external: import cpu_features library

Taken from https://github.com/google/cpu_features at revision 26133d3b620c2c27f31d571efd27371100f891e9
2018-06-21 07:21:23 +02:00 · 2018-06-21 07:21:23 +02:00 · 931aca28e3
commit 931aca28e3
parent 69e75c90e7
55 changed files with 5724 additions and 0 deletions
--- a/external/cpu_features/.clang-format
+++ b/external/cpu_features/.clang-format
@ -0,0 +1,4 @@
+---
+Language:        Cpp
+BasedOnStyle:  Google
+...
--- a/external/cpu_features/.gitignore
+++ b/external/cpu_features/.gitignore
@ -0,0 +1 @@
+cmake_build/
--- a/external/cpu_features/.travis.yml
+++ b/external/cpu_features/.travis.yml
@ -0,0 +1,91 @@
+language: c
+
+sudo: false
+
+cache:
+  directories:
+    - $HOME/cpu_features_archives
+
+matrix:
+  include:
+  - os: linux
+    compiler: gcc
+    env:
+      TOOLCHAIN=NATIVE
+      TARGET=native
+  - os: linux
+    compiler: clang
+    env:
+      TOOLCHAIN=NATIVE
+      TARGET=native
+  - os: osx
+    compiler: gcc
+    env:
+      TOOLCHAIN=NATIVE
+      TARGET=native
+  - os: osx
+    compiler: clang
+    env:
+      TOOLCHAIN=NATIVE
+      TARGET=native
+  - os: linux-ppc64le
+    compiler: gcc
+    env:
+      TOOLCHAIN=NATIVE
+      TARGET=native
+  - os: linux-ppc64le
+    compiler: clang
+    env:
+      TOOLCHAIN=NATIVE
+      TARGET=native
+  # Toolchains for little-endian, 64-bit ARMv8 for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=aarch64-linux-gnu
+      QEMU_ARCH=aarch64
+  # Toolchains for little-endian, hard-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=arm-linux-gnueabihf
+      QEMU_ARCH=arm
+  # Toolchains for little-endian, 32-bit ARMv8 for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=armv8l-linux-gnueabihf
+      QEMU_ARCH=arm
+  # Toolchains for little-endian, soft-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=arm-linux-gnueabi
+      QEMU_ARCH=arm
+  # Toolchains for big-endian, 64-bit ARMv8 for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=aarch64_be-linux-gnu
+      QEMU_ARCH=DISABLED
+  # Toolchains for big-endian, hard-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=armeb-linux-gnueabihf
+      QEMU_ARCH=DISABLED
+  # Toolchains for big-endian, soft-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+  - os: linux
+    env:
+      TOOLCHAIN=LINARO
+      TARGET=armeb-linux-gnueabi
+      QEMU_ARCH=DISABLED
+  - os: linux
+    env:
+      TOOLCHAIN=CODESCAPE
+      TARGET=mips-mti-linux-gnu
+      QEMU_ARCH=DISABLED
+
+script:
+  - cmake --version
+  - bash -e -x ./scripts/run_integration.sh
--- a/external/cpu_features/CMakeLists.txt
+++ b/external/cpu_features/CMakeLists.txt
@ -0,0 +1,165 @@
+cmake_minimum_required(VERSION 3.0)
+
+project(CpuFeatures VERSION 0.1.0)
+
+# Default Build Type to be Release
+if(NOT CMAKE_BUILD_TYPE)
+  set(CMAKE_BUILD_TYPE "Release" CACHE STRING
+      "Choose the type of build, options are: Debug Release RelWithDebInfo MinSizeRel."
+      FORCE)
+endif(NOT CMAKE_BUILD_TYPE)
+
+# BUILD_TESTING is a standard CMake variable, but we declare it here to make it
+# prominent in the GUI.
+option(BUILD_TESTING "Enable test (depends on googletest)." OFF)
+# BUILD_SHARED_LIBS is a standard CMake variable, but we declare it here to make
+# it prominent in the GUI.
+option(BUILD_SHARED_LIBS "Build library as shared." OFF)
+
+#
+# library : cpu_features
+#
+
+set(_HDRS
+  include/cpuinfo_aarch64.h
+  include/cpuinfo_arm.h
+  include/cpuinfo_mips.h
+  include/cpuinfo_ppc.h
+  include/cpuinfo_x86.h
+  include/cpu_features_macros.h
+)
+
+add_library(cpu_features
+  ${_HDRS}
+  include/internal/bit_utils.h
+  include/internal/linux_features_aggregator.h
+  include/internal/cpuid_x86.h
+  include/internal/filesystem.h
+  include/internal/hwcaps.h
+  include/internal/stack_line_reader.h
+  include/internal/string_view.h
+  include/cpu_features_macros.h
+  src/linux_features_aggregator.c
+  src/cpuid_x86_clang_gcc.c
+  src/cpuid_x86_msvc.c
+  src/cpuinfo_aarch64.c
+  src/cpuinfo_arm.c
+  src/cpuinfo_mips.c
+  src/cpuinfo_ppc.c
+  src/cpuinfo_x86.c
+  src/filesystem.c
+  src/hwcaps.c
+  src/stack_line_reader.c
+  src/string_view.c
+)
+
+target_include_directories(cpu_features
+  PUBLIC
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include/cpu_features>
+  PRIVATE
+  include/internal
+)
+set_target_properties(cpu_features PROPERTIES PUBLIC_HEADER "${_HDRS}")
+target_compile_definitions(cpu_features
+  PUBLIC STACK_LINE_READER_BUFFER_SIZE=1024)
+target_link_libraries(cpu_features PUBLIC ${CMAKE_DL_LIBS})
+
+# The use of shared libraries is discouraged.
+# For API / ABI compatibility reasons, it is recommended to build and use
+# cpu_features in a subdirectory of your project or as an embedded dependency.
+if(BUILD_SHARED_LIBS)
+  set_property(TARGET cpu_features PROPERTY POSITION_INDEPENDENT_CODE ON)
+endif()
+add_library(CpuFeature::cpu_features ALIAS cpu_features)
+
+#
+# program : list_cpu_features
+#
+
+add_executable(list_cpu_features src/utils/list_cpu_features.c)
+target_link_libraries(list_cpu_features PRIVATE cpu_features)
+add_executable(CpuFeature::list_cpu_features ALIAS list_cpu_features)
+
+#
+# tests
+#
+
+include(CTest)
+if(BUILD_TESTING)
+  # Automatically incorporate googletest into the CMake Project if target not
+  # found.
+  if(NOT TARGET gtest OR NOT TARGET gmock_main)
+    # Download and unpack googletest at configure time.
+    configure_file(
+      cmake/googletest.CMakeLists.txt.in
+      googletest-download/CMakeLists.txt
+    )
+
+    execute_process(
+      COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
+      RESULT_VARIABLE result
+      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/googletest-download)
+
+    if(result)
+      message(FATAL_ERROR "CMake step for googletest failed: ${result}")
+    endif()
+
+    execute_process(
+      COMMAND ${CMAKE_COMMAND} --build .
+      RESULT_VARIABLE result
+      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/googletest-download)
+
+    if(result)
+      message(FATAL_ERROR "Build step for googletest failed: ${result}")
+    endif()
+
+    # Prevent overriding the parent project's compiler/linker settings on
+    # Windows.
+    set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+
+    # Add googletest directly to our build. This defines the gtest and
+    # gtest_main targets.
+    add_subdirectory(${CMAKE_BINARY_DIR}/googletest-src
+                     ${CMAKE_BINARY_DIR}/googletest-build
+                     EXCLUDE_FROM_ALL)
+  endif()
+
+  add_subdirectory(test)
+endif()
+
+#
+# Install
+#
+
+include(GNUInstallDirs)
+install(TARGETS cpu_features list_cpu_features
+  EXPORT CpuFeaturesTargets
+  PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/cpu_features
+  ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+)
+install(EXPORT CpuFeaturesTargets
+  NAMESPACE CpuFeatures::
+  DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/CpuFeatures
+  COMPONENT Devel
+)
+include(CMakePackageConfigHelpers)
+configure_package_config_file(cmake/CpuFeaturesConfig.cmake.in
+  "${PROJECT_BINARY_DIR}/CpuFeaturesConfig.cmake"
+  INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/CpuFeatures"
+  NO_SET_AND_CHECK_MACRO
+  NO_CHECK_REQUIRED_COMPONENTS_MACRO
+)
+write_basic_package_version_file(
+  "${PROJECT_BINARY_DIR}/CpuFeaturesConfigVersion.cmake"
+  COMPATIBILITY SameMajorVersion
+)
+install(
+  FILES
+  "${PROJECT_BINARY_DIR}/CpuFeaturesConfig.cmake"
+  "${PROJECT_BINARY_DIR}/CpuFeaturesConfigVersion.cmake"
+  DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/CpuFeatures"
+  COMPONENT Devel
+)
--- a/external/cpu_features/CONTRIBUTING.md
+++ b/external/cpu_features/CONTRIBUTING.md
@ -0,0 +1,23 @@
+# How to Contribute
+
+We'd love to accept your patches and contributions to this project. There are
+just a few small guidelines you need to follow.
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution;
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+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.
+
+## Code reviews
+
+All submissions, including submissions by project members, require review. We
+use GitHub pull requests for this purpose. Consult
+[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
+information on using pull requests.
--- a/external/cpu_features/LICENSE
+++ b/external/cpu_features/LICENSE
@ -0,0 +1,202 @@
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--- a/external/cpu_features/README.md
+++ b/external/cpu_features/README.md
@ -0,0 +1,165 @@
+# cpu_features [![Build Status](https://travis-ci.org/google/cpu_features.svg?branch=master)](https://travis-ci.org/google/cpu_features) [![Build status](https://ci.appveyor.com/api/projects/status/46d1owsj7n8dsylq/branch/master?svg=true)](https://ci.appveyor.com/project/gchatelet/cpu-features/branch/master)
+
+A cross-platform C library to retrieve CPU features (such as available
+instructions) at runtime.
+
+## Table of Contents
+
+- [Design Rationale](#rationale)
+- [Code samples](#codesample)
+- [Running sample code](#usagesample)
+- [What's supported](#support)
+- [License](#license)
+- [Build with cmake](#cmake)
+
+<a name="rationale"></a>
+## Design Rationale
+
+-   **Simple to use.** See the snippets below for examples.
+-   **Extensible.** Easy to add missing features or architectures.
+-   **Compatible with old compilers** and available on many architectures so it
+    can be used widely. To ensure that cpu_features works on as many platforms
+    as possible, we implemented it in a highly portable version of C: C99.
+-   **Sandbox-compatible.** The library uses a variety of strategies to cope
+    with sandboxed environments or when `cpuid` is unavailable. This is useful
+    when running integration tests in hermetic environments.
+-   **Thread safe, no memory allocation, and raises no exceptions.**
+    cpu_features is suitable for implementing fundamental libc functions like
+    `malloc`, `memcpy`, and `memcmp`.
+-   **Unit tested.**
+
+<a name="codesample"></a>
+### Checking features at runtime
+
+Here's a simple example that executes a codepath if the CPU supports both the
+AES and the SSE4.2 instruction sets:
+
+```c
+#include "cpuinfo_x86.h"
+
+static const X86Features features = GetX86Info().features;
+
+void Compute(void) {
+  if (features.aes && features.sse4_2) {
+    // Run optimized code.
+  } else {
+    // Run standard code.
+  }
+}
+```
+
+### Caching for faster evaluation of complex checks
+
+If you wish, you can read all the features at once into a global variable, and
+then query for the specific features you care about. Below, we store all the ARM
+features and then check whether AES and NEON are supported.
+
+```c
+#include <stdbool.h>
+#include "cpuinfo_arm.h"
+
+static const ArmFeatures features = GetArmInfo().features;
+static const bool has_aes_and_neon = features.aes && features.neon;
+
+// use has_aes_and_neon.
+```
+
+This is a good approach to take if you're checking for combinations of features
+when using a compiler that is slow to extract individual bits from bit-packed
+structures.
+
+### Checking compile time flags
+
+The following code determines whether the compiler was told to use the AVX
+instruction set (e.g., `g++ -mavx`) and sets `has_avx` accordingly.
+
+```c
+#include <stdbool.h>
+#include "cpuinfo_x86.h"
+
+static const X86Features features = GetX86Info().features;
+static const bool has_avx = CPU_FEATURES_COMPILED_X86_AVX || features.avx;
+
+// use has_avx.
+```
+
+`CPU_FEATURES_COMPILED_X86_AVX` is set to 1 if the compiler was instructed to
+use AVX and 0 otherwise, combining compile time and runtime knowledge.
+
+### Rejecting poor hardware implementations based on microarchitecture
+
+On x86, the first incarnation of a feature in a microarchitecture might not be
+the most efficient (e.g. AVX on Sandy Bridge). We provide a function to retrieve
+the underlying microarchitecture so you can decide whether to use it.
+
+Below, `has_fast_avx` is set to 1 if the CPU supports the AVX instruction
+set&mdash;but only if it's not Sandy Bridge.
+
+```c
+#include <stdbool.h>
+#include "cpuinfo_x86.h"
+
+static const X86Info info = GetX86Info();
+static const X86Microarchitecture uarch = GetX86Microarchitecture(&info);
+static const bool has_fast_avx = info.features.avx && uarch != INTEL_SNB;
+
+// use has_fast_avx.
+```
+
+This feature is currently available only for x86 microarchitectures.
+
+<a name="usagesample"></a>
+### Running sample code
+
+Building `cpu_features` brings a small executable to test the library.
+
+```shell
+ % ./build/list_cpu_features
+arch            : x86
+brand           :        Intel(R) Xeon(R) CPU E5-1650 0 @ 3.20GHz
+family          :   6 (0x06)
+model           :  45 (0x2D)
+stepping        :   7 (0x07)
+uarch           : INTEL_SNB
+flags           : aes,avx,cx16,smx,sse4_1,sse4_2,ssse3
+```
+
+```shell
+% ./build/list_cpu_features --json
+{"arch":"x86","brand":"       Intel(R) Xeon(R) CPU E5-1650 0 @ 3.20GHz","family":6,"model":45,"stepping":7,"uarch":"INTEL_SNB","flags":["aes","avx","cx16","smx","sse4_1","sse4_2","ssse3"]}
+```
+
+<a name="support"></a>
+## What's supported
+
+|         | x86³ |   ARM   | AArch64 | MIPSel |  POWER  |
+|---------|:----:|:-------:|:-------:|:------:|:-------:|
+| Android | yes² |   yes¹  |   yes¹  |  yes¹  |   N/A   |
+| iOS     |  N/A | not yet | not yet |   N/A  |   N/A   |
+| Linux   | yes² |   yes¹  |   yes¹  |  yes¹  |   yes¹  |
+| MacOs   | yes² |   N/A   | not yet |   N/A  |    no   |
+| Windows | yes² | not yet | not yet |   N/A  |   N/A   |
+
+1.  **Features revealed from Linux.** We gather data from several sources
+    depending on availability:
+    +   from glibc's
+        [getauxval](https://www.gnu.org/software/libc/manual/html_node/Auxiliary-Vector.html)
+    +   by parsing `/proc/self/auxv`
+    +   by parsing `/proc/cpuinfo`
+2.  **Features revealed from CPU.** features are retrieved by using the `cpuid`
+    instruction.
+3.  **Microarchitecture detection.** On x86 some features are not always
+    implemented efficiently in hardware (e.g. AVX on Sandybridge). Exposing the
+    microarchitecture allows the client to reject particular microarchitectures.
+
+
+<a name="license"></a>
+## License
+
+The cpu_features library is licensed under the terms of the Apache license.
+See [LICENSE](LICENSE) for more information.
+
+<a name="cmake"></a>
+## Build with CMake
+
+Please check the [CMake build instructions](cmake/README.md).
--- a/external/cpu_features/WORKSPACE
+++ b/external/cpu_features/WORKSPACE
@ -0,0 +1,7 @@
+# ===== googletest =====
+
+git_repository(
+    name = "com_google_googletest",
+    remote = "https://github.com/google/googletest.git",
+    commit = "c3f65335b79f47b05629e79a54685d899bc53b93",
+)
--- a/external/cpu_features/appveyor.yml
+++ b/external/cpu_features/appveyor.yml
@ -0,0 +1,24 @@
+version: '{build}'
+shallow_clone: true
+
+platform: x64
+
+environment:
+  matrix:
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+    CMAKE_GENERATOR: "Visual Studio 15 2017 Win64"
+  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    CMAKE_GENERATOR: "Visual Studio 14 2015 Win64"
+
+matrix:
+  fast_finish: true
+
+before_build:
+  - cmake --version
+  - cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=ON -H. -Bcmake_build -G "%CMAKE_GENERATOR%"
+
+build_script:
+  - cmake --build cmake_build --config Debug --target ALL_BUILD
+
+test_script:
+  - cmake --build cmake_build --config Debug --target RUN_TESTS
--- a/external/cpu_features/cmake/CpuFeaturesConfig.cmake.in
+++ b/external/cpu_features/cmake/CpuFeaturesConfig.cmake.in
@ -0,0 +1,3 @@
+# CpuFeatures CMake configuration file
+
+include("${CMAKE_CURRENT_LIST_DIR}/CpuFeaturesTargets.cmake")
--- a/external/cpu_features/cmake/README.md
+++ b/external/cpu_features/cmake/README.md
@ -0,0 +1,28 @@
+# CMake build instructions
+
+## Recommended usage : Incorporating cpu_features into a CMake project
+
+  For API / ABI compatibility reasons, it is recommended to build and use
+  cpu_features in a subdirectory of your project or as an embedded dependency.
+
+  This is similar to the recommended usage of the googletest framework
+  ( https://github.com/google/googletest/blob/master/googletest/README.md )
+
+  Build and use step-by-step
+
+
+  1- Download cpu_features and copy it in a sub-directory in your project.
+      or add cpu_features as a git-submodule in your project
+
+  2- You can then use the cmake command `add_subdirectory()` to include
+     cpu_features directly and use the `cpu_features` target in your project.
+
+  3- Add the `cpu_features` target to the `target_link_libraries()` section of
+     your executable or of your library.
+
+## Enabling tests
+
+  CMake default options for cpu_features is Release built type with tests
+  disabled. To enable testing set cmake `BUILD_TESTING` variable to `ON`,
+  [.travis.yml](../.travis.yml) and [appveyor.yml](../appveyor.yml) have up to
+  date examples.
--- a/external/cpu_features/cmake/googletest.CMakeLists.txt.in
+++ b/external/cpu_features/cmake/googletest.CMakeLists.txt.in
@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 2.8.2)
+
+project(googletest-download NONE)
+
+include(ExternalProject)
+ExternalProject_Add(googletest
+  GIT_REPOSITORY    https://github.com/google/googletest.git
+  GIT_TAG           master
+  SOURCE_DIR        "${CMAKE_BINARY_DIR}/googletest-src"
+  BINARY_DIR        "${CMAKE_BINARY_DIR}/googletest-build"
+  CONFIGURE_COMMAND ""
+  BUILD_COMMAND     ""
+  INSTALL_COMMAND   ""
+  TEST_COMMAND      ""
+)
--- a/external/cpu_features/cmake/mips32-linux-gcc.cmake
+++ b/external/cpu_features/cmake/mips32-linux-gcc.cmake
@ -0,0 +1,34 @@
+set(CMAKE_SYSTEM_NAME "Linux")
+set(CMAKE_SYSTEM_PROCESSOR "mips32")
+
+if (ENABLE_DSPR2 AND ENABLE_MSA)
+  message(FATAL_ERROR "ENABLE_DSPR2 and ENABLE_MSA cannot be combined.")
+endif ()
+
+if (ENABLE_DSPR2)
+  set(HAVE_DSPR2            1 CACHE BOOL "" FORCE)
+  set(MIPS_CFLAGS           "-mdspr2")
+  set(MIPS_CXXFLAGS         "-mdspr2")
+elseif (ENABLE_MSA)
+  set(HAVE_MSA 1 CACHE BOOL "" FORCE)
+  set(MIPS_CFLAGS           "-mmsa")
+  set(MIPS_CXXFLAGS         "-mmsa")
+endif ()
+
+if ("${MIPS_CPU}" STREQUAL "")
+  set(MIPS_CFLAGS           "${MIPS_CFLAGS} -mips32r2")
+  set(MIPS_CXXFLAGS         "${MIPS_CXXFLAGS} -mips32r2")
+elseif ("${MIPS_CPU}" STREQUAL "p5600")
+  set(P56_FLAGS             "-mips32r5 -mload-store-pairs -msched-weight -mhard-float -mfp64")
+  set(MIPS_CFLAGS           "${MIPS_CFLAGS} ${P56_FLAGS}")
+  set(MIPS_CXXFLAGS         "${MIPS_CXXFLAGS} ${P56_FLAGS}")
+  set(CMAKE_EXE_LINKER_FLAGS  "-mfp64 ${CMAKE_EXE_LINKER_FLAGS}")
+endif ()
+
+set(CMAKE_C_COMPILER        ${CROSS}gcc)
+set(CMAKE_CXX_COMPILER      ${CROSS}g++)
+set(AS_EXECUTABLE           ${CROSS}as)
+set(CMAKE_C_COMPILER_ARG1   "-EL ${MIPS_CFLAGS}")
+set(CMAKE_CXX_COMPILER_ARG1 "-EL ${MIPS_CXXFLAGS}")
+
+set(THREADS_PTHREAD_ARG "2" CACHE STRING "Forcibly set by CMakeLists.txt." FORCE)
--- a/external/cpu_features/include/cpu_features_macros.h
+++ b/external/cpu_features/include/cpu_features_macros.h
@ -0,0 +1,125 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_CPU_FEATURES_MACROS_H_
+#define CPU_FEATURES_INCLUDE_CPU_FEATURES_MACROS_H_
+
+////////////////////////////////////////////////////////////////////////////////
+// Architectures
+////////////////////////////////////////////////////////////////////////////////
+
+#if ((defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \
+      defined(__x86_64__)) &&                                     \
+     !defined(__pnacl__) && !defined(__CLR_VER))
+#define CPU_FEATURES_ARCH_X86
+#endif
+
+#if (defined(__arm__) || defined(_M_ARM))
+#define CPU_FEATURES_ARCH_ARM
+#endif
+
+#if defined(__aarch64__)
+#define CPU_FEATURES_ARCH_AARCH64
+#endif
+
+#if (defined(CPU_FEATURES_ARCH_AARCH64) || defined(CPU_FEATURES_ARCH_ARM))
+#define CPU_FEATURES_ARCH_ANY_ARM
+#endif
+
+#if defined(__mips__)
+#define CPU_FEATURES_ARCH_MIPS
+#endif
+
+#if defined(__powerpc__)
+#define CPU_FEATURES_ARCH_PPC
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// Os
+////////////////////////////////////////////////////////////////////////////////
+
+#if defined(__linux__)
+#define CPU_FEATURES_OS_LINUX_OR_ANDROID
+#endif
+
+#if defined(__ANDROID__)
+#define CPU_FEATURES_OS_ANDROID
+#endif
+
+#if (defined(_WIN64) || defined(_WIN32))
+#define CPU_FEATURES_OS_WINDOWS
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// Compilers
+////////////////////////////////////////////////////////////////////////////////
+
+#if defined(__clang__)
+#define CPU_FEATURES_COMPILER_CLANG
+#endif
+
+#if defined(__GNUC__) && !defined(__clang__)
+#define CPU_FEATURES_COMPILER_GCC
+#endif
+
+#if defined(_MSC_VER)
+#define CPU_FEATURES_COMPILER_MSC
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// Cpp
+////////////////////////////////////////////////////////////////////////////////
+
+#if defined(__cplusplus)
+#define CPU_FEATURES_START_CPP_NAMESPACE \
+  namespace cpu_features {  \
+  extern "C" {
+#define CPU_FEATURES_END_CPP_NAMESPACE \
+  }                       \
+  }
+#else
+#define CPU_FEATURES_START_CPP_NAMESPACE
+#define CPU_FEATURES_END_CPP_NAMESPACE
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// Compiler flags
+////////////////////////////////////////////////////////////////////////////////
+
+// Use the following to check if a feature is known to be available at compile
+// time. See README.md for an example.
