
+repos:
+  -   repo: https://github.com/keith/pre-commit-buildifier
+      rev: 6.4.0
+      hooks:
+      -   id: buildifier
+      -   id: buildifier-lint
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.8.0
+    hooks:
+      - id: mypy
+        types_or: [ python, pyi ]
+        args: [ "--ignore-missing-imports", "--scripts-are-modules" ]
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.3.1
+    hooks:
+      - id: ruff
+        args: [ --fix, --exit-non-zero-on-fix ]
+      - id: ruff-format

third_party/benchmark/.travis.yml

@@ -0,0 +1,208 @@
+sudo: required
+dist: trusty
+language: cpp
+
+matrix:
+  include:
+    - compiler: gcc
+      addons:
+        apt:
+          packages:
+            - lcov
+      env: COMPILER=g++ C_COMPILER=gcc BUILD_TYPE=Coverage
+    - compiler: gcc
+      addons:
+        apt:
+          packages:
+            - g++-multilib
+            - libc6:i386
+      env:
+        - COMPILER=g++
+        - C_COMPILER=gcc
+        - BUILD_TYPE=Debug
+        - BUILD_32_BITS=ON
+        - EXTRA_FLAGS="-m32"
+    - compiler: gcc
+      addons:
+        apt:
+          packages:
+            - g++-multilib
+            - libc6:i386
+      env:
+        - COMPILER=g++
+        - C_COMPILER=gcc
+        - BUILD_TYPE=Release
+        - BUILD_32_BITS=ON
+        - EXTRA_FLAGS="-m32"
+    - compiler: gcc
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=g++-6 C_COMPILER=gcc-6  BUILD_TYPE=Debug
+        - ENABLE_SANITIZER=1
+        - EXTRA_FLAGS="-fno-omit-frame-pointer -g -O2 -fsanitize=undefined,address -fuse-ld=gold"
+    # Clang w/ libc++
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            clang-3.8
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=Debug
+        - LIBCXX_BUILD=1
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            clang-3.8
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=Release
+        - LIBCXX_BUILD=1
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+    # Clang w/ 32bit libc++
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            - clang-3.8
+            - g++-multilib
+            - libc6:i386
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=Debug
+        - LIBCXX_BUILD=1
+        - BUILD_32_BITS=ON
+        - EXTRA_FLAGS="-m32"
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+    # Clang w/ 32bit libc++
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            - clang-3.8
+            - g++-multilib
+            - libc6:i386
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=Release
+        - LIBCXX_BUILD=1
+        - BUILD_32_BITS=ON
+        - EXTRA_FLAGS="-m32"
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+    # Clang w/ libc++, ASAN, UBSAN
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            clang-3.8
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=Debug
+        - LIBCXX_BUILD=1 LIBCXX_SANITIZER="Undefined;Address"
+        - ENABLE_SANITIZER=1
+        - EXTRA_FLAGS="-g -O2 -fno-omit-frame-pointer -fsanitize=undefined,address -fno-sanitize-recover=all"
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+        - UBSAN_OPTIONS=print_stacktrace=1
+    # Clang w/ libc++ and MSAN
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            clang-3.8
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=Debug
+        - LIBCXX_BUILD=1 LIBCXX_SANITIZER=MemoryWithOrigins
+        - ENABLE_SANITIZER=1
+        - EXTRA_FLAGS="-g -O2 -fno-omit-frame-pointer -fsanitize=memory -fsanitize-memory-track-origins"
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+    # Clang w/ libc++ and MSAN
+    - compiler: clang
+      dist: xenial
+      addons:
+        apt:
+          packages:
+            clang-3.8
+      env:
+        - INSTALL_GCC6_FROM_PPA=1
+        - COMPILER=clang++-3.8 C_COMPILER=clang-3.8 BUILD_TYPE=RelWithDebInfo
+        - LIBCXX_BUILD=1 LIBCXX_SANITIZER=Thread
+        - ENABLE_SANITIZER=1
+        - EXTRA_FLAGS="-g -O2 -fno-omit-frame-pointer -fsanitize=thread -fno-sanitize-recover=all"
+        - EXTRA_CXX_FLAGS="-stdlib=libc++"
+    - os: osx
+      osx_image: xcode8.3
+      compiler: clang
+      env:
+        - COMPILER=clang++
+        - BUILD_TYPE=Release
+        - BUILD_32_BITS=ON
+        - EXTRA_FLAGS="-m32"
+
+before_script:
+  - if [ -n "${LIBCXX_BUILD}" ]; then
+      source .libcxx-setup.sh;
+    fi
+  - if [ -n "${ENABLE_SANITIZER}" ]; then
+      export EXTRA_OPTIONS="-DBENCHMARK_ENABLE_ASSEMBLY_TESTS=OFF";
+    else
+      export EXTRA_OPTIONS="";
+    fi
+  - mkdir -p build && cd build
+
+before_install:
+  - if [ -z "$BUILD_32_BITS" ]; then
+      export BUILD_32_BITS=OFF && echo disabling 32 bit build;
+    fi
+  - if [ -n "${INSTALL_GCC6_FROM_PPA}" ]; then
+      sudo add-apt-repository -y "ppa:ubuntu-toolchain-r/test";
+      sudo apt-get update --option Acquire::Retries=100 --option Acquire::http::Timeout="60";
+    fi
+
+install:
+  - if [ -n "${INSTALL_GCC6_FROM_PPA}" ]; then
+      travis_wait sudo -E apt-get -yq --no-install-suggests --no-install-recommends install g++-6;
+    fi
+  - if [ "${TRAVIS_OS_NAME}" == "linux" -a "${BUILD_32_BITS}" == "OFF" ]; then
+      travis_wait sudo -E apt-get -y --no-install-suggests --no-install-recommends install llvm-3.9-tools;
+      sudo cp /usr/lib/llvm-3.9/bin/FileCheck /usr/local/bin/;
+    fi
+  - if [ "${BUILD_TYPE}" == "Coverage" -a "${TRAVIS_OS_NAME}" == "linux" ]; then
+      PATH=~/.local/bin:${PATH};
+      pip install --user --upgrade pip;
+      travis_wait pip install --user cpp-coveralls;
+    fi
+  - if [ "${C_COMPILER}" == "gcc-7" -a "${TRAVIS_OS_NAME}" == "osx" ]; then
+      rm -f /usr/local/include/c++;
+      brew update;
+      travis_wait brew install gcc@7;
+    fi
+  - if [ "${TRAVIS_OS_NAME}" == "linux" ]; then
+      sudo apt-get update -qq;
+      sudo apt-get install -qq unzip cmake3;
+      wget https://github.com/bazelbuild/bazel/releases/download/3.2.0/bazel-3.2.0-installer-linux-x86_64.sh --output-document bazel-installer.sh;
+      travis_wait sudo bash bazel-installer.sh;
+    fi
+  - if [ "${TRAVIS_OS_NAME}" == "osx" ]; then
+      curl -L -o bazel-installer.sh https://github.com/bazelbuild/bazel/releases/download/3.2.0/bazel-3.2.0-installer-darwin-x86_64.sh;
+      travis_wait sudo bash bazel-installer.sh;
+    fi
+
+script:
+  - cmake -DCMAKE_C_COMPILER=${C_COMPILER} -DCMAKE_CXX_COMPILER=${COMPILER} -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DCMAKE_C_FLAGS="${EXTRA_FLAGS}" -DCMAKE_CXX_FLAGS="${EXTRA_FLAGS} ${EXTRA_CXX_FLAGS}" -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON -DBENCHMARK_BUILD_32_BITS=${BUILD_32_BITS} ${EXTRA_OPTIONS} ..
+  - make
+  - ctest -C ${BUILD_TYPE} --output-on-failure
+  - bazel test -c dbg --define google_benchmark.have_regex=posix --announce_rc --verbose_failures --test_output=errors --keep_going //test/...
+
+after_success:
+  - if [ "${BUILD_TYPE}" == "Coverage" -a "${TRAVIS_OS_NAME}" == "linux" ]; then
+      coveralls --include src --include include --gcov-options '\-lp' --root .. --build-root .;
+    fi

third_party/benchmark/.ycm_extra_conf.py

@@ -0,0 +1,120 @@
+import os
+
+import ycm_core
+
+# These are the compilation flags that will be used in case there's no
+# compilation database set (by default, one is not set).
+# CHANGE THIS LIST OF FLAGS. YES, THIS IS THE DROID YOU HAVE BEEN LOOKING FOR.
+flags = [
+    "-Wall",
+    "-Werror",
+    "-pedantic-errors",
+    "-std=c++0x",
+    "-fno-strict-aliasing",
+    "-O3",
+    "-DNDEBUG",
+    # ...and the same thing goes for the magic -x option which specifies the
+    # language that the files to be compiled are written in. This is mostly
+    # relevant for c++ headers.
+    # For a C project, you would set this to 'c' instead of 'c++'.
+    "-x",
+    "c++",
+    "-I",
+    "include",
+    "-isystem",
+    "/usr/include",
+    "-isystem",
+    "/usr/local/include",
+]
+
+
+# Set this to the absolute path to the folder (NOT the file!) containing the
+# compile_commands.json file to use that instead of 'flags'. See here for
+# more details: http://clang.llvm.org/docs/JSONCompilationDatabase.html
+#
+# Most projects will NOT need to set this to anything; you can just change the
+# 'flags' list of compilation flags. Notice that YCM itself uses that approach.
+compilation_database_folder = ""
+
+if os.path.exists(compilation_database_folder):
+    database = ycm_core.CompilationDatabase(compilation_database_folder)
+else:
+    database = None
+
+SOURCE_EXTENSIONS = [".cc"]
+
+
+def DirectoryOfThisScript():
+    return os.path.dirname(os.path.abspath(__file__))
+
+
+def MakeRelativePathsInFlagsAbsolute(flags, working_directory):
+    if not working_directory:
+        return list(flags)
+    new_flags = []
+    make_next_absolute = False
+    path_flags = ["-isystem", "-I", "-iquote", "--sysroot="]
+    for flag in flags:
+        new_flag = flag
+
+        if make_next_absolute:
+            make_next_absolute = False
+            if not flag.startswith("/"):
+                new_flag = os.path.join(working_directory, flag)
+
+        for path_flag in path_flags:
+            if flag == path_flag:
+                make_next_absolute = True
+                break
+
+            if flag.startswith(path_flag):
+                path = flag[len(path_flag) :]
+                new_flag = path_flag + os.path.join(working_directory, path)
+                break
+
+        if new_flag:
+            new_flags.append(new_flag)
+    return new_flags
+
+
+def IsHeaderFile(filename):
+    extension = os.path.splitext(filename)[1]
+    return extension in [".h", ".hxx", ".hpp", ".hh"]
+
+
+def GetCompilationInfoForFile(filename):
+    # The compilation_commands.json file generated by CMake does not have entries
+    # for header files. So we do our best by asking the db for flags for a
+    # corresponding source file, if any. If one exists, the flags for that file
+    # should be good enough.
+    if IsHeaderFile(filename):
+        basename = os.path.splitext(filename)[0]
+        for extension in SOURCE_EXTENSIONS:
+            replacement_file = basename + extension
+            if os.path.exists(replacement_file):
+                compilation_info = database.GetCompilationInfoForFile(
+                    replacement_file
+                )
+                if compilation_info.compiler_flags_:
+                    return compilation_info
+        return None
+    return database.GetCompilationInfoForFile(filename)
+
+
+def FlagsForFile(filename, **kwargs):
+    if database:
+        # Bear in mind that compilation_info.compiler_flags_ does NOT return a
+        # python list, but a "list-like" StringVec object
+        compilation_info = GetCompilationInfoForFile(filename)
+        if not compilation_info:
+            return None
+
+        final_flags = MakeRelativePathsInFlagsAbsolute(
+            compilation_info.compiler_flags_,
+            compilation_info.compiler_working_dir_,
+        )
+    else:
+        relative_to = DirectoryOfThisScript()
+        final_flags = MakeRelativePathsInFlagsAbsolute(flags, relative_to)
+
+    return {"flags": final_flags, "do_cache": True}

third_party/benchmark/AUTHORS

@@ -0,0 +1,72 @@
+# This is the official list of benchmark authors for copyright purposes.
+# This file is distinct from the CONTRIBUTORS files.
+# See the latter for an explanation.
+#
+# Names should be added to this file as:
+#	Name or Organization <email address>
+# The email address is not required for organizations.
+#
+# Please keep the list sorted.
+
+Albert Pretorius <pretoalb@gmail.com>
+Alex Steele <steeleal123@gmail.com>
+Andriy Berestovskyy <berestovskyy@gmail.com>
+Arne Beer <arne@twobeer.de>
+Carto
+Cezary Skrzyński <czars1988@gmail.com>
+Christian Wassermann <christian_wassermann@web.de>
+Christopher Seymour <chris.j.seymour@hotmail.com>
+Colin Braley <braley.colin@gmail.com>
+Daniel Harvey <danielharvey458@gmail.com>
+David Coeurjolly <david.coeurjolly@liris.cnrs.fr>
+Deniz Evrenci <denizevrenci@gmail.com>
+Dirac Research 
+Dominik Czarnota <dominik.b.czarnota@gmail.com>
+Dominik Korman <kormandominik@gmail.com>
+Donald Aingworth <donalds_junk_mail@yahoo.com>
+Eric Backus <eric_backus@alum.mit.edu>
+Eric Fiselier <eric@efcs.ca>
+Eugene Zhuk <eugene.zhuk@gmail.com>
+Evgeny Safronov <division494@gmail.com>
+Fabien Pichot <pichot.fabien@gmail.com>
+Federico Ficarelli <federico.ficarelli@gmail.com>
+Felix Homann <linuxaudio@showlabor.de>
+Gergely Meszaros <maetveis@gmail.com>
+Gergő Szitár <szitar.gergo@gmail.com>
+Google Inc.
+Henrique Bucher <hbucher@gmail.com>
+International Business Machines Corporation
+Ismael Jimenez Martinez <ismael.jimenez.martinez@gmail.com>
+Jern-Kuan Leong <jernkuan@gmail.com>
+JianXiong Zhou <zhoujianxiong2@gmail.com>
+Joao Paulo Magalhaes <joaoppmagalhaes@gmail.com>
+Jordan Williams <jwillikers@protonmail.com>
+Jussi Knuuttila <jussi.knuuttila@gmail.com>
+Kaito Udagawa <umireon@gmail.com>
+Kishan Kumar <kumar.kishan@outlook.com>
+Lei Xu <eddyxu@gmail.com>
+Marcel Jacobse <mjacobse@uni-bremen.de>
+Matt Clarkson <mattyclarkson@gmail.com>
+Maxim Vafin <maxvafin@gmail.com>
+Mike Apodaca <gatorfax@gmail.com>
+Min-Yih Hsu <yihshyng223@gmail.com>
+MongoDB Inc.
+Nick Hutchinson <nshutchinson@gmail.com>
+Norman Heino <norman.heino@gmail.com>
+Oleksandr Sochka <sasha.sochka@gmail.com>
+Ori Livneh <ori.livneh@gmail.com>
+Paul Redmond <paul.redmond@gmail.com>
+Radoslav Yovchev <radoslav.tm@gmail.com>
+Raghu Raja <raghu@enfabrica.net>
+Rainer Orth <ro@cebitec.uni-bielefeld.de>
+Roman Lebedev <lebedev.ri@gmail.com>
+Sayan Bhattacharjee <aero.sayan@gmail.com>
+Shapr3D <google-contributors@shapr3d.com>
+Shuo Chen <chenshuo@chenshuo.com>
+Staffan Tjernstrom <staffantj@gmail.com>
+Steinar H. Gunderson <sgunderson@bigfoot.com>
+Stripe, Inc.
+Tobias Schmidt <tobias.schmidt@in.tum.de>
+Yixuan Qiu <yixuanq@gmail.com>
+Yusuke Suzuki <utatane.tea@gmail.com>
+Zbigniew Skowron <zbychs@gmail.com>

third_party/benchmark/BUILD.bazel

@@ -0,0 +1,114 @@
+licenses(["notice"])
+
+COPTS = [
+    "-pedantic",
+    "-pedantic-errors",
+    "-std=c++11",
+    "-Wall",
+    "-Wconversion",
+    "-Wextra",
+    "-Wshadow",
+    #    "-Wshorten-64-to-32",
+    "-Wfloat-equal",
+    "-fstrict-aliasing",
+    ## assert() are used a lot in tests upstream, which may be optimised out leading to
+    ## unused-variable warning.
+    "-Wno-unused-variable",
+    "-Werror=old-style-cast",
+]
+
+config_setting(
+    name = "qnx",
+    constraint_values = ["@platforms//os:qnx"],
+    values = {
+        "cpu": "x64_qnx",
+    },
+    visibility = [":__subpackages__"],
+)
+
+config_setting(
+    name = "windows",
+    constraint_values = ["@platforms//os:windows"],
+    values = {
+        "cpu": "x64_windows",
+    },
+    visibility = [":__subpackages__"],
+)
+
+config_setting(
+    name = "macos",
+    constraint_values = ["@platforms//os:macos"],
+    visibility = ["//visibility:public"],
+)
+
+config_setting(
+    name = "perfcounters",
+    define_values = {
+        "pfm": "1",
+    },
+    visibility = [":__subpackages__"],
+)
+
+cc_library(
+    name = "benchmark",
+    srcs = glob(
+        [
+            "src/*.cc",
+            "src/*.h",
+        ],
+        exclude = ["src/benchmark_main.cc"],
+    ),
+    hdrs = [
+        "include/benchmark/benchmark.h",
+        "include/benchmark/export.h",
+    ],
+    copts = select({
+        ":windows": [],
+        "//conditions:default": COPTS,
+    }),
+    defines = [
+        "BENCHMARK_STATIC_DEFINE",
+        "BENCHMARK_VERSION=\\\"" + (module_version() if module_version() != None else "") + "\\\"",
+    ] + select({
+        ":perfcounters": ["HAVE_LIBPFM"],
+        "//conditions:default": [],
+    }),
+    linkopts = select({
+        ":windows": ["-DEFAULTLIB:shlwapi.lib"],
+        "//conditions:default": ["-pthread"],
+    }),
+    # Only static linking is allowed; no .so will be produced.
+    # Using `defines` (i.e. not `local_defines`) means that no
+    # dependent rules need to bother about defining the macro.
+    linkstatic = True,
+    local_defines = [
+        # Turn on Large-file Support
+        "_FILE_OFFSET_BITS=64",
+        "_LARGEFILE64_SOURCE",
+        "_LARGEFILE_SOURCE",
+    ],
+    strip_include_prefix = "include",
+    visibility = ["//visibility:public"],
+    deps = select({
+        ":perfcounters": ["@libpfm"],
+        "//conditions:default": [],
+    }),
+)
+
+cc_library(
+    name = "benchmark_main",
+    srcs = ["src/benchmark_main.cc"],
+    hdrs = [
+        "include/benchmark/benchmark.h",
+        "include/benchmark/export.h",
+    ],
+    strip_include_prefix = "include",
+    visibility = ["//visibility:public"],
+    deps = [":benchmark"],
+)
+
+cc_library(
+    name = "benchmark_internal_headers",
+    hdrs = glob(["src/*.h"]),
+    visibility = ["//test:__pkg__"],
+)

third_party/benchmark/CMakeLists.txt

@@ -0,0 +1,431 @@
+# Require CMake 3.10. If available, use the policies up to CMake 3.22.
+cmake_minimum_required(VERSION 3.10...3.22)
+
+project(
+  benchmark
+  VERSION 1.8.4
+  LANGUAGES CXX)
+
+option(BENCHMARK_ENABLE_TESTING "Enable testing of the benchmark library." OFF)
+option(BENCHMARK_ENABLE_EXCEPTIONS
+       "Enable the use of exceptions in the benchmark library." ON)
+option(BENCHMARK_ENABLE_LTO
+       "Enable link time optimisation of the benchmark library." OFF)
+option(BENCHMARK_USE_LIBCXX
+       "Build and test using libc++ as the standard library." OFF)
+option(BENCHMARK_ENABLE_WERROR "Build Release candidates with -Werror." ON)
+option(BENCHMARK_FORCE_WERROR
+       "Build Release candidates with -Werror regardless of compiler issues."
+       OFF)
+
+if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "PGI")
+  # PGC++ maybe reporting false positives.
+  set(BENCHMARK_ENABLE_WERROR OFF)
+endif()
+if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "NVHPC")
+  set(BENCHMARK_ENABLE_WERROR OFF)
+endif()
+if(BENCHMARK_FORCE_WERROR)
+  set(BENCHMARK_ENABLE_WERROR ON)
+endif(BENCHMARK_FORCE_WERROR)
+
+if(NOT (MSVC OR CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC"))
+  option(BENCHMARK_BUILD_32_BITS "Build a 32 bit version of the library." OFF)
+else()
+  set(BENCHMARK_BUILD_32_BITS
+      OFF
+      CACHE
+        BOOL
+        "Build a 32 bit version of the library - unsupported when using MSVC)"
+        FORCE)
+endif()
+option(
+  BENCHMARK_ENABLE_INSTALL
+  "Enable installation of benchmark. (Projects embedding benchmark may want to turn this OFF.)"
+  OFF)
+option(BENCHMARK_ENABLE_DOXYGEN "Build documentation with Doxygen." OFF)
+option(BENCHMARK_INSTALL_DOCS "Enable installation of documentation." OFF)
+
+# Allow unmet dependencies to be met using CMake's ExternalProject mechanics,
+# which may require downloading the source code.
+option(BENCHMARK_DOWNLOAD_DEPENDENCIES
+       "Allow the downloading and in-tree building of unmet dependencies" OFF)
+
+# This option can be used to disable building and running unit tests which
+# depend on gtest in cases where it is not possible to build or find a valid
+# version of gtest.
+option(BENCHMARK_ENABLE_GTEST_TESTS
+       "Enable building the unit tests which depend on gtest" OFF)
+option(
+  BENCHMARK_USE_BUNDLED_GTEST
+  "Use bundled GoogleTest. If disabled, the find_package(GTest) will be used."
+  ON)
+
+option(BENCHMARK_ENABLE_LIBPFM "Enable performance counters provided by libpfm"
+       OFF)
+
+# Export only public symbols
+set(CMAKE_CXX_VISIBILITY_PRESET hidden)
+set(CMAKE_VISIBILITY_INLINES_HIDDEN ON)
+
+if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+  # As of CMake 3.18, CMAKE_SYSTEM_PROCESSOR is not set properly for MSVC and
+  # cross-compilation (e.g. Host=x86_64, target=aarch64) requires using the
+  # undocumented, but working variable. See
+  # https://gitlab.kitware.com/cmake/cmake/-/issues/15170
+  set(CMAKE_SYSTEM_PROCESSOR ${MSVC_CXX_ARCHITECTURE_ID})
+  if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "ARM")
+    set(CMAKE_CROSSCOMPILING TRUE)
+  endif()
+endif()
+
+set(ENABLE_ASSEMBLY_TESTS_DEFAULT OFF)
+function(should_enable_assembly_tests)
+  if(CMAKE_BUILD_TYPE)
+    string(TOLOWER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE_LOWER)
+    if(${CMAKE_BUILD_TYPE_LOWER} MATCHES "coverage")
+      # FIXME: The --coverage flag needs to be removed when building assembly
+      # tests for this to work.
+      return()
+    endif()
+  endif()
+  if(MSVC OR CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")
+    return()
+  elseif(NOT CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64")
+    return()
+  elseif(NOT CMAKE_SIZEOF_VOID_P EQUAL 8)
+    # FIXME: Make these work on 32 bit builds
+    return()
+  elseif(BENCHMARK_BUILD_32_BITS)
+    # FIXME: Make these work on 32 bit builds
+    return()
+  endif()
+  find_program(LLVM_FILECHECK_EXE FileCheck)
+  if(LLVM_FILECHECK_EXE)
+    set(LLVM_FILECHECK_EXE
+        "${LLVM_FILECHECK_EXE}"
+        CACHE PATH "llvm filecheck" FORCE)
+    message(STATUS "LLVM FileCheck Found: ${LLVM_FILECHECK_EXE}")
+  else()
+    message(STATUS "Failed to find LLVM FileCheck")
+    return()
+  endif()
+  set(ENABLE_ASSEMBLY_TESTS_DEFAULT
+      ON
+      PARENT_SCOPE)
+endfunction()
+should_enable_assembly_tests()
+
+# This option disables the building and running of the assembly verification
+# tests
+option(BENCHMARK_ENABLE_ASSEMBLY_TESTS
+       "Enable building and running the assembly tests"
+       ${ENABLE_ASSEMBLY_TESTS_DEFAULT})
+
+# Make sure we can import out CMake functions
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules")
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+
+# Read the git tags to determine the project version
+include(GetGitVersion)
+get_git_version(GIT_VERSION)
+
+# If no git version can be determined, use the version from the project()
+# command
+if("${GIT_VERSION}" STREQUAL "0.0.0")
+  set(VERSION "v${benchmark_VERSION}")
+else()
+  set(VERSION "${GIT_VERSION}")
+endif()
+
+# Normalize version: drop "v" prefix, replace first "-" with ".", drop
+# everything after second "-" (including said "-").
+string(STRIP ${VERSION} VERSION)
+if(VERSION MATCHES v[^-]*-)
+  string(REGEX REPLACE "v([^-]*)-([0-9]+)-.*" "\\1.\\2" NORMALIZED_VERSION
+                       ${VERSION})
+else()
+  string(REGEX REPLACE "v(.*)" "\\1" NORMALIZED_VERSION ${VERSION})
+endif()
+
+# Tell the user what versions we are using
+message(
+  STATUS
+    "Google Benchmark version: ${VERSION}, normalized to ${NORMALIZED_VERSION}")
+
+# The version of the libraries
+set(GENERIC_LIB_VERSION ${NORMALIZED_VERSION})
+string(SUBSTRING ${NORMALIZED_VERSION} 0 1 GENERIC_LIB_SOVERSION)
+
+# Import our CMake modules
+include(AddCXXCompilerFlag)
+include(CheckCXXCompilerFlag)
+include(CheckLibraryExists)
+include(CXXFeatureCheck)
+
+check_library_exists(rt shm_open "" HAVE_LIB_RT)
+
+if(BENCHMARK_BUILD_32_BITS)
+  add_required_cxx_compiler_flag(-m32)
+endif()
+
+if(MSVC OR CMAKE_CXX_SIMULATE_ID STREQUAL "MSVC")
+  set(BENCHMARK_CXX_STANDARD 14)
+else()
+  set(BENCHMARK_CXX_STANDARD 11)
+endif()
+
+set(CMAKE_CXX_STANDARD ${BENCHMARK_CXX_STANDARD})
+set(CMAKE_CXX_STANDARD_REQUIRED YES)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+if(MSVC)
+  # Turn compiler warnings up to 11
+  string(REGEX REPLACE "[-/]W[1-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+  add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+
+  if(NOT BENCHMARK_ENABLE_EXCEPTIONS)
+    add_cxx_compiler_flag(-EHs-)
+    add_cxx_compiler_flag(-EHa-)
+    add_definitions(-D_HAS_EXCEPTIONS=0)
+  endif()
+  # Link time optimisation
+  if(BENCHMARK_ENABLE_LTO)
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /GL")
+    set(CMAKE_STATIC_LINKER_FLAGS_RELEASE
+        "${CMAKE_STATIC_LINKER_FLAGS_RELEASE} /LTCG")
+    set(CMAKE_SHARED_LINKER_FLAGS_RELEASE
+        "${CMAKE_SHARED_LINKER_FLAGS_RELEASE} /LTCG")
+    set(CMAKE_EXE_LINKER_FLAGS_RELEASE
+        "${CMAKE_EXE_LINKER_FLAGS_RELEASE} /LTCG")
+
+    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /GL")
+    string(
+      REGEX
+      REPLACE "[-/]INCREMENTAL" "/INCREMENTAL:NO"
+              CMAKE_STATIC_LINKER_FLAGS_RELWITHDEBINFO
+              "${CMAKE_STATIC_LINKER_FLAGS_RELWITHDEBINFO}")
+    set(CMAKE_STATIC_LINKER_FLAGS_RELWITHDEBINFO
+        "${CMAKE_STATIC_LINKER_FLAGS_RELWITHDEBINFO} /LTCG")
+    string(
+      REGEX
+      REPLACE "[-/]INCREMENTAL" "/INCREMENTAL:NO"
+              CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO
+              "${CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO}")
+    set(CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO
+        "${CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO} /LTCG")
+    string(
+      REGEX
+      REPLACE "[-/]INCREMENTAL" "/INCREMENTAL:NO"
+              CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO
+              "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO}")
+    set(CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO
+        "${CMAKE_EXE_LINKER_FLAGS_RELWITHDEBINFO} /LTCG")
+
+    set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} /GL")
+    set(CMAKE_STATIC_LINKER_FLAGS_MINSIZEREL
+        "${CMAKE_STATIC_LINKER_FLAGS_MINSIZEREL} /LTCG")
+    set(CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL
+        "${CMAKE_SHARED_LINKER_FLAGS_MINSIZEREL} /LTCG")
+    set(CMAKE_EXE_LINKER_FLAGS_MINSIZEREL
+        "${CMAKE_EXE_LINKER_FLAGS_MINSIZEREL} /LTCG")
+  endif()
+else()
+  # Turn on Large-file Support
+  add_definitions(-D_FILE_OFFSET_BITS=64)
+  add_definitions(-D_LARGEFILE64_SOURCE)
+  add_definitions(-D_LARGEFILE_SOURCE)
+  # Turn compiler warnings up to 11
+  add_cxx_compiler_flag(-Wall)
+  add_cxx_compiler_flag(-Wextra)
+  add_cxx_compiler_flag(-Wshadow)
+  add_cxx_compiler_flag(-Wfloat-equal)
+  add_cxx_compiler_flag(-Wold-style-cast)
+  add_cxx_compiler_flag(-Wconversion)
+  if(BENCHMARK_ENABLE_WERROR)
+    add_cxx_compiler_flag(-Werror)
+  endif()
+  if(NOT BENCHMARK_ENABLE_TESTING)
+    # Disable warning when compiling tests as gtest does not use 'override'.
+    add_cxx_compiler_flag(-Wsuggest-override)
+  endif()
+  add_cxx_compiler_flag(-pedantic)
+  add_cxx_compiler_flag(-pedantic-errors)
+  add_cxx_compiler_flag(-Wshorten-64-to-32)
+  add_cxx_compiler_flag(-fstrict-aliasing)
+  # Disable warnings regarding deprecated parts of the library while building
+  # and testing those parts of the library.
+  add_cxx_compiler_flag(-Wno-deprecated-declarations)
+  if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel" OR CMAKE_CXX_COMPILER_ID STREQUAL
+                                               "IntelLLVM")
+    # Intel silently ignores '-Wno-deprecated-declarations', warning no. 1786
+    # must be explicitly disabled. See #631 for rationale.
+    add_cxx_compiler_flag(-wd1786)
+    add_cxx_compiler_flag(-fno-finite-math-only)
+  endif()
+  # Disable deprecation warnings for release builds (when -Werror is enabled).
+  if(BENCHMARK_ENABLE_WERROR)
+    add_cxx_compiler_flag(-Wno-deprecated)
+  endif()
+  if(NOT BENCHMARK_ENABLE_EXCEPTIONS)
+    add_cxx_compiler_flag(-fno-exceptions)
+  endif()
+
+  if(HAVE_CXX_FLAG_FSTRICT_ALIASING)
+    if(NOT CMAKE_CXX_COMPILER_ID STREQUAL "Intel" AND NOT CMAKE_CXX_COMPILER_ID
+                                                      STREQUAL "IntelLLVM"
+    )# ICC17u2: Many false positives for Wstrict-aliasing
+      add_cxx_compiler_flag(-Wstrict-aliasing)
+    endif()
+  endif()
+  # ICC17u2: overloaded virtual function "benchmark::Fixture::SetUp" is only
+  # partially overridden (because of deprecated overload)
+  add_cxx_compiler_flag(-wd654)
+  add_cxx_compiler_flag(-Wthread-safety)
+  if(HAVE_CXX_FLAG_WTHREAD_SAFETY)
+    cxx_feature_check(THREAD_SAFETY_ATTRIBUTES
+                      "-DINCLUDE_DIRECTORIES=${PROJECT_SOURCE_DIR}/include")
+  endif()
+
+  # On most UNIX like platforms g++ and clang++ define _GNU_SOURCE as a
+  # predefined macro, which turns on all of the wonderful libc extensions.
+  # However g++ doesn't do this in Cygwin so we have to define it ourselves
+  # since we depend on GNU/POSIX/BSD extensions.
+  if(CYGWIN)
+    add_definitions(-D_GNU_SOURCE=1)
+  endif()
+
+  if(QNXNTO)
+    add_definitions(-D_QNX_SOURCE)
+  endif()
+
+  # Link time optimisation
+  if(BENCHMARK_ENABLE_LTO)
+    add_cxx_compiler_flag(-flto)
+    add_cxx_compiler_flag(-Wno-lto-type-mismatch)
+    if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+      find_program(GCC_AR gcc-ar)
+      if(GCC_AR)
+        set(CMAKE_AR ${GCC_AR})
+      endif()
+      find_program(GCC_RANLIB gcc-ranlib)
+      if(GCC_RANLIB)
+        set(CMAKE_RANLIB ${GCC_RANLIB})
+      endif()
+    elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+      include(llvm-toolchain)
+    endif()
+  endif()
+
+  # Coverage build type
+  set(BENCHMARK_CXX_FLAGS_COVERAGE
+      "${CMAKE_CXX_FLAGS_DEBUG}"
+      CACHE STRING "Flags used by the C++ compiler during coverage builds."
+            FORCE)
+  set(BENCHMARK_EXE_LINKER_FLAGS_COVERAGE
+      "${CMAKE_EXE_LINKER_FLAGS_DEBUG}"
+      CACHE STRING "Flags used for linking binaries during coverage builds."
+            FORCE)
+  set(BENCHMARK_SHARED_LINKER_FLAGS_COVERAGE
+      "${CMAKE_SHARED_LINKER_FLAGS_DEBUG}"
+      CACHE STRING
+            "Flags used by the shared libraries linker during coverage builds."
+            FORCE)
+  mark_as_advanced(
+    BENCHMARK_CXX_FLAGS_COVERAGE BENCHMARK_EXE_LINKER_FLAGS_COVERAGE
+    BENCHMARK_SHARED_LINKER_FLAGS_COVERAGE)
+  set(CMAKE_BUILD_TYPE
+      "${CMAKE_BUILD_TYPE}"
+      CACHE
+        STRING
+        "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel Coverage."
+  )
+  add_cxx_compiler_flag(--coverage COVERAGE)
+endif()
+
+if(BENCHMARK_USE_LIBCXX)
+  if("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+    add_cxx_compiler_flag(-stdlib=libc++)
+  elseif(
+    "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU"
+    OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel"
+    OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "IntelLLVM")
+    add_cxx_compiler_flag(-nostdinc++)
+    message(
+      WARNING
+        "libc++ header path must be manually specified using CMAKE_CXX_FLAGS")
+    # Adding -nodefaultlibs directly to CMAKE_<TYPE>_LINKER_FLAGS will break
+    # configuration checks such as 'find_package(Threads)'
+    list(APPEND BENCHMARK_CXX_LINKER_FLAGS -nodefaultlibs)
+    # -lc++ cannot be added directly to CMAKE_<TYPE>_LINKER_FLAGS because linker
+    # flags appear before all linker inputs and -lc++ must appear after.
+    list(APPEND BENCHMARK_CXX_LIBRARIES c++)
+  else()
+    message(
+      FATAL_ERROR "-DBENCHMARK_USE_LIBCXX:BOOL=ON is not supported for compiler"
+    )
+  endif()
+endif(BENCHMARK_USE_LIBCXX)
+
+set(EXTRA_CXX_FLAGS "")
+if(WIN32 AND "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+  # Clang on Windows fails to compile the regex feature check under C++11
+  set(EXTRA_CXX_FLAGS "-DCMAKE_CXX_STANDARD=14")
+endif()
+
+# C++ feature checks Determine the correct regular expression engine to use
+cxx_feature_check(STD_REGEX ${EXTRA_CXX_FLAGS})
+cxx_feature_check(GNU_POSIX_REGEX ${EXTRA_CXX_FLAGS})
+cxx_feature_check(POSIX_REGEX ${EXTRA_CXX_FLAGS})
+if(NOT HAVE_STD_REGEX
+   AND NOT HAVE_GNU_POSIX_REGEX
+   AND NOT HAVE_POSIX_REGEX)
+  message(
+    FATAL_ERROR
+      "Failed to determine the source files for the regular expression backend")
+endif()
+if(NOT BENCHMARK_ENABLE_EXCEPTIONS
+   AND HAVE_STD_REGEX
+   AND NOT HAVE_GNU_POSIX_REGEX
+   AND NOT HAVE_POSIX_REGEX)
+  message(
+    WARNING "Using std::regex with exceptions disabled is not fully supported")
+endif()
+
+cxx_feature_check(STEADY_CLOCK)
+# Ensure we have pthreads
+set(THREADS_PREFER_PTHREAD_FLAG ON)
+find_package(Threads REQUIRED)
+cxx_feature_check(PTHREAD_AFFINITY)
+
+if(BENCHMARK_ENABLE_LIBPFM)
+  find_package(PFM REQUIRED)
+endif()
+
+# Set up directories
+include_directories(${PROJECT_SOURCE_DIR}/include)
+
+# Build the targets
+add_subdirectory(src)
+
+if(BENCHMARK_ENABLE_TESTING)
+  enable_testing()
+  if(BENCHMARK_ENABLE_GTEST_TESTS
+     AND NOT
+         (TARGET gtest
+          AND TARGET gtest_main
+          AND TARGET gmock
+          AND TARGET gmock_main))
+    if(BENCHMARK_USE_BUNDLED_GTEST)
+      include(GoogleTest)
+    else()
+      find_package(GTest CONFIG REQUIRED)
+      add_library(gtest ALIAS GTest::gtest)
+      add_library(gtest_main ALIAS GTest::gtest_main)
+      add_library(gmock ALIAS GTest::gmock)
+      add_library(gmock_main ALIAS GTest::gmock_main)
+    endif()
+  endif()
+  add_subdirectory(test)
+endif()

