'21.07'21.07

1 files changed, 1537 insertions, 0 deletions

diff --git a/C/Ppmd8.c b/C/Ppmd8.c
new file mode 100644
index 0000000..fda8b88
--- /dev/null
+++ b/C/Ppmd8.c
@@ -0,0 +1,1537 @@
+/* Ppmd8.c -- PPMdI codec
+2021-04-13 : Igor Pavlov : Public domain
+This code is based on PPMd var.I (2002): Dmitry Shkarin : Public domain */
+
+#include "Precomp.h"
+
+#include <string.h>
+
+#include "Ppmd8.h"
+
+
+
+
+MY_ALIGN(16)
+static const Byte PPMD8_kExpEscape[16] = { 25, 14, 9, 7, 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 2, 2 };
+MY_ALIGN(16)
+static const UInt16 kInitBinEsc[] = { 0x3CDD, 0x1F3F, 0x59BF, 0x48F3, 0x64A1, 0x5ABC, 0x6632, 0x6051};
+
+#define MAX_FREQ 124
+#define UNIT_SIZE 12
+
+#define U2B(nu) ((UInt32)(nu) * UNIT_SIZE)
+#define U2I(nu) (p->Units2Indx[(size_t)(nu) - 1])
+#define I2U(indx) ((unsigned)p->Indx2Units[indx])
+
+
+#define REF(ptr) Ppmd_GetRef(p, ptr)
+
+#define STATS_REF(ptr) ((CPpmd_State_Ref)REF(ptr))
+
+#define CTX(ref) ((CPpmd8_Context *)Ppmd8_GetContext(p, ref))
+#define STATS(ctx) Ppmd8_GetStats(p, ctx)
+#define ONE_STATE(ctx) Ppmd8Context_OneState(ctx)
+#define SUFFIX(ctx) CTX((ctx)->Suffix)
+
+typedef CPpmd8_Context * CTX_PTR;
+
+struct CPpmd8_Node_;
+
+typedef Ppmd_Ref_Type(struct CPpmd8_Node_) CPpmd8_Node_Ref;
+
+typedef struct CPpmd8_Node_
+{
+  UInt32 Stamp;
+  
+  CPpmd8_Node_Ref Next;
+  UInt32 NU;
+} CPpmd8_Node;
+
+#define NODE(r)  Ppmd_GetPtr_Type(p, r, CPpmd8_Node)
+
+void Ppmd8_Construct(CPpmd8 *p)
+{
+  unsigned i, k, m;
+
+  p->Base = NULL;
+
+  for (i = 0, k = 0; i < PPMD_NUM_INDEXES; i++)
+  {
+    unsigned step = (i >= 12 ? 4 : (i >> 2) + 1);
+    do { p->Units2Indx[k++] = (Byte)i; } while (--step);
+    p->Indx2Units[i] = (Byte)k;
+  }
+
+  p->NS2BSIndx[0] = (0 << 1);
+  p->NS2BSIndx[1] = (1 << 1);
+  memset(p->NS2BSIndx + 2, (2 << 1), 9);
+  memset(p->NS2BSIndx + 11, (3 << 1), 256 - 11);
+
+  for (i = 0; i < 5; i++)
+    p->NS2Indx[i] = (Byte)i;
+  
+  for (m = i, k = 1; i < 260; i++)
+  {
+    p->NS2Indx[i] = (Byte)m;
+    if (--k == 0)
+      k = (++m) - 4;
+  }
+
+  memcpy(p->ExpEscape, PPMD8_kExpEscape, 16);
+}
+
+
+void Ppmd8_Free(CPpmd8 *p, ISzAllocPtr alloc)
+{
+  ISzAlloc_Free(alloc, p->Base);
+  p->Size = 0;
+  p->Base = NULL;
+}
+
+
+BoolInt Ppmd8_Alloc(CPpmd8 *p, UInt32 size, ISzAllocPtr alloc)
+{
+  if (!p->Base || p->Size != size)
+  {
+    Ppmd8_Free(p, alloc);
+    p->AlignOffset = (4 - size) & 3;
+    if ((p->Base = (Byte *)ISzAlloc_Alloc(alloc, p->AlignOffset + size)) == NULL)
+      return False;
+    p->Size = size;
+  }
+  return True;
+}
+
+
+
+// ---------- Internal Memory Allocator ----------
+
+
+
+
+
+
+#define EMPTY_NODE 0xFFFFFFFF
+
+
+static void InsertNode(CPpmd8 *p, void *node, unsigned indx)
+{
+  ((CPpmd8_Node *)node)->Stamp = EMPTY_NODE;
+  ((CPpmd8_Node *)node)->Next = (CPpmd8_Node_Ref)p->FreeList[indx];
+  ((CPpmd8_Node *)node)->NU = I2U(indx);
+  p->FreeList[indx] = REF(node);
+  p->Stamps[indx]++;
+}
+
+