+#if defined(CPU_FEATURES_ARCH_X86)
+#define CPU_FEATURES_COMPILED_X86_AES defined(__AES__)
+#define CPU_FEATURES_COMPILED_X86_F16C defined(__F16C__)
+#define CPU_FEATURES_COMPILED_X86_BMI defined(__BMI__)
+#define CPU_FEATURES_COMPILED_X86_BMI2 defined(__BMI2__)
+#define CPU_FEATURES_COMPILED_X86_SSE (defined(__SSE__) || (_M_IX86_FP >= 1))
+#define CPU_FEATURES_COMPILED_X86_SSE2 (defined(__SSE2__) || (_M_IX86_FP >= 2))
+#define CPU_FEATURES_COMPILED_X86_SSE3 defined(__SSE3__)
+#define CPU_FEATURES_COMPILED_X86_SSSE3 defined(__SSSE3__)
+#define CPU_FEATURES_COMPILED_X86_SSE4_1 defined(__SSE4_1__)
+#define CPU_FEATURES_COMPILED_X86_SSE4_2 defined(__SSE4_2__)
+#define CPU_FEATURES_COMPILED_X86_AVX defined(__AVX__)
+#define CPU_FEATURES_COMPILED_x86_AVX2 defined(__AVX2__)
+#endif
+
+#if defined(CPU_FEATURES_ARCH_ANY_ARM)
+#define CPU_FEATURES_COMPILED_ANY_ARM_NEON defined(__ARM_NEON__)
+#endif
+
+#if defined(CPU_FEATURES_ARCH_MIPS)
+#define CPU_FEATURES_COMPILED_MIPS_MSA defined(__mips_msa)
+#endif
+
+#endif  // CPU_FEATURES_INCLUDE_CPU_FEATURES_MACROS_H_
--- a/external/cpu_features/include/cpuinfo_aarch64.h
+++ b/external/cpu_features/include/cpuinfo_aarch64.h
@ -0,0 +1,65 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_CPUINFO_AARCH64_H_
+#define CPU_FEATURES_INCLUDE_CPUINFO_AARCH64_H_
+
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+typedef struct {
+  int fp : 1;     // Floating-point.
+  int asimd : 1;  // Advanced SIMD.
+  int aes : 1;    // Hardware-accelerated Advanced Encryption Standard.
+  int pmull : 1;  // Polynomial multiply long.
+  int sha1 : 1;   // Hardware-accelerated SHA1.
+  int sha2 : 1;   // Hardware-accelerated SHA2-256.
+  int crc32 : 1;  // Hardware-accelerated CRC-32.
+
+  // Make sure to update Aarch64FeaturesEnum below if you add a field here.
+} Aarch64Features;
+
+typedef struct {
+  Aarch64Features features;
+  int implementer;
+  int variant;
+  int part;
+  int revision;
+} Aarch64Info;
+
+Aarch64Info GetAarch64Info(void);
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+typedef enum {
+  AARCH64_FP,
+  AARCH64_ASIMD,
+  AARCH64_AES,
+  AARCH64_PMULL,
+  AARCH64_SHA1,
+  AARCH64_SHA2,
+  AARCH64_CRC32,
+  AARCH64_LAST_,
+} Aarch64FeaturesEnum;
+
+int GetAarch64FeaturesEnumValue(const Aarch64Features* features,
+                                Aarch64FeaturesEnum value);
+
+const char* GetAarch64FeaturesEnumName(Aarch64FeaturesEnum);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_CPUINFO_AARCH64_H_
--- a/external/cpu_features/include/cpuinfo_arm.h
+++ b/external/cpu_features/include/cpuinfo_arm.h
@ -0,0 +1,80 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_CPUINFO_ARM_H_
+#define CPU_FEATURES_INCLUDE_CPUINFO_ARM_H_
+
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+typedef struct {
+  int vfp : 1;       // Vector Floating Point.
+  int iwmmxt : 1;    // Intel Wireless MMX Technology.
+  int neon : 1;      // Advanced SIMD.
+  int vfpv3 : 1;     // VFP version 3
+  int vfpv3d16 : 1;  // VFP version 3 with 16 D-registers
+  int vfpv4 : 1;     // VFP version 4 with fast context switching
+  int idiva : 1;     // SDIV and UDIV hardware division in ARM mode.
+  int idivt : 1;     // SDIV and UDIV hardware division in Thumb mode.
+  int aes : 1;       // Hardware-accelerated Advanced Encryption Standard.
+  int pmull : 1;     // Polynomial multiply long.
+  int sha1 : 1;      // Hardware-accelerated SHA1.
+  int sha2 : 1;      // Hardware-accelerated SHA2-256.
+  int crc32 : 1;     // Hardware-accelerated CRC-32.
+
+  // Make sure to update ArmFeaturesEnum below if you add a field here.
+} ArmFeatures;
+
+typedef struct {
+  ArmFeatures features;
+  int implementer;
+  int architecture;
+  int variant;
+  int part;
+  int revision;
+} ArmInfo;
+
+// TODO(user): Add macros to know which features are present at compile
+// time.
+
+ArmInfo GetArmInfo(void);
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+typedef enum {
+  ARM_VFP,
+  ARM_IWMMXT,
+  ARM_NEON,
+  ARM_VFPV3,
+  ARM_VFPV3D16,
+  ARM_VFPV4,
+  ARM_IDIVA,
+  ARM_IDIVT,
+  ARM_AES,
+  ARM_PMULL,
+  ARM_SHA1,
+  ARM_SHA2,
+  ARM_CRC32,
+  ARM_LAST_,
+} ArmFeaturesEnum;
+
+int GetArmFeaturesEnumValue(const ArmFeatures* features, ArmFeaturesEnum value);
+
+const char* GetArmFeaturesEnumName(ArmFeaturesEnum);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_CPUINFO_ARM_H_
--- a/external/cpu_features/include/cpuinfo_mips.h
+++ b/external/cpu_features/include/cpuinfo_mips.h
@ -0,0 +1,53 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_CPUINFO_MIPS_H_
+#define CPU_FEATURES_INCLUDE_CPUINFO_MIPS_H_
+
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+typedef struct {
+  int msa : 1;  // MIPS SIMD Architecture
+                // https://www.mips.com/products/architectures/ase/simd/
+  int eva : 1;  // Enhanced Virtual Addressing
+                // https://www.mips.com/products/architectures/mips64/
+
+  // Make sure to update MipsFeaturesEnum below if you add a field here.
+} MipsFeatures;
+
+typedef struct {
+  MipsFeatures features;
+} MipsInfo;
+
+MipsInfo GetMipsInfo(void);
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+typedef enum {
+  MIPS_MSA,
+  MIPS_EVA,
+  MIPS_LAST_,
+} MipsFeaturesEnum;
+
+int GetMipsFeaturesEnumValue(const MipsFeatures* features,
+                             MipsFeaturesEnum value);
+
+const char* GetMipsFeaturesEnumName(MipsFeaturesEnum);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_CPUINFO_MIPS_H_
--- a/external/cpu_features/include/cpuinfo_ppc.h
+++ b/external/cpu_features/include/cpuinfo_ppc.h
@ -0,0 +1,141 @@
+// Copyright 2018 IBM
+//
+// 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 CPU_FEATURES_INCLUDE_CPUINFO_PPC_H_
+#define CPU_FEATURES_INCLUDE_CPUINFO_PPC_H_
+
+#include "cpu_features_macros.h"
+#include "internal/hwcaps.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+typedef struct {
+  int ppc32 : 1;
+  int ppc64 : 1;
+  int ppc601 : 1;
+  int altivec : 1;
+  int fpu : 1;
+  int mmu : 1;
+  int mac_4xx : 1;
+  int unifiedcache : 1;
+  int spe : 1;
+  int efpsingle : 1;
+  int efpdouble : 1;
+  int no_tb : 1;
+  int power4 : 1;
+  int power5 : 1;
+  int power5plus : 1;
+  int cell : 1;
+  int booke : 1;
+  int smt : 1;
+  int icachesnoop : 1;
+  int arch205 : 1;
+  int pa6t : 1;
+  int dfp : 1;
+  int power6ext : 1;
+  int arch206 : 1;
+  int vsx : 1;
+  int pseries_perfmon_compat : 1;
+  int truele : 1;
+  int ppcle : 1;
+  int arch207 : 1;
+  int htm : 1;
+  int dscr : 1;
+  int ebb : 1;
+  int isel : 1;
+  int tar : 1;
+  int vcrypto : 1;
+  int htm_nosc : 1;
+  int arch300 : 1;
+  int ieee128 : 1;
+  int darn : 1;
+  int scv : 1;
+  int htm_no_suspend : 1;
+
+  // Make sure to update PPCFeaturesEnum below if you add a field here.
+} PPCFeatures;
+
+typedef struct {
+  PPCFeatures features;
+} PPCInfo;
+
+// This function is guaranteed to be malloc, memset and memcpy free.
+PPCInfo GetPPCInfo(void);
+
+typedef struct {
+  char platform[64];  // 0 terminated string
+  char model[64];     // 0 terminated string
+  char machine[64];   // 0 terminated string
+  char cpu[64];       // 0 terminated string
+  PlatformType type;
+} PPCPlatformStrings;
+
+PPCPlatformStrings GetPPCPlatformStrings(void);
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+typedef enum {
+  PPC_32,          /* 32 bit mode execution */
+  PPC_64,          /* 64 bit mode execution */
+  PPC_601_INSTR,   /* Old POWER ISA */
+  PPC_HAS_ALTIVEC, /* SIMD Unit*/
+  PPC_HAS_FPU,     /* Floating Point Unit */
+  PPC_HAS_MMU,     /* Memory management unit */
+  PPC_HAS_4xxMAC,
+  PPC_UNIFIED_CACHE,  /* Unified instruction and data cache */
+  PPC_HAS_SPE,        /* Signal processing extention unit */
+  PPC_HAS_EFP_SINGLE, /* SPE single precision fpu */
+  PPC_HAS_EFP_DOUBLE, /* SPE double precision fpu */
+  PPC_NO_TB,          /* No timebase */
+  PPC_POWER4,
+  PPC_POWER5,
+  PPC_POWER5_PLUS,
+  PPC_CELL,  /* Cell broadband engine */
+  PPC_BOOKE, /* Embedded ISA */
+  PPC_SMT,   /* Simultaneous multi-threading */
+  PPC_ICACHE_SNOOP,
+  PPC_ARCH_2_05, /* ISA 2.05 - POWER6 */
+  PPC_PA6T,      /* PA Semi 6T core ISA */
+  PPC_HAS_DFP,   /* Decimal floating point unit */
+  PPC_POWER6_EXT,
+  PPC_ARCH_2_06,              /* ISA 2.06 - POWER7 */
+  PPC_HAS_VSX,                /* Vector-scalar extension */
+  PPC_PSERIES_PERFMON_COMPAT, /* Set of backwards compatibile performance
+                                 monitoring events */
+  PPC_TRUE_LE,
+  PPC_PPC_LE,
+  PPC_ARCH_2_07,      /* ISA 2.07 - POWER8 */
+  PPC_HTM,            /* Hardware Transactional Memory */
+  PPC_DSCR,           /* Data stream control register */
+  PPC_EBB,            /* Event base branching */
+  PPC_ISEL,           /* Integer select instructions */
+  PPC_TAR,            /* Target address register */
+  PPC_VEC_CRYPTO,     /* Vector cryptography instructions */
+  PPC_HTM_NOSC,       /* Transactions aborted when syscall made*/
+  PPC_ARCH_3_00,      /* ISA 3.00 - POWER9 */
+  PPC_HAS_IEEE128,    /* VSX IEEE Binary Float 128-bit */
+  PPC_DARN,           /* Deliver a random number instruction */
+  PPC_SCV,            /* scv syscall */
+  PPC_HTM_NO_SUSPEND, /* TM w/out suspended state */
+  PPC_LAST_,
+} PPCFeaturesEnum;
+
+int GetPPCFeaturesEnumValue(const PPCFeatures* features, PPCFeaturesEnum value);
+
+const char* GetPPCFeaturesEnumName(PPCFeaturesEnum);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_CPUINFO_PPC_H_
--- a/external/cpu_features/include/cpuinfo_x86.h
+++ b/external/cpu_features/include/cpuinfo_x86.h
@ -0,0 +1,154 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_CPUINFO_X86_H_
+#define CPU_FEATURES_INCLUDE_CPUINFO_X86_H_
+
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+// See https://en.wikipedia.org/wiki/CPUID for a list of x86 cpu features.
+typedef struct {
+  int aes : 1;
+  int erms : 1;
+  int f16c : 1;
+  int fma3 : 1;
+  int vpclmulqdq : 1;
+  int bmi1 : 1;
+  int bmi2 : 1;
+
+  int ssse3 : 1;
+  int sse4_1 : 1;
+  int sse4_2 : 1;
+
+  int avx : 1;
+  int avx2 : 1;
+
+  int avx512f : 1;
+  int avx512cd : 1;
+  int avx512er : 1;
+  int avx512pf : 1;
+  int avx512bw : 1;
+  int avx512dq : 1;
+  int avx512vl : 1;
+  int avx512ifma : 1;
+  int avx512vbmi : 1;
+  int avx512vbmi2 : 1;
+  int avx512vnni : 1;
+  int avx512bitalg : 1;
+  int avx512vpopcntdq : 1;
+  int avx512_4vnniw : 1;
+  int avx512_4vbmi2 : 1;
+
+  int smx : 1;
+  int sgx : 1;
+  int cx16 : 1;  // aka. CMPXCHG16B
+
+  // Make sure to update X86FeaturesEnum below if you add a field here.
+} X86Features;
+
+typedef struct {
+  X86Features features;
+  int family;
+  int model;
+  int stepping;
+  char vendor[13];  // 0 terminated string
+} X86Info;
+
+// Calls cpuid and returns an initialized X86info.
+// This function is guaranteed to be malloc, memset and memcpy free.
+X86Info GetX86Info(void);
+
+typedef enum {
+  X86_UNKNOWN,
+  INTEL_CORE,      // CORE
+  INTEL_PNR,       // PENRYN
+  INTEL_NHM,       // NEHALEM
+  INTEL_ATOM_BNL,  // BONNELL
+  INTEL_WSM,       // WESTMERE
+  INTEL_SNB,       // SANDYBRIDGE
+  INTEL_IVB,       // IVYBRIDGE
+  INTEL_ATOM_SMT,  // SILVERMONT
+  INTEL_HSW,       // HASWELL
+  INTEL_BDW,       // BROADWELL
+  INTEL_SKL,       // SKYLAKE
+  INTEL_ATOM_GMT,  // GOLDMONT
+  INTEL_KBL,       // KABY LAKE
+  INTEL_CFL,       // COFFEE LAKE
+  INTEL_CNL,       // CANNON LAKE
+  AMD_HAMMER,      // K8
+  AMD_K10,         // K10
+  AMD_BOBCAT,      // K14
+  AMD_BULLDOZER,   // K15
+  AMD_JAGUAR,      // K16
+  AMD_ZEN,         // K17
+} X86Microarchitecture;
+
+// Returns the underlying microarchitecture by looking at X86Info's vendor,
+// family and model.
+X86Microarchitecture GetX86Microarchitecture(const X86Info* info);
+
+// Calls cpuid and fills the brand_string.
+// - brand_string *must* be of size 49 (beware of array decaying).
+// - brand_string will be zero terminated.
+// - This function calls memcpy.
+void FillX86BrandString(char brand_string[49]);
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+typedef enum {
+  X86_AES,
+  X86_ERMS,
+  X86_F16C,
+  X86_FMA3,
+  X86_VPCLMULQDQ,
+  X86_BMI1,
+  X86_BMI2,
+  X86_SSSE3,
+  X86_SSE4_1,
+  X86_SSE4_2,
+  X86_AVX,
+  X86_AVX2,
+  X86_AVX512F,
+  X86_AVX512CD,
+  X86_AVX512ER,
+  X86_AVX512PF,
+  X86_AVX512BW,
+  X86_AVX512DQ,
+  X86_AVX512VL,
+  X86_AVX512IFMA,
+  X86_AVX512VBMI,
+  X86_AVX512VBMI2,
+  X86_AVX512VNNI,
+  X86_AVX512BITALG,
+  X86_AVX512VPOPCNTDQ,
+  X86_AVX512_4VNNIW,
+  X86_AVX512_4VBMI2,
+  X86_SMX,
+  X86_SGX,
+  X86_CX16,
+  X86_LAST_,
+} X86FeaturesEnum;
+
+int GetX86FeaturesEnumValue(const X86Features* features, X86FeaturesEnum value);
+
+const char* GetX86FeaturesEnumName(X86FeaturesEnum);
+
+const char* GetX86MicroarchitectureName(X86Microarchitecture);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_CPUINFO_X86_H_
--- a/external/cpu_features/include/internal/bit_utils.h
+++ b/external/cpu_features/include/internal/bit_utils.h
@ -0,0 +1,39 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_INTERNAL_BIT_UTILS_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_BIT_UTILS_H_
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+inline static bool IsBitSet(uint32_t reg, uint32_t bit) {
+  return (reg >> bit) & 0x1;
+}
+
+inline static uint32_t ExtractBitRange(uint32_t reg, uint32_t msb,
+                                       uint32_t lsb) {
+  const uint64_t bits = msb - lsb + 1;
+  const uint64_t mask = (1ULL << bits) - 1ULL;
+  assert(msb >= lsb);
+  return (reg >> lsb) & mask;
+}
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_BIT_UTILS_H_
--- a/external/cpu_features/include/internal/cpuid_x86.h
+++ b/external/cpu_features/include/internal/cpuid_x86.h
@ -0,0 +1,37 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_INCLUDE_INTERNAL_CPUID_X86_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_CPUID_X86_H_
+
+#include <stdint.h>
+
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+// A struct to hold the result of a call to cpuid.
+typedef struct {
+  uint32_t eax, ebx, ecx, edx;
+} Leaf;
+
+// Retrieves the leaf for a particular cpuid.
+Leaf CpuId(uint32_t leaf_id);
+
+// Returns the eax value of the XCR0 register.
+uint32_t GetXCR0Eax(void);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_CPUID_X86_H_
--- a/external/cpu_features/include/internal/filesystem.h
+++ b/external/cpu_features/include/internal/filesystem.h
@ -0,0 +1,38 @@
+// Copyright 2017 Google Inc.
+//
+// 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.
+
+// An interface for the filesystem that allows mocking the filesystem in
+// unittests.
+#ifndef CPU_FEATURES_INCLUDE_INTERNAL_FILESYSTEM_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_FILESYSTEM_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+// Same as linux "open(filename, O_RDONLY)", retries automatically on EINTR.
+int CpuFeatures_OpenFile(const char* filename);
+
+// Same as linux "read(file_descriptor, buffer, buffer_size)", retries
+// automatically on EINTR.
+int CpuFeatures_ReadFile(int file_descriptor, void* buffer, size_t buffer_size);
+
+// Same as linux "close(file_descriptor)".
+void CpuFeatures_CloseFile(int file_descriptor);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_FILESYSTEM_H_
--- a/external/cpu_features/include/internal/hwcaps.h
+++ b/external/cpu_features/include/internal/hwcaps.h
@ -0,0 +1,131 @@
+// Copyright 2017 Google Inc.
+//
+// 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.
+
+// Interface to retrieve hardware capabilities. It relies on Linux's getauxval
+// or `/proc/self/auxval` under the hood.
+#ifndef CPU_FEATURES_INCLUDE_INTERNAL_HWCAPS_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_HWCAPS_H_
+
+#include <stdint.h>
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+// To avoid depending on the linux kernel we reproduce the architecture specific
+// constants here.
+
+// http://elixir.free-electrons.com/linux/latest/source/arch/arm64/include/uapi/asm/hwcap.h
+#define AARCH64_HWCAP_FP (1UL << 0)
+#define AARCH64_HWCAP_ASIMD (1UL << 1)
+#define AARCH64_HWCAP_AES (1UL << 3)
+#define AARCH64_HWCAP_PMULL (1UL << 4)
+#define AARCH64_HWCAP_SHA1 (1UL << 5)
+#define AARCH64_HWCAP_SHA2 (1UL << 6)
+#define AARCH64_HWCAP_CRC32 (1UL << 7)
+
+// http://elixir.free-electrons.com/linux/latest/source/arch/arm/include/uapi/asm/hwcap.h
+#define ARM_HWCAP_VFP (1UL << 6)
+#define ARM_HWCAP_IWMMXT (1UL << 9)
+#define ARM_HWCAP_NEON (1UL << 12)
+#define ARM_HWCAP_VFPV3 (1UL << 13)
+#define ARM_HWCAP_VFPV3D16 (1UL << 14)
+#define ARM_HWCAP_VFPV4 (1UL << 16)
+#define ARM_HWCAP_IDIVA (1UL << 17)
+#define ARM_HWCAP_IDIVT (1UL << 18)
+#define ARM_HWCAP2_AES (1UL << 0)
+#define ARM_HWCAP2_PMULL (1UL << 1)
+#define ARM_HWCAP2_SHA1 (1UL << 2)
+#define ARM_HWCAP2_SHA2 (1UL << 3)
+#define ARM_HWCAP2_CRC32 (1UL << 4)
+
+// http://elixir.free-electrons.com/linux/latest/source/arch/mips/include/uapi/asm/hwcap.h
+#define MIPS_HWCAP_VZ (1UL << 0)
+#define MIPS_HWCAP_EVA (1UL << 1)
+#define MIPS_HWCAP_HTW (1UL << 2)
+#define MIPS_HWCAP_FPU (1UL << 3)
+#define MIPS_HWCAP_MIPS32R2 (1UL << 4)
+#define MIPS_HWCAP_MIPS32R5 (1UL << 5)
+#define MIPS_HWCAP_MIPS64R6 (1UL << 6)
+#define MIPS_HWCAP_DSPR1 (1UL << 7)
+#define MIPS_HWCAP_DSPR2 (1UL << 8)
+#define MIPS_HWCAP_MSA (1UL << 9)
+
+// http://elixir.free-electrons.com/linux/latest/source/arch/powerpc/include/uapi/asm/cputable.h
+#ifndef _UAPI__ASM_POWERPC_CPUTABLE_H
+/* in AT_HWCAP */
+#define PPC_FEATURE_32 0x80000000
+#define PPC_FEATURE_64 0x40000000
+#define PPC_FEATURE_601_INSTR 0x20000000
+#define PPC_FEATURE_HAS_ALTIVEC 0x10000000
+#define PPC_FEATURE_HAS_FPU 0x08000000
+#define PPC_FEATURE_HAS_MMU 0x04000000
+#define PPC_FEATURE_HAS_4xxMAC 0x02000000
+#define PPC_FEATURE_UNIFIED_CACHE 0x01000000
+#define PPC_FEATURE_HAS_SPE 0x00800000
+#define PPC_FEATURE_HAS_EFP_SINGLE 0x00400000
+#define PPC_FEATURE_HAS_EFP_DOUBLE 0x00200000
+#define PPC_FEATURE_NO_TB 0x00100000
+#define PPC_FEATURE_POWER4 0x00080000
+#define PPC_FEATURE_POWER5 0x00040000
+#define PPC_FEATURE_POWER5_PLUS 0x00020000
+#define PPC_FEATURE_CELL 0x00010000
+#define PPC_FEATURE_BOOKE 0x00008000
+#define PPC_FEATURE_SMT 0x00004000
+#define PPC_FEATURE_ICACHE_SNOOP 0x00002000
+#define PPC_FEATURE_ARCH_2_05 0x00001000
+#define PPC_FEATURE_PA6T 0x00000800
+#define PPC_FEATURE_HAS_DFP 0x00000400
+#define PPC_FEATURE_POWER6_EXT 0x00000200
+#define PPC_FEATURE_ARCH_2_06 0x00000100
+#define PPC_FEATURE_HAS_VSX 0x00000080
+
+#define PPC_FEATURE_PSERIES_PERFMON_COMPAT 0x00000040
+
+/* Reserved - do not use                0x00000004 */
+#define PPC_FEATURE_TRUE_LE 0x00000002
+#define PPC_FEATURE_PPC_LE 0x00000001
+
+/* in AT_HWCAP2 */
+#define PPC_FEATURE2_ARCH_2_07 0x80000000
+#define PPC_FEATURE2_HTM 0x40000000
+#define PPC_FEATURE2_DSCR 0x20000000
+#define PPC_FEATURE2_EBB 0x10000000
+#define PPC_FEATURE2_ISEL 0x08000000
+#define PPC_FEATURE2_TAR 0x04000000
+#define PPC_FEATURE2_VEC_CRYPTO 0x02000000
+#define PPC_FEATURE2_HTM_NOSC 0x01000000
+#define PPC_FEATURE2_ARCH_3_00 0x00800000
+#define PPC_FEATURE2_HAS_IEEE128 0x00400000
+#define PPC_FEATURE2_DARN 0x00200000
+#define PPC_FEATURE2_SCV 0x00100000
+#define PPC_FEATURE2_HTM_NO_SUSPEND 0x00080000
+#endif
+
+typedef struct {
+  unsigned long hwcaps;
+  unsigned long hwcaps2;
+} HardwareCapabilities;
+
+HardwareCapabilities CpuFeatures_GetHardwareCapabilities(void);
+
+typedef struct {
+  char platform[64];       // 0 terminated string
+  char base_platform[64];  // 0 terminated string
+} PlatformType;
+
+PlatformType CpuFeatures_GetPlatformType(void);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_HWCAPS_H_
--- a/external/cpu_features/include/internal/linux_features_aggregator.h
+++ b/external/cpu_features/include/internal/linux_features_aggregator.h
@ -0,0 +1,60 @@
+// Copyright 2017 Google Inc.
