From: W. Felix Handte <w@felixhandte.com>
Date: Thu, 19 Aug 2021 17:58:09 +0000 (-0400)
Subject: Add `ip1 + 128` Prefetch; Tiny Cleanup
X-Git-Tag: v1.5.1~1^2~116^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57a100f6dcb46fff20eacdfc9fc000b0f226b76f;p=thirdparty%2Fzstd.git

Add `ip1 + 128` Prefetch; Tiny Cleanup
---

diff --git a/lib/compress/zstd_fast.c b/lib/compress/zstd_fast.c
index c43c8a6af..ebbef4919 100644
--- a/lib/compress/zstd_fast.c
+++ b/lib/compress/zstd_fast.c
@@ -295,7 +295,9 @@ _start: /* Requires: ip0 */
     idx = hashTable[hash0];
 
     do {
+        /* load repcode match for ip[2]*/
         const U32 rval = MEM_read32(ip2 - rep_offset1);
+
         current0 = ip0 - base;
 
         /* write back hash table entry */
@@ -334,18 +336,18 @@ _start: /* Requires: ip0 */
         /* lookup ip[1] */
         idx = hashTable[hash0];
 
-        /* advance to next positions */
-        {
-            if (ip1 >= nextStep) {
-                PREFETCH_L1(ip1 + 64);
-                step++;
-                nextStep += kStepIncr;
-            }
-
-            ip0 = ip1;
-            ip1 = ip2;
-            ip2 = ip2 + step;
+        /* calculate step */
+        if (ip1 >= nextStep) {
+            PREFETCH_L1(ip1 + 64);
+            PREFETCH_L1(ip1 + 128);
+            step++;
+            nextStep += kStepIncr;
         }
+
+        /* advance to next positions */
+        ip0 = ip1;
+        ip1 = ip2;
+        ip2 += step;
     } while (ip2 < ilimit);
 
 _cleanup: