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 libavcodec/ppc/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 defined(__OpenBSD__)
29#include <sys/param.h>
30#include <sys/sysctl.h>
31#include <machine/cpu.h>
32#elif defined(__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
43int 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 CONFIG_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
85