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Reduce bit tables to 8bit
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This saves some 1.7Kb in rodata section (x86_64, zstd tool),
while assembler code stays the same except
the type of a few load/extend instructions.

Should not have negative performance implications.
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@nolange
nolange committed Dec 14, 2021
1 parent 56f5823 commit 90d637f
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Showing 6 changed files with 15 additions and 15 deletions.
4 changes: 2 additions & 2 deletions lib/common/zstd_internal.h
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Original file line number Diff line number Diff line change
Expand Up @@ -119,7 +119,7 @@ typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingTy
/* Each table cannot take more than #symbols * FSELog bits */
#define ZSTD_MAX_FSE_HEADERS_SIZE (((MaxML + 1) * MLFSELog + (MaxLL + 1) * LLFSELog + (MaxOff + 1) * OffFSELog + 7) / 8)

static UNUSED_ATTR const U32 LL_bits[MaxLL+1] = {
static UNUSED_ATTR const U8 LL_bits[MaxLL+1] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 2, 2, 3, 3,
Expand All @@ -136,7 +136,7 @@ static UNUSED_ATTR const S16 LL_defaultNorm[MaxLL+1] = {
#define LL_DEFAULTNORMLOG 6 /* for static allocation */
static UNUSED_ATTR const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;

static UNUSED_ATTR const U32 ML_bits[MaxML+1] = {
static UNUSED_ATTR const U8 ML_bits[MaxML+1] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
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2 changes: 1 addition & 1 deletion lib/compress/zstd_compress.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3263,7 +3263,7 @@ static size_t ZSTD_estimateBlockSize_literal(const BYTE* literals, size_t litSiz
static size_t ZSTD_estimateBlockSize_symbolType(symbolEncodingType_e type,
const BYTE* codeTable, size_t nbSeq, unsigned maxCode,
const FSE_CTable* fseCTable,
const U32* additionalBits,
const U8* additionalBits,
short const* defaultNorm, U32 defaultNormLog, U32 defaultMax,
void* workspace, size_t wkspSize)
{
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2 changes: 1 addition & 1 deletion lib/compress/zstd_compress_superblock.c
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Original file line number Diff line number Diff line change
Expand Up @@ -325,7 +325,7 @@ static size_t ZSTD_estimateSubBlockSize_literal(const BYTE* literals, size_t lit
static size_t ZSTD_estimateSubBlockSize_symbolType(symbolEncodingType_e type,
const BYTE* codeTable, unsigned maxCode,
size_t nbSeq, const FSE_CTable* fseCTable,
const U32* additionalBits,
const U8* additionalBits,
short const* defaultNorm, U32 defaultNormLog, U32 defaultMax,
void* workspace, size_t wkspSize)
{
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18 changes: 9 additions & 9 deletions lib/decompress/zstd_decompress_block.c
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Original file line number Diff line number Diff line change
Expand Up @@ -419,7 +419,7 @@ static const ZSTD_seqSymbol ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = {
}; /* ML_defaultDTable */


static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U32 nbAddBits)
static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U8 nbAddBits)
{
void* ptr = dt;
ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr;
Expand All @@ -431,7 +431,7 @@ static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U32 nbAddB
cell->nbBits = 0;
cell->nextState = 0;
assert(nbAddBits < 255);
cell->nbAdditionalBits = (BYTE)nbAddBits;
cell->nbAdditionalBits = nbAddBits;
cell->baseValue = baseValue;
}

Expand All @@ -443,7 +443,7 @@ static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U32 nbAddB
FORCE_INLINE_TEMPLATE
void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt,
const short* normalizedCounter, unsigned maxSymbolValue,
const U32* baseValue, const U32* nbAdditionalBits,
const U32* baseValue, const U8* nbAdditionalBits,
unsigned tableLog, void* wksp, size_t wkspSize)
{
ZSTD_seqSymbol* const tableDecode = dt+1;
Expand Down Expand Up @@ -554,7 +554,7 @@ void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt,
tableDecode[u].nbBits = (BYTE) (tableLog - BIT_highbit32(nextState) );
tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
assert(nbAdditionalBits[symbol] < 255);
tableDecode[u].nbAdditionalBits = (BYTE)nbAdditionalBits[symbol];
tableDecode[u].nbAdditionalBits = nbAdditionalBits[symbol];
tableDecode[u].baseValue = baseValue[symbol];
}
}
Expand All @@ -563,7 +563,7 @@ void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt,
/* Avoids the FORCE_INLINE of the _body() function. */
static void ZSTD_buildFSETable_body_default(ZSTD_seqSymbol* dt,
const short* normalizedCounter, unsigned maxSymbolValue,
const U32* baseValue, const U32* nbAdditionalBits,
const U32* baseValue, const U8* nbAdditionalBits,
unsigned tableLog, void* wksp, size_t wkspSize)
{
ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue,
Expand All @@ -573,7 +573,7 @@ static void ZSTD_buildFSETable_body_default(ZSTD_seqSymbol* dt,
#if DYNAMIC_BMI2
BMI2_TARGET_ATTRIBUTE static void ZSTD_buildFSETable_body_bmi2(ZSTD_seqSymbol* dt,
const short* normalizedCounter, unsigned maxSymbolValue,
const U32* baseValue, const U32* nbAdditionalBits,
const U32* baseValue, const U8* nbAdditionalBits,
unsigned tableLog, void* wksp, size_t wkspSize)
{
ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue,
Expand All @@ -583,7 +583,7 @@ BMI2_TARGET_ATTRIBUTE static void ZSTD_buildFSETable_body_bmi2(ZSTD_seqSymbol* d

void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
const short* normalizedCounter, unsigned maxSymbolValue,
const U32* baseValue, const U32* nbAdditionalBits,
const U32* baseValue, const U8* nbAdditionalBits,
unsigned tableLog, void* wksp, size_t wkspSize, int bmi2)
{
#if DYNAMIC_BMI2
Expand All @@ -605,7 +605,7 @@ void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr,
symbolEncodingType_e type, unsigned max, U32 maxLog,
const void* src, size_t srcSize,
const U32* baseValue, const U32* nbAdditionalBits,
const U32* baseValue, const U8* nbAdditionalBits,
const ZSTD_seqSymbol* defaultTable, U32 flagRepeatTable,
int ddictIsCold, int nbSeq, U32* wksp, size_t wkspSize,
int bmi2)
Expand All @@ -617,7 +617,7 @@ static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymb
RETURN_ERROR_IF((*(const BYTE*)src) > max, corruption_detected, "");
{ U32 const symbol = *(const BYTE*)src;
U32 const baseline = baseValue[symbol];
U32 const nbBits = nbAdditionalBits[symbol];
U8 const nbBits = nbAdditionalBits[symbol];
ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits);
}
*DTablePtr = DTableSpace;
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2 changes: 1 addition & 1 deletion lib/decompress/zstd_decompress_block.h
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Original file line number Diff line number Diff line change
Expand Up @@ -60,7 +60,7 @@ size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
*/
void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
const short* normalizedCounter, unsigned maxSymbolValue,
const U32* baseValue, const U32* nbAdditionalBits,
const U32* baseValue, const U8* nbAdditionalBits,
unsigned tableLog, void* wksp, size_t wkspSize,
int bmi2);

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2 changes: 1 addition & 1 deletion lib/decompress/zstd_decompress_internal.h
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Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,7 @@ static UNUSED_ATTR const U32 OF_base[MaxOff+1] = {
0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD };

static UNUSED_ATTR const U32 OF_bits[MaxOff+1] = {
static UNUSED_ATTR const U8 OF_bits[MaxOff+1] = {
0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23,
Expand Down

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