/* LzmaDec.c -- LZMA Decoder
2018-07-04 : Igor Pavlov : Public domain */

#include "Precomp.h"

#ifndef EFIAPI
  #include <string.h>
#endif

/* #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
  )
{
  do {
    SizeT  limit2 = limit;
    if (p->checkDicSize == 0) {
      UInt32  rem = p->prop.dicSize - p->processedPos;
      if (limit - p->dicPos > rem) {
        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;
          }

          {
            unsigned  i = 1;
            unsigned  m = 1;
            do {
              REV_BIT_CHECK (prob, i, m);
            } while (--numDirectBits);
          }
        }
      }
    }
  }

  NORMALIZE_CHECK;
  return res;
}

void
LzmaDec_InitDicAndState (
  CLzmaDec  *p,
  BoolInt   initDic,
  BoolInt   initState
  )
{
  p->remainLen   = kMatchSpecLenStart + 1;
  p->tempBufSize = 0;

  if (initDic) {
    p->processedPos = 0;
    p->checkDicSize = 0;
    p->remainLen    = kMatchSpecLenStart + 2;
  }

  if (initState) {
    p->remainLen = kMatchSpecLenStart + 2;
  }
}

void
LzmaDec_Init (
  CLzmaDec  *p
  )
{
  p->dicPos = 0;
  LzmaDec_InitDicAndState (p, True, True);
}

SRes
LzmaDec_DecodeToDic (
  CLzmaDec         *p,
  SizeT            dicLimit,
  const Byte       *src,
  SizeT            *srcLen,
  ELzmaFinishMode  finishMode,
  ELzmaStatus      *status
  )
{
  SizeT  inSize = *srcLen;

  (*srcLen) = 0;

  *status = LZMA_STATUS_NOT_SPECIFIED;

  if (p->remainLen > kMatchSpecLenStart) {
    for ( ; inSize > 0 && p->tempBufSize < RC_INIT_SIZE; (*srcLen)++, inSize--) {
      p->tempBuf[p->tempBufSize++] = *src++;
    }

    if ((p->tempBufSize != 0) && (p->tempBuf[0] != 0)) {
      return SZ_ERROR_DATA;
    }

    if (p->tempBufSize < RC_INIT_SIZE) {
      *status = LZMA_STATUS_NEEDS_MORE_INPUT;
      return SZ_OK;
    }

    p->code =
      ((UInt32)p->tempBuf[1] << 24)
      | ((UInt32)p->tempBuf[2] << 16)
      | ((UInt32)p->tempBuf[3] << 8)
      | ((UInt32)p->tempBuf[4]);
    p->range       = 0xFFFFFFFF;
    p->tempBufSize = 0;

    if (p->remainLen > kMatchSpecLenStart + 1) {
      SizeT      numProbs = LzmaProps_GetNumProbs (&p->prop);
      SizeT      i;
      CLzmaProb  *probs = p->probs;
      for (i = 0; i < numProbs; i++) {
        probs[i] = kBitModelTotal >> 1;
      }

      p->reps[0] = p->reps[1] = p->reps[2] = p->reps[3] = 1;
      p->state   = 0;
    }

    p->remainLen = 0;
  }

  LzmaDec_WriteRem (p, dicLimit);

  while (p->remainLen != kMatchSpecLenStart) {
    int  checkEndMarkNow = 0;

    if (p->dicPos >= dicLimit) {
      if ((p->remainLen == 0) && (p->code == 0)) {
        *status = LZMA_STATUS_MAYBE_FINISHED_WITHOUT_MARK;
        return SZ_OK;
      }

      if (finishMode == LZMA_FINISH_ANY) {
        *status = LZMA_STATUS_NOT_FINISHED;
        return SZ_OK;
      }

      if (p->remainLen != 0) {
        *status = LZMA_STATUS_NOT_FINISHED;
        return SZ_ERROR_DATA;
      }

      checkEndMarkNow = 1;
    }

    if (p->tempBufSize == 0) {
      SizeT       processed;
      const Byte  *bufLimit;
      if ((inSize < LZMA_REQUIRED_INPUT_MAX) || checkEndMarkNow) {
        int  dummyRes = LzmaDec_TryDummy (p, src, inSize);
        if (dummyRes == DUMMY_ERROR) {
          memcpy (p->tempBuf, src, inSize);
          p->tempBufSize = (unsigned)inSize;
          (*srcLen)     += inSize;
          *status        = LZMA_STATUS_NEEDS_MORE_INPUT;
          return SZ_OK;
        }

        if (checkEndMarkNow && (dummyRes != DUMMY_MATCH)) {
          *status = LZMA_STATUS_NOT_FINISHED;
          return SZ_ERROR_DATA;
        }

