cronet: temporarily add cpufeatures

We cannot use the prebuilt/ndk "cpufeatures" target because it does not
set a min_sdk_version. An alternative would be to use
//external/cpu_features directly, but it doesn't currently offer a Soong
target for its ndk_compat files. We might want to add one or continue
importing cpufeatures via Chromium.

Test: none
Change-Id: I94fef9842885de377a28e1b969ad5f9dd91f2703

3 files changed, 1647 insertions, 0 deletions

diff --git a/third_party/android_ndk/sources/android/cpufeatures/NOTICE b/third_party/android_ndk/sources/android/cpufeatures/NOTICE
new file mode 100644
index 000000000..d6c092292
--- /dev/null
+++ b/third_party/android_ndk/sources/android/cpufeatures/NOTICE
@@ -0,0 +1,13 @@
+Copyright (C) 2016 The Android Open Source Project
+
+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.
diff --git a/third_party/android_ndk/sources/android/cpufeatures/cpu-features.c b/third_party/android_ndk/sources/android/cpufeatures/cpu-features.c
new file mode 100644
index 000000000..6dae30c21
--- /dev/null
+++ b/third_party/android_ndk/sources/android/cpufeatures/cpu-features.c
@@ -0,0 +1,1313 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* ChangeLog for this library:
+ *
+ * NDK r10e?: Add MIPS MSA feature.
+ *
+ * NDK r10: Support for 64-bit CPUs (Intel, ARM & MIPS).
+ *
+ * NDK r8d: Add android_setCpu().
+ *
+ * NDK r8c: Add new ARM CPU features: VFPv2, VFP_D32, VFP_FP16,
+ *          VFP_FMA, NEON_FMA, IDIV_ARM, IDIV_THUMB2 and iWMMXt.
+ *
+ *          Rewrite the code to parse /proc/self/auxv instead of
+ *          the "Features" field in /proc/cpuinfo.
+ *
+ *          Dynamically allocate the buffer that hold the content
+ *          of /proc/cpuinfo to deal with newer hardware.
+ *
+ * NDK r7c: Fix CPU count computation. The old method only reported the
+ *           number of _active_ CPUs when the library was initialized,
+ *           which could be less than the real total.
+ *
+ * NDK r5: Handle buggy kernels which report a CPU Architecture number of 7
+ *         for an ARMv6 CPU (see below).
+ *
+ *         Handle kernels that only report 'neon', and not 'vfpv3'
+ *         (VFPv3 is mandated by the ARM architecture is Neon is implemented)
+ *
+ *         Handle kernels that only report 'vfpv3d16', and not 'vfpv3'
+ *
+ *         Fix x86 compilation. Report ANDROID_CPU_FAMILY_X86 in
+ *         android_getCpuFamily().
+ *
+ * NDK r4: Initial release
+ */
+
+#include "cpu-features.h"
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/system_properties.h>
+#include <unistd.h>
+
+static  pthread_once_t     g_once;
+static  int                g_inited;
+static  AndroidCpuFamily   g_cpuFamily;
+static  uint64_t           g_cpuFeatures;
+static  int                g_cpuCount;
+
+#ifdef __arm__
+static  uint32_t           g_cpuIdArm;
+#endif
+
+static const int android_cpufeatures_debug = 0;
+
+#define  D(...) \
+    do { \
+        if (android_cpufeatures_debug) { \
+            printf(__VA_ARGS__); fflush(stdout); \
+        } \
+    } while (0)
+
+#ifdef __i386__
+static __inline__ void x86_cpuid(int func, int values[4])
+{
+    int a, b, c, d;
+    /* We need to preserve ebx since we're compiling PIC code */
+    /* this means we can't use "=b" for the second output register */
+    __asm__ __volatile__ ( \
+      "push %%ebx\n"
+      "cpuid\n" \
+      "mov %%ebx, %1\n"
+      "pop %%ebx\n"
+      : "=a" (a), "=r" (b), "=c" (c), "=d" (d) \
+      : "a" (func) \
+    );
+    values[0] = a;
+    values[1] = b;
+    values[2] = c;
+    values[3] = d;
+}
+#elif defined(__x86_64__)
+static __inline__ void x86_cpuid(int func, int values[4])
+{
+    int64_t a, b, c, d;
+    /* We need to preserve ebx since we're compiling PIC code */
+    /* this means we can't use "=b" for the second output register */
+    __asm__ __volatile__ ( \
+      "push %%rbx\n"
+      "cpuid\n" \
+      "mov %%rbx, %1\n"
+      "pop %%rbx\n"
+      : "=a" (a), "=r" (b), "=c" (c), "=d" (d) \
+      : "a" (func) \
+    );
+    values[0] = a;
+    values[1] = b;
+    values[2] = c;
+    values[3] = d;
+}
+#endif
+
+/* Get the size of a file by reading it until the end. This is needed
+ * because files under /proc do not always return a valid size when
+ * using fseek(0, SEEK_END) + ftell(). Nor can they be mmap()-ed.
+ */
+static int
+get_file_size(const char* pathname)
+{
+
+   int fd, result = 0;
+    char buffer[256];
+
+    fd = open(pathname, O_RDONLY);
+    if (fd < 0) {
+        D("Can't open %s: %s\n", pathname, strerror(errno));
+        return -1;
+    }
+
+    for (;;) {
+        int ret = read(fd, buffer, sizeof buffer);
+        if (ret < 0) {
+            if (errno == EINTR)
+                continue;
+            D("Error while reading %s: %s\n", pathname, strerror(errno));
+            break;
+        }
+        if (ret == 0)
+            break;
+
+        result += ret;
+    }
+    close(fd);
+    return result;
+}
+
+/* Read the content of /proc/cpuinfo into a user-provided buffer.
+ * Return the length of the data, or -1 on error. Does *not*
+ * zero-terminate the content. Will not read more
+ * than 'buffsize' bytes.
+ */
+static int
+read_file(const char*  pathname, char*  buffer, size_t  buffsize)
+{
+    int  fd, count;
+
+    fd = open(pathname, O_RDONLY);
+    if (fd < 0) {
+        D("Could not open %s: %s\n", pathname, strerror(errno));
+        return -1;
+    }
+    count = 0;
+    while (count < (int)buffsize) {
+        int ret = read(fd, buffer + count, buffsize - count);
+        if (ret < 0) {
+            if (errno == EINTR)
+                continue;
+            D("Error while reading from %s: %s\n", pathname, strerror(errno));
+            if (count == 0)
+                count = -1;
+            break;
+        }
+        if (ret == 0)
+            break;
+        count += ret;
+    }
+    close(fd);
+    return count;
+}
+
+#ifdef __arm__
+/* Extract the content of a the first occurence of a given field in
+ * the content of /proc/cpuinfo and return it as a heap-allocated
+ * string that must be freed by the caller.
+ *
+ * Return NULL if not found
+ */
+static char*
+extract_cpuinfo_field(const char* buffer, int buflen, const char* field)
+{
+    int  fieldlen = strlen(field);
+    const char* bufend = buffer + buflen;
+    char* result = NULL;
+    int len;
+    const char *p, *q;
+
+    /* Look for first field occurence, and ensures it starts the line. */
+    p = buffer;
+    for (;;) {
+        p = memmem(p, bufend-p, field, fieldlen);
+        if (p == NULL)
+            goto EXIT;
+
+        if (p == buffer || p[-1] == '\n')
+            break;
+
+        p += fieldlen;
+    }
+
+    /* Skip to the first column followed by a space */
+    p += fieldlen;
+    p  = memchr(p, ':', bufend-p);
+    if (p == NULL || p[1] != ' ')
+        goto EXIT;
+
+    /* Find the end of the line */
+    p += 2;
+    q = memchr(p, '\n', bufend-p);
+    if (q == NULL)
+        q = bufend;
+
+    /* Copy the line into a heap-allocated buffer */
+    len = q-p;
+    result = malloc(len+1);
+    if (result == NULL)
+        goto EXIT;
+
+    memcpy(result, p, len);
+    result[len] = '\0';
+
+EXIT:
+    return result;
+}
+
+/* Checks that a space-separated list of items contains one given 'item'.
