8.1.10 Nibble and Byte Swapping

Other special cases of the bit-shift operations are nibble or byte swapping, SDCC recognizes the following expressions:

unsigned  char i;  
unsigned  int j;  
...  
i = ((i << 4) | (i >> 4));
j = ((j << 8) | (j >> 8));

and generates a swap instruction for the nibble swapping or move instructions for the byte swapping. The ''j'' example can be used to convert from little to big-endian or vice versa. If you want to change the endianness of a signed integer you have to cast to (unsigned int) first.

Note that SDCC stores numbers in little-endian^8.1 format (i.e. lowest order first).