        bufLimit = src;
      } else {
        bufLimit = src + inSize - LZMA_REQUIRED_INPUT_MAX;
      }

      p->buf = src;
      if (LzmaDec_DecodeReal2 (p, dicLimit, bufLimit) != 0) {
        return SZ_ERROR_DATA;
      }

      processed  = (SizeT)(p->buf - src);
      (*srcLen) += processed;
      src       += processed;
      inSize    -= processed;
    } else {
      unsigned  rem = p->tempBufSize, lookAhead = 0;
      while (rem < LZMA_REQUIRED_INPUT_MAX && lookAhead < inSize) {
        p->tempBuf[rem++] = src[lookAhead++];
      }

      p->tempBufSize = rem;
      if ((rem < LZMA_REQUIRED_INPUT_MAX) || checkEndMarkNow) {
        int  dummyRes = LzmaDec_TryDummy (p, p->tempBuf, (SizeT)rem);
        if (dummyRes == DUMMY_ERROR) {
          (*srcLen) += (SizeT)lookAhead;
          *status    = LZMA_STATUS_NEEDS_MORE_INPUT;
          return SZ_OK;
        }

        if (checkEndMarkNow && (dummyRes != DUMMY_MATCH)) {
          *status = LZMA_STATUS_NOT_FINISHED;
          return SZ_ERROR_DATA;
        }
      }

      p->buf = p->tempBuf;
      if (LzmaDec_DecodeReal2 (p, dicLimit, p->buf) != 0) {
        return SZ_ERROR_DATA;
      }

      {
        unsigned  kkk = (unsigned)(p->buf - p->tempBuf);
        if (rem < kkk) {
          return SZ_ERROR_FAIL;   /* some internal error */
        }

        rem -= kkk;
        if (lookAhead < rem) {
          return SZ_ERROR_FAIL;   /* some internal error */
        }

        lookAhead -= rem;
      }
      (*srcLen)     += (SizeT)lookAhead;
      src           += lookAhead;
      inSize        -= (SizeT)lookAhead;
      p->tempBufSize = 0;
    }
  }

  if (p->code != 0) {
    return SZ_ERROR_DATA;
  }

  *status = LZMA_STATUS_FINISHED_WITH_MARK;
  return SZ_OK;
}

SRes
LzmaDec_DecodeToBuf (
  CLzmaDec         *p,
  Byte             *dest,
  SizeT            *destLen,
  const Byte       *src,
  SizeT            *srcLen,
  ELzmaFinishMode  finishMode,
  ELzmaStatus      *status
  )
{
  SizeT  outSize = *destLen;
  SizeT  inSize  = *srcLen;

  *srcLen = *destLen = 0;
  for ( ; ;) {
    SizeT            inSizeCur = inSize, outSizeCur, dicPos;
    ELzmaFinishMode  curFinishMode;
    SRes             res;
    if (p->dicPos == p->dicBufSize) {
      p->dicPos = 0;
    }

    dicPos = p->dicPos;
    if (outSize > p->dicBufSize - dicPos) {
      outSizeCur    = p->dicBufSize;
      curFinishMode = LZMA_FINISH_ANY;
    } else {
      outSizeCur    = dicPos + outSize;
      curFinishMode = finishMode;
    }

    res        = LzmaDec_DecodeToDic (p, outSizeCur, src, &inSizeCur, curFinishMode, status);
    src       += inSizeCur;
    inSize    -= inSizeCur;
    *srcLen   += inSizeCur;
    outSizeCur = p->dicPos - dicPos;
    memcpy (dest, p->dic + dicPos, outSizeCur);
    dest     += outSizeCur;
    outSize  -= outSizeCur;
    *destLen += outSizeCur;
    if (res != 0) {
      return res;
    }

    if ((outSizeCur == 0) || (outSize == 0)) {
      return SZ_OK;
    }
  }
}

void
LzmaDec_FreeProbs (
  CLzmaDec     *p,
  ISzAllocPtr  alloc
  )
{
  ISzAlloc_Free (alloc, p->probs);
  p->probs = NULL;
}

static void
LzmaDec_FreeDict (
  CLzmaDec     *p,
  ISzAllocPtr  alloc
  )
{
  ISzAlloc_Free (alloc, p->dic);
  p->dic = NULL;
}

void
LzmaDec_Free (
  CLzmaDec     *p,
  ISzAllocPtr  alloc
  )
{
  LzmaDec_FreeProbs (p, alloc);
  LzmaDec_FreeDict (p, alloc);
}

