/* LzmaDec.c -- LZMA Decoder

2018-07-04 : Igor Pavlov : Public domain */

#include "Precomp.h"

#include <string.h>

#include <stdlib.h>

#include <stdint.h>

/* #include "CpuArch.h" */

#include "LzmaDec.h"

#define kNumTopBits 24

#define kTopValue ((UInt32)1 << kNumTopBits)

#define kNumBitModelTotalBits 11

#define kBitModelTotal (1 << kNumBitModelTotalBits)

#define kNumMoveBits 5

#define RC_INIT_SIZE 5

#define NORMALIZE if (range < kTopValue) { range <<= 8; code = (code << 8) | (*buf++); }

#define IF_BIT_0(p) ttt = *(p); NORMALIZE; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)

#define UPDATE_0(p) range = bound; *(p) = (CLzmaProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));

#define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CLzmaProb)(ttt - (ttt >> kNumMoveBits));

#define GET_BIT2(p, i, A0, A1) IF_BIT_0(p) \

  { UPDATE_0(p); i = (i + i); A0; } else \

  { UPDATE_1(p); i = (i + i) + 1; A1; }

#define TREE_GET_BIT(probs, i) { GET_BIT2(probs + i, i, ;, ;); }

#define REV_BIT(p, i, A0, A1) IF_BIT_0(p + i) \

  { UPDATE_0(p + i); A0; } else \

  { UPDATE_1(p + i); A1; }

#define REV_BIT_VAR(  p, i, m) REV_BIT(p, i, i += m; m += m, m += m; i += m; )

#define REV_BIT_CONST(p, i, m) REV_BIT(p, i, i += m;       , i += m * 2; )

#define REV_BIT_LAST( p, i, m) REV_BIT(p, i, i -= m        , ; )

#define TREE_DECODE(probs, limit, i) \

  { i = 1; do { TREE_GET_BIT(probs, i); } while (i < limit); i -= limit; }

/* #define _LZMA_SIZE_OPT */

#ifdef _LZMA_SIZE_OPT

#define TREE_6_DECODE(probs, i) TREE_DECODE(probs, (1 << 6), i)

#else

#define TREE_6_DECODE(probs, i) \

  { i = 1; \

  TREE_GET_BIT(probs, i); \

  TREE_GET_BIT(probs, i); \

  TREE_GET_BIT(probs, i); \

  TREE_GET_BIT(probs, i); \

  TREE_GET_BIT(probs, i); \

  TREE_GET_BIT(probs, i); \

  i -= 0x40; }

#endif

#define NORMAL_LITER_DEC TREE_GET_BIT(prob, symbol)

#define MATCHED_LITER_DEC \

  matchByte += matchByte; \

  bit = offs; \

  offs &= matchByte; \

  probLit = prob + (offs + bit + symbol); \

  GET_BIT2(probLit, symbol, offs ^= bit; , ;)

#define NORMALIZE_CHECK if (range < kTopValue) { if (buf >= bufLimit) return DUMMY_ERROR; range <<= 8; code = (code << 8) | (*buf++); }

#define IF_BIT_0_CHECK(p) ttt = *(p); NORMALIZE_CHECK; bound = (range >> kNumBitModelTotalBits) * (UInt32)ttt; if (code < bound)

#define UPDATE_0_CHECK range = bound;

#define UPDATE_1_CHECK range -= bound; code -= bound;

#define GET_BIT2_CHECK(p, i, A0, A1) IF_BIT_0_CHECK(p) \

  { UPDATE_0_CHECK; i = (i + i); A0; } else \

  { UPDATE_1_CHECK; i = (i + i) + 1; A1; }

#define GET_BIT_CHECK(p, i) GET_BIT2_CHECK(p, i, ; , ;)

#define TREE_DECODE_CHECK(probs, limit, i) \

  { i = 1; do { GET_BIT_CHECK(probs + i, i) } while (i < limit); i -= limit; }

#define REV_BIT_CHECK(p, i, m) IF_BIT_0_CHECK(p + i) \

  { UPDATE_0_CHECK; i += m; m += m; } else \

  { UPDATE_1_CHECK; m += m; i += m; }

#define kNumPosBitsMax 4

#define kNumPosStatesMax (1 << kNumPosBitsMax)

#define kLenNumLowBits 3

#define kLenNumLowSymbols (1 << kLenNumLowBits)

#define kLenNumHighBits 8

#define kLenNumHighSymbols (1 << kLenNumHighBits)

