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/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <stdlib.h>
#include <string.h>
#include "aom_ports/arm.h"
#include "./aom_config.h"
#ifdef WINAPI_FAMILY
#include <winapifamily.h>
#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
#define getenv(x) NULL
#endif
#endif
static int arm_cpu_env_flags(int *flags) {
char *env;
env = getenv("AOM_SIMD_CAPS");
if (env && *env) {
*flags = (int)strtol(env, NULL, 0);
return 0;
}
*flags = 0;
return -1;
}
static int arm_cpu_env_mask(void) {
char *env;
env = getenv("AOM_SIMD_CAPS_MASK");
return env && *env ? (int)strtol(env, NULL, 0) : ~0;
}
#if !CONFIG_RUNTIME_CPU_DETECT
int arm_cpu_caps(void) {
/* This function should actually be a no-op. There is no way to adjust any of
* these because the RTCD tables do not exist: the functions are called
* statically */
int flags;
int mask;
if (!arm_cpu_env_flags(&flags)) {
return flags;
}
mask = arm_cpu_env_mask();
#if HAVE_NEON || HAVE_NEON_ASM
flags |= HAS_NEON;
#endif /* HAVE_NEON || HAVE_NEON_ASM */
return flags & mask;
}
#elif defined(_MSC_VER) /* end !CONFIG_RUNTIME_CPU_DETECT */
/*For GetExceptionCode() and EXCEPTION_ILLEGAL_INSTRUCTION.*/
#define WIN32_LEAN_AND_MEAN
#define WIN32_EXTRA_LEAN
#include <windows.h>
int arm_cpu_caps(void) {
int flags;
int mask;
if (!arm_cpu_env_flags(&flags)) {
return flags;
}
mask = arm_cpu_env_mask();
/* MSVC has no inline __asm support for ARM, but it does let you __emit
* instructions via their assembled hex code.
* All of these instructions should be essentially nops.
*/
#if HAVE_NEON || HAVE_NEON_ASM
if (mask & HAS_NEON) {
__try {
/*VORR q0,q0,q0*/
__emit(0xF2200150);
flags |= HAS_NEON;
} __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
/*Ignore exception.*/
}
}
#endif /* HAVE_NEON || HAVE_NEON_ASM */
return flags & mask;
}
#elif defined(__ANDROID__) /* end _MSC_VER */
#include <cpu-features.h>
int arm_cpu_caps(void) {
int flags;
int mask;
uint64_t features;
if (!arm_cpu_env_flags(&flags)) {
return flags;
}
mask = arm_cpu_env_mask();
features = android_getCpuFeatures();
#if HAVE_NEON || HAVE_NEON_ASM
if (features & ANDROID_CPU_ARM_FEATURE_NEON) flags |= HAS_NEON;
#endif /* HAVE_NEON || HAVE_NEON_ASM */
return flags & mask;
}
#elif defined(__linux__) /* end __ANDROID__ */
#include <stdio.h>
int arm_cpu_caps(void) {
FILE *fin;
int flags;
int mask;
if (!arm_cpu_env_flags(&flags)) {
return flags;
}
mask = arm_cpu_env_mask();
/* Reading /proc/self/auxv would be easier, but that doesn't work reliably
* on Android.
* This also means that detection will fail in Scratchbox.
*/
fin = fopen("/proc/cpuinfo", "r");
if (fin != NULL) {
/* 512 should be enough for anybody (it's even enough for all the flags
* that x86 has accumulated... so far).
*/
char buf[512];
while (fgets(buf, 511, fin) != NULL) {
#if HAVE_NEON || HAVE_NEON_ASM
if (memcmp(buf, "Features", 8) == 0) {
char *p;
p = strstr(buf, " neon");
if (p != NULL && (p[5] == ' ' || p[5] == '\n')) {
flags |= HAS_NEON;
}
}
#endif /* HAVE_NEON || HAVE_NEON_ASM */
}
fclose(fin);
}
return flags & mask;
}
#else /* end __linux__ */
#error \
"--enable-runtime-cpu-detect selected, but no CPU detection method " \
"available for your platform. Reconfigure with --disable-runtime-cpu-detect."
#endif
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