From 83b5e4a5611654804c69190eeab6c2586993a954 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=A1s=20Ortega=20Froysa?= <nicolas@ortegas.org>
Date: Thu, 11 Dec 2025 06:34:42 +0100
Subject: [PATCH] Limit known-prime multiples marking until sqrt(end).

---
 src/worker.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/worker.rs b/src/worker.rs
index 886bb87..9ee1bfc 100644
--- a/src/worker.rs
+++ b/src/worker.rs
@@ -28,8 +28,14 @@ pub fn work_segment(known_primes:&Vec<u64>, start:usize, end:usize) -> Vec<u64>
 	let mut sieve = vec![true; end - start];
 	let mut found_primes = Vec::new();
 
+	let sqrt_end = f64::sqrt(end as f64) as usize;
+
 	for p in known_primes {
 		let prime = *p as usize;
+		if prime > sqrt_end {
+			break;
+		}
+
 		let modu = start % prime;
 		let mut mult = if modu == 0 {
 			start