third_party/benchmark/CONTRIBUTING.md

@@ -0,0 +1,58 @@
+# How to contribute #
+
+We'd love to accept your patches and contributions to this project.  There are
+a just a few small guidelines you need to follow.
+
+
+## Contributor License Agreement ##
+
+Contributions to any Google project must be accompanied by a Contributor
+License Agreement.  This is not a copyright **assignment**, it simply gives
+Google permission to use and redistribute your contributions as part of the
+project.
+
+  * If you are an individual writing original source code and you're sure you
+    own the intellectual property, then you'll need to sign an [individual
+    CLA][].
+
+  * If you work for a company that wants to allow you to contribute your work,
+    then you'll need to sign a [corporate CLA][].
+
+You generally only need to submit a CLA once, so if you've already submitted
+one (even if it was for a different project), you probably don't need to do it
+again.
+
+[individual CLA]: https://developers.google.com/open-source/cla/individual
+[corporate CLA]: https://developers.google.com/open-source/cla/corporate
+
+Once your CLA is submitted (or if you already submitted one for
+another Google project), make a commit adding yourself to the
+[AUTHORS][] and [CONTRIBUTORS][] files. This commit can be part
+of your first [pull request][].
+
+[AUTHORS]: AUTHORS
+[CONTRIBUTORS]: CONTRIBUTORS
+
+
+## Submitting a patch ##
+
+  1. It's generally best to start by opening a new issue describing the bug or
+     feature you're intending to fix.  Even if you think it's relatively minor,
+     it's helpful to know what people are working on.  Mention in the initial
+     issue that you are planning to work on that bug or feature so that it can
+     be assigned to you.
+
+  1. Follow the normal process of [forking][] the project, and setup a new
+     branch to work in.  It's important that each group of changes be done in
+     separate branches in order to ensure that a pull request only includes the
+     commits related to that bug or feature.
+
+  1. Do your best to have [well-formed commit messages][] for each change.
+     This provides consistency throughout the project, and ensures that commit
+     messages are able to be formatted properly by various git tools.
+
+  1. Finally, push the commits to your fork and submit a [pull request][].
+
+[forking]: https://help.github.com/articles/fork-a-repo
+[well-formed commit messages]: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
+[pull request]: https://help.github.com/articles/creating-a-pull-request

third_party/benchmark/CONTRIBUTORS

@@ -0,0 +1,97 @@
+# People who have agreed to one of the CLAs and can contribute patches.
+# The AUTHORS file lists the copyright holders; this file
+# lists people.  For example, Google employees are listed here
+# but not in AUTHORS, because Google holds the copyright.
+#
+# Names should be added to this file only after verifying that
+# the individual or the individual's organization has agreed to
+# the appropriate Contributor License Agreement, found here:
+#
+# https://developers.google.com/open-source/cla/individual
+# https://developers.google.com/open-source/cla/corporate
+#
+# The agreement for individuals can be filled out on the web.
+#
+# When adding J Random Contributor's name to this file,
+# either J's name or J's organization's name should be
+# added to the AUTHORS file, depending on whether the
+# individual or corporate CLA was used.
+#
+# Names should be added to this file as:
+#     Name <email address>
+#
+# Please keep the list sorted.
+
+Abhina Sreeskantharajan <abhina.sreeskantharajan@ibm.com>
+Albert Pretorius <pretoalb@gmail.com>
+Alex Steele <steelal123@gmail.com>
+Andriy Berestovskyy <berestovskyy@gmail.com>
+Arne Beer <arne@twobeer.de>
+Bátor Tallér <bator.taller@shapr3d.com>
+Billy Robert O'Neal III <billy.oneal@gmail.com> <bion@microsoft.com>
+Cezary Skrzyński <czars1988@gmail.com>
+Chris Kennelly <ckennelly@google.com> <ckennelly@ckennelly.com>
+Christian Wassermann <christian_wassermann@web.de>
+Christopher Seymour <chris.j.seymour@hotmail.com>
+Colin Braley <braley.colin@gmail.com>
+Cyrille Faucheux <cyrille.faucheux@gmail.com>
+Daniel Harvey <danielharvey458@gmail.com>
+David Coeurjolly <david.coeurjolly@liris.cnrs.fr>
+Deniz Evrenci <denizevrenci@gmail.com>
+Dominic Hamon <dma@stripysock.com> <dominic@google.com>
+Dominik Czarnota <dominik.b.czarnota@gmail.com>
+Dominik Korman <kormandominik@gmail.com>
+Donald Aingworth <donalds_junk_mail@yahoo.com>
+Eric Backus <eric_backus@alum.mit.edu>
+Eric Fiselier <eric@efcs.ca>
+Eugene Zhuk <eugene.zhuk@gmail.com>
+Evgeny Safronov <division494@gmail.com>
+Fabien Pichot <pichot.fabien@gmail.com>
+Fanbo Meng <fanbo.meng@ibm.com>
+Federico Ficarelli <federico.ficarelli@gmail.com>
+Felix Homann <linuxaudio@showlabor.de>
+Geoffrey Martin-Noble <gcmn@google.com> <gmngeoffrey@gmail.com>
+Gergely Meszaros <maetveis@gmail.com>
+Gergő Szitár <szitar.gergo@gmail.com>
+Hannes Hauswedell <h2@fsfe.org>
+Henrique Bucher <hbucher@gmail.com>
+Ismael Jimenez Martinez <ismael.jimenez.martinez@gmail.com>
+Iakov Sergeev <yahontu@gmail.com>
+Jern-Kuan Leong <jernkuan@gmail.com>
+JianXiong Zhou <zhoujianxiong2@gmail.com>
+Joao Paulo Magalhaes <joaoppmagalhaes@gmail.com>
+John Millikin <jmillikin@stripe.com>
+Jordan Williams <jwillikers@protonmail.com>
+Jussi Knuuttila <jussi.knuuttila@gmail.com>
+Kaito Udagawa <umireon@gmail.com>
+Kai Wolf <kai.wolf@gmail.com>
+Kishan Kumar <kumar.kishan@outlook.com>
+Lei Xu <eddyxu@gmail.com>
+Marcel Jacobse <mjacobse@uni-bremen.de>
+Matt Clarkson <mattyclarkson@gmail.com>
+Maxim Vafin <maxvafin@gmail.com>
+Mike Apodaca <gatorfax@gmail.com>
+Min-Yih Hsu <yihshyng223@gmail.com>
+Nick Hutchinson <nshutchinson@gmail.com>
+Norman Heino <norman.heino@gmail.com>
+Oleksandr Sochka <sasha.sochka@gmail.com>
+Ori Livneh <ori.livneh@gmail.com>
+Pascal Leroy <phl@google.com>
+Paul Redmond <paul.redmond@gmail.com>
+Pierre Phaneuf <pphaneuf@google.com>
+Radoslav Yovchev <radoslav.tm@gmail.com>
+Raghu Raja <raghu@enfabrica.net>
+Rainer Orth <ro@cebitec.uni-bielefeld.de>
+Raul Marin <rmrodriguez@cartodb.com>
+Ray Glover <ray.glover@uk.ibm.com>
+Robert Guo <robert.guo@mongodb.com>
+Roman Lebedev <lebedev.ri@gmail.com>
+Sayan Bhattacharjee <aero.sayan@gmail.com>
+Shuo Chen <chenshuo@chenshuo.com>
+Steven Wan <wan.yu@ibm.com>
+Tobias Schmidt <tobias.schmidt@in.tum.de>
+Tobias Ulvgård <tobias.ulvgard@dirac.se>
+Tom Madams <tom.ej.madams@gmail.com> <tmadams@google.com>
+Yixuan Qiu <yixuanq@gmail.com>
+Yusuke Suzuki <utatane.tea@gmail.com>
+Zbigniew Skowron <zbychs@gmail.com>

third_party/benchmark/LICENSE

@@ -0,0 +1,202 @@
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third_party/benchmark/MODULE.bazel

@@ -0,0 +1,41 @@
+module(
+    name = "google_benchmark",
+    version = "1.8.4",
+)
+
+bazel_dep(name = "bazel_skylib", version = "1.5.0")
+bazel_dep(name = "platforms", version = "0.0.8")
+bazel_dep(name = "rules_foreign_cc", version = "0.10.1")
+bazel_dep(name = "rules_cc", version = "0.0.9")
+
+bazel_dep(name = "rules_python", version = "0.31.0", dev_dependency = True)
+bazel_dep(name = "googletest", version = "1.12.1", dev_dependency = True, repo_name = "com_google_googletest")
+
+bazel_dep(name = "libpfm", version = "4.11.0")
+
+# Register a toolchain for Python 3.9 to be able to build numpy. Python
+# versions >=3.10 are problematic.
+# A second reason for this is to be able to build Python hermetically instead
+# of relying on the changing default version from rules_python.
+
+python = use_extension("@rules_python//python/extensions:python.bzl", "python", dev_dependency = True)
+python.toolchain(python_version = "3.8")
+python.toolchain(python_version = "3.9")
+python.toolchain(python_version = "3.10")
+python.toolchain(python_version = "3.11")
+python.toolchain(
+    is_default = True,
+    python_version = "3.12",
+)
+
+pip = use_extension("@rules_python//python/extensions:pip.bzl", "pip", dev_dependency = True)
+pip.parse(
+    hub_name = "tools_pip_deps",
+    python_version = "3.9",
+    requirements_lock = "//tools:requirements.txt",
+)
+use_repo(pip, "tools_pip_deps")
+
+# -- bazel_dep definitions -- #
+
+bazel_dep(name = "nanobind_bazel", version = "1.0.0", dev_dependency = True)

third_party/benchmark/README.md

@@ -0,0 +1,223 @@
+# Benchmark
+
+[![build-and-test](https://github.com/google/benchmark/workflows/build-and-test/badge.svg)](https://github.com/google/benchmark/actions?query=workflow%3Abuild-and-test)
+[![bazel](https://github.com/google/benchmark/actions/workflows/bazel.yml/badge.svg)](https://github.com/google/benchmark/actions/workflows/bazel.yml)
+[![pylint](https://github.com/google/benchmark/workflows/pylint/badge.svg)](https://github.com/google/benchmark/actions?query=workflow%3Apylint)
+[![test-bindings](https://github.com/google/benchmark/workflows/test-bindings/badge.svg)](https://github.com/google/benchmark/actions?query=workflow%3Atest-bindings)
+[![Coverage Status](https://coveralls.io/repos/google/benchmark/badge.svg)](https://coveralls.io/r/google/benchmark)
+
+[![Discord](https://discordapp.com/api/guilds/1125694995928719494/widget.png?style=shield)](https://discord.gg/cz7UX7wKC2)
+
+A library to benchmark code snippets, similar to unit tests. Example:
+
+```c++
+#include <benchmark/benchmark.h>
+
+static void BM_SomeFunction(benchmark::State& state) {
+  // Perform setup here
+  for (auto _ : state) {
+    // This code gets timed
+    SomeFunction();
+  }
+}
+// Register the function as a benchmark
+BENCHMARK(BM_SomeFunction);
+// Run the benchmark
+BENCHMARK_MAIN();
+```
+
+## Getting Started
+
+To get started, see [Requirements](#requirements) and
+[Installation](#installation). See [Usage](#usage) for a full example and the
+[User Guide](docs/user_guide.md) for a more comprehensive feature overview.
+
+It may also help to read the [Google Test documentation](https://github.com/google/googletest/blob/main/docs/primer.md)
+as some of the structural aspects of the APIs are similar.
+
+## Resources
+
+[Discussion group](https://groups.google.com/d/forum/benchmark-discuss)
+
+IRC channels:
+* [libera](https://libera.chat) #benchmark
+
+[Additional Tooling Documentation](docs/tools.md)
+
+[Assembly Testing Documentation](docs/AssemblyTests.md)
+
+[Building and installing Python bindings](docs/python_bindings.md)
+
+## Requirements
+
+The library can be used with C++03. However, it requires C++11 to build,
+including compiler and standard library support.
+
+The following minimum versions are required to build the library:
+
+* GCC 4.8
+* Clang 3.4
+* Visual Studio 14 2015
+* Intel 2015 Update 1
+
+See [Platform-Specific Build Instructions](docs/platform_specific_build_instructions.md).
+
+## Installation
+
+This describes the installation process using cmake. As pre-requisites, you'll
+need git and cmake installed.
+
+_See [dependencies.md](docs/dependencies.md) for more details regarding supported
+versions of build tools._
+
+```bash
+# Check out the library.
+$ git clone https://github.com/google/benchmark.git
+# Go to the library root directory
+$ cd benchmark
+# Make a build directory to place the build output.
+$ cmake -E make_directory "build"
+# Generate build system files with cmake, and download any dependencies.
+$ cmake -E chdir "build" cmake -DBENCHMARK_DOWNLOAD_DEPENDENCIES=on -DCMAKE_BUILD_TYPE=Release ../
+# or, starting with CMake 3.13, use a simpler form:
+# cmake -DCMAKE_BUILD_TYPE=Release -S . -B "build"
+# Build the library.
+$ cmake --build "build" --config Release
+```
+This builds the `benchmark` and `benchmark_main` libraries and tests.
+On a unix system, the build directory should now look something like this:
+
+```
+/benchmark
+  /build
+    /src
+      /libbenchmark.a
+      /libbenchmark_main.a
+    /test
+      ...
+```
+
+Next, you can run the tests to check the build.
+
+```bash
+$ cmake -E chdir "build" ctest --build-config Release
+```
+
+If you want to install the library globally, also run:
+
+```
+sudo cmake --build "build" --config Release --target install
+```
+
+Note that Google Benchmark requires Google Test to build and run the tests. This
+dependency can be provided two ways:
+
+* Checkout the Google Test sources into `benchmark/googletest`.
+* Otherwise, if `-DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON` is specified during
+  configuration as above, the library will automatically download and build
+  any required dependencies.
+
+If you do not wish to build and run the tests, add `-DBENCHMARK_ENABLE_GTEST_TESTS=OFF`
+to `CMAKE_ARGS`.
+
+### Debug vs Release
+
+By default, benchmark builds as a debug library. You will see a warning in the
+output when this is the case. To build it as a release library instead, add
+`-DCMAKE_BUILD_TYPE=Release` when generating the build system files, as shown
+above. The use of `--config Release` in build commands is needed to properly
+support multi-configuration tools (like Visual Studio for example) and can be
+skipped for other build systems (like Makefile).
+
+To enable link-time optimisation, also add `-DBENCHMARK_ENABLE_LTO=true` when
+generating the build system files.
+
+If you are using gcc, you might need to set `GCC_AR` and `GCC_RANLIB` cmake
+cache variables, if autodetection fails.
+
+If you are using clang, you may need to set `LLVMAR_EXECUTABLE`,
+`LLVMNM_EXECUTABLE` and `LLVMRANLIB_EXECUTABLE` cmake cache variables.
+
+To enable sanitizer checks (eg., `asan` and `tsan`), add:
+```
+ -DCMAKE_C_FLAGS="-g -O2 -fno-omit-frame-pointer -fsanitize=address -fsanitize=thread -fno-sanitize-recover=all"
+ -DCMAKE_CXX_FLAGS="-g -O2 -fno-omit-frame-pointer -fsanitize=address -fsanitize=thread -fno-sanitize-recover=all "  
+```
+
+### Stable and Experimental Library Versions
+
+The main branch contains the latest stable version of the benchmarking library;
+the API of which can be considered largely stable, with source breaking changes
+being made only upon the release of a new major version.
+
+Newer, experimental, features are implemented and tested on the
+[`v2` branch](https://github.com/google/benchmark/tree/v2). Users who wish
+to use, test, and provide feedback on the new features are encouraged to try
+this branch. However, this branch provides no stability guarantees and reserves
+the right to change and break the API at any time.
+
+## Usage
+
+### Basic usage
+
+Define a function that executes the code to measure, register it as a benchmark
+function using the `BENCHMARK` macro, and ensure an appropriate `main` function
+is available:
+
+```c++
+#include <benchmark/benchmark.h>
+
+static void BM_StringCreation(benchmark::State& state) {
+  for (auto _ : state)
+    std::string empty_string;
+}
+// Register the function as a benchmark
+BENCHMARK(BM_StringCreation);
+
+// Define another benchmark
+static void BM_StringCopy(benchmark::State& state) {
+  std::string x = "hello";
+  for (auto _ : state)
+    std::string copy(x);
+}
+BENCHMARK(BM_StringCopy);
+
+BENCHMARK_MAIN();
+```
+
+To run the benchmark, compile and link against the `benchmark` library
+(libbenchmark.a/.so). If you followed the build steps above, this library will 
+be under the build directory you created.
+
+```bash
+# Example on linux after running the build steps above. Assumes the
+# `benchmark` and `build` directories are under the current directory.
+$ g++ mybenchmark.cc -std=c++11 -isystem benchmark/include \
+  -Lbenchmark/build/src -lbenchmark -lpthread -o mybenchmark
+```
+
+Alternatively, link against the `benchmark_main` library and remove
+`BENCHMARK_MAIN();` above to get the same behavior.
+
+The compiled executable will run all benchmarks by default. Pass the `--help`
+flag for option information or see the [User Guide](docs/user_guide.md).
+
+### Usage with CMake
+
+If using CMake, it is recommended to link against the project-provided
+`benchmark::benchmark` and `benchmark::benchmark_main` targets using
+`target_link_libraries`.
+It is possible to use ```find_package``` to import an installed version of the
+library.
+```cmake
+find_package(benchmark REQUIRED)
+```
+Alternatively, ```add_subdirectory``` will incorporate the library directly in
+to one's CMake project.
+```cmake
+add_subdirectory(benchmark)
+```
+Either way, link to the library as follows.
+```cmake
+target_link_libraries(MyTarget benchmark::benchmark)
+```

third_party/benchmark/WORKSPACE

@@ -0,0 +1,24 @@
+workspace(name = "com_github_google_benchmark")
+
+load("//:bazel/benchmark_deps.bzl", "benchmark_deps")
+
+benchmark_deps()
+
+load("@rules_foreign_cc//foreign_cc:repositories.bzl", "rules_foreign_cc_dependencies")
+
+rules_foreign_cc_dependencies()
+
+load("@rules_python//python:repositories.bzl", "py_repositories")
+
+py_repositories()
+
+load("@rules_python//python:pip.bzl", "pip_parse")
+
+pip_parse(
+    name = "tools_pip_deps",
+    requirements_lock = "//tools:requirements.txt",
+)
+
+load("@tools_pip_deps//:requirements.bzl", "install_deps")
+
+install_deps()

third_party/benchmark/WORKSPACE.bzlmod

@@ -0,0 +1,2 @@
+# This file marks the root of the Bazel workspace.
+# See MODULE.bazel for dependencies and setup.

third_party/benchmark/_config.yml

@@ -0,0 +1,2 @@
+theme: jekyll-theme-midnight
+markdown: GFM

third_party/benchmark/appveyor.yml

@@ -0,0 +1,50 @@
+version: '{build}'
+
+image: Visual Studio 2017
+
+configuration:
+  - Debug
+  - Release
+
+environment:
+  matrix:
+    - compiler: msvc-15-seh
+      generator: "Visual Studio 15 2017"
+
+    - compiler: msvc-15-seh
+      generator: "Visual Studio 15 2017 Win64"
+
+    - compiler: msvc-14-seh
+      generator: "Visual Studio 14 2015"
+
+    - compiler: msvc-14-seh
+      generator: "Visual Studio 14 2015 Win64"
+
+    - compiler: gcc-5.3.0-posix
+      generator: "MinGW Makefiles"
+      cxx_path: 'C:\mingw-w64\i686-5.3.0-posix-dwarf-rt_v4-rev0\mingw32\bin'
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+
+matrix:
+  fast_finish: true
+
+install:
+  # git bash conflicts with MinGW makefiles
+  - if "%generator%"=="MinGW Makefiles" (set "PATH=%PATH:C:\Program Files\Git\usr\bin;=%")
+  - if not "%cxx_path%"=="" (set "PATH=%PATH%;%cxx_path%")
+
+build_script:
+  - md _build -Force
+  - cd _build
+  - echo %configuration%
+  - cmake -G "%generator%" "-DCMAKE_BUILD_TYPE=%configuration%" -DBENCHMARK_DOWNLOAD_DEPENDENCIES=ON ..
+  - cmake --build . --config %configuration%
+
+test_script:
+  - ctest --build-config %configuration% --timeout 300 --output-on-failure
+
+artifacts:
+  - path: '_build/CMakeFiles/*.log'
+    name: logs
+  - path: '_build/Testing/**/*.xml'
+    name: test_results

third_party/benchmark/bazel/benchmark_deps.bzl

@@ -0,0 +1,62 @@
+"""
+This file contains the Bazel build dependencies for Google Benchmark (both C++ source and Python bindings).
+"""
+
+load("@bazel_tools//tools/build_defs/repo:git.bzl", "new_git_repository")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+def benchmark_deps():
+    """Loads dependencies required to build Google Benchmark."""
+
+    if "bazel_skylib" not in native.existing_rules():
+        http_archive(
+            name = "bazel_skylib",
+            sha256 = "cd55a062e763b9349921f0f5db8c3933288dc8ba4f76dd9416aac68acee3cb94",
+            urls = [
+                "https://mirror.bazel.build/github.com/bazelbuild/bazel-skylib/releases/download/1.5.0/bazel-skylib-1.5.0.tar.gz",
+                "https://github.com/bazelbuild/bazel-skylib/releases/download/1.5.0/bazel-skylib-1.5.0.tar.gz",
+            ],
+        )
+
+    if "rules_foreign_cc" not in native.existing_rules():
+        http_archive(
+            name = "rules_foreign_cc",
+            sha256 = "476303bd0f1b04cc311fc258f1708a5f6ef82d3091e53fd1977fa20383425a6a",
+            strip_prefix = "rules_foreign_cc-0.10.1",
+            url = "https://github.com/bazelbuild/rules_foreign_cc/releases/download/0.10.1/rules_foreign_cc-0.10.1.tar.gz",
+        )
+
+    if "rules_python" not in native.existing_rules():
+        http_archive(
+            name = "rules_python",
+            sha256 = "e85ae30de33625a63eca7fc40a94fea845e641888e52f32b6beea91e8b1b2793",
+            strip_prefix = "rules_python-0.27.1",
+            url = "https://github.com/bazelbuild/rules_python/releases/download/0.27.1/rules_python-0.27.1.tar.gz",
+        )
+
+    if "com_google_googletest" not in native.existing_rules():
+        new_git_repository(
+            name = "com_google_googletest",
+            remote = "https://github.com/google/googletest.git",
+            tag = "release-1.12.1",
+        )
+
+    if "nanobind" not in native.existing_rules():
+        new_git_repository(
+            name = "nanobind",
+            remote = "https://github.com/wjakob/nanobind.git",
+            tag = "v1.8.0",
+            build_file = "@//bindings/python:nanobind.BUILD",
+            recursive_init_submodules = True,
+        )
+
+    if "libpfm" not in native.existing_rules():
+        # Downloaded from v4.9.0 tag at https://sourceforge.net/p/perfmon2/libpfm4/ref/master/tags/
+        http_archive(
+            name = "libpfm",
+            build_file = str(Label("//tools:libpfm.BUILD.bazel")),
+            sha256 = "5da5f8872bde14b3634c9688d980f68bda28b510268723cc12973eedbab9fecc",
+            type = "tar.gz",
+            strip_prefix = "libpfm-4.11.0",
+            urls = ["https://sourceforge.net/projects/perfmon2/files/libpfm4/libpfm-4.11.0.tar.gz/download"],
+        )

third_party/benchmark/bindings/python/google_benchmark/BUILD

@@ -0,0 +1,27 @@
+load("@nanobind_bazel//:build_defs.bzl", "nanobind_extension")
+
+py_library(
+    name = "google_benchmark",
+    srcs = ["__init__.py"],
+    visibility = ["//visibility:public"],
+    deps = [
+        ":_benchmark",
+    ],
+)
+
+nanobind_extension(
+    name = "_benchmark",
+    srcs = ["benchmark.cc"],
+    deps = ["//:benchmark"],
+)
+
+py_test(
+    name = "example",
+    srcs = ["example.py"],
+    python_version = "PY3",
+    srcs_version = "PY3",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":google_benchmark",
+    ],
+)

third_party/benchmark/bindings/python/google_benchmark/__init__.py

@@ -0,0 +1,141 @@
+# Copyright 2020 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Python benchmarking utilities.
+
+Example usage:
+  import google_benchmark as benchmark
+
+  @benchmark.register
+  def my_benchmark(state):
+      ...  # Code executed outside `while` loop is not timed.
+
+      while state:
+        ...  # Code executed within `while` loop is timed.
+
+  if __name__ == '__main__':
+    benchmark.main()
+"""
+
+import atexit
+
+from absl import app
+
+from google_benchmark import _benchmark
+from google_benchmark._benchmark import (
+    Counter as Counter,
+    State as State,
+    kMicrosecond as kMicrosecond,
+    kMillisecond as kMillisecond,
+    kNanosecond as kNanosecond,
+    kSecond as kSecond,
+    o1 as o1,
+    oAuto as oAuto,
+    oLambda as oLambda,
+    oLogN as oLogN,
+    oN as oN,
+    oNCubed as oNCubed,
+    oNLogN as oNLogN,
+    oNone as oNone,
+    oNSquared as oNSquared,
+)
+from google_benchmark.version import __version__ as __version__
+
+
+class __OptionMaker:
+    """A stateless class to collect benchmark options.
+
+    Collect all decorator calls like @option.range(start=0, limit=1<<5).
+    """
+
+    class Options:
+        """Pure data class to store options calls, along with the benchmarked function."""
+
+        def __init__(self, func):
+            self.func = func
+            self.builder_calls = []
+
+    @classmethod
+    def make(cls, func_or_options):
+        """Make Options from Options or the benchmarked function."""
+        if isinstance(func_or_options, cls.Options):
+            return func_or_options
+        return cls.Options(func_or_options)
+
+    def __getattr__(self, builder_name):
+        """Append option call in the Options."""
+
+        # The function that get returned on @option.range(start=0, limit=1<<5).
+        def __builder_method(*args, **kwargs):
+            # The decorator that get called, either with the benchmared function
+            # or the previous Options
+            def __decorator(func_or_options):
+                options = self.make(func_or_options)
+                options.builder_calls.append((builder_name, args, kwargs))
+                # The decorator returns Options so it is not technically a decorator
+                # and needs a final call to @register
+                return options
+
+            return __decorator
+
+        return __builder_method
+
+
+# Alias for nicer API.
+# We have to instantiate an object, even if stateless, to be able to use __getattr__
+# on option.range
+option = __OptionMaker()
+
+
+def register(undefined=None, *, name=None):
+    """Register function for benchmarking."""
+    if undefined is None:
+        # Decorator is called without parenthesis so we return a decorator
+        return lambda f: register(f, name=name)
+
+    # We have either the function to benchmark (simple case) or an instance of Options
+    # (@option._ case).
+    options = __OptionMaker.make(undefined)
+
+    if name is None:
+        name = options.func.__name__
+
+    # We register the benchmark and reproduce all the @option._ calls onto the
+    # benchmark builder pattern
+    benchmark = _benchmark.RegisterBenchmark(name, options.func)
+    for name, args, kwargs in options.builder_calls[::-1]:
+        getattr(benchmark, name)(*args, **kwargs)
+
+    # return the benchmarked function because the decorator does not modify it
+    return options.func
+
+
+def _flags_parser(argv):
+    argv = _benchmark.Initialize(argv)
+    return app.parse_flags_with_usage(argv)
+
+
+def _run_benchmarks(argv):
+    if len(argv) > 1:
+        raise app.UsageError("Too many command-line arguments.")
+    return _benchmark.RunSpecifiedBenchmarks()
+
+
+def main(argv=None):
+    return app.run(_run_benchmarks, argv=argv, flags_parser=_flags_parser)
+
+
+# Methods for use with custom main function.
+initialize = _benchmark.Initialize
+run_benchmarks = _benchmark.RunSpecifiedBenchmarks
+atexit.register(_benchmark.ClearRegisteredBenchmarks)

