cpu.h 2.83 KB
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/*****************************************************************************
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 * cpu.h: cpu detection
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 *****************************************************************************
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 * Copyright (C) 2004-2019 x264 project
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 *
 * Authors: Loren Merritt <lorenm@u.washington.edu>
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 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
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 *
 * This program is also available under a commercial proprietary license.
 * For more information, contact us at licensing@x264.com.
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 *****************************************************************************/

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#ifndef X264_CPU_H
#define X264_CPU_H
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uint32_t x264_cpu_detect( void );
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int      x264_cpu_num_processors( void );
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void     x264_cpu_emms( void );
void     x264_cpu_sfence( void );
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#if HAVE_MMX
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/* There is no way to forbid the compiler from using float instructions
 * before the emms so miscompilation could theoretically occur in the
 * unlikely event that the compiler reorders emms and float instructions. */
#if HAVE_X86_INLINE_ASM
/* Clobbering memory makes the compiler less likely to reorder code. */
#define x264_emms() asm volatile( "emms":::"memory","st","st(1)","st(2)", \
                                  "st(3)","st(4)","st(5)","st(6)","st(7)" )
#else
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#define x264_emms() x264_cpu_emms()
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#endif
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#else
#define x264_emms()
#endif
#define x264_sfence x264_cpu_sfence
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/* kludge:
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 * gcc can't give variables any greater alignment than the stack frame has.
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 * We need 32 byte alignment for AVX2, so here we make sure that the stack is
 * aligned to 32 bytes.
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 * gcc 4.2 introduced __attribute__((force_align_arg_pointer)) to fix this
 * problem, but I don't want to require such a new version.
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 * aligning to 32 bytes only works if the compiler supports keeping that
 * alignment between functions (osdep.h handles manual alignment of arrays
 * if it doesn't).
 */
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#if HAVE_MMX && (STACK_ALIGNMENT > 16 || (ARCH_X86 && STACK_ALIGNMENT > 4))
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intptr_t x264_stack_align( void (*func)(), ... );
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#define x264_stack_align(func,...) x264_stack_align((void (*)())func, __VA_ARGS__)
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#else
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#define x264_stack_align(func,...) func(__VA_ARGS__)
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#endif

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typedef struct
{
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    const char *name;
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    uint32_t flags;
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} x264_cpu_name_t;
extern const x264_cpu_name_t x264_cpu_names[];
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#endif