chromium/third_party/ffmpeg/libavutil/x86/cpu.c

/*
 * CPU detection code, extracted from mmx.h
 * (c)1997-99 by H. Dietz and R. Fisher
 * Converted to C and improved by Fabrice Bellard.
 *
 * 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
 */

#include <stdlib.h>
#include <string.h>

#include "libavutil/x86/asm.h"
#include "libavutil/x86/cpu.h"
#include "libavutil/cpu.h"
#include "libavutil/cpu_internal.h"

#if HAVE_X86ASM

#define cpuid(index, eax, ebx, ecx, edx) …

#define xgetbv(index, eax, edx) …

#elif HAVE_INLINE_ASM

/* ebx saving is necessary for PIC. gcc seems unable to see it alone */
#define cpuid …

#define xgetbv …

#define get_eflags …

#define set_eflags …

#endif /* HAVE_INLINE_ASM */

#if ARCH_X86_64

#define cpuid_test() …

#elif HAVE_X86ASM

#define cpuid_test …

#elif HAVE_INLINE_ASM

static int cpuid_test(void)
{
    x86_reg a, c;

    /* Check if CPUID is supported by attempting to toggle the ID bit in
     * the EFLAGS register. */
    get_eflags(a);
    set_eflags(a ^ 0x200000);
    get_eflags(c);

    return a != c;
}
#endif

/* Function to test if multimedia instructions are supported...  */
int ff_get_cpu_flags_x86(void)
{ … }

size_t ff_get_cpu_max_align_x86(void)
{ … }