1/*
2 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include <stdlib.h>
12#include <string.h>
13#include "arm.h"
14
15static int arm_cpu_env_flags(int *flags) {
16  char *env;
17  env = getenv("VPX_SIMD_CAPS");
18  if (env && *env) {
19    *flags = (int)strtol(env, NULL, 0);
20    return 0;
21  }
22  *flags = 0;
23  return -1;
24}
25
26static int arm_cpu_env_mask(void) {
27  char *env;
28  env = getenv("VPX_SIMD_CAPS_MASK");
29  return env && *env ? (int)strtol(env, NULL, 0) : ~0;
30}
31
32#if !CONFIG_RUNTIME_CPU_DETECT
33
34int arm_cpu_caps(void) {
35  /* This function should actually be a no-op. There is no way to adjust any of
36   * these because the RTCD tables do not exist: the functions are called
37   * statically */
38  int flags;
39  int mask;
40  if (!arm_cpu_env_flags(&flags)) {
41    return flags;
42  }
43  mask = arm_cpu_env_mask();
44#if HAVE_EDSP
45  flags |= HAS_EDSP;
46#endif /* HAVE_EDSP */
47#if HAVE_MEDIA
48  flags |= HAS_MEDIA;
49#endif /* HAVE_MEDIA */
50#if HAVE_NEON
51  flags |= HAS_NEON;
52#endif /* HAVE_NEON */
53  return flags & mask;
54}
55
56#elif defined(_MSC_VER) /* end !CONFIG_RUNTIME_CPU_DETECT */
57/*For GetExceptionCode() and EXCEPTION_ILLEGAL_INSTRUCTION.*/
58#define WIN32_LEAN_AND_MEAN
59#define WIN32_EXTRA_LEAN
60#include <windows.h>
61
62int arm_cpu_caps(void) {
63  int flags;
64  int mask;
65  if (!arm_cpu_env_flags(&flags)) {
66    return flags;
67  }
68  mask = arm_cpu_env_mask();
69  /* MSVC has no inline __asm support for ARM, but it does let you __emit
70   *  instructions via their assembled hex code.
71   * All of these instructions should be essentially nops.
72   */
73#if HAVE_EDSP
74  if (mask & HAS_EDSP) {
75    __try {
76      /*PLD [r13]*/
77      __emit(0xF5DDF000);
78      flags |= HAS_EDSP;
79    } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
80      /*Ignore exception.*/
81    }
82  }
83#if HAVE_MEDIA
84  if (mask & HAS_MEDIA)
85    __try {
86      /*SHADD8 r3,r3,r3*/
87      __emit(0xE6333F93);
88      flags |= HAS_MEDIA;
89    } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
90    /*Ignore exception.*/
91  }
92}
93#if HAVE_NEON
94if (mask &HAS_NEON) {
95  __try {
96    /*VORR q0,q0,q0*/
97    __emit(0xF2200150);
98    flags |= HAS_NEON;
99  } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
100    /*Ignore exception.*/
101  }
102}
103#endif /* HAVE_NEON */
104#endif /* HAVE_MEDIA */
105#endif /* HAVE_EDSP */
106return flags & mask;
107}
108
109#elif defined(__ANDROID__) /* end _MSC_VER */
110#include <cpu-features.h>
111
112int arm_cpu_caps(void) {
113  int flags;
114  int mask;
115  uint64_t features;
116  if (!arm_cpu_env_flags(&flags)) {
117    return flags;
118  }
119  mask = arm_cpu_env_mask();
120  features = android_getCpuFeatures();
121
122#if HAVE_EDSP
123  flags |= HAS_EDSP;
124#endif /* HAVE_EDSP */
125#if HAVE_MEDIA
126  flags |= HAS_MEDIA;
127#endif /* HAVE_MEDIA */
128#if HAVE_NEON
129  if (features & ANDROID_CPU_ARM_FEATURE_NEON)
130    flags |= HAS_NEON;
131#endif /* HAVE_NEON */
132  return flags & mask;
133}
134
135#elif defined(__linux__) /* end __ANDROID__ */
136
137#include <stdio.h>
138
139int arm_cpu_caps(void) {
140  FILE *fin;
141  int flags;
142  int mask;
143  if (!arm_cpu_env_flags(&flags)) {
144    return flags;
145  }
146  mask = arm_cpu_env_mask();
147  /* Reading /proc/self/auxv would be easier, but that doesn't work reliably
148   *  on Android.
149   * This also means that detection will fail in Scratchbox.
150   */
151  fin = fopen("/proc/cpuinfo", "r");
152  if (fin != NULL) {
153    /* 512 should be enough for anybody (it's even enough for all the flags
154     * that x86 has accumulated... so far).
155     */
156    char buf[512];
157    while (fgets(buf, 511, fin) != NULL) {
158#if HAVE_EDSP || HAVE_NEON
159      if (memcmp(buf, "Features", 8) == 0) {
160        char *p;
161#if HAVE_EDSP
162        p = strstr(buf, " edsp");
163        if (p != NULL && (p[5] == ' ' || p[5] == '\n')) {
164          flags |= HAS_EDSP;
165        }
166#if HAVE_NEON
167        p = strstr(buf, " neon");
168        if (p != NULL && (p[5] == ' ' || p[5] == '\n')) {
169          flags |= HAS_NEON;
170        }
171#endif /* HAVE_NEON */
172#endif /* HAVE_EDSP */
173      }
174#endif /* HAVE_EDSP || HAVE_NEON */
175#if HAVE_MEDIA
176      if (memcmp(buf, "CPU architecture:", 17) == 0) {
177        int version;
178        version = atoi(buf + 17);
179        if (version >= 6) {
180          flags |= HAS_MEDIA;
181        }
182      }
183#endif /* HAVE_MEDIA */
184    }
185    fclose(fin);
186  }
187  return flags & mask;
188}
189#else /* end __linux__ */
190#error "--enable-runtime-cpu-detect selected, but no CPU detection method " \
191"available for your platform. Reconfigure with --disable-runtime-cpu-detect."
192#endif
193