SRes
LzmaProps_Decode (
  CLzmaProps  *p,
  const Byte  *data,
  unsigned    size
  )
{
  UInt32  dicSize;
  Byte    d;

  if (size < LZMA_PROPS_SIZE) {
    return SZ_ERROR_UNSUPPORTED;
  } else {
    dicSize = data[1] | ((UInt32)data[2] << 8) | ((UInt32)data[3] << 16) | ((UInt32)data[4] << 24);
  }

  if (dicSize < LZMA_DIC_MIN) {
    dicSize = LZMA_DIC_MIN;
  }

  p->dicSize = dicSize;

  d = data[0];
  if (d >= (9 * 5 * 5)) {
    return SZ_ERROR_UNSUPPORTED;
  }

  p->lc = (Byte)(d % 9);
  d    /= 9;
  p->pb = (Byte)(d / 5);
  p->lp = (Byte)(d % 5);

  return SZ_OK;
}

static SRes
LzmaDec_AllocateProbs2 (
  CLzmaDec          *p,
  const CLzmaProps  *propNew,
  ISzAllocPtr       alloc
  )
{
  UInt32  numProbs = LzmaProps_GetNumProbs (propNew);

  if (!p->probs || (numProbs != p->numProbs)) {
    LzmaDec_FreeProbs (p, alloc);
    p->probs = (CLzmaProb *)ISzAlloc_Alloc (alloc, numProbs * sizeof (CLzmaProb));
    if (!p->probs) {
      return SZ_ERROR_MEM;
    }

    p->probs_1664 = p->probs + 1664;
    p->numProbs   = numProbs;
  }

  return SZ_OK;
}

SRes
LzmaDec_AllocateProbs (
  CLzmaDec     *p,
  const Byte   *props,
  unsigned     propsSize,
  ISzAllocPtr  alloc
  )
{
  CLzmaProps  propNew;

  RINOK (LzmaProps_Decode (&propNew, props, propsSize));
  RINOK (LzmaDec_AllocateProbs2 (p, &propNew, alloc));
  p->prop = propNew;
  return SZ_OK;
}

SRes
LzmaDec_Allocate (
  CLzmaDec     *p,
  const Byte   *props,
  unsigned     propsSize,
  ISzAllocPtr  alloc
  )
{
  CLzmaProps  propNew;
  SizeT       dicBufSize;

  RINOK (LzmaProps_Decode (&propNew, props, propsSize));
  RINOK (LzmaDec_AllocateProbs2 (p, &propNew, alloc));

  {
    UInt32  dictSize = propNew.dicSize;
    SizeT   mask     = ((UInt32)1 << 12) - 1;
    if (dictSize >= ((UInt32)1 << 30)) {
      mask = ((UInt32)1 << 22) - 1;
    } else if (dictSize >= ((UInt32)1 << 22)) {
      mask = ((UInt32)1 << 20) - 1;
    }

    dicBufSize = ((SizeT)dictSize + mask) & ~mask;
    if (dicBufSize < dictSize) {
      dicBufSize = dictSize;
    }
  }

  if (!p->dic || (dicBufSize != p->dicBufSize)) {
    LzmaDec_FreeDict (p, alloc);
    p->dic = (Byte *)ISzAlloc_Alloc (alloc, dicBufSize);
    if (!p->dic) {
      LzmaDec_FreeProbs (p, alloc);
      return SZ_ERROR_MEM;
    }
  }

  p->dicBufSize = dicBufSize;
  p->prop       = propNew;
  return SZ_OK;
}

SRes
LzmaDecode (
  Byte             *dest,
  SizeT            *destLen,
  const Byte       *src,
  SizeT            *srcLen,
  const Byte       *propData,
  unsigned         propSize,
  ELzmaFinishMode  finishMode,
  ELzmaStatus      *status,
  ISzAllocPtr      alloc
  )
{
  CLzmaDec  p;
  SRes      res;
  SizeT     outSize = *destLen, inSize = *srcLen;

  *destLen = *srcLen = 0;
  *status  = LZMA_STATUS_NOT_SPECIFIED;
  if (inSize < RC_INIT_SIZE) {
    return SZ_ERROR_INPUT_EOF;
  }

  LzmaDec_Construct (&p);
  RINOK (LzmaDec_AllocateProbs (&p, propData, propSize, alloc));
  p.dic        = dest;
  p.dicBufSize = outSize;
  LzmaDec_Init (&p);
  *srcLen  = inSize;
  res      = LzmaDec_DecodeToDic (&p, outSize, src, srcLen, finishMode, status);
  *destLen = p.dicPos;
  if ((res == SZ_OK) && (*status == LZMA_STATUS_NEEDS_MORE_INPUT)) {
    res = SZ_ERROR_INPUT_EOF;
  }

  LzmaDec_FreeProbs (&p, alloc);
  return res;
}
