From: Yann Collet <yann.collet.73@gmail.com>
Date: Sun, 4 Feb 2024 01:26:47 +0000 (-0800)
Subject: minor optimization, mostly for clarity
X-Git-Tag: v1.5.6^2~70^2~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8168a451e58261baf9a53b0c1bcfdaff2ba0480d;p=thirdparty%2Fzstd.git

minor optimization, mostly for clarity
---

diff --git a/lib/compress/zstd_opt.c b/lib/compress/zstd_opt.c
index 2c4af2f06..bbf367b24 100644
--- a/lib/compress/zstd_opt.c
+++ b/lib/compress/zstd_opt.c
@@ -1181,7 +1181,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
                 }
                 last_pos = pos-1;
                 opt[pos].price = ZSTD_MAX_PRICE;
-                opt[pos+1].price = ZSTD_MAX_PRICE;
             }
         }
 
@@ -1202,19 +1201,17 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
                     DEBUGLOG(7, "cPos:%zi==rPos:%u : better price (%.2f<=%.2f) using literal (ll==%u) (hist:%u,%u,%u)",
                                 inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), litlen,
                                 opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]);
-                    opt[cur].mlen = opt[cur-1].mlen;
-                    opt[cur].off = opt[cur-1].off;
+                    opt[cur] = opt[cur-1];
                     opt[cur].litlen = litlen;
                     opt[cur].price = price;
-                    ZSTD_memcpy(opt[cur].rep, opt[cur - 1].rep, sizeof(repcodes_t));
                     if ((optLevel == 2) /* additional check only for high modes */
                       && (prevMatch.litlen == 0) /* interrupt a match */
-                      && (LL_INCPRICE(1) < 0) ) /* ll1 is cheaper than ll0 */
-                    {
+                      && (LL_INCPRICE(1) < 0) /* ll1 is cheaper than ll0 */
+                    ) {
                         /* check next position, in case it would be cheaper */
                         int with1literal = prevMatch.price + LIT_PRICE(ip+cur) + LL_INCPRICE(1);
                         int withMoreLiterals = price + LIT_PRICE(ip+cur) + LL_INCPRICE(litlen+1);
-                        DEBUGLOG(7, "But at next rPos %u : match+1lit %.2f vs %ulits %.2f",
+                        DEBUGLOG(7, "then at next rPos %u : match+1lit %.2f vs %ulits %.2f",
                                 cur+1, ZSTD_fCost(with1literal), litlen+1, ZSTD_fCost(withMoreLiterals));
                         if ( (with1literal < withMoreLiterals)
                           && (with1literal < opt[cur+1].price) ) {
@@ -1230,13 +1227,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
                             opt[cur+1].litlen = 1;
                             opt[cur+1].price = with1literal;
                             if (last_pos < cur+1) last_pos = cur+1;
-#if 0
-                            /* but, for following byte, get back to literal run */
-                            opt[cur+2] = opt[cur];
-                            opt[cur+2].litlen += 2;
-                            opt[cur+2].price += LIT_PRICE(ip+cur) + LIT_PRICE(ip+cur+1) + LL_INCPRICE(litlen+1) + LL_INCPRICE(litlen+2);
-                            if (last_pos < cur+2) last_pos = cur+2;
-#endif
                         }
                     }
                 } else {
@@ -1325,7 +1315,6 @@ ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
                         }
             }   }   }
             opt[last_pos+1].price = ZSTD_MAX_PRICE;
-            opt[last_pos+2].price = ZSTD_MAX_PRICE;
         }  /* for (cur = 1; cur <= last_pos; cur++) */
 
         lastStretch = opt[last_pos];