From: Yann Collet <cyan@fb.com>
Date: Sat, 5 Dec 2020 00:33:39 +0000 (-0800)
Subject: minor speed improvement to HUF_readCTable()
X-Git-Tag: v1.4.7~14^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=68c14bdff296c87bfc7a5447a29c10407121bdd2;p=thirdparty%2Fzstd.git

minor speed improvement to HUF_readCTable()

faster by ~+1-2%
---

diff --git a/lib/common/entropy_common.c b/lib/common/entropy_common.c
index b1213a964..f9fcb1acf 100644
--- a/lib/common/entropy_common.c
+++ b/lib/common/entropy_common.c
@@ -261,11 +261,12 @@ size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
     return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* bmi2 */ 0);
 }
 
-FORCE_INLINE_TEMPLATE size_t HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
-                     U32* nbSymbolsPtr, U32* tableLogPtr,
-                     const void* src, size_t srcSize,
-                     void* workSpace, size_t wkspSize,
-                     int bmi2)
+FORCE_INLINE_TEMPLATE size_t
+HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
+                   U32* nbSymbolsPtr, U32* tableLogPtr,
+                   const void* src, size_t srcSize,
+                   void* workSpace, size_t wkspSize,
+                   int bmi2)
 {
     U32 weightTotal;
     const BYTE* ip = (const BYTE*) src;
@@ -289,7 +290,8 @@ FORCE_INLINE_TEMPLATE size_t HUF_readStats_body(BYTE* huffWeight, size_t hwSize,
     }   }   }
     else  {   /* header compressed with FSE (normal case) */
         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
-        oSize = FSE_decompress_wksp_bmi2(huffWeight, hwSize-1, ip+1, iSize, 6, workSpace, wkspSize, bmi2);   /* max (hwSize-1) values decoded, as last one is implied */
+        /* max (hwSize-1) values decoded, as last one is implied */
+        oSize = FSE_decompress_wksp_bmi2(huffWeight, hwSize-1, ip+1, iSize, 6, workSpace, wkspSize, bmi2);
         if (FSE_isError(oSize)) return oSize;
     }
 
diff --git a/lib/compress/huf_compress.c b/lib/compress/huf_compress.c
index 67f0c928a..359a949a1 100644
--- a/lib/compress/huf_compress.c
+++ b/lib/compress/huf_compress.c
@@ -155,6 +155,7 @@ size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void
 
     /* get symbol weights */
     CHECK_V_F(readSize, HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX+1, rankVal, &nbSymbols, &tableLog, src, srcSize));
+    *hasZeroWeights = (rankVal[0] > 0);
 
     /* check result */
     if (tableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
@@ -169,10 +170,8 @@ size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void
     }   }
 
     /* fill nbBits */
-    *hasZeroWeights = 0;
     {   U32 n; for (n=0; n<nbSymbols; n++) {
             const U32 w = huffWeight[n];
-            *hasZeroWeights |= (w == 0);
             CTable[n].nbBits = (BYTE)(tableLog + 1 - w) & -(w != 0);
     }   }