From: W. Felix Handte <w@felixhandte.com>
Date: Wed, 18 Aug 2021 20:02:01 +0000 (-0400)
Subject: Give Up on Searching End of Block
X-Git-Tag: v1.5.1~1^2~116^2~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7c24c3e6ce8faa5a6d23ef9d11c71a0a106b3bb3;p=thirdparty%2Fzstd.git

Give Up on Searching End of Block

Amusingly, it seems to be a non-trivial performance hit to add in final
searches or even hash table insertions during cleanup. So let's not. It seems
to not make any meaningful difference in compression ratio.
---

diff --git a/lib/compress/zstd_fast.c b/lib/compress/zstd_fast.c
index f7df66681..50bceef74 100644
--- a/lib/compress/zstd_fast.c
+++ b/lib/compress/zstd_fast.c
@@ -354,10 +354,9 @@ _start: /* Requires: ip0 */
     } while (ip2 < ilimit);
 
 _cleanup:
-
-    /* Find matches at end of block. */
-
-    /* TODO */
+    /* Note that there are probably still a couple positions we could search.
+     * However, it seems to be a meaningful performance hit to try to search
+     * them. So let's not. */
 
     /* save reps for next block */
     rep[0] = rep_offset1 ? rep_offset1 : offsetSaved;