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FFmpeg/libavutil/bswap.h
Rémi Denis-Courmont c5f69719bc lavu/bswap: remove some inline assembler
C code or compiler built-ins are preferable over inline assembler for
byte-swaps as it allows for better optimisations (e.g. instruction
scheduling) which would otherwise be impossible.

As with f64c2e710f for x86 and Arm,
this removes the inline assembler on GCC (and Clang) since we now
require recent enough compiler versions. This indeed seems to work on
AArch64, SuperH and, if Zbb is enabled, RISC-V. (AVR32 was not tested
since it has no known working compilers at this time.)
2024-06-13 21:16:16 +03:00

106 lines
2.7 KiB
C

/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* 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_BSWAP_H
#define AVUTIL_BSWAP_H
#include <stdint.h>
#include "libavutil/avconfig.h"
#include "attributes.h"
#ifdef HAVE_AV_CONFIG_H
#include "config.h"
#if ARCH_ARM
# include "arm/bswap.h"
#elif ARCH_RISCV
# include "riscv/bswap.h"
#elif ARCH_X86
# include "x86/bswap.h"
#endif
#endif /* HAVE_AV_CONFIG_H */
#define AV_BSWAP16C(x) (((x) << 8 & 0xff00) | ((x) >> 8 & 0x00ff))
#define AV_BSWAP32C(x) (AV_BSWAP16C(x) << 16 | AV_BSWAP16C((x) >> 16))
#define AV_BSWAP64C(x) (AV_BSWAP32C(x) << 32 | AV_BSWAP32C((x) >> 32))
#define AV_BSWAPC(s, x) AV_BSWAP##s##C(x)
#ifndef av_bswap16
static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
{
x= (x>>8) | (x<<8);
return x;
}
#endif
#ifndef av_bswap32
static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
{
return AV_BSWAP32C(x);
}
#endif
#ifndef av_bswap64
static inline uint64_t av_const av_bswap64(uint64_t x)
{
return (uint64_t)av_bswap32(x) << 32 | av_bswap32(x >> 32);
}
#endif
// be2ne ... big-endian to native-endian
// le2ne ... little-endian to native-endian
#if AV_HAVE_BIGENDIAN
#define av_be2ne16(x) (x)
#define av_be2ne32(x) (x)
#define av_be2ne64(x) (x)
#define av_le2ne16(x) av_bswap16(x)
#define av_le2ne32(x) av_bswap32(x)
#define av_le2ne64(x) av_bswap64(x)
#define AV_BE2NEC(s, x) (x)
#define AV_LE2NEC(s, x) AV_BSWAPC(s, x)
#else
#define av_be2ne16(x) av_bswap16(x)
#define av_be2ne32(x) av_bswap32(x)
#define av_be2ne64(x) av_bswap64(x)
#define av_le2ne16(x) (x)
#define av_le2ne32(x) (x)
#define av_le2ne64(x) (x)
#define AV_BE2NEC(s, x) AV_BSWAPC(s, x)
#define AV_LE2NEC(s, x) (x)
#endif
#define AV_BE2NE16C(x) AV_BE2NEC(16, x)
#define AV_BE2NE32C(x) AV_BE2NEC(32, x)
#define AV_BE2NE64C(x) AV_BE2NEC(64, x)
#define AV_LE2NE16C(x) AV_LE2NEC(16, x)
#define AV_LE2NE32C(x) AV_LE2NEC(32, x)
#define AV_LE2NE64C(x) AV_LE2NEC(64, x)
#endif /* AVUTIL_BSWAP_H */