Advent of code, day 15, golfed C

#include <stdio.h>
#define l long
#define r return
#define w while
#define E(G) r G & 0xffff;
#define M(N) N##000000
typedef l (*f)();
#define GU(G,A,M) l G; l u_##G(){G=(G*A)%2147483647;E(G)}\
    l u_##G##2 (){do u_##G(); w(G%M);E(G)}
GU(a,16807,4) GU(b,48271,8)
void j(l m, f ua, f ub){a=512;b=191;l c=0; w(m-->0) c+=ua()==ub();
    printf("%ld\n", c);}
int main(){j(M(40),u_a,u_b); j(M(5),u_a2,u_b2); r 0;}