third_party/benchmark/bindings/python/google_benchmark/benchmark.cc

@@ -0,0 +1,184 @@
+// Benchmark for Python.
+
+#include "benchmark/benchmark.h"
+
+#include "nanobind/nanobind.h"
+#include "nanobind/operators.h"
+#include "nanobind/stl/bind_map.h"
+#include "nanobind/stl/string.h"
+#include "nanobind/stl/vector.h"
+
+NB_MAKE_OPAQUE(benchmark::UserCounters);
+
+namespace {
+namespace nb = nanobind;
+
+std::vector<std::string> Initialize(const std::vector<std::string>& argv) {
+  // The `argv` pointers here become invalid when this function returns, but
+  // benchmark holds the pointer to `argv[0]`. We create a static copy of it
+  // so it persists, and replace the pointer below.
+  static std::string executable_name(argv[0]);
+  std::vector<char*> ptrs;
+  ptrs.reserve(argv.size());
+  for (auto& arg : argv) {
+    ptrs.push_back(const_cast<char*>(arg.c_str()));
+  }
+  ptrs[0] = const_cast<char*>(executable_name.c_str());
+  int argc = static_cast<int>(argv.size());
+  benchmark::Initialize(&argc, ptrs.data());
+  std::vector<std::string> remaining_argv;
+  remaining_argv.reserve(argc);
+  for (int i = 0; i < argc; ++i) {
+    remaining_argv.emplace_back(ptrs[i]);
+  }
+  return remaining_argv;
+}
+
+benchmark::internal::Benchmark* RegisterBenchmark(const std::string& name,
+                                                  nb::callable f) {
+  return benchmark::RegisterBenchmark(
+      name, [f](benchmark::State& state) { f(&state); });
+}
+
+NB_MODULE(_benchmark, m) {
+
+  using benchmark::TimeUnit;
+  nb::enum_<TimeUnit>(m, "TimeUnit")
+      .value("kNanosecond", TimeUnit::kNanosecond)
+      .value("kMicrosecond", TimeUnit::kMicrosecond)
+      .value("kMillisecond", TimeUnit::kMillisecond)
+      .value("kSecond", TimeUnit::kSecond)
+      .export_values();
+
+  using benchmark::BigO;
+  nb::enum_<BigO>(m, "BigO")
+      .value("oNone", BigO::oNone)
+      .value("o1", BigO::o1)
+      .value("oN", BigO::oN)
+      .value("oNSquared", BigO::oNSquared)
+      .value("oNCubed", BigO::oNCubed)
+      .value("oLogN", BigO::oLogN)
+      .value("oNLogN", BigO::oNLogN)
+      .value("oAuto", BigO::oAuto)
+      .value("oLambda", BigO::oLambda)
+      .export_values();
+
+  using benchmark::internal::Benchmark;
+  nb::class_<Benchmark>(m, "Benchmark")
+      // For methods returning a pointer to the current object, reference
+      // return policy is used to ask nanobind not to take ownership of the
+      // returned object and avoid calling delete on it.
+      // https://pybind11.readthedocs.io/en/stable/advanced/functions.html#return-value-policies
+      //
+      // For methods taking a const std::vector<...>&, a copy is created
+      // because a it is bound to a Python list.
+      // https://pybind11.readthedocs.io/en/stable/advanced/cast/stl.html
+      .def("unit", &Benchmark::Unit, nb::rv_policy::reference)
+      .def("arg", &Benchmark::Arg, nb::rv_policy::reference)
+      .def("args", &Benchmark::Args, nb::rv_policy::reference)
+      .def("range", &Benchmark::Range, nb::rv_policy::reference,
+           nb::arg("start"), nb::arg("limit"))
+      .def("dense_range", &Benchmark::DenseRange,
+           nb::rv_policy::reference, nb::arg("start"),
+           nb::arg("limit"), nb::arg("step") = 1)
+      .def("ranges", &Benchmark::Ranges, nb::rv_policy::reference)
+      .def("args_product", &Benchmark::ArgsProduct,
+           nb::rv_policy::reference)
+      .def("arg_name", &Benchmark::ArgName, nb::rv_policy::reference)
+      .def("arg_names", &Benchmark::ArgNames,
+           nb::rv_policy::reference)
+      .def("range_pair", &Benchmark::RangePair,
+           nb::rv_policy::reference, nb::arg("lo1"), nb::arg("hi1"),
+           nb::arg("lo2"), nb::arg("hi2"))
+      .def("range_multiplier", &Benchmark::RangeMultiplier,
+           nb::rv_policy::reference)
+      .def("min_time", &Benchmark::MinTime, nb::rv_policy::reference)
+      .def("min_warmup_time", &Benchmark::MinWarmUpTime,
+           nb::rv_policy::reference)
+      .def("iterations", &Benchmark::Iterations,
+           nb::rv_policy::reference)
+      .def("repetitions", &Benchmark::Repetitions,
+           nb::rv_policy::reference)
+      .def("report_aggregates_only", &Benchmark::ReportAggregatesOnly,
+           nb::rv_policy::reference, nb::arg("value") = true)
+      .def("display_aggregates_only", &Benchmark::DisplayAggregatesOnly,
+           nb::rv_policy::reference, nb::arg("value") = true)
+      .def("measure_process_cpu_time", &Benchmark::MeasureProcessCPUTime,
+           nb::rv_policy::reference)
+      .def("use_real_time", &Benchmark::UseRealTime,
+           nb::rv_policy::reference)
+      .def("use_manual_time", &Benchmark::UseManualTime,
+           nb::rv_policy::reference)
+      .def(
+          "complexity",
+          (Benchmark * (Benchmark::*)(benchmark::BigO)) & Benchmark::Complexity,
+          nb::rv_policy::reference,
+          nb::arg("complexity") = benchmark::oAuto);
+
+  using benchmark::Counter;
+  nb::class_<Counter> py_counter(m, "Counter");
+
+  nb::enum_<Counter::Flags>(py_counter, "Flags")
+      .value("kDefaults", Counter::Flags::kDefaults)
+      .value("kIsRate", Counter::Flags::kIsRate)
+      .value("kAvgThreads", Counter::Flags::kAvgThreads)
+      .value("kAvgThreadsRate", Counter::Flags::kAvgThreadsRate)
+      .value("kIsIterationInvariant", Counter::Flags::kIsIterationInvariant)
+      .value("kIsIterationInvariantRate",
+             Counter::Flags::kIsIterationInvariantRate)
+      .value("kAvgIterations", Counter::Flags::kAvgIterations)
+      .value("kAvgIterationsRate", Counter::Flags::kAvgIterationsRate)
+      .value("kInvert", Counter::Flags::kInvert)
+      .export_values()
+      .def(nb::self | nb::self);
+
+  nb::enum_<Counter::OneK>(py_counter, "OneK")
+      .value("kIs1000", Counter::OneK::kIs1000)
+      .value("kIs1024", Counter::OneK::kIs1024)
+      .export_values();
+
+  py_counter
+      .def(nb::init<double, Counter::Flags, Counter::OneK>(),
+           nb::arg("value") = 0., nb::arg("flags") = Counter::kDefaults,
+           nb::arg("k") = Counter::kIs1000)
+      .def("__init__", ([](Counter *c, double value) { new (c) Counter(value); }))
+      .def_rw("value", &Counter::value)
+      .def_rw("flags", &Counter::flags)
+      .def_rw("oneK", &Counter::oneK)
+      .def(nb::init_implicit<double>());
+
+  nb::implicitly_convertible<nb::int_, Counter>();
+
+  nb::bind_map<benchmark::UserCounters>(m, "UserCounters");
+
+  using benchmark::State;
+  nb::class_<State>(m, "State")
+      .def("__bool__", &State::KeepRunning)
+      .def_prop_ro("keep_running", &State::KeepRunning)
+      .def("pause_timing", &State::PauseTiming)
+      .def("resume_timing", &State::ResumeTiming)
+      .def("skip_with_error", &State::SkipWithError)
+      .def_prop_ro("error_occurred", &State::error_occurred)
+      .def("set_iteration_time", &State::SetIterationTime)
+      .def_prop_rw("bytes_processed", &State::bytes_processed,
+                    &State::SetBytesProcessed)
+      .def_prop_rw("complexity_n", &State::complexity_length_n,
+                    &State::SetComplexityN)
+      .def_prop_rw("items_processed", &State::items_processed,
+                   &State::SetItemsProcessed)
+      .def("set_label", &State::SetLabel)
+      .def("range", &State::range, nb::arg("pos") = 0)
+      .def_prop_ro("iterations", &State::iterations)
+      .def_prop_ro("name", &State::name)
+      .def_rw("counters", &State::counters)
+      .def_prop_ro("thread_index", &State::thread_index)
+      .def_prop_ro("threads", &State::threads);
+
+  m.def("Initialize", Initialize);
+  m.def("RegisterBenchmark", RegisterBenchmark,
+        nb::rv_policy::reference);
+  m.def("RunSpecifiedBenchmarks",
+        []() { benchmark::RunSpecifiedBenchmarks(); });
+  m.def("ClearRegisteredBenchmarks", benchmark::ClearRegisteredBenchmarks);
+};
+}  // namespace

third_party/benchmark/bindings/python/google_benchmark/example.py

@@ -0,0 +1,139 @@
+# Copyright 2020 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Example of Python using C++ benchmark framework.
+
+To run this example, you must first install the `google_benchmark` Python package.
+
+To install using `setup.py`, download and extract the `google_benchmark` source.
+In the extracted directory, execute:
+  python setup.py install
+"""
+
+import random
+import time
+
+import google_benchmark as benchmark
+from google_benchmark import Counter
+
+
+@benchmark.register
+def empty(state):
+    while state:
+        pass
+
+
+@benchmark.register
+def sum_million(state):
+    while state:
+        sum(range(1_000_000))
+
+
+@benchmark.register
+def pause_timing(state):
+    """Pause timing every iteration."""
+    while state:
+        # Construct a list of random ints every iteration without timing it
+        state.pause_timing()
+        random_list = [random.randint(0, 100) for _ in range(100)]
+        state.resume_timing()
+        # Time the in place sorting algorithm
+        random_list.sort()
+
+
+@benchmark.register
+def skipped(state):
+    if True:  # Test some predicate here.
+        state.skip_with_error("some error")
+        return  # NOTE: You must explicitly return, or benchmark will continue.
+
+    ...  # Benchmark code would be here.
+
+
+@benchmark.register
+def manual_timing(state):
+    while state:
+        # Manually count Python CPU time
+        start = time.perf_counter()  # perf_counter_ns() in Python 3.7+
+        # Something to benchmark
+        time.sleep(0.01)
+        end = time.perf_counter()
+        state.set_iteration_time(end - start)
+
+
+@benchmark.register
+def custom_counters(state):
+    """Collect custom metric using benchmark.Counter."""
+    num_foo = 0.0
+    while state:
+        # Benchmark some code here
+        pass
+        # Collect some custom metric named foo
+        num_foo += 0.13
+
+    # Automatic Counter from numbers.
+    state.counters["foo"] = num_foo
+    # Set a counter as a rate.
+    state.counters["foo_rate"] = Counter(num_foo, Counter.kIsRate)
+    #  Set a counter as an inverse of rate.
+    state.counters["foo_inv_rate"] = Counter(
+        num_foo, Counter.kIsRate | Counter.kInvert
+    )
+    # Set a counter as a thread-average quantity.
+    state.counters["foo_avg"] = Counter(num_foo, Counter.kAvgThreads)
+    # There's also a combined flag:
+    state.counters["foo_avg_rate"] = Counter(num_foo, Counter.kAvgThreadsRate)
+
+
+@benchmark.register
+@benchmark.option.measure_process_cpu_time()
+@benchmark.option.use_real_time()
+def with_options(state):
+    while state:
+        sum(range(1_000_000))
+
+
+@benchmark.register(name="sum_million_microseconds")
+@benchmark.option.unit(benchmark.kMicrosecond)
+def with_options2(state):
+    while state:
+        sum(range(1_000_000))
+
+
+@benchmark.register
+@benchmark.option.arg(100)
+@benchmark.option.arg(1000)
+def passing_argument(state):
+    while state:
+        sum(range(state.range(0)))
+
+
+@benchmark.register
+@benchmark.option.range(8, limit=8 << 10)
+def using_range(state):
+    while state:
+        sum(range(state.range(0)))
+
+
+@benchmark.register
+@benchmark.option.range_multiplier(2)
+@benchmark.option.range(1 << 10, 1 << 18)
+@benchmark.option.complexity(benchmark.oN)
+def computing_complexity(state):
+    while state:
+        sum(range(state.range(0)))
+    state.complexity_n = state.range(0)
+
+
+if __name__ == "__main__":
+    benchmark.main()

third_party/benchmark/bindings/python/google_benchmark/version.py

@@ -0,0 +1,7 @@
+from importlib.metadata import PackageNotFoundError, version
+
+try:
+    __version__ = version("google-benchmark")
+except PackageNotFoundError:
+    # package is not installed
+    pass

third_party/benchmark/cmake/AddCXXCompilerFlag.cmake

@@ -0,0 +1,78 @@
+# - Adds a compiler flag if it is supported by the compiler
+#
+# This function checks that the supplied compiler flag is supported and then
+# adds it to the corresponding compiler flags
+#
+#  add_cxx_compiler_flag(<FLAG> [<VARIANT>])
+#
+# - Example
+#
+# include(AddCXXCompilerFlag)
+# add_cxx_compiler_flag(-Wall)
+# add_cxx_compiler_flag(-no-strict-aliasing RELEASE)
+# Requires CMake 2.6+
+
+if(__add_cxx_compiler_flag)
+  return()
+endif()
+set(__add_cxx_compiler_flag INCLUDED)
+
+include(CheckCXXCompilerFlag)
+
+function(mangle_compiler_flag FLAG OUTPUT)
+  string(TOUPPER "HAVE_CXX_FLAG_${FLAG}" SANITIZED_FLAG)
+  string(REPLACE "+" "X" SANITIZED_FLAG ${SANITIZED_FLAG})
+  string(REGEX REPLACE "[^A-Za-z_0-9]" "_" SANITIZED_FLAG ${SANITIZED_FLAG})
+  string(REGEX REPLACE "_+" "_" SANITIZED_FLAG ${SANITIZED_FLAG})
+  set(${OUTPUT} "${SANITIZED_FLAG}" PARENT_SCOPE)
+endfunction(mangle_compiler_flag)
+
+function(add_cxx_compiler_flag FLAG)
+  mangle_compiler_flag("${FLAG}" MANGLED_FLAG)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")
+  check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})
+  set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
+  if(${MANGLED_FLAG})
+    if(ARGC GREATER 1)
+      set(VARIANT ${ARGV1})
+      string(TOUPPER "_${VARIANT}" VARIANT)
+    else()
+      set(VARIANT "")
+    endif()
+    set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${BENCHMARK_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(add_required_cxx_compiler_flag FLAG)
+  mangle_compiler_flag("${FLAG}" MANGLED_FLAG)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")
+  check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})
+  set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
+  if(${MANGLED_FLAG})
+    if(ARGC GREATER 1)
+      set(VARIANT ${ARGV1})
+      string(TOUPPER "_${VARIANT}" VARIANT)
+    else()
+      set(VARIANT "")
+    endif()
+    set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}" PARENT_SCOPE)
+  else()
+    message(FATAL_ERROR "Required flag '${FLAG}' is not supported by the compiler")
+  endif()
+endfunction()
+
+function(check_cxx_warning_flag FLAG)
+  mangle_compiler_flag("${FLAG}" MANGLED_FLAG)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  # Add -Werror to ensure the compiler generates an error if the warning flag
+  # doesn't exist.
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror ${FLAG}")
+  check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})
+  set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
+endfunction()

third_party/benchmark/cmake/CXXFeatureCheck.cmake

@@ -0,0 +1,82 @@
+# - Compile and run code to check for C++ features
+#
+# This functions compiles a source file under the `cmake` folder
+# and adds the corresponding `HAVE_[FILENAME]` flag to the CMake
+# environment
+#
+#  cxx_feature_check(<FLAG> [<VARIANT>])
+#
+# - Example
+#
+# include(CXXFeatureCheck)
+# cxx_feature_check(STD_REGEX)
+# Requires CMake 2.8.12+
+
+if(__cxx_feature_check)
+  return()
+endif()
+set(__cxx_feature_check INCLUDED)
+
+option(CXXFEATURECHECK_DEBUG OFF)
+
+function(cxx_feature_check FILE)
+  string(TOLOWER ${FILE} FILE)
+  string(TOUPPER ${FILE} VAR)
+  string(TOUPPER "HAVE_${VAR}" FEATURE)
+  if (DEFINED HAVE_${VAR})
+    set(HAVE_${VAR} 1 PARENT_SCOPE)
+    add_definitions(-DHAVE_${VAR})
+    return()
+  endif()
+
+  set(FEATURE_CHECK_CMAKE_FLAGS ${BENCHMARK_CXX_LINKER_FLAGS})
+  if (ARGC GREATER 1)
+    message(STATUS "Enabling additional flags: ${ARGV1}")
+    list(APPEND FEATURE_CHECK_CMAKE_FLAGS ${ARGV1})
+  endif()
+
+  if (NOT DEFINED COMPILE_${FEATURE})
+    if(CMAKE_CROSSCOMPILING)
+      message(STATUS "Cross-compiling to test ${FEATURE}")
+      try_compile(COMPILE_${FEATURE}
+              ${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${FILE}.cpp
+              CXX_STANDARD 11
+              CXX_STANDARD_REQUIRED ON
+              CMAKE_FLAGS ${FEATURE_CHECK_CMAKE_FLAGS}
+              LINK_LIBRARIES ${BENCHMARK_CXX_LIBRARIES}
+              OUTPUT_VARIABLE COMPILE_OUTPUT_VAR)
+      if(COMPILE_${FEATURE})
+        message(WARNING
+              "If you see build failures due to cross compilation, try setting HAVE_${VAR} to 0")
+        set(RUN_${FEATURE} 0 CACHE INTERNAL "")
+      else()
+        set(RUN_${FEATURE} 1 CACHE INTERNAL "")
+      endif()
+    else()
+      message(STATUS "Compiling and running to test ${FEATURE}")
+      try_run(RUN_${FEATURE} COMPILE_${FEATURE}
+              ${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${FILE}.cpp
+              CXX_STANDARD 11
+              CXX_STANDARD_REQUIRED ON
+              CMAKE_FLAGS ${FEATURE_CHECK_CMAKE_FLAGS}
+              LINK_LIBRARIES ${BENCHMARK_CXX_LIBRARIES}
+              COMPILE_OUTPUT_VARIABLE COMPILE_OUTPUT_VAR)
+    endif()
+  endif()
+
+  if(RUN_${FEATURE} EQUAL 0)
+    message(STATUS "Performing Test ${FEATURE} -- success")
+    set(HAVE_${VAR} 1 PARENT_SCOPE)
+    add_definitions(-DHAVE_${VAR})
+  else()
+    if(NOT COMPILE_${FEATURE})
+      if(CXXFEATURECHECK_DEBUG)
+        message(STATUS "Performing Test ${FEATURE} -- failed to compile: ${COMPILE_OUTPUT_VAR}")
+      else()
+        message(STATUS "Performing Test ${FEATURE} -- failed to compile")
+      endif()
+    else()
+      message(STATUS "Performing Test ${FEATURE} -- compiled but failed to run")
+    endif()
+  endif()
+endfunction()

third_party/benchmark/cmake/Config.cmake.in

@@ -0,0 +1,7 @@
+@PACKAGE_INIT@
+
+include (CMakeFindDependencyMacro)
+
+find_dependency (Threads)
+
+include("${CMAKE_CURRENT_LIST_DIR}/@targets_export_name@.cmake")

third_party/benchmark/cmake/GetGitVersion.cmake

@@ -0,0 +1,36 @@
+# - Returns a version string from Git tags
+#
+# This function inspects the annotated git tags for the project and returns a string
+# into a CMake variable
+#
+#  get_git_version(<var>)
+#
+# - Example
+#
+# include(GetGitVersion)
+# get_git_version(GIT_VERSION)
+#
+# Requires CMake 2.8.11+
+find_package(Git)
+
+if(__get_git_version)
+  return()
+endif()
+set(__get_git_version INCLUDED)
+
+function(get_git_version var)
+  if(GIT_EXECUTABLE)
+      execute_process(COMMAND ${GIT_EXECUTABLE} describe --tags --match "v[0-9]*.[0-9]*.[0-9]*" --abbrev=8 --dirty
+          WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+          RESULT_VARIABLE status
+          OUTPUT_VARIABLE GIT_VERSION
+          ERROR_QUIET)
+      if(status)
+          set(GIT_VERSION "v0.0.0")
+      endif()
+  else()
+      set(GIT_VERSION "v0.0.0")
+  endif()
+
+  set(${var} ${GIT_VERSION} PARENT_SCOPE)
+endfunction()

third_party/benchmark/cmake/GoogleTest.cmake

@@ -0,0 +1,58 @@
+# Download and unpack googletest at configure time
+set(GOOGLETEST_PREFIX "${benchmark_BINARY_DIR}/third_party/googletest")
+configure_file(${benchmark_SOURCE_DIR}/cmake/GoogleTest.cmake.in ${GOOGLETEST_PREFIX}/CMakeLists.txt @ONLY)
+
+set(GOOGLETEST_PATH "${CMAKE_CURRENT_SOURCE_DIR}/googletest" CACHE PATH "") # Mind the quotes
+execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}"
+  -DALLOW_DOWNLOADING_GOOGLETEST=${BENCHMARK_DOWNLOAD_DEPENDENCIES} -DGOOGLETEST_PATH:PATH=${GOOGLETEST_PATH} .
+  RESULT_VARIABLE result
+  WORKING_DIRECTORY ${GOOGLETEST_PREFIX}
+)
+
+if(result)
+  message(FATAL_ERROR "CMake step for googletest failed: ${result}")
+endif()
+
+execute_process(
+  COMMAND ${CMAKE_COMMAND} --build .
+  RESULT_VARIABLE result
+  WORKING_DIRECTORY ${GOOGLETEST_PREFIX}
+)
+
+if(result)
+  message(FATAL_ERROR "Build step for googletest failed: ${result}")
+endif()
+
+# Prevent overriding the parent project's compiler/linker
+# settings on Windows
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+
+include(${GOOGLETEST_PREFIX}/googletest-paths.cmake)
+
+# Add googletest directly to our build. This defines
+# the gtest and gtest_main targets.
+add_subdirectory(${GOOGLETEST_SOURCE_DIR}
+                 ${GOOGLETEST_BINARY_DIR}
+                 EXCLUDE_FROM_ALL)
+
+# googletest doesn't seem to want to stay build warning clean so let's not hurt ourselves.
+if (MSVC)
+  target_compile_options(gtest PRIVATE "/wd4244" "/wd4722")
+  target_compile_options(gtest_main PRIVATE "/wd4244" "/wd4722")
+  target_compile_options(gmock PRIVATE "/wd4244" "/wd4722")
+  target_compile_options(gmock_main PRIVATE "/wd4244" "/wd4722")
+else()
+  target_compile_options(gtest PRIVATE "-w")
+  target_compile_options(gtest_main PRIVATE "-w")
+  target_compile_options(gmock PRIVATE "-w")
+  target_compile_options(gmock_main PRIVATE "-w")
+endif()
+
+if(NOT DEFINED GTEST_COMPILE_COMMANDS)
+    set(GTEST_COMPILE_COMMANDS ON)
+endif()
+
+set_target_properties(gtest PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES $<TARGET_PROPERTY:gtest,INTERFACE_INCLUDE_DIRECTORIES> EXPORT_COMPILE_COMMANDS ${GTEST_COMPILE_COMMANDS})
+set_target_properties(gtest_main PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES $<TARGET_PROPERTY:gtest_main,INTERFACE_INCLUDE_DIRECTORIES> EXPORT_COMPILE_COMMANDS ${GTEST_COMPILE_COMMANDS})
+set_target_properties(gmock PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES $<TARGET_PROPERTY:gmock,INTERFACE_INCLUDE_DIRECTORIES> EXPORT_COMPILE_COMMANDS ${GTEST_COMPILE_COMMANDS})
+set_target_properties(gmock_main PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES $<TARGET_PROPERTY:gmock_main,INTERFACE_INCLUDE_DIRECTORIES> EXPORT_COMPILE_COMMANDS ${GTEST_COMPILE_COMMANDS})

third_party/benchmark/cmake/GoogleTest.cmake.in

@@ -0,0 +1,59 @@
+cmake_minimum_required(VERSION 2.8.12)
+
+project(googletest-download NONE)
+
+# Enable ExternalProject CMake module
+include(ExternalProject)
+
+option(ALLOW_DOWNLOADING_GOOGLETEST "If googletest src tree is not found in location specified by GOOGLETEST_PATH, do fetch the archive from internet" OFF)
+set(GOOGLETEST_PATH "/usr/src/googletest" CACHE PATH
+                    "Path to the googletest root tree. Should contain googletest and googlemock subdirs. And CMakeLists.txt in root, and in both of these subdirs")
+
+# Download and install GoogleTest
+
+message(STATUS "Looking for Google Test sources")
+message(STATUS "Looking for Google Test sources in ${GOOGLETEST_PATH}")
+if(EXISTS "${GOOGLETEST_PATH}"            AND IS_DIRECTORY "${GOOGLETEST_PATH}"            AND EXISTS "${GOOGLETEST_PATH}/CMakeLists.txt" AND
+   EXISTS "${GOOGLETEST_PATH}/googletest" AND IS_DIRECTORY "${GOOGLETEST_PATH}/googletest" AND EXISTS "${GOOGLETEST_PATH}/googletest/CMakeLists.txt" AND
+   EXISTS "${GOOGLETEST_PATH}/googlemock" AND IS_DIRECTORY "${GOOGLETEST_PATH}/googlemock" AND EXISTS "${GOOGLETEST_PATH}/googlemock/CMakeLists.txt")
+  message(STATUS "Found Google Test in ${GOOGLETEST_PATH}")
+
+  ExternalProject_Add(
+    googletest
+    PREFIX            "${CMAKE_BINARY_DIR}"
+    DOWNLOAD_DIR      "${CMAKE_BINARY_DIR}/download"
+    SOURCE_DIR        "${GOOGLETEST_PATH}" # use existing src dir.
+    BINARY_DIR        "${CMAKE_BINARY_DIR}/build"
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND     ""
+    INSTALL_COMMAND   ""
+    TEST_COMMAND      ""
+  )
+else()
+  if(NOT ALLOW_DOWNLOADING_GOOGLETEST)
+    message(SEND_ERROR "Did not find Google Test sources! Either pass correct path in GOOGLETEST_PATH, or enable BENCHMARK_DOWNLOAD_DEPENDENCIES, or disable BENCHMARK_USE_BUNDLED_GTEST, or disable BENCHMARK_ENABLE_GTEST_TESTS / BENCHMARK_ENABLE_TESTING.")
+    return()
+  else()
+    message(WARNING "Did not find Google Test sources! Fetching from web...")
+    ExternalProject_Add(
+      googletest
+      GIT_REPOSITORY    https://github.com/google/googletest.git
+      GIT_TAG           "release-1.11.0"
+      PREFIX            "${CMAKE_BINARY_DIR}"
+      STAMP_DIR         "${CMAKE_BINARY_DIR}/stamp"
+      DOWNLOAD_DIR      "${CMAKE_BINARY_DIR}/download"
+      SOURCE_DIR        "${CMAKE_BINARY_DIR}/src"
+      BINARY_DIR        "${CMAKE_BINARY_DIR}/build"
+      CONFIGURE_COMMAND ""
+      BUILD_COMMAND     ""
+      INSTALL_COMMAND   ""
+      TEST_COMMAND      ""
+    )
+  endif()
+endif()
+
+ExternalProject_Get_Property(googletest SOURCE_DIR BINARY_DIR)
+file(WRITE googletest-paths.cmake
+"set(GOOGLETEST_SOURCE_DIR \"${SOURCE_DIR}\")
+set(GOOGLETEST_BINARY_DIR \"${BINARY_DIR}\")
+")

third_party/benchmark/cmake/benchmark.pc.in

@@ -0,0 +1,12 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=${prefix}
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
+
+Name: @PROJECT_NAME@
+Description: Google microbenchmark framework
+Version: @VERSION@
+
+Libs: -L${libdir} -lbenchmark
+Libs.private: -lpthread
+Cflags: -I${includedir}

third_party/benchmark/cmake/benchmark_main.pc.in

@@ -0,0 +1,7 @@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+
+Name: @PROJECT_NAME@
+Description: Google microbenchmark framework (with main() function)
+Version: @VERSION@
+Requires: benchmark
+Libs: -L${libdir} -lbenchmark_main

third_party/benchmark/cmake/gnu_posix_regex.cpp

@@ -0,0 +1,12 @@
+#include <gnuregex.h>
+#include <string>
+int main() {
+  std::string str = "test0159";
+  regex_t re;
+  int ec = regcomp(&re, "^[a-z]+[0-9]+$", REG_EXTENDED | REG_NOSUB);
+  if (ec != 0) {
+    return ec;
+  }
+  return regexec(&re, str.c_str(), 0, nullptr, 0) ? -1 : 0;
+}
+

third_party/benchmark/cmake/llvm-toolchain.cmake

@@ -0,0 +1,8 @@
+find_package(LLVMAr REQUIRED)
+set(CMAKE_AR "${LLVMAR_EXECUTABLE}" CACHE FILEPATH "" FORCE)
+
+find_package(LLVMNm REQUIRED)
+set(CMAKE_NM "${LLVMNM_EXECUTABLE}" CACHE FILEPATH "" FORCE)
+
+find_package(LLVMRanLib REQUIRED)
+set(CMAKE_RANLIB "${LLVMRANLIB_EXECUTABLE}" CACHE FILEPATH "" FORCE)

third_party/benchmark/cmake/posix_regex.cpp

@@ -0,0 +1,14 @@
+#include <regex.h>
+#include <string>
+int main() {
+  std::string str = "test0159";
+  regex_t re;
+  int ec = regcomp(&re, "^[a-z]+[0-9]+$", REG_EXTENDED | REG_NOSUB);
+  if (ec != 0) {
+    return ec;
+  }
+  int ret = regexec(&re, str.c_str(), 0, nullptr, 0) ? -1 : 0;
+  regfree(&re);
+  return ret;
+}
+

third_party/benchmark/cmake/pthread_affinity.cpp

@@ -0,0 +1,16 @@
+#include <pthread.h>
+int main() {
+  cpu_set_t set;
+  CPU_ZERO(&set);
+  for (int i = 0; i < CPU_SETSIZE; ++i) {
+    CPU_SET(i, &set);
+    CPU_CLR(i, &set);
+  }
+  pthread_t self = pthread_self();
+  int ret;
+  ret = pthread_getaffinity_np(self, sizeof(set), &set);
+  if (ret != 0) return ret;
+  ret = pthread_setaffinity_np(self, sizeof(set), &set);
+  if (ret != 0) return ret;
+  return 0;
+}

third_party/benchmark/cmake/split_list.cmake

@@ -0,0 +1,3 @@
+macro(split_list listname)
+  string(REPLACE ";" " " ${listname} "${${listname}}")
+endmacro()

third_party/benchmark/cmake/std_regex.cpp

@@ -0,0 +1,10 @@
+#include <regex>
+#include <string>
+int main() {
+  const std::string str = "test0159";
+  std::regex re;
+  re = std::regex("^[a-z]+[0-9]+$",
+       std::regex_constants::extended | std::regex_constants::nosubs);
+  return std::regex_search(str, re) ? 0 : -1;
+}
+

third_party/benchmark/cmake/steady_clock.cpp

@@ -0,0 +1,7 @@
+#include <chrono>
+
+int main() {
+    typedef std::chrono::steady_clock Clock;
+    Clock::time_point tp = Clock::now();
+    ((void)tp);
+}

third_party/benchmark/cmake/thread_safety_attributes.cpp

@@ -0,0 +1,4 @@
+#define HAVE_THREAD_SAFETY_ATTRIBUTES
+#include "../src/mutex.h"
+
+int main() {}

third_party/benchmark/docs/AssemblyTests.md

@@ -0,0 +1,149 @@
+# Assembly Tests
+
+The Benchmark library provides a number of functions whose primary
+purpose in to affect assembly generation, including `DoNotOptimize`
+and `ClobberMemory`. In addition there are other functions,
+such as `KeepRunning`, for which generating good assembly is paramount.
+
+For these functions it's important to have tests that verify the
+correctness and quality of the implementation. This requires testing
+the code generated by the compiler.
+
+This document describes how the Benchmark library tests compiler output,
+as well as how to properly write new tests.
+
+
+## Anatomy of a Test
+
+Writing a test has two steps:
+
+* Write the code you want to generate assembly for.
+* Add `// CHECK` lines to match against the verified assembly.
+
+Example:
+```c++
+
+// CHECK-LABEL: test_add:
+extern "C" int test_add() {
+    extern int ExternInt;
+    return ExternInt + 1;
+
+    // CHECK: movl ExternInt(%rip), %eax
+    // CHECK: addl %eax
+    // CHECK: ret
+}
+
+```
+
+#### LLVM Filecheck
+
+[LLVM's Filecheck](https://llvm.org/docs/CommandGuide/FileCheck.html)
+is used to test the generated assembly against the `// CHECK` lines
+specified in the tests source file. Please see the documentation
+linked above for information on how to write `CHECK` directives.
+
+#### Tips and Tricks:
+
+* Tests should match the minimal amount of output required to establish
+correctness. `CHECK` directives don't have to match on the exact next line
+after the previous match, so tests should omit checks for unimportant
+bits of assembly. ([`CHECK-NEXT`](https://llvm.org/docs/CommandGuide/FileCheck.html#the-check-next-directive)
+can be used to ensure a match occurs exactly after the previous match).
+
+* The tests are compiled with `-O3 -g0`. So we're only testing the
+optimized output.
+
+* The assembly output is further cleaned up using `tools/strip_asm.py`.
+This removes comments, assembler directives, and unused labels before
+the test is run.
+
+* The generated and stripped assembly file for a test is output under
+`<build-directory>/test/<test-name>.s`
+
+* Filecheck supports using [`CHECK` prefixes](https://llvm.org/docs/CommandGuide/FileCheck.html#cmdoption-check-prefixes)
+to specify lines that should only match in certain situations.
+The Benchmark tests use `CHECK-CLANG` and `CHECK-GNU` for lines that
+are only expected to match Clang or GCC's output respectively. Normal
+`CHECK` lines match against all compilers. (Note: `CHECK-NOT` and
+`CHECK-LABEL` are NOT prefixes. They are versions of non-prefixed
+`CHECK` lines)
+
+* Use `extern "C"` to disable name mangling for specific functions. This
+makes them easier to name in the `CHECK` lines.
+
+
+## Problems Writing Portable Tests
+
+Writing tests which check the code generated by a compiler are
+inherently non-portable. Different compilers and even different compiler
+versions may generate entirely different code. The Benchmark tests
+must tolerate this.
+
+LLVM Filecheck provides a number of mechanisms to help write
+"more portable" tests; including [matching using regular expressions](https://llvm.org/docs/CommandGuide/FileCheck.html#filecheck-pattern-matching-syntax),
+allowing the creation of [named variables](https://llvm.org/docs/CommandGuide/FileCheck.html#filecheck-variables)
+for later matching, and [checking non-sequential matches](https://llvm.org/docs/CommandGuide/FileCheck.html#the-check-dag-directive).
+
+#### Capturing Variables
+
+For example, say GCC stores a variable in a register but Clang stores
+it in memory. To write a test that tolerates both cases we "capture"
+the destination of the store, and then use the captured expression
+to write the remainder of the test.
+
+```c++
+// CHECK-LABEL: test_div_no_op_into_shr:
+extern "C" void test_div_no_op_into_shr(int value) {
+    int divisor = 2;
+    benchmark::DoNotOptimize(divisor); // hide the value from the optimizer
+    return value / divisor;
+
+    // CHECK: movl $2, [[DEST:.*]]
+    // CHECK: idivl [[DEST]]
+    // CHECK: ret
+}
+```
+
+#### Using Regular Expressions to Match Differing Output
+
+Often tests require testing assembly lines which may subtly differ
+between compilers or compiler versions. A common example of this
+is matching stack frame addresses. In this case regular expressions
+can be used to match the differing bits of output. For example:
+
+<!-- {% raw %} -->
+```c++
+int ExternInt;
+struct Point { int x, y, z; };
+
+// CHECK-LABEL: test_store_point:
+extern "C" void test_store_point() {
+    Point p{ExternInt, ExternInt, ExternInt};
+    benchmark::DoNotOptimize(p);
+
+    // CHECK: movl ExternInt(%rip), %eax
+    // CHECK: movl %eax, -{{[0-9]+}}(%rsp)
+    // CHECK: movl %eax, -{{[0-9]+}}(%rsp)
+    // CHECK: movl %eax, -{{[0-9]+}}(%rsp)
+    // CHECK: ret
+}
+```
+<!-- {% endraw %} -->
+
+## Current Requirements and Limitations
+
+The tests require Filecheck to be installed along the `PATH` of the
+build machine. Otherwise the tests will be disabled.
+
+Additionally, as mentioned in the previous section, codegen tests are
+inherently non-portable. Currently the tests are limited to:
+
+* x86_64 targets.
+* Compiled with GCC or Clang
+
+Further work could be done, at least on a limited basis, to extend the
+tests to other architectures and compilers (using `CHECK` prefixes).
+
+Furthermore, the tests fail for builds which specify additional flags
+that modify code generation, including `--coverage` or `-fsanitize=`.
+