+//
+// 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.
+
+// CapabilityConfig provides a way to map cpu features to hardware caps and
+// /proc/cpuinfo flags. We then provide functions to update capabilities from
+// either source.
+#ifndef CPU_FEATURES_INCLUDE_INTERNAL_LINUX_FEATURES_AGGREGATOR_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_LINUX_FEATURES_AGGREGATOR_H_
+
+#include <ctype.h>
+#include <stdint.h>
+#include "cpu_features_macros.h"
+#include "internal/hwcaps.h"
+#include "internal/string_view.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+// Use the following macro to declare setter functions to be used in
+// CapabilityConfig.
+#define DECLARE_SETTER(FeatureType, FeatureName)                    \
+  static void set_##FeatureName(void* const features, bool value) { \
+    ((FeatureType*)features)->FeatureName = value;                  \
+  }
+
+// Describes the relationship between hardware caps and /proc/cpuinfo flags.
+typedef struct {
+  const HardwareCapabilities hwcaps_mask;
+  const char* const proc_cpuinfo_flag;
+  void (*set_bit)(void* const, bool);  // setter for the corresponding bit.
+} CapabilityConfig;
+
+// For every config, looks into flags_line for the presence of the
+// corresponding proc_cpuinfo_flag, calls `set_bit` accordingly.
+// Note: features is a pointer to the underlying Feature struct.
+void CpuFeatures_SetFromFlags(const size_t configs_size,
+                              const CapabilityConfig* configs,
+                              const StringView flags_line,
+                              void* const features);
+
+// For every config, looks into hwcaps for the presence of the feature. Calls
+// `set_bit` with true if the hardware capability is found.
+// Note: features is a pointer to the underlying Feature struct.
+void CpuFeatures_OverrideFromHwCaps(const size_t configs_size,
+                                    const CapabilityConfig* configs,
+                                    const HardwareCapabilities hwcaps,
+                                    void* const features);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_LINUX_FEATURES_AGGREGATOR_H_
--- a/external/cpu_features/include/internal/stack_line_reader.h
+++ b/external/cpu_features/include/internal/stack_line_reader.h
@ -0,0 +1,49 @@
+// Copyright 2017 Google Inc.
+//
+// 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.
+
+// Reads a file line by line and stores the data on the stack. This allows
+// parsing files in one go without allocating.
+#ifndef CPU_FEATURES_INCLUDE_INTERNAL_STACK_LINE_READER_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_STACK_LINE_READER_H_
+
+#include <stdbool.h>
+
+#include "cpu_features_macros.h"
+#include "internal/string_view.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+typedef struct {
+  char buffer[STACK_LINE_READER_BUFFER_SIZE];
+  StringView view;
+  int fd;
+  bool skip_mode;
+} StackLineReader;
+
+// Initializes a StackLineReader.
+void StackLineReader_Initialize(StackLineReader* reader, int fd);
+
+typedef struct {
+  StringView line;  // A view of the line.
+  bool eof;         // Nothing more to read, we reached EOF.
+  bool full_line;   // If false the line was truncated to
+                    // STACK_LINE_READER_BUFFER_SIZE.
+} LineResult;
+
+// Reads the file pointed to by fd and tries to read a full line.
+LineResult StackLineReader_NextLine(StackLineReader* reader);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_STACK_LINE_READER_H_
--- a/external/cpu_features/include/internal/string_view.h
+++ b/external/cpu_features/include/internal/string_view.h
@ -0,0 +1,108 @@
+// Copyright 2017 Google Inc.
+//
+// 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.
+
+// A view over a piece of string. The view is not 0 terminated.
+#ifndef CPU_FEATURES_INCLUDE_INTERNAL_STRING_VIEW_H_
+#define CPU_FEATURES_INCLUDE_INTERNAL_STRING_VIEW_H_
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+typedef struct {
+  const char* ptr;
+  size_t size;
+} StringView;
+
+#ifdef __cplusplus
+static const StringView kEmptyStringView = {NULL, 0};
+#else
+static const StringView kEmptyStringView;
+#endif
+
+// Returns a StringView from the provided string.
+// Passing NULL is valid only if size is 0.
+static inline StringView view(const char* str, const size_t size) {
+  StringView view;
+  view.ptr = str;
+  view.size = size;
+  return view;
+}
+
+static inline StringView str(const char* str) { return view(str, strlen(str)); }
+
+// Returns the index of the first occurrence of c in view or -1 if not found.
+int CpuFeatures_StringView_IndexOfChar(const StringView view, char c);
+
+// Returns the index of the first occurrence of sub_view in view or -1 if not
+// found.
+int CpuFeatures_StringView_IndexOf(const StringView view,
+                                   const StringView sub_view);
+
+// Returns whether a is equal to b (same content).
+bool CpuFeatures_StringView_IsEquals(const StringView a, const StringView b);
+
+// Returns whether a starts with b.
+bool CpuFeatures_StringView_StartsWith(const StringView a, const StringView b);
+
+// Removes count characters from the beginning of view or kEmptyStringView if
+// count if greater than view.size.
+StringView CpuFeatures_StringView_PopFront(const StringView str_view,
+                                           size_t count);
+
+// Removes count characters from the end of view or kEmptyStringView if count if
+// greater than view.size.
+StringView CpuFeatures_StringView_PopBack(const StringView str_view,
+                                          size_t count);
+
+// Keeps the count first characters of view or view if count if greater than
+// view.size.
+StringView CpuFeatures_StringView_KeepFront(const StringView str_view,
+                                            size_t count);
+
+// Retrieves the first character of view. If view is empty the behavior is
+// undefined.
+char CpuFeatures_StringView_Front(const StringView view);
+
+// Retrieves the last character of view. If view is empty the behavior is
+// undefined.
+char CpuFeatures_StringView_Back(const StringView view);
+
+// Removes leading and tailing space characters.
+StringView CpuFeatures_StringView_TrimWhitespace(StringView view);
+
+// Convert StringView to positive integer. e.g. "42", "0x2a".
+// Returns -1 on error.
+int CpuFeatures_StringView_ParsePositiveNumber(const StringView view);
+
+// Copies src StringView to dst buffer.
+void CpuFeatures_StringView_CopyString(const StringView src, char* dst,
+                                       size_t dst_size);
+
+// Checks if line contains the specified whitespace separated word.
+bool CpuFeatures_StringView_HasWord(const StringView line,
+                                    const char* const word);
+
+// Get key/value from line. key and value are separated by ": ".
+// key and value are cleaned up from leading and trailing whitespaces.
+bool CpuFeatures_StringView_GetAttributeKeyValue(const StringView line,
+                                                 StringView* key,
+                                                 StringView* value);
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif  // CPU_FEATURES_INCLUDE_INTERNAL_STRING_VIEW_H_
--- a/external/cpu_features/scripts/run_integration.sh
+++ b/external/cpu_features/scripts/run_integration.sh
@ -0,0 +1,173 @@
+#!/bin/bash
+
+readonly SCRIPT_FOLDER=$(cd -P -- "$(dirname -- "$0")" && pwd -P)
+readonly PROJECT_FOLDER="${SCRIPT_FOLDER}/.."
+readonly ARCHIVE_FOLDER=~/cpu_features_archives
+readonly QEMU_INSTALL=${ARCHIVE_FOLDER}/qemu
+readonly DEFAULT_CMAKE_ARGS=" -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=ON"
+
+function extract() {
+  case $1 in
+    *.tar.bz2)   tar xjf "$1"    ;;
+    *.tar.xz)    tar xJf "$1"    ;;
+    *.tar.gz)    tar xzf "$1"    ;;
+    *)
+      echo "don't know how to extract '$1'..."
+      exit 1
+  esac
+}
+
+function unpackifnotexists() {
+  mkdir -p "${ARCHIVE_FOLDER}"
+  cd "${ARCHIVE_FOLDER}" || exit
+  local URL=$1
+  local RELATIVE_FOLDER=$2
+  local DESTINATION="${ARCHIVE_FOLDER}/${RELATIVE_FOLDER}"
+  if [[  ! -d "${DESTINATION}" ]] ; then
+    local ARCHIVE_NAME=$(echo ${URL} | sed 's/.*\///')
+    test -f "${ARCHIVE_NAME}" || wget -q "${URL}"
+    extract "${ARCHIVE_NAME}"
+  fi
+}
+
+function installqemuifneeded() {
+  local VERSION=${QEMU_VERSION:=2.11.1}
+  local ARCHES=${QEMU_ARCHES:=arm aarch64 i386 x86_64 mips mipsel}
+  local TARGETS=${QEMU_TARGETS:=$(echo "$ARCHES" | sed 's#$# #;s#\([^ ]*\) #\1-linux-user #g')}
+
+  if echo "${VERSION} ${TARGETS}" | cmp --silent ${QEMU_INSTALL}/.build -; then
+    echo "qemu ${VERSION} up to date!"
+    return 0
+  fi
+
+  echo "VERSION: ${VERSION}"
+  echo "TARGETS: ${TARGETS}"
+
+  rm -rf ${QEMU_INSTALL}
+
+  # Checking for a tarball before downloading makes testing easier :-)
+  local QEMU_URL="http://wiki.qemu-project.org/download/qemu-${VERSION}.tar.xz"
+  local QEMU_FOLDER="qemu-${VERSION}"
+  unpackifnotexists ${QEMU_URL} ${QEMU_FOLDER}
+  cd ${QEMU_FOLDER} || exit
+
+  ./configure \
+    --prefix="${QEMU_INSTALL}" \
+    --target-list="${TARGETS}" \
+    --disable-docs \
+    --disable-sdl \
+    --disable-gtk \
+    --disable-gnutls \
+    --disable-gcrypt \
+    --disable-nettle \
+    --disable-curses \
+    --static
+
+  make -j4
+  make install
+
+  echo "$VERSION $TARGETS" > ${QEMU_INSTALL}/.build
+}
+
+function assert_defined(){
+  local VALUE=${1}
+  : "${VALUE?"${1} needs to be defined"}"
+}
+
+function integrate() {
+  cd "${PROJECT_FOLDER}" || exit
+  cmake -H. -B"${BUILD_DIR}" ${DEFAULT_CMAKE_ARGS} ${CMAKE_ADDITIONAL_ARGS}
+  cmake --build "${BUILD_DIR}" --target all
+
+  if [[ -n "${QEMU_ARCH}" ]]; then
+    if [[ "${QEMU_ARCH}" == "DISABLED" ]]; then
+      QEMU="true || "
+    else
+      installqemuifneeded
+      QEMU="${QEMU_INSTALL}/bin/qemu-${QEMU_ARCH} ${QEMU_ARGS}"
+    fi
+  else
+    QEMU=""
+  fi
+  # Run tests
+  for test_binary in ${BUILD_DIR}/test/*_test; do ${QEMU} ${test_binary}; done
+  # Run demo program
+  ${QEMU} "${BUILD_DIR}/list_cpu_features"
+}
+
+function expand_linaro_config() {
+  assert_defined TARGET
+  local LINARO_ROOT_URL=https://releases.linaro.org/components/toolchain/binaries/7.2-2017.11
+
+  local GCC_URL=${LINARO_ROOT_URL}/${TARGET}/gcc-linaro-7.2.1-2017.11-x86_64_${TARGET}.tar.xz
+  local GCC_RELATIVE_FOLDER="gcc-linaro-7.2.1-2017.11-x86_64_${TARGET}"
+  unpackifnotexists "${GCC_URL}" "${GCC_RELATIVE_FOLDER}"
+
+  local SYSROOT_URL=${LINARO_ROOT_URL}/${TARGET}/sysroot-glibc-linaro-2.25-2017.11-${TARGET}.tar.xz
+  local SYSROOT_RELATIVE_FOLDER=sysroot-glibc-linaro-2.25-2017.11-${TARGET}
+  unpackifnotexists "${SYSROOT_URL}" "${SYSROOT_RELATIVE_FOLDER}"
+
+  local SYSROOT_FOLDER=${ARCHIVE_FOLDER}/${SYSROOT_RELATIVE_FOLDER}
+  local GCC_FOLDER=${ARCHIVE_FOLDER}/${GCC_RELATIVE_FOLDER}
+
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_SYSROOT=${SYSROOT_FOLDER}"
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_C_COMPILER=${GCC_FOLDER}/bin/${TARGET}-gcc"
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_CXX_COMPILER=${GCC_FOLDER}/bin/${TARGET}-g++"
+
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_FIND_ROOT_PATH_MODE_PROGRAM=NEVER"
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=ONLY"
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_FIND_ROOT_PATH_MODE_PACKAGE=ONLY"
+
+  QEMU_ARGS+=" -L ${SYSROOT_FOLDER}"
+  QEMU_ARGS+=" -E LD_LIBRARY_PATH=/lib"
+}
+
+function expand_codescape_config() {
+  assert_defined TARGET
+  local FLAVOUR=${QEMU_ARCH}-r2-hard
+  local DATE=2016.05-03
+  local CODESCAPE_URL=http://codescape-mips-sdk.imgtec.com/components/toolchain/${DATE}/Codescape.GNU.Tools.Package.${DATE}.for.MIPS.MTI.Linux.CentOS-5.x86_64.tar.gz
+  local GCC_URL=${CODESCAPE_URL}
+  local GCC_RELATIVE_FOLDER=${TARGET}/${DATE}
+  unpackifnotexists "${GCC_URL}" "${GCC_RELATIVE_FOLDER}"
+
+  local SYSROOT_URL=${CODESCAPE_URL}
+  local SYSROOT_FOLDER=${ARCHIVE_FOLDER}/${GCC_RELATIVE_FOLDER}/sysroot/${FLAVOUR}
+  unpackifnotexists "${SYSROOT_URL}" "${SYSROOT_RELATIVE_FOLDER}"
+
+  CMAKE_ADDITIONAL_ARGS+=" -DENABLE_MSA=1"
+  CMAKE_ADDITIONAL_ARGS+=" -DMIPS_CPU=p5600"
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_TOOLCHAIN_FILE=cmake/mips32-linux-gcc.cmake"
+  CMAKE_ADDITIONAL_ARGS+=" -DCROSS=${TARGET}-"
+  CMAKE_ADDITIONAL_ARGS+=" -DCMAKE_FIND_ROOT_PATH=${ARCHIVE_FOLDER}/${GCC_RELATIVE_FOLDER}"
+
+  QEMU_ARGS+=" -L ${SYSROOT_FOLDER}"
+  QEMU_ARGS+=" -E LD_LIBRARY_PATH=/lib"
+  QEMU_ARGS+=" -cpu P5600"
+}
+
+function expand_environment_and_integrate() {
+  assert_defined PROJECT_FOLDER
+  assert_defined TARGET
+
+  BUILD_DIR="${PROJECT_FOLDER}/cmake_build/${TARGET}"
+  mkdir -p "${BUILD_DIR}"
+
+  CMAKE_ADDITIONAL_ARGS=""
+  QEMU_ARGS=""
+
+  case ${TOOLCHAIN} in
+    LINARO)    expand_linaro_config     ;;
+    CODESCAPE) expand_codescape_config  ;;
+    NATIVE)    QEMU_ARCH=""             ;;
+    *)
+              echo "Unknown toolchain '${TOOLCHAIN}'..."
+              exit 1
+  esac
+  integrate
+}
+
+if [ "${CONTINUOUS_INTEGRATION}" = "true" ]; then
+  QEMU_ARCHES=${QEMU_ARCH}
+  expand_environment_and_integrate
+fi
--- a/external/cpu_features/scripts/test_integration.sh
+++ b/external/cpu_features/scripts/test_integration.sh
@ -0,0 +1,80 @@
+source "$(dirname -- "$0")"/run_integration.sh
+
+# Toolchains for little-endian, 64-bit ARMv8 for GNU/Linux systems
+function set_aarch64-linux-gnu() {
+  TOOLCHAIN=LINARO
+  TARGET=aarch64-linux-gnu
+  QEMU_ARCH=aarch64
+}
+
+# Toolchains for little-endian, hard-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems 
+function set_arm-linux-gnueabihf() {
+  TOOLCHAIN=LINARO
+  TARGET=arm-linux-gnueabihf
+  QEMU_ARCH=arm
+}
+
+# Toolchains for little-endian, 32-bit ARMv8 for GNU/Linux systems
+function set_armv8l-linux-gnueabihf() {
+  TOOLCHAIN=LINARO
+  TARGET=armv8l-linux-gnueabihf
+  QEMU_ARCH=arm
+}
+
+# Toolchains for little-endian, soft-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+function set_arm-linux-gnueabi() {
+  TOOLCHAIN=LINARO
+  TARGET=arm-linux-gnueabi
+  QEMU_ARCH=arm
+}
+
+# Toolchains for big-endian, 64-bit ARMv8 for GNU/Linux systems
+function set_aarch64_be-linux-gnu() {
+  TOOLCHAIN=LINARO
+  TARGET=aarch64_be-linux-gnu
+  QEMU_ARCH="DISABLED"
+}
+
+# Toolchains for big-endian, hard-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+function set_armeb-linux-gnueabihf() {
+  TOOLCHAIN=LINARO
+  TARGET=armeb-linux-gnueabihf
+  QEMU_ARCH="DISABLED"
+}
+
+# Toolchains for big-endian, soft-float, 32-bit ARMv7 (and earlier) for GNU/Linux systems
+function set_armeb-linux-gnueabi() {
+  TOOLCHAIN=LINARO
+  TARGET=armeb-linux-gnueabi
+  QEMU_ARCH="DISABLED"
+}
+
+
+function set_mips() {
+  TOOLCHAIN=CODESCAPE
+  TARGET=mips-mti-linux-gnu
+  QEMU_ARCH="DISABLED"
+}
+
+function set_native() {
+  TOOLCHAIN=NATIVE
+  TARGET=native
+  QEMU_ARCH=""
+}
+
+ENVIRONMENTS="
+  set_aarch64-linux-gnu
+  set_arm-linux-gnueabihf
+  set_armv8l-linux-gnueabihf
+  set_arm-linux-gnueabi
+  set_aarch64_be-linux-gnu
+  set_armeb-linux-gnueabihf
+  set_armeb-linux-gnueabi
+  set_native
+  set_mips
+"
+
+for SET_ENVIRONMENT in ${ENVIRONMENTS}; do
+  ${SET_ENVIRONMENT}
+  expand_environment_and_integrate
+done
--- a/external/cpu_features/src/cpuid_x86_clang_gcc.c
+++ b/external/cpu_features/src/cpuid_x86_clang_gcc.c
@ -0,0 +1,36 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/cpuid_x86.h"
+
+#if defined(CPU_FEATURES_ARCH_X86)
+#if defined(CPU_FEATURES_COMPILER_CLANG) || defined(CPU_FEATURES_COMPILER_GCC)
+
+#include <cpuid.h>
+
+Leaf CpuId(uint32_t leaf_id) {
+  Leaf leaf;
+  __cpuid_count(leaf_id, 0, leaf.eax, leaf.ebx, leaf.ecx, leaf.edx);
+  return leaf;
+}
+
+uint32_t GetXCR0Eax(void) {
+  uint32_t eax, edx;
+  __asm("XGETBV" : "=a"(eax), "=d"(edx) : "c"(0));
+  return eax;
+}
+
+#endif  // defined(CPU_FEATURES_COMPILER_CLANG) ||
+        // defined(CPU_FEATURES_COMPILER_GCC)
+#endif  // defined(CPU_FEATURES_ARCH_X86)
--- a/external/cpu_features/src/cpuid_x86_msvc.c
+++ b/external/cpu_features/src/cpuid_x86_msvc.c
@ -0,0 +1,34 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/cpuid_x86.h"
+
+#if defined(CPU_FEATURES_ARCH_X86) && defined(CPU_FEATURES_COMPILER_MSC)
+#include <immintrin.h>
+#include <intrin.h>  // For __cpuidex()
+
+Leaf CpuId(uint32_t leaf_id) {
+  Leaf leaf;
+  int data[4];
+  __cpuid(data, leaf_id);
+  leaf.eax = data[0];
+  leaf.ebx = data[1];
+  leaf.ecx = data[2];
+  leaf.edx = data[3];
+  return leaf;
+}
+
+uint32_t GetXCR0Eax(void) { return _xgetbv(0); }
+
+#endif  // defined(CPU_FEATURES_ARCH_X86) && defined(CPU_FEATURES_COMPILER_MSC)
--- a/external/cpu_features/src/cpuinfo_aarch64.c
+++ b/external/cpu_features/src/cpuinfo_aarch64.c
@ -0,0 +1,141 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_aarch64.h"
+
+#include "internal/filesystem.h"
+#include "internal/hwcaps.h"
+#include "internal/linux_features_aggregator.h"
+#include "internal/stack_line_reader.h"
+#include "internal/string_view.h"
+
+#include <ctype.h>
+
+DECLARE_SETTER(Aarch64Features, fp)
+DECLARE_SETTER(Aarch64Features, asimd)
+DECLARE_SETTER(Aarch64Features, aes)
+DECLARE_SETTER(Aarch64Features, pmull)
+DECLARE_SETTER(Aarch64Features, sha1)
+DECLARE_SETTER(Aarch64Features, sha2)
+DECLARE_SETTER(Aarch64Features, crc32)
+
+static const CapabilityConfig kConfigs[] = {
+    {{AARCH64_HWCAP_FP, 0}, "fp", &set_fp},           //
+    {{AARCH64_HWCAP_ASIMD, 0}, "asimd", &set_asimd},  //
+    {{AARCH64_HWCAP_AES, 0}, "aes", &set_aes},        //
+    {{AARCH64_HWCAP_PMULL, 0}, "pmull", &set_pmull},  //
+    {{AARCH64_HWCAP_SHA1, 0}, "sha1", &set_sha1},     //
+    {{AARCH64_HWCAP_SHA2, 0}, "sha2", &set_sha2},     //
+    {{AARCH64_HWCAP_CRC32, 0}, "crc32", &set_crc32},  //
+};
+
+static const size_t kConfigsSize = sizeof(kConfigs) / sizeof(CapabilityConfig);
+
+static bool HandleAarch64Line(const LineResult result,
+                              Aarch64Info* const info) {
+  StringView line = result.line;
+  StringView key, value;
+  if (CpuFeatures_StringView_GetAttributeKeyValue(line, &key, &value)) {
+    if (CpuFeatures_StringView_IsEquals(key, str("Features"))) {
+      CpuFeatures_SetFromFlags(kConfigsSize, kConfigs, value, &info->features);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU implementer"))) {
+      info->implementer = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU variant"))) {
+      info->variant = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU part"))) {
+      info->part = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU revision"))) {
+      info->revision = CpuFeatures_StringView_ParsePositiveNumber(value);
+    }
+  }
+  return !result.eof;
+}
+
+static void FillProcCpuInfoData(Aarch64Info* const info) {
+  const int fd = CpuFeatures_OpenFile("/proc/cpuinfo");
+  if (fd >= 0) {
+    StackLineReader reader;
+    StackLineReader_Initialize(&reader, fd);
+    for (;;) {
+      if (!HandleAarch64Line(StackLineReader_NextLine(&reader), info)) {
+        break;
+      }
+    }
+    CpuFeatures_CloseFile(fd);
+  }
+}
+
+static const Aarch64Info kEmptyAarch64Info;
+
+Aarch64Info GetAarch64Info(void) {
+  // capabilities are fetched from both getauxval and /proc/cpuinfo so we can
+  // have some information if the executable is sandboxed (aka no access to
+  // /proc/cpuinfo).
