FFmpeg/libavutil/bswap.h
Rémi Denis-Courmont df2057041b lavu/riscv: byte-swap operations
If the target supports the Basic bit-manipulation (Zbb) extension, then
the REV8 instruction is available to reverse byte order.

Note that this instruction only exists at the "XLEN" register size,
so we need to right shift the result down to the data width.

If Zbb is not supported, then this patchset does nothing. Support for
run-time detection is left for the future. Currently, there are no
bits in auxv/ELF HWCAP for Z-extensions, so there are no clean ways to
do this.
2022-09-13 16:50:43 -03:00

112 lines
2.8 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_AARCH64
# include "aarch64/bswap.h"
#elif ARCH_ARM
# include "arm/bswap.h"
#elif ARCH_AVR32
# include "avr32/bswap.h"
#elif ARCH_RISCV
# include "riscv/bswap.h"
#elif ARCH_SH4
# include "sh4/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 */