#define LenLow 0

#define LenHigh (LenLow + 2 * (kNumPosStatesMax << kLenNumLowBits))

#define kNumLenProbs (LenHigh + kLenNumHighSymbols)

#define LenChoice LenLow

#define LenChoice2 (LenLow + (1 << kLenNumLowBits))

#define kNumStates 12

#define kNumStates2 16

#define kNumLitStates 7

#define kStartPosModelIndex 4

#define kEndPosModelIndex 14

#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))

#define kNumPosSlotBits 6

#define kNumLenToPosStates 4

#define kNumAlignBits 4

#define kAlignTableSize (1 << kNumAlignBits)

#define kMatchMinLen 2

#define kMatchSpecLenStart (kMatchMinLen + kLenNumLowSymbols * 2 + kLenNumHighSymbols)

/* External ASM code needs same CLzmaProb array layout. So don't change it. */

/* (probs_1664) is faster and better for code size at some platforms */

/*

#ifdef MY_CPU_X86_OR_AMD64

*/

#define kStartOffset 1664

#define GET_PROBS p->probs_1664

/*

#define GET_PROBS p->probs + kStartOffset

#else

#define kStartOffset 0

#define GET_PROBS p->probs

#endif

*/

#define SpecPos (-kStartOffset)

#define IsRep0Long (SpecPos + kNumFullDistances)

#define RepLenCoder (IsRep0Long + (kNumStates2 << kNumPosBitsMax))

#define LenCoder (RepLenCoder + kNumLenProbs)

#define IsMatch (LenCoder + kNumLenProbs)

#define Align (IsMatch + (kNumStates2 << kNumPosBitsMax))

#define IsRep (Align + kAlignTableSize)

#define IsRepG0 (IsRep + kNumStates)

#define IsRepG1 (IsRepG0 + kNumStates)

#define IsRepG2 (IsRepG1 + kNumStates)

#define PosSlot (IsRepG2 + kNumStates)

#define Literal (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))

#define NUM_BASE_PROBS (Literal + kStartOffset)

#if Align != 0 && kStartOffset != 0

  #error Stop_Compiling_Bad_LZMA_kAlign

#endif

#if NUM_BASE_PROBS != 1984

  #error Stop_Compiling_Bad_LZMA_PROBS

#endif

#define LZMA_LIT_SIZE 0x300

#define LzmaProps_GetNumProbs(p) (NUM_BASE_PROBS + ((UInt32)LZMA_LIT_SIZE << ((p)->lc + (p)->lp)))

#define CALC_POS_STATE(processedPos, pbMask) (((processedPos) & (pbMask)) << 4)

#define COMBINED_PS_STATE (posState + state)

#define GET_LEN_STATE (posState)

#define LZMA_DIC_MIN (1 << 12)

/*

p->remainLen : shows status of LZMA decoder:

    < kMatchSpecLenStart : normal remain

    = kMatchSpecLenStart : finished

    = kMatchSpecLenStart + 1 : need init range coder

    = kMatchSpecLenStart + 2 : need init range coder and state

*/

/* ---------- LZMA_DECODE_REAL ---------- */

/*

LzmaDec_DecodeReal_3() can be implemented in external ASM file.

3 - is the code compatibility version of that function for check at link time.

*/

#define LZMA_DECODE_REAL LzmaDec_DecodeReal_3

/*

LZMA_DECODE_REAL()

In:

  RangeCoder is normalized

  if (p->dicPos == limit)

  {

    LzmaDec_TryDummy() was called before to exclude LITERAL and MATCH-REP cases.

    So first symbol can be only MATCH-NON-REP. And if that MATCH-NON-REP symbol

    is not END_OF_PAYALOAD_MARKER, then function returns error code.

  }

Processing:

  first LZMA symbol will be decoded in any case

  All checks for limits are at the end of main loop,

  It will decode new LZMA-symbols while (p->buf < bufLimit && dicPos < limit),

  RangeCoder is still without last normalization when (p->buf < bufLimit) is being checked.