+  Aarch64Info info = kEmptyAarch64Info;
+
+  FillProcCpuInfoData(&info);
+  CpuFeatures_OverrideFromHwCaps(kConfigsSize, kConfigs,
+                                 CpuFeatures_GetHardwareCapabilities(),
+                                 &info.features);
+
+  return info;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+int GetAarch64FeaturesEnumValue(const Aarch64Features* features,
+                                Aarch64FeaturesEnum value) {
+  switch (value) {
+    case AARCH64_FP:
+      return features->fp;
+    case AARCH64_ASIMD:
+      return features->asimd;
+    case AARCH64_AES:
+      return features->aes;
+    case AARCH64_PMULL:
+      return features->pmull;
+    case AARCH64_SHA1:
+      return features->sha1;
+    case AARCH64_SHA2:
+      return features->sha2;
+    case AARCH64_CRC32:
+      return features->crc32;
+    case AARCH64_LAST_:
+      break;
+  }
+  return false;
+}
+
+const char* GetAarch64FeaturesEnumName(Aarch64FeaturesEnum value) {
+  switch (value) {
+    case AARCH64_FP:
+      return "fp";
+    case AARCH64_ASIMD:
+      return "asimd";
+    case AARCH64_AES:
+      return "aes";
+    case AARCH64_PMULL:
+      return "pmull";
+    case AARCH64_SHA1:
+      return "sha1";
+    case AARCH64_SHA2:
+      return "sha2";
+    case AARCH64_CRC32:
+      return "crc32";
+    case AARCH64_LAST_:
+      break;
+  }
+  return "unknown feature";
+}
--- a/external/cpu_features/src/cpuinfo_arm.c
+++ b/external/cpu_features/src/cpuinfo_arm.c
@ -0,0 +1,259 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_arm.h"
+
+#include "internal/bit_utils.h"
+#include "internal/filesystem.h"
+#include "internal/hwcaps.h"
+#include "internal/linux_features_aggregator.h"
+#include "internal/stack_line_reader.h"
+#include "internal/string_view.h"
+
+#include <ctype.h>
+
+DECLARE_SETTER(ArmFeatures, vfp)
+DECLARE_SETTER(ArmFeatures, iwmmxt)
+DECLARE_SETTER(ArmFeatures, neon)
+DECLARE_SETTER(ArmFeatures, vfpv3)
+DECLARE_SETTER(ArmFeatures, vfpv3d16)
+DECLARE_SETTER(ArmFeatures, vfpv4)
+DECLARE_SETTER(ArmFeatures, idiva)
+DECLARE_SETTER(ArmFeatures, idivt)
+DECLARE_SETTER(ArmFeatures, aes)
+DECLARE_SETTER(ArmFeatures, pmull)
+DECLARE_SETTER(ArmFeatures, sha1)
+DECLARE_SETTER(ArmFeatures, sha2)
+DECLARE_SETTER(ArmFeatures, crc32)
+
+static const CapabilityConfig kConfigs[] = {
+    {{ARM_HWCAP_VFP, 0}, "vfp", &set_vfp},                 //
+    {{ARM_HWCAP_IWMMXT, 0}, "iwmmxt", &set_iwmmxt},        //
+    {{ARM_HWCAP_NEON, 0}, "neon", &set_neon},              //
+    {{ARM_HWCAP_VFPV3, 0}, "vfpv3", &set_vfpv3},           //
+    {{ARM_HWCAP_VFPV3D16, 0}, "vfpv3d16", &set_vfpv3d16},  //
+    {{ARM_HWCAP_VFPV4, 0}, "vfpv4", &set_vfpv4},           //
+    {{ARM_HWCAP_IDIVA, 0}, "idiva", &set_idiva},           //
+    {{ARM_HWCAP_IDIVT, 0}, "idivt", &set_idivt},           //
+    {{0, ARM_HWCAP2_AES}, "aes", &set_aes},                //
+    {{0, ARM_HWCAP2_PMULL}, "pmull", &set_pmull},          //
+    {{0, ARM_HWCAP2_SHA1}, "sha1", &set_sha1},             //
+    {{0, ARM_HWCAP2_SHA2}, "sha2", &set_sha2},             //
+    {{0, ARM_HWCAP2_CRC32}, "crc32", &set_crc32},          //
+};
+
+static const size_t kConfigsSize = sizeof(kConfigs) / sizeof(CapabilityConfig);
+
+typedef struct {
+  bool processor_reports_armv6;
+  bool hardware_reports_goldfish;
+} ProcCpuInfoData;
+
+static int IndexOfNonDigit(StringView str) {
+  size_t index = 0;
+  while (str.size && isdigit(CpuFeatures_StringView_Front(str))) {
+    str = CpuFeatures_StringView_PopFront(str, 1);
+    ++index;
+  }
+  return index;
+}
+
+static bool HandleArmLine(const LineResult result, ArmInfo* const info,
+                          ProcCpuInfoData* const proc_info) {
+  StringView line = result.line;
+  StringView key, value;
+  if (CpuFeatures_StringView_GetAttributeKeyValue(line, &key, &value)) {
+    if (CpuFeatures_StringView_IsEquals(key, str("Features"))) {
+      CpuFeatures_SetFromFlags(kConfigsSize, kConfigs, value, &info->features);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU implementer"))) {
+      info->implementer = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU variant"))) {
+      info->variant = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU part"))) {
+      info->part = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU revision"))) {
+      info->revision = CpuFeatures_StringView_ParsePositiveNumber(value);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("CPU architecture"))) {
+      // CPU architecture is a number that may be followed by letters. e.g.
+      // "6TEJ", "7".
+      const StringView digits =
+          CpuFeatures_StringView_KeepFront(value, IndexOfNonDigit(value));
+      info->architecture = CpuFeatures_StringView_ParsePositiveNumber(digits);
+    } else if (CpuFeatures_StringView_IsEquals(key, str("Processor"))) {
+      proc_info->processor_reports_armv6 =
+          CpuFeatures_StringView_IndexOf(value, str("(v6l)")) >= 0;
+    } else if (CpuFeatures_StringView_IsEquals(key, str("Hardware"))) {
+      proc_info->hardware_reports_goldfish =
+          CpuFeatures_StringView_IsEquals(value, str("Goldfish"));
+    }
+  }
+  return !result.eof;
+}
+
+static uint32_t GetCpuId(const ArmInfo* const info) {
+  return (ExtractBitRange(info->implementer, 7, 0) << 24) |
+         (ExtractBitRange(info->variant, 3, 0) << 20) |
+         (ExtractBitRange(info->part, 11, 0) << 4) |
+         (ExtractBitRange(info->revision, 3, 0) << 0);
+}
+
+static void FixErrors(ArmInfo* const info,
+                      ProcCpuInfoData* const proc_cpu_info_data) {
+  // Fixing Samsung kernel reporting invalid cpu architecture.
+  // http://code.google.com/p/android/issues/detail?id=10812
+  if (proc_cpu_info_data->processor_reports_armv6 && info->architecture >= 7) {
+    info->architecture = 6;
+  }
+
+  // Handle kernel configuration bugs that prevent the correct reporting of CPU
+  // features.
+  switch (GetCpuId(info)) {
+    case 0x4100C080:
+      // Special case: The emulator-specific Android 4.2 kernel fails to report
+      // support for the 32-bit ARM IDIV instruction. Technically, this is a
+      // feature of the virtual CPU implemented by the emulator. Note that it
+      // could also support Thumb IDIV in the future, and this will have to be
+      // slightly updated.
+      if (info->architecture >= 7 &&
+          proc_cpu_info_data->hardware_reports_goldfish) {
+        info->features.idiva = true;
+      }
+      break;
+    case 0x511004D0:
+      // https://crbug.com/341598.
+      info->features.neon = false;
+      break;
+    case 0x510006F2:
+    case 0x510006F3:
+      // The Nexus 4 (Qualcomm Krait) kernel configuration forgets to report
+      // IDIV support.
+      info->features.idiva = true;
+      info->features.idivt = true;
+      break;
+  }
+
+  // Propagate cpu features.
+  if (info->features.vfpv4) info->features.vfpv3 = true;
+  if (info->features.neon) info->features.vfpv3 = true;
+  if (info->features.vfpv3) info->features.vfp = true;
+}
+
+static void FillProcCpuInfoData(ArmInfo* const info,
+                                ProcCpuInfoData* proc_cpu_info_data) {
+  const int fd = CpuFeatures_OpenFile("/proc/cpuinfo");
+  if (fd >= 0) {
+    StackLineReader reader;
+    StackLineReader_Initialize(&reader, fd);
+    for (;;) {
+      if (!HandleArmLine(StackLineReader_NextLine(&reader), info,
+                         proc_cpu_info_data)) {
+        break;
+      }
+    }
+    CpuFeatures_CloseFile(fd);
+  }
+}
+
+static const ArmInfo kEmptyArmInfo;
+
+static const ProcCpuInfoData kEmptyProcCpuInfoData;
+
+ArmInfo GetArmInfo(void) {
+  // capabilities are fetched from both getauxval and /proc/cpuinfo so we can
+  // have some information if the executable is sandboxed (aka no access to
+  // /proc/cpuinfo).
+  ArmInfo info = kEmptyArmInfo;
+  ProcCpuInfoData proc_cpu_info_data = kEmptyProcCpuInfoData;
+
+  FillProcCpuInfoData(&info, &proc_cpu_info_data);
+  CpuFeatures_OverrideFromHwCaps(kConfigsSize, kConfigs,
+                                 CpuFeatures_GetHardwareCapabilities(),
+                                 &info.features);
+
+  FixErrors(&info, &proc_cpu_info_data);
+
+  return info;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+int GetArmFeaturesEnumValue(const ArmFeatures* features,
+                            ArmFeaturesEnum value) {
+  switch (value) {
+    case ARM_VFP:
+      return features->vfp;
+    case ARM_IWMMXT:
+      return features->iwmmxt;
+    case ARM_NEON:
+      return features->neon;
+    case ARM_VFPV3:
+      return features->vfpv3;
+    case ARM_VFPV3D16:
+      return features->vfpv3d16;
+    case ARM_VFPV4:
+      return features->vfpv4;
+    case ARM_IDIVA:
+      return features->idiva;
+    case ARM_IDIVT:
+      return features->idivt;
+    case ARM_AES:
+      return features->aes;
+    case ARM_PMULL:
+      return features->pmull;
+    case ARM_SHA1:
+      return features->sha1;
+    case ARM_SHA2:
+      return features->sha2;
+    case ARM_CRC32:
+      return features->crc32;
+    case ARM_LAST_:
+      break;
+  }
+  return false;
+}
+
+const char* GetArmFeaturesEnumName(ArmFeaturesEnum value) {
+  switch (value) {
+    case ARM_VFP:
+      return "vfp";
+    case ARM_IWMMXT:
+      return "iwmmxt";
+    case ARM_NEON:
+      return "neon";
+    case ARM_VFPV3:
+      return "vfpv3";
+    case ARM_VFPV3D16:
+      return "vfpv3d16";
+    case ARM_VFPV4:
+      return "vfpv4";
+    case ARM_IDIVA:
+      return "idiva";
+    case ARM_IDIVT:
+      return "idivt";
+    case ARM_AES:
+      return "aes";
+    case ARM_PMULL:
+      return "pmull";
+    case ARM_SHA1:
+      return "sha1";
+    case ARM_SHA2:
+      return "sha2";
+    case ARM_CRC32:
+      return "crc32";
+    case ARM_LAST_:
+      break;
+  }
+  return "unknown feature";
+}
--- a/external/cpu_features/src/cpuinfo_mips.c
+++ b/external/cpu_features/src/cpuinfo_mips.c
@ -0,0 +1,98 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_mips.h"
+
+#include "internal/filesystem.h"
+#include "internal/linux_features_aggregator.h"
+#include "internal/stack_line_reader.h"
+#include "internal/string_view.h"
+
+DECLARE_SETTER(MipsFeatures, msa)
+DECLARE_SETTER(MipsFeatures, eva)
+
+static const CapabilityConfig kConfigs[] = {
+    {{MIPS_HWCAP_MSA, 0}, "msa", &set_msa},  //
+    {{MIPS_HWCAP_EVA, 0}, "eva", &set_eva},  //
+};
+static const size_t kConfigsSize = sizeof(kConfigs) / sizeof(CapabilityConfig);
+
+static bool HandleMipsLine(const LineResult result,
+                           MipsFeatures* const features) {
+  StringView key, value;
+  // See tests for an example.
+  if (CpuFeatures_StringView_GetAttributeKeyValue(result.line, &key, &value)) {
+    if (CpuFeatures_StringView_IsEquals(key, str("ASEs implemented"))) {
+      CpuFeatures_SetFromFlags(kConfigsSize, kConfigs, value, features);
+    }
+  }
+  return !result.eof;
+}
+
+static void FillProcCpuInfoData(MipsFeatures* const features) {
+  const int fd = CpuFeatures_OpenFile("/proc/cpuinfo");
+  if (fd >= 0) {
+    StackLineReader reader;
+    StackLineReader_Initialize(&reader, fd);
+    for (;;) {
+      if (!HandleMipsLine(StackLineReader_NextLine(&reader), features)) {
+        break;
+      }
+    }
+    CpuFeatures_CloseFile(fd);
+  }
+}
+
+static const MipsInfo kEmptyMipsInfo;
+
+MipsInfo GetMipsInfo(void) {
+  // capabilities are fetched from both getauxval and /proc/cpuinfo so we can
+  // have some information if the executable is sandboxed (aka no access to
+  // /proc/cpuinfo).
+  MipsInfo info = kEmptyMipsInfo;
+
+  FillProcCpuInfoData(&info.features);
+  CpuFeatures_OverrideFromHwCaps(kConfigsSize, kConfigs,
+                                 CpuFeatures_GetHardwareCapabilities(),
+                                 &info.features);
+  return info;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+int GetMipsFeaturesEnumValue(const MipsFeatures* features,
+                             MipsFeaturesEnum value) {
+  switch (value) {
+    case MIPS_MSA:
+      return features->msa;
+    case MIPS_EVA:
+      return features->eva;
+    case MIPS_LAST_:
+      break;
+  }
+  return false;
+}
+
+const char* GetMipsFeaturesEnumName(MipsFeaturesEnum value) {
+  switch (value) {
+    case MIPS_MSA:
+      return "msa";
+    case MIPS_EVA:
+      return "eva";
+    case MIPS_LAST_:
+      break;
+  }
+  return "unknown feature";
+}
--- a/external/cpu_features/src/cpuinfo_ppc.c
+++ b/external/cpu_features/src/cpuinfo_ppc.c
@ -0,0 +1,358 @@
+// Copyright 2018 IBM.
+//
+// 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 <stdbool.h>
+#include <string.h>
+
+#include "cpuinfo_ppc.h"
+#include "internal/bit_utils.h"
+#include "internal/filesystem.h"
+#include "internal/linux_features_aggregator.h"
+#include "internal/stack_line_reader.h"
+#include "internal/string_view.h"
+
+DECLARE_SETTER(PPCFeatures, ppc32)
+DECLARE_SETTER(PPCFeatures, ppc64)
+DECLARE_SETTER(PPCFeatures, ppc601)
+DECLARE_SETTER(PPCFeatures, altivec)
+DECLARE_SETTER(PPCFeatures, fpu)
+DECLARE_SETTER(PPCFeatures, mmu)
+DECLARE_SETTER(PPCFeatures, mac_4xx)
+DECLARE_SETTER(PPCFeatures, unifiedcache)
+DECLARE_SETTER(PPCFeatures, spe)
+DECLARE_SETTER(PPCFeatures, efpsingle)
+DECLARE_SETTER(PPCFeatures, efpdouble)
+DECLARE_SETTER(PPCFeatures, no_tb)
+DECLARE_SETTER(PPCFeatures, power4)
+DECLARE_SETTER(PPCFeatures, power5)
+DECLARE_SETTER(PPCFeatures, power5plus)
+DECLARE_SETTER(PPCFeatures, cell)
+DECLARE_SETTER(PPCFeatures, booke)
+DECLARE_SETTER(PPCFeatures, smt)
+DECLARE_SETTER(PPCFeatures, icachesnoop)
+DECLARE_SETTER(PPCFeatures, arch205)
+DECLARE_SETTER(PPCFeatures, pa6t)
+DECLARE_SETTER(PPCFeatures, dfp)
+DECLARE_SETTER(PPCFeatures, power6ext)
+DECLARE_SETTER(PPCFeatures, arch206)
+DECLARE_SETTER(PPCFeatures, vsx)
+DECLARE_SETTER(PPCFeatures, pseries_perfmon_compat)
+DECLARE_SETTER(PPCFeatures, truele)
+DECLARE_SETTER(PPCFeatures, ppcle)
+DECLARE_SETTER(PPCFeatures, arch207)
+DECLARE_SETTER(PPCFeatures, htm)
+DECLARE_SETTER(PPCFeatures, dscr)
+DECLARE_SETTER(PPCFeatures, ebb)
+DECLARE_SETTER(PPCFeatures, isel)
+DECLARE_SETTER(PPCFeatures, tar)
+DECLARE_SETTER(PPCFeatures, vcrypto)
+DECLARE_SETTER(PPCFeatures, htm_nosc)
+DECLARE_SETTER(PPCFeatures, arch300)
+DECLARE_SETTER(PPCFeatures, ieee128)
+DECLARE_SETTER(PPCFeatures, darn)
+DECLARE_SETTER(PPCFeatures, scv)
+DECLARE_SETTER(PPCFeatures, htm_no_suspend)
+
+static const CapabilityConfig kConfigs[] = {
+    {{PPC_FEATURE_32, 0}, "ppc32", &set_ppc32},
+    {{PPC_FEATURE_64, 0}, "ppc64", &set_ppc64},
+    {{PPC_FEATURE_601_INSTR, 0}, "ppc601", &set_ppc601},
+    {{PPC_FEATURE_HAS_ALTIVEC, 0}, "altivec", &set_altivec},
+    {{PPC_FEATURE_HAS_FPU, 0}, "fpu", &set_fpu},
+    {{PPC_FEATURE_HAS_MMU, 0}, "mmu", &set_mmu},
+    {{PPC_FEATURE_HAS_4xxMAC, 0}, "4xxmac", &set_mac_4xx},
+    {{PPC_FEATURE_UNIFIED_CACHE, 0}, "ucache", &set_unifiedcache},
+    {{PPC_FEATURE_HAS_SPE, 0}, "spe", &set_spe},
+    {{PPC_FEATURE_HAS_EFP_SINGLE, 0}, "efpsingle", &set_efpsingle},
+    {{PPC_FEATURE_HAS_EFP_DOUBLE, 0}, "efpdouble", &set_efpdouble},
+    {{PPC_FEATURE_NO_TB, 0}, "notb", &set_no_tb},
+    {{PPC_FEATURE_POWER4, 0}, "power4", &set_power4},
+    {{PPC_FEATURE_POWER5, 0}, "power5", &set_power5},
+    {{PPC_FEATURE_POWER5_PLUS, 0}, "power5+", &set_power5plus},
+    {{PPC_FEATURE_CELL, 0}, "cellbe", &set_cell},
+    {{PPC_FEATURE_BOOKE, 0}, "booke", &set_booke},
+    {{PPC_FEATURE_SMT, 0}, "smt", &set_smt},
+    {{PPC_FEATURE_ICACHE_SNOOP, 0}, "ic_snoop", &set_icachesnoop},
+    {{PPC_FEATURE_ARCH_2_05, 0}, "arch_2_05", &set_arch205},
+    {{PPC_FEATURE_PA6T, 0}, "pa6t", &set_pa6t},
+    {{PPC_FEATURE_HAS_DFP, 0}, "dfp", &set_dfp},
+    {{PPC_FEATURE_POWER6_EXT, 0}, "power6x", &set_power6ext},
+    {{PPC_FEATURE_ARCH_2_06, 0}, "arch_2_06", &set_arch206},
+    {{PPC_FEATURE_HAS_VSX, 0}, "vsx", &set_vsx},
+    {{PPC_FEATURE_PSERIES_PERFMON_COMPAT, 0},
+     "archpmu",
+     &set_pseries_perfmon_compat},
+    {{PPC_FEATURE_TRUE_LE, 0}, "true_le", &set_truele},
+    {{PPC_FEATURE_PPC_LE, 0}, "ppcle", &set_ppcle},
+    {{0, PPC_FEATURE2_ARCH_2_07}, "arch_2_07", &set_arch207},
+    {{0, PPC_FEATURE2_HTM}, "htm", &set_htm},
+    {{0, PPC_FEATURE2_DSCR}, "dscr", &set_dscr},
+    {{0, PPC_FEATURE2_EBB}, "ebb", &set_ebb},
+    {{0, PPC_FEATURE2_ISEL}, "isel", &set_isel},
+    {{0, PPC_FEATURE2_TAR}, "tar", &set_tar},
+    {{0, PPC_FEATURE2_VEC_CRYPTO}, "vcrypto", &set_vcrypto},
+    {{0, PPC_FEATURE2_HTM_NOSC}, "htm-nosc", &set_htm_nosc},
+    {{0, PPC_FEATURE2_ARCH_3_00}, "arch_3_00", &set_arch300},
+    {{0, PPC_FEATURE2_HAS_IEEE128}, "ieee128", &set_ieee128},
+    {{0, PPC_FEATURE2_DARN}, "darn", &set_darn},
+    {{0, PPC_FEATURE2_SCV}, "scv", &set_scv},
+    {{0, PPC_FEATURE2_HTM_NO_SUSPEND}, "htm-no-suspend", &set_htm_no_suspend},
+};
+static const size_t kConfigsSize = sizeof(kConfigs) / sizeof(CapabilityConfig);
+
+static bool HandlePPCLine(const LineResult result,
+                          PPCPlatformStrings* const strings) {
+  StringView line = result.line;
+  StringView key, value;
+  if (CpuFeatures_StringView_GetAttributeKeyValue(line, &key, &value)) {
+    if (CpuFeatures_StringView_HasWord(key, "platform")) {
+      CpuFeatures_StringView_CopyString(value, strings->platform,
+                                        sizeof(strings->platform));
+    } else if (CpuFeatures_StringView_IsEquals(key, str("model"))) {
+      CpuFeatures_StringView_CopyString(value, strings->model,
+                                        sizeof(strings->platform));
+    } else if (CpuFeatures_StringView_IsEquals(key, str("machine"))) {
+      CpuFeatures_StringView_CopyString(value, strings->machine,
+                                        sizeof(strings->platform));
+    } else if (CpuFeatures_StringView_IsEquals(key, str("cpu"))) {
+      CpuFeatures_StringView_CopyString(value, strings->cpu,
+                                        sizeof(strings->platform));
+    }
+  }
+  return !result.eof;
+}
+
+static void FillProcCpuInfoData(PPCPlatformStrings* const strings) {
+  const int fd = CpuFeatures_OpenFile("/proc/cpuinfo");
+  if (fd >= 0) {
+    StackLineReader reader;
+    StackLineReader_Initialize(&reader, fd);
+    for (;;) {
+      if (!HandlePPCLine(StackLineReader_NextLine(&reader), strings)) {
+        break;
+      }
+    }
+    CpuFeatures_CloseFile(fd);
+  }
+}
+
+static const PPCInfo kEmptyPPCInfo;
+
+PPCInfo GetPPCInfo(void) {
+  /*
+   * On Power feature flags aren't currently in cpuinfo so we only look at
+   * the auxilary vector.
