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cpu.c
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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 "libavutil/cpu_internal.h"
33 #include "config.h"
34 
35 /**
36  * This function MAY rely on signal() or fork() in order to make sure AltiVec
37  * is present.
38  */
40 {
41 #if HAVE_ALTIVEC
42 #ifdef __AMIGAOS4__
43  ULONG result = 0;
44  extern struct ExecIFace *IExec;
45 
46  IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
47  if (result == VECTORTYPE_ALTIVEC)
48  return AV_CPU_FLAG_ALTIVEC;
49  return 0;
50 #elif defined(__APPLE__) || defined(__OpenBSD__)
51 #ifdef __OpenBSD__
52  int sels[2] = {CTL_MACHDEP, CPU_ALTIVEC};
53 #else
54  int sels[2] = {CTL_HW, HW_VECTORUNIT};
55 #endif
56  int has_vu = 0;
57  size_t len = sizeof(has_vu);
58  int err;
59 
60  err = sysctl(sels, 2, &has_vu, &len, NULL, 0);
61 
62  if (err == 0)
63  return has_vu ? AV_CPU_FLAG_ALTIVEC : 0;
64  return 0;
65 #elif CONFIG_RUNTIME_CPUDETECT && defined(__linux__) && !ARCH_PPC64
66  int proc_ver;
67  // Support of mfspr PVR emulation added in Linux 2.6.17.
68  __asm__ volatile("mfspr %0, 287" : "=r" (proc_ver));
69  proc_ver >>= 16;
70  if (proc_ver & 0x8000 ||
71  proc_ver == 0x000c ||
72  proc_ver == 0x0039 || proc_ver == 0x003c ||
73  proc_ver == 0x0044 || proc_ver == 0x0045 ||
74  proc_ver == 0x0070)
75  return AV_CPU_FLAG_ALTIVEC;
76  return 0;
77 #else
78  // Since we were compiled for AltiVec, just assume we have it
79  // until someone comes up with a proper way (not involving signal hacks).
80  return AV_CPU_FLAG_ALTIVEC;
81 #endif /* __AMIGAOS4__ */
82 #endif /* HAVE_ALTIVEC */
83  return 0;
84 }