From 418fd6175952c4147de24407d224b140c843b619 Mon Sep 17 00:00:00 2001
From: nicoo <nicoo@debian.org>
Date: Sun, 24 May 2020 15:41:23 +0200
Subject: [PATCH] factor::factor: Short-circuit the fallback to Pollard's rho

When the remainder is smaller than the max. entry in the table,
it is guaranteed to be prime.
---
 src/uu/factor/src/factor.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/uu/factor/src/factor.rs b/src/uu/factor/src/factor.rs
index 894c61c81..1e5b3bb8f 100644
--- a/src/uu/factor/src/factor.rs
+++ b/src/uu/factor/src/factor.rs
@@ -100,7 +100,11 @@ fn factor(mut n: u64) -> Factors {
 
     let (f, n) = table::factor(n);
     factors *= f;
-    factors *= rho::factor(n);
+
+    if n >= table::NEXT_PRIME {
+        factors *= rho::factor(n);
+    }
+
     factors
 }