naiveproxy/third_party/zlib/arm_features.c
2018-08-14 22:19:20 +00:00

61 lines
1.7 KiB
C

/* arm_features.c -- ARM processor features detection.
*
* Copyright 2018 The Chromium Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the Chromium source repository LICENSE file.
*/
#include "arm_features.h"
#include "zutil.h"
#include <pthread.h>
#include <stdint.h>
#if defined(ARMV8_OS_ANDROID)
#include <cpu-features.h>
#elif defined(ARMV8_OS_LINUX)
#include <asm/hwcap.h>
#include <sys/auxv.h>
#else
#error ### No ARM CPU features detection in your platform/OS
#endif
int ZLIB_INTERNAL arm_cpu_enable_crc32 = 0;
int ZLIB_INTERNAL arm_cpu_enable_pmull = 0;
static pthread_once_t cpu_check_inited_once = PTHREAD_ONCE_INIT;
static void init_arm_features(void)
{
uint64_t flag_crc32 = 0, flag_pmull = 0, capabilities = 0;
#if defined(ARMV8_OS_ANDROID)
flag_crc32 = ANDROID_CPU_ARM_FEATURE_CRC32;
flag_pmull = ANDROID_CPU_ARM_FEATURE_PMULL;
capabilities = android_getCpuFeatures();
#elif defined(ARMV8_OS_LINUX)
#if defined(__aarch64__)
flag_crc32 = HWCAP_CRC32;
flag_pmull = HWCAP_PMULL;
capabilities = getauxval(AT_HWCAP);
#elif defined(__ARM_NEON) || defined(__ARM_NEON__)
/* The use of HWCAP2 is for getting features of newer ARMv8-A SoCs
* while running in 32bits mode (i.e. aarch32).
*/
flag_crc32 = HWCAP2_CRC32;
flag_pmull = HWCAP2_PMULL;
capabilities = getauxval(AT_HWCAP2);
#endif
#endif
if (capabilities & flag_crc32)
arm_cpu_enable_crc32 = 1;
if (capabilities & flag_pmull)
arm_cpu_enable_pmull = 1;
}
void ZLIB_INTERNAL arm_check_features(void)
{
pthread_once(&cpu_check_inited_once, init_arm_features);
}