gmio/src/c/endian.c

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#include "endian.h"
foug_endianness_t foug_host_endianness()
{
union {
uint32_t integer;
uint8_t bytes[4];
} u;
u.integer = 0x01020408;
if (u.bytes[0] == 0x08 && u.bytes[3] == 0x01)
return FOUG_LITTLE_ENDIAN;
else if (u.bytes[0] == 0x01 && u.bytes[3] == 0x08)
return FOUG_BIG_ENDIAN;
else if (u.bytes[1] == 0x08 && u.bytes[2] == 0x01)
return FOUG_MIDDLE_ENDIAN;
else
return FOUG_OTHER_ENDIAN;
}
uint16_t foug_uint16_swap(uint16_t val)
{
return ((val & 0x00FF) << 8) | ((val >> 8) & 0x00FF);
}
uint16_t foug_uint16_noswap(uint16_t val)
{
return val;
}
uint16_t foug_decode_uint16_le(const uint8_t* bytes)
{
/* |0 |1 | */
/* |BB|AA| -> 0xAABB */
return (bytes[1] << 8) | bytes[0];
}
uint16_t foug_decode_uint16_be(const uint8_t* bytes)
{
/* |0 |1 | */
/* |AA|BB| -> 0xAABB */
return (bytes[0] << 8) | bytes[1];
}
uint32_t foug_uint32_swap(uint32_t val)
{
return
((val & 0x000000FF) << 24)
| ((val & 0x0000FF00) << 8)
| ((val >> 8) & 0x0000FF00)
| ((val >> 24) & 0x000000FF);
}
uint32_t foug_uint32_noswap(uint32_t val)
{
return val;
}
uint32_t foug_decode_uint32_le(const uint8_t* bytes)
{
/* |DD|CC|BB|AA| -> 0xAABBCCDD */
return bytes[0] | (bytes[1] << 8) | (bytes[2] << 16) | (bytes[3] << 24);
}
uint32_t foug_decode_uint32_me(const uint8_t* bytes)
{
/* |DD|CC|BB|AA| -> 0xCCDDAABB */
return (bytes[0] >> 8) | (bytes[2] << 8) | (bytes[3] << 8) | (bytes[8] << 8);
}
uint32_t foug_decode_uint32_be(const uint8_t* bytes)
{
/* |DD|CC|BB|AA| -> 0xDDCCBBAA */
return bytes[3] | (bytes[2] << 8) | (bytes[1] << 16) | (bytes[0] << 24);
}
static foug_real32_t convert_real32(uint32_t val)
{
union
{
uint32_t as_integer;
foug_real32_t as_float;
} u;
u.as_integer = val;
return u.as_float;
}
foug_real32_t foug_decode_real32_le(const uint8_t* bytes)
{
return convert_real32(foug_decode_uint32_le(bytes));
}
foug_real32_t foug_decode_real32_me(const uint8_t* bytes)
{
return convert_real32(foug_decode_uint32_me(bytes));
}
foug_real32_t foug_decode_real32_be(const uint8_t* bytes)
{
return convert_real32(foug_decode_uint32_be(bytes));
}