From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 25 May 2022 18:23:39 +0000 (-0700)
Subject: sort: tune diff_reversed
X-Git-Tag: v9.2~188
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9104dad18b1d2587f475baea1b32ebd51bf0d6f6;p=thirdparty%2Fcoreutils.git

sort: tune diff_reversed

* src/sort.c (diff_reversed): Tune.  On x86-64 with GCC, this
saves a conditional branch and shortens the generated machine code.
---

diff --git a/src/sort.c b/src/sort.c
index 0cd22f9313..0a6b557ac9 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -2607,7 +2607,7 @@ key_warnings (struct keyfield const *gkey, bool gkey_only)
 static int
 diff_reversed (int diff, bool reversed)
 {
-  return reversed ? (diff < 0 ? 1 : -diff) : diff;
+  return reversed ? (diff < 0) - (diff > 0) : diff;
 }
 
 /* Compare two lines A and B trying every key in sequence until there