ffmpeg/libavcodec/ppc/check_altivec.c

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/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file check_altivec.c
* Checks for AltiVec presence.
*/
#ifdef __APPLE__
#undef _POSIX_C_SOURCE
#include <sys/sysctl.h>
#elif __OpenBSD__
#include <sys/param.h>
#include <sys/sysctl.h>
#include <machine/cpu.h>
#elif __AMIGAOS4__
#include <exec/exec.h>
#include <interfaces/exec.h>
#include <proto/exec.h>
#endif /* __APPLE__ */
/**
* This function MAY rely on signal() or fork() in order to make sure AltiVec
* is present.
*/
int has_altivec(void)
{
#ifdef __AMIGAOS4__
ULONG result = 0;
extern struct ExecIFace *IExec;
IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
if (result == VECTORTYPE_ALTIVEC) return 1;
return 0;
#elif defined(__APPLE__) || defined(__OpenBSD__)
#ifdef __OpenBSD__
int sels[2] = {CTL_MACHDEP, CPU_ALTIVEC};
#else
int sels[2] = {CTL_HW, HW_VECTORUNIT};
#endif
int has_vu = 0;
size_t len = sizeof(has_vu);
int err;
err = sysctl(sels, 2, &has_vu, &len, NULL, 0);
if (err == 0) return has_vu != 0;
return 0;
#elif defined(RUNTIME_CPUDETECT)
int proc_ver;
// Support of mfspr PVR emulation added in Linux 2.6.17.
__asm__ volatile("mfspr %0, 287" : "=r" (proc_ver));
proc_ver >>= 16;
if (proc_ver & 0x8000 ||
proc_ver == 0x000c ||
proc_ver == 0x0039 || proc_ver == 0x003c ||
proc_ver == 0x0044 || proc_ver == 0x0045 ||
proc_ver == 0x0070)
return 1;
return 0;
#else
// Since we were compiled for AltiVec, just assume we have it
// until someone comes up with a proper way (not involving signal hacks).
return 1;
#endif /* __AMIGAOS4__ */
}