Out:

  RangeCoder is normalized

  Result:

    SZ_OK - OK

    SZ_ERROR_DATA - Error

  p->remainLen:

    < kMatchSpecLenStart : normal remain

    = kMatchSpecLenStart : finished

*/

#ifdef _LZMA_DEC_OPT

int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit);

#else

static

int MY_FAST_CALL LZMA_DECODE_REAL(CLzmaDec *p, SizeT limit, const Byte *bufLimit)

{

  CLzmaProb *probs = GET_PROBS;

  unsigned state = (unsigned)p->state;

  UInt32 rep0 = p->reps[0], rep1 = p->reps[1], rep2 = p->reps[2], rep3 = p->reps[3];

  unsigned pbMask = ((unsigned)1 << (p->prop.pb)) - 1;

  unsigned lc = p->prop.lc;

  unsigned lpMask = ((unsigned)0x100 << p->prop.lp) - ((unsigned)0x100 >> lc);

  Byte *dic = p->dic;

  SizeT dicBufSize = p->dicBufSize;

  SizeT dicPos = p->dicPos;

  UInt32 processedPos = p->processedPos;

  UInt32 checkDicSize = p->checkDicSize;

  unsigned len = 0;

  const Byte *buf = p->buf;

  UInt32 range = p->range;

  UInt32 code = p->code;

  do

  {

    CLzmaProb *prob;

    UInt32 bound;

    unsigned ttt;

    unsigned posState = CALC_POS_STATE(processedPos, pbMask);

    prob = probs + IsMatch + COMBINED_PS_STATE;

    IF_BIT_0(prob)

    {

      unsigned symbol;

      UPDATE_0(prob);

      prob = probs + Literal;

      if (processedPos != 0 || checkDicSize != 0)

        prob += (UInt32)3 * ((((processedPos << 8) + dic[(dicPos == 0 ? dicBufSize : dicPos) - 1]) & lpMask) << lc);

      processedPos++;

      if (state < kNumLitStates)

      {

        state -= (state < 4) ? state : 3;

        symbol = 1;

        #ifdef _LZMA_SIZE_OPT

        do { NORMAL_LITER_DEC } while (symbol < 0x100);

        #else

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        NORMAL_LITER_DEC

        #endif

      }

      else

      {

        unsigned matchByte = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];

        unsigned offs = 0x100;

        state -= (state < 10) ? 3 : 6;

        symbol = 1;

        #ifdef _LZMA_SIZE_OPT

        do

        {

          unsigned bit;

          CLzmaProb *probLit;

          MATCHED_LITER_DEC

        }

        while (symbol < 0x100);

        #else

        {

          unsigned bit;

          CLzmaProb *probLit;

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

          MATCHED_LITER_DEC

        }

        #endif

      }

      dic[dicPos++] = (Byte)symbol;

      continue;

    }

    {

      UPDATE_1(prob);

      prob = probs + IsRep + state;

      IF_BIT_0(prob)

      {

        UPDATE_0(prob);

        state += kNumStates;

        prob = probs + LenCoder;

      }

      else

      {

        UPDATE_1(prob);

        /*

        // that case was checked before with kBadRepCode

        if (checkDicSize == 0 && processedPos == 0)

          return SZ_ERROR_DATA;

        */

        prob = probs + IsRepG0 + state;

        IF_BIT_0(prob)

        {

          UPDATE_0(prob);

          prob = probs + IsRep0Long + COMBINED_PS_STATE;

          IF_BIT_0(prob)

          {

            UPDATE_0(prob);

            dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];

            dicPos++;

            processedPos++;

            state = state < kNumLitStates ? 9 : 11;

            continue;

          }

          UPDATE_1(prob);

        }

        else

        {

          UInt32 distance;

          UPDATE_1(prob);

          prob = probs + IsRepG1 + state;

          IF_BIT_0(prob)

          {

            UPDATE_0(prob);

            distance = rep1;

          }

          else

          {

            UPDATE_1(prob);

            prob = probs + IsRepG2 + state;

            IF_BIT_0(prob)

            {

              UPDATE_0(prob);

              distance = rep2;

            }

            else

            {

              UPDATE_1(prob);

              distance = rep3;

              rep3 = rep2;

            }

            rep2 = rep1;

          }

          rep1 = rep0;

          rep0 = distance;

        }

        state = state < kNumLitStates ? 8 : 11;

        prob = probs + RepLenCoder;

      }

      #ifdef _LZMA_SIZE_OPT

      {

        unsigned lim, offset;

        CLzmaProb *probLen = prob + LenChoice;

        IF_BIT_0(probLen)

        {

          UPDATE_0(probLen);

          probLen = prob + LenLow + GET_LEN_STATE;

          offset = 0;

          lim = (1 << kLenNumLowBits);

        }

        else

        {

          UPDATE_1(probLen);

          probLen = prob + LenChoice2;

          IF_BIT_0(probLen)

          {

            UPDATE_0(probLen);

            probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);

            offset = kLenNumLowSymbols;

            lim = (1 << kLenNumLowBits);

