minor fixes in perf test - OG perf measurement version

perf.cpp

@@ -1,14 +1,17 @@
 #include <cstdio>
 #include <cstdlib>
 #include <chrono>
+#include <cassert>
 #include "fastrand.h"
 
-#define N 9999999
-#define M 99999999
+#define N 10000000
+#define M 99999999 // M > N
 #define FROM 100
 #define TO 576
 
 int main() {
+	assert(M > N); // M > N
+
 	// Init
 	srand((unsigned int)time(NULL));
 	rand_state rs = init_rand();
@@ -54,14 +57,14 @@ int main() {
 	auto t4 = std::chrono::high_resolution_clock::now();
 
 	// lcg + modulo
-	for (int i = 0; i < N; ++i) {
+	for (int i = 0; i < M; ++i) {
 		sum += FROM + (lcg(&rs) % (TO - FROM));
 	}
 
 	auto t5 = std::chrono::high_resolution_clock::now();
 
 	// rand_between (also LCG, but no modulus)
-	for (int i = 0; i < N; ++i) {
+	for (int i = 0; i < M; ++i) {
 		sum += rand_between(&rs, FROM, TO);
 	}