Coverage Report

Created: 2024-07-27 06:12

/src/lzma-fuzz/sdk/C/Ppmd7Dec.c
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Source (jump to first uncovered line)
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/* Ppmd7Dec.c -- PPMdH Decoder
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2018-07-04 : Igor Pavlov : Public domain
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This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
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#include "Precomp.h"
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#include "Ppmd7.h"
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13.5M
#define kTopValue (1 << 24)
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BoolInt Ppmd7z_RangeDec_Init(CPpmd7z_RangeDec *p)
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1.61k
{
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1.61k
  unsigned i;
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1.61k
  p->Code = 0;
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1.61k
  p->Range = 0xFFFFFFFF;
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1.61k
  if (IByteIn_Read(p->Stream) != 0)
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0
    return False;
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8.09k
  for (i = 0; i < 4; i++)
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6.47k
    p->Code = (p->Code << 8) | IByteIn_Read(p->Stream);
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1.61k
  return (p->Code < 0xFFFFFFFF);
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1.61k
}
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15.1M
#define GET_Ppmd7z_RangeDec CPpmd7z_RangeDec *p = CONTAINER_FROM_VTBL(pp, CPpmd7z_RangeDec, vt);
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static UInt32 Range_GetThreshold(const IPpmd7_RangeDec *pp, UInt32 total)
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6.67M
{
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6.67M
  GET_Ppmd7z_RangeDec
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6.67M
  return p->Code / (p->Range /= total);
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6.67M
}
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static void Range_Normalize(CPpmd7z_RangeDec *p)
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8.50M
{
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8.50M
  if (p->Range < kTopValue)
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5.00M
  {
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5.00M
    p->Code = (p->Code << 8) | IByteIn_Read(p->Stream);
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5.00M
    p->Range <<= 8;
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5.00M
    if (p->Range < kTopValue)
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667k
    {
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667k
      p->Code = (p->Code << 8) | IByteIn_Read(p->Stream);
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667k
      p->Range <<= 8;
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667k
    }
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5.00M
  }
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8.50M
}
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static void Range_Decode(const IPpmd7_RangeDec *pp, UInt32 start, UInt32 size)
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6.67M
{
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6.67M
  GET_Ppmd7z_RangeDec
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6.67M
  p->Code -= start * p->Range;
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6.67M
  p->Range *= size;
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6.67M
  Range_Normalize(p);
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6.67M
}
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static UInt32 Range_DecodeBit(const IPpmd7_RangeDec *pp, UInt32 size0)
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1.83M
{
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1.83M
  GET_Ppmd7z_RangeDec
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1.83M
  UInt32 newBound = (p->Range >> 14) * size0;
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1.83M
  UInt32 symbol;
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1.83M
  if (p->Code < newBound)
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1.50M
  {
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1.50M
    symbol = 0;
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1.50M
    p->Range = newBound;
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1.50M
  }
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329k
  else
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329k
  {
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329k
    symbol = 1;
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329k
    p->Code -= newBound;
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329k
    p->Range -= newBound;
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329k
  }
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1.83M
  Range_Normalize(p);
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1.83M
  return symbol;
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1.83M
}
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void Ppmd7z_RangeDec_CreateVTable(CPpmd7z_RangeDec *p)
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1.61k
{
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1.61k
  p->vt.GetThreshold = Range_GetThreshold;
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1.61k
  p->vt.Decode = Range_Decode;
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1.61k
  p->vt.DecodeBit = Range_DecodeBit;
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1.61k
}
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107M
#define MASK(sym) ((signed char *)charMask)[sym]
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int Ppmd7_DecodeSymbol(CPpmd7 *p, const IPpmd7_RangeDec *rc)
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7.95M
{
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7.95M
  size_t charMask[256 / sizeof(size_t)];
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7.95M
  if (p->MinContext->NumStats != 1)
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6.12M
  {
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6.12M
    CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext);
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6.12M
    unsigned i;
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6.12M
    UInt32 count, hiCnt;
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6.12M
    if ((count = rc->GetThreshold(rc, p->MinContext->SummFreq)) < (hiCnt = s->Freq))
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1.44M
    {
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1.44M
      Byte symbol;
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1.44M
      rc->Decode(rc, 0, s->Freq);
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1.44M
      p->FoundState = s;
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1.44M
      symbol = s->Symbol;
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1.44M
      Ppmd7_Update1_0(p);
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1.44M
      return symbol;
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1.44M
    }
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4.68M
    p->PrevSuccess = 0;
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4.68M
    i = p->MinContext->NumStats - 1;
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4.68M
    do
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597M
    {
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597M
      if ((hiCnt += (++s)->Freq) > count)
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4.53M
      {
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4.53M
        Byte symbol;
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4.53M
        rc->Decode(rc, hiCnt - s->Freq, s->Freq);
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4.53M
        p->FoundState = s;
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4.53M
        symbol = s->Symbol;
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4.53M
        Ppmd7_Update1(p);
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4.53M
        return symbol;
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4.53M
      }
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597M
    }
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592M
    while (--i);
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152k
    if (count >= p->MinContext->SummFreq)
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0
      return -2;
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152k
    p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol];
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152k
    rc->Decode(rc, hiCnt, p->MinContext->SummFreq - hiCnt);
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152k
    PPMD_SetAllBitsIn256Bytes(charMask);
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152k
    MASK(s->Symbol) = 0;
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152k
    i = p->MinContext->NumStats - 1;
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486k
    do { MASK((--s)->Symbol) = 0; } while (--i);
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152k
  }
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1.83M
  else
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1.83M
  {
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1.83M
    UInt16 *prob = Ppmd7_GetBinSumm(p);
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1.83M
    if (rc->DecodeBit(rc, *prob) == 0)
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1.50M
    {
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1.50M
      Byte symbol;
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1.50M
      *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
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1.50M
      symbol = (p->FoundState = Ppmd7Context_OneState(p->MinContext))->Symbol;
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1.50M
      Ppmd7_UpdateBin(p);
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1.50M
      return symbol;
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1.50M
    }
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329k
    *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
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329k
    p->InitEsc = PPMD7_kExpEscape[*prob >> 10];
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329k
    PPMD_SetAllBitsIn256Bytes(charMask);
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329k
    MASK(Ppmd7Context_OneState(p->MinContext)->Symbol) = 0;
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329k
    p->PrevSuccess = 0;
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329k
  }
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481k
  for (;;)
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549k
  {
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549k
    CPpmd_State *ps[256], *s;
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549k
    UInt32 freqSum, count, hiCnt;
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549k
    CPpmd_See *see;
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549k
    unsigned i, num, numMasked = p->MinContext->NumStats;
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549k
    do
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769k
    {
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769k
      p->OrderFall++;
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769k
      if (!p->MinContext->Suffix)
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0
        return -1;
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769k
      p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix);
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769k
    }
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769k
    while (p->MinContext->NumStats == numMasked);
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549k
    hiCnt = 0;
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549k
    s = Ppmd7_GetStats(p, p->MinContext);
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549k
    i = 0;
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549k
    num = p->MinContext->NumStats - numMasked;
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549k
    do
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105M
    {
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105M
      int k = (int)(MASK(s->Symbol));
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105M
      hiCnt += (s->Freq & k);
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105M
      ps[i] = s++;
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105M
      i -= k;
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105M
    }
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105M
    while (i != num);
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549k
    see = Ppmd7_MakeEscFreq(p, numMasked, &freqSum);
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549k
    freqSum += hiCnt;
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549k
    count = rc->GetThreshold(rc, freqSum);
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549k
    if (count < hiCnt)
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481k
    {
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481k
      Byte symbol;
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481k
      CPpmd_State **pps = ps;
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39.9M
      for (hiCnt = 0; (hiCnt += (*pps)->Freq) <= count; pps++);
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481k
      s = *pps;
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481k
      rc->Decode(rc, hiCnt - s->Freq, s->Freq);
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481k
      Ppmd_See_Update(see);
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481k
      p->FoundState = s;
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481k
      symbol = s->Symbol;
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481k
      Ppmd7_Update2(p);
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481k
      return symbol;
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481k
    }
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68.3k
    if (count >= freqSum)
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0
      return -2;
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68.3k
    rc->Decode(rc, hiCnt, freqSum - hiCnt);
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68.3k
    see->Summ = (UInt16)(see->Summ + freqSum);
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163k
    do { MASK(ps[--i]->Symbol) = 0; } while (i != 0);
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68.3k
  }
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481k
}