          }

          else

          {

            UPDATE_1(probLen);

            probLen = prob + LenHigh;

            offset = kLenNumLowSymbols * 2;

            lim = (1 << kLenNumHighBits);

          }

        }

        TREE_DECODE(probLen, lim, len);

        len += offset;

      }

      #else

      {

        CLzmaProb *probLen = prob + LenChoice;

        IF_BIT_0(probLen)

        {

          UPDATE_0(probLen);

          probLen = prob + LenLow + GET_LEN_STATE;

          len = 1;

          TREE_GET_BIT(probLen, len);

          TREE_GET_BIT(probLen, len);

          TREE_GET_BIT(probLen, len);

          len -= 8;

        }

        else

        {

          UPDATE_1(probLen);

          probLen = prob + LenChoice2;

          IF_BIT_0(probLen)

          {

            UPDATE_0(probLen);

            probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);

            len = 1;

            TREE_GET_BIT(probLen, len);

            TREE_GET_BIT(probLen, len);

            TREE_GET_BIT(probLen, len);

          }

          else

          {

            UPDATE_1(probLen);

            probLen = prob + LenHigh;

            TREE_DECODE(probLen, (1 << kLenNumHighBits), len);

            len += kLenNumLowSymbols * 2;

          }

        }

      }

      #endif

      if (state >= kNumStates)

      {

        UInt32 distance;

        prob = probs + PosSlot +

            ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << kNumPosSlotBits);

        TREE_6_DECODE(prob, distance);

        if (distance >= kStartPosModelIndex)

        {

          unsigned posSlot = (unsigned)distance;

          unsigned numDirectBits = (unsigned)(((distance >> 1) - 1));

          distance = (2 | (distance & 1));

          if (posSlot < kEndPosModelIndex)

          {

            distance <<= numDirectBits;

            prob = probs + SpecPos;

            {

              UInt32 m = 1;

              distance++;

              do

              {

                REV_BIT_VAR(prob, distance, m);

              }

              while (--numDirectBits);

              distance -= m;

            }

          }

          else

          {

            numDirectBits -= kNumAlignBits;

            do

            {

              NORMALIZE

              range >>= 1;

              {

                UInt32 t;

                code -= range;

                t = (0 - ((UInt32)code >> 31)); /* (UInt32)((Int32)code >> 31) */

                distance = (distance << 1) + (t + 1);

                code += range & t;

              }

              /*

              distance <<= 1;

              if (code >= range)

              {

                code -= range;

                distance |= 1;

              }

              */

            }

            while (--numDirectBits);

            prob = probs + Align;

            distance <<= kNumAlignBits;

            {

              unsigned i = 1;

              REV_BIT_CONST(prob, i, 1);

              REV_BIT_CONST(prob, i, 2);

              REV_BIT_CONST(prob, i, 4);

              REV_BIT_LAST (prob, i, 8);

              distance |= i;

            }

            if (distance == (UInt32)0xFFFFFFFF)

            {

              len = kMatchSpecLenStart;

              state -= kNumStates;

              break;

            }

          }

        }

        rep3 = rep2;

        rep2 = rep1;

        rep1 = rep0;

        rep0 = distance + 1;

        state = (state < kNumStates + kNumLitStates) ? kNumLitStates : kNumLitStates + 3;

        if (distance >= (checkDicSize == 0 ? processedPos: checkDicSize))

        {

          p->dicPos = dicPos;

          return SZ_ERROR_DATA;

        }

      }

      len += kMatchMinLen;

      {

        SizeT rem;

        unsigned curLen;

        SizeT pos;

        if ((rem = limit - dicPos) == 0)

        {

          p->dicPos = dicPos;

          return SZ_ERROR_DATA;

        }

        curLen = ((rem < len) ? (unsigned)rem : len);

        pos = dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0);

        processedPos += (UInt32)curLen;

        len -= curLen;

        if (curLen <= dicBufSize - pos)

        {

          Byte *dest = dic + dicPos;

          ptrdiff_t src = (ptrdiff_t)pos - (ptrdiff_t)dicPos;

          const Byte *lim = dest + curLen;

          dicPos += (SizeT)curLen;

          do

            *(dest) = (Byte)*(dest + src);

          while (++dest != lim);

        }

        else

        {

          do

          {

            dic[dicPos++] = dic[pos];

            if (++pos == dicBufSize)

              pos = 0;

          }

          while (--curLen != 0);