+   */
+  PPCInfo info = kEmptyPPCInfo;
+
+  CpuFeatures_OverrideFromHwCaps(kConfigsSize, kConfigs,
+                                 CpuFeatures_GetHardwareCapabilities(),
+                                 &info.features);
+  return info;
+}
+
+static const PPCPlatformStrings kEmptyPPCPlatformStrings;
+
+PPCPlatformStrings GetPPCPlatformStrings(void) {
+  PPCPlatformStrings strings = kEmptyPPCPlatformStrings;
+
+  FillProcCpuInfoData(&strings);
+  strings.type = CpuFeatures_GetPlatformType();
+  return strings;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+int GetPPCFeaturesEnumValue(const PPCFeatures* features,
+                            PPCFeaturesEnum value) {
+  switch (value) {
+    case PPC_32:
+      return features->ppc32;
+    case PPC_64:
+      return features->ppc64;
+    case PPC_601_INSTR:
+      return features->ppc601;
+    case PPC_HAS_ALTIVEC:
+      return features->altivec;
+    case PPC_HAS_FPU:
+      return features->fpu;
+    case PPC_HAS_MMU:
+      return features->mmu;
+    case PPC_HAS_4xxMAC:
+      return features->mac_4xx;
+    case PPC_UNIFIED_CACHE:
+      return features->unifiedcache;
+    case PPC_HAS_SPE:
+      return features->spe;
+    case PPC_HAS_EFP_SINGLE:
+      return features->efpsingle;
+    case PPC_HAS_EFP_DOUBLE:
+      return features->efpdouble;
+    case PPC_NO_TB:
+      return features->no_tb;
+    case PPC_POWER4:
+      return features->power4;
+    case PPC_POWER5:
+      return features->power5;
+    case PPC_POWER5_PLUS:
+      return features->power5plus;
+    case PPC_CELL:
+      return features->cell;
+    case PPC_BOOKE:
+      return features->booke;
+    case PPC_SMT:
+      return features->smt;
+    case PPC_ICACHE_SNOOP:
+      return features->icachesnoop;
+    case PPC_ARCH_2_05:
+      return features->arch205;
+    case PPC_PA6T:
+      return features->pa6t;
+    case PPC_HAS_DFP:
+      return features->dfp;
+    case PPC_POWER6_EXT:
+      return features->power6ext;
+    case PPC_ARCH_2_06:
+      return features->arch206;
+    case PPC_HAS_VSX:
+      return features->vsx;
+    case PPC_PSERIES_PERFMON_COMPAT:
+      return features->pseries_perfmon_compat;
+    case PPC_TRUE_LE:
+      return features->truele;
+    case PPC_PPC_LE:
+      return features->ppcle;
+    case PPC_ARCH_2_07:
+      return features->arch207;
+    case PPC_HTM:
+      return features->htm;
+    case PPC_DSCR:
+      return features->dscr;
+    case PPC_EBB:
+      return features->ebb;
+    case PPC_ISEL:
+      return features->isel;
+    case PPC_TAR:
+      return features->tar;
+    case PPC_VEC_CRYPTO:
+      return features->vcrypto;
+    case PPC_HTM_NOSC:
+      return features->htm_nosc;
+    case PPC_ARCH_3_00:
+      return features->arch300;
+    case PPC_HAS_IEEE128:
+      return features->ieee128;
+    case PPC_DARN:
+      return features->darn;
+    case PPC_SCV:
+      return features->scv;
+    case PPC_HTM_NO_SUSPEND:
+      return features->htm_no_suspend;
+    case PPC_LAST_:
+      break;
+  }
+  return false;
+}
+
+/* Have used the same names as glibc  */
+const char* GetPPCFeaturesEnumName(PPCFeaturesEnum value) {
+  switch (value) {
+    case PPC_32:
+      return "ppc32";
+    case PPC_64:
+      return "ppc64";
+    case PPC_601_INSTR:
+      return "ppc601";
+    case PPC_HAS_ALTIVEC:
+      return "altivec";
+    case PPC_HAS_FPU:
+      return "fpu";
+    case PPC_HAS_MMU:
+      return "mmu";
+    case PPC_HAS_4xxMAC:
+      return "4xxmac";
+    case PPC_UNIFIED_CACHE:
+      return "ucache";
+    case PPC_HAS_SPE:
+      return "spe";
+    case PPC_HAS_EFP_SINGLE:
+      return "efpsingle";
+    case PPC_HAS_EFP_DOUBLE:
+      return "efpdouble";
+    case PPC_NO_TB:
+      return "notb";
+    case PPC_POWER4:
+      return "power4";
+    case PPC_POWER5:
+      return "power5";
+    case PPC_POWER5_PLUS:
+      return "power5+";
+    case PPC_CELL:
+      return "cellbe";
+    case PPC_BOOKE:
+      return "booke";
+    case PPC_SMT:
+      return "smt";
+    case PPC_ICACHE_SNOOP:
+      return "ic_snoop";
+    case PPC_ARCH_2_05:
+      return "arch_2_05";
+    case PPC_PA6T:
+      return "pa6t";
+    case PPC_HAS_DFP:
+      return "dfp";
+    case PPC_POWER6_EXT:
+      return "power6x";
+    case PPC_ARCH_2_06:
+      return "arch_2_06";
+    case PPC_HAS_VSX:
+      return "vsx";
+    case PPC_PSERIES_PERFMON_COMPAT:
+      return "archpmu";
+    case PPC_TRUE_LE:
+      return "true_le";
+    case PPC_PPC_LE:
+      return "ppcle";
+    case PPC_ARCH_2_07:
+      return "arch_2_07";
+    case PPC_HTM:
+      return "htm";
+    case PPC_DSCR:
+      return "dscr";
+    case PPC_EBB:
+      return "ebb";
+    case PPC_ISEL:
+      return "isel";
+    case PPC_TAR:
+      return "tar";
+    case PPC_VEC_CRYPTO:
+      return "vcrypto";
+    case PPC_HTM_NOSC:
+      return "htm-nosc";
+    case PPC_ARCH_3_00:
+      return "arch_3_00";
+    case PPC_HAS_IEEE128:
+      return "ieee128";
+    case PPC_DARN:
+      return "darn";
+    case PPC_SCV:
+      return "scv";
+    case PPC_HTM_NO_SUSPEND:
+      return "htm-no-suspend";
+    case PPC_LAST_:
+      break;
+  }
+  return "unknown_feature";
+}
--- a/external/cpu_features/src/cpuinfo_x86.c
+++ b/external/cpu_features/src/cpuinfo_x86.c
@ -0,0 +1,447 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_x86.h"
+#include "internal/bit_utils.h"
+#include "internal/cpuid_x86.h"
+
+#include <stdbool.h>
+#include <string.h>
+
+static const Leaf kEmptyLeaf;
+
+static Leaf SafeCpuId(uint32_t max_cpuid_leaf, uint32_t leaf_id) {
+  if (leaf_id <= max_cpuid_leaf) {
+    return CpuId(leaf_id);
+  } else {
+    return kEmptyLeaf;
+  }
+}
+
+#define MASK_XMM 0x2
+#define MASK_YMM 0x4
+#define MASK_MASKREG 0x20
+#define MASK_ZMM0_15 0x40
+#define MASK_ZMM16_31 0x80
+
+static bool HasMask(uint32_t value, uint32_t mask) {
+  return (value & mask) == mask;
+}
+
+// Checks that operating system saves and restores xmm registers during context
+// switches.
+static bool HasXmmOsXSave(uint32_t xcr0_eax) {
+  return HasMask(xcr0_eax, MASK_XMM);
+}
+
+// Checks that operating system saves and restores ymm registers during context
+// switches.
+static bool HasYmmOsXSave(uint32_t xcr0_eax) {
+  return HasMask(xcr0_eax, MASK_XMM | MASK_YMM);
+}
+
+// Checks that operating system saves and restores zmm registers during context
+// switches.
+static bool HasZmmOsXSave(uint32_t xcr0_eax) {
+  return HasMask(xcr0_eax, MASK_XMM | MASK_YMM | MASK_MASKREG | MASK_ZMM0_15 |
+                               MASK_ZMM16_31);
+}
+
+static void SetVendor(const Leaf leaf, char* const vendor) {
+  *(uint32_t*)(vendor) = leaf.ebx;
+  *(uint32_t*)(vendor + 4) = leaf.edx;
+  *(uint32_t*)(vendor + 8) = leaf.ecx;
+  vendor[12] = '\0';
+}
+
+static int IsVendor(const Leaf leaf, const char* const name) {
+  const uint32_t ebx = *(const uint32_t*)(name);
+  const uint32_t edx = *(const uint32_t*)(name + 4);
+  const uint32_t ecx = *(const uint32_t*)(name + 8);
+  return leaf.ebx == ebx && leaf.ecx == ecx && leaf.edx == edx;
+}
+
+// Reference https://en.wikipedia.org/wiki/CPUID.
+static void ParseCpuId(const uint32_t max_cpuid_leaf, X86Info* info) {
+  const Leaf leaf_1 = SafeCpuId(max_cpuid_leaf, 1);
+  const Leaf leaf_7 = SafeCpuId(max_cpuid_leaf, 7);
+
+  const bool have_xsave = IsBitSet(leaf_1.ecx, 26);
+  const bool have_osxsave = IsBitSet(leaf_1.ecx, 27);
+  const uint32_t xcr0_eax = (have_xsave && have_osxsave) ? GetXCR0Eax() : 0;
+  const bool have_sse_os_support = HasXmmOsXSave(xcr0_eax);
+  const bool have_avx_os_support = HasYmmOsXSave(xcr0_eax);
+  const bool have_avx512_os_support = HasZmmOsXSave(xcr0_eax);
+
+  const uint32_t family = ExtractBitRange(leaf_1.eax, 11, 8);
+  const uint32_t extended_family = ExtractBitRange(leaf_1.eax, 27, 20);
+  const uint32_t model = ExtractBitRange(leaf_1.eax, 7, 4);
+  const uint32_t extended_model = ExtractBitRange(leaf_1.eax, 19, 16);
+
+  X86Features* const features = &info->features;
+
+  info->family = extended_family + family;
+  info->model = (extended_model << 4) + model;
+  info->stepping = ExtractBitRange(leaf_1.eax, 3, 0);
+
+  features->smx = IsBitSet(leaf_1.ecx, 6);
+  features->cx16 = IsBitSet(leaf_1.ecx, 13);
+  features->aes = IsBitSet(leaf_1.ecx, 25);
+  features->f16c = IsBitSet(leaf_1.ecx, 29);
+  features->sgx = IsBitSet(leaf_7.ebx, 2);
+  features->bmi1 = IsBitSet(leaf_7.ebx, 3);
+  features->bmi2 = IsBitSet(leaf_7.ebx, 8);
+  features->erms = IsBitSet(leaf_7.ebx, 9);
+  features->vpclmulqdq = IsBitSet(leaf_7.ecx, 10);
+
+  if (have_sse_os_support) {
+    features->ssse3 = IsBitSet(leaf_1.ecx, 9);
+    features->sse4_1 = IsBitSet(leaf_1.ecx, 19);
+    features->sse4_2 = IsBitSet(leaf_1.ecx, 20);
+  }
+
+  if (have_avx_os_support) {
+    features->fma3 = IsBitSet(leaf_1.ecx, 12);
+    features->avx = IsBitSet(leaf_1.ecx, 28);
+    features->avx2 = IsBitSet(leaf_7.ebx, 5);
+  }
+
+  if (have_avx512_os_support) {
+    features->avx512f = IsBitSet(leaf_7.ebx, 16);
+    features->avx512cd = IsBitSet(leaf_7.ebx, 28);
+    features->avx512er = IsBitSet(leaf_7.ebx, 27);
+    features->avx512pf = IsBitSet(leaf_7.ebx, 26);
+    features->avx512bw = IsBitSet(leaf_7.ebx, 30);
+    features->avx512dq = IsBitSet(leaf_7.ebx, 17);
+    features->avx512vl = IsBitSet(leaf_7.ebx, 31);
+    features->avx512ifma = IsBitSet(leaf_7.ebx, 21);
+    features->avx512vbmi = IsBitSet(leaf_7.ecx, 1);
+    features->avx512vbmi2 = IsBitSet(leaf_7.ecx, 6);
+    features->avx512vnni = IsBitSet(leaf_7.ecx, 11);
+    features->avx512bitalg = IsBitSet(leaf_7.ecx, 12);
+    features->avx512vpopcntdq = IsBitSet(leaf_7.ecx, 14);
+    features->avx512_4vnniw = IsBitSet(leaf_7.edx, 2);
+    features->avx512_4vbmi2 = IsBitSet(leaf_7.edx, 3);
+  }
+}
+
+static const X86Info kEmptyX86Info;
+
+X86Info GetX86Info(void) {
+  X86Info info = kEmptyX86Info;
+  const Leaf leaf_0 = CpuId(0);
+  const uint32_t max_cpuid_leaf = leaf_0.eax;
+  SetVendor(leaf_0, info.vendor);
+  if (IsVendor(leaf_0, "GenuineIntel") || IsVendor(leaf_0, "AuthenticAMD")) {
+    ParseCpuId(max_cpuid_leaf, &info);
+  }
+  return info;
+}
+
+#define CPUID(FAMILY, MODEL) (((FAMILY & 0xFF) << 8) | (MODEL & 0xFF))
+
+X86Microarchitecture GetX86Microarchitecture(const X86Info* info) {
+  if (memcmp(info->vendor, "GenuineIntel", sizeof(info->vendor)) == 0) {
+    switch (CPUID(info->family, info->model)) {
+      case CPUID(0x06, 0x35):
+      case CPUID(0x06, 0x36):
+        // https://en.wikipedia.org/wiki/Bonnell_(microarchitecture)
+        return INTEL_ATOM_BNL;
+      case CPUID(0x06, 0x37):
+      case CPUID(0x06, 0x4C):
+        // https://en.wikipedia.org/wiki/Silvermont
+        return INTEL_ATOM_SMT;
+      case CPUID(0x06, 0x5C):
+        // https://en.wikipedia.org/wiki/Goldmont
+        return INTEL_ATOM_GMT;
+      case CPUID(0x06, 0x0F):
+      case CPUID(0x06, 0x16):
+        // https://en.wikipedia.org/wiki/Intel_Core_(microarchitecture)
+        return INTEL_CORE;
+      case CPUID(0x06, 0x17):
+      case CPUID(0x06, 0x1D):
+        // https://en.wikipedia.org/wiki/Penryn_(microarchitecture)
+        return INTEL_PNR;
+      case CPUID(0x06, 0x1A):
+      case CPUID(0x06, 0x1E):
+      case CPUID(0x06, 0x1F):
+      case CPUID(0x06, 0x2E):
+        // https://en.wikipedia.org/wiki/Nehalem_(microarchitecture)
+        return INTEL_NHM;
+      case CPUID(0x06, 0x25):
+      case CPUID(0x06, 0x2C):
+      case CPUID(0x06, 0x2F):
+        // https://en.wikipedia.org/wiki/Westmere_(microarchitecture)
+        return INTEL_WSM;
+      case CPUID(0x06, 0x2A):
+      case CPUID(0x06, 0x2D):
+        // https://en.wikipedia.org/wiki/Sandy_Bridge#Models_and_steppings
+        return INTEL_SNB;
+      case CPUID(0x06, 0x3A):
+      case CPUID(0x06, 0x3E):
+        // https://en.wikipedia.org/wiki/Ivy_Bridge_(microarchitecture)#Models_and_steppings
+        return INTEL_IVB;
+      case CPUID(0x06, 0x3C):
+      case CPUID(0x06, 0x3F):
+      case CPUID(0x06, 0x45):
+      case CPUID(0x06, 0x46):
+        // https://en.wikipedia.org/wiki/Haswell_(microarchitecture)
+        return INTEL_HSW;
+      case CPUID(0x06, 0x3D):
+      case CPUID(0x06, 0x47):
+      case CPUID(0x06, 0x4F):
+      case CPUID(0x06, 0x56):
+        // https://en.wikipedia.org/wiki/Broadwell_(microarchitecture)
+        return INTEL_BDW;
+      case CPUID(0x06, 0x4E):
+      case CPUID(0x06, 0x55):
+      case CPUID(0x06, 0x5E):
+        // https://en.wikipedia.org/wiki/Skylake_(microarchitecture)
+        return INTEL_SKL;
+      case CPUID(0x06, 0x8E):
+      case CPUID(0x06, 0x9E):
+        // https://en.wikipedia.org/wiki/Kaby_Lake
+        return INTEL_KBL;
+      default:
+        return X86_UNKNOWN;
+    }
+  }
+  if (memcmp(info->vendor, "AuthenticAMD", sizeof(info->vendor)) == 0) {
+    switch (info->family) {
+        // https://en.wikipedia.org/wiki/List_of_AMD_CPU_microarchitectures
+      case 0x0F:
+        return AMD_HAMMER;
+      case 0x10:
+        return AMD_K10;
+      case 0x14:
+        return AMD_BOBCAT;
+      case 0x15:
+        return AMD_BULLDOZER;
+      case 0x16:
+        return AMD_JAGUAR;
+      case 0x17:
+        return AMD_ZEN;
+      default:
+        return X86_UNKNOWN;
+    }
+  }
+  return X86_UNKNOWN;
+}
+
+static void SetString(const uint32_t max_cpuid_ext_leaf, const uint32_t leaf_id,
+                      char* buffer) {
+  const Leaf leaf = SafeCpuId(max_cpuid_ext_leaf, leaf_id);
+  // We allow calling memcpy from SetString which is only called when requesting
+  // X86BrandString.
+  memcpy(buffer, &leaf, sizeof(Leaf));
+}
+
+void FillX86BrandString(char brand_string[49]) {
+  const Leaf leaf_ext_0 = CpuId(0x80000000);
+  const uint32_t max_cpuid_leaf_ext = leaf_ext_0.eax;
+  SetString(max_cpuid_leaf_ext, 0x80000002, brand_string);
+  SetString(max_cpuid_leaf_ext, 0x80000003, brand_string + 16);
+  SetString(max_cpuid_leaf_ext, 0x80000004, brand_string + 32);
+  brand_string[48] = '\0';
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Introspection functions
+
+int GetX86FeaturesEnumValue(const X86Features* features,
+                            X86FeaturesEnum value) {
+  switch (value) {
+    case X86_AES:
+      return features->aes;
+    case X86_ERMS:
+      return features->erms;
+    case X86_F16C:
+      return features->f16c;
+    case X86_FMA3:
+      return features->fma3;
+    case X86_VPCLMULQDQ:
+      return features->vpclmulqdq;
+    case X86_BMI1:
+      return features->bmi1;
+    case X86_BMI2:
+      return features->bmi2;
+    case X86_SSSE3:
+      return features->ssse3;
+    case X86_SSE4_1:
+      return features->sse4_1;
+    case X86_SSE4_2:
+      return features->sse4_2;
+    case X86_AVX:
+      return features->avx;
+    case X86_AVX2:
+      return features->avx2;
+    case X86_AVX512F:
+      return features->avx512f;
+    case X86_AVX512CD:
+      return features->avx512cd;
+    case X86_AVX512ER:
+      return features->avx512er;
+    case X86_AVX512PF:
+      return features->avx512pf;
+    case X86_AVX512BW:
+      return features->avx512bw;
+    case X86_AVX512DQ:
+      return features->avx512dq;
+    case X86_AVX512VL:
+      return features->avx512vl;
+    case X86_AVX512IFMA:
+      return features->avx512ifma;
+    case X86_AVX512VBMI:
+      return features->avx512vbmi;
+    case X86_AVX512VBMI2:
+      return features->avx512vbmi2;
+    case X86_AVX512VNNI:
+      return features->avx512vnni;
+    case X86_AVX512BITALG:
+      return features->avx512bitalg;
+    case X86_AVX512VPOPCNTDQ:
+      return features->avx512vpopcntdq;
+    case X86_AVX512_4VNNIW:
+      return features->avx512_4vnniw;
+    case X86_AVX512_4VBMI2:
+      return features->avx512_4vbmi2;
+    case X86_SMX:
+      return features->smx;
+    case X86_SGX:
+      return features->sgx;
+    case X86_CX16:
+      return features->cx16;
+    case X86_LAST_:
+      break;
+  }
+  return false;
+}
+
+const char* GetX86FeaturesEnumName(X86FeaturesEnum value) {
+  switch (value) {
+    case X86_AES:
+      return "aes";
+    case X86_ERMS:
+      return "erms";
+    case X86_F16C:
+      return "f16c";
+    case X86_FMA3:
+      return "fma3";
+    case X86_VPCLMULQDQ:
+      return "vpclmulqdq";
+    case X86_BMI1:
+      return "bmi1";
+    case X86_BMI2:
+      return "bmi2";
+    case X86_SSSE3:
+      return "ssse3";
+    case X86_SSE4_1:
+      return "sse4_1";
+    case X86_SSE4_2:
+      return "sse4_2";
+    case X86_AVX:
+      return "avx";
+    case X86_AVX2:
+      return "avx2";
+    case X86_AVX512F:
+      return "avx512f";
+    case X86_AVX512CD:
+      return "avx512cd";
+    case X86_AVX512ER:
+      return "avx512er";
+    case X86_AVX512PF:
+      return "avx512pf";
+    case X86_AVX512BW:
+      return "avx512bw";
+    case X86_AVX512DQ:
+      return "avx512dq";
+    case X86_AVX512VL:
+      return "avx512vl";
+    case X86_AVX512IFMA:
+      return "avx512ifma";
+    case X86_AVX512VBMI:
+      return "avx512vbmi";
+    case X86_AVX512VBMI2:
+      return "avx512vbmi2";
+    case X86_AVX512VNNI:
+      return "avx512vnni";
+    case X86_AVX512BITALG:
+      return "avx512bitalg";
+    case X86_AVX512VPOPCNTDQ:
+      return "avx512vpopcntdq";
+    case X86_AVX512_4VNNIW:
+      return "avx512_4vnniw";
+    case X86_AVX512_4VBMI2:
+      return "avx512_4vbmi2";
+    case X86_SMX:
+      return "smx";
+    case X86_SGX:
+      return "sgx";
+    case X86_CX16:
+      return "cx16";
+    case X86_LAST_:
+      break;
+  }
+  return "unknown_feature";
+}
+
+const char* GetX86MicroarchitectureName(X86Microarchitecture uarch) {
+  switch (uarch) {
+    case X86_UNKNOWN:
+      return "X86_UNKNOWN";
+    case INTEL_CORE:
+      return "INTEL_CORE";
+    case INTEL_PNR:
+      return "INTEL_PNR";
+    case INTEL_NHM:
+      return "INTEL_NHM";
+    case INTEL_ATOM_BNL:
+      return "INTEL_ATOM_BNL";
+    case INTEL_WSM:
+      return "INTEL_WSM";
+    case INTEL_SNB:
+      return "INTEL_SNB";
+    case INTEL_IVB:
+      return "INTEL_IVB";
+    case INTEL_ATOM_SMT:
+      return "INTEL_ATOM_SMT";
+    case INTEL_HSW:
+      return "INTEL_HSW";
+    case INTEL_BDW:
+      return "INTEL_BDW";
+    case INTEL_SKL:
+      return "INTEL_SKL";
+    case INTEL_ATOM_GMT:
+      return "INTEL_ATOM_GMT";
+    case INTEL_KBL:
+      return "INTEL_KBL";
+    case INTEL_CFL:
+      return "INTEL_CFL";
+    case INTEL_CNL:
+      return "INTEL_CNL";
+    case AMD_HAMMER:
+      return "AMD_HAMMER";
+    case AMD_K10:
+      return "AMD_K10";
+    case AMD_BOBCAT:
+      return "AMD_BOBCAT";
+    case AMD_BULLDOZER:
+      return "AMD_BULLDOZER";
+    case AMD_JAGUAR:
+      return "AMD_JAGUAR";
+    case AMD_ZEN:
+      return "AMD_ZEN";
+  }
+  return "unknown microarchitecture";
+}
--- a/external/cpu_features/src/filesystem.c
+++ b/external/cpu_features/src/filesystem.c
@ -0,0 +1,57 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/filesystem.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#if defined(_MSC_VER)
+#include <io.h>
+int CpuFeatures_OpenFile(const char* filename) {
+  return _open(filename, _O_RDONLY);
+}
+
+void CpuFeatures_CloseFile(int file_descriptor) { _close(file_descriptor); }
+
+int CpuFeatures_ReadFile(int file_descriptor, void* buffer,
+                         size_t buffer_size) {
+  return _read(file_descriptor, buffer, buffer_size);
+}
+
+#else
+#include <unistd.h>
+
+int CpuFeatures_OpenFile(const char* filename) {
+  int result;
+  do {
+    result = open(filename, O_RDONLY);
+  } while (result == -1L && errno == EINTR);
+  return result;
+}
+
+void CpuFeatures_CloseFile(int file_descriptor) { close(file_descriptor); }
+
+int CpuFeatures_ReadFile(int file_descriptor, void* buffer,
+                         size_t buffer_size) {
+  int result;
+  do {
+    result = read(file_descriptor, buffer, buffer_size);
+  } while (result == -1L && errno == EINTR);
+  return result;
+}
+
+#endif
--- a/external/cpu_features/src/hwcaps.c
+++ b/external/cpu_features/src/hwcaps.c
@ -0,0 +1,187 @@
+// Copyright 2017 Google Inc.
+//
+// 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 <stdlib.h>
+#include <string.h>
+
+#include "cpu_features_macros.h"
+#include "internal/filesystem.h"
+#include "internal/hwcaps.h"
+#include "internal/string_view.h"
+
+#if defined(NDEBUG)
+#define D(...)
+#else
+#include <stdio.h>
+#define D(...)           \
+  do {                   \
+    printf(__VA_ARGS__); \
+    fflush(stdout);      \
+  } while (0)
+#endif
+
+#if defined(CPU_FEATURES_ARCH_MIPS) || defined(CPU_FEATURES_ARCH_ANY_ARM)
+#define HWCAPS_ANDROID_MIPS_OR_ARM
+#endif
+
+#if defined(CPU_FEATURES_OS_LINUX_OR_ANDROID) && \
+    !defined(HWCAPS_ANDROID_MIPS_OR_ARM)
+#define HWCAPS_REGULAR_LINUX
+#endif
+
+#if defined(HWCAPS_ANDROID_MIPS_OR_ARM) || defined(HWCAPS_REGULAR_LINUX)
+#define HWCAPS_SUPPORTED
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+// Implementation of GetElfHwcapFromGetauxval
+////////////////////////////////////////////////////////////////////////////////
+
+// On Linux we simply use getauxval.
+#if defined(HWCAPS_REGULAR_LINUX)
+#include <dlfcn.h>
+#include <sys/auxv.h>
+static unsigned long GetElfHwcapFromGetauxval(uint32_t hwcap_type) {
+  return getauxval(hwcap_type);
+}
+#endif  // defined(HWCAPS_REGULAR_LINUX)
+
+// On Android we probe the system's C library for a 'getauxval' function and
+// call it if it exits, or return 0 for failure. This function is available
+// since API level 20.
+//
+// This code does *NOT* check for '__ANDROID_API__ >= 20' to support the edge
+// case where some NDK developers use headers for a platform that is newer than
+// the one really targetted by their application. This is typically done to use
+// newer native APIs only when running on more recent Android versions, and
+// requires careful symbol management.
+//
+// Note that getauxval() can't really be re-implemented here, because its
+// implementation does not parse /proc/self/auxv. Instead it depends on values
+// that are passed by the kernel at process-init time to the C runtime
+// initialization layer.
