Reverse bits the easy way

typedef unsigned int uint;
uint reverse(uint val)
{
    int i;
    uint tval=0;

    for(i=0; i<sizeof(val)*8; i++)
    {
        tval <<= 1;
        tval |= val&1;
        val >>= 1;
    }

    return tval;
}

typedef unsigned int uint;
uint reverse(uint val)
{
    char i;
    uint tval=0;

    for(i=sizeof(val)*8; val; i--)
    {
        tval <<= 1;
        tval |= val&1;
        val >>= 1;
    }

    return (tval<<i);
}

Reference:
http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetNaive