vpx_ports/arm_cpudetect.c

   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
  15 #ifdef WINAPI_FAMILY
  16 #include <winapifamily.h>
  17 #if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
  18 #define getenv(x) NULL
  19 #endif
  20 #endif
  21
  22 static int arm_cpu_env_flags(int *flags) {
  23   char *env;
  24   env = getenv("VPX_SIMD_CAPS");
  25   if (env && *env) {
  26     *flags = (int)strtol(env, NULL, 0);
  27     return 0;
  28   }
  29   *flags = 0;
  30   return -1;
  31 }
  32
  33 static int arm_cpu_env_mask(void) {
  34   char *env;
  35   env = getenv("VPX_SIMD_CAPS_MASK");
  36   return env && *env ? (int)strtol(env, NULL, 0) : ~0;
  37 }
  38
  39 #if !CONFIG_RUNTIME_CPU_DETECT
  40
  41 int arm_cpu_caps(void) {
  42   /* This function should actually be a no-op. There is no way to adjust any of
  43    * these because the RTCD tables do not exist: the functions are called
  44    * statically */
  45   int flags;
  46   int mask;
  47   if (!arm_cpu_env_flags(&flags)) {
  48     return flags;
  49   }
  50   mask = arm_cpu_env_mask();
  51 #if HAVE_EDSP
  52   flags |= HAS_EDSP;
  53 #endif /* HAVE_EDSP */
  54 #if HAVE_MEDIA
  55   flags |= HAS_MEDIA;
  56 #endif /* HAVE_MEDIA */
  57 #if HAVE_NEON
  58   flags |= HAS_NEON;
  59 #endif /* HAVE_NEON */
  60   return flags & mask;
  61 }
  62
  63 #elif defined(_MSC_VER) /* end !CONFIG_RUNTIME_CPU_DETECT */
  64 /*For GetExceptionCode() and EXCEPTION_ILLEGAL_INSTRUCTION.*/
  65 #define WIN32_LEAN_AND_MEAN
  66 #define WIN32_EXTRA_LEAN
  67 #include <windows.h>
  68
  69 int arm_cpu_caps(void) {
  70   int flags;
  71   int mask;
  72   if (!arm_cpu_env_flags(&flags)) {
  73     return flags;
  74   }
  75   mask = arm_cpu_env_mask();
  76   /* MSVC has no inline __asm support for ARM, but it does let you __emit
  77    *  instructions via their assembled hex code.
  78    * All of these instructions should be essentially nops.
  79    */
  80 #if HAVE_EDSP
  81   if (mask & HAS_EDSP) {
  82     __try {
  83       /*PLD [r13]*/
  84       __emit(0xF5DDF000);
  85       flags |= HAS_EDSP;
  86     } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
  87       /*Ignore exception.*/
  88     }
  89   }
  90 #if HAVE_MEDIA
  91   if (mask & HAS_MEDIA)
  92     __try {
  93       /*SHADD8 r3,r3,r3*/
  94       __emit(0xE6333F93);
  95       flags |= HAS_MEDIA;
  96     } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
  97     /*Ignore exception.*/
  98   }
  99 }
 100 #if HAVE_NEON
 101 if (mask &HAS_NEON) {
 102   __try {
 103     /*VORR q0,q0,q0*/
 104     __emit(0xF2200150);
 105     flags |= HAS_NEON;
 106   } __except (GetExceptionCode() == EXCEPTION_ILLEGAL_INSTRUCTION) {
 107     /*Ignore exception.*/
 108   }
 109 }
 110 #endif /* HAVE_NEON */
 111 #endif /* HAVE_MEDIA */
 112 #endif /* HAVE_EDSP */
 113 return flags & mask;
 114 }
 115
 116 #elif defined(__ANDROID__) /* end _MSC_VER */
 117 #include <cpu-features.h>
 118
 119 int arm_cpu_caps(void) {
 120   int flags;
 121   int mask;
 122   uint64_t features;
 123   if (!arm_cpu_env_flags(&flags)) {
 124     return flags;
 125   }
 126   mask = arm_cpu_env_mask();
 127   features = android_getCpuFeatures();
 128
 129 #if HAVE_EDSP
 130   flags |= HAS_EDSP;
 131 #endif /* HAVE_EDSP */
 132 #if HAVE_MEDIA
 133   flags |= HAS_MEDIA;
 134 #endif /* HAVE_MEDIA */
 135 #if HAVE_NEON
 136   if (features & ANDROID_CPU_ARM_FEATURE_NEON)
 137     flags |= HAS_NEON;
 138 #endif /* HAVE_NEON */
 139   return flags & mask;
 140 }
 141
 142 #elif defined(__linux__) /* end __ANDROID__ */
 143
 144 #include <stdio.h>
 145
 146 int arm_cpu_caps(void) {
 147   FILE *fin;
 148   int flags;
 149   int mask;
 150   if (!arm_cpu_env_flags(&flags)) {
 151     return flags;
 152   }
 153   mask = arm_cpu_env_mask();
 154   /* Reading /proc/self/auxv would be easier, but that doesn't work reliably
 155    *  on Android.
 156    * This also means that detection will fail in Scratchbox.
 157    */
 158   fin = fopen("/proc/cpuinfo", "r");
 159   if (fin != NULL) {
 160     /* 512 should be enough for anybody (it's even enough for all the flags
 161      * that x86 has accumulated... so far).
 162      */
 163     char buf[512];
 164     while (fgets(buf, 511, fin) != NULL) {
 165 #if HAVE_EDSP || HAVE_NEON
 166       if (memcmp(buf, "Features", 8) == 0) {
 167         char *p;
 168 #if HAVE_EDSP
 169         p = strstr(buf, " edsp");
 170         if (p != NULL && (p[5] == ' ' || p[5] == '\n')) {
 171           flags |= HAS_EDSP;
 172         }
 173 #if HAVE_NEON
 174         p = strstr(buf, " neon");
 175         if (p != NULL && (p[5] == ' ' || p[5] == '\n')) {
 176           flags |= HAS_NEON;
 177         }
 178 #endif /* HAVE_NEON */
 179 #endif /* HAVE_EDSP */
 180       }
 181 #endif /* HAVE_EDSP || HAVE_NEON */
 182 #if HAVE_MEDIA
 183       if (memcmp(buf, "CPU architecture:", 17) == 0) {
 184         int version;
 185         version = atoi(buf + 17);
 186         if (version >= 6) {
 187           flags |= HAS_MEDIA;
 188         }
 189       }
 190 #endif /* HAVE_MEDIA */
 191     }
 192     fclose(fin);
 193   }
 194   return flags & mask;
 195 }
 196 #else /* end __linux__ */
 197 #error "--enable-runtime-cpu-detect selected, but no CPU detection method " \
 198 "available for your platform. Reconfigure with --disable-runtime-cpu-detect."
 199 #endif