From c1d7e4f67598d8a86ff5a912730f47f65c9cb8db Mon Sep 17 00:00:00 2001 From: "yann.collet.73@gmail.com" Date: Tue, 8 Jan 2013 07:23:07 +0000 Subject: LZ4HC : compression speed improved under Visual Bench mode : option to pause at the end git-svn-id: https://lz4.googlecode.com/svn/trunk@88 650e7d94-2a16-8b24-b05c-7c0b3f6821cd --- bench.c | 7 + bench.h | 1 + lz4demo.c | 5 +- lz4hc.c | 753 +++++++++++++++++++++++++++++++++----------------------------- 4 files changed, 414 insertions(+), 352 deletions(-) diff --git a/bench.c b/bench.c index 015c36e..2758007 100644 --- a/bench.c +++ b/bench.c @@ -133,6 +133,7 @@ struct compressionParameters //************************************** static int chunkSize = DEFAULT_CHUNKSIZE; static int nbIterations = NBLOOPS; +static int BMK_pause = 0; void BMK_SetBlocksize(int bsize) { @@ -146,6 +147,10 @@ void BMK_SetNbIterations(int nbLoops) DISPLAY("- %i iterations-", nbIterations); } +void BMK_SetPause() +{ + BMK_pause = 1; +} //********************************************************* // Private functions @@ -462,6 +467,8 @@ int BMK_benchFile(char** fileNamesTable, int nbFiles, int cLevel) if (nbFiles > 1) printf("%-16.16s :%10llu ->%10llu (%5.2f%%), %6.1f MB/s , %6.1f MB/s\n", " TOTAL", (long long unsigned int)totals, (long long unsigned int)totalz, (double)totalz/(double)totals*100., (double)totals/totalc/1000., (double)totals/totald/1000.); + if (BMK_pause) { printf("press enter...\n"); getchar(); } + return 0; } diff --git a/bench.h b/bench.h index f97eb51..a55c3ce 100644 --- a/bench.h +++ b/bench.h @@ -32,6 +32,7 @@ int BMK_benchFile(char** fileNamesTable, int nbFiles, int cLevel); // Parameters void BMK_SetBlocksize(int bsize); void BMK_SetNbIterations(int nbLoops); +void BMK_SetPause(); diff --git a/lz4demo.c b/lz4demo.c index 8b9a0b9..85edcf0 100644 --- a/lz4demo.c +++ b/lz4demo.c @@ -368,7 +368,10 @@ int main(int argc, char** argv) // Modify Nb Iterations (benchmark only) if ( argument[0] =='i' ) { int iters = argument[1] - '0'; BMK_SetNbIterations(iters); continue; } - // Test + // Pause at the end (benchmark only) + if ( argument[0] =='p' ) { BMK_SetPause(); continue; } + + // Test if ( argument[0] =='t' ) { decode=1; output_filename=nulmark; continue; } } diff --git a/lz4hc.c b/lz4hc.c index d563fde..7fe78da 100644 --- a/lz4hc.c +++ b/lz4hc.c @@ -83,8 +83,9 @@ #endif #ifdef _MSC_VER -#define inline __forceinline // Visual is not C99, but supports some kind of inline -#include // For Visual 2005 +# define inline __inline // Visual is not C99, but supports some kind of inline +# define forceinline __forceinline +# include // For Visual 2005 # if LZ4_ARCH64 // 64-bit # pragma intrinsic(_BitScanForward64) // For Visual 2005 # pragma intrinsic(_BitScanReverse64) // For Visual 2005 @@ -92,6 +93,12 @@ # pragma intrinsic(_BitScanForward) // For Visual 2005 # pragma intrinsic(_BitScanReverse) // For Visual 2005 # endif +#else +# ifdef __GNUC__ +# define forceinline inline __attribute__((always_inline)) +# else +# define forceinline inline +# endif #endif #ifdef _MSC_VER // Visual Studio @@ -211,24 +218,23 @@ typedef struct _U64_S { U64 v; } U64_S; //************************************************************ typedef struct { - const BYTE* base; - HTYPE hashTable[HASHTABLESIZE]; - U16 chainTable[MAXD]; - const BYTE* nextToUpdate; + const BYTE* base; + HTYPE hashTable[HASHTABLESIZE]; + U16 chainTable[MAXD]; + const BYTE* nextToUpdate; } LZ4HC_Data_Structure; //************************************** // Macros //************************************** -#define LZ4_WILDCOPY(s,d,e) do { LZ4_COPYPACKET(s,d) } while (d> ((MINMATCH*8)-HASH_LOG)) -#define HASH_VALUE(p) HASH_FUNCTION(A32(p)) -#define HASH_POINTER(p) (HashTable[HASH_VALUE(p)] + base) -#define DELTANEXT(p) chainTable[(size_t)(p) & MAXD_MASK] -#define GETNEXT(p) ((p) - (size_t)DELTANEXT(p)) -#define ADD_HASH(p) { size_t delta = (p) - HASH_POINTER(p); if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; DELTANEXT(p) = (U16)delta; HashTable[HASH_VALUE(p)] = (p) - base; } +#define LZ4_WILDCOPY(s,d,e) do { LZ4_COPYPACKET(s,d) } while (d> ((MINMATCH*8)-HASH_LOG)) +#define HASH_VALUE(p) HASH_FUNCTION(A32(p)) +#define HASH_POINTER(p) (HashTable[HASH_VALUE(p)] + base) +#define DELTANEXT(p) chainTable[(size_t)(p) & MAXD_MASK] +#define GETNEXT(p) ((p) - (size_t)DELTANEXT(p)) //************************************** @@ -246,11 +252,11 @@ inline static int LZ4_NbCommonBytes (register U64 val) #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_clzll(val) >> 3); #else - int r; - if (!(val>>32)) { r=4; } else { r=0; val>>=32; } - if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; } - r += (!val); - return r; + int r; + if (!(val>>32)) { r=4; } else { r=0; val>>=32; } + if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; } + r += (!val); + return r; #endif #else #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) @@ -260,8 +266,8 @@ inline static int LZ4_NbCommonBytes (register U64 val) #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_ctzll(val) >> 3); #else - static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 }; - return DeBruijnBytePos[((U64)((val & -val) * 0x0218A392CDABBD3F)) >> 58]; + static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 }; + return DeBruijnBytePos[((U64)((val & -val) * 0x0218A392CDABBD3F)) >> 58]; #endif #endif } @@ -272,27 +278,27 @@ inline static int LZ4_NbCommonBytes (register U32 val) { #if defined(LZ4_BIG_ENDIAN) #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) - unsigned long r = 0; + unsigned long r; _BitScanReverse( &r, val ); return (int)(r>>3); #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_clz(val) >> 3); #else - int r; - if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; } - r += (!val); - return r; + int r; + if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; } + r += (!val); + return r; #endif #else #if defined(_MSC_VER) && !defined(LZ4_FORCE_SW_BITCOUNT) - unsigned long r = 0; + unsigned long r; _BitScanForward( &r, val ); return (int)(r>>3); #elif defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304) && !defined(LZ4_FORCE_SW_BITCOUNT) return (__builtin_ctz(val) >> 3); #else - static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 }; - return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27]; + static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 }; + return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27]; #endif #endif } @@ -302,166 +308,211 @@ inline static int LZ4_NbCommonBytes (register U32 val) inline static int LZ4HC_Init (LZ4HC_Data_Structure* hc4, const BYTE* base) { - MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); - MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); - hc4->nextToUpdate = base + LZ4_ARCH64; - hc4->base = base; - return 1; + MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable)); + MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable)); + hc4->nextToUpdate = base + LZ4_ARCH64; + hc4->base = base; + return 1; } inline static void* LZ4HC_Create (const BYTE* base) { - void* hc4 = ALLOCATOR(sizeof(LZ4HC_Data_Structure)); + void* hc4 = ALLOCATOR(sizeof(LZ4HC_Data_Structure)); - LZ4HC_Init (hc4, base); - return