summaryrefslogtreecommitdiffstats
path: root/media/libaom/src/aom_ports/arm_cpudetect.c
blob: 5a75bb3484441aae922bd69fae10ebe85934aedc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
/*
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */

#include <stdlib.h>
#include <string.h>
#include "aom_ports/arm.h"
#include "config/aom_config.h"

#ifdef WINAPI_FAMILY
#include <winapifamily.h>
#if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
#define getenv(x) NULL
#endif
#endif

static int arm_cpu_env_flags(int *flags) {
  char *env;
  env = getenv("AOM_SIMD_CAPS");
  if (env && *env) {
    *flags = (int)strtol(env, NULL, 0);
    return 0;
  }
  *flags = 0;
  return -1;
}

static int arm_cpu_env_mask(void) {
  char *env;
  env = getenv("AOM_SIMD_CAPS_MASK");
  return env && *env ? (int)strtol(env, NULL, 0) : ~0;
}

#if !CONFIG_RUNTIME_CPU_DETECT

int aom_arm_cpu_caps(void) {
  /* This function should actually be a no-op. There is no way to adjust any of
   * these because the RTCD tables do not exist: the functions are called
   * statically */
  int flags;
  int mask;
  if (!arm_cpu_env_flags(&flags)) {
    return flags;
  }
  mask = arm_cpu_env_mask();
#if HAVE_NEON
  flags |= HAS_NEON;
#endif /* HAVE_NEON */
  return flags & mask;
}

#elif defined(_MSC_VER) /* end !CONFIG_RUNTIME_CPU_DETECT */
/*For GetExceptionCode() and EXCEPTION_ILLEGAL_INSTRUCTION.*/
#define WIN32_LEAN_AND_MEAN
#define WIN32_EXTRA_LEAN
#include <windows.h>

int aom_arm_cpu_caps(void) {
  int flags;
  int mask;
  if (!arm_cpu_env_flags(&flags)) {
    return flags;
  }
  mask = arm_cpu_env_mask();
/* MSVC has no inline __asm support for ARM, but it does let you __emit
 *  instructions via their assembled hex code.
 * All of these instructions should be essentially nops.
 */
#if HAVE_NEON
  if (mask & HAS_NEON) {
    __try {
      /*VORR q0,q0,q0*/
      __emit(0xF2200150);
      flags |= HAS_NEON;
    } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
      /*Ignore exception.*/
    }
  }
#endif /* HAVE_NEON */
  return flags & mask;
}

#elif defined(__ANDROID__) /* end _MSC_VER */
#include <cpu-features.h>

int aom_arm_cpu_caps(void) {
  int flags;
  int mask;
  uint64_t features;
  if (!arm_cpu_env_flags(&flags)) {
    return flags;
  }
  mask = arm_cpu_env_mask();
  features = android_getCpuFeatures();

#if HAVE_NEON
  if (features & ANDROID_CPU_ARM_FEATURE_NEON) flags |= HAS_NEON;
#endif /* HAVE_NEON */
  return flags & mask;
}

#elif defined(__linux__) /* end __ANDROID__ */

#include <stdio.h>

int aom_arm_cpu_caps(void) {
  FILE *fin;
  int flags;
  int mask;
  if (!arm_cpu_env_flags(&flags)) {
    return flags;
  }
  mask = arm_cpu_env_mask();
  /* Reading /proc/self/auxv would be easier, but that doesn't work reliably
   *  on Android.
   * This also means that detection will fail in Scratchbox.
   */
  fin = fopen("/proc/cpuinfo", "r");
  if (fin != NULL) {
    /* 512 should be enough for anybody (it's even enough for all the flags
     * that x86 has accumulated... so far).
     */
    char buf[512];
    while (fgets(buf, 511, fin) != NULL) {
#if HAVE_NEON
      if (memcmp(buf, "Features", 8) == 0) {
        char *p;
        p = strstr(buf, " neon");
        if (p != NULL && (p[5] == ' ' || p[5] == '\n')) {
          flags |= HAS_NEON;
        }
      }
#endif /* HAVE_NEON */
    }
    fclose(fin);
  }
  return flags & mask;
}
#else  /* end __linux__ */
#error \
    "--enable-runtime-cpu-detect selected, but no CPU detection method " \
"available for your platform. Reconfigure with --disable-runtime-cpu-detect."
#endif