ffmpeg/libavutil/intreadwrite.h
Måns Rullgård 3c55ce039d ARM asm for AV_RN*()
ARMv6 and later support unaligned loads and stores for single
word/halfword but not double/multiple.  GCC is ignorant of this and
will always use bytewise accesses for unaligned data.  Casting to an
int32_t pointer is dangerous since a load/store double or multiple
instruction might be used (this happens with some code in FFmpeg).
Implementing the AV_[RW]* macros with inline asm using only supported
instructions gives fast and safe unaligned accesses.  ARM RVCT does
the right thing with generic code.

This gives an overall speedup of up to 10%.

Originally committed as revision 18601 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-04-18 00:00:28 +00:00

265 lines
8.0 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
*/
#ifndef AVUTIL_INTREADWRITE_H
#define AVUTIL_INTREADWRITE_H
#include <stdint.h>
#include "config.h"
#include "bswap.h"
/*
* Arch-specific headers can provide any combination of
* AV_[RW][BLN](16|32|64) macros. Preprocessor symbols must be
* defined, even if these are implemented as inline functions.
*/
#if ARCH_ARM
# include "arm/intreadwrite.h"
#endif
/*
* Define AV_[RW]N helper macros to simplify definitions not provided
* by per-arch headers.
*/
#if defined(__GNUC__)
struct unaligned_64 { uint64_t l; } __attribute__((packed));
struct unaligned_32 { uint32_t l; } __attribute__((packed));
struct unaligned_16 { uint16_t l; } __attribute__((packed));
# define AV_RN(s, p) (((const struct unaligned_##s *) (p))->l)
# define AV_WN(s, p, v) (((struct unaligned_##s *) (p))->l) = (v)
#elif defined(__DECC)
# define AV_RN(s, p) (*((const __unaligned uint##s##_t*)(p)))
# define AV_WN(s, p, v) *((__unaligned uint##s##_t*)(p)) = (v)
#elif HAVE_FAST_UNALIGNED
# define AV_RN(s, p) (*((const uint##s##_t*)(p)))
# define AV_WN(s, p, v) *((uint##s##_t*)(p)) = (v)
#else
#ifndef AV_RB16
#define AV_RB16(x) ((((const uint8_t*)(x))[0] << 8) | \
((const uint8_t*)(x))[1])
#endif
#ifndef AV_WB16
#define AV_WB16(p, d) do { \
((uint8_t*)(p))[1] = (d); \
((uint8_t*)(p))[0] = (d)>>8; } while(0)
#endif
#ifndef AV_RL16
#define AV_RL16(x) ((((const uint8_t*)(x))[1] << 8) | \
((const uint8_t*)(x))[0])
#endif
#ifndef AV_WL16
#define AV_WL16(p, d) do { \
((uint8_t*)(p))[0] = (d); \
((uint8_t*)(p))[1] = (d)>>8; } while(0)
#endif
#ifndef AV_RB32
#define AV_RB32(x) ((((const uint8_t*)(x))[0] << 24) | \
(((const uint8_t*)(x))[1] << 16) | \
(((const uint8_t*)(x))[2] << 8) | \
((const uint8_t*)(x))[3])
#endif
#ifndef AV_WB32
#define AV_WB32(p, d) do { \
((uint8_t*)(p))[3] = (d); \
((uint8_t*)(p))[2] = (d)>>8; \
((uint8_t*)(p))[1] = (d)>>16; \
((uint8_t*)(p))[0] = (d)>>24; } while(0)
#endif
#ifndef AV_RL32
#define AV_RL32(x) ((((const uint8_t*)(x))[3] << 24) | \
(((const uint8_t*)(x))[2] << 16) | \
(((const uint8_t*)(x))[1] << 8) | \
((const uint8_t*)(x))[0])
#endif
#ifndef AV_WL32
#define AV_WL32(p, d) do { \
((uint8_t*)(p))[0] = (d); \
((uint8_t*)(p))[1] = (d)>>8; \
((uint8_t*)(p))[2] = (d)>>16; \
((uint8_t*)(p))[3] = (d)>>24; } while(0)
#endif
#ifndef AV_RB64
#define AV_RB64(x) (((uint64_t)((const uint8_t*)(x))[0] << 56) | \
((uint64_t)((const uint8_t*)(x))[1] << 48) | \
((uint64_t)((const uint8_t*)(x))[2] << 40) | \
((uint64_t)((const uint8_t*)(x))[3] << 32) | \
((uint64_t)((const uint8_t*)(x))[4] << 24) | \
((uint64_t)((const uint8_t*)(x))[5] << 16) | \
((uint64_t)((const uint8_t*)(x))[6] << 8) | \
(uint64_t)((const uint8_t*)(x))[7])
#endif
#ifndef AV_WB64
#define AV_WB64(p, d) do { \
((uint8_t*)(p))[7] = (d); \
((uint8_t*)(p))[6] = (d)>>8; \
((uint8_t*)(p))[5] = (d)>>16; \
((uint8_t*)(p))[4] = (d)>>24; \
((uint8_t*)(p))[3] = (d)>>32; \
((uint8_t*)(p))[2] = (d)>>40; \
((uint8_t*)(p))[1] = (d)>>48; \
((uint8_t*)(p))[0] = (d)>>56; } while(0)
#endif
#ifndef AV_RL64
#define AV_RL64(x) (((uint64_t)((const uint8_t*)(x))[7] << 56) | \
((uint64_t)((const uint8_t*)(x))[6] << 48) | \
((uint64_t)((const uint8_t*)(x))[5] << 40) | \
((uint64_t)((const uint8_t*)(x))[4] << 32) | \
((uint64_t)((const uint8_t*)(x))[3] << 24) | \
((uint64_t)((const uint8_t*)(x))[2] << 16) | \
((uint64_t)((const uint8_t*)(x))[1] << 8) | \
(uint64_t)((const uint8_t*)(x))[0])
#endif
#ifndef AV_WL64
#define AV_WL64(p, d) do { \
((uint8_t*)(p))[0] = (d); \
((uint8_t*)(p))[1] = (d)>>8; \
((uint8_t*)(p))[2] = (d)>>16; \
((uint8_t*)(p))[3] = (d)>>24; \
((uint8_t*)(p))[4] = (d)>>32; \
((uint8_t*)(p))[5] = (d)>>40; \
((uint8_t*)(p))[6] = (d)>>48; \
((uint8_t*)(p))[7] = (d)>>56; } while(0)
#endif
#ifdef WORDS_BIGENDIAN
# define AV_RN(s, p) AV_RB##s(p)
# define AV_WN(s, p, v) AV_WB##s(p, v)
#else
# define AV_RN(s, p) AV_RL##s(p)
# define AV_WN(s, p, v) AV_WL##s(p, v)
#endif
#endif /* HAVE_FAST_UNALIGNED */
#ifndef AV_RN16
# define AV_RN16(p) AV_RN(16, p)
#endif
#ifndef AV_RN32
# define AV_RN32(p) AV_RN(32, p)
#endif
#ifndef AV_RN64
# define AV_RN64(p) AV_RN(64, p)
#endif
#ifndef AV_WN16
# define AV_WN16(p, v) AV_WN(16, p, v)
#endif
#ifndef AV_WN32
# define AV_WN32(p, v) AV_WN(32, p, v)
#endif
#ifndef AV_WN64
# define AV_WN64(p, v) AV_WN(64, p, v)
#endif
#ifdef WORDS_BIGENDIAN
# define AV_RB(s, p) AV_RN(s, p)
# define AV_WB(s, p, v) AV_WN(s, p, v)
# define AV_RL(s, p) bswap_##s(AV_RN(s, p))
# define AV_WL(s, p, v) AV_WN(s, p, bswap_##s(v))
#else
# define AV_RB(s, p) bswap_##s(AV_RN(s, p))
# define AV_WB(s, p, v) AV_WN(s, p, bswap_##s(v))
# define AV_RL(s, p) AV_RN(s, p)
# define AV_WL(s, p, v) AV_WN(s, p, v)
#endif
#define AV_RB8(x) (((const uint8_t*)(x))[0])
#define AV_WB8(p, d) do { ((uint8_t*)(p))[0] = (d); } while(0)
#define AV_RL8(x) AV_RB8(x)
#define AV_WL8(p, d) AV_WB8(p, d)
#ifndef AV_RB16
# define AV_RB16(p) AV_RB(16, p)
#endif
#ifndef AV_WB16
# define AV_WB16(p, v) AV_WB(16, p, v)
#endif
#ifndef AV_RL16
# define AV_RL16(p) AV_RL(16, p)
#endif
#ifndef AV_WL16
# define AV_WL16(p, v) AV_WL(16, p, v)
#endif
#ifndef AV_RB32
# define AV_RB32(p) AV_RB(32, p)
#endif
#ifndef AV_WB32
# define AV_WB32(p, v) AV_WB(32, p, v)
#endif
#ifndef AV_RL32
# define AV_RL32(p) AV_RL(32, p)
#endif
#ifndef AV_WL32
# define AV_WL32(p, v) AV_WL(32, p, v)
#endif
#ifndef AV_RB64
# define AV_RB64(p) AV_RB(64, p)
#endif
#ifndef AV_WB64
# define AV_WB64(p, v) AV_WB(64, p, v)
#endif
#ifndef AV_RL64
# define AV_RL64(p) AV_RL(64, p)
#endif
#ifndef AV_WL64
# define AV_WL64(p, v) AV_WL(64, p, v)
#endif
#define AV_RB24(x) ((((const uint8_t*)(x))[0] << 16) | \
(((const uint8_t*)(x))[1] << 8) | \
((const uint8_t*)(x))[2])
#define AV_WB24(p, d) do { \
((uint8_t*)(p))[2] = (d); \
((uint8_t*)(p))[1] = (d)>>8; \
((uint8_t*)(p))[0] = (d)>>16; } while(0)
#define AV_RL24(x) ((((const uint8_t*)(x))[2] << 16) | \
(((const uint8_t*)(x))[1] << 8) | \
((const uint8_t*)(x))[0])
#define AV_WL24(p, d) do { \
((uint8_t*)(p))[0] = (d); \
((uint8_t*)(p))[1] = (d)>>8; \
((uint8_t*)(p))[2] = (d)>>16; } while(0)
#endif /* AVUTIL_INTREADWRITE_H */