third_party/benchmark/docs/_config.yml

@@ -0,0 +1,3 @@
+theme: jekyll-theme-minimal
+logo: /assets/images/icon_black.png
+show_downloads: true

third_party/benchmark/docs/dependencies.md

@@ -0,0 +1,13 @@
+# Build tool dependency policy
+
+We follow the [Foundational C++ support policy](https://opensource.google/documentation/policies/cplusplus-support) for our build tools. In
+particular the ["Build Systems" section](https://opensource.google/documentation/policies/cplusplus-support#build-systems).
+
+## CMake
+
+The current supported version is CMake 3.10 as of 2023-08-10. Most modern
+distributions include newer versions, for example:
+
+* Ubuntu 20.04 provides CMake 3.16.3
+* Debian 11.4 provides CMake 3.18.4
+* Ubuntu 22.04 provides CMake 3.22.1

third_party/benchmark/docs/index.md

@@ -0,0 +1,12 @@
+# Benchmark
+
+* [Assembly Tests](AssemblyTests.md)
+* [Dependencies](dependencies.md)
+* [Perf Counters](perf_counters.md)
+* [Platform Specific Build Instructions](platform_specific_build_instructions.md)
+* [Python Bindings](python_bindings.md)
+* [Random Interleaving](random_interleaving.md)
+* [Reducing Variance](reducing_variance.md)
+* [Releasing](releasing.md)
+* [Tools](tools.md)
+* [User Guide](user_guide.md)

third_party/benchmark/docs/perf_counters.md

@@ -0,0 +1,35 @@
+<a name="perf-counters" />
+
+# User-Requested Performance Counters
+
+When running benchmarks, the user may choose to request collection of
+performance counters. This may be useful in investigation scenarios - narrowing
+down the cause of a regression; or verifying that the underlying cause of a
+performance improvement matches expectations.
+
+This feature is available if:
+
+* The benchmark is run on an architecture featuring a Performance Monitoring
+  Unit (PMU),
+* The benchmark is compiled with support for collecting counters. Currently,
+  this requires [libpfm](http://perfmon2.sourceforge.net/), which is built as a
+  dependency via Bazel.
+
+The feature does not require modifying benchmark code. Counter collection is
+handled at the boundaries where timer collection is also handled. 
+
+To opt-in:
+* If using a Bazel build, add `--define pfm=1` to your build flags
+* If using CMake:
+  * Install `libpfm4-dev`, e.g. `apt-get install libpfm4-dev`.
+  * Enable the CMake flag `BENCHMARK_ENABLE_LIBPFM` in `CMakeLists.txt`.
+
+To use, pass a comma-separated list of counter names through the
+`--benchmark_perf_counters` flag. The names are decoded through libpfm - meaning,
+they are platform specific, but some (e.g. `CYCLES` or `INSTRUCTIONS`) are
+mapped by libpfm to platform-specifics - see libpfm
+[documentation](http://perfmon2.sourceforge.net/docs.html) for more details.
+
+The counter values are reported back through the [User Counters](../README.md#custom-counters)
+mechanism, meaning, they are available in all the formats (e.g. JSON) supported
+by User Counters.

third_party/benchmark/docs/platform_specific_build_instructions.md

@@ -0,0 +1,48 @@
+# Platform Specific Build Instructions
+
+## Building with GCC
+
+When the library is built using GCC it is necessary to link with the pthread
+library due to how GCC implements `std::thread`. Failing to link to pthread will
+lead to runtime exceptions (unless you're using libc++), not linker errors. See
+[issue #67](https://github.com/google/benchmark/issues/67) for more details. You
+can link to pthread by adding `-pthread` to your linker command. Note, you can
+also use `-lpthread`, but there are potential issues with ordering of command
+line parameters if you use that.
+
+On QNX, the pthread library is part of libc and usually included automatically
+(see
+[`pthread_create()`](https://www.qnx.com/developers/docs/7.1/index.html#com.qnx.doc.neutrino.lib_ref/topic/p/pthread_create.html)).
+There's no separate pthread library to link.
+
+## Building with Visual Studio 2015 or 2017
+
+The `shlwapi` library (`-lshlwapi`) is required to support a call to `CPUInfo` which reads the registry. Either add `shlwapi.lib` under `[ Configuration Properties > Linker > Input ]`, or use the following:
+
+```
+// Alternatively, can add libraries using linker options.
+#ifdef _WIN32
+#pragma comment ( lib, "Shlwapi.lib" )
+#ifdef _DEBUG
+#pragma comment ( lib, "benchmarkd.lib" )
+#else
+#pragma comment ( lib, "benchmark.lib" )
+#endif
+#endif
+```
+
+Can also use the graphical version of CMake:
+* Open `CMake GUI`.
+* Under `Where to build the binaries`, same path as source plus `build`.
+* Under `CMAKE_INSTALL_PREFIX`, same path as source plus `install`.
+* Click `Configure`, `Generate`, `Open Project`.
+* If build fails, try deleting entire directory and starting again, or unticking options to build less.
+
+## Building with Intel 2015 Update 1 or Intel System Studio Update 4
+
+See instructions for building with Visual Studio. Once built, right click on the solution and change the build to Intel.
+
+## Building on Solaris
+
+If you're running benchmarks on solaris, you'll want the kstat library linked in
+too (`-lkstat`).

third_party/benchmark/docs/python_bindings.md

@@ -0,0 +1,34 @@
+# Building and installing Python bindings
+
+Python bindings are available as wheels on [PyPI](https://pypi.org/project/google-benchmark/) for importing and 
+using Google Benchmark directly in Python. 
+Currently, pre-built wheels exist for macOS (both ARM64 and Intel x86), Linux x86-64 and 64-bit Windows.
+Supported Python versions are Python 3.8 - 3.12.
+
+To install Google Benchmark's Python bindings, run:
+
+```bash
+python -m pip install --upgrade pip  # for manylinux2014 support
+python -m pip install google-benchmark
+```
+
+In order to keep your system Python interpreter clean, it is advisable to run these commands in a virtual
+environment. See the [official Python documentation](https://docs.python.org/3/library/venv.html) 
+on how to create virtual environments.
+
+To build a wheel directly from source, you can follow these steps:
+```bash
+git clone https://github.com/google/benchmark.git
+cd benchmark
+# create a virtual environment and activate it
+python3 -m venv venv --system-site-packages
+source venv/bin/activate  # .\venv\Scripts\Activate.ps1 on Windows
+
+# upgrade Python's system-wide packages
+python -m pip install --upgrade pip build
+# builds the wheel and stores it in the directory "dist".
+python -m build
+```
+
+NB: Building wheels from source requires Bazel. For platform-specific instructions on how to install Bazel,
+refer to the [Bazel installation docs](https://bazel.build/install).

third_party/benchmark/docs/random_interleaving.md

@@ -0,0 +1,13 @@
+<a name="interleaving" />
+
+# Random Interleaving
+
+[Random Interleaving](https://github.com/google/benchmark/issues/1051) is a
+technique to lower run-to-run variance. It randomly interleaves repetitions of a
+microbenchmark with repetitions from other microbenchmarks in the same benchmark
+test. Data shows it is able to lower run-to-run variance by
+[40%](https://github.com/google/benchmark/issues/1051) on average.
+
+To use, you mainly need to set `--benchmark_enable_random_interleaving=true`,
+and optionally specify non-zero repetition count `--benchmark_repetitions=9`
+and optionally decrease the per-repetition time `--benchmark_min_time=0.1`.

third_party/benchmark/docs/reducing_variance.md

@@ -0,0 +1,98 @@
+# Reducing Variance
+
+<a name="disabling-cpu-frequency-scaling" />
+
+## Disabling CPU Frequency Scaling
+
+If you see this error:
+
+```
+***WARNING*** CPU scaling is enabled, the benchmark real time measurements may be noisy and will incur extra overhead.
+```
+
+you might want to disable the CPU frequency scaling while running the
+benchmark, as well as consider other ways to stabilize the performance of
+your system while benchmarking.
+
+Exactly how to do this depends on the Linux distribution,
+desktop environment, and installed programs.  Specific details are a moving
+target, so we will not attempt to exhaustively document them here.
+
+One simple option is to use the `cpupower` program to change the
+performance governor to "performance".  This tool is maintained along with
+the Linux kernel and provided by your distribution.
+
+It must be run as root, like this:
+
+```bash
+sudo cpupower frequency-set --governor performance
+```
+
+After this you can verify that all CPUs are using the performance governor
+by running this command:
+
+```bash
+cpupower frequency-info -o proc
+```
+
+The benchmarks you subsequently run will have less variance.
+
+<a name="reducing-variance" />
+
+## Reducing Variance in Benchmarks
+
+The Linux CPU frequency governor [discussed
+above](user_guide#disabling-cpu-frequency-scaling) is not the only source
+of noise in benchmarks.  Some, but not all, of the sources of variance
+include:
+
+1. On multi-core machines not all CPUs/CPU cores/CPU threads run the same
+   speed, so running a benchmark one time and then again may give a
+   different result depending on which CPU it ran on.
+2. CPU scaling features that run on the CPU, like Intel's Turbo Boost and
+   AMD Turbo Core and Precision Boost, can temporarily change the CPU
+   frequency even when the using the "performance" governor on Linux.
+3. Context switching between CPUs, or scheduling competition on the CPU the
+   benchmark is running on.
+4. Intel Hyperthreading or AMD SMT causing the same issue as above.
+5. Cache effects caused by code running on other CPUs.
+6. Non-uniform memory architectures (NUMA).
+
+These can cause variance in benchmarks results within a single run
+(`--benchmark_repetitions=N`) or across multiple runs of the benchmark
+program.
+
+Reducing sources of variance is OS and architecture dependent, which is one
+reason some companies maintain machines dedicated to performance testing.
+
+Some of the easier and effective ways of reducing variance on a typical
+Linux workstation are:
+
+1. Use the performance governor as [discussed
+above](user_guide#disabling-cpu-frequency-scaling).
+1. Disable processor boosting by:
+   ```sh
+   echo 0 | sudo tee /sys/devices/system/cpu/cpufreq/boost
+   ```
+   See the Linux kernel's
+   [boost.txt](https://www.kernel.org/doc/Documentation/cpu-freq/boost.txt)
+   for more information.
+2. Set the benchmark program's task affinity to a fixed cpu.  For example:
+   ```sh
+   taskset -c 0 ./mybenchmark
+   ```
+3. Disabling Hyperthreading/SMT.  This can be done in the Bios or using the
+   `/sys` file system (see the LLVM project's [Benchmarking
+   tips](https://llvm.org/docs/Benchmarking.html)).
+4. Close other programs that do non-trivial things based on timers, such as
+   your web browser, desktop environment, etc.
+5. Reduce the working set of your benchmark to fit within the L1 cache, but
+   do be aware that this may lead you to optimize for an unrealistic
+   situation.
+
+Further resources on this topic:
+
+1. The LLVM project's [Benchmarking
+   tips](https://llvm.org/docs/Benchmarking.html).
+1. The Arch Wiki [Cpu frequency
+scaling](https://wiki.archlinux.org/title/CPU_frequency_scaling) page.

third_party/benchmark/docs/releasing.md

@@ -0,0 +1,31 @@
+# How to release
+
+* Make sure you're on main and synced to HEAD
+* Ensure the project builds and tests run
+    * `parallel -j0 exec ::: test/*_test` can help ensure everything at least
+      passes
+* Prepare release notes
+    * `git log $(git describe --abbrev=0 --tags)..HEAD` gives you the list of
+      commits between the last annotated tag and HEAD
+    * Pick the most interesting.
+* Create one last commit that updates the version saved in `CMakeLists.txt` and `MODULE.bazel`
+  to the release version you're creating. (This version will be used if benchmark is installed
+  from the archive you'll be creating in the next step.)
+
+```
+project (benchmark VERSION 1.8.0 LANGUAGES CXX)
+```
+
+```
+module(name = "com_github_google_benchmark", version="1.8.0")
+```
+
+* Create a release through github's interface
+    * Note this will create a lightweight tag.
+    * Update this to an annotated tag:
+      * `git pull --tags`
+      * `git tag -a -f <tag> <tag>`
+      * `git push --force --tags origin`
+* Confirm that the "Build and upload Python wheels" action runs to completion
+    * Run it manually if it hasn't run.
+    * IMPORTANT: When re-running manually, make sure to select the newly created `<tag>` as the workflow version in the "Run workflow" tab on the GitHub Actions page. 

third_party/benchmark/docs/tools.md

@@ -0,0 +1,343 @@
+# Benchmark Tools
+
+## compare.py
+
+The `compare.py` can be used to compare the result of benchmarks.
+
+### Dependencies
+The utility relies on the [scipy](https://www.scipy.org) package which can be installed using pip:
+```bash
+pip3 install -r requirements.txt
+```
+
+### Displaying aggregates only
+
+The switch `-a` / `--display_aggregates_only` can be used to control the
+displayment of the normal iterations vs the aggregates. When passed, it will
+be passthrough to the benchmark binaries to be run, and will be accounted for
+in the tool itself; only the aggregates will be displayed, but not normal runs.
+It only affects the display, the separate runs will still be used to calculate
+the U test.
+
+### Modes of operation
+
+There are three modes of operation:
+
+1. Just compare two benchmarks
+The program is invoked like:
+
+``` bash
+$ compare.py benchmarks <benchmark_baseline> <benchmark_contender> [benchmark options]...
+```
+Where `<benchmark_baseline>` and `<benchmark_contender>` either specify a benchmark executable file, or a JSON output file. The type of the input file is automatically detected. If a benchmark executable is specified then the benchmark is run to obtain the results. Otherwise the results are simply loaded from the output file.
+
+`[benchmark options]` will be passed to the benchmarks invocations. They can be anything that binary accepts, be it either normal `--benchmark_*` parameters, or some custom parameters your binary takes.
+
+Example output:
+```
+$ ./compare.py benchmarks ./a.out ./a.out
+RUNNING: ./a.out --benchmark_out=/tmp/tmprBT5nW
+Run on (8 X 4000 MHz CPU s)
+2017-11-07 21:16:44
+------------------------------------------------------
+Benchmark               Time           CPU Iterations
+------------------------------------------------------
+BM_memcpy/8            36 ns         36 ns   19101577   211.669MB/s
+BM_memcpy/64           76 ns         76 ns    9412571   800.199MB/s
+BM_memcpy/512          84 ns         84 ns    8249070   5.64771GB/s
+BM_memcpy/1024        116 ns        116 ns    6181763   8.19505GB/s
+BM_memcpy/8192        643 ns        643 ns    1062855   11.8636GB/s
+BM_copy/8             222 ns        222 ns    3137987   34.3772MB/s
+BM_copy/64           1608 ns       1608 ns     432758   37.9501MB/s
+BM_copy/512         12589 ns      12589 ns      54806   38.7867MB/s
+BM_copy/1024        25169 ns      25169 ns      27713   38.8003MB/s
+BM_copy/8192       201165 ns     201112 ns       3486   38.8466MB/s
+RUNNING: ./a.out --benchmark_out=/tmp/tmpt1wwG_
+Run on (8 X 4000 MHz CPU s)
+2017-11-07 21:16:53
+------------------------------------------------------
+Benchmark               Time           CPU Iterations
+------------------------------------------------------
+BM_memcpy/8            36 ns         36 ns   19397903   211.255MB/s
+BM_memcpy/64           73 ns         73 ns    9691174   839.635MB/s
+BM_memcpy/512          85 ns         85 ns    8312329   5.60101GB/s
+BM_memcpy/1024        118 ns        118 ns    6438774   8.11608GB/s
+BM_memcpy/8192        656 ns        656 ns    1068644   11.6277GB/s
+BM_copy/8             223 ns        223 ns    3146977   34.2338MB/s
+BM_copy/64           1611 ns       1611 ns     435340   37.8751MB/s
+BM_copy/512         12622 ns      12622 ns      54818   38.6844MB/s
+BM_copy/1024        25257 ns      25239 ns      27779   38.6927MB/s
+BM_copy/8192       205013 ns     205010 ns       3479    38.108MB/s
+Comparing ./a.out to ./a.out
+Benchmark                 Time             CPU      Time Old      Time New       CPU Old       CPU New
+------------------------------------------------------------------------------------------------------
+BM_memcpy/8            +0.0020         +0.0020            36            36            36            36
+BM_memcpy/64           -0.0468         -0.0470            76            73            76            73
+BM_memcpy/512          +0.0081         +0.0083            84            85            84            85
+BM_memcpy/1024         +0.0098         +0.0097           116           118           116           118
+BM_memcpy/8192         +0.0200         +0.0203           643           656           643           656
+BM_copy/8              +0.0046         +0.0042           222           223           222           223
+BM_copy/64             +0.0020         +0.0020          1608          1611          1608          1611
+BM_copy/512            +0.0027         +0.0026         12589         12622         12589         12622
+BM_copy/1024           +0.0035         +0.0028         25169         25257         25169         25239
+BM_copy/8192           +0.0191         +0.0194        201165        205013        201112        205010
+```
+
+What it does is for the every benchmark from the first run it looks for the benchmark with exactly the same name in the second run, and then compares the results. If the names differ, the benchmark is omitted from the diff.
+As you can note, the values in `Time` and `CPU` columns are calculated as `(new - old) / |old|`.
+
+2. Compare two different filters of one benchmark
+The program is invoked like:
+
+``` bash
+$ compare.py filters <benchmark> <filter_baseline> <filter_contender> [benchmark options]...
+```
+Where `<benchmark>` either specify a benchmark executable file, or a JSON output file. The type of the input file is automatically detected. If a benchmark executable is specified then the benchmark is run to obtain the results. Otherwise the results are simply loaded from the output file.
+
+Where `<filter_baseline>` and `<filter_contender>` are the same regex filters that you would pass to the `[--benchmark_filter=<regex>]` parameter of the benchmark binary.
+
+`[benchmark options]` will be passed to the benchmarks invocations. They can be anything that binary accepts, be it either normal `--benchmark_*` parameters, or some custom parameters your binary takes.
+
+Example output:
+```
+$ ./compare.py filters ./a.out BM_memcpy BM_copy
+RUNNING: ./a.out --benchmark_filter=BM_memcpy --benchmark_out=/tmp/tmpBWKk0k
+Run on (8 X 4000 MHz CPU s)
+2017-11-07 21:37:28
+------------------------------------------------------
+Benchmark               Time           CPU Iterations
+------------------------------------------------------
+BM_memcpy/8            36 ns         36 ns   17891491   211.215MB/s
+BM_memcpy/64           74 ns         74 ns    9400999   825.646MB/s
+BM_memcpy/512          87 ns         87 ns    8027453   5.46126GB/s
+BM_memcpy/1024        111 ns        111 ns    6116853    8.5648GB/s
+BM_memcpy/8192        657 ns        656 ns    1064679   11.6247GB/s
+RUNNING: ./a.out --benchmark_filter=BM_copy --benchmark_out=/tmp/tmpAvWcOM
+Run on (8 X 4000 MHz CPU s)
+2017-11-07 21:37:33
+----------------------------------------------------
+Benchmark             Time           CPU Iterations
+----------------------------------------------------
+BM_copy/8           227 ns        227 ns    3038700   33.6264MB/s
+BM_copy/64         1640 ns       1640 ns     426893   37.2154MB/s
+BM_copy/512       12804 ns      12801 ns      55417   38.1444MB/s
+BM_copy/1024      25409 ns      25407 ns      27516   38.4365MB/s
+BM_copy/8192     202986 ns     202990 ns       3454   38.4871MB/s
+Comparing BM_memcpy to BM_copy (from ./a.out)
+Benchmark                               Time             CPU      Time Old      Time New       CPU Old       CPU New
+--------------------------------------------------------------------------------------------------------------------
+[BM_memcpy vs. BM_copy]/8            +5.2829         +5.2812            36           227            36           227
+[BM_memcpy vs. BM_copy]/64          +21.1719        +21.1856            74          1640            74          1640
+[BM_memcpy vs. BM_copy]/512        +145.6487       +145.6097            87         12804            87         12801
+[BM_memcpy vs. BM_copy]/1024       +227.1860       +227.1776           111         25409           111         25407
+[BM_memcpy vs. BM_copy]/8192       +308.1664       +308.2898           657        202986           656        202990
+```
+
+As you can see, it applies filter to the benchmarks, both when running the benchmark, and before doing the diff. And to make the diff work, the matches are replaced with some common string. Thus, you can compare two different benchmark families within one benchmark binary.
+As you can note, the values in `Time` and `CPU` columns are calculated as `(new - old) / |old|`.
+
+3. Compare filter one from benchmark one to filter two from benchmark two:
+The program is invoked like:
+
+``` bash
+$ compare.py filters <benchmark_baseline> <filter_baseline> <benchmark_contender> <filter_contender> [benchmark options]...
+```
+
+Where `<benchmark_baseline>` and `<benchmark_contender>` either specify a benchmark executable file, or a JSON output file. The type of the input file is automatically detected. If a benchmark executable is specified then the benchmark is run to obtain the results. Otherwise the results are simply loaded from the output file.
+
+Where `<filter_baseline>` and `<filter_contender>` are the same regex filters that you would pass to the `[--benchmark_filter=<regex>]` parameter of the benchmark binary.
+
+`[benchmark options]` will be passed to the benchmarks invocations. They can be anything that binary accepts, be it either normal `--benchmark_*` parameters, or some custom parameters your binary takes.
+
+Example output:
+```
+$ ./compare.py benchmarksfiltered ./a.out BM_memcpy ./a.out BM_copy
+RUNNING: ./a.out --benchmark_filter=BM_memcpy --benchmark_out=/tmp/tmp_FvbYg
+Run on (8 X 4000 MHz CPU s)
+2017-11-07 21:38:27
+------------------------------------------------------
+Benchmark               Time           CPU Iterations
+------------------------------------------------------
+BM_memcpy/8            37 ns         37 ns   18953482   204.118MB/s
+BM_memcpy/64           74 ns         74 ns    9206578   828.245MB/s
+BM_memcpy/512          91 ns         91 ns    8086195   5.25476GB/s
+BM_memcpy/1024        120 ns        120 ns    5804513   7.95662GB/s
+BM_memcpy/8192        664 ns        664 ns    1028363   11.4948GB/s
+RUNNING: ./a.out --benchmark_filter=BM_copy --benchmark_out=/tmp/tmpDfL5iE
+Run on (8 X 4000 MHz CPU s)
+2017-11-07 21:38:32
+----------------------------------------------------
+Benchmark             Time           CPU Iterations
+----------------------------------------------------
+BM_copy/8           230 ns        230 ns    2985909   33.1161MB/s
+BM_copy/64         1654 ns       1653 ns     419408   36.9137MB/s
+BM_copy/512       13122 ns      13120 ns      53403   37.2156MB/s
+BM_copy/1024      26679 ns      26666 ns      26575   36.6218MB/s
+BM_copy/8192     215068 ns     215053 ns       3221   36.3283MB/s
+Comparing BM_memcpy (from ./a.out) to BM_copy (from ./a.out)
+Benchmark                               Time             CPU      Time Old      Time New       CPU Old       CPU New
+--------------------------------------------------------------------------------------------------------------------
+[BM_memcpy vs. BM_copy]/8            +5.1649         +5.1637            37           230            37           230
+[BM_memcpy vs. BM_copy]/64          +21.4352        +21.4374            74          1654            74          1653
+[BM_memcpy vs. BM_copy]/512        +143.6022       +143.5865            91         13122            91         13120
+[BM_memcpy vs. BM_copy]/1024       +221.5903       +221.4790           120         26679           120         26666
+[BM_memcpy vs. BM_copy]/8192       +322.9059       +323.0096           664        215068           664        215053
+```
+This is a mix of the previous two modes, two (potentially different) benchmark binaries are run, and a different filter is applied to each one.
+As you can note, the values in `Time` and `CPU` columns are calculated as `(new - old) / |old|`.
+
+### Note: Interpreting the output
+
+Performance measurements are an art, and performance comparisons are doubly so.
+Results are often noisy and don't necessarily have large absolute differences to
+them, so just by visual inspection, it is not at all apparent if two
+measurements are actually showing a performance change or not. It is even more
+confusing with multiple benchmark repetitions.
+
+Thankfully, what we can do, is use statistical tests on the results to determine
+whether the performance has statistically-significantly changed. `compare.py`
+uses [Mann–Whitney U
+test](https://en.wikipedia.org/wiki/Mann%E2%80%93Whitney_U_test), with a null
+hypothesis being that there's no difference in performance.
+ 
+**The below output is a summary of a benchmark comparison with statistics
+provided for a multi-threaded process.**
+```
+Benchmark                                               Time        CPU    Time Old      Time New       CPU Old       CPU New
+-----------------------------------------------------------------------------------------------------------------------------
+benchmark/threads:1/process_time/real_time_pvalue     0.0000     0.0000    U Test, Repetitions: 27 vs 27
+benchmark/threads:1/process_time/real_time_mean      -0.1442    -0.1442          90            77            90            77
+benchmark/threads:1/process_time/real_time_median    -0.1444    -0.1444          90            77            90            77
+benchmark/threads:1/process_time/real_time_stddev    +0.3974    +0.3933           0             0             0             0
+benchmark/threads:1/process_time/real_time_cv        +0.6329    +0.6280           0             0             0             0
+OVERALL_GEOMEAN                                      -0.1442    -0.1442           0             0             0             0
+```
+--------------------------------------------
+Here's a breakdown of each row:
+
+**benchmark/threads:1/process_time/real_time_pvalue**: This shows the _p-value_ for
+the statistical test comparing the performance of the process running with one
+thread. A value of 0.0000 suggests a statistically significant difference in
+performance. The comparison was conducted using the U Test (Mann-Whitney
+U Test) with 27 repetitions for each case.
+
+**benchmark/threads:1/process_time/real_time_mean**: This shows the relative
+difference in mean execution time between two different cases. The negative
+value (-0.1442) implies that the new process is faster by about 14.42%. The old
+time was 90 units, while the new time is 77 units.
+
+**benchmark/threads:1/process_time/real_time_median**: Similarly, this shows the
+relative difference in the median execution time. Again, the new process is
+faster by 14.44%.
+
+**benchmark/threads:1/process_time/real_time_stddev**: This is the relative
+difference in the standard deviation of the execution time, which is a measure
+of how much variation or dispersion there is from the mean. A positive value
+(+0.3974) implies there is more variance in the execution time in the new
+process.
+
+**benchmark/threads:1/process_time/real_time_cv**: CV stands for Coefficient of
+Variation. It is the ratio of the standard deviation to the mean. It provides a
+standardized measure of dispersion. An increase (+0.6329) indicates more
+relative variability in the new process.
+
+**OVERALL_GEOMEAN**: Geomean stands for geometric mean, a type of average that is
+less influenced by outliers. The negative value indicates a general improvement
+in the new process. However, given the values are all zero for the old and new
+times, this seems to be a mistake or placeholder in the output.
+
+-----------------------------------------
+
+
+
+Let's first try to see what the different columns represent in the above
+`compare.py` benchmarking output:
+
+  1. **Benchmark:** The name of the function being benchmarked, along with the
+     size of the input (after the slash).
+
+  2. **Time:** The average time per operation, across all iterations.
+
+  3. **CPU:** The average CPU time per operation, across all iterations.
+
+  4. **Iterations:** The number of iterations the benchmark was run to get a
+     stable estimate.
+
+  5. **Time Old and Time New:** These represent the average time it takes for a
+     function to run in two different scenarios or versions. For example, you
+     might be comparing how fast a function runs before and after you make some
+     changes to it.
+
+  6. **CPU Old and CPU New:** These show the average amount of CPU time that the
+     function uses in two different scenarios or versions. This is similar to
+     Time Old and Time New, but focuses on CPU usage instead of overall time.
+
+In the comparison section, the relative differences in both time and CPU time
+are displayed for each input size.
+
+
+A statistically-significant difference is determined by a **p-value**, which is
+a measure of the probability that the observed difference could have occurred
+just by random chance. A smaller p-value indicates stronger evidence against the
+null hypothesis. 
+
+**Therefore:**
+  1. If the p-value is less than the chosen significance level (alpha), we
+     reject the null hypothesis and conclude the benchmarks are significantly
+     different.
+  2. If the p-value is greater than or equal to alpha, we fail to reject the
+     null hypothesis and treat the two benchmarks as similar.
+
+
+
+The result of said the statistical test is additionally communicated through color coding:
+```diff
++ Green:
+```
+  The benchmarks are _**statistically different**_. This could mean the
+  performance has either **significantly improved** or **significantly
+  deteriorated**. You should look at the actual performance numbers to see which
+  is the case.
+```diff
+- Red:
+```
+  The benchmarks are _**statistically similar**_. This means the performance
+  **hasn't significantly changed**.
+
+In statistical terms, **'green'** means we reject the null hypothesis that
+there's no difference in performance, and **'red'** means we fail to reject the
+null hypothesis. This might seem counter-intuitive if you're expecting 'green'
+to mean 'improved performance' and 'red' to mean 'worsened performance'. 
+```bash
+  But remember, in this context:
+
+    'Success' means 'successfully finding a difference'.
+    'Failure' means 'failing to find a difference'.
+```
+
+
+Also, please note that **even if** we determine that there **is** a
+statistically-significant difference between the two measurements, it does not
+_necessarily_ mean that the actual benchmarks that were measured **are**
+different, or vice versa, even if we determine that there is **no**
+statistically-significant difference between the two measurements, it does not
+necessarily mean that the actual benchmarks that were measured **are not**
+different.
+
+
+
+### U test
+
+If there is a sufficient repetition count of the benchmarks, the tool can do
+a [U Test](https://en.wikipedia.org/wiki/Mann%E2%80%93Whitney_U_test), of the
+null hypothesis that it is equally likely that a randomly selected value from
+one sample will be less than or greater than a randomly selected value from a
+second sample.
+
+If the calculated p-value is below this value is lower than the significance
+level alpha, then the result is said to be statistically significant and the
+null hypothesis is rejected. Which in other words means that the two benchmarks
+aren't identical.
+
+**WARNING**: requires **LARGE** (no less than 9) number of repetitions to be
+meaningful!

