417c768df430922efad27affa310ca54ab7c3543
[libav.git] / libavcodec / ppc / check_altivec.c
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
20 /**
21 * @file check_altivec.c
22 * Checks for AltiVec presence.
23 */
24
25 #ifdef __APPLE__
26 #undef _POSIX_C_SOURCE
27 #include <sys/sysctl.h>
28 #elif __OpenBSD__
29 #include <sys/param.h>
30 #include <sys/sysctl.h>
31 #include <machine/cpu.h>
32 #elif __AMIGAOS4__
33 #include <exec/exec.h>
34 #include <interfaces/exec.h>
35 #include <proto/exec.h>
36 #endif /* __APPLE__ */
37
38 /**
39 * This function MAY rely on signal() or fork() in order to make sure AltiVec
40 * is present.
41 */
42
43 int has_altivec(void)
44 {
45 #ifdef __AMIGAOS4__
46 ULONG result = 0;
47 extern struct ExecIFace *IExec;
48
49 IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
50 if (result == VECTORTYPE_ALTIVEC) return 1;
51 return 0;
52 #elif defined(__APPLE__) || defined(__OpenBSD__)
53 #ifdef __OpenBSD__
54 int sels[2] = {CTL_MACHDEP, CPU_ALTIVEC};
55 #else
56 int sels[2] = {CTL_HW, HW_VECTORUNIT};
57 #endif
58 int has_vu = 0;
59 size_t len = sizeof(has_vu);
60 int err;
61
62 err = sysctl(sels, 2, &has_vu, &len, NULL, 0);
63
64 if (err == 0) return has_vu != 0;
65 return 0;
66 #elif defined(RUNTIME_CPUDETECT)
67 int proc_ver;
68 // Support of mfspr PVR emulation added in Linux 2.6.17.
69 __asm__ volatile("mfspr %0, 287" : "=r" (proc_ver));
70 proc_ver >>= 16;
71 if (proc_ver & 0x8000 ||
72 proc_ver == 0x000c ||
73 proc_ver == 0x0039 || proc_ver == 0x003c ||
74 proc_ver == 0x0044 || proc_ver == 0x0045 ||
75 proc_ver == 0x0070)
76 return 1;
77 return 0;
78 #else
79 // Since we were compiled for AltiVec, just assume we have it
80 // until someone comes up with a proper way (not involving signal hacks).
81 return 1;
82 #endif /* __AMIGAOS4__ */
83 }
84