hc4; + LZ4HC_Init ((LZ4HC_Data_Structure*)hc4, base); + return hc4; } inline static int LZ4HC_Free (void** LZ4HC_Data) { - FREEMEM(*LZ4HC_Data); - *LZ4HC_Data = NULL; - return (1); + FREEMEM(*LZ4HC_Data); + *LZ4HC_Data = NULL; + return (1); } -inline static void LZ4HC_Insert (LZ4HC_Data_Structure* hc4, const BYTE* ip) +// Update chains up to ip (excluded) +forceinline static void LZ4HC_Insert (LZ4HC_Data_Structure* hc4, const BYTE* ip) { - U16* chainTable = hc4->chainTable; - HTYPE* HashTable = hc4->hashTable; - INITBASE(base,hc4->base); - - while(hc4->nextToUpdate < ip) - { - ADD_HASH(hc4->nextToUpdate); - hc4->nextToUpdate++; - } + U16* chainTable = hc4->chainTable; + HTYPE* HashTable = hc4->hashTable; + INITBASE(base,hc4->base); + + while(hc4->nextToUpdate < ip) + { + const BYTE* p = hc4->nextToUpdate; + size_t delta = (p) - HASH_POINTER(p); + if (delta>MAX_DISTANCE) delta = MAX_DISTANCE; + DELTANEXT(p) = (U16)delta; + HashTable[HASH_VALUE(p)] = (p) - base; + hc4->nextToUpdate++; + } } -inline static int LZ4HC_InsertAndFindBestMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* const matchlimit, const BYTE** matchpos) +forceinline static size_t LZ4HC_CommonLength (const BYTE* p1, const BYTE* p2, const BYTE* const matchlimit) { - U16* const chainTable = hc4->chainTable; - HTYPE* const HashTable = hc4->hashTable; - const BYTE* ref; - INITBASE(base,hc4->base); - int nbAttempts=MAX_NB_ATTEMPTS; - int ml=0; - - // HC4 match finder - LZ4HC_Insert(hc4, ip); - ref = HASH_POINTER(ip); - while ((ref >= (ip-MAX_DISTANCE)) && (nbAttempts)) - { - nbAttempts--; - if (*(ref+ml) == *(ip+ml)) - if (A32(ref) == A32(ip)) - { - const BYTE* reft = ref+MINMATCH; - const BYTE* ipt = ip+MINMATCH; - - while (ipt ml) { ml = (int)(ipt-ip); *matchpos = ref; } - } - ref = GETNEXT(ref); - } - return ml; +forceinline static int LZ4HC_InsertAndFindBestMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* const matchlimit, const BYTE** matchpos) +{ + U16* const chainTable = hc4->chainTable; + HTYPE* const HashTable = hc4->hashTable; + const BYTE* ref; + INITBASE(base,hc4->base); + int nbAttempts=MAX_NB_ATTEMPTS; + size_t ml=0; + + // HC4 match finder + LZ4HC_Insert(hc4, ip); + ref = HASH_POINTER(ip); + +#if 1 + if (ref >= ip-4) // potential repetition + { + if (A32(ref) == A32(ip)) // confirmed + { + const U16 delta = (U16)(ip-ref); + const BYTE* ptr = ip; + const BYTE* end; + ml = LZ4HC_CommonLength(ip+MINMATCH, ref+MINMATCH, matchlimit) + MINMATCH; + end = ip + ml - (MINMATCH-1); + while(ptr < end-delta) + { + DELTANEXT(ptr) = delta; // Pre-Load + ptr++; + } + do + { + DELTANEXT(ptr) = delta; + HashTable[HASH_VALUE(ptr)] = (ptr) - base; // Head of chain + ptr++; + } while(ptr < end); + hc4->nextToUpdate = end; + *matchpos = ref; + } + ref = GETNEXT(ref); + } +#endif + + while ((ref >= (ip-MAX_DISTANCE)) && (nbAttempts)) + { + nbAttempts--; + if (*(ref+ml) == *(ip+ml)) + if (A32(ref) == A32(ip)) + { + size_t mlt = LZ4HC_CommonLength(ip+MINMATCH, ref+MINMATCH, matchlimit) + MINMATCH; + if (mlt > ml) { ml = mlt; *matchpos = ref; } + } + ref = GETNEXT(ref); + } + + return (int)ml; } -inline static int LZ4HC_InsertAndGetWiderMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* startLimit, const BYTE* matchlimit, int longest, const BYTE** matchpos, const BYTE** startpos) +forceinline static int LZ4HC_InsertAndGetWiderMatch (LZ4HC_Data_Structure* hc4, const BYTE* ip, const BYTE* startLimit, const BYTE* matchlimit, int longest, const BYTE** matchpos, const BYTE** startpos) { - U16* const chainTable = hc4->chainTable; - HTYPE* const HashTable = hc4->hashTable; - INITBASE(base,hc4->base); - const BYTE* ref; - int nbAttempts = MAX_NB_ATTEMPTS; - int delta = (int)(ip-startLimit); - - // First Match - LZ4HC_Insert(hc4, ip); - ref = HASH_POINTER(ip); - - while ((ref >= ip-MAX_DISTANCE) && (ref >= hc4->base) && (nbAttempts)) - { - nbAttempts--; - if (*(startLimit + longest) == *(ref - delta + longest)) - if (A32(ref) == A32(ip)) - { - const BYTE* reft = ref+MINMATCH; - const BYTE* ipt = ip+MINMATCH; - const BYTE* startt = ip; - - while (iptchainTable; + HTYPE* const HashTable = hc4->hashTable; + INITBASE(base,hc4->base); + const BYTE* ref; + int nbAttempts = MAX_NB_ATTEMPTS; + int delta = (int)(ip-startLimit); + + // First Match + LZ4HC_Insert(hc4, ip); + ref = HASH_POINTER(ip); + + while ((ref >= ip-MAX_DISTANCE) && (ref >= hc4->base) && (nbAttempts)) + { + nbAttempts--; + if (*(startLimit + longest) == *(ref - delta + longest)) + if (A32(ref) == A32(ip)) + { +#if 1 + const BYTE* reft = ref+MINMATCH; + const BYTE* ipt = ip+MINMATCH; + const BYTE* startt = ip; + + while (iptstartLimit) && (reft > hc4->base) && (startt[-1] == reft[-1])) {startt--; reft--;} + while ((startt>startLimit) && (reft > hc4->base) && (startt[-1] == reft[-1])) {startt--; reft--;} - if ((ipt-startt) > longest) - { - longest = (int)(ipt-startt); - *matchpos = reft; - *startpos = startt; - } - } - ref = GETNEXT(ref); - } + if ((ipt-startt) > longest) + { + longest = (int)(ipt-startt); + *matchpos = reft; + *startpos = startt; + } + } + ref = GETNEXT(ref); + } - return longest; + return longest; } -inline static int LZ4_encodeSequence(const BYTE** ip, BYTE** op, const BYTE** anchor, int ml, const BYTE* ref) +forceinline static int LZ4_encodeSequence(const BYTE** ip, BYTE** op, const BYTE** anchor, int ml, const BYTE* ref) { - int length, len; - BYTE* token; + int length, len; + BYTE* token; - // Encode Literal length - length = (int)(*ip - *anchor); - token = (*op)++; - if (length>=(int)RUN_MASK) { *token=(RUN_MASK< 254 ; len-=255) *(*op)++ = 255; *(*op)++ = (BYTE)len; } - else *token = (length<=(int)RUN_MASK) { *token=(RUN_MASK< 254 ; len-=255) *(*op)++ = 255; *(*op)++ = (BYTE)len; } + else *token = (length<=(int)ML_MASK) { *token+=ML_MASK; len-=ML_MASK; for(; len > 509 ; len-=510) { *(*op)++ = 255; *(*op)++ = 255; } if (len > 254) { len-=255; *(*op)++ = 255; } *(*op)++ = (BYTE)len; } - else *token += len; + // Encode MatchLength + len = (int)(ml-MINMATCH); + if (len>=(int)ML_MASK) { *token+=ML_MASK; len-=ML_MASK; for(; len > 509 ; len-=510) { *(*op)++ = 255; *(*op)++ = 255; } if (len > 254) { len-=255; *(*op)++ = 255; } *(*op)++ = (BYTE)len; } + else *token += len; - // Prepare next loop - *ip += ml; - *anchor = *ip; + // Prepare next loop + *ip += ml; + *anchor = *ip; - return 0; + return 0; } @@ -470,218 +521,218 @@ inline static int LZ4_encodeSequence(const BYTE** ip, BYTE** op, const BYTE** an //**************************** int LZ4_compressHCCtx(LZ4HC_Data_Structure* ctx, - const char* source, - char* dest, - int isize) + const char* source, + char* dest, + int isize) { - const BYTE* ip = (const BYTE*) source; - const BYTE* anchor = ip; - const BYTE* const iend = ip + isize; - const BYTE* const mflimit = iend - MFLIMIT; - const BYTE* const matchlimit = (iend - LASTLITERALS); - - BYTE* op = (BYTE*) dest; - - int ml, ml2, ml3, ml0; - const BYTE* ref=NULL; - const BYTE* start2=NULL; - const BYTE* ref2=NULL; - const BYTE* start3=NULL; - const BYTE* ref3=NULL; - const BYTE* start0; - const BYTE* ref0; - - ip++; - - // Main Loop - while (ip < mflimit) - { - ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref)); - if (!ml) { ip++; continue; } - - // saved, in case we would skip too much - start0 = ip; - ref0 = ref; - ml0 = ml; + const BYTE* ip = (const BYTE*) source; + const BYTE* anchor = ip; + const BYTE* const iend = ip + isize; + const BYTE* const mflimit = iend - MFLIMIT; + const BYTE* const matchlimit = (iend - LASTLITERALS); + + BYTE* op = (BYTE*) dest; + + int ml, ml2, ml3, ml0; + const BYTE* ref=NULL; + const BYTE* start2=NULL; + const BYTE* ref2=NULL; + const BYTE* start3=NULL; + const BYTE* ref3=NULL; + const BYTE* start0; + const BYTE* ref0; + + ip++; + + // Main Loop + while (ip < mflimit) + { + ml = LZ4HC_InsertAndFindBestMatch (ctx, ip, matchlimit, (&ref)); + if (!ml) { ip++; continue; } + + // saved, in case we would skip too much + start0 = ip; + ref0 = ref; + ml0 = ml; _Search2: - if (ip+ml < mflimit) - ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 1, matchlimit, ml, &ref2, &start2); - else ml2=ml; - - if (ml2 == ml) // No better match - { - LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); - continue; - } - - if (start0 < ip) - { - if (start2 < ip + ml0) // empirical - { - ip = start0; - ref = ref0; - ml = ml0; - } - } - - // Here, start0==ip - if ((start2 - ip) < 3) // First Match too small : removed - { - ml = ml2; - ip = start2; - ref =ref2; - goto _Search2; - } + if (ip+ml < mflimit) + ml2 = LZ4HC_InsertAndGetWiderMatch(ctx, ip + ml - 2, ip + 1, matchlimit, ml, &ref2, &start2); + else ml2=ml; + + if (ml2 == ml) // No better match + { + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + continue; + } + + if (start0 < ip) + { + if (start2 < ip + ml0) // empirical + { + ip = start0; + ref = ref0; + ml = ml0; + } + } + + // Here, start0==ip + if ((start2 - ip) < 3) // First Match too small : removed + { + ml = ml2; + ip = start2; + ref =ref2; + goto _Search2; + } _Search3: - // Currently we have : - // ml2 > ml1, and - // ip1+3 <= ip2 (usually < ip1+ml1) - if ((start2 - ip) < OPTIMAL_ML) - { - int correction; - int new_ml = ml; - if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML; - if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH; - correction = new_ml - (int)(start2 - ip); - if (correction > 0) - { - start2 += correction; - ref2 += correction; - ml2 -= correction; - } - } - // Now, we have start2 = ip+new_ml, with new_ml=min(ml, OPTIMAL_ML=18) - - if (start2 + ml2 < mflimit) - ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3); - else ml3=ml2; - - if (ml3 == ml2) // No better match : 2 sequences to encode - { - // ip & ref are known; Now for ml - if (start2 < ip+ml) - { - if ((start2 - ip) < OPTIMAL_ML) - { - int correction; - if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; - if (ip+ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH; - correction = ml - (int)(start2 - ip); - if (correction > 0) - { - start2 += correction; - ref2 += correction; - ml2 -= correction; - } - } - else - { - ml = (int)(start2 - ip); - } - } - // Now, encode 2 sequences - LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); - ip = start2; - LZ4_encodeSequence(&ip, &op, &anchor, ml2, ref2); - continue; - } - - if (start3 < ip+ml+3) // Not enough space for match 2 : remove it - { - if (start3 >= (ip+ml)) // can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 - { - if (start2 < ip+ml) - { - int correction = (int)(ip+ml - start2); - start2 += correction; - ref2 += correction; - ml2 -= correction; - if (ml2 < MINMATCH) - { - start2 = start3; - ref2 = ref3; - ml2 = ml3; - } - } - - LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); - ip = start3; - ref = ref3; - ml = ml3; - - start0 = start2; - ref0 = ref2; - ml0 = ml2; - goto _Search2; - } - - start2 = start3; - ref2 = ref3; - ml2 = ml3; - goto _Search3; - } - - // OK, now we have 3 ascending matches; let's write at least the first one - // ip & ref are known; Now for ml - if (start2 < ip+ml) - { - if ((start2 - ip) < (int)ML_MASK) - { - int correction; - if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; - if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH; - correction = ml - (int)(start2 - ip); - if (correction > 0) - { - start2 += correction; - ref2 += correction; - ml2 -= correction; - } - } - else - { - ml = (int)(start2 - ip); - } - } - LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); - - ip = start2; - ref = ref2; - ml = ml2; - - start2 = start3; - ref2 = ref3; - ml2 = ml3; - - goto _Search3; - - } - - // Encode Last Literals - { - int lastRun = (int)(iend - anchor); - if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK< 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } - else *op++ = (lastRun< ml1, and + // ip1+3 <= ip2 (usually < ip1+ml1) + if ((start2 - ip) < OPTIMAL_ML) + { + int correction; + int new_ml = ml; + if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML; + if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = new_ml - (int)(start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + // Now, we have start2 = ip+new_ml, with new_ml=min(ml, OPTIMAL_ML=18) + + if (start2 + ml2 < mflimit) + ml3 = LZ4HC_InsertAndGetWiderMatch(ctx, start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3); + else ml3=ml2; + + if (ml3 == ml2) // No better match : 2 sequences to encode + { + // ip & ref are known; Now for ml + if (start2 < ip+ml) + { + if ((start2 - ip) < OPTIMAL_ML) + { + int correction; + if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; + if (ip+ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = ml - (int)(start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = (int)(start2 - ip); + } + } + // Now, encode 2 sequences + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + ip = start2; + LZ4_encodeSequence(&ip, &op, &anchor, ml2, ref2); + continue; + } + + if (start3 < ip+ml+3) // Not enough space for match 2 : remove it + { + if (start3 >= (ip+ml)) // can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 + { + if (start2 < ip+ml) + { + int correction = (int)(ip+ml - start2); + start2 += correction; + ref2 += correction; + ml2 -= correction; + if (ml2 < MINMATCH) + { + start2 = start3; + ref2 = ref3; + ml2 = ml3; + } + } + + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + ip = start3; + ref = ref3; + ml = ml3; + + start0 = start2; + ref0 = ref2; + ml0 = ml2; + goto _Search2; + } + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + goto _Search3; + } + + // OK, now we have 3 ascending matches; let's write at least the first one + // ip & ref are known; Now for ml + if (start2 < ip+ml) + { + if ((start2 - ip) < (int)ML_MASK) + { + int correction; + if (ml > OPTIMAL_ML) ml = OPTIMAL_ML; + if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH; + correction = ml - (int)(start2 - ip); + if (correction > 0) + { + start2 += correction; + ref2 += correction; + ml2 -= correction; + } + } + else + { + ml = (int)(start2 - ip); + } + } + LZ4_encodeSequence(&ip, &op, &anchor, ml, ref); + + ip = start2; + ref = ref2; + ml = ml2; + + start2 = start3; + ref2 = ref3; + ml2 = ml3; + + goto _Search3; + + } + + // Encode Last Literals + { + int lastRun = (int)(iend - anchor); + if (lastRun>=(int)RUN_MASK) { *op++=(RUN_MASK< 254 ; lastRun-=255) *op++ = 255; *op++ = (BYTE) lastRun; } + else *op++ = (lastRun<