2 * This file is part of Libav.
4 * Libav is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 #include "libavutil/cpu.h"
22 #define CORE_FLAG(f) \
23 (AV_CPU_FLAG_ ## f * (HAVE_ ## f ## _EXTERNAL || HAVE_ ## f ## _INLINE))
25 #define CORE_CPU_FLAGS \
26 (CORE_FLAG(ARMV5TE) | \
28 CORE_FLAG(ARMV6T2) | \
33 #if defined __linux__ || defined __ANDROID__
40 /* Relevant HWCAP values from kernel headers */
41 #define HWCAP_VFP (1 << 6)
42 #define HWCAP_EDSP (1 << 7)
43 #define HWCAP_THUMBEE (1 << 11)
44 #define HWCAP_NEON (1 << 12)
45 #define HWCAP_VFPv3 (1 << 13)
46 #define HWCAP_TLS (1 << 15)
48 static int get_hwcap(uint32_t *hwcap)
50 struct { uint32_t a_type; uint32_t a_val; } auxv;
51 FILE *f = fopen("/proc/self/auxv", "r");
57 while (fread(&auxv, sizeof(auxv), 1, f) > 0) {
58 if (auxv.a_type == AT_HWCAP) {
69 int ff_get_cpu_flags_arm(void)
71 int flags = CORE_CPU_FLAGS;
74 if (get_hwcap(&hwcap) < 0)
77 #define check_cap(cap, flag) do { \
78 if (hwcap & HWCAP_ ## cap) \
79 flags |= AV_CPU_FLAG_ ## flag; \
82 /* No flags explicitly indicate v6 or v6T2 so check others which
84 check_cap(EDSP, ARMV5TE);
85 check_cap(TLS, ARMV6);
86 check_cap(THUMBEE, ARMV6T2);
88 check_cap(VFPv3, VFPV3);
89 check_cap(NEON, NEON);
91 /* The v6 checks above are not reliable so let higher flags
93 if (flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON))
94 flags |= AV_CPU_FLAG_ARMV6T2;
95 if (flags & AV_CPU_FLAG_ARMV6T2)
96 flags |= AV_CPU_FLAG_ARMV6;
103 int ff_get_cpu_flags_arm(void)
105 return AV_CPU_FLAG_ARMV5TE * HAVE_ARMV5TE |
106 AV_CPU_FLAG_ARMV6 * HAVE_ARMV6 |
107 AV_CPU_FLAG_ARMV6T2 * HAVE_ARMV6T2 |
108 AV_CPU_FLAG_VFP * HAVE_VFP |
109 AV_CPU_FLAG_VFPV3 * HAVE_VFPV3 |
110 AV_CPU_FLAG_NEON * HAVE_NEON;