From: inikep <inikep@gmail.com>
Date: Tue, 5 Apr 2016 08:30:05 +0000 (+0200)
Subject: support for ZSTD_REP_NUM=3
X-Git-Tag: v0.6.0^2~17^2~16^2~8^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ba73d1bb6b7d13a460fa118bfebbfe5453c0f41b;p=thirdparty%2Fzstd.git

support for ZSTD_REP_NUM=3
---

diff --git a/lib/zstd_compress.c b/lib/zstd_compress.c
index e1ca3021e..95cd8ff2d 100644
--- a/lib/zstd_compress.c
+++ b/lib/zstd_compress.c
@@ -1736,16 +1736,19 @@ void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
         /* store sequence */
 _storeSequence:
         {
-#if ZSTD_REP_NUM == 4
             if (offset >= ZSTD_REP_NUM) {
+#if ZSTD_REP_NUM > 3
                 rep[3] = rep[2];
+#endif
                 rep[2] = rep[1];
                 rep[1] = rep[0];
                 rep[0] = offset - ZSTD_REP_MOVE;
             } else {
                 if (offset != 0) {
                     size_t temp = rep[offset];
+#if ZSTD_REP_NUM > 3
                     if (offset > 2) rep[3] = rep[2];
+#endif
                     if (offset > 1) rep[2] = rep[1];
                     if (offset > 0) rep[1] = rep[0];
                     rep[0] = temp;
@@ -1753,11 +1756,7 @@ _storeSequence:
 
                 if (offset<=1 && start==anchor) offset = 1-offset;
             }
-#else
-            if (offset >= ZSTD_REP_NUM) {
-                rep[1] = rep[0]; rep[0] = offset - ZSTD_REP_MOVE;
-            }
-#endif
+
             size_t const litLength = start - anchor;
 
             ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
diff --git a/lib/zstd_decompress.c b/lib/zstd_decompress.c
index 6ad49ee7a..037b6cb2e 100644
--- a/lib/zstd_decompress.c
+++ b/lib/zstd_decompress.c
@@ -656,51 +656,7 @@ static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState, const U32 mls)
                  0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF, /*fake*/ 1, 1, 1, 1, 1 };
 
     /* sequence */
-#if ZSTD_REP_NUM == 1
-#if 1
-    {   size_t const offset = ofCode ? OF_base[ofCode] + BIT_readBits(&(seqState->DStream), ofBits) - ZSTD_REP_MOVE :   /* <=  26 bits */
-                                       llCode ? seq->offset : seqState->prevOffset[0];
-        if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
-        if (ofCode | !llCode) seqState->prevOffset[0] = seq->offset;   /* cmove */
-        seq->offset = offset;
-    }
-#else
-    {   size_t offset;
-        if (ofCode) {
-            offset = OF_base[ofCode] + BIT_readBits(&(seqState->DStream), ofBits) - ZSTD_REP_MOVE;   /* <=  26 bits */
-            if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
-            seqState->prevOffset[0] = seq->offset;   /* cmove */
-        } else {
-            if (llCode) {
-                offset = seq->offset;
-            } else {
-                offset = seqState->prevOffset[0];
-                seqState->prevOffset[0] = seq->offset;
-            }
-        }
-        seq->offset = offset;
-    }
-#endif
-
-
-#else // ZSTD_REP_NUM == 1
-
-
     {   size_t offset;
-#if 0
-        if (!ofCode) {
-            if (!llCode) {
-                offset = seqState->prevOffset[1];
-                seqState->prevOffset[1] = seqState->prevOffset[0];
-                seqState->prevOffset[0] = offset;
-
-            } else {
-                offset = seqState->prevOffset[0];
-            }
-        } else {
-            offset = OF_base[ofCode] + BIT_readBits(&(seqState->DStream), ofBits);   /* <=  26 bits */
-            if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
-#else
         if (!ofCode)
             offset = 0;
         else {
@@ -708,37 +664,34 @@ static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState, const U32 mls)
             if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
         }
         
-        {
+        if (offset < ZSTD_REP_NUM) {
+            if (llCode == 0 && offset <= 1) offset = 1-offset;
+
+            if (offset != 0) {
+                size_t temp = seqState->prevOffset[offset];
+                if (offset != 1) {
+#if ZSTD_REP_NUM > 3
+                    if (offset == 3) seqState->prevOffset[3] = seqState->prevOffset[2];
 #endif
-            if (offset < ZSTD_REP_NUM) {
-                if (llCode == 0 && offset <= 1) offset = 1-offset;
-
-                if (offset != 0) {
-                    size_t temp = seqState->prevOffset[offset];
-                    if (offset != 1) {
-                        if (offset == 3) seqState->prevOffset[3] = seqState->prevOffset[2];
-                        seqState->prevOffset[2] = seqState->prevOffset[1];
-                    }
-                    seqState->prevOffset[1] = seqState->prevOffset[0];
-                    seqState->prevOffset[0] = offset = temp;
-
-                } else {
-                    offset = seqState->prevOffset[0];
+                    seqState->prevOffset[2] = seqState->prevOffset[1];
                 }
+                seqState->prevOffset[1] = seqState->prevOffset[0];
+                seqState->prevOffset[0] = offset = temp;
+
             } else {
-                offset -= ZSTD_REP_MOVE;
-                seqState->prevOffset[3] = seqState->prevOffset[2];
-                seqState->prevOffset[2] = seqState->prevOffset[1];
-                seqState->prevOffset[1] = seqState->prevOffset[0];               
-                seqState->prevOffset[0] = offset;
+                offset = seqState->prevOffset[0];
             }
+        } else {
+            offset -= ZSTD_REP_MOVE;
+#if ZSTD_REP_NUM > 3
+            seqState->prevOffset[3] = seqState->prevOffset[2];
+#endif
+            seqState->prevOffset[2] = seqState->prevOffset[1];
+            seqState->prevOffset[1] = seqState->prevOffset[0];               
+            seqState->prevOffset[0] = offset;
         }
         seq->offset = offset;
     }
-    
-
-
-#endif
 
     seq->matchLength = ML_base[mlCode] + mls + ((mlCode>31) ? BIT_readBits(&(seqState->DStream), mlBits) : 0);   /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits>24)) BIT_reloadDStream(&(seqState->DStream));
diff --git a/lib/zstd_internal.h b/lib/zstd_internal.h
index 951617d5d..e1279a78c 100644
--- a/lib/zstd_internal.h
+++ b/lib/zstd_internal.h
@@ -64,15 +64,10 @@
 
 #define ZSTD_OPT_NUM    (1<<12)
 #define ZSTD_DICT_MAGIC  0xEC30A435
-#if 1
-    #define ZSTD_REP_NUM    4
-    #define ZSTD_REP_INIT   4
-    #define ZSTD_REP_MOVE   (ZSTD_REP_NUM-1)
-#else
-    #define ZSTD_REP_NUM    1
-    #define ZSTD_REP_INIT   2
-    #define ZSTD_REP_MOVE   0 //(ZSTD_REP_NUM-1)
-#endif
+
+#define ZSTD_REP_NUM    3
+#define ZSTD_REP_INIT   ZSTD_REP_NUM
+#define ZSTD_REP_MOVE   (ZSTD_REP_NUM-1)
 
 #define KB *(1 <<10)
 #define MB *(1 <<20)
diff --git a/lib/zstd_opt.h b/lib/zstd_opt.h
index 684eedb11..003823230 100644
--- a/lib/zstd_opt.h
+++ b/lib/zstd_opt.h
@@ -551,13 +551,17 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
            mlen = opt[cur].mlen;
 
            if (opt[cur].off >= ZSTD_REP_NUM) {
+#if ZSTD_REP_NUM > 3
                 opt[cur].rep[3] = opt[cur-mlen].rep[2];
+#endif
                 opt[cur].rep[2] = opt[cur-mlen].rep[1];
                 opt[cur].rep[1] = opt[cur-mlen].rep[0];
                 opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE;               
                 ZSTD_LOG_ENCODE("%d: COPYREP_OFF cur=%d mlen=%d rep=%d rep[1]=%d\n", (int)(inr-base), cur, mlen, opt[cur].rep[0], opt[cur].rep[1]);
            } else {
+#if ZSTD_REP_NUM > 3
                 opt[cur].rep[3] = (opt[cur].off > 2) ? opt[cur-mlen].rep[2] : opt[cur-mlen].rep[3];
+#endif
                 opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
                 opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
                 opt[cur].rep[0] = opt[cur-mlen].rep[opt[cur].off];
@@ -684,7 +688,9 @@ _storeSequence:   /* cur, last_pos, best_mlen, best_off have to be set */
             ZSTD_LOG_ENCODE("%d/%d: ENCODE literals=%d mlen=%d off=%d rep1=%d rep[1]=%d\n", (int)(ip-base), (int)(iend-base), (int)(litLength), (int)mlen, (int)(offset), (int)rep[0], (int)rep[1]);
 
             if (offset >= ZSTD_REP_NUM) {
+#if ZSTD_REP_NUM > 3
                 rep[3] = rep[2];
+#endif
                 rep[2] = rep[1];
                 rep[1] = rep[0];               
                 rep[0] = offset - ZSTD_REP_MOVE;               
@@ -692,7 +698,9 @@ _storeSequence:   /* cur, last_pos, best_mlen, best_off have to be set */
                 if (offset != 0) {
                     size_t temp = rep[offset];
                     if (offset != 1) {
+#if ZSTD_REP_NUM > 3
                         if (offset == 3) rep[3] = rep[2];
+#endif
                         rep[2] = rep[1];
                     }
                     rep[1] = rep[0];