third_party/benchmark/include/benchmark/export.h

@@ -0,0 +1,47 @@
+#ifndef BENCHMARK_EXPORT_H
+#define BENCHMARK_EXPORT_H
+
+#if defined(_WIN32)
+#define EXPORT_ATTR __declspec(dllexport)
+#define IMPORT_ATTR __declspec(dllimport)
+#define NO_EXPORT_ATTR
+#define DEPRECATED_ATTR __declspec(deprecated)
+#else  // _WIN32
+#define EXPORT_ATTR __attribute__((visibility("default")))
+#define IMPORT_ATTR __attribute__((visibility("default")))
+#define NO_EXPORT_ATTR __attribute__((visibility("hidden")))
+#define DEPRECATE_ATTR __attribute__((__deprecated__))
+#endif  // _WIN32
+
+#ifdef BENCHMARK_STATIC_DEFINE
+#define BENCHMARK_EXPORT
+#define BENCHMARK_NO_EXPORT
+#else  // BENCHMARK_STATIC_DEFINE
+#ifndef BENCHMARK_EXPORT
+#ifdef benchmark_EXPORTS
+/* We are building this library */
+#define BENCHMARK_EXPORT EXPORT_ATTR
+#else  // benchmark_EXPORTS
+/* We are using this library */
+#define BENCHMARK_EXPORT IMPORT_ATTR
+#endif  // benchmark_EXPORTS
+#endif  // !BENCHMARK_EXPORT
+
+#ifndef BENCHMARK_NO_EXPORT
+#define BENCHMARK_NO_EXPORT NO_EXPORT_ATTR
+#endif  // !BENCHMARK_NO_EXPORT
+#endif  // BENCHMARK_STATIC_DEFINE
+
+#ifndef BENCHMARK_DEPRECATED
+#define BENCHMARK_DEPRECATED DEPRECATE_ATTR
+#endif  // BENCHMARK_DEPRECATED
+
+#ifndef BENCHMARK_DEPRECATED_EXPORT
+#define BENCHMARK_DEPRECATED_EXPORT BENCHMARK_EXPORT BENCHMARK_DEPRECATED
+#endif  // BENCHMARK_DEPRECATED_EXPORT
+
+#ifndef BENCHMARK_DEPRECATED_NO_EXPORT
+#define BENCHMARK_DEPRECATED_NO_EXPORT BENCHMARK_NO_EXPORT BENCHMARK_DEPRECATED
+#endif  // BENCHMARK_DEPRECATED_EXPORT
+
+#endif /* BENCHMARK_EXPORT_H */

third_party/benchmark/pyproject.toml

@@ -0,0 +1,86 @@
+[build-system]
+requires = ["setuptools", "setuptools-scm[toml]", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "google_benchmark"
+description = "A library to benchmark code snippets."
+requires-python = ">=3.8"
+license = {file = "LICENSE"}
+keywords = ["benchmark"]
+
+authors = [
+    {name = "Google", email = "benchmark-discuss@googlegroups.com"},
+]
+
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Intended Audience :: Developers",
+    "Intended Audience :: Science/Research",
+    "License :: OSI Approved :: Apache Software License",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Topic :: Software Development :: Testing",
+    "Topic :: System :: Benchmark",
+]
+
+dynamic = ["readme", "version"]
+
+dependencies = [
+    "absl-py>=0.7.1",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pre-commit>=3.3.3",
+]
+
+[project.urls]
+Homepage = "https://github.com/google/benchmark"
+Documentation = "https://github.com/google/benchmark/tree/main/docs"
+Repository = "https://github.com/google/benchmark.git"
+Discord = "https://discord.gg/cz7UX7wKC2"
+
+[tool.setuptools]
+package-dir = {"" = "bindings/python"}
+zip-safe = false
+
+[tool.setuptools.packages.find]
+where = ["bindings/python"]
+
+[tool.setuptools.dynamic]
+readme = { file = "README.md", content-type = "text/markdown" }
+
+[tool.setuptools_scm]
+
+[tool.mypy]
+check_untyped_defs = true
+disallow_incomplete_defs = true
+pretty = true
+python_version = "3.11"
+strict_optional = false
+warn_unreachable = true
+
+[[tool.mypy.overrides]]
+module = ["yaml"]
+ignore_missing_imports = true
+
+[tool.ruff]
+# explicitly tell ruff the source directory to correctly identify first-party package.
+src = ["bindings/python"]
+
+line-length = 80
+target-version = "py311"
+
+[tool.ruff.lint]
+# Enable pycodestyle (`E`, `W`), Pyflakes (`F`), and isort (`I`) codes by default.
+select = ["E", "F", "I", "W"]
+ignore = [
+    "E501", # line too long
+]
+
+[tool.ruff.lint.isort]
+combine-as-imports = true

third_party/benchmark/setup.py

@@ -0,0 +1,148 @@
+import contextlib
+import os
+import platform
+import re
+import shutil
+from pathlib import Path
+from typing import Any, Generator
+
+import setuptools
+from setuptools.command import build_ext
+
+IS_WINDOWS = platform.system() == "Windows"
+IS_MAC = platform.system() == "Darwin"
+IS_LINUX = platform.system() == "Linux"
+
+# hardcoded SABI-related options. Requires that each Python interpreter
+# (hermetic or not) participating is of the same major-minor version.
+version_tuple = tuple(int(i) for i in platform.python_version_tuple())
+py_limited_api = version_tuple >= (3, 12)
+options = {"bdist_wheel": {"py_limited_api": "cp312"}} if py_limited_api else {}
+
+
+def is_cibuildwheel() -> bool:
+    return os.getenv("CIBUILDWHEEL") is not None
+
+
+@contextlib.contextmanager
+def _maybe_patch_toolchains() -> Generator[None, None, None]:
+    """
+    Patch rules_python toolchains to ignore root user error
+    when run in a Docker container on Linux in cibuildwheel.
+    """
+
+    def fmt_toolchain_args(matchobj):
+        suffix = "ignore_root_user_error = True"
+        callargs = matchobj.group(1)
+        # toolchain def is broken over multiple lines
+        if callargs.endswith("\n"):
+            callargs = callargs + "    " + suffix + ",\n"
+        # toolchain def is on one line.
+        else:
+            callargs = callargs + ", " + suffix
+        return "python.toolchain(" + callargs + ")"
+
+    CIBW_LINUX = is_cibuildwheel() and IS_LINUX
+    try:
+        if CIBW_LINUX:
+            module_bazel = Path("MODULE.bazel")
+            content: str = module_bazel.read_text()
+            module_bazel.write_text(
+                re.sub(
+                    r"python.toolchain\(([\w\"\s,.=]*)\)",
+                    fmt_toolchain_args,
+                    content,
+                )
+            )
+        yield
+    finally:
+        if CIBW_LINUX:
+            module_bazel.write_text(content)
+
+
+class BazelExtension(setuptools.Extension):
+    """A C/C++ extension that is defined as a Bazel BUILD target."""
+
+    def __init__(self, name: str, bazel_target: str, **kwargs: Any):
+        super().__init__(name=name, sources=[], **kwargs)
+
+        self.bazel_target = bazel_target
+        stripped_target = bazel_target.split("//")[-1]
+        self.relpath, self.target_name = stripped_target.split(":")
+
+
+class BuildBazelExtension(build_ext.build_ext):
+    """A command that runs Bazel to build a C/C++ extension."""
+
+    def run(self):
+        for ext in self.extensions:
+            self.bazel_build(ext)
+        super().run()
+        # explicitly call `bazel shutdown` for graceful exit
+        self.spawn(["bazel", "shutdown"])
+
+    def copy_extensions_to_source(self):
+        """
+        Copy generated extensions into the source tree.
+        This is done in the ``bazel_build`` method, so it's not necessary to
+        do again in the `build_ext` base class.
+        """
+        pass
+
+    def bazel_build(self, ext: BazelExtension) -> None:
+        """Runs the bazel build to create the package."""
+        temp_path = Path(self.build_temp)
+        # omit the patch version to avoid build errors if the toolchain is not
+        # yet registered in the current @rules_python version.
+        # patch version differences should be fine.
+        python_version = ".".join(platform.python_version_tuple()[:2])
+
+        bazel_argv = [
+            "bazel",
+            "build",
+            ext.bazel_target,
+            f"--symlink_prefix={temp_path / 'bazel-'}",
+            f"--compilation_mode={'dbg' if self.debug else 'opt'}",
+            # C++17 is required by nanobind
+            f"--cxxopt={'/std:c++17' if IS_WINDOWS else '-std=c++17'}",
+            f"--@rules_python//python/config_settings:python_version={python_version}",
+        ]
+
+        if ext.py_limited_api:
+            bazel_argv += ["--@nanobind_bazel//:py-limited-api=cp312"]
+
+        if IS_WINDOWS:
+            # Link with python*.lib.
+            for library_dir in self.library_dirs:
+                bazel_argv.append("--linkopt=/LIBPATH:" + library_dir)
+        elif IS_MAC:
+            # C++17 needs macOS 10.14 at minimum
+            bazel_argv.append("--macos_minimum_os=10.14")
+
+        with _maybe_patch_toolchains():
+            self.spawn(bazel_argv)
+
+        if IS_WINDOWS:
+            suffix = ".pyd"
+        else:
+            suffix = ".abi3.so" if ext.py_limited_api else ".so"
+
+        ext_name = ext.target_name + suffix
+        ext_bazel_bin_path = temp_path / "bazel-bin" / ext.relpath / ext_name
+        ext_dest_path = Path(self.get_ext_fullpath(ext.name)).with_name(
+            ext_name
+        )
+        shutil.copyfile(ext_bazel_bin_path, ext_dest_path)
+
+
+setuptools.setup(
+    cmdclass=dict(build_ext=BuildBazelExtension),
+    ext_modules=[
+        BazelExtension(
+            name="google_benchmark._benchmark",
+            bazel_target="//bindings/python/google_benchmark:_benchmark",
+            py_limited_api=py_limited_api,
+        )
+    ],
+    options=options,
+)

third_party/benchmark/src/CMakeLists.txt

@@ -0,0 +1,179 @@
+# Allow the source files to find headers in src/
+include(GNUInstallDirs)
+include_directories(${PROJECT_SOURCE_DIR}/src)
+
+if (DEFINED BENCHMARK_CXX_LINKER_FLAGS)
+  list(APPEND CMAKE_SHARED_LINKER_FLAGS ${BENCHMARK_CXX_LINKER_FLAGS})
+  list(APPEND CMAKE_MODULE_LINKER_FLAGS ${BENCHMARK_CXX_LINKER_FLAGS})
+endif()
+
+file(GLOB
+  SOURCE_FILES
+    *.cc
+    ${PROJECT_SOURCE_DIR}/include/benchmark/*.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/*.h)
+file(GLOB BENCHMARK_MAIN "benchmark_main.cc")
+foreach(item ${BENCHMARK_MAIN})
+  list(REMOVE_ITEM SOURCE_FILES "${item}")
+endforeach()
+
+add_library(benchmark ${SOURCE_FILES})
+add_library(benchmark::benchmark ALIAS benchmark)
+set_target_properties(benchmark PROPERTIES
+  OUTPUT_NAME "benchmark"
+  VERSION ${GENERIC_LIB_VERSION}
+  SOVERSION ${GENERIC_LIB_SOVERSION}
+)
+target_include_directories(benchmark PUBLIC
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+)
+
+set_property(
+  SOURCE benchmark.cc
+  APPEND
+  PROPERTY COMPILE_DEFINITIONS
+  BENCHMARK_VERSION="${VERSION}"
+)
+
+# libpfm, if available
+if (PFM_FOUND)
+  target_link_libraries(benchmark PRIVATE PFM::libpfm)
+  target_compile_definitions(benchmark PRIVATE -DHAVE_LIBPFM)
+endif()
+
+# pthread affinity, if available
+if(HAVE_PTHREAD_AFFINITY)
+  target_compile_definitions(benchmark PRIVATE -DBENCHMARK_HAS_PTHREAD_AFFINITY)
+endif()
+
+# Link threads.
+target_link_libraries(benchmark PRIVATE Threads::Threads)
+
+target_link_libraries(benchmark PRIVATE ${BENCHMARK_CXX_LIBRARIES})
+
+if(HAVE_LIB_RT)
+  target_link_libraries(benchmark PRIVATE rt)
+endif(HAVE_LIB_RT)
+
+
+# We need extra libraries on Windows
+if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
+  target_link_libraries(benchmark PRIVATE shlwapi)
+endif()
+
+# We need extra libraries on Solaris
+if(${CMAKE_SYSTEM_NAME} MATCHES "SunOS")
+  target_link_libraries(benchmark PRIVATE kstat)
+endif()
+
+if (NOT BUILD_SHARED_LIBS)
+  target_compile_definitions(benchmark PUBLIC -DBENCHMARK_STATIC_DEFINE)
+endif()
+
+# Benchmark main library
+add_library(benchmark_main "benchmark_main.cc")
+add_library(benchmark::benchmark_main ALIAS benchmark_main)
+set_target_properties(benchmark_main PROPERTIES
+  OUTPUT_NAME "benchmark_main"
+  VERSION ${GENERIC_LIB_VERSION}
+  SOVERSION ${GENERIC_LIB_SOVERSION}
+  DEFINE_SYMBOL benchmark_EXPORTS
+)
+target_link_libraries(benchmark_main PUBLIC benchmark::benchmark)
+
+set(generated_dir "${PROJECT_BINARY_DIR}")
+
+set(version_config "${generated_dir}/${PROJECT_NAME}ConfigVersion.cmake")
+set(project_config "${generated_dir}/${PROJECT_NAME}Config.cmake")
+set(pkg_config "${generated_dir}/${PROJECT_NAME}.pc")
+set(pkg_config_main "${generated_dir}/${PROJECT_NAME}_main.pc")
+set(targets_to_export benchmark benchmark_main)
+set(targets_export_name "${PROJECT_NAME}Targets")
+
+set(namespace "${PROJECT_NAME}::")
+
+include(CMakePackageConfigHelpers)
+
+configure_package_config_file (
+  ${PROJECT_SOURCE_DIR}/cmake/Config.cmake.in
+  ${project_config}
+  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
+  NO_SET_AND_CHECK_MACRO
+  NO_CHECK_REQUIRED_COMPONENTS_MACRO
+)
+write_basic_package_version_file(
+  "${version_config}" VERSION ${GENERIC_LIB_VERSION} COMPATIBILITY SameMajorVersion
+)
+
+configure_file("${PROJECT_SOURCE_DIR}/cmake/benchmark.pc.in" "${pkg_config}" @ONLY)
+configure_file("${PROJECT_SOURCE_DIR}/cmake/benchmark_main.pc.in" "${pkg_config_main}" @ONLY)
+
+export (
+  TARGETS ${targets_to_export}
+  NAMESPACE "${namespace}"
+  FILE ${generated_dir}/${targets_export_name}.cmake
+)
+
+if (BENCHMARK_ENABLE_INSTALL)
+  # Install target (will install the library to specified CMAKE_INSTALL_PREFIX variable)
+  install(
+    TARGETS ${targets_to_export}
+    EXPORT ${targets_export_name}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+    INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+
+  install(
+    DIRECTORY "${PROJECT_SOURCE_DIR}/include/benchmark"
+              "${PROJECT_BINARY_DIR}/include/benchmark"
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+    FILES_MATCHING PATTERN "*.*h")
+
+  install(
+      FILES "${project_config}" "${version_config}"
+      DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}")
+
+  install(
+      FILES "${pkg_config}" "${pkg_config_main}"
+      DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
+
+  install(
+      EXPORT "${targets_export_name}"
+      NAMESPACE "${namespace}"
+      DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}")
+endif()
+
+if (BENCHMARK_ENABLE_DOXYGEN)
+  find_package(Doxygen REQUIRED)
+  set(DOXYGEN_QUIET YES)
+  set(DOXYGEN_RECURSIVE YES)
+  set(DOXYGEN_GENERATE_HTML YES)
+  set(DOXYGEN_GENERATE_MAN NO)
+  set(DOXYGEN_MARKDOWN_SUPPORT YES)
+  set(DOXYGEN_BUILTIN_STL_SUPPORT YES)
+  set(DOXYGEN_EXTRACT_PACKAGE YES)
+  set(DOXYGEN_EXTRACT_STATIC YES)
+  set(DOXYGEN_SHOW_INCLUDE_FILES YES)
+  set(DOXYGEN_BINARY_TOC YES)
+  set(DOXYGEN_TOC_EXPAND YES)
+  set(DOXYGEN_USE_MDFILE_AS_MAINPAGE "index.md")
+  doxygen_add_docs(benchmark_doxygen
+    docs
+    include
+    src
+    ALL
+    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+    COMMENT "Building documentation with Doxygen.")
+  if (BENCHMARK_ENABLE_INSTALL AND BENCHMARK_INSTALL_DOCS)
+    install(
+      DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/html/"
+      DESTINATION ${CMAKE_INSTALL_DOCDIR})
+  endif()
+else()
+  if (BENCHMARK_ENABLE_INSTALL AND BENCHMARK_INSTALL_DOCS)
+    install(
+      DIRECTORY "${PROJECT_SOURCE_DIR}/docs/"
+      DESTINATION ${CMAKE_INSTALL_DOCDIR})
+  endif()
+endif()

third_party/benchmark/src/arraysize.h

@@ -0,0 +1,33 @@
+#ifndef BENCHMARK_ARRAYSIZE_H_
+#define BENCHMARK_ARRAYSIZE_H_
+
+#include "internal_macros.h"
+
+namespace benchmark {
+namespace internal {
+// The arraysize(arr) macro returns the # of elements in an array arr.
+// The expression is a compile-time constant, and therefore can be
+// used in defining new arrays, for example.  If you use arraysize on
+// a pointer by mistake, you will get a compile-time error.
+//
+
+// This template function declaration is used in defining arraysize.
+// Note that the function doesn't need an implementation, as we only
+// use its type.
+template <typename T, size_t N>
+char (&ArraySizeHelper(T (&array)[N]))[N];
+
+// That gcc wants both of these prototypes seems mysterious. VC, for
+// its part, can't decide which to use (another mystery). Matching of
+// template overloads: the final frontier.
+#ifndef COMPILER_MSVC
+template <typename T, size_t N>
+char (&ArraySizeHelper(const T (&array)[N]))[N];
+#endif
+
+#define arraysize(array) (sizeof(::benchmark::internal::ArraySizeHelper(array)))
+
+}  // end namespace internal
+}  // end namespace benchmark
+
+#endif  // BENCHMARK_ARRAYSIZE_H_

third_party/benchmark/src/benchmark.cc

@@ -0,0 +1,808 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "benchmark/benchmark.h"
+
+#include "benchmark_api_internal.h"
+#include "benchmark_runner.h"
+#include "internal_macros.h"
+
+#ifndef BENCHMARK_OS_WINDOWS
+#if !defined(BENCHMARK_OS_FUCHSIA) && !defined(BENCHMARK_OS_QURT)
+#include <sys/resource.h>
+#endif
+#include <sys/time.h>
+#include <unistd.h>
+#endif
+
+#include <algorithm>
+#include <atomic>
+#include <condition_variable>
+#include <cstdio>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <limits>
+#include <map>
+#include <memory>
+#include <random>
+#include <string>
+#include <thread>
+#include <utility>
+
+#include "check.h"
+#include "colorprint.h"
+#include "commandlineflags.h"
+#include "complexity.h"
+#include "counter.h"
+#include "internal_macros.h"
+#include "log.h"
+#include "mutex.h"
+#include "perf_counters.h"
+#include "re.h"
+#include "statistics.h"
+#include "string_util.h"
+#include "thread_manager.h"
+#include "thread_timer.h"
+
+namespace benchmark {
+// Print a list of benchmarks. This option overrides all other options.
+BM_DEFINE_bool(benchmark_list_tests, false);
+
+// A regular expression that specifies the set of benchmarks to execute.  If
+// this flag is empty, or if this flag is the string \"all\", all benchmarks
+// linked into the binary are run.
+BM_DEFINE_string(benchmark_filter, "");
+
+// Specification of how long to run the benchmark.
+//
+// It can be either an exact number of iterations (specified as `<integer>x`),
+// or a minimum number of seconds (specified as `<float>s`). If the latter
+// format (ie., min seconds) is used, the system may run the benchmark longer
+// until the results are considered significant.
+//
+// For backward compatibility, the `s` suffix may be omitted, in which case,
+// the specified number is interpreted as the number of seconds.
+//
+// For cpu-time based tests, this is the lower bound
+// on the total cpu time used by all threads that make up the test.  For
+// real-time based tests, this is the lower bound on the elapsed time of the
+// benchmark execution, regardless of number of threads.
+BM_DEFINE_string(benchmark_min_time, kDefaultMinTimeStr);
+
+// Minimum number of seconds a benchmark should be run before results should be
+// taken into account. This e.g can be necessary for benchmarks of code which
+// needs to fill some form of cache before performance is of interest.
+// Note: results gathered within this period are discarded and not used for
+// reported result.
+BM_DEFINE_double(benchmark_min_warmup_time, 0.0);
+
+// The number of runs of each benchmark. If greater than 1, the mean and
+// standard deviation of the runs will be reported.
+BM_DEFINE_int32(benchmark_repetitions, 1);
+
+// If set, enable random interleaving of repetitions of all benchmarks.
+// See http://github.com/google/benchmark/issues/1051 for details.
+BM_DEFINE_bool(benchmark_enable_random_interleaving, false);
+
+// Report the result of each benchmark repetitions. When 'true' is specified
+// only the mean, standard deviation, and other statistics are reported for
+// repeated benchmarks. Affects all reporters.
+BM_DEFINE_bool(benchmark_report_aggregates_only, false);
+
+// Display the result of each benchmark repetitions. When 'true' is specified
+// only the mean, standard deviation, and other statistics are displayed for
+// repeated benchmarks. Unlike benchmark_report_aggregates_only, only affects
+// the display reporter, but  *NOT* file reporter, which will still contain
+// all the output.
+BM_DEFINE_bool(benchmark_display_aggregates_only, false);
+
+// The format to use for console output.
+// Valid values are 'console', 'json', or 'csv'.
+BM_DEFINE_string(benchmark_format, "console");
+
+// The format to use for file output.
+// Valid values are 'console', 'json', or 'csv'.
+BM_DEFINE_string(benchmark_out_format, "json");
+
+// The file to write additional output to.
+BM_DEFINE_string(benchmark_out, "");
+
+// Whether to use colors in the output.  Valid values:
+// 'true'/'yes'/1, 'false'/'no'/0, and 'auto'. 'auto' means to use colors if
+// the output is being sent to a terminal and the TERM environment variable is
+// set to a terminal type that supports colors.
+BM_DEFINE_string(benchmark_color, "auto");
+
+// Whether to use tabular format when printing user counters to the console.
+// Valid values: 'true'/'yes'/1, 'false'/'no'/0.  Defaults to false.
+BM_DEFINE_bool(benchmark_counters_tabular, false);
+
+// List of additional perf counters to collect, in libpfm format. For more
+// information about libpfm: https://man7.org/linux/man-pages/man3/libpfm.3.html
+BM_DEFINE_string(benchmark_perf_counters, "");
+
+// Extra context to include in the output formatted as comma-separated key-value
+// pairs. Kept internal as it's only used for parsing from env/command line.
+BM_DEFINE_kvpairs(benchmark_context, {});
+
+// Set the default time unit to use for reports
+// Valid values are 'ns', 'us', 'ms' or 's'
+BM_DEFINE_string(benchmark_time_unit, "");
+
+// The level of verbose logging to output
+BM_DEFINE_int32(v, 0);
+
+namespace internal {
+
+std::map<std::string, std::string>* global_context = nullptr;
+
+BENCHMARK_EXPORT std::map<std::string, std::string>*& GetGlobalContext() {
+  return global_context;
+}
+
+static void const volatile* volatile global_force_escape_pointer;
+
+// FIXME: Verify if LTO still messes this up?
+void UseCharPointer(char const volatile* const v) {
+  // We want to escape the pointer `v` so that the compiler can not eliminate
+  // computations that produced it. To do that, we escape the pointer by storing
+  // it into a volatile variable, since generally, volatile store, is not
+  // something the compiler is allowed to elide.
+  global_force_escape_pointer = reinterpret_cast<void const volatile*>(v);
+}
+
+}  // namespace internal
+
+State::State(std::string name, IterationCount max_iters,
+             const std::vector<int64_t>& ranges, int thread_i, int n_threads,
+             internal::ThreadTimer* timer, internal::ThreadManager* manager,
+             internal::PerfCountersMeasurement* perf_counters_measurement)
+    : total_iterations_(0),
+      batch_leftover_(0),
+      max_iterations(max_iters),
+      started_(false),
+      finished_(false),
+      skipped_(internal::NotSkipped),
+      range_(ranges),
+      complexity_n_(0),
+      name_(std::move(name)),
+      thread_index_(thread_i),
+      threads_(n_threads),
+      timer_(timer),
+      manager_(manager),
+      perf_counters_measurement_(perf_counters_measurement) {
+  BM_CHECK(max_iterations != 0) << "At least one iteration must be run";
+  BM_CHECK_LT(thread_index_, threads_)
+      << "thread_index must be less than threads";
+
+  // Add counters with correct flag now.  If added with `counters[name]` in
+  // `PauseTiming`, a new `Counter` will be inserted the first time, which
+  // won't have the flag.  Inserting them now also reduces the allocations
+  // during the benchmark.
+  if (perf_counters_measurement_) {
+    for (const std::string& counter_name :
+         perf_counters_measurement_->names()) {
+      counters[counter_name] = Counter(0.0, Counter::kAvgIterations);
+    }
+  }
+
+  // Note: The use of offsetof below is technically undefined until C++17
+  // because State is not a standard layout type. However, all compilers
+  // currently provide well-defined behavior as an extension (which is
+  // demonstrated since constexpr evaluation must diagnose all undefined
+  // behavior). However, GCC and Clang also warn about this use of offsetof,
+  // which must be suppressed.
+#if defined(__INTEL_COMPILER)
+#pragma warning push
+#pragma warning(disable : 1875)
+#elif defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winvalid-offsetof"
+#endif
+#if defined(__NVCC__)
+#pragma nv_diagnostic push
+#pragma nv_diag_suppress 1427
+#endif
+#if defined(__NVCOMPILER)
+#pragma diagnostic push
+#pragma diag_suppress offset_in_non_POD_nonstandard
+#endif
+  // Offset tests to ensure commonly accessed data is on the first cache line.
+  const int cache_line_size = 64;
+  static_assert(
+      offsetof(State, skipped_) <= (cache_line_size - sizeof(skipped_)), "");
+#if defined(__INTEL_COMPILER)
+#pragma warning pop
+#elif defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+#if defined(__NVCC__)
+#pragma nv_diagnostic pop
+#endif
+#if defined(__NVCOMPILER)
+#pragma diagnostic pop
+#endif
+}
+
+void State::PauseTiming() {
+  // Add in time accumulated so far
+  BM_CHECK(started_ && !finished_ && !skipped());
+  timer_->StopTimer();
+  if (perf_counters_measurement_) {
+    std::vector<std::pair<std::string, double>> measurements;
+    if (!perf_counters_measurement_->Stop(measurements)) {
+      BM_CHECK(false) << "Perf counters read the value failed.";
+    }
+    for (const auto& name_and_measurement : measurements) {
+      const std::string& name = name_and_measurement.first;
+      const double measurement = name_and_measurement.second;
+      // Counter was inserted with `kAvgIterations` flag by the constructor.
+      assert(counters.find(name) != counters.end());
+      counters[name].value += measurement;
+    }
+  }
+}
+
+void State::ResumeTiming() {
+  BM_CHECK(started_ && !finished_ && !skipped());
+  timer_->StartTimer();
+  if (perf_counters_measurement_) {
+    perf_counters_measurement_->Start();
+  }
+}
+
+void State::SkipWithMessage(const std::string& msg) {
+  skipped_ = internal::SkippedWithMessage;
+  {
+    MutexLock l(manager_->GetBenchmarkMutex());
+    if (internal::NotSkipped == manager_->results.skipped_) {
+      manager_->results.skip_message_ = msg;
+      manager_->results.skipped_ = skipped_;
+    }
+  }
+  total_iterations_ = 0;
+  if (timer_->running()) timer_->StopTimer();
+}
+
+void State::SkipWithError(const std::string& msg) {
+  skipped_ = internal::SkippedWithError;
+  {
+    MutexLock l(manager_->GetBenchmarkMutex());
+    if (internal::NotSkipped == manager_->results.skipped_) {
+      manager_->results.skip_message_ = msg;
+      manager_->results.skipped_ = skipped_;
+    }
+  }
+  total_iterations_ = 0;
+  if (timer_->running()) timer_->StopTimer();
+}
+
+void State::SetIterationTime(double seconds) {
+  timer_->SetIterationTime(seconds);
+}
+
+void State::SetLabel(const std::string& label) {
+  MutexLock l(manager_->GetBenchmarkMutex());
+  manager_->results.report_label_ = label;
+}
+
+void State::StartKeepRunning() {
+  BM_CHECK(!started_ && !finished_);
+  started_ = true;
+  total_iterations_ = skipped() ? 0 : max_iterations;
+  manager_->StartStopBarrier();
+  if (!skipped()) ResumeTiming();
+}
+
+void State::FinishKeepRunning() {
+  BM_CHECK(started_ && (!finished_ || skipped()));
+  if (!skipped()) {
+    PauseTiming();
+  }
+  // Total iterations has now wrapped around past 0. Fix this.
+  total_iterations_ = 0;
+  finished_ = true;
+  manager_->StartStopBarrier();
+}
+
+namespace internal {
+namespace {
+
+// Flushes streams after invoking reporter methods that write to them. This
+// ensures users get timely updates even when streams are not line-buffered.
+void FlushStreams(BenchmarkReporter* reporter) {
+  if (!reporter) return;
+  std::flush(reporter->GetOutputStream());
+  std::flush(reporter->GetErrorStream());
+}
+
+// Reports in both display and file reporters.
+void Report(BenchmarkReporter* display_reporter,
+            BenchmarkReporter* file_reporter, const RunResults& run_results) {
+  auto report_one = [](BenchmarkReporter* reporter, bool aggregates_only,
+                       const RunResults& results) {
+    assert(reporter);
+    // If there are no aggregates, do output non-aggregates.
+    aggregates_only &= !results.aggregates_only.empty();
+    if (!aggregates_only) reporter->ReportRuns(results.non_aggregates);
+    if (!results.aggregates_only.empty())
+      reporter->ReportRuns(results.aggregates_only);
+  };
+
+  report_one(display_reporter, run_results.display_report_aggregates_only,
+             run_results);
+  if (file_reporter)
+    report_one(file_reporter, run_results.file_report_aggregates_only,
+               run_results);
+
+  FlushStreams(display_reporter);
+  FlushStreams(file_reporter);
+}
+
+void RunBenchmarks(const std::vector<BenchmarkInstance>& benchmarks,
+                   BenchmarkReporter* display_reporter,
+                   BenchmarkReporter* file_reporter) {
+  // Note the file_reporter can be null.
+  BM_CHECK(display_reporter != nullptr);
+
+  // Determine the width of the name field using a minimum width of 10.
+  bool might_have_aggregates = FLAGS_benchmark_repetitions > 1;
+  size_t name_field_width = 10;
+  size_t stat_field_width = 0;
+  for (const BenchmarkInstance& benchmark : benchmarks) {
+    name_field_width =
+        std::max<size_t>(name_field_width, benchmark.name().str().size());
+    might_have_aggregates |= benchmark.repetitions() > 1;
+
+    for (const auto& Stat : benchmark.statistics())
+      stat_field_width = std::max<size_t>(stat_field_width, Stat.name_.size());
+  }
+  if (might_have_aggregates) name_field_width += 1 + stat_field_width;
+
+  // Print header here
+  BenchmarkReporter::Context context;
+  context.name_field_width = name_field_width;
+
+  // Keep track of running times of all instances of each benchmark family.
+  std::map<int /*family_index*/, BenchmarkReporter::PerFamilyRunReports>
+      per_family_reports;
+
+  if (display_reporter->ReportContext(context) &&
+      (!file_reporter || file_reporter->ReportContext(context))) {
+    FlushStreams(display_reporter);
+    FlushStreams(file_reporter);
+
+    size_t num_repetitions_total = 0;
+
+    // This perfcounters object needs to be created before the runners vector
+    // below so it outlasts their lifetime.
+    PerfCountersMeasurement perfcounters(
+        StrSplit(FLAGS_benchmark_perf_counters, ','));
+
+    // Vector of benchmarks to run
+    std::vector<internal::BenchmarkRunner> runners;
+    runners.reserve(benchmarks.size());
+
+    // Count the number of benchmarks with threads to warn the user in case
+    // performance counters are used.
+    int benchmarks_with_threads = 0;
+
+    // Loop through all benchmarks
+    for (const BenchmarkInstance& benchmark : benchmarks) {
+      BenchmarkReporter::PerFamilyRunReports* reports_for_family = nullptr;
+      if (benchmark.complexity() != oNone)
+        reports_for_family = &per_family_reports[benchmark.family_index()];
+      benchmarks_with_threads += (benchmark.threads() > 1);
+      runners.emplace_back(benchmark, &perfcounters, reports_for_family);
+      int num_repeats_of_this_instance = runners.back().GetNumRepeats();
+      num_repetitions_total +=
+          static_cast<size_t>(num_repeats_of_this_instance);
+      if (reports_for_family)
+        reports_for_family->num_runs_total += num_repeats_of_this_instance;
+    }
+    assert(runners.size() == benchmarks.size() && "Unexpected runner count.");
+
+    // The use of performance counters with threads would be unintuitive for
+    // the average user so we need to warn them about this case
+    if ((benchmarks_with_threads > 0) && (perfcounters.num_counters() > 0)) {
+      GetErrorLogInstance()
+          << "***WARNING*** There are " << benchmarks_with_threads
+          << " benchmarks with threads and " << perfcounters.num_counters()
+          << " performance counters were requested. Beware counters will "
+             "reflect the combined usage across all "
+             "threads.\n";
+    }
+
+    std::vector<size_t> repetition_indices;
+    repetition_indices.reserve(num_repetitions_total);
+    for (size_t runner_index = 0, num_runners = runners.size();
+         runner_index != num_runners; ++runner_index) {
+      const internal::BenchmarkRunner& runner = runners[runner_index];
+      std::fill_n(std::back_inserter(repetition_indices),
+                  runner.GetNumRepeats(), runner_index);
+    }
+    assert(repetition_indices.size() == num_repetitions_total &&
+           "Unexpected number of repetition indexes.");
+
+    if (FLAGS_benchmark_enable_random_interleaving) {
+      std::random_device rd;
+      std::mt19937 g(rd());
+      std::shuffle(repetition_indices.begin(), repetition_indices.end(), g);
+    }
+
+    for (size_t repetition_index : repetition_indices) {
+      internal::BenchmarkRunner& runner = runners[repetition_index];
+      runner.DoOneRepetition();
+      if (runner.HasRepeatsRemaining()) continue;
+      // FIXME: report each repetition separately, not all of them in bulk.
+
+      display_reporter->ReportRunsConfig(
+          runner.GetMinTime(), runner.HasExplicitIters(), runner.GetIters());
+      if (file_reporter)
+        file_reporter->ReportRunsConfig(
+            runner.GetMinTime(), runner.HasExplicitIters(), runner.GetIters());
+
+      RunResults run_results = runner.GetResults();
+
+      // Maybe calculate complexity report
+      if (const auto* reports_for_family = runner.GetReportsForFamily()) {
+        if (reports_for_family->num_runs_done ==
+            reports_for_family->num_runs_total) {
+          auto additional_run_stats = ComputeBigO(reports_for_family->Runs);
+          run_results.aggregates_only.insert(run_results.aggregates_only.end(),
+                                             additional_run_stats.begin(),
+                                             additional_run_stats.end());
+          per_family_reports.erase(
+              static_cast<int>(reports_for_family->Runs.front().family_index));
+        }
+      }
+
+      Report(display_reporter, file_reporter, run_results);
+    }
+  }
+  display_reporter->Finalize();
+  if (file_reporter) file_reporter->Finalize();
+  FlushStreams(display_reporter);
+  FlushStreams(file_reporter);
+}
+
+// Disable deprecated warnings temporarily because we need to reference
+// CSVReporter but don't want to trigger -Werror=-Wdeprecated-declarations
+BENCHMARK_DISABLE_DEPRECATED_WARNING
+
+std::unique_ptr<BenchmarkReporter> CreateReporter(
+    std::string const& name, ConsoleReporter::OutputOptions output_opts) {
+  typedef std::unique_ptr<BenchmarkReporter> PtrType;
+  if (name == "console") {
+    return PtrType(new ConsoleReporter(output_opts));
+  }
+  if (name == "json") {
+    return PtrType(new JSONReporter());
+  }
+  if (name == "csv") {
+    return PtrType(new CSVReporter());
+  }
+  std::cerr << "Unexpected format: '" << name << "'\n";
+  std::exit(1);
+}
+
+BENCHMARK_RESTORE_DEPRECATED_WARNING
+
+}  // end namespace
+
+bool IsZero(double n) {
+  return std::abs(n) < std::numeric_limits<double>::epsilon();
+}
+
+ConsoleReporter::OutputOptions GetOutputOptions(bool force_no_color) {
+  int output_opts = ConsoleReporter::OO_Defaults;
+  auto is_benchmark_color = [force_no_color]() -> bool {
+    if (force_no_color) {
+      return false;
+    }
+    if (FLAGS_benchmark_color == "auto") {
+      return IsColorTerminal();
+    }
+    return IsTruthyFlagValue(FLAGS_benchmark_color);
+  };
+  if (is_benchmark_color()) {
+    output_opts |= ConsoleReporter::OO_Color;
+  } else {
+    output_opts &= ~ConsoleReporter::OO_Color;
+  }
+  if (FLAGS_benchmark_counters_tabular) {
+    output_opts |= ConsoleReporter::OO_Tabular;
+  } else {
+    output_opts &= ~ConsoleReporter::OO_Tabular;
+  }
+  return static_cast<ConsoleReporter::OutputOptions>(output_opts);
+}
+
+}  // end namespace internal
+
+BenchmarkReporter* CreateDefaultDisplayReporter() {
+  static auto default_display_reporter =
+      internal::CreateReporter(FLAGS_benchmark_format,
+                               internal::GetOutputOptions())
+          .release();
+  return default_display_reporter;
+}
+
+size_t RunSpecifiedBenchmarks() {
+  return RunSpecifiedBenchmarks(nullptr, nullptr, FLAGS_benchmark_filter);
+}
+
+size_t RunSpecifiedBenchmarks(std::string spec) {
+  return RunSpecifiedBenchmarks(nullptr, nullptr, std::move(spec));
+}
+
+size_t RunSpecifiedBenchmarks(BenchmarkReporter* display_reporter) {
+  return RunSpecifiedBenchmarks(display_reporter, nullptr,
+                                FLAGS_benchmark_filter);
+}
+
+size_t RunSpecifiedBenchmarks(BenchmarkReporter* display_reporter,
+                              std::string spec) {
+  return RunSpecifiedBenchmarks(display_reporter, nullptr, std::move(spec));
+}
+
+size_t RunSpecifiedBenchmarks(BenchmarkReporter* display_reporter,
+                              BenchmarkReporter* file_reporter) {
+  return RunSpecifiedBenchmarks(display_reporter, file_reporter,
+                                FLAGS_benchmark_filter);
+}
+
+size_t RunSpecifiedBenchmarks(BenchmarkReporter* display_reporter,
+                              BenchmarkReporter* file_reporter,
+                              std::string spec) {
+  if (spec.empty() || spec == "all")
+    spec = ".";  // Regexp that matches all benchmarks
+
+  // Setup the reporters
+  std::ofstream output_file;
+  std::unique_ptr<BenchmarkReporter> default_display_reporter;
+  std::unique_ptr<BenchmarkReporter> default_file_reporter;
+  if (!display_reporter) {
+    default_display_reporter.reset(CreateDefaultDisplayReporter());
+    display_reporter = default_display_reporter.get();
+  }
+  auto& Out = display_reporter->GetOutputStream();
+  auto& Err = display_reporter->GetErrorStream();
+
+  std::string const& fname = FLAGS_benchmark_out;
+  if (fname.empty() && file_reporter) {
+    Err << "A custom file reporter was provided but "
+           "--benchmark_out=<file> was not specified."
+        << std::endl;
+    Out.flush();
+    Err.flush();
+    std::exit(1);
+  }
+  if (!fname.empty()) {
+    output_file.open(fname);
+    if (!output_file.is_open()) {
+      Err << "invalid file name: '" << fname << "'" << std::endl;
+      Out.flush();
+      Err.flush();
+      std::exit(1);
+    }
+    if (!file_reporter) {
+      default_file_reporter = internal::CreateReporter(
+          FLAGS_benchmark_out_format, FLAGS_benchmark_counters_tabular
+                                          ? ConsoleReporter::OO_Tabular
+                                          : ConsoleReporter::OO_None);
+      file_reporter = default_file_reporter.get();
+    }
+    file_reporter->SetOutputStream(&output_file);
+    file_reporter->SetErrorStream(&output_file);
+  }
+
+  std::vector<internal::BenchmarkInstance> benchmarks;
+  if (!FindBenchmarksInternal(spec, &benchmarks, &Err)) {
+    Out.flush();
+    Err.flush();
+    return 0;
+  }
+
+  if (benchmarks.empty()) {
+    Err << "Failed to match any benchmarks against regex: " << spec << "\n";
+    Out.flush();
+    Err.flush();
+    return 0;
+  }
+
+  if (FLAGS_benchmark_list_tests) {
+    for (auto const& benchmark : benchmarks)
+      Out << benchmark.name().str() << "\n";
+  } else {
+    internal::RunBenchmarks(benchmarks, display_reporter, file_reporter);
+  }
+
+  Out.flush();
+  Err.flush();
+  return benchmarks.size();
+}
+
+namespace {
+// stores the time unit benchmarks use by default
+TimeUnit default_time_unit = kNanosecond;
+}  // namespace
+
+TimeUnit GetDefaultTimeUnit() { return default_time_unit; }
+
+void SetDefaultTimeUnit(TimeUnit unit) { default_time_unit = unit; }
+
+std::string GetBenchmarkFilter() { return FLAGS_benchmark_filter; }
+
+void SetBenchmarkFilter(std::string value) {
+  FLAGS_benchmark_filter = std::move(value);
+}
+
+int32_t GetBenchmarkVerbosity() { return FLAGS_v; }
+
+void RegisterMemoryManager(MemoryManager* manager) {
+  internal::memory_manager = manager;
+}
+
+void AddCustomContext(const std::string& key, const std::string& value) {
+  if (internal::global_context == nullptr) {
+    internal::global_context = new std::map<std::string, std::string>();
+  }
+  if (!internal::global_context->emplace(key, value).second) {
+    std::cerr << "Failed to add custom context \"" << key << "\" as it already "
+              << "exists with value \"" << value << "\"\n";
+  }
+}
+
+namespace internal {
+
+void (*HelperPrintf)();
+
+void PrintUsageAndExit() {
+  HelperPrintf();
+  exit(0);
+}
+
+void SetDefaultTimeUnitFromFlag(const std::string& time_unit_flag) {
+  if (time_unit_flag == "s") {
+    return SetDefaultTimeUnit(kSecond);
+  }
+  if (time_unit_flag == "ms") {
+    return SetDefaultTimeUnit(kMillisecond);
+  }
+  if (time_unit_flag == "us") {
+    return SetDefaultTimeUnit(kMicrosecond);
+  }
+  if (time_unit_flag == "ns") {
+    return SetDefaultTimeUnit(kNanosecond);
+  }
+  if (!time_unit_flag.empty()) {
+    PrintUsageAndExit();
+  }
+}
+
+void ParseCommandLineFlags(int* argc, char** argv) {
+  using namespace benchmark;
+  BenchmarkReporter::Context::executable_name =
+      (argc && *argc > 0) ? argv[0] : "unknown";
+  for (int i = 1; argc && i < *argc; ++i) {
+    if (ParseBoolFlag(argv[i], "benchmark_list_tests",
+                      &FLAGS_benchmark_list_tests) ||
+        ParseStringFlag(argv[i], "benchmark_filter", &FLAGS_benchmark_filter) ||
+        ParseStringFlag(argv[i], "benchmark_min_time",
+                        &FLAGS_benchmark_min_time) ||
+        ParseDoubleFlag(argv[i], "benchmark_min_warmup_time",
+                        &FLAGS_benchmark_min_warmup_time) ||
+        ParseInt32Flag(argv[i], "benchmark_repetitions",
+                       &FLAGS_benchmark_repetitions) ||
+        ParseBoolFlag(argv[i], "benchmark_enable_random_interleaving",
+                      &FLAGS_benchmark_enable_random_interleaving) ||
+        ParseBoolFlag(argv[i], "benchmark_report_aggregates_only",
+                      &FLAGS_benchmark_report_aggregates_only) ||
+        ParseBoolFlag(argv[i], "benchmark_display_aggregates_only",
+                      &FLAGS_benchmark_display_aggregates_only) ||
+        ParseStringFlag(argv[i], "benchmark_format", &FLAGS_benchmark_format) ||
+        ParseStringFlag(argv[i], "benchmark_out", &FLAGS_benchmark_out) ||
+        ParseStringFlag(argv[i], "benchmark_out_format",
+                        &FLAGS_benchmark_out_format) ||
+        ParseStringFlag(argv[i], "benchmark_color", &FLAGS_benchmark_color) ||
+        ParseBoolFlag(argv[i], "benchmark_counters_tabular",
+                      &FLAGS_benchmark_counters_tabular) ||
+        ParseStringFlag(argv[i], "benchmark_perf_counters",
+                        &FLAGS_benchmark_perf_counters) ||
+        ParseKeyValueFlag(argv[i], "benchmark_context",
+                          &FLAGS_benchmark_context) ||
+        ParseStringFlag(argv[i], "benchmark_time_unit",
+                        &FLAGS_benchmark_time_unit) ||
+        ParseInt32Flag(argv[i], "v", &FLAGS_v)) {
+      for (int j = i; j != *argc - 1; ++j) argv[j] = argv[j + 1];
+
+      --(*argc);
+      --i;
+    } else if (IsFlag(argv[i], "help")) {
+      PrintUsageAndExit();
+    }
+  }
+  for (auto const* flag :
+       {&FLAGS_benchmark_format, &FLAGS_benchmark_out_format}) {
+    if (*flag != "console" && *flag != "json" && *flag != "csv") {
+      PrintUsageAndExit();
+    }
+  }
+  SetDefaultTimeUnitFromFlag(FLAGS_benchmark_time_unit);
+  if (FLAGS_benchmark_color.empty()) {
+    PrintUsageAndExit();
+  }
+  for (const auto& kv : FLAGS_benchmark_context) {
+    AddCustomContext(kv.first, kv.second);
+  }
+}
+
+int InitializeStreams() {
+  static std::ios_base::Init init;
+  return 0;
+}
+
+}  // end namespace internal
+
+std::string GetBenchmarkVersion() {
+#ifdef BENCHMARK_VERSION
+  return {BENCHMARK_VERSION};
+#else
+  return {""};
+#endif
+}
+
+void PrintDefaultHelp() {
+  fprintf(stdout,
+          "benchmark"
+          " [--benchmark_list_tests={true|false}]\n"
+          "          [--benchmark_filter=<regex>]\n"
+          "          [--benchmark_min_time=`<integer>x` OR `<float>s` ]\n"
+          "          [--benchmark_min_warmup_time=<min_warmup_time>]\n"
+          "          [--benchmark_repetitions=<num_repetitions>]\n"
+          "          [--benchmark_enable_random_interleaving={true|false}]\n"
+          "          [--benchmark_report_aggregates_only={true|false}]\n"
+          "          [--benchmark_display_aggregates_only={true|false}]\n"
+          "          [--benchmark_format=<console|json|csv>]\n"
+          "          [--benchmark_out=<filename>]\n"
+          "          [--benchmark_out_format=<json|console|csv>]\n"
+          "          [--benchmark_color={auto|true|false}]\n"
+          "          [--benchmark_counters_tabular={true|false}]\n"
+#if defined HAVE_LIBPFM
+          "          [--benchmark_perf_counters=<counter>,...]\n"
+#endif
+          "          [--benchmark_context=<key>=<value>,...]\n"
+          "          [--benchmark_time_unit={ns|us|ms|s}]\n"
+          "          [--v=<verbosity>]\n");
+}
+
+void Initialize(int* argc, char** argv, void (*HelperPrintf)()) {
+  internal::HelperPrintf = HelperPrintf;
+  internal::ParseCommandLineFlags(argc, argv);
+  internal::LogLevel() = FLAGS_v;
+}
+
+void Shutdown() { delete internal::global_context; }
+
+bool ReportUnrecognizedArguments(int argc, char** argv) {
+  for (int i = 1; i < argc; ++i) {
+    fprintf(stderr, "%s: error: unrecognized command-line flag: %s\n", argv[0],
+            argv[i]);
+  }
+  return argc > 1;
+}
+
+}  // end namespace benchmark

