src/linux/cpu.c

   1 /*****************************************************************************
   2  * linux/cpu.c: CPU detection code for Linux
   3  *****************************************************************************
   4  * Copyright (C) 2012 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <vlc_common.h>
  28 #include <vlc_cpu.h>
  29
  30 #undef CPU_FLAGS
  31 #if defined (__arm__)
  32 # define CPU_FLAGS "Features\t:"
  33
  34 #elif defined (__i386__) || defined (__x86_64__)
  35 # define CPU_FLAGS "flags\t\t:"
  36
  37 #elif defined (__powerpc__) || defined (__powerpc64__)
  38 # define CPU_FLAGS "cpu\t\t:"
  39
  40 #endif
  41
  42 #ifdef CPU_FLAGS
  43 static uint32_t cpu_flags = 0;
  44
  45 static void vlc_CPU_init (void)
  46 {
  47     FILE *info = fopen ("/proc/cpuinfo", "rte");
  48     if (info == NULL)
  49         return;
  50
  51     char *line = NULL;
  52     size_t linelen = 0;
  53     uint_fast32_t all_caps = 0xFFFFFFFF;
  54
  55     while (getline (&line, &linelen, info) != -1)
  56     {
  57         char *p = line, *cap;
  58         uint_fast32_t core_caps = 0;
  59
  60 #if defined (__arm__)
  61         unsigned ver;
  62         if (sscanf (line, "Processor\t: ARMv%u", &ver) >= 1 && ver >= 6)
  63             core_caps |= VLC_CPU_ARMv6;
  64 #endif
  65         if (strncmp (line, CPU_FLAGS, strlen (CPU_FLAGS)))
  66             continue;
  67
  68         while ((cap = strsep (&p, " ")) != NULL)
  69         {
  70 #if defined (__arm__)
  71             if (!strcmp (cap, "neon"))
  72                 core_caps |= VLC_CPU_ARM_NEON;
  73
  74 #elif defined (__i386__) || defined (__x86_64__)
  75             if (!strcmp (cap, "mmx"))
  76                 core_caps |= VLC_CPU_MMX;
  77             if (!strcmp (cap, "sse"))
  78                 core_caps |= VLC_CPU_SSE | VLC_CPU_MMXEXT;
  79             if (!strcmp (cap, "mmxext"))
  80                 core_caps |= VLC_CPU_MMXEXT;
  81             if (!strcmp (cap, "sse2"))
  82                 core_caps |= VLC_CPU_SSE2;
  83             if (!strcmp (cap, "pni"))
  84                 core_caps |= VLC_CPU_SSE3;
  85             if (!strcmp (cap, "ssse3"))
  86                 core_caps |= VLC_CPU_SSSE3;
  87             if (!strcmp (cap, "sse4_1"))
  88                 core_caps |= VLC_CPU_SSE4_1;
  89             if (!strcmp (cap, "sse4_2"))
  90                 core_caps |= VLC_CPU_SSE4_2;
  91             if (!strcmp (cap, "sse4a"))
  92                 core_caps |= VLC_CPU_SSE4A;
  93             if (!strcmp (cap, "avx"))
  94                 core_caps |= VLC_CPU_AVX;
  95             if (!strcmp (cap, "avx2"))
  96                 core_caps |= VLC_CPU_AVX2;
  97             if (!strcmp (cap, "3dnow"))
  98                 core_caps |= VLC_CPU_3dNOW;
  99             if (!strcmp (cap, "xop"))
 100                 core_caps |= VLC_CPU_XOP;
 101             if (!strcmp (cap, "fma4"))
 102                 core_caps |= VLC_CPU_FMA4;
 103
 104 #elif defined (__powerpc__) || defined (__powerpc64__)
 105             if (!strcmp (cap, "altivec supported"))
 106                 core_caps |= VLC_CPU_ALTIVEC;
 107 #endif
 108         }
 109
 110         /* Take the intersection of capabilities of each processor */
 111         all_caps &= core_caps;
 112     }
 113     fclose (info);
 114     free (line);
 115
 116     if (all_caps == 0xFFFFFFFF) /* Error parsing of cpuinfo? */
 117         all_caps = 0; /* Do not assume any capability! */
 118
 119     cpu_flags = all_caps;
 120 }
 121
 122 unsigned vlc_CPU (void)
 123 {
 124     static pthread_once_t once = PTHREAD_ONCE_INIT;
 125
 126     pthread_once (&once, vlc_CPU_init);
 127     return cpu_flags;
 128 }
 129 #else /* CPU_FLAGS */
 130 unsigned vlc_CPU (void)
 131 {
 132     return 0;
 133 }
 134 #endif