+ * Returns 1 if found, 0 otherwise.
+ */
+static int
+has_list_item(const char* list, const char* item)
+{
+    const char*  p = list;
+    int itemlen = strlen(item);
+
+    if (list == NULL)
+        return 0;
+
+    while (*p) {
+        const char*  q;
+
+        /* skip spaces */
+        while (*p == ' ' || *p == '\t')
+            p++;
+
+        /* find end of current list item */
+        q = p;
+        while (*q && *q != ' ' && *q != '\t')
+            q++;
+
+        if (itemlen == q-p && !memcmp(p, item, itemlen))
+            return 1;
+
+        /* skip to next item */
+        p = q;
+    }
+    return 0;
+}
+#endif /* __arm__ */
+
+/* Parse a number starting from 'input', but not going further
+ * than 'limit'. Return the value into '*result'.
+ *
+ * NOTE: Does not skip over leading spaces, or deal with sign characters.
+ * NOTE: Ignores overflows.
+ *
+ * The function returns NULL in case of error (bad format), or the new
+ * position after the decimal number in case of success (which will always
+ * be <= 'limit').
+ */
+static const char*
+parse_number(const char* input, const char* limit, int base, int* result)
+{
+    const char* p = input;
+    int val = 0;
+    while (p < limit) {
+        int d = (*p - '0');
+        if ((unsigned)d >= 10U) {
+            d = (*p - 'a');
+            if ((unsigned)d >= 6U)
+              d = (*p - 'A');
+            if ((unsigned)d >= 6U)
+              break;
+            d += 10;
+        }
+        if (d >= base)
+          break;
+        val = val*base + d;
+        p++;
+    }
+    if (p == input)
+        return NULL;
+
+    *result = val;
+    return p;
+}
+
+static const char*
+parse_decimal(const char* input, const char* limit, int* result)
+{
+    return parse_number(input, limit, 10, result);
+}
+
+#ifdef __arm__
+static const char*
+parse_hexadecimal(const char* input, const char* limit, int* result)
+{
+    return parse_number(input, limit, 16, result);
+}
+#endif /* __arm__ */
+
+/* This small data type is used to represent a CPU list / mask, as read
+ * from sysfs on Linux. See http://www.kernel.org/doc/Documentation/cputopology.txt
+ *
+ * For now, we don't expect more than 32 cores on mobile devices, so keep
+ * everything simple.
+ */
+typedef struct {
+    uint32_t mask;
+} CpuList;
+
+static __inline__ void
+cpulist_init(CpuList* list) {
+    list->mask = 0;
+}
+
+static __inline__ void
+cpulist_and(CpuList* list1, CpuList* list2) {
+    list1->mask &= list2->mask;
+}
+
+static __inline__ void
+cpulist_set(CpuList* list, int index) {
+    if ((unsigned)index < 32) {
+        list->mask |= (uint32_t)(1U << index);
+    }
+}
+
+static __inline__ int
+cpulist_count(CpuList* list) {
+    return __builtin_popcount(list->mask);
+}
+
+/* Parse a textual list of cpus and store the result inside a CpuList object.
+ * Input format is the following:
+ * - comma-separated list of items (no spaces)
+ * - each item is either a single decimal number (cpu index), or a range made
+ *   of two numbers separated by a single dash (-). Ranges are inclusive.
+ *
+ * Examples:   0
+ *             2,4-127,128-143
+ *             0-1
+ */
+static void
+cpulist_parse(CpuList* list, const char* line, int line_len)
+{
+    const char* p = line;
+    const char* end = p + line_len;
+    const char* q;
+
+    /* NOTE: the input line coming from sysfs typically contains a
+     * trailing newline, so take care of it in the code below
+     */
+    while (p < end && *p != '\n')
+    {
+        int val, start_value, end_value;
+
+        /* Find the end of current item, and put it into 'q' */
+        q = memchr(p, ',', end-p);
+        if (q == NULL) {
+            q = end;
+        }
+
+        /* Get first value */
+        p = parse_decimal(p, q, &start_value);
+        if (p == NULL)
+            goto BAD_FORMAT;
+
+        end_value = start_value;
+
+        /* If we're not at the end of the item, expect a dash and
+         * and integer; extract end value.
+         */
+        if (p < q && *p == '-') {
+            p = parse_decimal(p+1, q, &end_value);
+            if (p == NULL)
+                goto BAD_FORMAT;
+        }
+
+        /* Set bits CPU list bits */
+        for (val = start_value; val <= end_value; val++) {
+            cpulist_set(list, val);
+        }
+
+        /* Jump to next item */
+        p = q;
+        if (p < end)
+            p++;
+    }
+
+BAD_FORMAT:
+    ;
+}
+
+/* Read a CPU list from one sysfs file */
+static void
+cpulist_read_from(CpuList* list, const char* filename)
+{
+    char   file[64];
+    int    filelen;
+
+    cpulist_init(list);
+
+    filelen = read_file(filename, file, sizeof file);
+    if (filelen < 0) {
+        D("Could not read %s: %s\n", filename, strerror(errno));
+        return;
+    }
+
+    cpulist_parse(list, file, filelen);
+}
+#if defined(__aarch64__)
+// see <uapi/asm/hwcap.h> kernel header
+#define HWCAP_FP                (1 << 0)
+#define HWCAP_ASIMD             (1 << 1)
+#define HWCAP_AES               (1 << 3)
+#define HWCAP_PMULL             (1 << 4)
+#define HWCAP_SHA1              (1 << 5)
+#define HWCAP_SHA2              (1 << 6)
+#define HWCAP_CRC32             (1 << 7)
+#endif
+
+#if defined(__arm__)
+
+// See <asm/hwcap.h> kernel header.
+#define HWCAP_VFP       (1 << 6)
+#define HWCAP_IWMMXT    (1 << 9)
+#define HWCAP_NEON      (1 << 12)
+#define HWCAP_VFPv3     (1 << 13)
+#define HWCAP_VFPv3D16  (1 << 14)
+#define HWCAP_VFPv4     (1 << 16)
+#define HWCAP_IDIVA     (1 << 17)
+#define HWCAP_IDIVT     (1 << 18)
+
+// see <uapi/asm/hwcap.h> kernel header
+#define HWCAP2_AES     (1 << 0)
+#define HWCAP2_PMULL   (1 << 1)
+#define HWCAP2_SHA1    (1 << 2)
+#define HWCAP2_SHA2    (1 << 3)
+#define HWCAP2_CRC32   (1 << 4)
+
+// This is the list of 32-bit ARMv7 optional features that are _always_
+// supported by ARMv8 CPUs, as mandated by the ARM Architecture Reference
+// Manual.
+#define HWCAP_SET_FOR_ARMV8  \
+  ( HWCAP_VFP | \
+    HWCAP_NEON | \
+    HWCAP_VFPv3 | \
+    HWCAP_VFPv4 | \
+    HWCAP_IDIVA | \
+    HWCAP_IDIVT )
+#endif
+
+#if defined(__mips__)
+// see <uapi/asm/hwcap.h> kernel header
+#define HWCAP_MIPS_R6           (1 << 0)
+#define HWCAP_MIPS_MSA          (1 << 1)
+#endif
+
+#if defined(__arm__) || defined(__aarch64__) || defined(__mips__)
+
+#define AT_HWCAP 16
+#define AT_HWCAP2 26
+
+// 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.
