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added support for MINMATCH=3 on big endian architecture

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changed ZSTD_HASHLOG3_MIN to 2 (4 bytes for MINMACH > 3)
This commit is contained in:
inikep 2016-03-07 10:07:08 +01:00
parent 89c9e1a847
commit e2446b0e36
4 changed files with 22 additions and 21 deletions
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25
lib/mem.h
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@ -187,17 +187,6 @@ MEM_STATIC void MEM_write64(void* memPtr, U64 value)
#endif /* MEM_FORCE_MEMORY_ACCESS */
MEM_STATIC U32 MEM_readMINMATCH(const void* memPtr, U32 length)
{
switch (length)
{
default :
case 4 : return MEM_read32(memPtr);
case 3 : return MEM_read32(memPtr)<<8;
}
}
MEM_STATIC U16 MEM_readLE16(const void* memPtr)
{
if (MEM_isLittleEndian())
@ -286,6 +275,20 @@ MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val)
MEM_writeLE64(memPtr, (U64)val);
}
/* function safe only for comparisons */
MEM_STATIC U32 MEM_readMINMATCH(const void* memPtr, U32 length)
{
switch (length)
{
default :
case 4 : return MEM_read32(memPtr);
case 3 : if (MEM_isLittleEndian())
return MEM_read32(memPtr)<<8;
else
return MEM_read32(memPtr)>>8;
}
}
#if defined (__cplusplus)
}
#endif

2
lib/zstd_compress.c
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@ -876,7 +876,7 @@ static size_t ZSTD_count_2segments(const BYTE* ip, const BYTE* match, const BYTE
***************************************/
static const U32 prime3bytes = 506832829U;
static U32 ZSTD_hash3(U32 u, U32 h) { return ((u << (32-24)) * prime3bytes) >> (32-h) ; }
static size_t ZSTD_hash3Ptr(const void* ptr, U32 h) { return ZSTD_hash3(MEM_read32(ptr), h); }
static size_t ZSTD_hash3Ptr(const void* ptr, U32 h) { return ZSTD_hash3(MEM_readLE32(ptr), h); }
static const U32 prime4bytes = 2654435761U;
static U32 ZSTD_hash4(U32 u, U32 h) { return (u * prime4bytes) >> (32-h) ; }

14
lib/zstd_opt.h
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@ -335,10 +335,9 @@ static U32 ZSTD_BtGetAllMatches (
static U32 ZSTD_BtGetAllMatches_selectMLS (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iLowLimit, const BYTE* const iHighLimit,
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches)
{
(void)iLowLimit; /* unused */
switch(matchLengthSearch)
{
default :
@ -363,10 +362,9 @@ static U32 ZSTD_BtGetAllMatches_extDict (
static U32 ZSTD_BtGetAllMatches_selectMLS_extDict (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iLowLimit, const BYTE* const iHighLimit,
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches)
{
(void)iLowLimit;
switch(matchLengthSearch)
{
default :
@ -447,7 +445,7 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
} while (mlen >= minMatch);
}
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, ip, iend, maxSearches, mls, matches); /* first search (depth 0) */
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches); /* first search (depth 0) */
ZSTD_LOG_PARSER("%d: match_num=%d last_pos=%d\n", (int)(ip-base), match_num, last_pos);
if (!last_pos && !match_num) { ip++; continue; }
@ -567,7 +565,7 @@ void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
} while (mlen >= minMatch);
}
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, ip, iend, maxSearches, mls, matches);
match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches);
ZSTD_LOG_PARSER("%d: ZSTD_GetAllMatches match_num=%d\n", (int)(inr-base), match_num);
if (match_num > 0 && matches[match_num-1].len > sufficient_len) {
@ -779,7 +777,7 @@ void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
best_mlen = (last_pos) ? last_pos : minMatch;
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, ip, iend, maxSearches, mls, matches); /* first search (depth 0) */
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches); /* first search (depth 0) */
ZSTD_LOG_PARSER("%d: match_num=%d last_pos=%d\n", (int)(ip-base), match_num, last_pos);
if (!last_pos && !match_num) { ip++; continue; }
@ -909,7 +907,7 @@ void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
best_mlen = (best_mlen > minMatch) ? best_mlen : minMatch;
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, ip, iend, maxSearches, mls, matches);
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches);
ZSTD_LOG_PARSER("%d: ZSTD_GetAllMatches match_num=%d\n", (int)(inr-base), match_num);
if (match_num > 0 && matches[match_num-1].len > sufficient_len) {

2
lib/zstd_static.h
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@ -65,7 +65,7 @@ extern "C" {
#define ZSTD_HASHLOG_MAX 28
#define ZSTD_HASHLOG_MIN 12
#define ZSTD_HASHLOG3_MAX 24
#define ZSTD_HASHLOG3_MIN 12
#define ZSTD_HASHLOG3_MIN 2
#define ZSTD_SEARCHLOG_MAX (ZSTD_CONTENTLOG_MAX-1)
#define ZSTD_SEARCHLOG_MIN 1
#define ZSTD_SEARCHLENGTH_MAX 7