Openmp critical section inside if conditional statement

Question

I have a function like this

void foo(x, *y) {
    some calculations

    if (x > *y) {
        *y = x/2;
    }

    more calculations
}

My parallel section is

int x[] = some array;
double y=0;
#pragma omp parallel for
for ( int i  = 0; i<=n; i++) {
    do something 
    for ( int j = 0; j<=n; j++) {
           foo(x[i], &y);
}

If I rewrite the if statement as

*y = x > *y ? x/2 : *y;

I can do

#pragma omp critical
*y = x > *y ? x/2 : *y;

But I don’t want to change the code. How do I create a critical section for the conditional y-update block?