FFmpeg
cpu.c
Go to the documentation of this file.
1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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"
20 #include "libavutil/cpu_internal.h"
21 #include "config.h"
22 
23 #if HAVE_GETAUXVAL || HAVE_ELF_AUX_INFO
24 #include <stdint.h>
25 #include <sys/auxv.h>
26 
27 #define HWCAP_AARCH64_ASIMDDP (1 << 20)
28 #define HWCAP_AARCH64_SVE (1 << 22)
29 #define HWCAP2_AARCH64_SVE2 (1 << 1)
30 #define HWCAP2_AARCH64_I8MM (1 << 13)
31 
32 static int detect_flags(void)
33 {
34  int flags = 0;
35 
36  unsigned long hwcap = ff_getauxval(AT_HWCAP);
37  unsigned long hwcap2 = ff_getauxval(AT_HWCAP2);
38 
39  if (hwcap & HWCAP_AARCH64_ASIMDDP)
41  if (hwcap & HWCAP_AARCH64_SVE)
43  if (hwcap2 & HWCAP2_AARCH64_SVE2)
45  if (hwcap2 & HWCAP2_AARCH64_I8MM)
47 
48  return flags;
49 }
50 
51 #elif defined(__APPLE__) && HAVE_SYSCTLBYNAME
52 #include <sys/sysctl.h>
53 
54 static int have_feature(const char *feature) {
55  uint32_t value = 0;
56  size_t size = sizeof(value);
57  if (!sysctlbyname(feature, &value, &size, NULL, 0))
58  return value;
59  return 0;
60 }
61 
62 static int detect_flags(void)
63 {
64  int flags = 0;
65 
66  if (have_feature("hw.optional.arm.FEAT_DotProd"))
68  if (have_feature("hw.optional.arm.FEAT_I8MM"))
70 
71  return flags;
72 }
73 
74 #elif defined(__OpenBSD__)
75 #include <machine/armreg.h>
76 #include <machine/cpu.h>
77 #include <sys/types.h>
78 #include <sys/sysctl.h>
79 
80 static int detect_flags(void)
81 {
82  int flags = 0;
83 
84 #ifdef CPU_ID_AA64ISAR0
85  int mib[2];
86  uint64_t isar0;
87  uint64_t isar1;
88  size_t len;
89 
90  mib[0] = CTL_MACHDEP;
91  mib[1] = CPU_ID_AA64ISAR0;
92  len = sizeof(isar0);
93  if (sysctl(mib, 2, &isar0, &len, NULL, 0) != -1) {
94  if (ID_AA64ISAR0_DP(isar0) >= ID_AA64ISAR0_DP_IMPL)
96  }
97 
98  mib[0] = CTL_MACHDEP;
99  mib[1] = CPU_ID_AA64ISAR1;
100  len = sizeof(isar1);
101  if (sysctl(mib, 2, &isar1, &len, NULL, 0) != -1) {
102 #ifdef ID_AA64ISAR1_I8MM_IMPL
103  if (ID_AA64ISAR1_I8MM(isar1) >= ID_AA64ISAR1_I8MM_IMPL)
105 #endif
106  }
107 #endif
108 
109  return flags;
110 }
111 
112 #elif defined(_WIN32)
113 #include <windows.h>
114 
115 static int detect_flags(void)
116 {
117  int flags = 0;
118 #ifdef PF_ARM_V82_DP_INSTRUCTIONS_AVAILABLE
119  if (IsProcessorFeaturePresent(PF_ARM_V82_DP_INSTRUCTIONS_AVAILABLE))
121 #endif
122 #ifdef PF_ARM_SVE_I8MM_INSTRUCTIONS_AVAILABLE
123  /* There's no PF_* flag that indicates whether plain I8MM is available
124  * or not. But if SVE_I8MM is available, that also implies that
125  * regular I8MM is available. */
126  if (IsProcessorFeaturePresent(PF_ARM_SVE_I8MM_INSTRUCTIONS_AVAILABLE))
128 #endif
129 #ifdef PF_ARM_SVE_INSTRUCTIONS_AVAILABLE
130  if (IsProcessorFeaturePresent(PF_ARM_SVE_INSTRUCTIONS_AVAILABLE))
132 #endif
133 #ifdef PF_ARM_SVE2_INSTRUCTIONS_AVAILABLE
134  if (IsProcessorFeaturePresent(PF_ARM_SVE2_INSTRUCTIONS_AVAILABLE))
136 #endif
137  return flags;
138 }
139 #else
140 
141 static int detect_flags(void)
142 {
143  return 0;
144 }
145 
146 #endif
147 
149 {
150  int flags = AV_CPU_FLAG_ARMV8 * HAVE_ARMV8 |
151  AV_CPU_FLAG_NEON * HAVE_NEON;
152 
153 #ifdef __ARM_FEATURE_DOTPROD
155 #endif
156 #ifdef __ARM_FEATURE_MATMUL_INT8
158 #endif
159 #ifdef __ARM_FEATURE_SVE
161 #endif
162 #ifdef __ARM_FEATURE_SVE2
164 #endif
165 
166  flags |= detect_flags();
167 
168  return flags;
169 }
170 
172 {
173  int flags = av_get_cpu_flags();
174 
175  if (flags & AV_CPU_FLAG_NEON)
176  return 16;
177 
178  return 8;
179 }
AT_HWCAP
#define AT_HWCAP
Definition: cpu.c:50
AV_CPU_FLAG_SVE2
#define AV_CPU_FLAG_SVE2
Definition: cpu.h:76
AV_CPU_FLAG_SVE
#define AV_CPU_FLAG_SVE
Definition: cpu.h:75
AV_CPU_FLAG_DOTPROD
#define AV_CPU_FLAG_DOTPROD
Definition: cpu.h:73
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:109
cpu_internal.h
ff_get_cpu_max_align_aarch64
size_t ff_get_cpu_max_align_aarch64(void)
Definition: cpu.c:171
ff_getauxval
unsigned long ff_getauxval(unsigned long type)
Definition: cpu.c:301
NULL
#define NULL
Definition: coverity.c:32
ff_get_cpu_flags_aarch64
int ff_get_cpu_flags_aarch64(void)
Definition: cpu.c:148
detect_flags
static int detect_flags(void)
Definition: cpu.c:141
AV_CPU_FLAG_I8MM
#define AV_CPU_FLAG_I8MM
Definition: cpu.h:74
cpu.h
AV_CPU_FLAG_NEON
#define AV_CPU_FLAG_NEON
Definition: cpu.h:70
size
int size
Definition: twinvq_data.h:10344
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
AV_CPU_FLAG_ARMV8
#define AV_CPU_FLAG_ARMV8
Definition: cpu.h:71
len
int len
Definition: vorbis_enc_data.h:426
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
AT_HWCAP2
#define AT_HWCAP2
Definition: cpu.c:53