for(i=0;i<8;i++) { tmp1 = block[1]; tmp2 = block[2]; tmp3 = block[3]; tmp4 = block[4]; tmp5 = block[5]; tmp6 = block[6]; block[1] = tmp2; block[2] = tmp4; block[3] = tmp6; block[4] = tmp1; block[5] = tmp3; block[6] = tmp5; block += 8; }
for(i=0; i<64; i++) temp[ permutation[i] ] = block[i];  for(i=0; i<64; i++) block[i] = temp[i];
void block_permute(INT16 *block){    int tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;    int i;    for(i=0;i<8;i++) {        tmp1 = block[1];        tmp2 = block[2];        tmp3 = block[3];        tmp4 = block[4];        tmp5 = block[5];        tmp6 = block[6];        block[1] = tmp2;        block[2] = tmp4;        block[3] = tmp6;        block[4] = tmp1;        block[5] = tmp3;        block[6] = tmp5;        block += 8;    }}