mirror of
https://github.com/FFmpeg/FFmpeg.git
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96 lines
2.3 KiB
C
96 lines
2.3 KiB
C
/*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file check_altivec.c
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* Checks for AltiVec presence.
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*/
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#ifdef __APPLE__
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#include <sys/sysctl.h>
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#elif __AMIGAOS4__
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#include <exec/exec.h>
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#include <interfaces/exec.h>
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#include <proto/exec.h>
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#else
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#include <signal.h>
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#include <setjmp.h>
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static sigjmp_buf jmpbuf;
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static volatile sig_atomic_t canjump = 0;
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static void sigill_handler (int sig)
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{
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if (!canjump) {
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signal (sig, SIG_DFL);
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raise (sig);
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}
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canjump = 0;
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siglongjmp (jmpbuf, 1);
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}
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#endif /* __APPLE__ */
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/**
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* This function MAY rely on signal() or fork() in order to make sure altivec
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* is present
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*/
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int has_altivec(void)
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{
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#ifdef __AMIGAOS4__
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ULONG result = 0;
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extern struct ExecIFace *IExec;
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IExec->GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
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if (result == VECTORTYPE_ALTIVEC) return 1;
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return 0;
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#elif __APPLE__
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int sels[2] = {CTL_HW, HW_VECTORUNIT};
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int has_vu = 0;
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size_t len = sizeof(has_vu);
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int err;
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err = sysctl(sels, 2, &has_vu, &len, NULL, 0);
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if (err == 0) return (has_vu != 0);
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return 0;
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#else
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/* Do it the brute-force way, borrowed from the libmpeg2 library. */
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{
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signal (SIGILL, sigill_handler);
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if (sigsetjmp (jmpbuf, 1)) {
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signal (SIGILL, SIG_DFL);
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} else {
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canjump = 1;
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asm volatile ("mtspr 256, %0\n\t"
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"vand %%v0, %%v0, %%v0"
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:
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: "r" (-1));
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signal (SIGILL, SIG_DFL);
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return 1;
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}
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}
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return 0;
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#endif /* __AMIGAOS4__ */
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}
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