+static uint32_t
+get_elf_hwcap_from_getauxval(int hwcap_type) {
+    typedef unsigned long getauxval_func_t(unsigned long);
+
+    dlerror();
+    void* libc_handle = dlopen("libc.so", RTLD_NOW);
+    if (!libc_handle) {
+        D("Could not dlopen() C library: %s\n", dlerror());
+        return 0;
+    }
+
+    uint32_t ret = 0;
+    getauxval_func_t* 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
+
+#if defined(__arm__)
+// Parse /proc/self/auxv to extract the ELF HW capabilities bitmap for the
+// current CPU. Note that this file is not accessible from regular
+// application processes on some Android platform releases.
+// On success, return new ELF hwcaps, or 0 on failure.
+static uint32_t
+get_elf_hwcap_from_proc_self_auxv(void) {
+    const char filepath[] = "/proc/self/auxv";
+    int fd = TEMP_FAILURE_RETRY(open(filepath, O_RDONLY));
+    if (fd < 0) {
+        D("Could not open %s: %s\n", filepath, strerror(errno));
+        return 0;
+    }
+
+    struct { uint32_t tag; uint32_t value; } entry;
+
+    uint32_t result = 0;
+    for (;;) {
+        int ret = TEMP_FAILURE_RETRY(read(fd, (char*)&entry, sizeof entry));
+        if (ret < 0) {
+            D("Error while reading %s: %s\n", filepath, strerror(errno));
+            break;
+        }
+        // Detect end of list.
+        if (ret == 0 || (entry.tag == 0 && entry.value == 0))
+          break;
+        if (entry.tag == AT_HWCAP) {
+          result = entry.value;
+          break;
+        }
+    }
+    close(fd);
+    return result;
+}
+
+/* Compute the ELF HWCAP flags from the content of /proc/cpuinfo.
+ * This works by parsing the 'Features' line, which lists which optional
+ * features the device's CPU supports, on top of its reference
+ * architecture.
+ */
+static uint32_t
+get_elf_hwcap_from_proc_cpuinfo(const char* cpuinfo, int cpuinfo_len) {
+    uint32_t hwcaps = 0;
+    long architecture = 0;
+    char* cpuArch = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "CPU architecture");
+    if (cpuArch) {
+        architecture = strtol(cpuArch, NULL, 10);
+        free(cpuArch);
+
+        if (architecture >= 8L) {
+            // This is a 32-bit ARM binary running on a 64-bit ARM64 kernel.
+            // The 'Features' line only lists the optional features that the
+            // device's CPU supports, compared to its reference architecture
+            // which are of no use for this process.
+            D("Faking 32-bit ARM HWCaps on ARMv%ld CPU\n", architecture);
+            return HWCAP_SET_FOR_ARMV8;
+        }
+    }
+
+    char* cpuFeatures = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "Features");
+    if (cpuFeatures != NULL) {
+        D("Found cpuFeatures = '%s'\n", cpuFeatures);
+
+        if (has_list_item(cpuFeatures, "vfp"))
+            hwcaps |= HWCAP_VFP;
+        if (has_list_item(cpuFeatures, "vfpv3"))
+            hwcaps |= HWCAP_VFPv3;
+        if (has_list_item(cpuFeatures, "vfpv3d16"))
+            hwcaps |= HWCAP_VFPv3D16;
+        if (has_list_item(cpuFeatures, "vfpv4"))
+            hwcaps |= HWCAP_VFPv4;
+        if (has_list_item(cpuFeatures, "neon"))
+            hwcaps |= HWCAP_NEON;
+        if (has_list_item(cpuFeatures, "idiva"))
+            hwcaps |= HWCAP_IDIVA;
+        if (has_list_item(cpuFeatures, "idivt"))
+            hwcaps |= HWCAP_IDIVT;
+        if (has_list_item(cpuFeatures, "idiv"))
+            hwcaps |= HWCAP_IDIVA | HWCAP_IDIVT;
+        if (has_list_item(cpuFeatures, "iwmmxt"))
+            hwcaps |= HWCAP_IWMMXT;
+
+        free(cpuFeatures);
+    }
+    return hwcaps;
+}
+#endif  /* __arm__ */
+
+/* Return the number of cpus present on a given device.
+ *
+ * To handle all weird kernel configurations, we need to compute the
+ * intersection of the 'present' and 'possible' CPU lists and count
+ * the result.
+ */
+static int
+get_cpu_count(void)
+{
+    CpuList cpus_present[1];
+    CpuList cpus_possible[1];
+
+    cpulist_read_from(cpus_present, "/sys/devices/system/cpu/present");
+    cpulist_read_from(cpus_possible, "/sys/devices/system/cpu/possible");
+
+    /* Compute the intersection of both sets to get the actual number of
+     * CPU cores that can be used on this device by the kernel.
+     */
+    cpulist_and(cpus_present, cpus_possible);
+
+    return cpulist_count(cpus_present);
+}
+
+static void
+android_cpuInitFamily(void)
+{
+#if defined(__arm__)
+    g_cpuFamily = ANDROID_CPU_FAMILY_ARM;
+#elif defined(__i386__)
+    g_cpuFamily = ANDROID_CPU_FAMILY_X86;
+#elif defined(__mips64)
+/* Needs to be before __mips__ since the compiler defines both */
+    g_cpuFamily = ANDROID_CPU_FAMILY_MIPS64;
+#elif defined(__mips__)
+    g_cpuFamily = ANDROID_CPU_FAMILY_MIPS;
+#elif defined(__aarch64__)
+    g_cpuFamily = ANDROID_CPU_FAMILY_ARM64;
+#elif defined(__x86_64__)
+    g_cpuFamily = ANDROID_CPU_FAMILY_X86_64;
+#else
+    g_cpuFamily = ANDROID_CPU_FAMILY_UNKNOWN;
+#endif
+}
+
+static void
+android_cpuInit(void)
+{
+    char* cpuinfo = NULL;
+    int   cpuinfo_len;
+
+    android_cpuInitFamily();
+
+    g_cpuFeatures = 0;
+    g_cpuCount    = 1;
+    g_inited      = 1;
+
+    cpuinfo_len = get_file_size("/proc/cpuinfo");
+    if (cpuinfo_len < 0) {
+      D("cpuinfo_len cannot be computed!");
+      return;
+    }
+    cpuinfo = malloc(cpuinfo_len);
+    if (cpuinfo == NULL) {
+      D("cpuinfo buffer could not be allocated");
+      return;
+    }
+    cpuinfo_len = read_file("/proc/cpuinfo", cpuinfo, cpuinfo_len);
+    D("cpuinfo_len is (%d):\n%.*s\n", cpuinfo_len,
+      cpuinfo_len >= 0 ? cpuinfo_len : 0, cpuinfo);
+
+    if (cpuinfo_len < 0)  /* should not happen */ {
+        free(cpuinfo);
+        return;
+    }
+
+    /* Count the CPU cores, the value may be 0 for single-core CPUs */
+    g_cpuCount = get_cpu_count();
+    if (g_cpuCount == 0) {
+        g_cpuCount = 1;
+    }
+
+    D("found cpuCount = %d\n", g_cpuCount);
+
+#ifdef __arm__
+    {
+        /* Extract architecture from the "CPU Architecture" field.
+         * The list is well-known, unlike the the output of
+         * the 'Processor' field which can vary greatly.
+         *
+         * See the definition of the 'proc_arch' array in
+         * $KERNEL/arch/arm/kernel/setup.c and the 'c_show' function in
+         * same file.
