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