From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 26 Sep 2024 00:42:13 +0000 (-0700)
Subject: factor: tweak gcd_odd performance
X-Git-Tag: v9.6~161
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9cc3e786e61fd9a3604beaf1b882e5c31a8592d1;p=thirdparty%2Fcoreutils.git

factor: tweak gcd_odd performance

* src/factor.c (gcd_odd): Use stdc_trailing_zeros instead of
counting zeros by hand.
---

diff --git a/src/factor.c b/src/factor.c
index 0e9e703df4..13fb92f8de 100644
--- a/src/factor.c
+++ b/src/factor.c
@@ -413,8 +413,8 @@ gcd_odd (uintmax_t a, uintmax_t b)
       uintmax_t t;
       uintmax_t bgta;
 
-      while ((a & 1) == 0)
-        a >>= 1;
+      assume (a);
+      a >>= stdc_trailing_zeros (a);
       a >>= 1;
 
       t = a - b;