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/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/cpu.h"
#include "libavutil/cpu_internal.h"
#include "config.h"
#if (defined(__linux__) || defined(__ANDROID__)) && HAVE_GETAUXVAL
#include <stdint.h>
#include <sys/auxv.h>
#define get_cpu_feature_reg(reg, val) \
__asm__("mrs %0, " #reg : "=r" (val))
static int detect_flags(void)
{
int flags = 0;
#if defined(HWCAP_CPUID)
unsigned long hwcap = getauxval(AT_HWCAP);
// We can check for DOTPROD and I8MM using HWCAP_ASIMDDP and
// HWCAP2_I8MM too, avoiding to read the CPUID registers (which triggers
// a trap, handled by the kernel). However the HWCAP_* defines for these
// extensions are added much later than HWCAP_CPUID, so the userland
// headers might lack support for them even if the binary later is run
// on hardware that does support it (and where the kernel might support
// HWCAP_CPUID).
// See https://www.kernel.org/doc/html/latest/arm64/cpu-feature-registers.html
if (hwcap & HWCAP_CPUID) {
uint64_t tmp;
get_cpu_feature_reg(ID_AA64ISAR0_EL1, tmp);
if (((tmp >> 44) & 0xf) == 0x1)
flags |= AV_CPU_FLAG_DOTPROD;
get_cpu_feature_reg(ID_AA64ISAR1_EL1, tmp);
if (((tmp >> 52) & 0xf) == 0x1)
flags |= AV_CPU_FLAG_I8MM;
}
#endif
return flags;
}
#elif defined(__APPLE__) && HAVE_SYSCTLBYNAME
#include <sys/sysctl.h>
static int detect_flags(void)
{
uint32_t value = 0;
size_t size;
int flags = 0;
size = sizeof(value);
if (!sysctlbyname("hw.optional.arm.FEAT_DotProd", &value, &size, NULL, 0)) {
if (value)
flags |= AV_CPU_FLAG_DOTPROD;
}
size = sizeof(value);
if (!sysctlbyname("hw.optional.arm.FEAT_I8MM", &value, &size, NULL, 0)) {
if (value)
flags |= AV_CPU_FLAG_I8MM;
}
return flags;
}
#elif defined(_WIN32)
#include <windows.h>
static int detect_flags(void)
{
int flags = 0;
#ifdef PF_ARM_V82_DP_INSTRUCTIONS_AVAILABLE
if (IsProcessorFeaturePresent(PF_ARM_V82_DP_INSTRUCTIONS_AVAILABLE))
flags |= AV_CPU_FLAG_DOTPROD;
#endif
return flags;
}
#else
static int detect_flags(void)
{
return 0;
}
#endif
int ff_get_cpu_flags_aarch64(void)
{
int flags = AV_CPU_FLAG_ARMV8 * HAVE_ARMV8 |
AV_CPU_FLAG_NEON * HAVE_NEON;
#ifdef __ARM_FEATURE_DOTPROD
flags |= AV_CPU_FLAG_DOTPROD;
#endif
#ifdef __ARM_FEATURE_MATMUL_INT8
flags |= AV_CPU_FLAG_I8MM;
#endif
flags |= detect_flags();
return flags;
}
size_t ff_get_cpu_max_align_aarch64(void)
{
int flags = av_get_cpu_flags();
if (flags & AV_CPU_FLAG_NEON)
return 16;
return 8;
}
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