add hashtable head prefetching

diff --git a/lib/compress/zstd_lazy.c b/lib/compress/zstd_lazy.c
index 096980db31707d7dec81e585a3d3759de0fbff8e..fd76a55bbeba948d55b5c2708f3eac768ea6019a 100644 (file)
--- a/lib/compress/zstd_lazy.c
+++ b/lib/compress/zstd_lazy.c
@@ -525,6 +525,11 @@ size_t ZSTD_HcFindBestMatch_generic (
     /* HC4 match finder */
     U32 matchIndex = ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, mls);
 
+    if (dictMode == ZSTD_dictMatchState && ms->dictMatchState->enableDedicatedDictSearch)
+        PREFETCH_L1(ms->dictMatchState->hashTable +
+            (ZSTD_hashPtr(ip, ms->dictMatchState->cParams.hashLog - DD_BLOG,
+            ms->dictMatchState->cParams.minMatch) << DD_BLOG));
+
     for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
         size_t currentMl=0;
         if ((dictMode != ZSTD_extDict) || matchIndex >= dictLimit) {