minor compression speed optimization

diff --git a/lib/zstd_compress.c b/lib/zstd_compress.c
index 0d84176b3e0825d91a577c1e137e506bd03f61fe..e6b13ca3e1bf748c719dfda10387787b36365d95 100644 (file)
--- a/lib/zstd_compress.c
+++ b/lib/zstd_compress.c
@@ -80,6 +80,7 @@ static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
     ssPtr->lit = ssPtr->litStart;
     ssPtr->litLength = ssPtr->litLengthStart;
     ssPtr->matchLength = ssPtr->matchLengthStart;
+    ssPtr->longLengthID = 0;
 }
 
 
@@ -620,14 +621,16 @@ void ZSTD_seqToCodes(const seqStore_t* seqStorePtr, size_t const nbSeq)
                                           24, 24, 24, 24, 24, 24, 24, 24,
                                           24, 24, 24, 24, 24, 24, 24, 24 };
         const BYTE LL_deltaCode = 19;
-        U16*  const llTable = seqStorePtr->litLengthStart;
+        const U16* const llTable = seqStorePtr->litLengthStart;
         BYTE* const llCodeTable = seqStorePtr->llCodeStart;
         size_t u;
         for (u=0; u<nbSeq; u++) {
-            U32 ll = llTable[u];
-            if (llTable[u] == 65535) { ll = seqStorePtr->longLength; llTable[u] = (U16)ll; }
+            U32 const  ll = llTable[u];
             llCodeTable[u] = (ll>63) ? (BYTE)ZSTD_highbit(ll) + LL_deltaCode : LL_Code[ll];
-    }   }
+        }
+        if (seqStorePtr->longLengthID==1)
+            llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
+    }
 
     /* Offset codes */
     {   const U32* const offsetTable = seqStorePtr->offsetStart;
@@ -646,14 +649,16 @@ void ZSTD_seqToCodes(const seqStore_t* seqStorePtr, size_t const nbSeq)
                                           42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
                                           42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42 };
         const BYTE ML_deltaCode = 36;
-        U16*  const mlTable = seqStorePtr->matchLengthStart;
+        const U16* const mlTable = seqStorePtr->matchLengthStart;
         BYTE* const mlCodeTable = seqStorePtr->mlCodeStart;
         size_t u;
         for (u=0; u<nbSeq; u++) {
-            U32 ml = mlTable[u];
-            if (mlTable[u] == 65535) { ml = seqStorePtr->longLength; mlTable[u] = (U16)ml; }
+            U32 const ml = mlTable[u];
             mlCodeTable[u] = (ml>127) ? (BYTE)ZSTD_highbit(ml) + ML_deltaCode : ML_Code[ml];
-    }   }
+        }
+        if (seqStorePtr->longLengthID==2)
+            mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
+    }
 }
 
 
@@ -864,15 +869,15 @@ MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const B
     seqStorePtr->lit += litLength;
 
     /* literal Length */
-    if (litLength>=65535) { *(seqStorePtr->litLength++) = 65535; seqStorePtr->longLength = (U32)litLength; }
-    else *seqStorePtr->litLength++ = (U16)litLength;
+    if (litLength>0xFFFF) { seqStorePtr->longLengthID = 1; seqStorePtr->longLengthPos = (U32)(seqStorePtr->litLength - seqStorePtr->litLengthStart); }
+    *seqStorePtr->litLength++ = (U16)litLength;
 
     /* match offset */
     *(seqStorePtr->offset++) = (U32)offsetCode + 1;
 
     /* match Length */
-    if (matchCode>=65535) { *(seqStorePtr->matchLength++) = 65535; seqStorePtr->longLength = (U32)matchCode; }
-    else *seqStorePtr->matchLength++ = (U16)matchCode;
+    if (matchCode>0xFFFF) { seqStorePtr->longLengthID = 2; seqStorePtr->longLengthPos = (U32)(seqStorePtr->matchLength - seqStorePtr->matchLengthStart); }
+    *seqStorePtr->matchLength++ = (U16)matchCode;
 }
 
 

diff --git a/lib/zstd_internal.h b/lib/zstd_internal.h
index 9e6ffcafbd58780f63d460fe9c11f90dd5dd716c..31a99cbde83606ef85b8a0b60f54c477116cf38f 100644 (file)
--- a/lib/zstd_internal.h
+++ b/lib/zstd_internal.h
@@ -222,7 +222,8 @@ typedef struct {
     U16*  matchLengthStart;
     U16*  matchLength;
     BYTE* mlCodeStart;
-    U32   longLength;
+    U32   longLengthID;   /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
+    U32   longLengthPos;
     /* opt */
     ZSTD_optimal_t* priceTable;
     ZSTD_match_t* matchTable;