Libav
cpu.c
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1 /*
2  * This file is part of Libav.
3  *
4  * Libav 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  * Libav 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 Libav; 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(__linux__)
22 #include <asm/cputable.h>
23 #include <linux/auxvec.h>
24 #include <fcntl.h>
25 #include <unistd.h>
26 #elif defined(__OpenBSD__)
27 #include <sys/param.h>
28 #include <sys/sysctl.h>
29 #include <machine/cpu.h>
30 #elif defined(__AMIGAOS4__)
31 #include <exec/exec.h>
32 #include <interfaces/exec.h>
33 #include <proto/exec.h>
34 #endif /* __APPLE__ */
35 
36 #include "libavutil/cpu.h"
37 #include "libavutil/cpu_internal.h"
38 #include "config.h"
39 
45 {
46 #if HAVE_ALTIVEC
47 #ifdef __AMIGAOS4__
48  ULONG result = 0;
49  extern struct ExecIFace *IExec;
50 
51  IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
52  if (result == VECTORTYPE_ALTIVEC)
53  return AV_CPU_FLAG_ALTIVEC;
54  return 0;
55 #elif defined(__APPLE__) || defined(__OpenBSD__)
56 #ifdef __OpenBSD__
57  int sels[2] = {CTL_MACHDEP, CPU_ALTIVEC};
58 #else
59  int sels[2] = {CTL_HW, HW_VECTORUNIT};
60 #endif
61  int has_vu = 0;
62  size_t len = sizeof(has_vu);
63  int err;
64 
65  err = sysctl(sels, 2, &has_vu, &len, NULL, 0);
66 
67  if (err == 0)
68  return has_vu ? AV_CPU_FLAG_ALTIVEC : 0;
69  return 0;
70 #elif defined(__linux__)
71  // The linux kernel could have the altivec support disabled
72  // even if the cpu has it.
73  int i, ret = 0;
74  int fd = open("/proc/self/auxv", O_RDONLY);
75  unsigned long buf[64] = { 0 };
76  ssize_t count;
77 
78  if (fd < 0)
79  return 0;
80 
81  while ((count = read(fd, buf, sizeof(buf))) > 0) {
82  for (i = 0; i < count / sizeof(*buf); i += 2) {
83  if (buf[i] == AT_NULL)
84  goto out;
85  if (buf[i] == AT_HWCAP) {
86  if (buf[i + 1] & PPC_FEATURE_HAS_ALTIVEC)
87  ret = AV_CPU_FLAG_ALTIVEC;
88 #ifdef PPC_FEATURE_HAS_VSX
89  if (buf[i + 1] & PPC_FEATURE_HAS_VSX)
90  ret |= AV_CPU_FLAG_VSX;
91 #endif
92 #ifdef PPC_FEATURE_ARCH_2_07
93  if (buf[i + 1] & PPC_FEATURE_HAS_POWER8)
94  ret |= AV_CPU_FLAG_POWER8;
95 #endif
96  goto out;
97  }
98  }
99  }
100 
101 out:
102  close(fd);
103  return ret;
104 #elif CONFIG_RUNTIME_CPUDETECT
105 #define PVR_G4_7400 0x000C
106 #define PVR_G5_970 0x0039
107 #define PVR_G5_970FX 0x003C
108 #define PVR_G5_970MP 0x0044
109 #define PVR_G5_970GX 0x0045
110 #define PVR_POWER6 0x003E
111 #define PVR_POWER7 0x003F
112 #define PVR_POWER8 0x004B
113 #define PVR_CELL_PPU 0x0070
114  int ret = 0;
115  int proc_ver;
116  // Support of mfspr PVR emulation added in Linux 2.6.17.
117  __asm__ volatile("mfspr %0, 287" : "=r" (proc_ver));
118  proc_ver >>= 16;
119  if (proc_ver & 0x8000 ||
120  proc_ver == PVR_G4_7400 ||
121  proc_ver == PVR_G5_970 ||
122  proc_ver == PVR_G5_970FX ||
123  proc_ver == PVR_G5_970MP ||
124  proc_ver == PVR_G5_970GX ||
125  proc_ver == PVR_POWER6 ||
126  proc_ver == PVR_POWER7 ||
127  proc_ver == PVR_POWER8 ||
128  proc_ver == PVR_CELL_PPU)
129  ret = AV_CPU_FLAG_ALTIVEC;
130  if (proc_ver == PVR_POWER7 ||
131  proc_ver == PVR_POWER8)
132  ret |= AV_CPU_FLAG_VSX;
133  if (proc_ver == PVR_POWER8)
134  ret |= AV_CPU_FLAG_POWER8;
135 
136  return ret;
137 #else
138  // Since we were compiled for AltiVec, just assume we have it
139  // until someone comes up with a proper way (not involving signal hacks).
140  return AV_CPU_FLAG_ALTIVEC;
141 #endif /* __AMIGAOS4__ */
142 #endif /* HAVE_ALTIVEC */
143  return 0;
144 }
#define AV_CPU_FLAG_ALTIVEC
standard
Definition: cpu.h:55
int ff_get_cpu_flags_ppc(void)
This function MAY rely on signal() or fork() in order to make sure AltiVec is present.
Definition: cpu.c:44
NULL
Definition: eval.c:55
#define AV_CPU_FLAG_VSX
ISA 2.06.
Definition: cpu.h:56
#define AV_CPU_FLAG_POWER8
ISA 2.07.
Definition: cpu.h:57
int len
FILE * out
Definition: movenc.c:54