bits manipulation

[sadon]

Hi all

I used this code to switch bit4 with bit0

 a0=a & 0x01;
 a4=a & 0x10;
 aa=a & 0xEE;
 e=aa |(a0<<4)|(a4>>4);

it is ok but a kind of long if i want to switch more bits! I believe that there is an easier way of doing it

any help !!!


thanks alot

[helios]

Nope. That's the shortest possible.
It can be made more generic, though:

unsigned swapBits(unsigned x,unsigned bita,unsigned bitb){
	//bita is assumend to be <=bitb
	unsigned maska=1<<bita,
		maskb=1<<bitb,
		maskx=~(maska|maskb);
	return ((x&maska)<<(bitb-bita))|((x&maskb)>>(bitb-bita))|(x&maskx);
}