+#if defined(HWCAPS_ANDROID_MIPS_OR_ARM)
+#include <dlfcn.h>
+#define AT_HWCAP 16
+#define AT_HWCAP2 26
+#define AT_PLATFORM 15
+#define AT_BASE_PLATFORM 24
+
+typedef unsigned long getauxval_func_t(unsigned long);
+
+static uint32_t GetElfHwcapFromGetauxval(uint32_t hwcap_type) {
+  uint32_t ret = 0;
+  void* libc_handle = NULL;
+  getauxval_func_t* func = NULL;
+
+  dlerror();  // Cleaning error state before calling dlopen.
+  libc_handle = dlopen("libc.so", RTLD_NOW);
+  if (!libc_handle) {
+    D("Could not dlopen() C library: %s\n", dlerror());
+    return 0;
+  }
+  func = (getauxval_func_t*)dlsym(libc_handle, "getauxval");
+  if (!func) {
+    D("Could not find getauxval() in C library\n");
+  } else {
+    // Note: getauxval() returns 0 on failure. Doesn't touch errno.
+    ret = (uint32_t)(*func)(hwcap_type);
+  }
+  dlclose(libc_handle);
+  return ret;
+}
+#endif  // defined(HWCAPS_ANDROID_MIPS_OR_ARM)
+
+#if defined(HWCAPS_SUPPORTED)
+////////////////////////////////////////////////////////////////////////////////
+// Implementation of GetHardwareCapabilities for Android and Linux
+////////////////////////////////////////////////////////////////////////////////
+
+// Fallback when getauxval is not available, retrieves hwcaps from
+// "/proc/self/auxv".
+static uint32_t GetElfHwcapFromProcSelfAuxv(uint32_t hwcap_type) {
+  struct {
+    uint32_t tag;
+    uint32_t value;
+  } entry;
+  uint32_t result = 0;
+  const char filepath[] = "/proc/self/auxv";
+  const int fd = CpuFeatures_OpenFile(filepath);
+  if (fd < 0) {
+    D("Could not open %s\n", filepath);
+    return 0;
+  }
+  for (;;) {
+    const int ret = CpuFeatures_ReadFile(fd, (char*)&entry, sizeof entry);
+    if (ret < 0) {
+      D("Error while reading %s\n", filepath);
+      break;
+    }
+    // Detect end of list.
+    if (ret == 0 || (entry.tag == 0 && entry.value == 0)) {
+      break;
+    }
+    if (entry.tag == hwcap_type) {
+      result = entry.value;
+      break;
+    }
+  }
+  CpuFeatures_CloseFile(fd);
+  return result;
+}
+
+// Retrieves hardware capabilities by first trying to call getauxval, if not
+// available falls back to reading "/proc/self/auxv".
+static unsigned long GetHardwareCapabilitiesFor(uint32_t type) {
+  unsigned long hwcaps = GetElfHwcapFromGetauxval(type);
+  if (!hwcaps) {
+    D("Parsing /proc/self/auxv to extract ELF hwcaps!\n");
+    hwcaps = GetElfHwcapFromProcSelfAuxv(type);
+  }
+  return hwcaps;
+}
+
+HardwareCapabilities CpuFeatures_GetHardwareCapabilities(void) {
+  HardwareCapabilities capabilities;
+  capabilities.hwcaps = GetHardwareCapabilitiesFor(AT_HWCAP);
+  capabilities.hwcaps2 = GetHardwareCapabilitiesFor(AT_HWCAP2);
+  return capabilities;
+}
+
+PlatformType kEmptyPlatformType;
+
+PlatformType CpuFeatures_GetPlatformType(void) {
+  PlatformType type = kEmptyPlatformType;
+  char *platform = (char *)GetHardwareCapabilitiesFor(AT_PLATFORM);
+  char *base_platform = (char *)GetHardwareCapabilitiesFor(AT_BASE_PLATFORM);
+
+  if (platform != NULL)
+    CpuFeatures_StringView_CopyString(str(platform), type.platform,
+                                      sizeof(type.platform));
+  if (base_platform != NULL)
+    CpuFeatures_StringView_CopyString(str(base_platform), type.base_platform,
+                                      sizeof(type.base_platform));
+  return type;
+}
+#else  // (defined(HWCAPS_SUPPORTED)
+
+////////////////////////////////////////////////////////////////////////////////
+// Implementation of GetHardwareCapabilities for unsupported platforms.
+////////////////////////////////////////////////////////////////////////////////
+
+const HardwareCapabilities kEmptyHardwareCapabilities;
+HardwareCapabilities CpuFeatures_GetHardwareCapabilities(void) {
+  return kEmptyHardwareCapabilities;
+}
+#endif
--- a/external/cpu_features/src/linux_features_aggregator.c
+++ b/external/cpu_features/src/linux_features_aggregator.c
@ -0,0 +1,51 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/linux_features_aggregator.h"
+#include "internal/string_view.h"
+
+void CpuFeatures_SetFromFlags(const size_t configs_size,
+                              const CapabilityConfig* configs,
+                              const StringView flags_line,
+                              void* const features) {
+  size_t i = 0;
+  for (; i < configs_size; ++i) {
+    const CapabilityConfig config = configs[i];
+    config.set_bit(features, CpuFeatures_StringView_HasWord(
+                                 flags_line, config.proc_cpuinfo_flag));
+  }
+}
+
+static bool IsSet(const uint32_t mask, const uint32_t value) {
+  return (value & mask) == mask;
+}
+
+static bool IsHwCapsSet(const HardwareCapabilities hwcaps_mask,
+                        const HardwareCapabilities hwcaps) {
+  return IsSet(hwcaps_mask.hwcaps, hwcaps.hwcaps) &&
+         IsSet(hwcaps_mask.hwcaps2, hwcaps.hwcaps2);
+}
+
+void CpuFeatures_OverrideFromHwCaps(const size_t configs_size,
+                                    const CapabilityConfig* configs,
+                                    const HardwareCapabilities hwcaps,
+                                    void* const features) {
+  size_t i = 0;
+  for (; i < configs_size; ++i) {
+    const CapabilityConfig* config = &configs[i];
+    if (IsHwCapsSet(config->hwcaps_mask, hwcaps)) {
+      config->set_bit(features, true);
+    }
+  }
+}
--- a/external/cpu_features/src/stack_line_reader.c
+++ b/external/cpu_features/src/stack_line_reader.c
@ -0,0 +1,131 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/stack_line_reader.h"
+#include "internal/filesystem.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+
+void StackLineReader_Initialize(StackLineReader* reader, int fd) {
+  reader->view.ptr = reader->buffer;
+  reader->view.size = 0;
+  reader->skip_mode = false;
+  reader->fd = fd;
+}
+
+// Replaces the content of buffer with bytes from the file.
+static int LoadFullBuffer(StackLineReader* reader) {
+  const int read = CpuFeatures_ReadFile(reader->fd, reader->buffer,
+                                        STACK_LINE_READER_BUFFER_SIZE);
+  assert(read >= 0);
+  reader->view.ptr = reader->buffer;
+  reader->view.size = read;
+  return read;
+}
+
+// Appends with bytes from the file to buffer, filling the remaining space.
+static int LoadMore(StackLineReader* reader) {
+  char* const ptr = reader->buffer + reader->view.size;
+  const size_t size_to_read = STACK_LINE_READER_BUFFER_SIZE - reader->view.size;
+  const int read = CpuFeatures_ReadFile(reader->fd, ptr, size_to_read);
+  assert(read >= 0);
+  assert(read <= (int)size_to_read);
+  reader->view.size += read;
+  return read;
+}
+
+static int IndexOfEol(StackLineReader* reader) {
+  return CpuFeatures_StringView_IndexOfChar(reader->view, '\n');
+}
+
+// Relocate buffer's pending bytes at the beginning of the array and fills the
+// remaining space with bytes from the file.
+static int BringToFrontAndLoadMore(StackLineReader* reader) {
+  if (reader->view.size && reader->view.ptr != reader->buffer) {
+    memmove(reader->buffer, reader->view.ptr, reader->view.size);
+  }
+  reader->view.ptr = reader->buffer;
+  return LoadMore(reader);
+}
+
+// Loads chunks of buffer size from disks until it contains a newline character
+// or end of file.
+static void SkipToNextLine(StackLineReader* reader) {
+  for (;;) {
+    const int read = LoadFullBuffer(reader);
+    if (read == 0) {
+      break;
+    } else {
+      const int eol_index = IndexOfEol(reader);
+      if (eol_index >= 0) {
+        reader->view =
+            CpuFeatures_StringView_PopFront(reader->view, eol_index + 1);
+        break;
+      }
+    }
+  }
+}
+
+static LineResult CreateLineResult(bool eof, bool full_line, StringView view) {
+  LineResult result;
+  result.eof = eof;
+  result.full_line = full_line;
+  result.line = view;
+  return result;
+}
+
+// Helper methods to provide clearer semantic in StackLineReader_NextLine.
+static LineResult CreateEOFLineResult(StringView view) {
+  return CreateLineResult(true, true, view);
+}
+
+static LineResult CreateTruncatedLineResult(StringView view) {
+  return CreateLineResult(false, false, view);
+}
+
+static LineResult CreateValidLineResult(StringView view) {
+  return CreateLineResult(false, true, view);
+}
+
+LineResult StackLineReader_NextLine(StackLineReader* reader) {
+  if (reader->skip_mode) {
+    SkipToNextLine(reader);
+    reader->skip_mode = false;
+  }
+  {
+    const bool can_load_more =
+        reader->view.size < STACK_LINE_READER_BUFFER_SIZE;
+    int eol_index = IndexOfEol(reader);
+    if (eol_index < 0 && can_load_more) {
+      const int read = BringToFrontAndLoadMore(reader);
+      if (read == 0) {
+        return CreateEOFLineResult(reader->view);
+      }
+      eol_index = IndexOfEol(reader);
+    }
+    if (eol_index < 0) {
+      reader->skip_mode = true;
+      return CreateTruncatedLineResult(reader->view);
+    }
+    {
+      StringView line =
+          CpuFeatures_StringView_KeepFront(reader->view, eol_index);
+      reader->view =
+          CpuFeatures_StringView_PopFront(reader->view, eol_index + 1);
+      return CreateValidLineResult(line);
+    }
+  }
+}
--- a/external/cpu_features/src/string_view.c
+++ b/external/cpu_features/src/string_view.c
@ -0,0 +1,182 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/string_view.h"
+
+#include <assert.h>
+#include <ctype.h>
+#include <string.h>
+
+int CpuFeatures_StringView_IndexOfChar(const StringView view, char c) {
+  if (view.ptr && view.size) {
+    const char* const found = (const char*)memchr(view.ptr, c, view.size);
+    if (found) {
+      return found - view.ptr;
+    }
+  }
+  return -1;
+}
+
+int CpuFeatures_StringView_IndexOf(const StringView view,
+                                   const StringView sub_view) {
+  if (sub_view.size) {
+    StringView remainder = view;
+    while (remainder.size >= sub_view.size) {
+      const int found_index =
+          CpuFeatures_StringView_IndexOfChar(remainder, sub_view.ptr[0]);
+      if (found_index < 0) break;
+      remainder = CpuFeatures_StringView_PopFront(remainder, found_index);
+      if (CpuFeatures_StringView_StartsWith(remainder, sub_view)) {
+        return remainder.ptr - view.ptr;
+      }
+      remainder = CpuFeatures_StringView_PopFront(remainder, 1);
+    }
+  }
+  return -1;
+}
+
+bool CpuFeatures_StringView_IsEquals(const StringView a, const StringView b) {
+  if (a.size == b.size) {
+    return a.ptr == b.ptr || memcmp(a.ptr, b.ptr, b.size) == 0;
+  }
+  return false;
+}
+
+bool CpuFeatures_StringView_StartsWith(const StringView a, const StringView b) {
+  return a.ptr && b.ptr && b.size && a.size >= b.size
+             ? memcmp(a.ptr, b.ptr, b.size) == 0
+             : false;
+}
+
+StringView CpuFeatures_StringView_PopFront(const StringView str_view,
+                                           size_t count) {
+  if (count > str_view.size) {
+    return kEmptyStringView;
+  }
+  return view(str_view.ptr + count, str_view.size - count);
+}
+
+StringView CpuFeatures_StringView_PopBack(const StringView str_view,
+                                          size_t count) {
+  if (count > str_view.size) {
+    return kEmptyStringView;
+  }
+  return view(str_view.ptr, str_view.size - count);
+}
+
+StringView CpuFeatures_StringView_KeepFront(const StringView str_view,
+                                            size_t count) {
+  return count <= str_view.size ? view(str_view.ptr, count) : str_view;
+}
+
+char CpuFeatures_StringView_Front(const StringView view) {
+  assert(view.size);
+  assert(view.ptr);
+  return view.ptr[0];
+}
+
+char CpuFeatures_StringView_Back(const StringView view) {
+  assert(view.size);
+  return view.ptr[view.size - 1];
+}
+
+StringView CpuFeatures_StringView_TrimWhitespace(StringView view) {
+  while (view.size && isspace(CpuFeatures_StringView_Front(view)))
+    view = CpuFeatures_StringView_PopFront(view, 1);
+  while (view.size && isspace(CpuFeatures_StringView_Back(view)))
+    view = CpuFeatures_StringView_PopBack(view, 1);
+  return view;
+}
+
+static int HexValue(const char c) {
+  if (c >= '0' && c <= '9') return c - '0';
+  if (c >= 'a' && c <= 'f') return c - 'a' + 10;
+  if (c >= 'A' && c <= 'F') return c - 'A' + 10;
+  return -1;
+}
+
+// Returns -1 if view contains non digits.
+static int ParsePositiveNumberWithBase(const StringView view, int base) {
+  int result = 0;
+  StringView remainder = view;
+  for (; remainder.size;
+       remainder = CpuFeatures_StringView_PopFront(remainder, 1)) {
+    const int value = HexValue(CpuFeatures_StringView_Front(remainder));
+    if (value < 0 || value >= base) return -1;
+    result = (result * base) + value;
+  }
+  return result;
+}
+
+int CpuFeatures_StringView_ParsePositiveNumber(const StringView view) {
+  if (view.size) {
+    const StringView hex_prefix = str("0x");
+    if (CpuFeatures_StringView_StartsWith(view, hex_prefix)) {
+      const StringView span_no_prefix =
+          CpuFeatures_StringView_PopFront(view, hex_prefix.size);
+      return ParsePositiveNumberWithBase(span_no_prefix, 16);
+    }
+    return ParsePositiveNumberWithBase(view, 10);
+  }
+  return -1;
+}
+
+void CpuFeatures_StringView_CopyString(const StringView src, char* dst,
+                                       size_t dst_size) {
+  if (dst_size > 0) {
+    const size_t max_copy_size = dst_size - 1;
+    const size_t copy_size =
+        src.size > max_copy_size ? max_copy_size : src.size;
+    memcpy(dst, src.ptr, copy_size);
+    dst[copy_size] = '\0';
+  }
+}
+
+bool CpuFeatures_StringView_HasWord(const StringView line,
+                                    const char* const word_str) {
+  const StringView word = str(word_str);
+  StringView remainder = line;
+  for (;;) {
+    const int index_of_word = CpuFeatures_StringView_IndexOf(remainder, word);
+    if (index_of_word < 0) {
+      return false;
+    } else {
+      const StringView before =
+          CpuFeatures_StringView_KeepFront(line, index_of_word);
+      const StringView after =
+          CpuFeatures_StringView_PopFront(line, index_of_word + word.size);
+      const bool valid_before =
+          before.size == 0 || CpuFeatures_StringView_Back(before) == ' ';
+      const bool valid_after =
+          after.size == 0 || CpuFeatures_StringView_Front(after) == ' ';
+      if (valid_before && valid_after) return true;
+      remainder =
+          CpuFeatures_StringView_PopFront(remainder, index_of_word + word.size);
+    }
+  }
+  return false;
+}
+
+bool CpuFeatures_StringView_GetAttributeKeyValue(const StringView line,
+                                                 StringView* key,
+                                                 StringView* value) {
+  const StringView sep = str(": ");
+  const int index_of_separator = CpuFeatures_StringView_IndexOf(line, sep);
+  if (index_of_separator < 0) return false;
+  *value = CpuFeatures_StringView_TrimWhitespace(
+      CpuFeatures_StringView_PopFront(line, index_of_separator + sep.size));
+  *key = CpuFeatures_StringView_TrimWhitespace(
+      CpuFeatures_StringView_KeepFront(line, index_of_separator));
+  return true;
+}
--- a/external/cpu_features/src/utils/list_cpu_features.c
+++ b/external/cpu_features/src/utils/list_cpu_features.c
@ -0,0 +1,237 @@
+// Copyright 2017 Google Inc.
+//
+// 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "cpu_features_macros.h"
+#include "cpuinfo_aarch64.h"
+#include "cpuinfo_arm.h"
+#include "cpuinfo_mips.h"
+#include "cpuinfo_ppc.h"
+#include "cpuinfo_x86.h"
+
+static void PrintEscapedAscii(const char* str) {
+  putchar('"');
+  for (; str && *str; ++str) {
+    switch (*str) {
+      case '\"':
+      case '\\':
+      case '/':
+      case '\b':
+      case '\f':
+      case '\n':
+      case '\r':
+      case '\t':
+        putchar('\\');
+    }
+    putchar(*str);
+  }
+  putchar('"');
+}
+
+static void PrintVoid(void) {}
+static void PrintComma(void) { putchar(','); }
+static void PrintLineFeed(void) { putchar('\n'); }
+static void PrintOpenBrace(void) { putchar('{'); }
+static void PrintCloseBrace(void) { putchar('}'); }
+static void PrintOpenBracket(void) { putchar('['); }
+static void PrintCloseBracket(void) { putchar(']'); }
+static void PrintString(const char* field) { printf("%s", field); }
+static void PrintAlignedHeader(const char* field) { printf("%-15s : ", field); }
+static void PrintIntValue(int value) { printf("%d", value); }
+static void PrintDecHexValue(int value) {
+  printf("%3d (0x%02X)", value, value);
+}
+static void PrintJsonHeader(const char* field) {
+  PrintEscapedAscii(field);
+  putchar(':');
+}
+
+typedef struct {
+  void (*Start)(void);
+  void (*ArrayStart)(void);
+  void (*ArraySeparator)(void);
+  void (*ArrayEnd)(void);
+  void (*PrintString)(const char* value);
+  void (*PrintValue)(int value);
+  void (*EndField)(void);
+  void (*StartField)(const char* field);
+  void (*End)(void);
+} Printer;
+
+static Printer getJsonPrinter(void) {
+  return (Printer){
+      .Start = &PrintOpenBrace,
+      .ArrayStart = &PrintOpenBracket,
+      .ArraySeparator = &PrintComma,
+      .ArrayEnd = &PrintCloseBracket,
+      .PrintString = &PrintEscapedAscii,
+      .PrintValue = &PrintIntValue,
+      .EndField = &PrintComma,
+      .StartField = &PrintJsonHeader,
+      .End = &PrintCloseBrace,
+  };
+}
+
+static Printer getTextPrinter(void) {
+  return (Printer){
+      .Start = &PrintVoid,
+      .ArrayStart = &PrintVoid,
+      .ArraySeparator = &PrintComma,
+      .ArrayEnd = &PrintVoid,
+      .PrintString = &PrintString,
+      .PrintValue = &PrintDecHexValue,
+      .EndField = &PrintLineFeed,
+      .StartField = &PrintAlignedHeader,
+      .End = &PrintVoid,
+  };
+}
+
+// Prints a named numeric value in both decimal and hexadecimal.
+static void PrintN(const Printer p, const char* field, int value) {
+  p.StartField(field);
+  p.PrintValue(value);
+  p.EndField();
+}
+
+// Prints a named string.
+static void PrintS(const Printer p, const char* field, const char* value) {
+  p.StartField(field);
+  p.PrintString(value);
+  p.EndField();
+}
+
+static int cmp(const void* p1, const void* p2) {
+  return strcmp(*(const char* const*)p1, *(const char* const*)p2);
+}
+
+#define DEFINE_PRINT_FLAGS(HasFeature, FeatureName, FeatureType, LastEnum) \
+  static void PrintFlags(const Printer p, const FeatureType* features) {   \
+    size_t i;                                                              \
+    const char* ptrs[LastEnum] = {0};                                      \
+    size_t count = 0;                                                      \
+    for (i = 0; i < LastEnum; ++i) {                                       \
+      if (HasFeature(features, i)) {                                       \
+        ptrs[count] = FeatureName(i);                                      \
+        ++count;                                                           \
+      }                                                                    \
+    }                                                                      \
+    qsort(ptrs, count, sizeof(char*), cmp);                                \
+    p.StartField("flags");                                                 \
+    p.ArrayStart();                                                        \
+    for (i = 0; i < count; ++i) {                                          \
+      if (i > 0) p.ArraySeparator();                                       \
+      p.PrintString(ptrs[i]);                                              \
+    }                                                                      \
+    p.ArrayEnd();                                                          \
+  }
+
+#if defined(CPU_FEATURES_ARCH_X86)
+DEFINE_PRINT_FLAGS(GetX86FeaturesEnumValue, GetX86FeaturesEnumName, X86Features,
+                   X86_LAST_)
+#elif defined(CPU_FEATURES_ARCH_ARM)
+DEFINE_PRINT_FLAGS(GetArmFeaturesEnumValue, GetArmFeaturesEnumName, ArmFeatures,
+                   ARM_LAST_)
+#elif defined(CPU_FEATURES_ARCH_AARCH64)
+DEFINE_PRINT_FLAGS(GetAarch64FeaturesEnumValue, GetAarch64FeaturesEnumName,
+                   Aarch64Features, AARCH64_LAST_)
+#elif defined(CPU_FEATURES_ARCH_MIPS)
+DEFINE_PRINT_FLAGS(GetMipsFeaturesEnumValue, GetMipsFeaturesEnumName,
+                   MipsFeatures, MIPS_LAST_)
+#elif defined(CPU_FEATURES_ARCH_PPC)
+DEFINE_PRINT_FLAGS(GetPPCFeaturesEnumValue, GetPPCFeaturesEnumName, PPCFeatures,
+                   PPC_LAST_)
+#endif
+
+static void PrintFeatures(const Printer printer) {
+#if defined(CPU_FEATURES_ARCH_X86)
+  char brand_string[49];
+  const X86Info info = GetX86Info();
+  FillX86BrandString(brand_string);
+  PrintS(printer, "arch", "x86");
+  PrintS(printer, "brand", brand_string);
+  PrintN(printer, "family", info.family);
+  PrintN(printer, "model", info.model);
+  PrintN(printer, "stepping", info.stepping);
+  PrintS(printer, "uarch",
+         GetX86MicroarchitectureName(GetX86Microarchitecture(&info)));
+  PrintFlags(printer, &info.features);
+#elif defined(CPU_FEATURES_ARCH_ARM)
+  const ArmInfo info = GetArmInfo();
+  PrintS(printer, "arch", "ARM");
+  PrintN(printer, "implementer", info.implementer);
+  PrintN(printer, "architecture", info.architecture);
+  PrintN(printer, "variant", info.variant);
+  PrintN(printer, "part", info.part);
+  PrintN(printer, "revision", info.revision);
+  PrintFlags(printer, &info.features);
+#elif defined(CPU_FEATURES_ARCH_AARCH64)
+  const Aarch64Info info = GetAarch64Info();
+  PrintS(printer, "arch", "aarch64");
+  PrintN(printer, "implementer", info.implementer);
+  PrintN(printer, "variant", info.variant);
+  PrintN(printer, "part", info.part);
+  PrintN(printer, "revision", info.revision);
+  PrintFlags(printer, &info.features);
+#elif defined(CPU_FEATURES_ARCH_MIPS)
+  const MipsInfo info = GetMipsInfo();
+  PrintS(printer, "arch", "mips");
+  PrintFlags(printer, &info.features);
+#elif defined(CPU_FEATURES_ARCH_PPC)
+  const PPCInfo info = GetPPCInfo();
+  const PPCPlatformStrings strings = GetPPCPlatformStrings();
+  PrintS(printer, "arch", "ppc");
+  PrintS(printer, "platform", strings.platform);
+  PrintS(printer, "model", strings.model);
+  PrintS(printer, "machine", strings.machine);
+  PrintS(printer, "cpu", strings.cpu);
+  PrintS(printer, "instruction set", strings.type.platform);
+  PrintS(printer, "microarchitecture", strings.type.base_platform);
+  PrintFlags(printer, &info.features);
+#endif
+}
+
+static void showUsage(const char* name) {
+  printf(
+      "\n"
+      "Usage: %s [options]\n"
+      "      Options:\n"
+      "      -h | --help     Show help message.\n"
+      "      -j | --json     Format output as json instead of plain text.\n"
+      "\n",
+      name);
+}
+
+int main(int argc, char** argv) {
+  Printer printer = getTextPrinter();
+  int i = 1;
+  for (; i < argc; ++i) {
+    const char* arg = argv[i];
+    if (strcmp(arg, "-j") == 0 || strcmp(arg, "--json") == 0) {
+      printer = getJsonPrinter();
+    } else {
+      showUsage(argv[0]);
+      if (strcmp(arg, "-h") == 0 || strcmp(arg, "--help") == 0)
+        return EXIT_SUCCESS;
+      return EXIT_FAILURE;
+    }
+  }
+  printer.Start();
+  PrintFeatures(printer);
+  printer.End();
+  PrintLineFeed();
+  return EXIT_SUCCESS;
+}
--- a/external/cpu_features/test/CMakeLists.txt
+++ b/external/cpu_features/test/CMakeLists.txt
@ -0,0 +1,79 @@
+#
+# libraries for tests
+#
+
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF) # prefer use of -std11 instead of -gnustd11
+
+include_directories(../include)
+add_definitions(-DCPU_FEATURES_TEST)
+
+##------------------------------------------------------------------------------
+add_library(string_view ../src/string_view.c)
+##------------------------------------------------------------------------------
+add_library(filesystem_for_testing filesystem_for_testing.cc)
+##------------------------------------------------------------------------------
+add_library(hwcaps_for_testing hwcaps_for_testing.cc)
+target_link_libraries(hwcaps_for_testing filesystem_for_testing)
+##------------------------------------------------------------------------------
+add_library(stack_line_reader ../src/stack_line_reader.c)
+target_compile_definitions(stack_line_reader PUBLIC STACK_LINE_READER_BUFFER_SIZE=1024)
+target_link_libraries(stack_line_reader string_view)
+##------------------------------------------------------------------------------
+add_library(stack_line_reader_for_test ../src/stack_line_reader.c)
+target_compile_definitions(stack_line_reader_for_test PUBLIC STACK_LINE_READER_BUFFER_SIZE=16)
+target_link_libraries(stack_line_reader_for_test string_view filesystem_for_testing)
+##------------------------------------------------------------------------------
+add_library(all_libraries ../src/stack_line_reader.c ../src/linux_features_aggregator.c)
+target_link_libraries(all_libraries hwcaps_for_testing stack_line_reader string_view)
+
+#
+# tests
+#
+link_libraries(gtest gmock_main)
+
+## bit_utils_test
+add_executable(bit_utils_test bit_utils_test.cc)
+target_link_libraries(bit_utils_test)
+add_test(NAME bit_utils_test COMMAND bit_utils_test)
+##------------------------------------------------------------------------------
+## string_view_test
+add_executable(string_view_test string_view_test.cc ../src/string_view.c)
+target_link_libraries(string_view_test string_view)
+add_test(NAME string_view_test COMMAND string_view_test)
+##------------------------------------------------------------------------------
+## stack_line_reader_test
+add_executable(stack_line_reader_test stack_line_reader_test.cc)
+target_link_libraries(stack_line_reader_test stack_line_reader_for_test)
+add_test(NAME stack_line_reader_test COMMAND stack_line_reader_test)
+##------------------------------------------------------------------------------
+## linux_features_aggregator_test
+add_executable(linux_features_aggregator_test linux_features_aggregator_test.cc)
+target_link_libraries(linux_features_aggregator_test all_libraries)
+add_test(NAME linux_features_aggregator_test COMMAND linux_features_aggregator_test)
+##------------------------------------------------------------------------------
+## cpuinfo_x86_test
+add_executable(cpuinfo_x86_test cpuinfo_x86_test.cc ../src/cpuinfo_x86.c)
+target_link_libraries(cpuinfo_x86_test all_libraries)
+add_test(NAME cpuinfo_x86_test COMMAND cpuinfo_x86_test)
+##------------------------------------------------------------------------------
+## cpuinfo_arm_test
+add_executable(cpuinfo_arm_test cpuinfo_arm_test.cc ../src/cpuinfo_arm.c)
+target_link_libraries(cpuinfo_arm_test all_libraries)
+add_test(NAME cpuinfo_arm_test COMMAND cpuinfo_arm_test)
+##------------------------------------------------------------------------------
+## cpuinfo_aarch64_test
+add_executable(cpuinfo_aarch64_test cpuinfo_aarch64_test.cc ../src/cpuinfo_aarch64.c)
+target_link_libraries(cpuinfo_aarch64_test all_libraries)
+add_test(NAME cpuinfo_aarch64_test COMMAND cpuinfo_aarch64_test)
+##------------------------------------------------------------------------------
+## cpuinfo_mips_test
+add_executable(cpuinfo_mips_test cpuinfo_mips_test.cc  ../src/cpuinfo_mips.c)
+target_link_libraries(cpuinfo_mips_test all_libraries)
+add_test(NAME cpuinfo_mips_test COMMAND cpuinfo_mips_test)
+##------------------------------------------------------------------------------
+## cpuinfo_ppc_test
+add_executable(cpuinfo_ppc_test cpuinfo_ppc_test.cc  ../src/cpuinfo_ppc.c)
+target_link_libraries(cpuinfo_ppc_test all_libraries)
+add_test(NAME cpuinfo_ppc_test COMMAND cpuinfo_ppc_test)
--- a/external/cpu_features/test/bit_utils_test.cc
+++ b/external/cpu_features/test/bit_utils_test.cc
@ -0,0 +1,53 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/bit_utils.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+namespace {
+
+TEST(UtilsTest, IsBitSet) {
+  for (size_t bit_set = 0; bit_set < 32; ++bit_set) {
+    const uint32_t value = 1UL << bit_set;
+    for (size_t i = 0; i < 32; ++i) {
+      EXPECT_EQ(IsBitSet(value, i), i == bit_set);
+    }
+  }
+
+  // testing 0, all bits should be 0.
