ffmpeg/libavutil/x86/bswap.h
James Almer bd48764532 avutil/x86/bswap: force inline asm versions with ICC
Recent ICC versions that define GCC as >= 4.5 (like ICC 13) apparently can't
optimize the generic C versions of av_bswap*() on their own.

Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: James Almer <jamrial@gmail.com>
2015-07-18 20:48:09 -03:00

62 lines
1.6 KiB
C

/*
* 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
* byte swapping routines
*/
#ifndef AVUTIL_X86_BSWAP_H
#define AVUTIL_X86_BSWAP_H
#include <stdint.h>
#include "config.h"
#include "libavutil/attributes.h"
#if HAVE_INLINE_ASM
#if !AV_GCC_VERSION_AT_LEAST(4,1)
#define av_bswap16 av_bswap16
static av_always_inline av_const unsigned av_bswap16(unsigned x)
{
__asm__("rorw $8, %w0" : "+r"(x));
return x;
}
#endif /* !AV_GCC_VERSION_AT_LEAST(4,1) */
#if !AV_GCC_VERSION_AT_LEAST(4,5) || defined(__INTEL_COMPILER)
#define av_bswap32 av_bswap32
static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
{
__asm__("bswap %0" : "+r" (x));
return x;
}
#if ARCH_X86_64
#define av_bswap64 av_bswap64
static inline uint64_t av_const av_bswap64(uint64_t x)
{
__asm__("bswap %0": "=r" (x) : "0" (x));
return x;
}
#endif
#endif /* !AV_GCC_VERSION_AT_LEAST(4,5) */
#endif /* HAVE_INLINE_ASM */
#endif /* AVUTIL_X86_BSWAP_H */