+         */
+        char* cpuArch = extract_cpuinfo_field(cpuinfo, cpuinfo_len, "CPU architecture");
+
+        if (cpuArch != NULL) {
+            char*  end;
+            long   archNumber;
+            int    hasARMv7 = 0;
+
+            D("found cpuArch = '%s'\n", cpuArch);
+
+            /* read the initial decimal number, ignore the rest */
+            archNumber = strtol(cpuArch, &end, 10);
+
+            /* Note that ARMv8 is upwards compatible with ARMv7. */
+            if (end > cpuArch && archNumber >= 7) {
+                hasARMv7 = 1;
+            }
+
+            /* Unfortunately, it seems that certain ARMv6-based CPUs
+             * report an incorrect architecture number of 7!
+             *
+             * See http://code.google.com/p/android/issues/detail?id=10812
+             *
+             * We try to correct this by looking at the 'elf_format'
+             * field reported by the 'Processor' field, which is of the
+             * form of "(v7l)" for an ARMv7-based CPU, and "(v6l)" for
+             * an ARMv6-one.
+             */
+            if (hasARMv7) {
+                char* cpuProc = extract_cpuinfo_field(cpuinfo, cpuinfo_len,
+                                                      "Processor");
+                if (cpuProc != NULL) {
+                    D("found cpuProc = '%s'\n", cpuProc);
+                    if (has_list_item(cpuProc, "(v6l)")) {
+                        D("CPU processor and architecture mismatch!!\n");
+                        hasARMv7 = 0;
+                    }
+                    free(cpuProc);
+                }
+            }
+
+            if (hasARMv7) {
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_ARMv7;
+            }
+
+            /* The LDREX / STREX instructions are available from ARMv6 */
+            if (archNumber >= 6) {
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_LDREX_STREX;
+            }
+
+            free(cpuArch);
+        }
+
+        /* Extract the list of CPU features from ELF hwcaps */
+        uint32_t hwcaps = 0;
+        hwcaps = get_elf_hwcap_from_getauxval(AT_HWCAP);
+        if (!hwcaps) {
+            D("Parsing /proc/self/auxv to extract ELF hwcaps!\n");
+            hwcaps = get_elf_hwcap_from_proc_self_auxv();
+        }
+        if (!hwcaps) {
+            // Parsing /proc/self/auxv will fail from regular application
+            // processes on some Android platform versions, when this happens
+            // parse proc/cpuinfo instead.
+            D("Parsing /proc/cpuinfo to extract ELF hwcaps!\n");
+            hwcaps = get_elf_hwcap_from_proc_cpuinfo(cpuinfo, cpuinfo_len);
+        }
+
+        if (hwcaps != 0) {
+            int has_vfp = (hwcaps & HWCAP_VFP);
+            int has_vfpv3 = (hwcaps & HWCAP_VFPv3);
+            int has_vfpv3d16 = (hwcaps & HWCAP_VFPv3D16);
+            int has_vfpv4 = (hwcaps & HWCAP_VFPv4);
+            int has_neon = (hwcaps & HWCAP_NEON);
+            int has_idiva = (hwcaps & HWCAP_IDIVA);
+            int has_idivt = (hwcaps & HWCAP_IDIVT);
+            int has_iwmmxt = (hwcaps & HWCAP_IWMMXT);
+
+            // The kernel does a poor job at ensuring consistency when
+            // describing CPU features. So lots of guessing is needed.
+
+            // 'vfpv4' implies VFPv3|VFP_FMA|FP16
+            if (has_vfpv4)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3    |
+                                 ANDROID_CPU_ARM_FEATURE_VFP_FP16 |
+                                 ANDROID_CPU_ARM_FEATURE_VFP_FMA;
+
+            // 'vfpv3' or 'vfpv3d16' imply VFPv3. Note that unlike GCC,
+            // a value of 'vfpv3' doesn't necessarily mean that the D32
+            // feature is present, so be conservative. All CPUs in the
+            // field that support D32 also support NEON, so this should
+            // not be a problem in practice.
+            if (has_vfpv3 || has_vfpv3d16)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
+
+            // 'vfp' is super ambiguous. Depending on the kernel, it can
+            // either mean VFPv2 or VFPv3. Make it depend on ARMv7.
+            if (has_vfp) {
+              if (g_cpuFeatures & ANDROID_CPU_ARM_FEATURE_ARMv7)
+                  g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3;
+              else
+                  g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2;
+            }
+
+            // Neon implies VFPv3|D32, and if vfpv4 is detected, NEON_FMA
+            if (has_neon) {
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv3 |
+                                 ANDROID_CPU_ARM_FEATURE_NEON |
+                                 ANDROID_CPU_ARM_FEATURE_VFP_D32;
+              if (has_vfpv4)
+                  g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_NEON_FMA;
+            }
+
+            // VFPv3 implies VFPv2 and ARMv7
+            if (g_cpuFeatures & ANDROID_CPU_ARM_FEATURE_VFPv3)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_VFPv2 |
+                                 ANDROID_CPU_ARM_FEATURE_ARMv7;
+
+            if (has_idiva)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_ARM;
+            if (has_idivt)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2;
+
+            if (has_iwmmxt)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_iWMMXt;
+        }
+
+        /* Extract the list of CPU features from ELF hwcaps2 */
+        uint32_t hwcaps2 = 0;
+        hwcaps2 = get_elf_hwcap_from_getauxval(AT_HWCAP2);
+        if (hwcaps2 != 0) {
+            int has_aes     = (hwcaps2 & HWCAP2_AES);
+            int has_pmull   = (hwcaps2 & HWCAP2_PMULL);
+            int has_sha1    = (hwcaps2 & HWCAP2_SHA1);
+            int has_sha2    = (hwcaps2 & HWCAP2_SHA2);
+            int has_crc32   = (hwcaps2 & HWCAP2_CRC32);
+
+            if (has_aes)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_AES;
+            if (has_pmull)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_PMULL;
+            if (has_sha1)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_SHA1;
+            if (has_sha2)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_SHA2;
+            if (has_crc32)
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_CRC32;
+        }
+        /* Extract the cpuid value from various fields */
+        // The CPUID value is broken up in several entries in /proc/cpuinfo.
+        // This table is used to rebuild it from the entries.
+        static const struct CpuIdEntry {
+            const char* field;
+            char        format;
+            char        bit_lshift;
+            char        bit_length;
+        } cpu_id_entries[] = {
+            { "CPU implementer", 'x', 24, 8 },
+            { "CPU variant", 'x', 20, 4 },
+            { "CPU part", 'x', 4, 12 },
+            { "CPU revision", 'd', 0, 4 },
+        };
+        size_t i;
+        D("Parsing /proc/cpuinfo to recover CPUID\n");
+        for (i = 0;
+             i < sizeof(cpu_id_entries)/sizeof(cpu_id_entries[0]);
+             ++i) {
+            const struct CpuIdEntry* entry = &cpu_id_entries[i];
+            char* value = extract_cpuinfo_field(cpuinfo,
+                                                cpuinfo_len,
+                                                entry->field);
+            if (value == NULL)
+                continue;
+
+            D("field=%s value='%s'\n", entry->field, value);
+            char* value_end = value + strlen(value);
+            int val = 0;
+            const char* start = value;
+            const char* p;
+            if (value[0] == '0' && (value[1] == 'x' || value[1] == 'X')) {
+              start += 2;
+              p = parse_hexadecimal(start, value_end, &val);
+            } else if (entry->format == 'x')
+              p = parse_hexadecimal(value, value_end, &val);
+            else
+              p = parse_decimal(value, value_end, &val);
+
+            if (p > (const char*)start) {
+              val &= ((1 << entry->bit_length)-1);
+              val <<= entry->bit_lshift;
+              g_cpuIdArm |= (uint32_t) val;
+            }
+
+            free(value);
+        }
+
+        // Handle kernel configuration bugs that prevent the correct
+        // reporting of CPU features.
