parity in C

int oparity(int val)
{
    int parity = 0;

    while(val)
    {
        parity = !parity;
        val &= val-1;
        //val = val&(val-1);
        //val &= ~(val&-val);
        //val ^= val&(~val+1);
    }

    return parity;
}

int oparity(int val)
{
    int nbit = 0;

    while(val)
    {
        if(val&1) nbit++;
        val >>= 1;
    }

    return nbit%2;
}

-----------------oddparity.c-----------------
#include <stdio.h>

int oparity(int val)
{
    int nbit = 0;

    while(val)
    {
        if(val&1) nbit++;
        val >>= 1;
    }

    return nbit%2;
}

int main()
{
    int val = 0xaF19;

    printf("oddparity of 0x%X is %d\n", val, oparity(val));
    printf("evenparity of 0x%X is %d\n", val, oparity(val)?0:1);

    return 0;
}
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Reference:
http://resnet.uoregon.edu/~gurney_j/jmpc/bitwise.html