ffmpeg/libavutil/arm/bswap.h
Måns Rullgård ac73f1a816 ARM: change argument/return type of bswap_16() to unsigned 32-bit
This avoids unnecessary masking otherwise added by the compilers.

Originally committed as revision 21953 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-02-22 00:34:08 +00:00

73 lines
1.8 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_ARM_BSWAP_H
#define AVUTIL_ARM_BSWAP_H
#include <stdint.h>
#include "config.h"
#include "libavutil/common.h"
#ifdef __ARMCC_VERSION
#if HAVE_ARMV6
#define bswap_16 bswap_16
static av_always_inline av_const unsigned bswap_16(unsigned x)
{
__asm { rev16 x, x }
return x;
}
#define bswap_32 bswap_32
static av_always_inline av_const uint32_t bswap_32(uint32_t x)
{
return __rev(x);
}
#endif /* HAVE_ARMV6 */
#elif HAVE_INLINE_ASM
#if HAVE_ARMV6
#define bswap_16 bswap_16
static av_always_inline av_const unsigned bswap_16(unsigned x)
{
__asm__("rev16 %0, %0" : "+r"(x));
return x;
}
#endif
#define bswap_32 bswap_32
static av_always_inline av_const uint32_t bswap_32(uint32_t x)
{
#if HAVE_ARMV6
__asm__("rev %0, %0" : "+r"(x));
#else
uint32_t t;
__asm__ ("eor %1, %0, %0, ror #16 \n\t"
"bic %1, %1, #0xFF0000 \n\t"
"mov %0, %0, ror #8 \n\t"
"eor %0, %0, %1, lsr #8 \n\t"
: "+r"(x), "=&r"(t));
#endif /* HAVE_ARMV6 */
return x;
}
#endif /* __ARMCC_VERSION */
#endif /* AVUTIL_ARM_BSWAP_H */