+        static const struct CpuFix {
+            uint32_t  cpuid;
+            uint64_t  or_flags;
+        } cpu_fixes[] = {
+            /* The Nexus 4 (Qualcomm Krait) kernel configuration
+             * forgets to report IDIV support. */
+            { 0x510006f2, ANDROID_CPU_ARM_FEATURE_IDIV_ARM |
+                          ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 },
+            { 0x510006f3, ANDROID_CPU_ARM_FEATURE_IDIV_ARM |
+                          ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 },
+        };
+        size_t n;
+        for (n = 0; n < sizeof(cpu_fixes)/sizeof(cpu_fixes[0]); ++n) {
+            const struct CpuFix* entry = &cpu_fixes[n];
+
+            if (g_cpuIdArm == entry->cpuid)
+                g_cpuFeatures |= entry->or_flags;
+        }
+
+        // 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.
+        char* hardware = extract_cpuinfo_field(cpuinfo,
+                                               cpuinfo_len,
+                                               "Hardware");
+        if (hardware) {
+            if (!strcmp(hardware, "Goldfish") &&
+                g_cpuIdArm == 0x4100c080 &&
+                (g_cpuFamily & ANDROID_CPU_ARM_FEATURE_ARMv7) != 0) {
+                g_cpuFeatures |= ANDROID_CPU_ARM_FEATURE_IDIV_ARM;
+            }
+            free(hardware);
+        }
+    }
+#endif /* __arm__ */
+#ifdef __aarch64__
+    {
+        /* Extract the list of CPU features from ELF hwcaps */
+        uint32_t hwcaps = 0;
+        hwcaps = get_elf_hwcap_from_getauxval(AT_HWCAP);
+        if (hwcaps != 0) {
+            int has_fp      = (hwcaps & HWCAP_FP);
+            int has_asimd   = (hwcaps & HWCAP_ASIMD);
+            int has_aes     = (hwcaps & HWCAP_AES);
+            int has_pmull   = (hwcaps & HWCAP_PMULL);
+            int has_sha1    = (hwcaps & HWCAP_SHA1);
+            int has_sha2    = (hwcaps & HWCAP_SHA2);
+            int has_crc32   = (hwcaps & HWCAP_CRC32);
+
+            if(has_fp == 0) {
+                D("ERROR: Floating-point unit missing, but is required by Android on AArch64 CPUs\n");
+            }
+            if(has_asimd == 0) {
+                D("ERROR: ASIMD unit missing, but is required by Android on AArch64 CPUs\n");
+            }
+
+            if (has_fp)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_FP;
+            if (has_asimd)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_ASIMD;
+            if (has_aes)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_AES;
+            if (has_pmull)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_PMULL;
+            if (has_sha1)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_SHA1;
+            if (has_sha2)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_SHA2;
+            if (has_crc32)
+                g_cpuFeatures |= ANDROID_CPU_ARM64_FEATURE_CRC32;
+        }
+    }
+#endif /* __aarch64__ */
+
+#if defined(__i386__) || defined(__x86_64__)
+    int regs[4];
+
+/* According to http://en.wikipedia.org/wiki/CPUID */
+#define VENDOR_INTEL_b  0x756e6547
+#define VENDOR_INTEL_c  0x6c65746e
+#define VENDOR_INTEL_d  0x49656e69
+
+    x86_cpuid(0, regs);
+    int vendorIsIntel = (regs[1] == VENDOR_INTEL_b &&
+                         regs[2] == VENDOR_INTEL_c &&
+                         regs[3] == VENDOR_INTEL_d);
+
+    x86_cpuid(1, regs);
+    if ((regs[2] & (1 << 9)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSSE3;
+    }
+    if ((regs[2] & (1 << 23)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_POPCNT;
+    }
+    if ((regs[2] & (1 << 19)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSE4_1;
+    }
+    if ((regs[2] & (1 << 20)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SSE4_2;
+    }
+    if (vendorIsIntel && (regs[2] & (1 << 22)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_MOVBE;
+    }
+    if ((regs[2] & (1 << 25)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_AES_NI;
+    }
+    if ((regs[2] & (1 << 28)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_AVX;
+    }
+    if ((regs[2] & (1 << 30)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_RDRAND;
+    }
+
+    x86_cpuid(7, regs);
+    if ((regs[1] & (1 << 5)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_AVX2;
+    }
+    if ((regs[1] & (1 << 29)) != 0) {
+        g_cpuFeatures |= ANDROID_CPU_X86_FEATURE_SHA_NI;
+    }
+
+
+#endif
+#if defined( __mips__)
+    {   /* MIPS and MIPS64 */
+        /* Extract the list of CPU features from ELF hwcaps */
+        uint32_t hwcaps = 0;
+        hwcaps = get_elf_hwcap_from_getauxval(AT_HWCAP);
+        if (hwcaps != 0) {
+            int has_r6      = (hwcaps & HWCAP_MIPS_R6);
+            int has_msa     = (hwcaps & HWCAP_MIPS_MSA);
+            if (has_r6)
+                g_cpuFeatures |= ANDROID_CPU_MIPS_FEATURE_R6;
+            if (has_msa)
+                g_cpuFeatures |= ANDROID_CPU_MIPS_FEATURE_MSA;
+        }
+    }
+#endif /* __mips__ */
+
+    free(cpuinfo);
+}
+
+
+AndroidCpuFamily
+android_getCpuFamily(void)
+{
+    pthread_once(&g_once, android_cpuInit);
+    return g_cpuFamily;
+}
+
+
+uint64_t
+android_getCpuFeatures(void)
+{
+    pthread_once(&g_once, android_cpuInit);
+    return g_cpuFeatures;
+}
+
+
+int
+android_getCpuCount(void)
+{
+    pthread_once(&g_once, android_cpuInit);
+    return g_cpuCount;
+}
+
+static void
+android_cpuInitTrivial(void)
+{
+    g_inited = 1;
+}
+
+int
+android_setCpu(int cpu_count, uint64_t cpu_features)
+{
+    /* Fail if the library was already initialized. */
+    if (g_inited)
+        return 0;
+
+    android_cpuInitFamily();
+    g_cpuCount = (cpu_count <= 0 ? 1 : cpu_count);
+    g_cpuFeatures = cpu_features;
+    pthread_once(&g_once, android_cpuInitTrivial);
+
+    return 1;
+}
+
+#ifdef __arm__
+uint32_t
+android_getCpuIdArm(void)
+{
+    pthread_once(&g_once, android_cpuInit);
+    return g_cpuIdArm;
+}
+
+int
+android_setCpuArm(int cpu_count, uint64_t cpu_features, uint32_t cpu_id)
+{
+    if (!android_setCpu(cpu_count, cpu_features))
+        return 0;
+
+    g_cpuIdArm = cpu_id;
+    return 1;
+}
+#endif  /* __arm__ */
+
+/*
+ * Technical note: Making sense of ARM's FPU architecture versions.
+ *
+ * FPA was ARM's first attempt at an FPU architecture. There is no Android
+ * device that actually uses it since this technology was already obsolete
+ * when the project started. If you see references to FPA instructions
+ * somewhere, you can be sure that this doesn't apply to Android at all.
+ *
+ * FPA was followed by "VFP", soon renamed "VFPv1" due to the emergence of
+ * new versions / additions to it. ARM considers this obsolete right now,
+ * and no known Android device implements it either.
