Let's look at following C code snippet.
char buf[4];
int idx = any value;
char *a = buf[3 - idx];
char *b = buf[idx];
a and b are not aliased. As a result, if the offsets has form as below,
we can say it is not aliased.
offset1 = odd number - index;
offset2 = index;
Don't need { } here.