third_party/benchmark/src/benchmark_api_internal.cc

@@ -0,0 +1,118 @@
+#include "benchmark_api_internal.h"
+
+#include <cinttypes>
+
+#include "string_util.h"
+
+namespace benchmark {
+namespace internal {
+
+BenchmarkInstance::BenchmarkInstance(Benchmark* benchmark, int family_idx,
+                                     int per_family_instance_idx,
+                                     const std::vector<int64_t>& args,
+                                     int thread_count)
+    : benchmark_(*benchmark),
+      family_index_(family_idx),
+      per_family_instance_index_(per_family_instance_idx),
+      aggregation_report_mode_(benchmark_.aggregation_report_mode_),
+      args_(args),
+      time_unit_(benchmark_.GetTimeUnit()),
+      measure_process_cpu_time_(benchmark_.measure_process_cpu_time_),
+      use_real_time_(benchmark_.use_real_time_),
+      use_manual_time_(benchmark_.use_manual_time_),
+      complexity_(benchmark_.complexity_),
+      complexity_lambda_(benchmark_.complexity_lambda_),
+      statistics_(benchmark_.statistics_),
+      repetitions_(benchmark_.repetitions_),
+      min_time_(benchmark_.min_time_),
+      min_warmup_time_(benchmark_.min_warmup_time_),
+      iterations_(benchmark_.iterations_),
+      threads_(thread_count) {
+  name_.function_name = benchmark_.name_;
+
+  size_t arg_i = 0;
+  for (const auto& arg : args) {
+    if (!name_.args.empty()) {
+      name_.args += '/';
+    }
+
+    if (arg_i < benchmark->arg_names_.size()) {
+      const auto& arg_name = benchmark_.arg_names_[arg_i];
+      if (!arg_name.empty()) {
+        name_.args += StrFormat("%s:", arg_name.c_str());
+      }
+    }
+
+    name_.args += StrFormat("%" PRId64, arg);
+    ++arg_i;
+  }
+
+  if (!IsZero(benchmark->min_time_)) {
+    name_.min_time = StrFormat("min_time:%0.3f", benchmark_.min_time_);
+  }
+
+  if (!IsZero(benchmark->min_warmup_time_)) {
+    name_.min_warmup_time =
+        StrFormat("min_warmup_time:%0.3f", benchmark_.min_warmup_time_);
+  }
+
+  if (benchmark_.iterations_ != 0) {
+    name_.iterations = StrFormat(
+        "iterations:%lu", static_cast<unsigned long>(benchmark_.iterations_));
+  }
+
+  if (benchmark_.repetitions_ != 0) {
+    name_.repetitions = StrFormat("repeats:%d", benchmark_.repetitions_);
+  }
+
+  if (benchmark_.measure_process_cpu_time_) {
+    name_.time_type = "process_time";
+  }
+
+  if (benchmark_.use_manual_time_) {
+    if (!name_.time_type.empty()) {
+      name_.time_type += '/';
+    }
+    name_.time_type += "manual_time";
+  } else if (benchmark_.use_real_time_) {
+    if (!name_.time_type.empty()) {
+      name_.time_type += '/';
+    }
+    name_.time_type += "real_time";
+  }
+
+  if (!benchmark_.thread_counts_.empty()) {
+    name_.threads = StrFormat("threads:%d", threads_);
+  }
+
+  setup_ = benchmark_.setup_;
+  teardown_ = benchmark_.teardown_;
+}
+
+State BenchmarkInstance::Run(
+    IterationCount iters, int thread_id, internal::ThreadTimer* timer,
+    internal::ThreadManager* manager,
+    internal::PerfCountersMeasurement* perf_counters_measurement) const {
+  State st(name_.function_name, iters, args_, thread_id, threads_, timer,
+           manager, perf_counters_measurement);
+  benchmark_.Run(st);
+  return st;
+}
+
+void BenchmarkInstance::Setup() const {
+  if (setup_) {
+    State st(name_.function_name, /*iters*/ 1, args_, /*thread_id*/ 0, threads_,
+             nullptr, nullptr, nullptr);
+    setup_(st);
+  }
+}
+
+void BenchmarkInstance::Teardown() const {
+  if (teardown_) {
+    State st(name_.function_name, /*iters*/ 1, args_, /*thread_id*/ 0, threads_,
+             nullptr, nullptr, nullptr);
+    teardown_(st);
+  }
+}
+}  // namespace internal
+}  // namespace benchmark

third_party/benchmark/src/benchmark_api_internal.h

@@ -0,0 +1,87 @@
+#ifndef BENCHMARK_API_INTERNAL_H
+#define BENCHMARK_API_INTERNAL_H
+
+#include <cmath>
+#include <iosfwd>
+#include <limits>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "benchmark/benchmark.h"
+#include "commandlineflags.h"
+
+namespace benchmark {
+namespace internal {
+
+// Information kept per benchmark we may want to run
+class BenchmarkInstance {
+ public:
+  BenchmarkInstance(Benchmark* benchmark, int family_index,
+                    int per_family_instance_index,
+                    const std::vector<int64_t>& args, int threads);
+
+  const BenchmarkName& name() const { return name_; }
+  int family_index() const { return family_index_; }
+  int per_family_instance_index() const { return per_family_instance_index_; }
+  AggregationReportMode aggregation_report_mode() const {
+    return aggregation_report_mode_;
+  }
+  TimeUnit time_unit() const { return time_unit_; }
+  bool measure_process_cpu_time() const { return measure_process_cpu_time_; }
+  bool use_real_time() const { return use_real_time_; }
+  bool use_manual_time() const { return use_manual_time_; }
+  BigO complexity() const { return complexity_; }
+  BigOFunc* complexity_lambda() const { return complexity_lambda_; }
+  const std::vector<Statistics>& statistics() const { return statistics_; }
+  int repetitions() const { return repetitions_; }
+  double min_time() const { return min_time_; }
+  double min_warmup_time() const { return min_warmup_time_; }
+  IterationCount iterations() const { return iterations_; }
+  int threads() const { return threads_; }
+  void Setup() const;
+  void Teardown() const;
+
+  State Run(IterationCount iters, int thread_id, internal::ThreadTimer* timer,
+            internal::ThreadManager* manager,
+            internal::PerfCountersMeasurement* perf_counters_measurement) const;
+
+ private:
+  BenchmarkName name_;
+  Benchmark& benchmark_;
+  const int family_index_;
+  const int per_family_instance_index_;
+  AggregationReportMode aggregation_report_mode_;
+  const std::vector<int64_t>& args_;
+  TimeUnit time_unit_;
+  bool measure_process_cpu_time_;
+  bool use_real_time_;
+  bool use_manual_time_;
+  BigO complexity_;
+  BigOFunc* complexity_lambda_;
+  UserCounters counters_;
+  const std::vector<Statistics>& statistics_;
+  int repetitions_;
+  double min_time_;
+  double min_warmup_time_;
+  IterationCount iterations_;
+  int threads_;  // Number of concurrent threads to us
+
+  typedef void (*callback_function)(const benchmark::State&);
+  callback_function setup_ = nullptr;
+  callback_function teardown_ = nullptr;
+};
+
+bool FindBenchmarksInternal(const std::string& re,
+                            std::vector<BenchmarkInstance>* benchmarks,
+                            std::ostream* Err);
+
+bool IsZero(double n);
+
+BENCHMARK_EXPORT
+ConsoleReporter::OutputOptions GetOutputOptions(bool force_no_color = false);
+
+}  // end namespace internal
+}  // end namespace benchmark
+
+#endif  // BENCHMARK_API_INTERNAL_H

third_party/benchmark/src/benchmark_main.cc

@@ -0,0 +1,18 @@
+// Copyright 2018 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "benchmark/benchmark.h"
+
+BENCHMARK_EXPORT int main(int, char**);
+BENCHMARK_MAIN();

third_party/benchmark/src/benchmark_name.cc

@@ -0,0 +1,59 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <benchmark/benchmark.h>
+
+namespace benchmark {
+
+namespace {
+
+// Compute the total size of a pack of std::strings
+size_t size_impl() { return 0; }
+
+template <typename Head, typename... Tail>
+size_t size_impl(const Head& head, const Tail&... tail) {
+  return head.size() + size_impl(tail...);
+}
+
+// Join a pack of std::strings using a delimiter
+// TODO: use absl::StrJoin
+void join_impl(std::string&, char) {}
+
+template <typename Head, typename... Tail>
+void join_impl(std::string& s, const char delimiter, const Head& head,
+               const Tail&... tail) {
+  if (!s.empty() && !head.empty()) {
+    s += delimiter;
+  }
+
+  s += head;
+
+  join_impl(s, delimiter, tail...);
+}
+
+template <typename... Ts>
+std::string join(char delimiter, const Ts&... ts) {
+  std::string s;
+  s.reserve(sizeof...(Ts) + size_impl(ts...));
+  join_impl(s, delimiter, ts...);
+  return s;
+}
+}  // namespace
+
+BENCHMARK_EXPORT
+std::string BenchmarkName::str() const {
+  return join('/', function_name, args, min_time, min_warmup_time, iterations,
+              repetitions, time_type, threads);
+}
+}  // namespace benchmark

third_party/benchmark/src/benchmark_register.cc

@@ -0,0 +1,521 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "benchmark_register.h"
+
+#ifndef BENCHMARK_OS_WINDOWS
+#if !defined(BENCHMARK_OS_FUCHSIA) && !defined(BENCHMARK_OS_QURT)
+#include <sys/resource.h>
+#endif
+#include <sys/time.h>
+#include <unistd.h>
+#endif
+
+#include <algorithm>
+#include <atomic>
+#include <cinttypes>
+#include <condition_variable>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <iostream>
+#include <memory>
+#include <numeric>
+#include <sstream>
+#include <thread>
+
+#include "benchmark/benchmark.h"
+#include "benchmark_api_internal.h"
+#include "check.h"
+#include "commandlineflags.h"
+#include "complexity.h"
+#include "internal_macros.h"
+#include "log.h"
+#include "mutex.h"
+#include "re.h"
+#include "statistics.h"
+#include "string_util.h"
+#include "timers.h"
+
+namespace benchmark {
+
+namespace {
+// For non-dense Range, intermediate values are powers of kRangeMultiplier.
+static constexpr int kRangeMultiplier = 8;
+
+// The size of a benchmark family determines is the number of inputs to repeat
+// the benchmark on. If this is "large" then warn the user during configuration.
+static constexpr size_t kMaxFamilySize = 100;
+
+static constexpr char kDisabledPrefix[] = "DISABLED_";
+}  // end namespace
+
+namespace internal {
+
+//=============================================================================//
+//                         BenchmarkFamilies
+//=============================================================================//
+
+// Class for managing registered benchmarks.  Note that each registered
+// benchmark identifies a family of related benchmarks to run.
+class BenchmarkFamilies {
+ public:
+  static BenchmarkFamilies* GetInstance();
+
+  // Registers a benchmark family and returns the index assigned to it.
+  size_t AddBenchmark(std::unique_ptr<Benchmark> family);
+
+  // Clear all registered benchmark families.
+  void ClearBenchmarks();
+
+  // Extract the list of benchmark instances that match the specified
+  // regular expression.
+  bool FindBenchmarks(std::string re,
+                      std::vector<BenchmarkInstance>* benchmarks,
+                      std::ostream* Err);
+
+ private:
+  BenchmarkFamilies() {}
+
+  std::vector<std::unique_ptr<Benchmark>> families_;
+  Mutex mutex_;
+};
+
+BenchmarkFamilies* BenchmarkFamilies::GetInstance() {
+  static BenchmarkFamilies instance;
+  return &instance;
+}
+
+size_t BenchmarkFamilies::AddBenchmark(std::unique_ptr<Benchmark> family) {
+  MutexLock l(mutex_);
+  size_t index = families_.size();
+  families_.push_back(std::move(family));
+  return index;
+}
+
+void BenchmarkFamilies::ClearBenchmarks() {
+  MutexLock l(mutex_);
+  families_.clear();
+  families_.shrink_to_fit();
+}
+
+bool BenchmarkFamilies::FindBenchmarks(
+    std::string spec, std::vector<BenchmarkInstance>* benchmarks,
+    std::ostream* ErrStream) {
+  BM_CHECK(ErrStream);
+  auto& Err = *ErrStream;
+  // Make regular expression out of command-line flag
+  std::string error_msg;
+  Regex re;
+  bool is_negative_filter = false;
+  if (spec[0] == '-') {
+    spec.replace(0, 1, "");
+    is_negative_filter = true;
+  }
+  if (!re.Init(spec, &error_msg)) {
+    Err << "Could not compile benchmark re: " << error_msg << std::endl;
+    return false;
+  }
+
+  // Special list of thread counts to use when none are specified
+  const std::vector<int> one_thread = {1};
+
+  int next_family_index = 0;
+
+  MutexLock l(mutex_);
+  for (std::unique_ptr<Benchmark>& family : families_) {
+    int family_index = next_family_index;
+    int per_family_instance_index = 0;
+
+    // Family was deleted or benchmark doesn't match
+    if (!family) continue;
+
+    if (family->ArgsCnt() == -1) {
+      family->Args({});
+    }
+    const std::vector<int>* thread_counts =
+        (family->thread_counts_.empty()
+             ? &one_thread
+             : &static_cast<const std::vector<int>&>(family->thread_counts_));
+    const size_t family_size = family->args_.size() * thread_counts->size();
+    // The benchmark will be run at least 'family_size' different inputs.
+    // If 'family_size' is very large warn the user.
+    if (family_size > kMaxFamilySize) {
+      Err << "The number of inputs is very large. " << family->name_
+          << " will be repeated at least " << family_size << " times.\n";
+    }
+    // reserve in the special case the regex ".", since we know the final
+    // family size.  this doesn't take into account any disabled benchmarks
+    // so worst case we reserve more than we need.
+    if (spec == ".") benchmarks->reserve(benchmarks->size() + family_size);
+
+    for (auto const& args : family->args_) {
+      for (int num_threads : *thread_counts) {
+        BenchmarkInstance instance(family.get(), family_index,
+                                   per_family_instance_index, args,
+                                   num_threads);
+
+        const auto full_name = instance.name().str();
+        if (full_name.rfind(kDisabledPrefix, 0) != 0 &&
+            ((re.Match(full_name) && !is_negative_filter) ||
+             (!re.Match(full_name) && is_negative_filter))) {
+          benchmarks->push_back(std::move(instance));
+
+          ++per_family_instance_index;
+
+          // Only bump the next family index once we've estabilished that
+          // at least one instance of this family will be run.
+          if (next_family_index == family_index) ++next_family_index;
+        }
+      }
+    }
+  }
+  return true;
+}
+
+Benchmark* RegisterBenchmarkInternal(Benchmark* bench) {
+  std::unique_ptr<Benchmark> bench_ptr(bench);
+  BenchmarkFamilies* families = BenchmarkFamilies::GetInstance();
+  families->AddBenchmark(std::move(bench_ptr));
+  return bench;
+}
+
+// FIXME: This function is a hack so that benchmark.cc can access
+// `BenchmarkFamilies`
+bool FindBenchmarksInternal(const std::string& re,
+                            std::vector<BenchmarkInstance>* benchmarks,
+                            std::ostream* Err) {
+  return BenchmarkFamilies::GetInstance()->FindBenchmarks(re, benchmarks, Err);
+}
+
+//=============================================================================//
+//                               Benchmark
+//=============================================================================//
+
+Benchmark::Benchmark(const std::string& name)
+    : name_(name),
+      aggregation_report_mode_(ARM_Unspecified),
+      time_unit_(GetDefaultTimeUnit()),
+      use_default_time_unit_(true),
+      range_multiplier_(kRangeMultiplier),
+      min_time_(0),
+      min_warmup_time_(0),
+      iterations_(0),
+      repetitions_(0),
+      measure_process_cpu_time_(false),
+      use_real_time_(false),
+      use_manual_time_(false),
+      complexity_(oNone),
+      complexity_lambda_(nullptr),
+      setup_(nullptr),
+      teardown_(nullptr) {
+  ComputeStatistics("mean", StatisticsMean);
+  ComputeStatistics("median", StatisticsMedian);
+  ComputeStatistics("stddev", StatisticsStdDev);
+  ComputeStatistics("cv", StatisticsCV, kPercentage);
+}
+
+Benchmark::~Benchmark() {}
+
+Benchmark* Benchmark::Name(const std::string& name) {
+  SetName(name);
+  return this;
+}
+
+Benchmark* Benchmark::Arg(int64_t x) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == 1);
+  args_.push_back({x});
+  return this;
+}
+
+Benchmark* Benchmark::Unit(TimeUnit unit) {
+  time_unit_ = unit;
+  use_default_time_unit_ = false;
+  return this;
+}
+
+Benchmark* Benchmark::Range(int64_t start, int64_t limit) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == 1);
+  std::vector<int64_t> arglist;
+  AddRange(&arglist, start, limit, range_multiplier_);
+
+  for (int64_t i : arglist) {
+    args_.push_back({i});
+  }
+  return this;
+}
+
+Benchmark* Benchmark::Ranges(
+    const std::vector<std::pair<int64_t, int64_t>>& ranges) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == static_cast<int>(ranges.size()));
+  std::vector<std::vector<int64_t>> arglists(ranges.size());
+  for (std::size_t i = 0; i < ranges.size(); i++) {
+    AddRange(&arglists[i], ranges[i].first, ranges[i].second,
+             range_multiplier_);
+  }
+
+  ArgsProduct(arglists);
+
+  return this;
+}
+
+Benchmark* Benchmark::ArgsProduct(
+    const std::vector<std::vector<int64_t>>& arglists) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == static_cast<int>(arglists.size()));
+
+  std::vector<std::size_t> indices(arglists.size());
+  const std::size_t total = std::accumulate(
+      std::begin(arglists), std::end(arglists), std::size_t{1},
+      [](const std::size_t res, const std::vector<int64_t>& arglist) {
+        return res * arglist.size();
+      });
+  std::vector<int64_t> args;
+  args.reserve(arglists.size());
+  for (std::size_t i = 0; i < total; i++) {
+    for (std::size_t arg = 0; arg < arglists.size(); arg++) {
+      args.push_back(arglists[arg][indices[arg]]);
+    }
+    args_.push_back(args);
+    args.clear();
+
+    std::size_t arg = 0;
+    do {
+      indices[arg] = (indices[arg] + 1) % arglists[arg].size();
+    } while (indices[arg++] == 0 && arg < arglists.size());
+  }
+
+  return this;
+}
+
+Benchmark* Benchmark::ArgName(const std::string& name) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == 1);
+  arg_names_ = {name};
+  return this;
+}
+
+Benchmark* Benchmark::ArgNames(const std::vector<std::string>& names) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == static_cast<int>(names.size()));
+  arg_names_ = names;
+  return this;
+}
+
+Benchmark* Benchmark::DenseRange(int64_t start, int64_t limit, int step) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == 1);
+  BM_CHECK_LE(start, limit);
+  for (int64_t arg = start; arg <= limit; arg += step) {
+    args_.push_back({arg});
+  }
+  return this;
+}
+
+Benchmark* Benchmark::Args(const std::vector<int64_t>& args) {
+  BM_CHECK(ArgsCnt() == -1 || ArgsCnt() == static_cast<int>(args.size()));
+  args_.push_back(args);
+  return this;
+}
+
+Benchmark* Benchmark::Apply(void (*custom_arguments)(Benchmark* benchmark)) {
+  custom_arguments(this);
+  return this;
+}
+
+Benchmark* Benchmark::Setup(void (*setup)(const benchmark::State&)) {
+  BM_CHECK(setup != nullptr);
+  setup_ = setup;
+  return this;
+}
+
+Benchmark* Benchmark::Teardown(void (*teardown)(const benchmark::State&)) {
+  BM_CHECK(teardown != nullptr);
+  teardown_ = teardown;
+  return this;
+}
+
+Benchmark* Benchmark::RangeMultiplier(int multiplier) {
+  BM_CHECK(multiplier > 1);
+  range_multiplier_ = multiplier;
+  return this;
+}
+
+Benchmark* Benchmark::MinTime(double t) {
+  BM_CHECK(t > 0.0);
+  BM_CHECK(iterations_ == 0);
+  min_time_ = t;
+  return this;
+}
+
+Benchmark* Benchmark::MinWarmUpTime(double t) {
+  BM_CHECK(t >= 0.0);
+  BM_CHECK(iterations_ == 0);
+  min_warmup_time_ = t;
+  return this;
+}
+
+Benchmark* Benchmark::Iterations(IterationCount n) {
+  BM_CHECK(n > 0);
+  BM_CHECK(IsZero(min_time_));
+  BM_CHECK(IsZero(min_warmup_time_));
+  iterations_ = n;
+  return this;
+}
+
+Benchmark* Benchmark::Repetitions(int n) {
+  BM_CHECK(n > 0);
+  repetitions_ = n;
+  return this;
+}
+
+Benchmark* Benchmark::ReportAggregatesOnly(bool value) {
+  aggregation_report_mode_ = value ? ARM_ReportAggregatesOnly : ARM_Default;
+  return this;
+}
+
+Benchmark* Benchmark::DisplayAggregatesOnly(bool value) {
+  // If we were called, the report mode is no longer 'unspecified', in any case.
+  aggregation_report_mode_ = static_cast<AggregationReportMode>(
+      aggregation_report_mode_ | ARM_Default);
+
+  if (value) {
+    aggregation_report_mode_ = static_cast<AggregationReportMode>(
+        aggregation_report_mode_ | ARM_DisplayReportAggregatesOnly);
+  } else {
+    aggregation_report_mode_ = static_cast<AggregationReportMode>(
+        aggregation_report_mode_ & ~ARM_DisplayReportAggregatesOnly);
+  }
+
+  return this;
+}
+
+Benchmark* Benchmark::MeasureProcessCPUTime() {
+  // Can be used together with UseRealTime() / UseManualTime().
+  measure_process_cpu_time_ = true;
+  return this;
+}
+
+Benchmark* Benchmark::UseRealTime() {
+  BM_CHECK(!use_manual_time_)
+      << "Cannot set UseRealTime and UseManualTime simultaneously.";
+  use_real_time_ = true;
+  return this;
+}
+
+Benchmark* Benchmark::UseManualTime() {
+  BM_CHECK(!use_real_time_)
+      << "Cannot set UseRealTime and UseManualTime simultaneously.";
+  use_manual_time_ = true;
+  return this;
+}
+
+Benchmark* Benchmark::Complexity(BigO complexity) {
+  complexity_ = complexity;
+  return this;
+}
+
+Benchmark* Benchmark::Complexity(BigOFunc* complexity) {
+  complexity_lambda_ = complexity;
+  complexity_ = oLambda;
+  return this;
+}
+
+Benchmark* Benchmark::ComputeStatistics(const std::string& name,
+                                        StatisticsFunc* statistics,
+                                        StatisticUnit unit) {
+  statistics_.emplace_back(name, statistics, unit);
+  return this;
+}
+
+Benchmark* Benchmark::Threads(int t) {
+  BM_CHECK_GT(t, 0);
+  thread_counts_.push_back(t);
+  return this;
+}
+
+Benchmark* Benchmark::ThreadRange(int min_threads, int max_threads) {
+  BM_CHECK_GT(min_threads, 0);
+  BM_CHECK_GE(max_threads, min_threads);
+
+  AddRange(&thread_counts_, min_threads, max_threads, 2);
+  return this;
+}
+
+Benchmark* Benchmark::DenseThreadRange(int min_threads, int max_threads,
+                                       int stride) {
+  BM_CHECK_GT(min_threads, 0);
+  BM_CHECK_GE(max_threads, min_threads);
+  BM_CHECK_GE(stride, 1);
+
+  for (auto i = min_threads; i < max_threads; i += stride) {
+    thread_counts_.push_back(i);
+  }
+  thread_counts_.push_back(max_threads);
+  return this;
+}
+
+Benchmark* Benchmark::ThreadPerCpu() {
+  thread_counts_.push_back(CPUInfo::Get().num_cpus);
+  return this;
+}
+
+void Benchmark::SetName(const std::string& name) { name_ = name; }
+
+const char* Benchmark::GetName() const { return name_.c_str(); }
+
+int Benchmark::ArgsCnt() const {
+  if (args_.empty()) {
+    if (arg_names_.empty()) return -1;
+    return static_cast<int>(arg_names_.size());
+  }
+  return static_cast<int>(args_.front().size());
+}
+
+const char* Benchmark::GetArgName(int arg) const {
+  BM_CHECK_GE(arg, 0);
+  size_t uarg = static_cast<size_t>(arg);
+  BM_CHECK_LT(uarg, arg_names_.size());
+  return arg_names_[uarg].c_str();
+}
+
+TimeUnit Benchmark::GetTimeUnit() const {
+  return use_default_time_unit_ ? GetDefaultTimeUnit() : time_unit_;
+}
+
+//=============================================================================//
+//                            FunctionBenchmark
+//=============================================================================//
+
+void FunctionBenchmark::Run(State& st) { func_(st); }
+
+}  // end namespace internal
+
+void ClearRegisteredBenchmarks() {
+  internal::BenchmarkFamilies::GetInstance()->ClearBenchmarks();
+}
+
+std::vector<int64_t> CreateRange(int64_t lo, int64_t hi, int multi) {
+  std::vector<int64_t> args;
+  internal::AddRange(&args, lo, hi, multi);
+  return args;
+}
+
+std::vector<int64_t> CreateDenseRange(int64_t start, int64_t limit, int step) {
+  BM_CHECK_LE(start, limit);
+  std::vector<int64_t> args;
+  for (int64_t arg = start; arg <= limit; arg += step) {
+    args.push_back(arg);
+  }
+  return args;
+}
+
+}  // end namespace benchmark

