FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
cpu.c
Go to the documentation of this file.
1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifdef __APPLE__
20 #include <sys/sysctl.h>
21 #elif defined(__OpenBSD__)
22 #include <sys/param.h>
23 #include <sys/sysctl.h>
24 #include <machine/cpu.h>
25 #elif defined(__AMIGAOS4__)
26 #include <exec/exec.h>
27 #include <interfaces/exec.h>
28 #include <proto/exec.h>
29 #endif /* __APPLE__ */
30 
31 #include "libavutil/cpu.h"
32 #include "config.h"
33 
34 /**
35  * This function MAY rely on signal() or fork() in order to make sure AltiVec
36  * is present.
37  */
39 {
40 #if HAVE_ALTIVEC
41 #ifdef __AMIGAOS4__
42  ULONG result = 0;
43  extern struct ExecIFace *IExec;
44 
45  IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
46  if (result == VECTORTYPE_ALTIVEC)
47  return AV_CPU_FLAG_ALTIVEC;
48  return 0;
49 #elif defined(__APPLE__) || defined(__OpenBSD__)
50 #ifdef __OpenBSD__
51  int sels[2] = {CTL_MACHDEP, CPU_ALTIVEC};
52 #else
53  int sels[2] = {CTL_HW, HW_VECTORUNIT};
54 #endif
55  int has_vu = 0;
56  size_t len = sizeof(has_vu);
57  int err;
58 
59  err = sysctl(sels, 2, &has_vu, &len, NULL, 0);
60 
61  if (err == 0)
62  return has_vu ? AV_CPU_FLAG_ALTIVEC : 0;
63  return 0;
64 #elif CONFIG_RUNTIME_CPUDETECT && defined(__linux__) && !ARCH_PPC64
65  int proc_ver;
66  // Support of mfspr PVR emulation added in Linux 2.6.17.
67  __asm__ volatile("mfspr %0, 287" : "=r" (proc_ver));
68  proc_ver >>= 16;
69  if (proc_ver & 0x8000 ||
70  proc_ver == 0x000c ||
71  proc_ver == 0x0039 || proc_ver == 0x003c ||
72  proc_ver == 0x0044 || proc_ver == 0x0045 ||
73  proc_ver == 0x0070)
74  return AV_CPU_FLAG_ALTIVEC;
75  return 0;
76 #else
77  // Since we were compiled for AltiVec, just assume we have it
78  // until someone comes up with a proper way (not involving signal hacks).
79  return AV_CPU_FLAG_ALTIVEC;
80 #endif /* __AMIGAOS4__ */
81 #endif /* HAVE_ALTIVEC */
82  return 0;
83 }