+ *
+ * VFPv2 added a few instructions to VFPv1, and is an *optional* extension
+ * supported by some ARMv5TE, ARMv6 and ARMv6T2 CPUs. Note that a device
+ * supporting the 'armeabi' ABI doesn't necessarily support these.
+ *
+ * VFPv3-D16 adds a few instructions on top of VFPv2 and is typically used
+ * on ARMv7-A CPUs which implement a FPU. Note that it is also mandated
+ * by the Android 'armeabi-v7a' ABI. The -D16 suffix in its name means
+ * that it provides 16 double-precision FPU registers (d0-d15) and 32
+ * single-precision ones (s0-s31) which happen to be mapped to the same
+ * register banks.
+ *
+ * VFPv3-D32 is the name of an extension to VFPv3-D16 that provides 16
+ * additional double precision registers (d16-d31). Note that there are
+ * still only 32 single precision registers.
+ *
+ * VFPv3xD is a *subset* of VFPv3-D16 that only provides single-precision
+ * registers. It is only used on ARMv7-M (i.e. on micro-controllers) which
+ * are not supported by Android. Note that it is not compatible with VFPv2.
+ *
+ * NOTE: The term 'VFPv3' usually designate either VFPv3-D16 or VFPv3-D32
+ *       depending on context. For example GCC uses it for VFPv3-D32, but
+ *       the Linux kernel code uses it for VFPv3-D16 (especially in
+ *       /proc/cpuinfo). Always try to use the full designation when
+ *       possible.
+ *
+ * NEON, a.k.a. "ARM Advanced SIMD" is an extension that provides
+ * instructions to perform parallel computations on vectors of 8, 16,
+ * 32, 64 and 128 bit quantities. NEON requires VFPv32-D32 since all
+ * NEON registers are also mapped to the same register banks.
+ *
+ * VFPv4-D16, adds a few instructions on top of VFPv3-D16 in order to
+ * perform fused multiply-accumulate on VFP registers, as well as
+ * half-precision (16-bit) conversion operations.
+ *
+ * VFPv4-D32 is VFPv4-D16 with 32, instead of 16, FPU double precision
+ * registers.
+ *
+ * VPFv4-NEON is VFPv4-D32 with NEON instructions. It also adds fused
+ * multiply-accumulate instructions that work on the NEON registers.
+ *
+ * NOTE: Similarly, "VFPv4" might either reference VFPv4-D16 or VFPv4-D32
+ *       depending on context.
+ *
+ * The following information was determined by scanning the binutils-2.22
+ * sources:
+ *
+ * Basic VFP instruction subsets:
+ *
+ * #define FPU_VFP_EXT_V1xD 0x08000000     // Base VFP instruction set.
+ * #define FPU_VFP_EXT_V1   0x04000000     // Double-precision insns.
+ * #define FPU_VFP_EXT_V2   0x02000000     // ARM10E VFPr1.
+ * #define FPU_VFP_EXT_V3xD 0x01000000     // VFPv3 single-precision.
+ * #define FPU_VFP_EXT_V3   0x00800000     // VFPv3 double-precision.
+ * #define FPU_NEON_EXT_V1  0x00400000     // Neon (SIMD) insns.
+ * #define FPU_VFP_EXT_D32  0x00200000     // Registers D16-D31.
+ * #define FPU_VFP_EXT_FP16 0x00100000     // Half-precision extensions.
+ * #define FPU_NEON_EXT_FMA 0x00080000     // Neon fused multiply-add
+ * #define FPU_VFP_EXT_FMA  0x00040000     // VFP fused multiply-add
+ *
+ * FPU types (excluding NEON)
+ *
+ * FPU_VFP_V1xD (EXT_V1xD)
+ *    |
+ *    +--------------------------+
+ *    |                          |
+ * FPU_VFP_V1 (+EXT_V1)       FPU_VFP_V3xD (+EXT_V2+EXT_V3xD)
+ *    |                          |
+ *    |                          |
+ * FPU_VFP_V2 (+EXT_V2)       FPU_VFP_V4_SP_D16 (+EXT_FP16+EXT_FMA)
+ *    |
+ * FPU_VFP_V3D16 (+EXT_Vx3D+EXT_V3)
+ *    |
+ *    +--------------------------+
+ *    |                          |
+ * FPU_VFP_V3 (+EXT_D32)     FPU_VFP_V4D16 (+EXT_FP16+EXT_FMA)
+ *    |                          |
+ *    |                      FPU_VFP_V4 (+EXT_D32)
+ *    |
+ * FPU_VFP_HARD (+EXT_FMA+NEON_EXT_FMA)
+ *
+ * VFP architectures:
+ *
+ * ARCH_VFP_V1xD  (EXT_V1xD)
+ *   |
+ *   +------------------+
+ *   |                  |
+ *   |             ARCH_VFP_V3xD (+EXT_V2+EXT_V3xD)
+ *   |                  |
+ *   |             ARCH_VFP_V3xD_FP16 (+EXT_FP16)
+ *   |                  |
+ *   |             ARCH_VFP_V4_SP_D16 (+EXT_FMA)
+ *   |
+ * ARCH_VFP_V1 (+EXT_V1)
+ *   |
+ * ARCH_VFP_V2 (+EXT_V2)
+ *   |
+ * ARCH_VFP_V3D16 (+EXT_V3xD+EXT_V3)
+ *   |
+ *   +-------------------+
+ *   |                   |
+ *   |         ARCH_VFP_V3D16_FP16  (+EXT_FP16)
+ *   |
+ *   +-------------------+
+ *   |                   |
+ *   |         ARCH_VFP_V4_D16 (+EXT_FP16+EXT_FMA)
+ *   |                   |
+ *   |         ARCH_VFP_V4 (+EXT_D32)
+ *   |                   |
+ *   |         ARCH_NEON_VFP_V4 (+EXT_NEON+EXT_NEON_FMA)
+ *   |
+ * ARCH_VFP_V3 (+EXT_D32)
+ *   |
+ *   +-------------------+
+ *   |                   |
+ *   |         ARCH_VFP_V3_FP16 (+EXT_FP16)
+ *   |
+ * ARCH_VFP_V3_PLUS_NEON_V1 (+EXT_NEON)
+ *   |
+ * ARCH_NEON_FP16 (+EXT_FP16)
+ *
+ * -fpu=<name> values and their correspondance with FPU architectures above:
+ *
+ *   {"vfp",               FPU_ARCH_VFP_V2},
+ *   {"vfp9",              FPU_ARCH_VFP_V2},
+ *   {"vfp3",              FPU_ARCH_VFP_V3}, // For backwards compatbility.
+ *   {"vfp10",             FPU_ARCH_VFP_V2},
+ *   {"vfp10-r0",          FPU_ARCH_VFP_V1},
+ *   {"vfpxd",             FPU_ARCH_VFP_V1xD},
+ *   {"vfpv2",             FPU_ARCH_VFP_V2},
+ *   {"vfpv3",             FPU_ARCH_VFP_V3},
+ *   {"vfpv3-fp16",        FPU_ARCH_VFP_V3_FP16},
+ *   {"vfpv3-d16",         FPU_ARCH_VFP_V3D16},
+ *   {"vfpv3-d16-fp16",    FPU_ARCH_VFP_V3D16_FP16},
+ *   {"vfpv3xd",           FPU_ARCH_VFP_V3xD},
+ *   {"vfpv3xd-fp16",      FPU_ARCH_VFP_V3xD_FP16},
+ *   {"neon",              FPU_ARCH_VFP_V3_PLUS_NEON_V1},
+ *   {"neon-fp16",         FPU_ARCH_NEON_FP16},
+ *   {"vfpv4",             FPU_ARCH_VFP_V4},
+ *   {"vfpv4-d16",         FPU_ARCH_VFP_V4D16},
+ *   {"fpv4-sp-d16",       FPU_ARCH_VFP_V4_SP_D16},
+ *   {"neon-vfpv4",        FPU_ARCH_NEON_VFP_V4},
+ *
+ *
+ * Simplified diagram that only includes FPUs supported by Android:
+ * Only ARCH_VFP_V3D16 is actually mandated by the armeabi-v7a ABI,
+ * all others are optional and must be probed at runtime.
