byteorder.h

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#ifndef MWARE_BYTEORDER_H
#define MWARE_BYTEORDER_H

#include <cfg/compiler.h>
#include <cpu/attr.h>

INLINE uint16_t swab16(uint16_t x)
{
    return    ((x & (uint16_t)0x00FFU) << 8)
        | ((x & (uint16_t)0xFF00U) >> 8);
}

INLINE uint32_t swab32(uint32_t x)
{
    return    ((x & (uint32_t)0x000000FFUL) << 24)
        | ((x & (uint32_t)0x0000FF00UL) <<  8)
        | ((x & (uint32_t)0x00FF0000UL) >>  8)
        | ((x & (uint32_t)0xFF000000UL) >> 24);
}

INLINE uint64_t swab64(uint64_t x)
{
    return (uint64_t)swab32(x >> 32)
        | ((uint64_t)swab32(x & 0xFFFFFFFFUL) << 32);
}

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) ((a) ^= (b) ^= (a) ^= (b))
    BYTEORDER_SWAP(cx[0], cx[3]);
    BYTEORDER_SWAP(cx[1], cx[2]);
    #undef BYTEORDER_SWAP
    return x;
}

INLINE uint16_t cpu_to_be16(uint16_t x)
{
    return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab16(x) : x;
}

INLINE uint16_t cpu_to_le16(uint16_t x)
{
    return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab16(x) : x;
}

INLINE uint32_t cpu_to_be32(uint32_t x)
{
    return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab32(x) : x;
}

INLINE uint32_t cpu_to_le32(uint32_t x)
{
    return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab32(x) : x;
}

INLINE uint64_t cpu_to_be64(uint64_t x)
{
    return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab64(x) : x;
}

INLINE uint64_t cpu_to_le64(uint64_t x)
{
    return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab64(x) : 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 uint16_t be16_to_cpu(uint16_t x)
{
    return cpu_to_be16(x);
}

INLINE uint16_t le16_to_cpu(uint16_t x)
{
    return cpu_to_le16(x);
}

INLINE uint32_t be32_to_cpu(uint32_t x)
{
    return cpu_to_be32(x);
}

INLINE uint32_t le32_to_cpu(uint32_t x)
{
    return cpu_to_le32(x);
}

INLINE uint64_t be64_to_cpu(uint64_t x)
{
    return cpu_to_be64(x);
}

INLINE uint64_t le64_to_cpu(uint64_t x)
{
    return cpu_to_le64(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 uint16_t host_to_net16(uint16_t x)
{
    return cpu_to_be16(x);
}

INLINE uint16_t net_to_host16(uint16_t x)
{
    return be16_to_cpu(x);
}

INLINE uint32_t host_to_net32(uint32_t x)
{
    return cpu_to_be32(x);
}

INLINE uint32_t net_to_host32(uint32_t x)
{
    return be32_to_cpu(x);
}

INLINE uint64_t host_to_net64(uint64_t x)
{
    return cpu_to_be64(x);
}

INLINE uint64_t net_to_host64(uint64_t x)
{
    return be64_to_cpu(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);
}

#ifdef __cplusplus

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); }

template<typename T>
INLINE T cpu_to_be(T x)
{
    return (CPU_BYTE_ORDER == CPU_LITTLE_ENDIAN) ? swab(x) : x;
}

template<typename T>
INLINE T cpu_to_le(T x)
{
    return (CPU_BYTE_ORDER == CPU_BIG_ENDIAN) ? swab(x) : x;
}

template<typename T>
INLINE T be_to_cpu(T x)
{
    return cpu_to_be(x);
}

template<typename T>
INLINE T le_to_cpu(T x)
{
    return cpu_to_le(x);
}

template<typename T>
INLINE T net_to_host(T x)
{
    return be_to_cpu(x);
}

template<typename T>
INLINE T host_to_net(T x)
{
    return net_to_host(x);
}

#endif /* __cplusplus */

#endif /* MWARE_BYTEORDER_H */