From: W. Felix Handte <w@felixhandte.com>
Date: Thu, 3 Sep 2020 17:34:38 +0000 (-0400)
Subject: Prefetch Chain Table Matches
X-Git-Tag: v1.4.7~80^2~14
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=20a020edbc7aac677552f273d1e9961c2a56d911;p=thirdparty%2Fzstd.git

Prefetch Chain Table Matches
---

diff --git a/lib/compress/zstd_lazy.c b/lib/compress/zstd_lazy.c
index f2de622d8..0b70494fa 100644
--- a/lib/compress/zstd_lazy.c
+++ b/lib/compress/zstd_lazy.c
@@ -653,9 +653,13 @@ size_t ZSTD_HcFindBestMatch_generic (
             U32 const chainLength = chainPackedPointer & 0xFF;
             U32 const chainAttempts = nbAttempts - ddsAttempt;
             U32 const chainLimit = chainAttempts > chainLength ? chainLength : chainAttempts;
-            U32 chainAttempt = 0;
+            U32 chainAttempt;
 
-            for ( ; chainAttempt < chainLimit; chainAttempt++, chainIndex++) {
+            for (chainAttempt = 0 ; chainAttempt < chainLimit; chainAttempt++) {
+                PREFETCH_L1(ddsBase + dms->chainTable[chainIndex + chainAttempt]);
+            }
+
+            for (chainAttempt = 0 ; chainAttempt < chainLimit; chainAttempt++, chainIndex++) {
                 size_t currentMl=0;
                 const BYTE* match;
                 matchIndex = dms->chainTable[chainIndex];