+ *
+ * ARCH_VFP_V3D16 (EXT_V1xD+EXT_V1+EXT_V2+EXT_V3xD+EXT_V3)
+ *   |
+ *   +-------------------+
+ *   |                   |
+ *   |         ARCH_VFP_V3D16_FP16  (+EXT_FP16)
+ *   |
+ *   +-------------------+
+ *   |                   |
+ *   |         ARCH_VFP_V4_D16 (+EXT_FP16+EXT_FMA)
+ *   |                   |
+ *   |         ARCH_VFP_V4 (+EXT_D32)
+ *   |                   |
+ *   |         ARCH_NEON_VFP_V4 (+EXT_NEON+EXT_NEON_FMA)
+ *   |
+ * ARCH_VFP_V3 (+EXT_D32)
+ *   |
+ *   +-------------------+
+ *   |                   |
+ *   |         ARCH_VFP_V3_FP16 (+EXT_FP16)
+ *   |
+ * ARCH_VFP_V3_PLUS_NEON_V1 (+EXT_NEON)
+ *   |
+ * ARCH_NEON_FP16 (+EXT_FP16)
+ *
+ */
diff --git a/third_party/android_ndk/sources/android/cpufeatures/cpu-features.h b/third_party/android_ndk/sources/android/cpufeatures/cpu-features.h
new file mode 100644
index 000000000..d38990886
--- /dev/null
+++ b/third_party/android_ndk/sources/android/cpufeatures/cpu-features.h
@@ -0,0 +1,321 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <sys/cdefs.h>
+#include <stdint.h>
+
+__BEGIN_DECLS
+
+/* A list of valid values returned by android_getCpuFamily().
+ * They describe the CPU Architecture of the current process.
+ */
+typedef enum {
+    ANDROID_CPU_FAMILY_UNKNOWN = 0,
+    ANDROID_CPU_FAMILY_ARM,
+    ANDROID_CPU_FAMILY_X86,
+    ANDROID_CPU_FAMILY_MIPS,
+    ANDROID_CPU_FAMILY_ARM64,
+    ANDROID_CPU_FAMILY_X86_64,
+    ANDROID_CPU_FAMILY_MIPS64,
+
+    ANDROID_CPU_FAMILY_MAX  /* do not remove */
+
+} AndroidCpuFamily;
+
+/* Return the CPU family of the current process.
+ *
+ * Note that this matches the bitness of the current process. I.e. when
+ * running a 32-bit binary on a 64-bit capable CPU, this will return the
+ * 32-bit CPU family value.
+ */
+extern AndroidCpuFamily android_getCpuFamily(void);
+
+/* Return a bitmap describing a set of optional CPU features that are
+ * supported by the current device's CPU. The exact bit-flags returned
+ * depend on the value returned by android_getCpuFamily(). See the
+ * documentation for the ANDROID_CPU_*_FEATURE_* flags below for details.
+ */
+extern uint64_t android_getCpuFeatures(void);
+
+/* The list of feature flags for ANDROID_CPU_FAMILY_ARM that can be
+ * recognized by the library (see note below for 64-bit ARM). Value details
+ * are:
+ *
+ *   VFPv2:
+ *     CPU supports the VFPv2 instruction set. Many, but not all, ARMv6 CPUs
+ *     support these instructions. VFPv2 is a subset of VFPv3 so this will
+ *     be set whenever VFPv3 is set too.
+ *
+ *   ARMv7:
+ *     CPU supports the ARMv7-A basic instruction set.
+ *     This feature is mandated by the 'armeabi-v7a' ABI.
+ *
+ *   VFPv3:
+ *     CPU supports the VFPv3-D16 instruction set, providing hardware FPU
+ *     support for single and double precision floating point registers.
+ *     Note that only 16 FPU registers are available by default, unless
+ *     the D32 bit is set too. This feature is also mandated by the
+ *     'armeabi-v7a' ABI.
+ *
+ *   VFP_D32:
+ *     CPU VFP optional extension that provides 32 FPU registers,
+ *     instead of 16. Note that ARM mandates this feature is the 'NEON'
+ *     feature is implemented by the CPU.
+ *
+ *   NEON:
+ *     CPU FPU supports "ARM Advanced SIMD" instructions, also known as
+ *     NEON. Note that this mandates the VFP_D32 feature as well, per the
+ *     ARM Architecture specification.
+ *
+ *   VFP_FP16:
+ *     Half-width floating precision VFP extension. If set, the CPU
+ *     supports instructions to perform floating-point operations on
+ *     16-bit registers. This is part of the VFPv4 specification, but
+ *     not mandated by any Android ABI.
+ *
+ *   VFP_FMA:
+ *     Fused multiply-accumulate VFP instructions extension. Also part of
+ *     the VFPv4 specification, but not mandated by any Android ABI.
+ *
+ *   NEON_FMA:
+ *     Fused multiply-accumulate NEON instructions extension. Optional
+ *     extension from the VFPv4 specification, but not mandated by any
+ *     Android ABI.
+ *
+ *   IDIV_ARM:
+ *     Integer division available in ARM mode. Only available
+ *     on recent CPUs (e.g. Cortex-A15).
+ *
+ *   IDIV_THUMB2:
+ *     Integer division available in Thumb-2 mode. Only available
+ *     on recent CPUs (e.g. Cortex-A15).
+ *
+ *   iWMMXt:
+ *     Optional extension that adds MMX registers and operations to an
+ *     ARM CPU. This is only available on a few XScale-based CPU designs
+ *     sold by Marvell. Pretty rare in practice.
+ *
+ *   AES:
+ *     CPU supports AES instructions. These instructions are only
+ *     available for 32-bit applications running on ARMv8 CPU.
+ *
+ *   CRC32:
+ *     CPU supports CRC32 instructions. These instructions are only
+ *     available for 32-bit applications running on ARMv8 CPU.
+ *
+ *   SHA2:
+ *     CPU supports SHA2 instructions. These instructions are only
+ *     available for 32-bit applications running on ARMv8 CPU.
+ *
+ *   SHA1:
+ *     CPU supports SHA1 instructions. These instructions are only
+ *     available for 32-bit applications running on ARMv8 CPU.
+ *
+ *   PMULL:
+ *     CPU supports 64-bit PMULL and PMULL2 instructions. These
+ *     instructions are only available for 32-bit applications
+ *     running on ARMv8 CPU.
+ *
+ * If you want to tell the compiler to generate code that targets one of
+ * the feature set above, you should probably use one of the following
+ * flags (for more details, see technical note at the end of this file):
+ *
+ *   -mfpu=vfp
+ *   -mfpu=vfpv2
+ *     These are equivalent and tell GCC to use VFPv2 instructions for
+ *     floating-point operations. Use this if you want your code to
+ *     run on *some* ARMv6 devices, and any ARMv7-A device supported
+ *     by Android.
+ *
+ *     Generated code requires VFPv2 feature.
+ *
+ *   -mfpu=vfpv3-d16
+ *     Tell GCC to use VFPv3 instructions (using only 16 FPU registers).
+ *     This should be generic code that runs on any CPU that supports the
+ *     'armeabi-v7a' Android ABI. Note that no ARMv6 CPU supports this.
+ *
+ *     Generated code requires VFPv3 feature.