+  for (size_t i = 0; i < 32; ++i) {
+    EXPECT_FALSE(IsBitSet(0, i));
+  }
+
+  // testing ~0, all bits should be 1.
+  for (size_t i = 0; i < 32; ++i) {
+    EXPECT_TRUE(IsBitSet(-1, i));
+  }
+}
+
+TEST(UtilsTest, ExtractBitRange) {
+  // Extracting all bits gives the same number.
+  EXPECT_EQ(ExtractBitRange(123, 31, 0), 123);
+  // Extracting 1 bit gives parity.
+  EXPECT_EQ(ExtractBitRange(123, 0, 0), 1);
+  EXPECT_EQ(ExtractBitRange(122, 0, 0), 0);
+
+  EXPECT_EQ(ExtractBitRange(0xF0, 7, 4), 0xF);
+  EXPECT_EQ(ExtractBitRange(0x42 << 2, 10, 2), 0x42);
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/cpuinfo_aarch64_test.cc
+++ b/external/cpu_features/test/cpuinfo_aarch64_test.cc
@ -0,0 +1,74 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_aarch64.h"
+#include "filesystem_for_testing.h"
+#include "hwcaps_for_testing.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+namespace {
+
+void DisableHardwareCapabilities() { SetHardwareCapabilities(0, 0); }
+
+TEST(CpuinfoAarch64Test, FromHardwareCap) {
+  SetHardwareCapabilities(AARCH64_HWCAP_FP | AARCH64_HWCAP_AES, 0);
+  GetEmptyFilesystem();  // disabling /proc/cpuinfo
+  const auto info = GetAarch64Info();
+  EXPECT_TRUE(info.features.fp);
+  EXPECT_FALSE(info.features.asimd);
+  EXPECT_TRUE(info.features.aes);
+  EXPECT_FALSE(info.features.pmull);
+  EXPECT_FALSE(info.features.sha1);
+  EXPECT_FALSE(info.features.sha2);
+  EXPECT_FALSE(info.features.crc32);
+}
+
+TEST(CpuinfoAarch64Test, ARMCortexA53) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(Processor   : AArch64 Processor rev 3 (aarch64)
+processor   : 0
+processor   : 1
+processor   : 2
+processor   : 3
+processor   : 4
+processor   : 5
+processor   : 6
+processor   : 7
+Features    : fp asimd evtstrm aes pmull sha1 sha2 crc32
+CPU implementer : 0x41
+CPU architecture: AArch64
+CPU variant : 0x0
+CPU part    : 0xd03
+CPU revision    : 3)");
+  const auto info = GetAarch64Info();
+  EXPECT_EQ(info.implementer, 0x41);
+  EXPECT_EQ(info.variant, 0x0);
+  EXPECT_EQ(info.part, 0xd03);
+  EXPECT_EQ(info.revision, 3);
+
+  EXPECT_TRUE(info.features.fp);
+  EXPECT_TRUE(info.features.asimd);
+  EXPECT_TRUE(info.features.aes);
+  EXPECT_TRUE(info.features.pmull);
+  EXPECT_TRUE(info.features.sha1);
+  EXPECT_TRUE(info.features.sha2);
+  EXPECT_TRUE(info.features.crc32);
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/cpuinfo_arm_test.cc
+++ b/external/cpu_features/test/cpuinfo_arm_test.cc
@ -0,0 +1,182 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_arm.h"
+#include "filesystem_for_testing.h"
+#include "hwcaps_for_testing.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+namespace {
+
+void DisableHardwareCapabilities() { SetHardwareCapabilities(0, 0); }
+
+TEST(CpuinfoArmTest, FromHardwareCap) {
+  SetHardwareCapabilities(ARM_HWCAP_NEON, ARM_HWCAP2_AES | ARM_HWCAP2_CRC32);
+  GetEmptyFilesystem();  // disabling /proc/cpuinfo
+  const auto info = GetArmInfo();
+  EXPECT_TRUE(info.features.vfp);    // triggered by vfpv3
+  EXPECT_TRUE(info.features.vfpv3);  // triggered by neon
+  EXPECT_TRUE(info.features.neon);
+  EXPECT_TRUE(info.features.aes);
+  EXPECT_TRUE(info.features.crc32);
+
+  EXPECT_FALSE(info.features.vfpv4);
+  EXPECT_FALSE(info.features.iwmmxt);
+  EXPECT_FALSE(info.features.vfpv3d16);
+  EXPECT_FALSE(info.features.idiva);
+  EXPECT_FALSE(info.features.idivt);
+  EXPECT_FALSE(info.features.pmull);
+  EXPECT_FALSE(info.features.sha1);
+  EXPECT_FALSE(info.features.sha2);
+}
+
+TEST(CpuinfoArmTest, ODroidFromCpuInfo) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo", R"(processor       : 0
+model name      : ARMv7 Processor rev 3 (v71)
+BogoMIPS        : 120.00
+Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
+CPU implementer : 0x41
+CPU architecture: 7
+CPU variant     : 0x2
+CPU part        : 0xc0f
+CPU revision    : 3)");
+  const auto info = GetArmInfo();
+  EXPECT_EQ(info.implementer, 0x41);
+  EXPECT_EQ(info.variant, 0x2);
+  EXPECT_EQ(info.part, 0xc0f);
+  EXPECT_EQ(info.revision, 3);
+  EXPECT_EQ(info.architecture, 7);
+
+  EXPECT_TRUE(info.features.vfp);
+  EXPECT_FALSE(info.features.iwmmxt);
+  EXPECT_TRUE(info.features.neon);
+  EXPECT_TRUE(info.features.vfpv3);
+  EXPECT_FALSE(info.features.vfpv3d16);
+  EXPECT_TRUE(info.features.vfpv4);
+  EXPECT_TRUE(info.features.idiva);
+  EXPECT_TRUE(info.features.idivt);
+  EXPECT_FALSE(info.features.aes);
+  EXPECT_FALSE(info.features.pmull);
+  EXPECT_FALSE(info.features.sha1);
+  EXPECT_FALSE(info.features.sha2);
+  EXPECT_FALSE(info.features.crc32);
+}
+
+// http://code.google.com/p/android/issues/detail?id=10812
+TEST(CpuinfoArmTest, InvalidArmv7) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(Processor       : ARMv6-compatible processor rev 6 (v6l) 
+BogoMIPS        : 199.47 
+Features        : swp half thumb fastmult vfp edsp java 
+CPU implementer : 0x41 
+CPU architecture: 7 
+CPU variant     : 0x0 
+CPU part        : 0xb76 
+CPU revision    : 6 
+
+Hardware        : SPICA 
+Revision        : 0020 
+Serial          : 33323613546d00ec )");
+  const auto info = GetArmInfo();
+  EXPECT_EQ(info.architecture, 6);
+}
+
+// https://crbug.com/341598.
+TEST(CpuinfoArmTest, InvalidNeon) {
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(Processor: ARMv7 Processory rev 0 (v71)
+processor: 0
+BogoMIPS: 13.50
+
+Processor: 1
+BogoMIPS: 13.50
+
+Features: swp half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt
+CPU implementer : 0x51
+CPU architecture: 7
+CPU variant: 0x1
+CPU part: 0x04d
+CPU revision: 0
+
+Hardware: SAMSUNG M2
+Revision: 0010
+Serial: 00001e030000354e)");
+  const auto info = GetArmInfo();
+  EXPECT_FALSE(info.features.neon);
+}
+
+// The Nexus 4 (Qualcomm Krait) kernel configuration forgets to report IDIV
+// support.
+TEST(CpuinfoArmTest, Nexus4_0x510006f2) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(CPU implementer	: 0x51
+CPU architecture: 7
+CPU variant	: 0x0
+CPU part	: 0x6f
+CPU revision	: 2)");
+  const auto info = GetArmInfo();
+  EXPECT_TRUE(info.features.idiva);
+  EXPECT_TRUE(info.features.idivt);
+}
+
+// The Nexus 4 (Qualcomm Krait) kernel configuration forgets to report IDIV
+// support.
+TEST(CpuinfoArmTest, Nexus4_0x510006f3) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(CPU implementer	: 0x51
+CPU architecture: 7
+CPU variant	: 0x0
+CPU part	: 0x6f
+CPU revision	: 3)");
+  const auto info = GetArmInfo();
+  EXPECT_TRUE(info.features.idiva);
+  EXPECT_TRUE(info.features.idivt);
+}
+
+// The emulator-specific Android 4.2 kernel fails to report support for the
+// 32-bit ARM IDIV instruction. Technically, this is a feature of the virtual
+// CPU implemented by the emulator.
+TEST(CpuinfoArmTest, EmulatorSpecificIdiv) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(Processor	: ARMv7 Processor rev 0 (v7l)
+BogoMIPS	: 629.14
+Features	: swp half thumb fastmult vfp edsp neon vfpv3
+CPU implementer	: 0x41
+CPU architecture: 7
+CPU variant	: 0x0
+CPU part	: 0xc08
+CPU revision	: 0
+
+Hardware	: Goldfish
+Revision	: 0000
+Serial		: 0000000000000000)");
+  const auto info = GetArmInfo();
+  EXPECT_TRUE(info.features.idiva);
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/cpuinfo_mips_test.cc
+++ b/external/cpu_features/test/cpuinfo_mips_test.cc
@ -0,0 +1,125 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "cpuinfo_mips.h"
+#include "filesystem_for_testing.h"
+#include "hwcaps_for_testing.h"
+#include "internal/stack_line_reader.h"
+#include "internal/string_view.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+
+namespace {
+
+void DisableHardwareCapabilities() { SetHardwareCapabilities(0, 0); }
+
+TEST(CpuinfoMipsTest, FromHardwareCapBoth) {
+  SetHardwareCapabilities(MIPS_HWCAP_EVA | MIPS_HWCAP_MSA, 0);
+  GetEmptyFilesystem();  // disabling /proc/cpuinfo
+  const auto info = GetMipsInfo();
+  EXPECT_TRUE(info.features.msa);
+  EXPECT_TRUE(info.features.eva);
+}
+
+TEST(CpuinfoMipsTest, FromHardwareCapOnlyOne) {
+  SetHardwareCapabilities(MIPS_HWCAP_MSA, 0);
+  GetEmptyFilesystem();  // disabling /proc/cpuinfo
+  const auto info = GetMipsInfo();
+  EXPECT_TRUE(info.features.msa);
+  EXPECT_FALSE(info.features.eva);
+}
+
+TEST(CpuinfoMipsTest, Ci40) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo", R"(system type : IMG Pistachio SoC (B0)
+machine : IMG Marduk – Ci40 with cc2520
+processor : 0
+cpu model : MIPS interAptiv (multi) V2.0 FPU V0.0
+BogoMIPS : 363.72
+wait instruction : yes
+microsecond timers : yes
+tlb_entries : 64
+extra interrupt vector : yes
+hardware watchpoint : yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
+isa : mips1 mips2 mips32r1 mips32r2
+ASEs implemented : mips16 dsp mt eva
+shadow register sets : 1
+kscratch registers : 0
+package : 0
+core : 0
+VCED exceptions : not available
+VCEI exceptions : not available
+VPE : 0
+)");
+  const auto info = GetMipsInfo();
+  EXPECT_FALSE(info.features.msa);
+  EXPECT_TRUE(info.features.eva);
+}
+
+TEST(CpuinfoMipsTest, AR7161) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(system type             : Atheros AR7161 rev 2
+machine                 : NETGEAR WNDR3700/WNDR3800/WNDRMAC
+processor               : 0
+cpu model               : MIPS 24Kc V7.4
+BogoMIPS                : 452.19
+wait instruction        : yes
+microsecond timers      : yes
+tlb_entries             : 16
+extra interrupt vector  : yes
+hardware watchpoint     : yes, count: 4, address/irw mask: [0x0000, 0x0f98, 0x0f78, 0x0df8]
+ASEs implemented        : mips16
+shadow register sets    : 1
+kscratch registers      : 0
+core                    : 0
+VCED exceptions         : not available
+VCEI exceptions         : not available
+)");
+  const auto info = GetMipsInfo();
+  EXPECT_FALSE(info.features.msa);
+  EXPECT_FALSE(info.features.eva);
+}
+
+TEST(CpuinfoMipsTest, Goldfish) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo", R"(system type		: MIPS-Goldfish
+Hardware		: goldfish
+Revison		: 1
+processor		: 0
+cpu model		: MIPS 24Kc V0.0  FPU V0.0
+BogoMIPS		: 1042.02
+wait instruction	: yes
+microsecond timers	: yes
+tlb_entries		: 16
+extra interrupt vector	: yes
+hardware watchpoint	: yes, count: 1, address/irw mask: [0x0ff8]
+ASEs implemented	:
+shadow register sets	: 1
+core			: 0
+VCED exceptions		: not available
+VCEI exceptions		: not available
+)");
+  const auto info = GetMipsInfo();
+  EXPECT_FALSE(info.features.msa);
+  EXPECT_FALSE(info.features.eva);
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/cpuinfo_ppc_test.cc
+++ b/external/cpu_features/test/cpuinfo_ppc_test.cc
@ -0,0 +1,119 @@
+// Copyright 2018 IBM.
+//
+// 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 "cpuinfo_ppc.h"
+#include "filesystem_for_testing.h"
+#include "hwcaps_for_testing.h"
+#include "internal/string_view.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+namespace {
+
+void DisableHardwareCapabilities() { SetHardwareCapabilities(0, 0); }
+
+TEST(CpustringsPPCTest, FromHardwareCap) {
+  SetHardwareCapabilities(PPC_FEATURE_HAS_FPU | PPC_FEATURE_HAS_VSX,
+                          PPC_FEATURE2_ARCH_3_00);
+  GetEmptyFilesystem();  // disabling /proc/cpuinfo
+  const auto info = GetPPCInfo();
+  EXPECT_TRUE(info.features.fpu);
+  EXPECT_FALSE(info.features.mmu);
+  EXPECT_TRUE(info.features.vsx);
+  EXPECT_TRUE(info.features.arch300);
+  EXPECT_FALSE(info.features.power4);
+  EXPECT_FALSE(info.features.altivec);
+  EXPECT_FALSE(info.features.vcrypto);
+  EXPECT_FALSE(info.features.htm);
+}
+
+TEST(CpustringsPPCTest, Blade) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(processor       : 14
+cpu             : POWER7 (architected), altivec supported
+clock           : 3000.000000MHz
+revision        : 2.1 (pvr 003f 0201)
+
+processor       : 15
+cpu             : POWER7 (architected), altivec supported
+clock           : 3000.000000MHz
+revision        : 2.1 (pvr 003f 0201)
+
+timebase        : 512000000
+platform        : pSeries
+model           : IBM,8406-70Y
+machine         : CHRP IBM,8406-70Y)");
+  SetPlatformTypes("power7", "power8");
+  const auto strings = GetPPCPlatformStrings();
+  ASSERT_STREQ(strings.platform, "pSeries");
+  ASSERT_STREQ(strings.model, "IBM,8406-70Y");
+  ASSERT_STREQ(strings.machine, "CHRP IBM,8406-70Y");
+  ASSERT_STREQ(strings.cpu, "POWER7 (architected), altivec supported");
+  ASSERT_STREQ(strings.type.platform, "power7");
+  ASSERT_STREQ(strings.type.base_platform, "power8");
+}
+
+TEST(CpustringsPPCTest, Firestone) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(processor       : 126
+cpu             : POWER8 (raw), altivec supported
+clock           : 2061.000000MHz
+revision        : 2.0 (pvr 004d 0200)
+
+processor       : 127
+cpu             : POWER8 (raw), altivec supported
+clock           : 2061.000000MHz
+revision        : 2.0 (pvr 004d 0200)
+
+timebase        : 512000000
+platform        : PowerNV
+model           : 8335-GTA
+machine         : PowerNV 8335-GTA
+firmware        : OPAL v3)");
+  const auto strings = GetPPCPlatformStrings();
+  ASSERT_STREQ(strings.platform, "PowerNV");
+  ASSERT_STREQ(strings.model, "8335-GTA");
+  ASSERT_STREQ(strings.machine, "PowerNV 8335-GTA");
+  ASSERT_STREQ(strings.cpu, "POWER8 (raw), altivec supported");
+}
+
+TEST(CpustringsPPCTest, w8) {
+  DisableHardwareCapabilities();
+  auto& fs = GetEmptyFilesystem();
+  fs.CreateFile("/proc/cpuinfo",
+                R"(processor       : 143
+cpu             : POWER9, altivec supported
+clock           : 2300.000000MHz
+revision        : 2.2 (pvr 004e 1202)
+
+timebase        : 512000000
+platform        : PowerNV
+model           : 0000000000000000
+machine         : PowerNV 0000000000000000
+firmware        : OPAL
+MMU             : Radix)");
+  const auto strings = GetPPCPlatformStrings();
+  ASSERT_STREQ(strings.platform, "PowerNV");
+  ASSERT_STREQ(strings.model, "0000000000000000");
+  ASSERT_STREQ(strings.machine, "PowerNV 0000000000000000");
+  ASSERT_STREQ(strings.cpu, "POWER9, altivec supported");
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/cpuinfo_x86_test.cc
+++ b/external/cpu_features/test/cpuinfo_x86_test.cc
@ -0,0 +1,172 @@
+// Copyright 2017 Google Inc.
+//
+// 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 <cassert>
+#include <cstdio>
+#include <map>
+
+#include "gtest/gtest.h"
+
+#include "cpuinfo_x86.h"
+#include "internal/cpuid_x86.h"
+
+namespace cpu_features {
+
+class FakeCpu {
+ public:
+  Leaf CpuId(uint32_t leaf_id) const {
+    const auto itr = cpuid_leaves_.find(leaf_id);
+    EXPECT_TRUE(itr != cpuid_leaves_.end()) << "Missing leaf " << leaf_id;
+    return itr->second;
+  }
+
+  uint32_t GetXCR0Eax() const { return xcr0_eax_; }
+
+  void SetLeaves(std::map<uint32_t, Leaf> configuration) {
+    cpuid_leaves_ = std::move(configuration);
+  }
+
+  void SetOsBackupsExtendedRegisters(bool os_backups_extended_registers) {
+    xcr0_eax_ = os_backups_extended_registers ? -1 : 0;
+  }
+
+ private:
+  std::map<uint32_t, Leaf> cpuid_leaves_;
+  uint32_t xcr0_eax_;
+};
+
+auto* g_fake_cpu = new FakeCpu();
+
+extern "C" Leaf CpuId(uint32_t leaf_id) { return g_fake_cpu->CpuId(leaf_id); }
+extern "C" uint32_t GetXCR0Eax(void) { return g_fake_cpu->GetXCR0Eax(); }
+
+namespace {
+
+TEST(CpuidX86Test, SandyBridge) {
+  g_fake_cpu->SetOsBackupsExtendedRegisters(true);
+  g_fake_cpu->SetLeaves({
+      {0x00000000, Leaf{0x0000000D, 0x756E6547, 0x6C65746E, 0x49656E69}},
+      {0x00000001, Leaf{0x000206A6, 0x00100800, 0x1F9AE3BF, 0xBFEBFBFF}},
+      {0x00000007, Leaf{0x00000000, 0x00000000, 0x00000000, 0x00000000}},
+  });
+  const auto info = GetX86Info();
+  EXPECT_STREQ(info.vendor, "GenuineIntel");
+  EXPECT_EQ(info.family, 0x06);
+  EXPECT_EQ(info.model, 0x02A);
+  EXPECT_EQ(info.stepping, 0x06);
+  // Leaf 7 is zeroed out so none of the Leaf 7 flags are set.
