From: Nick Terrell <terrelln@fb.com>
Date: Wed, 17 Mar 2021 23:50:37 +0000 (-0700)
Subject: [huf][fse] Clean up workspaces
X-Git-Tag: v1.4.10~18^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=756bd59322600d260138a9c1cd95cb4674bc6e05;p=thirdparty%2Fzstd.git

[huf][fse] Clean up workspaces

* Move `counting` to a struct in `FSE_decompress_wksp_body()`
* Fix error code in `FSE_decompress_wksp_body()`
* Rename a variable in `HUF_ReadDTableX2_Workspace`
---

diff --git a/lib/common/fse_decompress.c b/lib/common/fse_decompress.c
index cc45babd9..af865fb4d 100644
--- a/lib/common/fse_decompress.c
+++ b/lib/common/fse_decompress.c
@@ -310,6 +310,11 @@ size_t FSE_decompress_wksp(void* dst, size_t dstCapacity, const void* cSrc, size
     return FSE_decompress_wksp_bmi2(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize, /* bmi2 */ 0);
 }
 
+typedef struct {
+    short count[FSE_MAX_SYMBOL_VALUE + 1];
+} FSE_NormalizedCount;
+
+
 FORCE_INLINE_TEMPLATE size_t FSE_decompress_wksp_body(
         void* dst, size_t dstCapacity,
         const void* cSrc, size_t cSrcSize,
@@ -320,16 +325,15 @@ FORCE_INLINE_TEMPLATE size_t FSE_decompress_wksp_body(
     const BYTE* ip = istart;
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
-    short* counting = (short*) workSpace;
-    size_t const countingSize = sizeof(short) * (FSE_MAX_SYMBOL_VALUE + 1);
-    FSE_DTable* const dtable = (FSE_DTable*)(void*)((BYTE*)workSpace + countingSize);
+    FSE_NormalizedCount* const ncount = (FSE_NormalizedCount*)workSpace;
+    FSE_DTable* const dtable = (FSE_DTable*)(void*)((BYTE*)workSpace + sizeof(*ncount));
 
     DEBUG_STATIC_ASSERT((FSE_MAX_SYMBOL_VALUE + 1) % 2 == 0);
-    if (wkspSize < countingSize) return ERROR(GENERIC);
+    if (wkspSize < sizeof(*ncount)) return ERROR(GENERIC);
 
     /* normal FSE decoding mode */
     {
-        size_t const NCountLength = FSE_readNCount_bmi2(counting, &maxSymbolValue, &tableLog, istart, cSrcSize, bmi2);
+        size_t const NCountLength = FSE_readNCount_bmi2(ncount->count, &maxSymbolValue, &tableLog, istart, cSrcSize, bmi2);
         if (FSE_isError(NCountLength)) return NCountLength;
         if (tableLog > maxLog) return ERROR(tableLog_tooLarge);
         assert(NCountLength <= cSrcSize);
@@ -340,9 +344,9 @@ FORCE_INLINE_TEMPLATE size_t FSE_decompress_wksp_body(
     if (FSE_DECOMPRESS_WKSP_SIZE(tableLog, maxSymbolValue) > wkspSize) return ERROR(tableLog_tooLarge);
     workSpace = dtable + FSE_DTABLE_SIZE_U32(tableLog);
     wkspSize -= FSE_DTABLE_SIZE(tableLog);
-    wkspSize -= countingSize;
+    wkspSize -= sizeof(*ncount);
 
-    CHECK_F( FSE_buildDTable_internal(dtable, counting, maxSymbolValue, tableLog, workSpace, wkspSize) );
+    CHECK_F( FSE_buildDTable_internal(dtable, ncount->count, maxSymbolValue, tableLog, workSpace, wkspSize) );
 
     {
         const void* ptr = dtable;
diff --git a/lib/decompress/huf_decompress.c b/lib/decompress/huf_decompress.c
index 4481484f7..07954a931 100644
--- a/lib/decompress/huf_decompress.c
+++ b/lib/decompress/huf_decompress.c
@@ -620,7 +620,7 @@ typedef struct {
     U32 rankStart0[HUF_TABLELOG_MAX + 2];
     sortedSymbol_t sortedSymbol[HUF_SYMBOLVALUE_MAX + 1];
     BYTE weightList[HUF_SYMBOLVALUE_MAX + 1];
-    U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
+    U32 calleeWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
 } HUF_ReadDTableX2_Workspace;
 
 size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
@@ -635,9 +635,9 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
     HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
     U32 *rankStart;
 
-    HUF_ReadDTableX2_Workspace* wksp = (HUF_ReadDTableX2_Workspace*)workSpace;
+    HUF_ReadDTableX2_Workspace* const wksp = (HUF_ReadDTableX2_Workspace*)workSpace;
 
-    if (sizeof(*wksp) > wkspSize) return ERROR(tableLog_tooLarge);
+    if (sizeof(*wksp) > wkspSize) return ERROR(GENERIC);
 
     rankStart = wksp->rankStart0 + 1;
     ZSTD_memset(wksp->rankStats, 0, sizeof(wksp->rankStats));
@@ -647,7 +647,7 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
     if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
     /* ZSTD_memset(weightList, 0, sizeof(weightList)); */  /* is not necessary, even though some analyzer complain ... */
 
-    iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->wksp, sizeof(wksp->wksp), /* bmi2 */ 0);
+    iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), /* bmi2 */ 0);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
@@ -701,7 +701,7 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
                    wksp->sortedSymbol, sizeOfSort,
                    wksp->rankStart0, wksp->rankVal, maxW,
                    tableLog+1,
-                   wksp->wksp, sizeof(wksp->wksp) / sizeof(U32));
+                   wksp->calleeWksp, sizeof(wksp->calleeWksp) / sizeof(U32));
 
     dtd.tableLog = (BYTE)maxTableLog;
     dtd.tableType = 1;