cpu: split flag checks per arch in av_cpu_max_align()
[libav.git] / libavutil / arm / cpu.c
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1/*
2 * This file is part of Libav.
3 *
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.
8 *
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.
13 *
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
17 */
18
19#include "libavutil/cpu.h"
b78b10c4 20#include "libavutil/cpu_internal.h"
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21#include "config.h"
22
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23#define CORE_FLAG(f) \
24 (AV_CPU_FLAG_ ## f * (HAVE_ ## f ## _EXTERNAL || HAVE_ ## f ## _INLINE))
25
26#define CORE_CPU_FLAGS \
27 (CORE_FLAG(ARMV5TE) | \
28 CORE_FLAG(ARMV6) | \
29 CORE_FLAG(ARMV6T2) | \
30 CORE_FLAG(VFP) | \
31 CORE_FLAG(VFPV3) | \
32 CORE_FLAG(NEON))
33
34#if defined __linux__ || defined __ANDROID__
35
36#include <stdint.h>
37#include <stdio.h>
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38#include <string.h>
39#include "libavutil/avstring.h"
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40
41#define AT_HWCAP 16
42
43/* Relevant HWCAP values from kernel headers */
44#define HWCAP_VFP (1 << 6)
45#define HWCAP_EDSP (1 << 7)
46#define HWCAP_THUMBEE (1 << 11)
47#define HWCAP_NEON (1 << 12)
48#define HWCAP_VFPv3 (1 << 13)
49#define HWCAP_TLS (1 << 15)
50
51static int get_hwcap(uint32_t *hwcap)
52{
53 struct { uint32_t a_type; uint32_t a_val; } auxv;
54 FILE *f = fopen("/proc/self/auxv", "r");
55 int err = -1;
56
57 if (!f)
58 return -1;
59
60 while (fread(&auxv, sizeof(auxv), 1, f) > 0) {
61 if (auxv.a_type == AT_HWCAP) {
62 *hwcap = auxv.a_val;
63 err = 0;
64 break;
65 }
66 }
67
68 fclose(f);
69 return err;
70}
71
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72static int get_cpuinfo(uint32_t *hwcap)
73{
74 FILE *f = fopen("/proc/cpuinfo", "r");
75 char buf[200];
76
77 if (!f)
78 return -1;
79
80 *hwcap = 0;
81 while (fgets(buf, sizeof(buf), f)) {
82 if (av_strstart(buf, "Features", NULL)) {
83 if (strstr(buf, " edsp "))
84 *hwcap |= HWCAP_EDSP;
85 if (strstr(buf, " tls "))
86 *hwcap |= HWCAP_TLS;
87 if (strstr(buf, " thumbee "))
88 *hwcap |= HWCAP_THUMBEE;
89 if (strstr(buf, " vfp "))
90 *hwcap |= HWCAP_VFP;
91 if (strstr(buf, " vfpv3 "))
92 *hwcap |= HWCAP_VFPv3;
7b0c7c91 93 if (strstr(buf, " neon ") || strstr(buf, " asimd "))
ab8f1a69 94 *hwcap |= HWCAP_NEON;
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95 if (strstr(buf, " fp ")) // Listed on 64 bit ARMv8 kernels
96 *hwcap |= HWCAP_VFP | HWCAP_VFPv3;
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97 break;
98 }
99 }
100 fclose(f);
101 return 0;
102}
103
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104int ff_get_cpu_flags_arm(void)
105{
106 int flags = CORE_CPU_FLAGS;
107 uint32_t hwcap;
108
109 if (get_hwcap(&hwcap) < 0)
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110 if (get_cpuinfo(&hwcap) < 0)
111 return flags;
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112
113#define check_cap(cap, flag) do { \
114 if (hwcap & HWCAP_ ## cap) \
115 flags |= AV_CPU_FLAG_ ## flag; \
116 } while (0)
117
118 /* No flags explicitly indicate v6 or v6T2 so check others which
119 imply support. */
120 check_cap(EDSP, ARMV5TE);
121 check_cap(TLS, ARMV6);
122 check_cap(THUMBEE, ARMV6T2);
123 check_cap(VFP, VFP);
124 check_cap(VFPv3, VFPV3);
125 check_cap(NEON, NEON);
126
127 /* The v6 checks above are not reliable so let higher flags
128 trickle down. */
129 if (flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON))
130 flags |= AV_CPU_FLAG_ARMV6T2;
131 if (flags & AV_CPU_FLAG_ARMV6T2)
132 flags |= AV_CPU_FLAG_ARMV6;
133
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134 /* set the virtual VFPv2 vector mode flag */
135 if ((flags & AV_CPU_FLAG_VFP) && !(flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON)))
136 flags |= AV_CPU_FLAG_VFP_VM;
137
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138 return flags;
139}
140
141#else
142
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143int ff_get_cpu_flags_arm(void)
144{
145 return AV_CPU_FLAG_ARMV5TE * HAVE_ARMV5TE |
146 AV_CPU_FLAG_ARMV6 * HAVE_ARMV6 |
147 AV_CPU_FLAG_ARMV6T2 * HAVE_ARMV6T2 |
b3267559 148 AV_CPU_FLAG_VFP * HAVE_VFP |
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149 AV_CPU_FLAG_VFPV3 * HAVE_VFPV3 |
150 AV_CPU_FLAG_NEON * HAVE_NEON;
151}
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152
153#endif
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154
155size_t ff_get_cpu_max_align_arm(void)
156{
157 int flags = av_get_cpu_flags();
158
159 if (flags & AV_CPU_FLAG_NEON)
160 return 16;
161 return 8;
162}