+ *
+ *   -mfpu=vfpv3
+ *     Tell GCC to use VFPv3 instructions with 32 FPU registers.
+ *     Generated code requires VFPv3|VFP_D32 features.
+ *
+ *   -mfpu=neon
+ *     Tell GCC to use VFPv3 instructions with 32 FPU registers, and
+ *     also support NEON intrinsics (see <arm_neon.h>).
+ *     Generated code requires VFPv3|VFP_D32|NEON features.
+ *
+ *   -mfpu=vfpv4-d16
+ *     Generated code requires VFPv3|VFP_FP16|VFP_FMA features.
+ *
+ *   -mfpu=vfpv4
+ *     Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32 features.
+ *
+ *   -mfpu=neon-vfpv4
+ *     Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32|NEON|NEON_FMA
+ *     features.
+ *
+ *   -mcpu=cortex-a7
+ *   -mcpu=cortex-a15
+ *     Generated code requires VFPv3|VFP_FP16|VFP_FMA|VFP_D32|
+ *                             NEON|NEON_FMA|IDIV_ARM|IDIV_THUMB2
+ *     This flag implies -mfpu=neon-vfpv4.
+ *
+ *   -mcpu=iwmmxt
+ *     Allows the use of iWMMXt instrinsics with GCC.
+ *
+ * IMPORTANT NOTE: These flags should only be tested when
+ * android_getCpuFamily() returns ANDROID_CPU_FAMILY_ARM, i.e. this is a
+ * 32-bit process.
+ *
+ * When running a 64-bit ARM process on an ARMv8 CPU,
+ * android_getCpuFeatures() will return a different set of bitflags
+ */
+enum {
+    ANDROID_CPU_ARM_FEATURE_ARMv7       = (1 << 0),
+    ANDROID_CPU_ARM_FEATURE_VFPv3       = (1 << 1),
+    ANDROID_CPU_ARM_FEATURE_NEON        = (1 << 2),
+    ANDROID_CPU_ARM_FEATURE_LDREX_STREX = (1 << 3),
+    ANDROID_CPU_ARM_FEATURE_VFPv2       = (1 << 4),
+    ANDROID_CPU_ARM_FEATURE_VFP_D32     = (1 << 5),
+    ANDROID_CPU_ARM_FEATURE_VFP_FP16    = (1 << 6),
+    ANDROID_CPU_ARM_FEATURE_VFP_FMA     = (1 << 7),
+    ANDROID_CPU_ARM_FEATURE_NEON_FMA    = (1 << 8),
+    ANDROID_CPU_ARM_FEATURE_IDIV_ARM    = (1 << 9),
+    ANDROID_CPU_ARM_FEATURE_IDIV_THUMB2 = (1 << 10),
+    ANDROID_CPU_ARM_FEATURE_iWMMXt      = (1 << 11),
+    ANDROID_CPU_ARM_FEATURE_AES         = (1 << 12),
+    ANDROID_CPU_ARM_FEATURE_PMULL       = (1 << 13),
+    ANDROID_CPU_ARM_FEATURE_SHA1        = (1 << 14),
+    ANDROID_CPU_ARM_FEATURE_SHA2        = (1 << 15),
+    ANDROID_CPU_ARM_FEATURE_CRC32       = (1 << 16),
+};
+
+/* The bit flags corresponding to the output of android_getCpuFeatures()
+ * when android_getCpuFamily() returns ANDROID_CPU_FAMILY_ARM64. Value details
+ * are:
+ *
+ *   FP:
+ *     CPU has Floating-point unit.
+ *
+ *   ASIMD:
+ *     CPU has Advanced SIMD unit.
+ *
+ *   AES:
+ *     CPU supports AES instructions.
+ *
+ *   CRC32:
+ *     CPU supports CRC32 instructions.
+ *
+ *   SHA2:
+ *     CPU supports SHA2 instructions.
+ *
+ *   SHA1:
+ *     CPU supports SHA1 instructions.
+ *
+ *   PMULL:
+ *     CPU supports 64-bit PMULL and PMULL2 instructions.
+ */
+enum {
+    ANDROID_CPU_ARM64_FEATURE_FP      = (1 << 0),
+    ANDROID_CPU_ARM64_FEATURE_ASIMD   = (1 << 1),
+    ANDROID_CPU_ARM64_FEATURE_AES     = (1 << 2),
+    ANDROID_CPU_ARM64_FEATURE_PMULL   = (1 << 3),
+    ANDROID_CPU_ARM64_FEATURE_SHA1    = (1 << 4),
+    ANDROID_CPU_ARM64_FEATURE_SHA2    = (1 << 5),
+    ANDROID_CPU_ARM64_FEATURE_CRC32   = (1 << 6),
+};
+
+/* The bit flags corresponding to the output of android_getCpuFeatures()
+ * when android_getCpuFamily() returns ANDROID_CPU_FAMILY_X86 or
+ * ANDROID_CPU_FAMILY_X86_64.
+ */
+enum {
+    ANDROID_CPU_X86_FEATURE_SSSE3  = (1 << 0),
+    ANDROID_CPU_X86_FEATURE_POPCNT = (1 << 1),
+    ANDROID_CPU_X86_FEATURE_MOVBE  = (1 << 2),
+    ANDROID_CPU_X86_FEATURE_SSE4_1 = (1 << 3),
+    ANDROID_CPU_X86_FEATURE_SSE4_2 = (1 << 4),
+    ANDROID_CPU_X86_FEATURE_AES_NI = (1 << 5),
+    ANDROID_CPU_X86_FEATURE_AVX =    (1 << 6),
+    ANDROID_CPU_X86_FEATURE_RDRAND = (1 << 7),
+    ANDROID_CPU_X86_FEATURE_AVX2 =   (1 << 8),
+    ANDROID_CPU_X86_FEATURE_SHA_NI = (1 << 9),
+};
+
+/* The bit flags corresponding to the output of android_getCpuFeatures()
+ * when android_getCpuFamily() returns ANDROID_CPU_FAMILY_MIPS
+ * or ANDROID_CPU_FAMILY_MIPS64.  Values are:
+ *
+ *   R6:
+ *     CPU executes MIPS Release 6 instructions natively, and
+ *     supports obsoleted R1..R5 instructions only via kernel traps.
+ *
+ *   MSA:
+ *     CPU supports Mips SIMD Architecture instructions.
+ */
+enum {
+    ANDROID_CPU_MIPS_FEATURE_R6    = (1 << 0),
+    ANDROID_CPU_MIPS_FEATURE_MSA   = (1 << 1),
+};
+
+
+/* Return the number of CPU cores detected on this device. */
+extern int android_getCpuCount(void);
+
+/* The following is used to force the CPU count and features
+ * mask in sandboxed processes. Under 4.1 and higher, these processes
+ * cannot access /proc, which is the only way to get information from
+ * the kernel about the current hardware (at least on ARM).
+ *
+ * It _must_ be called only once, and before any android_getCpuXXX
+ * function, any other case will fail.
+ *
+ * This function return 1 on success, and 0 on failure.
+ */
+extern int android_setCpu(int      cpu_count,
+                          uint64_t cpu_features);
+
+#ifdef __arm__
+/* Retrieve the ARM 32-bit CPUID value from the kernel.
+ * Note that this cannot work on sandboxed processes under 4.1 and
+ * higher, unless you called android_setCpuArm() before.
+ */
+extern uint32_t android_getCpuIdArm(void);
+
+/* An ARM-specific variant of android_setCpu() that also allows you
+ * to set the ARM CPUID field.
+ */
+extern int android_setCpuArm(int      cpu_count,
+                             uint64_t cpu_features,
+                             uint32_t cpu_id);
+#endif
+
+__END_DECLS