        }

      }

    }

  }

  while (dicPos < limit && buf < bufLimit);

  NORMALIZE;

  p->buf = buf;

  p->range = range;

  p->code = code;

  p->remainLen = (UInt32)len;

  p->dicPos = dicPos;

  p->processedPos = processedPos;

  p->reps[0] = rep0;

  p->reps[1] = rep1;

  p->reps[2] = rep2;

  p->reps[3] = rep3;

  p->state = (UInt32)state;

  return SZ_OK;

}

#endif

static void MY_FAST_CALL LzmaDec_WriteRem(CLzmaDec *p, SizeT limit)

{

  if (p->remainLen != 0 && p->remainLen < kMatchSpecLenStart)

  {

    Byte *dic = p->dic;

    SizeT dicPos = p->dicPos;

    SizeT dicBufSize = p->dicBufSize;

    unsigned len = (unsigned)p->remainLen;

    SizeT rep0 = p->reps[0]; /* we use SizeT to avoid the BUG of VC14 for AMD64 */

    SizeT rem = limit - dicPos;

    if (rem < len)

      len = (unsigned)(rem);

    if (p->checkDicSize == 0 && p->prop.dicSize - p->processedPos <= len)

      p->checkDicSize = p->prop.dicSize;

    p->processedPos += (UInt32)len;

    p->remainLen -= (UInt32)len;

    while (len != 0)

    {

      len--;

      dic[dicPos] = dic[dicPos - rep0 + (dicPos < rep0 ? dicBufSize : 0)];

      dicPos++;

    }

    p->dicPos = dicPos;

  }

}

#define kRange0 0xFFFFFFFF

#define kBound0 ((kRange0 >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1))

#define kBadRepCode (kBound0 + (((kRange0 - kBound0) >> kNumBitModelTotalBits) << (kNumBitModelTotalBits - 1)))

#if kBadRepCode != (0xC0000000 - 0x400)

  #error Stop_Compiling_Bad_LZMA_Check

#endif

static int MY_FAST_CALL LzmaDec_DecodeReal2(CLzmaDec *p, SizeT limit, const Byte *bufLimit, SizeT memlimit)

{

  do

  {

    SizeT limit2 = limit;

    if (p->checkDicSize == 0)

    {

      UInt32 rem = p->prop.dicSize - p->processedPos;

      if (limit - p->dicPos > rem) {

          if (p->dicBufSize < p->prop.dicSize) {

              p->dicBufSize = p->prop.dicSize;

              if (p->dicBufSize > memlimit) {

                  return SZ_ERROR_MEM;

              }

              Byte *tmp = realloc(p->dic, p->dicBufSize);

              if (!tmp) {

                  return SZ_ERROR_MEM;

              }

              p->dic = tmp;

          }

        limit2 = p->dicPos + rem;

        }

      if (p->processedPos == 0)

        if (p->code >= kBadRepCode)

          return SZ_ERROR_DATA;

    }

    RINOK(LZMA_DECODE_REAL(p, limit2, bufLimit));

    if (p->checkDicSize == 0 && p->processedPos >= p->prop.dicSize)

      p->checkDicSize = p->prop.dicSize;

    LzmaDec_WriteRem(p, limit);

  }

  while (p->dicPos < limit && p->buf < bufLimit && p->remainLen < kMatchSpecLenStart);

  return 0;

}

typedef enum

{

  DUMMY_ERROR, /* unexpected end of input stream */

  DUMMY_LIT,

  DUMMY_MATCH,

  DUMMY_REP

} ELzmaDummy;

static ELzmaDummy LzmaDec_TryDummy(const CLzmaDec *p, const Byte *buf, SizeT inSize)

{

  UInt32 range = p->range;

  UInt32 code = p->code;

  const Byte *bufLimit = buf + inSize;

  const CLzmaProb *probs = GET_PROBS;

  unsigned state = (unsigned)p->state;

  ELzmaDummy res;

  {

    const CLzmaProb *prob;

    UInt32 bound;

    unsigned ttt;

    unsigned posState = CALC_POS_STATE(p->processedPos, (1 << p->prop.pb) - 1);

    prob = probs + IsMatch + COMBINED_PS_STATE;

    IF_BIT_0_CHECK(prob)

    {

      UPDATE_0_CHECK

      /* if (bufLimit - buf >= 7) return DUMMY_LIT; */

      prob = probs + Literal;

      if (p->checkDicSize != 0 || p->processedPos != 0)

        prob += ((UInt32)LZMA_LIT_SIZE *

            ((((p->processedPos) & ((1 << (p->prop.lp)) - 1)) << p->prop.lc) +

            (p->dic[(p->dicPos == 0 ? p->dicBufSize : p->dicPos) - 1] >> (8 - p->prop.lc))));

      if (state < kNumLitStates)

