#define CTL_BYTE_SWAP_32b_LIT(N) \ ((((N) & 0xFF) << 24) | \ (((N) & 0xFF00) << 8) | \ (((N) & 0xFF0000) >> 8) | \ (((N) & 0xFF000000) >> 24))
CTL_BYTE_SWAP_32b_LIT reverses the byte order of the four bytes of N and returns that value. You can use this macro to initialize a static variable with a byte-swapped constant.