third_party/benchmark/src/benchmark_register.h

@@ -0,0 +1,109 @@
+#ifndef BENCHMARK_REGISTER_H
+#define BENCHMARK_REGISTER_H
+
+#include <algorithm>
+#include <limits>
+#include <vector>
+
+#include "check.h"
+
+namespace benchmark {
+namespace internal {
+
+// Append the powers of 'mult' in the closed interval [lo, hi].
+// Returns iterator to the start of the inserted range.
+template <typename T>
+typename std::vector<T>::iterator AddPowers(std::vector<T>* dst, T lo, T hi,
+                                            int mult) {
+  BM_CHECK_GE(lo, 0);
+  BM_CHECK_GE(hi, lo);
+  BM_CHECK_GE(mult, 2);
+
+  const size_t start_offset = dst->size();
+
+  static const T kmax = std::numeric_limits<T>::max();
+
+  // Space out the values in multiples of "mult"
+  for (T i = static_cast<T>(1); i <= hi; i = static_cast<T>(i * mult)) {
+    if (i >= lo) {
+      dst->push_back(i);
+    }
+    // Break the loop here since multiplying by
+    // 'mult' would move outside of the range of T
+    if (i > kmax / mult) break;
+  }
+
+  return dst->begin() + static_cast<int>(start_offset);
+}
+
+template <typename T>
+void AddNegatedPowers(std::vector<T>* dst, T lo, T hi, int mult) {
+  // We negate lo and hi so we require that they cannot be equal to 'min'.
+  BM_CHECK_GT(lo, std::numeric_limits<T>::min());
+  BM_CHECK_GT(hi, std::numeric_limits<T>::min());
+  BM_CHECK_GE(hi, lo);
+  BM_CHECK_LE(hi, 0);
+
+  // Add positive powers, then negate and reverse.
+  // Casts necessary since small integers get promoted
+  // to 'int' when negating.
+  const auto lo_complement = static_cast<T>(-lo);
+  const auto hi_complement = static_cast<T>(-hi);
+
+  const auto it = AddPowers(dst, hi_complement, lo_complement, mult);
+
+  std::for_each(it, dst->end(), [](T& t) { t = static_cast<T>(t * -1); });
+  std::reverse(it, dst->end());
+}
+
+template <typename T>
+void AddRange(std::vector<T>* dst, T lo, T hi, int mult) {
+  static_assert(std::is_integral<T>::value && std::is_signed<T>::value,
+                "Args type must be a signed integer");
+
+  BM_CHECK_GE(hi, lo);
+  BM_CHECK_GE(mult, 2);
+
+  // Add "lo"
+  dst->push_back(lo);
+
+  // Handle lo == hi as a special case, so we then know
+  // lo < hi and so it is safe to add 1 to lo and subtract 1
+  // from hi without falling outside of the range of T.
+  if (lo == hi) return;
+
+  // Ensure that lo_inner <= hi_inner below.
+  if (lo + 1 == hi) {
+    dst->push_back(hi);
+    return;
+  }
+
+  // Add all powers of 'mult' in the range [lo+1, hi-1] (inclusive).
+  const auto lo_inner = static_cast<T>(lo + 1);
+  const auto hi_inner = static_cast<T>(hi - 1);
+
+  // Insert negative values
+  if (lo_inner < 0) {
+    AddNegatedPowers(dst, lo_inner, std::min(hi_inner, T{-1}), mult);
+  }
+
+  // Treat 0 as a special case (see discussion on #762).
+  if (lo < 0 && hi >= 0) {
+    dst->push_back(0);
+  }
+
+  // Insert positive values
+  if (hi_inner > 0) {
+    AddPowers(dst, std::max(lo_inner, T{1}), hi_inner, mult);
+  }
+
+  // Add "hi" (if different from last value).
+  if (hi != dst->back()) {
+    dst->push_back(hi);
+  }
+}
+
+}  // namespace internal
+}  // namespace benchmark
+
+#endif  // BENCHMARK_REGISTER_H

third_party/benchmark/src/benchmark_runner.cc

@@ -0,0 +1,498 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "benchmark_runner.h"
+
+#include "benchmark/benchmark.h"
+#include "benchmark_api_internal.h"
+#include "internal_macros.h"
+
+#ifndef BENCHMARK_OS_WINDOWS
+#if !defined(BENCHMARK_OS_FUCHSIA) && !defined(BENCHMARK_OS_QURT)
+#include <sys/resource.h>
+#endif
+#include <sys/time.h>
+#include <unistd.h>
+#endif
+
+#include <algorithm>
+#include <atomic>
+#include <climits>
+#include <cmath>
+#include <condition_variable>
+#include <cstdio>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <limits>
+#include <memory>
+#include <string>
+#include <thread>
+#include <utility>
+
+#include "check.h"
+#include "colorprint.h"
+#include "commandlineflags.h"
+#include "complexity.h"
+#include "counter.h"
+#include "internal_macros.h"
+#include "log.h"
+#include "mutex.h"
+#include "perf_counters.h"
+#include "re.h"
+#include "statistics.h"
+#include "string_util.h"
+#include "thread_manager.h"
+#include "thread_timer.h"
+
+namespace benchmark {
+
+namespace internal {
+
+MemoryManager* memory_manager = nullptr;
+
+namespace {
+
+static constexpr IterationCount kMaxIterations = 1000000000000;
+const double kDefaultMinTime =
+    std::strtod(::benchmark::kDefaultMinTimeStr, /*p_end*/ nullptr);
+
+BenchmarkReporter::Run CreateRunReport(
+    const benchmark::internal::BenchmarkInstance& b,
+    const internal::ThreadManager::Result& results,
+    IterationCount memory_iterations,
+    const MemoryManager::Result* memory_result, double seconds,
+    int64_t repetition_index, int64_t repeats) {
+  // Create report about this benchmark run.
+  BenchmarkReporter::Run report;
+
+  report.run_name = b.name();
+  report.family_index = b.family_index();
+  report.per_family_instance_index = b.per_family_instance_index();
+  report.skipped = results.skipped_;
+  report.skip_message = results.skip_message_;
+  report.report_label = results.report_label_;
+  // This is the total iterations across all threads.
+  report.iterations = results.iterations;
+  report.time_unit = b.time_unit();
+  report.threads = b.threads();
+  report.repetition_index = repetition_index;
+  report.repetitions = repeats;
+
+  if (!report.skipped) {
+    if (b.use_manual_time()) {
+      report.real_accumulated_time = results.manual_time_used;
+    } else {
+      report.real_accumulated_time = results.real_time_used;
+    }
+    report.use_real_time_for_initial_big_o = b.use_manual_time();
+    report.cpu_accumulated_time = results.cpu_time_used;
+    report.complexity_n = results.complexity_n;
+    report.complexity = b.complexity();
+    report.complexity_lambda = b.complexity_lambda();
+    report.statistics = &b.statistics();
+    report.counters = results.counters;
+
+    if (memory_iterations > 0) {
+      assert(memory_result != nullptr);
+      report.memory_result = memory_result;
+      report.allocs_per_iter =
+          memory_iterations ? static_cast<double>(memory_result->num_allocs) /
+                                  static_cast<double>(memory_iterations)
+                            : 0;
+    }
+
+    internal::Finish(&report.counters, results.iterations, seconds,
+                     b.threads());
+  }
+  return report;
+}
+
+// Execute one thread of benchmark b for the specified number of iterations.
+// Adds the stats collected for the thread into manager->results.
+void RunInThread(const BenchmarkInstance* b, IterationCount iters,
+                 int thread_id, ThreadManager* manager,
+                 PerfCountersMeasurement* perf_counters_measurement) {
+  internal::ThreadTimer timer(
+      b->measure_process_cpu_time()
+          ? internal::ThreadTimer::CreateProcessCpuTime()
+          : internal::ThreadTimer::Create());
+
+  State st =
+      b->Run(iters, thread_id, &timer, manager, perf_counters_measurement);
+  BM_CHECK(st.skipped() || st.iterations() >= st.max_iterations)
+      << "Benchmark returned before State::KeepRunning() returned false!";
+  {
+    MutexLock l(manager->GetBenchmarkMutex());
+    internal::ThreadManager::Result& results = manager->results;
+    results.iterations += st.iterations();
+    results.cpu_time_used += timer.cpu_time_used();
+    results.real_time_used += timer.real_time_used();
+    results.manual_time_used += timer.manual_time_used();
+    results.complexity_n += st.complexity_length_n();
+    internal::Increment(&results.counters, st.counters);
+  }
+  manager->NotifyThreadComplete();
+}
+
+double ComputeMinTime(const benchmark::internal::BenchmarkInstance& b,
+                      const BenchTimeType& iters_or_time) {
+  if (!IsZero(b.min_time())) return b.min_time();
+  // If the flag was used to specify number of iters, then return the default
+  // min_time.
+  if (iters_or_time.tag == BenchTimeType::ITERS) return kDefaultMinTime;
+
+  return iters_or_time.time;
+}
+
+IterationCount ComputeIters(const benchmark::internal::BenchmarkInstance& b,
+                            const BenchTimeType& iters_or_time) {
+  if (b.iterations() != 0) return b.iterations();
+
+  // We've already concluded that this flag is currently used to pass
+  // iters but do a check here again anyway.
+  BM_CHECK(iters_or_time.tag == BenchTimeType::ITERS);
+  return iters_or_time.iters;
+}
+
+}  // end namespace
+
+BenchTimeType ParseBenchMinTime(const std::string& value) {
+  BenchTimeType ret;
+
+  if (value.empty()) {
+    ret.tag = BenchTimeType::TIME;
+    ret.time = 0.0;
+    return ret;
+  }
+
+  if (value.back() == 'x') {
+    char* p_end;
+    // Reset errno before it's changed by strtol.
+    errno = 0;
+    IterationCount num_iters = std::strtol(value.c_str(), &p_end, 10);
+
+    // After a valid parse, p_end should have been set to
+    // point to the 'x' suffix.
+    BM_CHECK(errno == 0 && p_end != nullptr && *p_end == 'x')
+        << "Malformed iters value passed to --benchmark_min_time: `" << value
+        << "`. Expected --benchmark_min_time=<integer>x.";
+
+    ret.tag = BenchTimeType::ITERS;
+    ret.iters = num_iters;
+    return ret;
+  }
+
+  bool has_suffix = value.back() == 's';
+  if (!has_suffix) {
+    BM_VLOG(0) << "Value passed to --benchmark_min_time should have a suffix. "
+                  "Eg., `30s` for 30-seconds.";
+  }
+
+  char* p_end;
+  // Reset errno before it's changed by strtod.
+  errno = 0;
+  double min_time = std::strtod(value.c_str(), &p_end);
+
+  // After a successful parse, p_end should point to the suffix 's',
+  // or the end of the string if the suffix was omitted.
+  BM_CHECK(errno == 0 && p_end != nullptr &&
+           ((has_suffix && *p_end == 's') || *p_end == '\0'))
+      << "Malformed seconds value passed to --benchmark_min_time: `" << value
+      << "`. Expected --benchmark_min_time=<float>x.";
+
+  ret.tag = BenchTimeType::TIME;
+  ret.time = min_time;
+
+  return ret;
+}
+
+BenchmarkRunner::BenchmarkRunner(
+    const benchmark::internal::BenchmarkInstance& b_,
+    PerfCountersMeasurement* pcm_,
+    BenchmarkReporter::PerFamilyRunReports* reports_for_family_)
+    : b(b_),
+      reports_for_family(reports_for_family_),
+      parsed_benchtime_flag(ParseBenchMinTime(FLAGS_benchmark_min_time)),
+      min_time(ComputeMinTime(b_, parsed_benchtime_flag)),
+      min_warmup_time((!IsZero(b.min_time()) && b.min_warmup_time() > 0.0)
+                          ? b.min_warmup_time()
+                          : FLAGS_benchmark_min_warmup_time),
+      warmup_done(!(min_warmup_time > 0.0)),
+      repeats(b.repetitions() != 0 ? b.repetitions()
+                                   : FLAGS_benchmark_repetitions),
+      has_explicit_iteration_count(b.iterations() != 0 ||
+                                   parsed_benchtime_flag.tag ==
+                                       BenchTimeType::ITERS),
+      pool(static_cast<size_t>(b.threads() - 1)),
+      iters(has_explicit_iteration_count
+                ? ComputeIters(b_, parsed_benchtime_flag)
+                : 1),
+      perf_counters_measurement_ptr(pcm_) {
+  run_results.display_report_aggregates_only =
+      (FLAGS_benchmark_report_aggregates_only ||
+       FLAGS_benchmark_display_aggregates_only);
+  run_results.file_report_aggregates_only =
+      FLAGS_benchmark_report_aggregates_only;
+  if (b.aggregation_report_mode() != internal::ARM_Unspecified) {
+    run_results.display_report_aggregates_only =
+        (b.aggregation_report_mode() &
+         internal::ARM_DisplayReportAggregatesOnly);
+    run_results.file_report_aggregates_only =
+        (b.aggregation_report_mode() & internal::ARM_FileReportAggregatesOnly);
+    BM_CHECK(FLAGS_benchmark_perf_counters.empty() ||
+             (perf_counters_measurement_ptr->num_counters() == 0))
+        << "Perf counters were requested but could not be set up.";
+  }
+}
+
+BenchmarkRunner::IterationResults BenchmarkRunner::DoNIterations() {
+  BM_VLOG(2) << "Running " << b.name().str() << " for " << iters << "\n";
+
+  std::unique_ptr<internal::ThreadManager> manager;
+  manager.reset(new internal::ThreadManager(b.threads()));
+
+  // Run all but one thread in separate threads
+  for (std::size_t ti = 0; ti < pool.size(); ++ti) {
+    pool[ti] = std::thread(&RunInThread, &b, iters, static_cast<int>(ti + 1),
+                           manager.get(), perf_counters_measurement_ptr);
+  }
+  // And run one thread here directly.
+  // (If we were asked to run just one thread, we don't create new threads.)
+  // Yes, we need to do this here *after* we start the separate threads.
+  RunInThread(&b, iters, 0, manager.get(), perf_counters_measurement_ptr);
+
+  // The main thread has finished. Now let's wait for the other threads.
+  manager->WaitForAllThreads();
+  for (std::thread& thread : pool) thread.join();
+
+  IterationResults i;
+  // Acquire the measurements/counters from the manager, UNDER THE LOCK!
+  {
+    MutexLock l(manager->GetBenchmarkMutex());
+    i.results = manager->results;
+  }
+
+  // And get rid of the manager.
+  manager.reset();
+
+  // Adjust real/manual time stats since they were reported per thread.
+  i.results.real_time_used /= b.threads();
+  i.results.manual_time_used /= b.threads();
+  // If we were measuring whole-process CPU usage, adjust the CPU time too.
+  if (b.measure_process_cpu_time()) i.results.cpu_time_used /= b.threads();
+
+  BM_VLOG(2) << "Ran in " << i.results.cpu_time_used << "/"
+             << i.results.real_time_used << "\n";
+
+  // By using KeepRunningBatch a benchmark can iterate more times than
+  // requested, so take the iteration count from i.results.
+  i.iters = i.results.iterations / b.threads();
+
+  // Base decisions off of real time if requested by this benchmark.
+  i.seconds = i.results.cpu_time_used;
+  if (b.use_manual_time()) {
+    i.seconds = i.results.manual_time_used;
+  } else if (b.use_real_time()) {
+    i.seconds = i.results.real_time_used;
+  }
+
+  return i;
+}
+
+IterationCount BenchmarkRunner::PredictNumItersNeeded(
+    const IterationResults& i) const {
+  // See how much iterations should be increased by.
+  // Note: Avoid division by zero with max(seconds, 1ns).
+  double multiplier = GetMinTimeToApply() * 1.4 / std::max(i.seconds, 1e-9);
+  // If our last run was at least 10% of FLAGS_benchmark_min_time then we
+  // use the multiplier directly.
+  // Otherwise we use at most 10 times expansion.
+  // NOTE: When the last run was at least 10% of the min time the max
+  // expansion should be 14x.
+  const bool is_significant = (i.seconds / GetMinTimeToApply()) > 0.1;
+  multiplier = is_significant ? multiplier : 10.0;
+
+  // So what seems to be the sufficiently-large iteration count? Round up.
+  const IterationCount max_next_iters = static_cast<IterationCount>(
+      std::llround(std::max(multiplier * static_cast<double>(i.iters),
+                            static_cast<double>(i.iters) + 1.0)));
+  // But we do have *some* limits though..
+  const IterationCount next_iters = std::min(max_next_iters, kMaxIterations);
+
+  BM_VLOG(3) << "Next iters: " << next_iters << ", " << multiplier << "\n";
+  return next_iters;  // round up before conversion to integer.
+}
+
+bool BenchmarkRunner::ShouldReportIterationResults(
+    const IterationResults& i) const {
+  // Determine if this run should be reported;
+  // Either it has run for a sufficient amount of time
+  // or because an error was reported.
+  return i.results.skipped_ ||
+         i.iters >= kMaxIterations ||  // Too many iterations already.
+         i.seconds >=
+             GetMinTimeToApply() ||  // The elapsed time is large enough.
+         // CPU time is specified but the elapsed real time greatly exceeds
+         // the minimum time.
+         // Note that user provided timers are except from this test.
+         ((i.results.real_time_used >= 5 * GetMinTimeToApply()) &&
+          !b.use_manual_time());
+}
+
+double BenchmarkRunner::GetMinTimeToApply() const {
+  // In order to re-use functionality to run and measure benchmarks for running
+  // a warmup phase of the benchmark, we need a way of telling whether to apply
+  // min_time or min_warmup_time. This function will figure out if we are in the
+  // warmup phase and therefore need to apply min_warmup_time or if we already
+  // in the benchmarking phase and min_time needs to be applied.
+  return warmup_done ? min_time : min_warmup_time;
+}
+
+void BenchmarkRunner::FinishWarmUp(const IterationCount& i) {
+  warmup_done = true;
+  iters = i;
+}
+
+void BenchmarkRunner::RunWarmUp() {
+  // Use the same mechanisms for warming up the benchmark as used for actually
+  // running and measuring the benchmark.
+  IterationResults i_warmup;
+  // Dont use the iterations determined in the warmup phase for the actual
+  // measured benchmark phase. While this may be a good starting point for the
+  // benchmark and it would therefore get rid of the need to figure out how many
+  // iterations are needed if min_time is set again, this may also be a complete
+  // wrong guess since the warmup loops might be considerably slower (e.g
+  // because of caching effects).
+  const IterationCount i_backup = iters;
+
+  for (;;) {
+    b.Setup();
+    i_warmup = DoNIterations();
+    b.Teardown();
+
+    const bool finish = ShouldReportIterationResults(i_warmup);
+
+    if (finish) {
+      FinishWarmUp(i_backup);
+      break;
+    }
+
+    // Although we are running "only" a warmup phase where running enough
+    // iterations at once without measuring time isn't as important as it is for
+    // the benchmarking phase, we still do it the same way as otherwise it is
+    // very confusing for the user to know how to choose a proper value for
+    // min_warmup_time if a different approach on running it is used.
+    iters = PredictNumItersNeeded(i_warmup);
+    assert(iters > i_warmup.iters &&
+           "if we did more iterations than we want to do the next time, "
+           "then we should have accepted the current iteration run.");
+  }
+}
+
+void BenchmarkRunner::DoOneRepetition() {
+  assert(HasRepeatsRemaining() && "Already done all repetitions?");
+
+  const bool is_the_first_repetition = num_repetitions_done == 0;
+
+  // In case a warmup phase is requested by the benchmark, run it now.
+  // After running the warmup phase the BenchmarkRunner should be in a state as
+  // this warmup never happened except the fact that warmup_done is set. Every
+  // other manipulation of the BenchmarkRunner instance would be a bug! Please
+  // fix it.
+  if (!warmup_done) RunWarmUp();
+
+  IterationResults i;
+  // We *may* be gradually increasing the length (iteration count)
+  // of the benchmark until we decide the results are significant.
+  // And once we do, we report those last results and exit.
+  // Please do note that the if there are repetitions, the iteration count
+  // is *only* calculated for the *first* repetition, and other repetitions
+  // simply use that precomputed iteration count.
+  for (;;) {
+    b.Setup();
+    i = DoNIterations();
+    b.Teardown();
+
+    // Do we consider the results to be significant?
+    // If we are doing repetitions, and the first repetition was already done,
+    // it has calculated the correct iteration time, so we have run that very
+    // iteration count just now. No need to calculate anything. Just report.
+    // Else, the normal rules apply.
+    const bool results_are_significant = !is_the_first_repetition ||
+                                         has_explicit_iteration_count ||
+                                         ShouldReportIterationResults(i);
+
+    if (results_are_significant) break;  // Good, let's report them!
+
+    // Nope, bad iteration. Let's re-estimate the hopefully-sufficient
+    // iteration count, and run the benchmark again...
+
+    iters = PredictNumItersNeeded(i);
+    assert(iters > i.iters &&
+           "if we did more iterations than we want to do the next time, "
+           "then we should have accepted the current iteration run.");
+  }
+
+  // Oh, one last thing, we need to also produce the 'memory measurements'..
+  MemoryManager::Result* memory_result = nullptr;
+  IterationCount memory_iterations = 0;
+  if (memory_manager != nullptr) {
+    // TODO(vyng): Consider making BenchmarkReporter::Run::memory_result an
+    // optional so we don't have to own the Result here.
+    // Can't do it now due to cxx03.
+    memory_results.push_back(MemoryManager::Result());
+    memory_result = &memory_results.back();
+    // Only run a few iterations to reduce the impact of one-time
+    // allocations in benchmarks that are not properly managed.
+    memory_iterations = std::min<IterationCount>(16, iters);
+    memory_manager->Start();
+    std::unique_ptr<internal::ThreadManager> manager;
+    manager.reset(new internal::ThreadManager(1));
+    b.Setup();
+    RunInThread(&b, memory_iterations, 0, manager.get(),
+                perf_counters_measurement_ptr);
+    manager->WaitForAllThreads();
+    manager.reset();
+    b.Teardown();
+    memory_manager->Stop(*memory_result);
+  }
+
+  // Ok, now actually report.
+  BenchmarkReporter::Run report =
+      CreateRunReport(b, i.results, memory_iterations, memory_result, i.seconds,
+                      num_repetitions_done, repeats);
+
+  if (reports_for_family) {
+    ++reports_for_family->num_runs_done;
+    if (!report.skipped) reports_for_family->Runs.push_back(report);
+  }
+
+  run_results.non_aggregates.push_back(report);
+
+  ++num_repetitions_done;
+}
+
+RunResults&& BenchmarkRunner::GetResults() {
+  assert(!HasRepeatsRemaining() && "Did not run all repetitions yet?");
+
+  // Calculate additional statistics over the repetitions of this instance.
+  run_results.aggregates_only = ComputeStats(run_results.non_aggregates);
+
+  return std::move(run_results);
+}
+
+}  // end namespace internal
+
+}  // end namespace benchmark

third_party/benchmark/src/benchmark_runner.h

@@ -0,0 +1,131 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef BENCHMARK_RUNNER_H_
+#define BENCHMARK_RUNNER_H_
+
+#include <thread>
+#include <vector>
+
+#include "benchmark_api_internal.h"
+#include "internal_macros.h"
+#include "perf_counters.h"
+#include "thread_manager.h"
+
+namespace benchmark {
+
+BM_DECLARE_string(benchmark_min_time);
+BM_DECLARE_double(benchmark_min_warmup_time);
+BM_DECLARE_int32(benchmark_repetitions);
+BM_DECLARE_bool(benchmark_report_aggregates_only);
+BM_DECLARE_bool(benchmark_display_aggregates_only);
+BM_DECLARE_string(benchmark_perf_counters);
+
+namespace internal {
+
+extern MemoryManager* memory_manager;
+
+struct RunResults {
+  std::vector<BenchmarkReporter::Run> non_aggregates;
+  std::vector<BenchmarkReporter::Run> aggregates_only;
+
+  bool display_report_aggregates_only = false;
+  bool file_report_aggregates_only = false;
+};
+
+struct BENCHMARK_EXPORT BenchTimeType {
+  enum { ITERS, TIME } tag;
+  union {
+    IterationCount iters;
+    double time;
+  };
+};
+
+BENCHMARK_EXPORT
+BenchTimeType ParseBenchMinTime(const std::string& value);
+
+class BenchmarkRunner {
+ public:
+  BenchmarkRunner(const benchmark::internal::BenchmarkInstance& b_,
+                  benchmark::internal::PerfCountersMeasurement* pmc_,
+                  BenchmarkReporter::PerFamilyRunReports* reports_for_family);
+
+  int GetNumRepeats() const { return repeats; }
+
+  bool HasRepeatsRemaining() const {
+    return GetNumRepeats() != num_repetitions_done;
+  }
+
+  void DoOneRepetition();
+
+  RunResults&& GetResults();
+
+  BenchmarkReporter::PerFamilyRunReports* GetReportsForFamily() const {
+    return reports_for_family;
+  }
+
+  double GetMinTime() const { return min_time; }
+
+  bool HasExplicitIters() const { return has_explicit_iteration_count; }
+
+  IterationCount GetIters() const { return iters; }
+
+ private:
+  RunResults run_results;
+
+  const benchmark::internal::BenchmarkInstance& b;
+  BenchmarkReporter::PerFamilyRunReports* reports_for_family;
+
+  BenchTimeType parsed_benchtime_flag;
+  const double min_time;
+  const double min_warmup_time;
+  bool warmup_done;
+  const int repeats;
+  const bool has_explicit_iteration_count;
+
+  int num_repetitions_done = 0;
+
+  std::vector<std::thread> pool;
+
+  std::vector<MemoryManager::Result> memory_results;
+
+  IterationCount iters;  // preserved between repetitions!
+  // So only the first repetition has to find/calculate it,
+  // the other repetitions will just use that precomputed iteration count.
+
+  PerfCountersMeasurement* const perf_counters_measurement_ptr = nullptr;
+
+  struct IterationResults {
+    internal::ThreadManager::Result results;
+    IterationCount iters;
+    double seconds;
+  };
+  IterationResults DoNIterations();
+
+  IterationCount PredictNumItersNeeded(const IterationResults& i) const;
+
+  bool ShouldReportIterationResults(const IterationResults& i) const;
+
+  double GetMinTimeToApply() const;
+
+  void FinishWarmUp(const IterationCount& i);
+
+  void RunWarmUp();
+};
+
+}  // namespace internal
+
+}  // end namespace benchmark
+
+#endif  // BENCHMARK_RUNNER_H_

third_party/benchmark/src/check.cc

@@ -0,0 +1,11 @@
+#include "check.h"
+
+namespace benchmark {
+namespace internal {
+
+static AbortHandlerT* handler = &std::abort;
+
+BENCHMARK_EXPORT AbortHandlerT*& GetAbortHandler() { return handler; }
+
+}  // namespace internal
+}  // namespace benchmark

