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FFmpeg/libavutil/arm/intreadwrite.h
Mans Rullgard ec9d2c15c1 ARM: use Q/R inline asm operand modifiers only if supported
Some compilers do not support the Q/R modifiers used to access
the low/high parts of a 64-bit register pair.  Check for this
and disable all uses of it when not supported.

Fixes bug #337.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2012-08-07 21:13:30 +01:00

92 lines
2.5 KiB
C

/*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_ARM_INTREADWRITE_H
#define AVUTIL_ARM_INTREADWRITE_H
#include <stdint.h>
#include "config.h"
#include "libavutil/attributes.h"
#if HAVE_FAST_UNALIGNED && HAVE_INLINE_ASM && !AV_GCC_VERSION_AT_LEAST(4,7)
#define AV_RN16 AV_RN16
static av_always_inline unsigned AV_RN16(const void *p)
{
const uint8_t *q = p;
unsigned v;
#if !AV_GCC_VERSION_AT_LEAST(4,6)
__asm__ ("ldrh %0, %1" : "=r"(v) : "m"(*(const uint16_t *)q));
#elif defined __thumb__
__asm__ ("ldrh %0, %1" : "=r"(v) : "m"(q[0]), "m"(q[1]));
#else
__asm__ ("ldrh %0, %1" : "=r"(v) : "Uq"(q[0]), "m"(q[1]));
#endif
return v;
}
#define AV_WN16 AV_WN16
static av_always_inline void AV_WN16(void *p, uint16_t v)
{
__asm__ ("strh %1, %0" : "=m"(*(uint16_t *)p) : "r"(v));
}
#define AV_RN32 AV_RN32
static av_always_inline uint32_t AV_RN32(const void *p)
{
const struct __attribute__((packed)) { uint32_t v; } *q = p;
uint32_t v;
__asm__ ("ldr %0, %1" : "=r"(v) : "m"(*q));
return v;
}
#define AV_WN32 AV_WN32
static av_always_inline void AV_WN32(void *p, uint32_t v)
{
__asm__ ("str %1, %0" : "=m"(*(uint32_t *)p) : "r"(v));
}
#if HAVE_ASM_MOD_Q
#define AV_RN64 AV_RN64
static av_always_inline uint64_t AV_RN64(const void *p)
{
const struct __attribute__((packed)) { uint32_t v; } *q = p;
uint64_t v;
__asm__ ("ldr %Q0, %1 \n\t"
"ldr %R0, %2 \n\t"
: "=&r"(v)
: "m"(q[0]), "m"(q[1]));
return v;
}
#define AV_WN64 AV_WN64
static av_always_inline void AV_WN64(void *p, uint64_t v)
{
__asm__ ("str %Q2, %0 \n\t"
"str %R2, %1 \n\t"
: "=m"(*(uint32_t*)p), "=m"(*((uint32_t*)p+1))
: "r"(v));
}
#endif /* HAVE_ASM_MOD_Q */
#endif /* HAVE_INLINE_ASM */
#endif /* AVUTIL_ARM_INTREADWRITE_H */