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/* Unaligned memory access functionality.
Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Red Hat, Inc.
Written by Ulrich Drepper <drepper@redhat.com>, 2001.
This program is Open Source software; you can redistribute it and/or
modify it under the terms of the Open Software License version 1.0 as
published by the Open Source Initiative.
You should have received a copy of the Open Software License along
with this program; if not, you may obtain a copy of the Open Software
License version 1.0 from http://www.opensource.org/licenses/osl.php or
by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
3001 King Ranch Road, Ukiah, CA 95482. */
#ifndef _MEMORY_ACCESS_H
#define _MEMORY_ACCESS_H 1
#include <byteswap.h>
#include <endian.h>
#include <limits.h>
#include <stdint.h>
/* When loading this file we require the macro MACHINE_ENCODING to be
defined to signal the endianness of the architecture which is
defined. */
#ifndef MACHINE_ENCODING
# error "MACHINE_ENCODING needs to be defined"
#endif
#if MACHINE_ENCODING != __BIG_ENDIAN && MACHINE_ENCODING != __LITTLE_ENDIAN
# error "MACHINE_ENCODING must signal either big or little endian"
#endif
/* We use simple memory access functions in case the hardware allows it.
The caller has to make sure we don't have alias problems. */
#if ALLOW_UNALIGNED
# define read_2ubyte_unaligned(Addr) \
(unlikely (MACHINE_ENCODING != __BYTE_ORDER) \
? bswap_16 (*((const uint16_t *) (Addr))) \
: *((const uint16_t *) (Addr)))
# define read_2sbyte_unaligned(Addr) \
(unlikely (MACHINE_ENCODING != __BYTE_ORDER) \
? (int16_t) bswap_16 (*((const int16_t *) (Addr))) \
: *((const int16_t *) (Addr)))
# define read_4ubyte_unaligned_noncvt(Addr) \
*((const uint32_t *) (Addr))
# define read_4ubyte_unaligned(Addr) \
(unlikely (MACHINE_ENCODING != __BYTE_ORDER) \
? bswap_32 (*((const uint32_t *) (Addr))) \
: *((const uint32_t *) (Addr)))
# define read_4sbyte_unaligned(Addr) \
(unlikely (MACHINE_ENCODING != __BYTE_ORDER) \
? (int32_t) bswap_32 (*((const int32_t *) (Addr))) \
: *((const int32_t *) (Addr)))
# define read_8ubyte_unaligned(Addr) \
(unlikely (MACHINE_ENCODING != __BYTE_ORDER) \
? bswap_64 (*((const uint64_t *) (Addr))) \
: *((const uint64_t *) (Addr)))
# define read_8sbyte_unaligned(Addr) \
(unlikely (MACHINE_ENCODING != __BYTE_ORDER) \
? (int64_t) bswap_64 (*((const int64_t *) (Addr))) \
: *((const int64_t *) (Addr)))
#else
union unaligned
{
void *p;
uint16_t u2;
uint32_t u4;
uint64_t u8;
int16_t s2;
int32_t s4;
int64_t s8;
} __attribute__ ((packed));
static inline uint16_t
read_2ubyte_unaligned (const void *p)
{
const union unaligned *up = p;
if (MACHINE_ENCODING != __BYTE_ORDER)
return bswap_16 (up->u2);
return up->u2;
}
static inline int16_t
read_2sbyte_unaligned (const void *p)
{
const union unaligned *up = p;
if (MACHINE_ENCODING != __BYTE_ORDER)
return (int16_t) bswap_16 (up->u2);
return up->s2;
}
static inline uint32_t
read_4ubyte_unaligned_noncvt (const void *p)
{
const union unaligned *up = p;
return up->u4;
}
static inline uint32_t
read_4ubyte_unaligned (const void *p)
{
const union unaligned *up = p;
if (MACHINE_ENCODING != __BYTE_ORDER)
return bswap_32 (up->u4);
return up->u4;
}
static inline int32_t
read_4sbyte_unaligned (const void *p)
{
const union unaligned *up = p;
if (MACHINE_ENCODING != __BYTE_ORDER)
return (int32_t) bswap_32 (up->u4);
return up->s4;
}
static inline uint64_t
read_8ubyte_unaligned (const void *p)
{
const union unaligned *up = p;
if (MACHINE_ENCODING != __BYTE_ORDER)
return bswap_64 (up->u8);
return up->u8;
}
static inline int64_t
read_8sbyte_unaligned (const void *p)
{
const union unaligned *up = p;
if (MACHINE_ENCODING != __BYTE_ORDER)
return (int64_t) bswap_64 (up->u8);
return up->s8;
}
#endif /* allow unaligned */
#define read_2ubyte_unaligned_inc(Addr) \
({ uint16_t t_ = read_2ubyte_unaligned (Addr); \
Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \
t_; })
#define read_2sbyte_unaligned_inc(Addr) \
({ int16_t t_ = read_2sbyte_unaligned (Addr); \
Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \
t_; })
#define read_4ubyte_unaligned_inc(Addr) \
({ uint32_t t_ = read_4ubyte_unaligned (Addr); \
Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \
t_; })
#define read_4sbyte_unaligned_inc(Addr) \
({ int32_t t_ = read_4sbyte_unaligned (Addr); \
Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 4); \
t_; })
#define read_8ubyte_unaligned_inc(Addr) \
({ uint64_t t_ = read_8ubyte_unaligned (Addr); \
Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \
t_; })
#define read_8sbyte_unaligned_inc(Addr) \
({ int64_t t_ = read_8sbyte_unaligned (Addr); \
Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 8); \
t_; })
#endif /* memory-access.h */
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