third_party/benchmark/src/check.h

@@ -0,0 +1,106 @@
+#ifndef CHECK_H_
+#define CHECK_H_
+
+#include <cmath>
+#include <cstdlib>
+#include <ostream>
+
+#include "benchmark/export.h"
+#include "internal_macros.h"
+#include "log.h"
+
+#if defined(__GNUC__) || defined(__clang__)
+#define BENCHMARK_NOEXCEPT noexcept
+#define BENCHMARK_NOEXCEPT_OP(x) noexcept(x)
+#elif defined(_MSC_VER) && !defined(__clang__)
+#if _MSC_VER >= 1900
+#define BENCHMARK_NOEXCEPT noexcept
+#define BENCHMARK_NOEXCEPT_OP(x) noexcept(x)
+#else
+#define BENCHMARK_NOEXCEPT
+#define BENCHMARK_NOEXCEPT_OP(x)
+#endif
+#define __func__ __FUNCTION__
+#else
+#define BENCHMARK_NOEXCEPT
+#define BENCHMARK_NOEXCEPT_OP(x)
+#endif
+
+namespace benchmark {
+namespace internal {
+
+typedef void(AbortHandlerT)();
+
+BENCHMARK_EXPORT
+AbortHandlerT*& GetAbortHandler();
+
+BENCHMARK_NORETURN inline void CallAbortHandler() {
+  GetAbortHandler()();
+  std::abort();  // fallback to enforce noreturn
+}
+
+// CheckHandler is the class constructed by failing BM_CHECK macros.
+// CheckHandler will log information about the failures and abort when it is
+// destructed.
+class CheckHandler {
+ public:
+  CheckHandler(const char* check, const char* file, const char* func, int line)
+      : log_(GetErrorLogInstance()) {
+    log_ << file << ":" << line << ": " << func << ": Check `" << check
+         << "' failed. ";
+  }
+
+  LogType& GetLog() { return log_; }
+
+#if defined(COMPILER_MSVC)
+#pragma warning(push)
+#pragma warning(disable : 4722)
+#endif
+  BENCHMARK_NORETURN ~CheckHandler() BENCHMARK_NOEXCEPT_OP(false) {
+    log_ << std::endl;
+    CallAbortHandler();
+  }
+#if defined(COMPILER_MSVC)
+#pragma warning(pop)
+#endif
+
+  CheckHandler& operator=(const CheckHandler&) = delete;
+  CheckHandler(const CheckHandler&) = delete;
+  CheckHandler() = delete;
+
+ private:
+  LogType& log_;
+};
+
+}  // end namespace internal
+}  // end namespace benchmark
+
+// The BM_CHECK macro returns a std::ostream object that can have extra
+// information written to it.
+#ifndef NDEBUG
+#define BM_CHECK(b)                                                          \
+  (b ? ::benchmark::internal::GetNullLogInstance()                           \
+     : ::benchmark::internal::CheckHandler(#b, __FILE__, __func__, __LINE__) \
+           .GetLog())
+#else
+#define BM_CHECK(b) ::benchmark::internal::GetNullLogInstance()
+#endif
+
+// clang-format off
+// preserve whitespacing between operators for alignment
+#define BM_CHECK_EQ(a, b) BM_CHECK((a) == (b))
+#define BM_CHECK_NE(a, b) BM_CHECK((a) != (b))
+#define BM_CHECK_GE(a, b) BM_CHECK((a) >= (b))
+#define BM_CHECK_LE(a, b) BM_CHECK((a) <= (b))
+#define BM_CHECK_GT(a, b) BM_CHECK((a) > (b))
+#define BM_CHECK_LT(a, b) BM_CHECK((a) < (b))
+
+#define BM_CHECK_FLOAT_EQ(a, b, eps) BM_CHECK(std::fabs((a) - (b)) <  (eps))
+#define BM_CHECK_FLOAT_NE(a, b, eps) BM_CHECK(std::fabs((a) - (b)) >= (eps))
+#define BM_CHECK_FLOAT_GE(a, b, eps) BM_CHECK((a) - (b) > -(eps))
+#define BM_CHECK_FLOAT_LE(a, b, eps) BM_CHECK((b) - (a) > -(eps))
+#define BM_CHECK_FLOAT_GT(a, b, eps) BM_CHECK((a) - (b) >  (eps))
+#define BM_CHECK_FLOAT_LT(a, b, eps) BM_CHECK((b) - (a) >  (eps))
+//clang-format on
+
+#endif  // CHECK_H_

third_party/benchmark/src/colorprint.cc

@@ -0,0 +1,200 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "colorprint.h"
+
+#include <cstdarg>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <memory>
+#include <string>
+
+#include "check.h"
+#include "internal_macros.h"
+
+#ifdef BENCHMARK_OS_WINDOWS
+#include <io.h>
+#include <windows.h>
+#else
+#include <unistd.h>
+#endif  // BENCHMARK_OS_WINDOWS
+
+namespace benchmark {
+namespace {
+#ifdef BENCHMARK_OS_WINDOWS
+typedef WORD PlatformColorCode;
+#else
+typedef const char* PlatformColorCode;
+#endif
+
+PlatformColorCode GetPlatformColorCode(LogColor color) {
+#ifdef BENCHMARK_OS_WINDOWS
+  switch (color) {
+    case COLOR_RED:
+      return FOREGROUND_RED;
+    case COLOR_GREEN:
+      return FOREGROUND_GREEN;
+    case COLOR_YELLOW:
+      return FOREGROUND_RED | FOREGROUND_GREEN;
+    case COLOR_BLUE:
+      return FOREGROUND_BLUE;
+    case COLOR_MAGENTA:
+      return FOREGROUND_BLUE | FOREGROUND_RED;
+    case COLOR_CYAN:
+      return FOREGROUND_BLUE | FOREGROUND_GREEN;
+    case COLOR_WHITE:  // fall through to default
+    default:
+      return 0;
+  }
+#else
+  switch (color) {
+    case COLOR_RED:
+      return "1";
+    case COLOR_GREEN:
+      return "2";
+    case COLOR_YELLOW:
+      return "3";
+    case COLOR_BLUE:
+      return "4";
+    case COLOR_MAGENTA:
+      return "5";
+    case COLOR_CYAN:
+      return "6";
+    case COLOR_WHITE:
+      return "7";
+    default:
+      return nullptr;
+  };
+#endif
+}
+
+}  // end namespace
+
+std::string FormatString(const char* msg, va_list args) {
+  // we might need a second shot at this, so pre-emptivly make a copy
+  va_list args_cp;
+  va_copy(args_cp, args);
+
+  std::size_t size = 256;
+  char local_buff[256];
+  auto ret = vsnprintf(local_buff, size, msg, args_cp);
+
+  va_end(args_cp);
+
+  // currently there is no error handling for failure, so this is hack.
+  BM_CHECK(ret >= 0);
+
+  if (ret == 0) {  // handle empty expansion
+    return {};
+  }
+  if (static_cast<size_t>(ret) < size) {
+    return local_buff;
+  }
+  // we did not provide a long enough buffer on our first attempt.
+  size = static_cast<size_t>(ret) + 1;  // + 1 for the null byte
+  std::unique_ptr<char[]> buff(new char[size]);
+  ret = vsnprintf(buff.get(), size, msg, args);
+  BM_CHECK(ret > 0 && (static_cast<size_t>(ret)) < size);
+  return buff.get();
+}
+
+std::string FormatString(const char* msg, ...) {
+  va_list args;
+  va_start(args, msg);
+  auto tmp = FormatString(msg, args);
+  va_end(args);
+  return tmp;
+}
+
+void ColorPrintf(std::ostream& out, LogColor color, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  ColorPrintf(out, color, fmt, args);
+  va_end(args);
+}
+
+void ColorPrintf(std::ostream& out, LogColor color, const char* fmt,
+                 va_list args) {
+#ifdef BENCHMARK_OS_WINDOWS
+  ((void)out);  // suppress unused warning
+
+  const HANDLE stdout_handle = GetStdHandle(STD_OUTPUT_HANDLE);
+
+  // Gets the current text color.
+  CONSOLE_SCREEN_BUFFER_INFO buffer_info;
+  GetConsoleScreenBufferInfo(stdout_handle, &buffer_info);
+  const WORD old_color_attrs = buffer_info.wAttributes;
+
+  // We need to flush the stream buffers into the console before each
+  // SetConsoleTextAttribute call lest it affect the text that is already
+  // printed but has not yet reached the console.
+  out.flush();
+  SetConsoleTextAttribute(stdout_handle,
+                          GetPlatformColorCode(color) | FOREGROUND_INTENSITY);
+  out << FormatString(fmt, args);
+
+  out.flush();
+  // Restores the text color.
+  SetConsoleTextAttribute(stdout_handle, old_color_attrs);
+#else
+  const char* color_code = GetPlatformColorCode(color);
+  if (color_code) out << FormatString("\033[0;3%sm", color_code);
+  out << FormatString(fmt, args) << "\033[m";
+#endif
+}
+
+bool IsColorTerminal() {
+#if BENCHMARK_OS_WINDOWS
+  // On Windows the TERM variable is usually not set, but the
+  // console there does support colors.
+  return 0 != _isatty(_fileno(stdout));
+#else
+  // On non-Windows platforms, we rely on the TERM variable. This list of
+  // supported TERM values is copied from Google Test:
+  // <https://github.com/google/googletest/blob/v1.13.0/googletest/src/gtest.cc#L3225-L3259>.
+  const char* const SUPPORTED_TERM_VALUES[] = {
+      "xterm",
+      "xterm-color",
+      "xterm-256color",
+      "screen",
+      "screen-256color",
+      "tmux",
+      "tmux-256color",
+      "rxvt-unicode",
+      "rxvt-unicode-256color",
+      "linux",
+      "cygwin",
+      "xterm-kitty",
+      "alacritty",
+      "foot",
+      "foot-extra",
+      "wezterm",
+  };
+
+  const char* const term = getenv("TERM");
+
+  bool term_supports_color = false;
+  for (const char* candidate : SUPPORTED_TERM_VALUES) {
+    if (term && 0 == strcmp(term, candidate)) {
+      term_supports_color = true;
+      break;
+    }
+  }
+
+  return 0 != isatty(fileno(stdout)) && term_supports_color;
+#endif  // BENCHMARK_OS_WINDOWS
+}
+
+}  // end namespace benchmark

third_party/benchmark/src/colorprint.h

@@ -0,0 +1,33 @@
+#ifndef BENCHMARK_COLORPRINT_H_
+#define BENCHMARK_COLORPRINT_H_
+
+#include <cstdarg>
+#include <iostream>
+#include <string>
+
+namespace benchmark {
+enum LogColor {
+  COLOR_DEFAULT,
+  COLOR_RED,
+  COLOR_GREEN,
+  COLOR_YELLOW,
+  COLOR_BLUE,
+  COLOR_MAGENTA,
+  COLOR_CYAN,
+  COLOR_WHITE
+};
+
+std::string FormatString(const char* msg, va_list args);
+std::string FormatString(const char* msg, ...);
+
+void ColorPrintf(std::ostream& out, LogColor color, const char* fmt,
+                 va_list args);
+void ColorPrintf(std::ostream& out, LogColor color, const char* fmt, ...);
+
+// Returns true if stdout appears to be a terminal that supports colored
+// output, false otherwise.
+bool IsColorTerminal();
+
+}  // end namespace benchmark
+
+#endif  // BENCHMARK_COLORPRINT_H_

third_party/benchmark/src/commandlineflags.cc

@@ -0,0 +1,298 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "commandlineflags.h"
+
+#include <algorithm>
+#include <cctype>
+#include <cstdlib>
+#include <cstring>
+#include <iostream>
+#include <limits>
+#include <map>
+#include <utility>
+
+#include "../src/string_util.h"
+
+namespace benchmark {
+namespace {
+
+// Parses 'str' for a 32-bit signed integer.  If successful, writes
+// the result to *value and returns true; otherwise leaves *value
+// unchanged and returns false.
+bool ParseInt32(const std::string& src_text, const char* str, int32_t* value) {
+  // Parses the environment variable as a decimal integer.
+  char* end = nullptr;
+  const long long_value = strtol(str, &end, 10);  // NOLINT
+
+  // Has strtol() consumed all characters in the string?
+  if (*end != '\0') {
+    // No - an invalid character was encountered.
+    std::cerr << src_text << " is expected to be a 32-bit integer, "
+              << "but actually has value \"" << str << "\".\n";
+    return false;
+  }
+
+  // Is the parsed value in the range of an Int32?
+  const int32_t result = static_cast<int32_t>(long_value);
+  if (long_value == std::numeric_limits<long>::max() ||
+      long_value == std::numeric_limits<long>::min() ||
+      // The parsed value overflows as a long.  (strtol() returns
+      // LONG_MAX or LONG_MIN when the input overflows.)
+      result != long_value
+      // The parsed value overflows as an Int32.
+  ) {
+    std::cerr << src_text << " is expected to be a 32-bit integer, "
+              << "but actually has value \"" << str << "\", "
+              << "which overflows.\n";
+    return false;
+  }
+
+  *value = result;
+  return true;
+}
+
+// Parses 'str' for a double.  If successful, writes the result to *value and
+// returns true; otherwise leaves *value unchanged and returns false.
+bool ParseDouble(const std::string& src_text, const char* str, double* value) {
+  // Parses the environment variable as a decimal integer.
+  char* end = nullptr;
+  const double double_value = strtod(str, &end);  // NOLINT
+
+  // Has strtol() consumed all characters in the string?
+  if (*end != '\0') {
+    // No - an invalid character was encountered.
+    std::cerr << src_text << " is expected to be a double, "
+              << "but actually has value \"" << str << "\".\n";
+    return false;
+  }
+
+  *value = double_value;
+  return true;
+}
+
+// Parses 'str' into KV pairs. If successful, writes the result to *value and
+// returns true; otherwise leaves *value unchanged and returns false.
+bool ParseKvPairs(const std::string& src_text, const char* str,
+                  std::map<std::string, std::string>* value) {
+  std::map<std::string, std::string> kvs;
+  for (const auto& kvpair : StrSplit(str, ',')) {
+    const auto kv = StrSplit(kvpair, '=');
+    if (kv.size() != 2) {
+      std::cerr << src_text << " is expected to be a comma-separated list of "
+                << "<key>=<value> strings, but actually has value \"" << str
+                << "\".\n";
+      return false;
+    }
+    if (!kvs.emplace(kv[0], kv[1]).second) {
+      std::cerr << src_text << " is expected to contain unique keys but key \""
+                << kv[0] << "\" was repeated.\n";
+      return false;
+    }
+  }
+
+  *value = kvs;
+  return true;
+}
+
+// Returns the name of the environment variable corresponding to the
+// given flag.  For example, FlagToEnvVar("foo") will return
+// "BENCHMARK_FOO" in the open-source version.
+static std::string FlagToEnvVar(const char* flag) {
+  const std::string flag_str(flag);
+
+  std::string env_var;
+  for (size_t i = 0; i != flag_str.length(); ++i)
+    env_var += static_cast<char>(::toupper(flag_str.c_str()[i]));
+
+  return env_var;
+}
+
+}  // namespace
+
+BENCHMARK_EXPORT
+bool BoolFromEnv(const char* flag, bool default_val) {
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value_str = getenv(env_var.c_str());
+  return value_str == nullptr ? default_val : IsTruthyFlagValue(value_str);
+}
+
+BENCHMARK_EXPORT
+int32_t Int32FromEnv(const char* flag, int32_t default_val) {
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value_str = getenv(env_var.c_str());
+  int32_t value = default_val;
+  if (value_str == nullptr ||
+      !ParseInt32(std::string("Environment variable ") + env_var, value_str,
+                  &value)) {
+    return default_val;
+  }
+  return value;
+}
+
+BENCHMARK_EXPORT
+double DoubleFromEnv(const char* flag, double default_val) {
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value_str = getenv(env_var.c_str());
+  double value = default_val;
+  if (value_str == nullptr ||
+      !ParseDouble(std::string("Environment variable ") + env_var, value_str,
+                   &value)) {
+    return default_val;
+  }
+  return value;
+}
+
+BENCHMARK_EXPORT
+const char* StringFromEnv(const char* flag, const char* default_val) {
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value = getenv(env_var.c_str());
+  return value == nullptr ? default_val : value;
+}
+
+BENCHMARK_EXPORT
+std::map<std::string, std::string> KvPairsFromEnv(
+    const char* flag, std::map<std::string, std::string> default_val) {
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value_str = getenv(env_var.c_str());
+
+  if (value_str == nullptr) return default_val;
+
+  std::map<std::string, std::string> value;
+  if (!ParseKvPairs("Environment variable " + env_var, value_str, &value)) {
+    return default_val;
+  }
+  return value;
+}
+
+// Parses a string as a command line flag.  The string should have
+// the format "--flag=value".  When def_optional is true, the "=value"
+// part can be omitted.
+//
+// Returns the value of the flag, or nullptr if the parsing failed.
+const char* ParseFlagValue(const char* str, const char* flag,
+                           bool def_optional) {
+  // str and flag must not be nullptr.
+  if (str == nullptr || flag == nullptr) return nullptr;
+
+  // The flag must start with "--".
+  const std::string flag_str = std::string("--") + std::string(flag);
+  const size_t flag_len = flag_str.length();
+  if (strncmp(str, flag_str.c_str(), flag_len) != 0) return nullptr;
+
+  // Skips the flag name.
+  const char* flag_end = str + flag_len;
+
+  // When def_optional is true, it's OK to not have a "=value" part.
+  if (def_optional && (flag_end[0] == '\0')) return flag_end;
+
+  // If def_optional is true and there are more characters after the
+  // flag name, or if def_optional is false, there must be a '=' after
+  // the flag name.
+  if (flag_end[0] != '=') return nullptr;
+
+  // Returns the string after "=".
+  return flag_end + 1;
+}
+
+BENCHMARK_EXPORT
+bool ParseBoolFlag(const char* str, const char* flag, bool* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, true);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Converts the string value to a bool.
+  *value = IsTruthyFlagValue(value_str);
+  return true;
+}
+
+BENCHMARK_EXPORT
+bool ParseInt32Flag(const char* str, const char* flag, int32_t* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  return ParseInt32(std::string("The value of flag --") + flag, value_str,
+                    value);
+}
+
+BENCHMARK_EXPORT
+bool ParseDoubleFlag(const char* str, const char* flag, double* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  return ParseDouble(std::string("The value of flag --") + flag, value_str,
+                     value);
+}
+
+BENCHMARK_EXPORT
+bool ParseStringFlag(const char* str, const char* flag, std::string* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  *value = value_str;
+  return true;
+}
+
+BENCHMARK_EXPORT
+bool ParseKeyValueFlag(const char* str, const char* flag,
+                       std::map<std::string, std::string>* value) {
+  const char* const value_str = ParseFlagValue(str, flag, false);
+
+  if (value_str == nullptr) return false;
+
+  for (const auto& kvpair : StrSplit(value_str, ',')) {
+    const auto kv = StrSplit(kvpair, '=');
+    if (kv.size() != 2) return false;
+    value->emplace(kv[0], kv[1]);
+  }
+
+  return true;
+}
+
+BENCHMARK_EXPORT
+bool IsFlag(const char* str, const char* flag) {
+  return (ParseFlagValue(str, flag, true) != nullptr);
+}
+
+BENCHMARK_EXPORT
+bool IsTruthyFlagValue(const std::string& value) {
+  if (value.size() == 1) {
+    char v = value[0];
+    return isalnum(v) &&
+           !(v == '0' || v == 'f' || v == 'F' || v == 'n' || v == 'N');
+  }
+  if (!value.empty()) {
+    std::string value_lower(value);
+    std::transform(value_lower.begin(), value_lower.end(), value_lower.begin(),
+                   [](char c) { return static_cast<char>(::tolower(c)); });
+    return !(value_lower == "false" || value_lower == "no" ||
+             value_lower == "off");
+  }
+  return true;
+}
+
+}  // end namespace benchmark

third_party/benchmark/src/commandlineflags.h

@@ -0,0 +1,133 @@
+#ifndef BENCHMARK_COMMANDLINEFLAGS_H_
+#define BENCHMARK_COMMANDLINEFLAGS_H_
+
+#include <cstdint>
+#include <map>
+#include <string>
+
+#include "benchmark/export.h"
+
+// Macro for referencing flags.
+#define FLAG(name) FLAGS_##name
+
+// Macros for declaring flags.
+#define BM_DECLARE_bool(name) BENCHMARK_EXPORT extern bool FLAG(name)
+#define BM_DECLARE_int32(name) BENCHMARK_EXPORT extern int32_t FLAG(name)
+#define BM_DECLARE_double(name) BENCHMARK_EXPORT extern double FLAG(name)
+#define BM_DECLARE_string(name) BENCHMARK_EXPORT extern std::string FLAG(name)
+#define BM_DECLARE_kvpairs(name) \
+  BENCHMARK_EXPORT extern std::map<std::string, std::string> FLAG(name)
+
+// Macros for defining flags.
+#define BM_DEFINE_bool(name, default_val) \
+  BENCHMARK_EXPORT bool FLAG(name) = benchmark::BoolFromEnv(#name, default_val)
+#define BM_DEFINE_int32(name, default_val) \
+  BENCHMARK_EXPORT int32_t FLAG(name) =    \
+      benchmark::Int32FromEnv(#name, default_val)
+#define BM_DEFINE_double(name, default_val) \
+  BENCHMARK_EXPORT double FLAG(name) =      \
+      benchmark::DoubleFromEnv(#name, default_val)
+#define BM_DEFINE_string(name, default_val) \
+  BENCHMARK_EXPORT std::string FLAG(name) = \
+      benchmark::StringFromEnv(#name, default_val)
+#define BM_DEFINE_kvpairs(name, default_val)                       \
+  BENCHMARK_EXPORT std::map<std::string, std::string> FLAG(name) = \
+      benchmark::KvPairsFromEnv(#name, default_val)
+
+namespace benchmark {
+
+// Parses a bool from the environment variable corresponding to the given flag.
+//
+// If the variable exists, returns IsTruthyFlagValue() value;  if not,
+// returns the given default value.
+BENCHMARK_EXPORT
+bool BoolFromEnv(const char* flag, bool default_val);
+
+// Parses an Int32 from the environment variable corresponding to the given
+// flag.
+//
+// If the variable exists, returns ParseInt32() value;  if not, returns
+// the given default value.
+BENCHMARK_EXPORT
+int32_t Int32FromEnv(const char* flag, int32_t default_val);
+
+// Parses an Double from the environment variable corresponding to the given
+// flag.
+//
+// If the variable exists, returns ParseDouble();  if not, returns
+// the given default value.
+BENCHMARK_EXPORT
+double DoubleFromEnv(const char* flag, double default_val);
+
+// Parses a string from the environment variable corresponding to the given
+// flag.
+//
+// If variable exists, returns its value;  if not, returns
+// the given default value.
+BENCHMARK_EXPORT
+const char* StringFromEnv(const char* flag, const char* default_val);
+
+// Parses a set of kvpairs from the environment variable corresponding to the
+// given flag.
+//
+// If variable exists, returns its value;  if not, returns
+// the given default value.
+BENCHMARK_EXPORT
+std::map<std::string, std::string> KvPairsFromEnv(
+    const char* flag, std::map<std::string, std::string> default_val);
+
+// Parses a string for a bool flag, in the form of either
+// "--flag=value" or "--flag".
+//
+// In the former case, the value is taken as true if it passes IsTruthyValue().
+//
+// In the latter case, the value is taken as true.
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+BENCHMARK_EXPORT
+bool ParseBoolFlag(const char* str, const char* flag, bool* value);
+
+// Parses a string for an Int32 flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+BENCHMARK_EXPORT
+bool ParseInt32Flag(const char* str, const char* flag, int32_t* value);
+
+// Parses a string for a Double flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+BENCHMARK_EXPORT
+bool ParseDoubleFlag(const char* str, const char* flag, double* value);
+
+// Parses a string for a string flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+BENCHMARK_EXPORT
+bool ParseStringFlag(const char* str, const char* flag, std::string* value);
+
+// Parses a string for a kvpairs flag in the form "--flag=key=value,key=value"
+//
+// On success, stores the value of the flag in *value and returns true. On
+// failure returns false, though *value may have been mutated.
+BENCHMARK_EXPORT
+bool ParseKeyValueFlag(const char* str, const char* flag,
+                       std::map<std::string, std::string>* value);
+
+// Returns true if the string matches the flag.
+BENCHMARK_EXPORT
+bool IsFlag(const char* str, const char* flag);
+
+// Returns true unless value starts with one of: '0', 'f', 'F', 'n' or 'N', or
+// some non-alphanumeric character. Also returns false if the value matches
+// one of 'no', 'false', 'off' (case-insensitive). As a special case, also
+// returns true if value is the empty string.
+BENCHMARK_EXPORT
+bool IsTruthyFlagValue(const std::string& value);
+
+}  // end namespace benchmark
+
+#endif  // BENCHMARK_COMMANDLINEFLAGS_H_

third_party/benchmark/src/complexity.cc

@@ -0,0 +1,259 @@
+// Copyright 2016 Ismael Jimenez Martinez. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Source project : https://github.com/ismaelJimenez/cpp.leastsq
+// Adapted to be used with google benchmark
+
+#include "complexity.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include "benchmark/benchmark.h"
+#include "check.h"
+
+namespace benchmark {
+
+// Internal function to calculate the different scalability forms
+BigOFunc* FittingCurve(BigO complexity) {
+  static const double kLog2E = 1.44269504088896340736;
+  switch (complexity) {
+    case oN:
+      return [](IterationCount n) -> double { return static_cast<double>(n); };
+    case oNSquared:
+      return [](IterationCount n) -> double { return std::pow(n, 2); };
+    case oNCubed:
+      return [](IterationCount n) -> double { return std::pow(n, 3); };
+    case oLogN:
+      /* Note: can't use log2 because Android's GNU STL lacks it */
+      return [](IterationCount n) {
+        return kLog2E * std::log(static_cast<double>(n));
+      };
+    case oNLogN:
+      /* Note: can't use log2 because Android's GNU STL lacks it */
+      return [](IterationCount n) {
+        return kLog2E * static_cast<double>(n) *
+               std::log(static_cast<double>(n));
+      };
+    case o1:
+    default:
+      return [](IterationCount) { return 1.0; };
+  }
+}
+
+// Function to return an string for the calculated complexity
+std::string GetBigOString(BigO complexity) {
+  switch (complexity) {
+    case oN:
+      return "N";
+    case oNSquared:
+      return "N^2";
+    case oNCubed:
+      return "N^3";
+    case oLogN:
+      return "lgN";
+    case oNLogN:
+      return "NlgN";
+    case o1:
+      return "(1)";
+    default:
+      return "f(N)";
+  }
+}
+
+// Find the coefficient for the high-order term in the running time, by
+// minimizing the sum of squares of relative error, for the fitting curve
+// given by the lambda expression.
+//   - n             : Vector containing the size of the benchmark tests.
+//   - time          : Vector containing the times for the benchmark tests.
+//   - fitting_curve : lambda expression (e.g. [](ComplexityN n) {return n; };).
+
+// For a deeper explanation on the algorithm logic, please refer to
+// https://en.wikipedia.org/wiki/Least_squares#Least_squares,_regression_analysis_and_statistics
+
+LeastSq MinimalLeastSq(const std::vector<ComplexityN>& n,
+                       const std::vector<double>& time,
+                       BigOFunc* fitting_curve) {
+  double sigma_gn_squared = 0.0;
+  double sigma_time = 0.0;
+  double sigma_time_gn = 0.0;
+
+  // Calculate least square fitting parameter
+  for (size_t i = 0; i < n.size(); ++i) {
+    double gn_i = fitting_curve(n[i]);
+    sigma_gn_squared += gn_i * gn_i;
+    sigma_time += time[i];
+    sigma_time_gn += time[i] * gn_i;
+  }
+
+  LeastSq result;
+  result.complexity = oLambda;
+
+  // Calculate complexity.
+  result.coef = sigma_time_gn / sigma_gn_squared;
+
+  // Calculate RMS
+  double rms = 0.0;
+  for (size_t i = 0; i < n.size(); ++i) {
+    double fit = result.coef * fitting_curve(n[i]);
+    rms += std::pow((time[i] - fit), 2);
+  }
+
+  // Normalized RMS by the mean of the observed values
+  double mean = sigma_time / static_cast<double>(n.size());
+  result.rms = std::sqrt(rms / static_cast<double>(n.size())) / mean;
+
+  return result;
+}
+
+// Find the coefficient for the high-order term in the running time, by
+// minimizing the sum of squares of relative error.
+//   - n          : Vector containing the size of the benchmark tests.
+//   - time       : Vector containing the times for the benchmark tests.
+//   - complexity : If different than oAuto, the fitting curve will stick to
+//                  this one. If it is oAuto, it will be calculated the best
+//                  fitting curve.
+LeastSq MinimalLeastSq(const std::vector<ComplexityN>& n,
+                       const std::vector<double>& time, const BigO complexity) {
+  BM_CHECK_EQ(n.size(), time.size());
+  BM_CHECK_GE(n.size(), 2);  // Do not compute fitting curve is less than two
+                             // benchmark runs are given
+  BM_CHECK_NE(complexity, oNone);
+
+  LeastSq best_fit;
+
+  if (complexity == oAuto) {
+    std::vector<BigO> fit_curves = {oLogN, oN, oNLogN, oNSquared, oNCubed};
+
+    // Take o1 as default best fitting curve
+    best_fit = MinimalLeastSq(n, time, FittingCurve(o1));
+    best_fit.complexity = o1;
+
+    // Compute all possible fitting curves and stick to the best one
+    for (const auto& fit : fit_curves) {
+      LeastSq current_fit = MinimalLeastSq(n, time, FittingCurve(fit));
+      if (current_fit.rms < best_fit.rms) {
+        best_fit = current_fit;
+        best_fit.complexity = fit;
+      }
+    }
+  } else {
+    best_fit = MinimalLeastSq(n, time, FittingCurve(complexity));
+    best_fit.complexity = complexity;
+  }
+
+  return best_fit;
+}
+
+std::vector<BenchmarkReporter::Run> ComputeBigO(
+    const std::vector<BenchmarkReporter::Run>& reports) {
+  typedef BenchmarkReporter::Run Run;
+  std::vector<Run> results;
+
+  if (reports.size() < 2) return results;
+
+  // Accumulators.
+  std::vector<ComplexityN> n;
+  std::vector<double> real_time;
+  std::vector<double> cpu_time;
+
+  // Populate the accumulators.
+  for (const Run& run : reports) {
+    BM_CHECK_GT(run.complexity_n, 0)
+        << "Did you forget to call SetComplexityN?";
+    n.push_back(run.complexity_n);
+    real_time.push_back(run.real_accumulated_time /
+                        static_cast<double>(run.iterations));
+    cpu_time.push_back(run.cpu_accumulated_time /
+                       static_cast<double>(run.iterations));
+  }
+
+  LeastSq result_cpu;
+  LeastSq result_real;
+
+  if (reports[0].complexity == oLambda) {
+    result_cpu = MinimalLeastSq(n, cpu_time, reports[0].complexity_lambda);
+    result_real = MinimalLeastSq(n, real_time, reports[0].complexity_lambda);
+  } else {
+    const BigO* InitialBigO = &reports[0].complexity;
+    const bool use_real_time_for_initial_big_o =
+        reports[0].use_real_time_for_initial_big_o;
+    if (use_real_time_for_initial_big_o) {
+      result_real = MinimalLeastSq(n, real_time, *InitialBigO);
+      InitialBigO = &result_real.complexity;
+      // The Big-O complexity for CPU time must have the same Big-O function!
+    }
+    result_cpu = MinimalLeastSq(n, cpu_time, *InitialBigO);
+    InitialBigO = &result_cpu.complexity;
+    if (!use_real_time_for_initial_big_o) {
+      result_real = MinimalLeastSq(n, real_time, *InitialBigO);
+    }
+  }
+
+  // Drop the 'args' when reporting complexity.
+  auto run_name = reports[0].run_name;
+  run_name.args.clear();
+
+  // Get the data from the accumulator to BenchmarkReporter::Run's.
+  Run big_o;
+  big_o.run_name = run_name;
+  big_o.family_index = reports[0].family_index;
+  big_o.per_family_instance_index = reports[0].per_family_instance_index;
+  big_o.run_type = BenchmarkReporter::Run::RT_Aggregate;
+  big_o.repetitions = reports[0].repetitions;
+  big_o.repetition_index = Run::no_repetition_index;
+  big_o.threads = reports[0].threads;
+  big_o.aggregate_name = "BigO";
+  big_o.aggregate_unit = StatisticUnit::kTime;
+  big_o.report_label = reports[0].report_label;
+  big_o.iterations = 0;
+  big_o.real_accumulated_time = result_real.coef;
+  big_o.cpu_accumulated_time = result_cpu.coef;
+  big_o.report_big_o = true;
+  big_o.complexity = result_cpu.complexity;
+
+  // All the time results are reported after being multiplied by the
+  // time unit multiplier. But since RMS is a relative quantity it
+  // should not be multiplied at all. So, here, we _divide_ it by the
+  // multiplier so that when it is multiplied later the result is the
+  // correct one.
+  double multiplier = GetTimeUnitMultiplier(reports[0].time_unit);
+
+  // Only add label to mean/stddev if it is same for all runs
+  Run rms;
+  rms.run_name = run_name;
+  rms.family_index = reports[0].family_index;
+  rms.per_family_instance_index = reports[0].per_family_instance_index;
+  rms.run_type = BenchmarkReporter::Run::RT_Aggregate;
+  rms.aggregate_name = "RMS";
+  rms.aggregate_unit = StatisticUnit::kPercentage;
+  rms.report_label = big_o.report_label;
+  rms.iterations = 0;
+  rms.repetition_index = Run::no_repetition_index;
+  rms.repetitions = reports[0].repetitions;
+  rms.threads = reports[0].threads;
+  rms.real_accumulated_time = result_real.rms / multiplier;
+  rms.cpu_accumulated_time = result_cpu.rms / multiplier;
+  rms.report_rms = true;
+  rms.complexity = result_cpu.complexity;
+  // don't forget to keep the time unit, or we won't be able to
+  // recover the correct value.
+  rms.time_unit = reports[0].time_unit;
+
+  results.push_back(big_o);
+  results.push_back(rms);
+  return results;
+}
+
+}  // end namespace benchmark

third_party/benchmark/src/complexity.h

@@ -0,0 +1,55 @@
+// Copyright 2016 Ismael Jimenez Martinez. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Source project : https://github.com/ismaelJimenez/cpp.leastsq
+// Adapted to be used with google benchmark
+
+#ifndef COMPLEXITY_H_
+#define COMPLEXITY_H_
+
+#include <string>
+#include <vector>
+
+#include "benchmark/benchmark.h"
+
+namespace benchmark {
+
+// Return a vector containing the bigO and RMS information for the specified
+// list of reports. If 'reports.size() < 2' an empty vector is returned.
+std::vector<BenchmarkReporter::Run> ComputeBigO(
+    const std::vector<BenchmarkReporter::Run>& reports);
+
+// This data structure will contain the result returned by MinimalLeastSq
+//   - coef        : Estimated coefficient for the high-order term as
+//                   interpolated from data.
+//   - rms         : Normalized Root Mean Squared Error.
+//   - complexity  : Scalability form (e.g. oN, oNLogN). In case a scalability
+//                   form has been provided to MinimalLeastSq this will return
+//                   the same value. In case BigO::oAuto has been selected, this
+//                   parameter will return the best fitting curve detected.
+
+struct LeastSq {
+  LeastSq() : coef(0.0), rms(0.0), complexity(oNone) {}
+
+  double coef;
+  double rms;
+  BigO complexity;
+};
+
+// Function to return an string for the calculated complexity
+std::string GetBigOString(BigO complexity);
+
+}  // end namespace benchmark
+
+#endif  // COMPLEXITY_H_