AuroraMiddleware/lz4
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small compression speed improvement on 64-bits systems

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This commit is contained in:
Yann Collet 2016-11-04 07:13:49 -07:00
parent 6d6a3e0fb5
commit 26dec498cf
2 changed files with 12 additions and 9 deletions
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4
NEWS
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@ -1,10 +1,12 @@
v1.7.2
Changed : moved to versioning; package, cli and library have same version number
Improved: Small decompression speed boost (+4%)
Improved: Small decompression speed boost
Improved: Small compression speed improvement on 64-bits systems
Improved: Performance on ARMv6 and ARMv7
Added : Debianization, by Evgeniy Polyakov
Makefile: Generates object files (*.o) for faster (re)compilation on low power systems
Fix : cli : crash on some invalid inputs
Fix : cli : -t correctly validates lz4-compressed files, by Nick Terrell
r131
New : Dos/DJGPP target, thanks to Louis Santillan (#114)

17
lib/lz4.c
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@ -415,27 +415,28 @@ int LZ4_sizeofState() { return LZ4_STREAMSIZE; }
static U32 LZ4_hashSequence(U32 sequence, tableType_t const tableType)
{
if (tableType == byU16)
return (((sequence) * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
return ((sequence * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1)));
else
return (((sequence) * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
return ((sequence * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG));
}
static const U64 prime5bytes = 889523592379ULL;
static U32 LZ4_hashSequence64(size_t sequence, tableType_t const tableType)
static U32 LZ4_hashSequence64(U64 sequence, tableType_t const tableType)
{
const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG;
const U32 hashMask = (1<<hashLog) - 1;
return ((sequence * prime5bytes) >> (40 - hashLog)) & hashMask;
return ((sequence << 24) * prime5bytes) >> (64 - hashLog);
}
static U32 LZ4_hashSequenceT(size_t sequence, tableType_t const tableType)
{
if (LZ4_64bits())
return LZ4_hashSequence64(sequence, tableType);
if (LZ4_64bits()) return LZ4_hashSequence64(sequence, tableType);
return LZ4_hashSequence((U32)sequence, tableType);
}
static U32 LZ4_hashPosition(const void* p, tableType_t tableType) { return LZ4_hashSequenceT(LZ4_read_ARCH(p), tableType); }
static U32 LZ4_hashPosition(const void* p, tableType_t tableType)
{
return LZ4_hashSequenceT(LZ4_read_ARCH(p), tableType);
}
static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t const tableType, const BYTE* srcBase)
{