      {

        unsigned symbol = 1;

        do { GET_BIT_CHECK(prob + symbol, symbol) } while (symbol < 0x100);

      }

      else

      {

        unsigned matchByte = p->dic[p->dicPos - p->reps[0] +

            (p->dicPos < p->reps[0] ? p->dicBufSize : 0)];

        unsigned offs = 0x100;

        unsigned symbol = 1;

        do

        {

          unsigned bit;

          const CLzmaProb *probLit;

          matchByte += matchByte;

          bit = offs;

          offs &= matchByte;

          probLit = prob + (offs + bit + symbol);

          GET_BIT2_CHECK(probLit, symbol, offs ^= bit; , ; )

        }

        while (symbol < 0x100);

      }

      res = DUMMY_LIT;

    }

    else

    {

      unsigned len;

      UPDATE_1_CHECK;

      prob = probs + IsRep + state;

      IF_BIT_0_CHECK(prob)

      {

        UPDATE_0_CHECK;

        state = 0;

        prob = probs + LenCoder;

        res = DUMMY_MATCH;

      }

      else

      {

        UPDATE_1_CHECK;

        res = DUMMY_REP;

        prob = probs + IsRepG0 + state;

        IF_BIT_0_CHECK(prob)

        {

          UPDATE_0_CHECK;

          prob = probs + IsRep0Long + COMBINED_PS_STATE;

          IF_BIT_0_CHECK(prob)

          {

            UPDATE_0_CHECK;

            NORMALIZE_CHECK;

            return DUMMY_REP;

          }

          else

          {

            UPDATE_1_CHECK;

          }

        }

        else

        {

          UPDATE_1_CHECK;

          prob = probs + IsRepG1 + state;

          IF_BIT_0_CHECK(prob)

          {

            UPDATE_0_CHECK;

          }

          else

          {

            UPDATE_1_CHECK;

            prob = probs + IsRepG2 + state;

            IF_BIT_0_CHECK(prob)

            {

              UPDATE_0_CHECK;

            }

            else

            {

              UPDATE_1_CHECK;

            }

          }

        }

        state = kNumStates;

        prob = probs + RepLenCoder;

      }

      {

        unsigned limit, offset;

        const CLzmaProb *probLen = prob + LenChoice;

        IF_BIT_0_CHECK(probLen)

        {

          UPDATE_0_CHECK;

          probLen = prob + LenLow + GET_LEN_STATE;

          offset = 0;

          limit = 1 << kLenNumLowBits;

        }

        else

        {

          UPDATE_1_CHECK;

          probLen = prob + LenChoice2;

          IF_BIT_0_CHECK(probLen)

          {

            UPDATE_0_CHECK;

            probLen = prob + LenLow + GET_LEN_STATE + (1 << kLenNumLowBits);

            offset = kLenNumLowSymbols;

            limit = 1 << kLenNumLowBits;

          }

          else

          {

            UPDATE_1_CHECK;

            probLen = prob + LenHigh;

            offset = kLenNumLowSymbols * 2;

            limit = 1 << kLenNumHighBits;

          }

        }

        TREE_DECODE_CHECK(probLen, limit, len);

        len += offset;

      }

      if (state < 4)

      {

        unsigned posSlot;

        prob = probs + PosSlot +

            ((len < kNumLenToPosStates - 1 ? len : kNumLenToPosStates - 1) <<

            kNumPosSlotBits);

        TREE_DECODE_CHECK(prob, 1 << kNumPosSlotBits, posSlot);

        if (posSlot >= kStartPosModelIndex)

        {

          unsigned numDirectBits = ((posSlot >> 1) - 1);

          /* if (bufLimit - buf >= 8) return DUMMY_MATCH; */

          if (posSlot < kEndPosModelIndex)

          {

            prob = probs + SpecPos + ((2 | (posSlot & 1)) << numDirectBits);

          }

          else

          {

            numDirectBits -= kNumAlignBits;

            do

            {

              NORMALIZE_CHECK

              range >>= 1;

              code -= range & (((code - range) >> 31) - 1);

              /* if (code >= range) code -= range; */

            }

            while (--numDirectBits);

            prob = probs + Align;

            numDirectBits = kNumAlignBits;

          }

          {