OpenModem/bertos/cpu/byteorder.h
2014-04-03 22:21:37 +02:00

262 lines
7.4 KiB
C++

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*
* Copyright 2004 Develer S.r.l. (http://www.develer.com/)
* -->
*
* \brief Functions to convert integers to/from host byte-order.
*
* \author Bernie Innocenti <bernie@codewiz.org>
* \author Stefano Fedrigo <aleph@develer.com>
*/
#ifndef MWARE_BYTEORDER_H
#define MWARE_BYTEORDER_H
#include <cfg/compiler.h>
#include <cpu/attr.h>
#include <cpu/detect.h>
#include <cpu/types.h>
#include <cfg/macros.h>
/**
* Swap upper and lower bytes in a 16-bit value.
*/
#define SWAB16(x) ((uint16_t)(ROTR((x), 8) + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
/*
* On Cortex-M3, GCC 4.4 builtin implementation is slower than our own
* rot-based implementation.
*/
#if GNUC_PREREQ(4, 3) && !CPU_CM3
#define SWAB32(x) ((uint32_t)(__builtin_bswap32((x) + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))))
#else
/**
* Reverse bytes in a 32-bit value (e.g.: 0x12345678 -> 0x78563412).
*/
#define SWAB32(x) ((uint32_t)(( \
(ROTR(x, 8) & 0xFF00FF00) | \
(ROTL(x, 8) & 0x00FF00FF))) + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t)))
#endif
#if GNUC_PREREQ(4, 3)
#define SWAB64(x) ((uint64_t)(__builtin_bswap64((x) + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t)))))
#else
/**
* Reverse bytes in a 64-bit value.
*/
#define SWAB64(x) ((uint64_t)( \
(((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
(((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
(((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
(((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \
(((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \
(((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
(((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
(((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56) + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
#endif
#if CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN
#define cpu_to_le16(x) ((uint16_t)(x + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
#define cpu_to_le32(x) ((uint32_t)(x + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
#define cpu_to_le64(x) ((uint64_t)(x + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
#define cpu_to_be16(x) SWAB16(x)
#define cpu_to_be32(x) SWAB32(x)
#define cpu_to_be64(x) SWAB64(x)
#elif CPU_BYTE_ORDER == CPU_BIG_ENDIAN
#define cpu_to_le16(x) SWAB16(x)
#define cpu_to_le32(x) SWAB32(x)
#define cpu_to_le64(x) SWAB64(x)
#define cpu_to_be16(x) ((uint16_t)(x + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint16_t))))
#define cpu_to_be32(x) ((uint32_t)(x + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint32_t))))
#define cpu_to_be64(x) ((uint64_t)(x + \
STATIC_ASSERT_EXPR(sizeof(x) == sizeof(uint64_t))))
#else
#error "unrecognized CPU endianness"
#endif
#define be16_to_cpu(x) cpu_to_be16(x)
#define le16_to_cpu(x) cpu_to_le16(x)
#define be32_to_cpu(x) cpu_to_be32(x)
#define le32_to_cpu(x) cpu_to_le32(x)
#define be64_to_cpu(x) cpu_to_be64(x)
#define le64_to_cpu(x) cpu_to_le64(x)
#define host_to_net16(x) cpu_to_be16(x)
#define net_to_host16(x) be16_to_cpu(x)
#define host_to_net32(x) cpu_to_be32(x)
#define net_to_host32(x) be32_to_cpu(x)
#define host_to_net64(x) cpu_to_be64(x)
#define net_to_host64(x) be64_to_cpu(x)
/**
* Reverse bytes in a float value.
*/
INLINE float swab_float(float x)
{
/* Avoid breaking strict aliasing rules. */
char *cx = (char *)(&x);
STATIC_ASSERT(sizeof(float) == 4);
#define BYTEORDER_SWAP(a, b) do { (a) ^= (b); (b) ^= (a); (a) ^= (b); } while(0)
BYTEORDER_SWAP(cx[0], cx[3]);
BYTEORDER_SWAP(cx[1], cx[2]);
#undef BYTEORDER_SWAP
return x;
}
INLINE float cpu_to_be_float(float x)
{
return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab_float(x) : x;
}
INLINE float cpu_to_le_float(float x)
{
return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab_float(x) : x;
}
INLINE float be_float_to_cpu(float x)
{
return cpu_to_be_float(x);
}
INLINE float le_float_to_cpu(float x)
{
return cpu_to_le_float(x);
}
INLINE float host_to_net_float(float x)
{
return cpu_to_be_float(x);
}
INLINE float net_to_host_float(float x)
{
return be_float_to_cpu(x);
}
#if CPU_ARM
INLINE cpu_atomic_t
cpu_atomic_xchg(volatile cpu_atomic_t *ptr, cpu_atomic_t val)
{
cpu_atomic_t ret;
asm volatile(
"swp %0, %1, [%2]"
: "=&r" (ret)
: "r" (val), "r" (ptr)
: "memory", "cc");
return ret;
}
#else /* CPU_ARM */
#include <cpu/irq.h>
INLINE cpu_atomic_t
cpu_atomic_xchg(volatile cpu_atomic_t *ptr, cpu_atomic_t val)
{
cpu_atomic_t ret;
ATOMIC(
ret = *ptr;
*ptr = val;
);
return ret;
}
#endif /* CPU_ARM */
#ifdef __cplusplus
/// Type generic byte swapping.
template<typename T>
INLINE T swab(T x);
template<> INLINE uint16_t swab(uint16_t x) { return SWAB16(x); }
template<> INLINE uint32_t swab(uint32_t x) { return SWAB32(x); }
template<> INLINE uint64_t swab(uint64_t x) { return SWAB64(x); }
template<> INLINE int16_t swab(int16_t x) { return static_cast<int16_t>(SWAB16(static_cast<uint16_t>(x))); }
template<> INLINE int32_t swab(int32_t x) { return static_cast<int32_t>(SWAB32(static_cast<uint32_t>(x))); }
template<> INLINE int64_t swab(int64_t x) { return static_cast<int64_t>(SWAB64(static_cast<uint64_t>(x))); }
template<> INLINE float swab(float x) { return swab_float(x); }
/// Type generic conversion from CPU byte order to big-endian byte order.
template<typename T>
INLINE T cpu_to_be(T x)
{
return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
}
/// Type generic conversion from CPU byte-order to little-endian.
template<typename T>
INLINE T cpu_to_le(T x)
{
return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
}
/// Type generic conversion from big endian byte-order to CPU byte order.
template<typename T>
INLINE T be_to_cpu(T x)
{
return cpu_to_be(x);
}
/// Type generic conversion from little-endian byte order to CPU byte order.
template<typename T>
INLINE T le_to_cpu(T x)
{
return cpu_to_le(x);
}
/// Type generic conversion from network byte order to host byte order.
template<typename T>
INLINE T net_to_host(T x)
{
return be_to_cpu(x);
}
/// Type generic conversion from host byte order to network byte order.
template<typename T>
INLINE T host_to_net(T x)
{
return net_to_host(x);
}
#endif /* __cplusplus */
#endif /* MWARE_BYTEORDER_H */