Restrict global and function references to memory size

gen/rand.go

@@ -9,6 +9,16 @@ func RandBiasedUint64() uint64 {
 	return (rand.Uint64() | 0x8000000000000000) >> rand.Intn(65)
 }
 
+// Like RandBiasedUint64() but always returns < n
+func RandBiasedUint64n(n uint64) uint64 {
+	for {
+		ret := RandBiasedUint64()
+		if ret < n {
+			return ret
+		}
+	}
+}
+
 // Generate a random int64 with an even distribution of the tuple
 // {sign, bits.Len64(math.Abs())}
 func RandBiasedInt64() uint64 {