+  const auto features = info.features;
+  EXPECT_FALSE(features.erms);
+  EXPECT_FALSE(features.avx2);
+  EXPECT_FALSE(features.avx512f);
+  EXPECT_FALSE(features.avx512cd);
+  EXPECT_FALSE(features.avx512er);
+  EXPECT_FALSE(features.avx512pf);
+  EXPECT_FALSE(features.avx512bw);
+  EXPECT_FALSE(features.avx512dq);
+  EXPECT_FALSE(features.avx512vl);
+  EXPECT_FALSE(features.avx512ifma);
+  EXPECT_FALSE(features.avx512vbmi);
+  EXPECT_FALSE(features.avx512vbmi2);
+  EXPECT_FALSE(features.avx512vnni);
+  EXPECT_FALSE(features.avx512bitalg);
+  EXPECT_FALSE(features.avx512vpopcntdq);
+  EXPECT_FALSE(features.avx512_4vnniw);
+  EXPECT_FALSE(features.avx512_4vbmi2);
+  // All old cpu features should be set.
+  EXPECT_TRUE(features.aes);
+  EXPECT_TRUE(features.ssse3);
+  EXPECT_TRUE(features.sse4_1);
+  EXPECT_TRUE(features.sse4_2);
+  EXPECT_TRUE(features.avx);
+}
+
+TEST(CpuidX86Test, SandyBridgeTestOsSupport) {
+  g_fake_cpu->SetLeaves({
+      {0x00000000, Leaf{0x0000000D, 0x756E6547, 0x6C65746E, 0x49656E69}},
+      {0x00000001, Leaf{0x000206A6, 0x00100800, 0x1F9AE3BF, 0xBFEBFBFF}},
+      {0x00000007, Leaf{0x00000000, 0x00000000, 0x00000000, 0x00000000}},
+  });
+  // avx is disabled if os does not support backing up ymm registers.
+  g_fake_cpu->SetOsBackupsExtendedRegisters(false);
+  EXPECT_FALSE(GetX86Info().features.avx);
+  // avx is disabled if os does not support backing up ymm registers.
+  g_fake_cpu->SetOsBackupsExtendedRegisters(true);
+  EXPECT_TRUE(GetX86Info().features.avx);
+}
+
+TEST(CpuidX86Test, SkyLake) {
+  g_fake_cpu->SetOsBackupsExtendedRegisters(true);
+  g_fake_cpu->SetLeaves({
+      {0x00000000, Leaf{0x00000016, 0x756E6547, 0x6C65746E, 0x49656E69}},
+      {0x00000001, Leaf{0x000406E3, 0x00100800, 0x7FFAFBBF, 0xBFEBFBFF}},
+      {0x00000007, Leaf{0x00000000, 0x029C67AF, 0x00000000, 0x00000000}},
+  });
+  const auto info = GetX86Info();
+  EXPECT_STREQ(info.vendor, "GenuineIntel");
+  EXPECT_EQ(info.family, 0x06);
+  EXPECT_EQ(info.model, 0x04E);
+  EXPECT_EQ(info.stepping, 0x03);
+  EXPECT_EQ(GetX86Microarchitecture(&info), X86Microarchitecture::INTEL_SKL);
+}
+
+TEST(CpuidX86Test, Branding) {
+  g_fake_cpu->SetLeaves({
+      {0x00000000, Leaf{0x00000016, 0x756E6547, 0x6C65746E, 0x49656E69}},
+      {0x00000001, Leaf{0x000406E3, 0x00100800, 0x7FFAFBBF, 0xBFEBFBFF}},
+      {0x00000007, Leaf{0x00000000, 0x029C67AF, 0x00000000, 0x00000000}},
+      {0x80000000, Leaf{0x80000008, 0x00000000, 0x00000000, 0x00000000}},
+      {0x80000001, Leaf{0x00000000, 0x00000000, 0x00000121, 0x2C100000}},
+      {0x80000002, Leaf{0x65746E49, 0x2952286C, 0x726F4320, 0x4D542865}},
+      {0x80000003, Leaf{0x37692029, 0x3035362D, 0x43205530, 0x40205550}},
+      {0x80000004, Leaf{0x352E3220, 0x7A484730, 0x00000000, 0x00000000}},
+  });
+  char brand_string[49];
+  FillX86BrandString(brand_string);
+  EXPECT_STREQ(brand_string, "Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz");
+}
+
+// http://users.atw.hu/instlatx64/AuthenticAMD0630F81_K15_Godavari_CPUID.txt
+TEST(CpuidX86Test, AMD_K15) {
+  g_fake_cpu->SetLeaves({
+      {0x00000000, Leaf{0x0000000D, 0x68747541, 0x444D4163, 0x69746E65}},
+      {0x00000001, Leaf{0x00630F81, 0x00040800, 0x3E98320B, 0x178BFBFF}},
+      {0x00000007, Leaf{0x00000000, 0x00000000, 0x00000000, 0x00000000}},
+      {0x80000000, Leaf{0x8000001E, 0x68747541, 0x444D4163, 0x69746E65}},
+      {0x80000001, Leaf{0x00630F81, 0x10000000, 0x0FEBBFFF, 0x2FD3FBFF}},
+      {0x80000002, Leaf{0x20444D41, 0x372D3841, 0x4B303736, 0x64615220}},
+      {0x80000003, Leaf{0x206E6F65, 0x202C3752, 0x43203031, 0x75706D6F}},
+      {0x80000004, Leaf{0x43206574, 0x7365726F, 0x2B433420, 0x00204736}},
+      {0x80000005, Leaf{0xFF40FF18, 0xFF40FF30, 0x10040140, 0x60030140}},
+  });
+  const auto info = GetX86Info();
+
+  EXPECT_STREQ(info.vendor, "AuthenticAMD");
+  EXPECT_EQ(info.family, 0x15);
+  EXPECT_EQ(info.model, 0x38);
+  EXPECT_EQ(info.stepping, 0x01);
+  EXPECT_EQ(GetX86Microarchitecture(&info),
+            X86Microarchitecture::AMD_BULLDOZER);
+
+  char brand_string[49];
+  FillX86BrandString(brand_string);
+  EXPECT_STREQ(brand_string, "AMD A8-7670K Radeon R7, 10 Compute Cores 4C+6G ");
+}
+
+// TODO(user): test what happens when xsave/osxsave are not present.
+// TODO(user): test what happens when xmm/ymm/zmm os support are not
+// present.
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/filesystem_for_testing.cc
+++ b/external/cpu_features/test/filesystem_for_testing.cc
@ -0,0 +1,103 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "filesystem_for_testing.h"
+
+#include <cassert>
+#include <climits>
+#include <cstdio>
+#include <cstring>
+#include <utility>
+
+namespace cpu_features {
+
+FakeFile::FakeFile(int file_descriptor, const char* content)
+    : file_descriptor_(file_descriptor), content_(content) {}
+
+FakeFile::~FakeFile() { assert(!opened_); }
+
+void FakeFile::Open() {
+  assert(!opened_);
+  opened_ = true;
+}
+
+void FakeFile::Close() {
+  assert(opened_);
+  opened_ = false;
+}
+
+int FakeFile::Read(int fd, void* buf, size_t count) {
+  assert(count < INT_MAX);
+  assert(fd == file_descriptor_);
+  const size_t remainder = content_.size() - head_index_;
+  const size_t read = count > remainder ? remainder : count;
+  memcpy(buf, content_.data() + head_index_, read);
+  head_index_ += read;
+  assert(read < INT_MAX);
+  return read;
+}
+
+void FakeFilesystem::Reset() { files_.clear(); }
+
+FakeFile* FakeFilesystem::CreateFile(const std::string& filename,
+                                     const char* content) {
+  auto& file = files_[filename];
+  file =
+      std::unique_ptr<FakeFile>(new FakeFile(next_file_descriptor_++, content));
+  return file.get();
+}
+
+FakeFile* FakeFilesystem::FindFileOrNull(const std::string& filename) const {
+  const auto itr = files_.find(filename);
+  return itr == files_.end() ? nullptr : itr->second.get();
+}
+
+FakeFile* FakeFilesystem::FindFileOrDie(const int file_descriptor) const {
+  for (const auto& filename_file_pair : files_) {
+    FakeFile* const file_ptr = filename_file_pair.second.get();
+    if (file_ptr->GetFileDescriptor() == file_descriptor) {
+      return file_ptr;
+    }
+  }
+  assert(false);
+  return nullptr;
+}
+
+static FakeFilesystem* kFilesystem = new FakeFilesystem();
+
+FakeFilesystem& GetEmptyFilesystem() {
+  kFilesystem->Reset();
+  return *kFilesystem;
+}
+
+extern "C" int CpuFeatures_OpenFile(const char* filename) {
+  auto* const file = kFilesystem->FindFileOrNull(filename);
+  if (file) {
+    file->Open();
+    return file->GetFileDescriptor();
+  }
+  return -1;
+}
+
+extern "C" void CpuFeatures_CloseFile(int file_descriptor) {
+  kFilesystem->FindFileOrDie(file_descriptor)->Close();
+}
+
+extern "C" int CpuFeatures_ReadFile(int file_descriptor, void* buffer,
+                                    size_t buffer_size) {
+  return kFilesystem->FindFileOrDie(file_descriptor)
+      ->Read(file_descriptor, buffer, buffer_size);
+}
+
+}  // namespace cpu_features
--- a/external/cpu_features/test/filesystem_for_testing.h
+++ b/external/cpu_features/test/filesystem_for_testing.h
@ -0,0 +1,61 @@
+// Copyright 2017 Google Inc.
+//
+// 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.
+
+// Implements a fake filesystem, useful for tests.
+#ifndef CPU_FEATURES_TEST_FILESYSTEM_FOR_TESTING_H_
+#define CPU_FEATURES_TEST_FILESYSTEM_FOR_TESTING_H_
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+#include "internal/filesystem.h"
+
+namespace cpu_features {
+
+class FakeFile {
+ public:
+  explicit FakeFile(int file_descriptor, const char* content);
+  ~FakeFile();
+
+  void Open();
+  void Close();
+  int Read(int fd, void* buf, size_t count);
+
+  int GetFileDescriptor() const { return file_descriptor_; }
+
+ private:
+  const int file_descriptor_;
+  const std::string content_;
+  bool opened_ = false;
+  size_t head_index_ = 0;
+};
+
+class FakeFilesystem {
+ public:
+  void Reset();
+  FakeFile* CreateFile(const std::string& filename, const char* content);
+  FakeFile* FindFileOrDie(const int file_descriptor) const;
+  FakeFile* FindFileOrNull(const std::string& filename) const;
+
+ private:
+  size_t next_file_descriptor_ = 0;
+  std::unordered_map<std::string, std::unique_ptr<FakeFile>> files_;
+};
+
+FakeFilesystem& GetEmptyFilesystem();
+
+}  // namespace cpu_features
+
+#endif  // CPU_FEATURES_TEST_FILESYSTEM_FOR_TESTING_H_
--- a/external/cpu_features/test/hwcaps_for_testing.cc
+++ b/external/cpu_features/test/hwcaps_for_testing.cc
@ -0,0 +1,45 @@
+// Copyright 2017 Google Inc.
+//
+// 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 <string.h>
+
+#include "hwcaps_for_testing.h"
+#include "internal/string_view.h"
+
+namespace cpu_features {
+
+namespace {
+static auto* const g_hardware_capabilities = new HardwareCapabilities();
+static auto* const g_platform_types = new PlatformType();
+}  // namespace
+
+void SetHardwareCapabilities(uint32_t hwcaps, uint32_t hwcaps2) {
+  g_hardware_capabilities->hwcaps = hwcaps;
+  g_hardware_capabilities->hwcaps2 = hwcaps2;
+}
+
+HardwareCapabilities CpuFeatures_GetHardwareCapabilities(void) {
+  return *g_hardware_capabilities;
+}
+
+void SetPlatformTypes(const char* platform, const char* base_platform) {
+  CpuFeatures_StringView_CopyString(str(platform), g_platform_types->platform,
+                                    sizeof(g_platform_types->platform));
+  CpuFeatures_StringView_CopyString(str(base_platform),
+                                    g_platform_types->base_platform,
+                                    sizeof(g_platform_types->base_platform));
+}
+
+PlatformType CpuFeatures_GetPlatformType(void) { return *g_platform_types; }
+}  // namespace cpu_features
--- a/external/cpu_features/test/hwcaps_for_testing.h
+++ b/external/cpu_features/test/hwcaps_for_testing.h
@ -0,0 +1,27 @@
+// Copyright 2017 Google Inc.
+//
+// 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 CPU_FEATURES_TEST_HWCAPS_FOR_TESTING_H_
+#define CPU_FEATURES_TEST_HWCAPS_FOR_TESTING_H_
+
+#include "internal/hwcaps.h"
+
+namespace cpu_features {
+
+void SetHardwareCapabilities(uint32_t hwcaps, uint32_t hwcaps2);
+void SetPlatformTypes(const char *platform, const char *base_platform);
+
+}  // namespace cpu_features
+
+#endif  // CPU_FEATURES_TEST_HWCAPS_FOR_TESTING_H_
--- a/external/cpu_features/test/linux_features_aggregator_test.cc
+++ b/external/cpu_features/test/linux_features_aggregator_test.cc
@ -0,0 +1,95 @@
+// Copyright 2017 Google Inc.
+//
+// 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 <array>
+
+#include "internal/linux_features_aggregator.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+
+namespace {
+
+struct Features {
+  bool a = false;
+  bool b = false;
+  bool c = false;
+};
+
+DECLARE_SETTER(Features, a)
+DECLARE_SETTER(Features, b)
+DECLARE_SETTER(Features, c)
+
+class LinuxFeatureAggregatorTest : public testing::Test {
+ public:
+  const std::array<CapabilityConfig, 3> kConfigs = {
+      {{{0b0001, 0b0000}, "a", &set_a},
+       {{0b0010, 0b0000}, "b", &set_b},
+       {{0b0000, 0b1100}, "c", &set_c}}};
+};
+
+TEST_F(LinuxFeatureAggregatorTest, FromFlagsEmpty) {
+  Features features;
+  CpuFeatures_SetFromFlags(kConfigs.size(), kConfigs.data(), str(""),
+                           &features);
+  EXPECT_FALSE(features.a);
+  EXPECT_FALSE(features.b);
+  EXPECT_FALSE(features.c);
+}
+
+TEST_F(LinuxFeatureAggregatorTest, FromFlagsAllSet) {
+  Features features;
+  CpuFeatures_SetFromFlags(kConfigs.size(), kConfigs.data(), str("a c b"),
+                           &features);
+  EXPECT_TRUE(features.a);
+  EXPECT_TRUE(features.b);
+  EXPECT_TRUE(features.c);
+}
+
+TEST_F(LinuxFeatureAggregatorTest, FromFlagsOnlyA) {
+  Features features;
+  CpuFeatures_SetFromFlags(kConfigs.size(), kConfigs.data(), str("a"),
+                           &features);
+  EXPECT_TRUE(features.a);
+  EXPECT_FALSE(features.b);
+  EXPECT_FALSE(features.c);
+}
+
+TEST_F(LinuxFeatureAggregatorTest, FromHwcapsNone) {
+  HardwareCapabilities capability;
+  capability.hwcaps = 0;   // matches none
+  capability.hwcaps2 = 0;  // matches none
+  Features features;
+  CpuFeatures_OverrideFromHwCaps(kConfigs.size(), kConfigs.data(), capability,
+                                 &features);
+  EXPECT_FALSE(features.a);
+  EXPECT_FALSE(features.b);
+  EXPECT_FALSE(features.c);
+}
+
+TEST_F(LinuxFeatureAggregatorTest, FromHwcapsSet) {
+  HardwareCapabilities capability;
+  capability.hwcaps = 0b0010;   // matches b but not a
+  capability.hwcaps2 = 0b1111;  // matches c
+  Features features;
+  CpuFeatures_OverrideFromHwCaps(kConfigs.size(), kConfigs.data(), capability,
+                                 &features);
+  EXPECT_FALSE(features.a);
+  EXPECT_TRUE(features.b);
+  EXPECT_TRUE(features.c);
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/stack_line_reader_test.cc
+++ b/external/cpu_features/test/stack_line_reader_test.cc
@ -0,0 +1,132 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/stack_line_reader.h"
+#include "filesystem_for_testing.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+
+bool operator==(const StringView& a, const StringView& b) {
+  return CpuFeatures_StringView_IsEquals(a, b);
+}
+
+namespace {
+
+std::string ToString(StringView view) { return {view.ptr, view.size}; }
+
+TEST(StackLineReaderTest, Empty) {
+  auto& fs = GetEmptyFilesystem();
+  auto* file = fs.CreateFile("/proc/cpuinfo", "");
+  StackLineReader reader;
+  StackLineReader_Initialize(&reader, file->GetFileDescriptor());
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_TRUE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str(""));
+  }
+}
+
+TEST(StackLineReaderTest, ManySmallLines) {
+  auto& fs = GetEmptyFilesystem();
+  auto* file = fs.CreateFile("/proc/cpuinfo", "a\nb\nc");
+
+  StackLineReader reader;
+  StackLineReader_Initialize(&reader, file->GetFileDescriptor());
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str("a"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str("b"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_TRUE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str("c"));
+  }
+}
+
+TEST(StackLineReaderTest, TruncatedLine) {
+  auto& fs = GetEmptyFilesystem();
+  auto* file = fs.CreateFile("/proc/cpuinfo", R"(First
+Second
+More than 16 characters, this will be truncated.
+last)");
+
+  StackLineReader reader;
+  StackLineReader_Initialize(&reader, file->GetFileDescriptor());
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str("First"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str("Second"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_FALSE(result.full_line);
+    EXPECT_EQ(result.line, str("More than 16 cha"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_TRUE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str("last"));
+  }
+}
+
+TEST(StackLineReaderTest, TruncatedLines) {
+  auto& fs = GetEmptyFilesystem();
+  auto* file = fs.CreateFile("/proc/cpuinfo", R"(More than 16 characters
+Another line that is too long)");
+
+  StackLineReader reader;
+  StackLineReader_Initialize(&reader, file->GetFileDescriptor());
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_FALSE(result.full_line);
+    EXPECT_EQ(result.line, str("More than 16 cha"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_FALSE(result.eof);
+    EXPECT_FALSE(result.full_line);
+    EXPECT_EQ(result.line, str("Another line tha"));
+  }
+  {
+    const auto result = StackLineReader_NextLine(&reader);
+    EXPECT_TRUE(result.eof);
+    EXPECT_TRUE(result.full_line);
+    EXPECT_EQ(result.line, str(""));
+  }
+}
+
+}  // namespace
+}  // namespace cpu_features
--- a/external/cpu_features/test/string_view_test.cc
+++ b/external/cpu_features/test/string_view_test.cc
@ -0,0 +1,144 @@
+// Copyright 2017 Google Inc.
+//
+// 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 "internal/string_view.h"
+
+#include "gtest/gtest.h"
+
+namespace cpu_features {
+
+bool operator==(const StringView& a, const StringView& b) {
+  return CpuFeatures_StringView_IsEquals(a, b);
+}
+
+namespace {
+
+TEST(StringViewTest, Empty) {
+  EXPECT_EQ(kEmptyStringView.ptr, nullptr);
+  EXPECT_EQ(kEmptyStringView.size, 0);
+}
+
+TEST(StringViewTest, Build) {
+  const auto view = str("test");
+  EXPECT_EQ(view.ptr[0], 't');
+  EXPECT_EQ(view.size, 4);
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_IndexOfChar) {
+  // Found.
+  EXPECT_EQ(CpuFeatures_StringView_IndexOfChar(str("test"), 'e'), 1);
+  // Not found.
+  EXPECT_EQ(CpuFeatures_StringView_IndexOfChar(str("test"), 'z'), -1);
+  // Empty.
+  EXPECT_EQ(CpuFeatures_StringView_IndexOfChar(kEmptyStringView, 'z'), -1);
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_IndexOf) {
+  // Found.
+  EXPECT_EQ(CpuFeatures_StringView_IndexOf(str("test"), str("es")), 1);
+  // Not found.
+  EXPECT_EQ(CpuFeatures_StringView_IndexOf(str("test"), str("aa")), -1);
+  // Empty.
+  EXPECT_EQ(CpuFeatures_StringView_IndexOf(kEmptyStringView, str("aa")), -1);
+  EXPECT_EQ(CpuFeatures_StringView_IndexOf(str("aa"), kEmptyStringView), -1);
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_StartsWith) {
+  EXPECT_TRUE(CpuFeatures_StringView_StartsWith(str("test"), str("te")));
+  EXPECT_FALSE(CpuFeatures_StringView_StartsWith(str("test"), str("")));
+  EXPECT_FALSE(
+      CpuFeatures_StringView_StartsWith(str("test"), kEmptyStringView));
+  EXPECT_FALSE(
+      CpuFeatures_StringView_StartsWith(kEmptyStringView, str("test")));
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_IsEquals) {
+  EXPECT_TRUE(
+      CpuFeatures_StringView_IsEquals(kEmptyStringView, kEmptyStringView));
+  EXPECT_TRUE(CpuFeatures_StringView_IsEquals(kEmptyStringView, str("")));
+  EXPECT_TRUE(CpuFeatures_StringView_IsEquals(str(""), kEmptyStringView));
+  EXPECT_TRUE(CpuFeatures_StringView_IsEquals(str("a"), str("a")));
+  EXPECT_FALSE(CpuFeatures_StringView_IsEquals(str("a"), str("b")));
+  EXPECT_FALSE(CpuFeatures_StringView_IsEquals(str("a"), kEmptyStringView));
+  EXPECT_FALSE(CpuFeatures_StringView_IsEquals(kEmptyStringView, str("a")));
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_PopFront) {
+  EXPECT_EQ(CpuFeatures_StringView_PopFront(str("test"), 2), str("st"));
+  EXPECT_EQ(CpuFeatures_StringView_PopFront(str("test"), 0), str("test"));
+  EXPECT_EQ(CpuFeatures_StringView_PopFront(str("test"), 4), str(""));
+  EXPECT_EQ(CpuFeatures_StringView_PopFront(str("test"), 100), str(""));
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_ParsePositiveNumber) {
+  EXPECT_EQ(CpuFeatures_StringView_ParsePositiveNumber(str("42")), 42);
+  EXPECT_EQ(CpuFeatures_StringView_ParsePositiveNumber(str("0x2a")), 42);
+  EXPECT_EQ(CpuFeatures_StringView_ParsePositiveNumber(str("0x2A")), 42);
+
+  EXPECT_EQ(CpuFeatures_StringView_ParsePositiveNumber(str("-0x2A")), -1);
+  EXPECT_EQ(CpuFeatures_StringView_ParsePositiveNumber(str("abc")), -1);
+  EXPECT_EQ(CpuFeatures_StringView_ParsePositiveNumber(str("")), -1);
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_CopyString) {
+  char buf[4];
+  buf[0] = 'X';
+
+  // Empty
+  CpuFeatures_StringView_CopyString(str(""), buf, sizeof(buf));
+  EXPECT_STREQ(buf, "");
+
+  // Less
+  CpuFeatures_StringView_CopyString(str("a"), buf, sizeof(buf));
+  EXPECT_STREQ(buf, "a");
+
+  // exact
+  CpuFeatures_StringView_CopyString(str("abc"), buf, sizeof(buf));
+  EXPECT_STREQ(buf, "abc");
+
+  // More
+  CpuFeatures_StringView_CopyString(str("abcd"), buf, sizeof(buf));
+  EXPECT_STREQ(buf, "abc");
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_HasWord) {
+  // Find flags at beginning, middle and end.
+  EXPECT_TRUE(
+      CpuFeatures_StringView_HasWord(str("first middle last"), "first"));
+  EXPECT_TRUE(
+      CpuFeatures_StringView_HasWord(str("first middle last"), "middle"));
+  EXPECT_TRUE(CpuFeatures_StringView_HasWord(str("first middle last"), "last"));
+  // Do not match partial flags
+  EXPECT_FALSE(
+      CpuFeatures_StringView_HasWord(str("first middle last"), "irst"));
+  EXPECT_FALSE(CpuFeatures_StringView_HasWord(str("first middle last"), "mid"));
+  EXPECT_FALSE(CpuFeatures_StringView_HasWord(str("first middle last"), "las"));
+}
+
+TEST(StringViewTest, CpuFeatures_StringView_GetAttributeKeyValue) {
+  const StringView line = str(" key :   first middle last   ");
+  StringView key, value;
+  EXPECT_TRUE(CpuFeatures_StringView_GetAttributeKeyValue(line, &key, &value));
+  EXPECT_EQ(key, str("key"));
+  EXPECT_EQ(value, str("first middle last"));
+}
+
+TEST(StringViewTest, FailingGetAttributeKeyValue) {
+  const StringView line = str("key  first middle last");
+  StringView key, value;
+  EXPECT_FALSE(CpuFeatures_StringView_GetAttributeKeyValue(line, &key, &value));
+}
+
+}  // namespace
+}  // namespace cpu_features