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/*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/cpu.h"
#include "config.h"
#define CORE_FLAG(f) \
(AV_CPU_FLAG_ ## f * (HAVE_ ## f ## _EXTERNAL || HAVE_ ## f ## _INLINE))
#define CORE_CPU_FLAGS \
(CORE_FLAG(ARMV5TE) | \
CORE_FLAG(ARMV6) | \
CORE_FLAG(ARMV6T2) | \
CORE_FLAG(VFP) | \
CORE_FLAG(VFPV3) | \
CORE_FLAG(NEON))
#if defined __linux__ || defined __ANDROID__
#include <stdint.h>
#include <stdio.h>
#define AT_HWCAP 16
/* Relevant HWCAP values from kernel headers */
#define HWCAP_VFP (1 << 6)
#define HWCAP_EDSP (1 << 7)
#define HWCAP_THUMBEE (1 << 11)
#define HWCAP_NEON (1 << 12)
#define HWCAP_VFPv3 (1 << 13)
#define HWCAP_TLS (1 << 15)
static int get_hwcap(uint32_t *hwcap)
{
struct { uint32_t a_type; uint32_t a_val; } auxv;
FILE *f = fopen("/proc/self/auxv", "r");
int err = -1;
if (!f)
return -1;
while (fread(&auxv, sizeof(auxv), 1, f) > 0) {
if (auxv.a_type == AT_HWCAP) {
*hwcap = auxv.a_val;
err = 0;
break;
}
}
fclose(f);
return err;
}
int ff_get_cpu_flags_arm(void)
{
int flags = CORE_CPU_FLAGS;
uint32_t hwcap;
if (get_hwcap(&hwcap) < 0)
return flags;
#define check_cap(cap, flag) do { \
if (hwcap & HWCAP_ ## cap) \
flags |= AV_CPU_FLAG_ ## flag; \
} while (0)
/* No flags explicitly indicate v6 or v6T2 so check others which
imply support. */
check_cap(EDSP, ARMV5TE);
check_cap(TLS, ARMV6);
check_cap(THUMBEE, ARMV6T2);
check_cap(VFP, VFP);
check_cap(VFPv3, VFPV3);
check_cap(NEON, NEON);
/* The v6 checks above are not reliable so let higher flags
trickle down. */
if (flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON))
flags |= AV_CPU_FLAG_ARMV6T2;
if (flags & AV_CPU_FLAG_ARMV6T2)
flags |= AV_CPU_FLAG_ARMV6;
return flags;
}
#else
int ff_get_cpu_flags_arm(void)
{
return AV_CPU_FLAG_ARMV5TE * HAVE_ARMV5TE |
AV_CPU_FLAG_ARMV6 * HAVE_ARMV6 |
AV_CPU_FLAG_ARMV6T2 * HAVE_ARMV6T2 |
AV_CPU_FLAG_VFP * HAVE_VFP |
AV_CPU_FLAG_VFPV3 * HAVE_VFPV3 |
AV_CPU_FLAG_NEON * HAVE_NEON;
}
#endif
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