From 26dec498cf1bae39f4842e93b8bfe4d10b0395e9 Mon Sep 17 00:00:00 2001 From: Yann Collet Date: Fri, 4 Nov 2016 07:13:49 -0700 Subject: small compression speed improvement on 64-bits systems --- NEWS | 4 +++- lib/lz4.c | 17 +++++++++-------- 2 files changed, 12 insertions(+), 9 deletions(-) diff --git a/NEWS b/NEWS index b676d86..f98f2c7 100644 --- a/NEWS +++ b/NEWS @@ -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) diff --git a/lib/lz4.c b/lib/lz4.c index 6a6aaf2..0777d5e 100644 --- a/lib/lz4.c +++ b/lib/lz4.c @@ -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<> (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) { -- cgit v0.12