+static void *RemoveNode(CPpmd8 *p, unsigned indx)
+{
+  CPpmd8_Node *node = NODE((CPpmd8_Node_Ref)p->FreeList[indx]);
+  p->FreeList[indx] = node->Next;
+  p->Stamps[indx]--;
+
+  return node;
+}
+
+
+static void SplitBlock(CPpmd8 *p, void *ptr, unsigned oldIndx, unsigned newIndx)
+{
+  unsigned i, nu = I2U(oldIndx) - I2U(newIndx);
+  ptr = (Byte *)ptr + U2B(I2U(newIndx));
+  if (I2U(i = U2I(nu)) != nu)
+  {
+    unsigned k = I2U(--i);
+    InsertNode(p, ((Byte *)ptr) + U2B(k), nu - k - 1);
+  }
+  InsertNode(p, ptr, i);
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+static void GlueFreeBlocks(CPpmd8 *p)
+{
+  /*
+  we use first UInt32 field of 12-bytes UNITs as record type stamp
+    CPpmd_State    { Byte Symbol; Byte Freq; : Freq != 0xFF
+    CPpmd8_Context { Byte NumStats; Byte Flags; UInt16 SummFreq;  : Flags != 0xFF ???
+    CPpmd8_Node    { UInt32 Stamp            : Stamp == 0xFFFFFFFF for free record
+                                             : Stamp == 0 for guard
+    Last 12-bytes UNIT in array is always contains 12-bytes order-0 CPpmd8_Context record
+  */
+  CPpmd8_Node_Ref n;
+
+  p->GlueCount = 1 << 13;
+  memset(p->Stamps, 0, sizeof(p->Stamps));
+  
+  /* we set guard NODE at LoUnit */
+  if (p->LoUnit != p->HiUnit)
+    ((CPpmd8_Node *)(void *)p->LoUnit)->Stamp = 0;
+
+  {
+    /* Glue free blocks */
+    CPpmd8_Node_Ref *prev = &n;
+    unsigned i;
+    for (i = 0; i < PPMD_NUM_INDEXES; i++)
+    {
+
+      CPpmd8_Node_Ref next = (CPpmd8_Node_Ref)p->FreeList[i];
+      p->FreeList[i] = 0;
+      while (next != 0)
+      {
+        CPpmd8_Node *node = NODE(next);
+        UInt32 nu = node->NU;
+        *prev = next;
+        next = node->Next;
+        if (nu != 0)
+        {
+          CPpmd8_Node *node2;
+          prev = &(node->Next);
+          while ((node2 = node + nu)->Stamp == EMPTY_NODE)
+          {
+            nu += node2->NU;
+            node2->NU = 0;
+            node->NU = nu;
+          }
+        }
+      }
+    }
+
+    *prev = 0;
+  }
+
+
+
+  
+
+
+
+
+
+
+  
+
+  
+  
+  
+  
+  
+  
+  
+  
+  /* Fill lists of free blocks */
+  while (n != 0)
+  {
+    CPpmd8_Node *node = NODE(n);
+    UInt32 nu = node->NU;
+    unsigned i;
+    n = node->Next;
+    if (nu == 0)
+      continue;
+    for (; nu > 128; nu -= 128, node += 128)
+      InsertNode(p, node, PPMD_NUM_INDEXES - 1);
+    if (I2U(i = U2I(nu)) != nu)
+    {
+      unsigned k = I2U(--i);
+      InsertNode(p, node + k, (unsigned)nu - k - 1);
+    }
+    InsertNode(p, node, i);
+  }
+}
+
+
+MY_NO_INLINE
+static void *AllocUnitsRare(CPpmd8 *p, unsigned indx)
+{
+  unsigned i;
+  
+  if (p->GlueCount == 0)
+  {
+    GlueFreeBlocks(p);
+    if (p->FreeList[indx] != 0)
+      return RemoveNode(p, indx);
+  }
+  
+  i = indx;
+  
+  do
+  {
+    if (++i == PPMD_NUM_INDEXES)
+    {
+      UInt32 numBytes = U2B(I2U(indx));
+      Byte *us = p->UnitsStart;
+      p->GlueCount--;
+      return ((UInt32)(us - p->Text) > numBytes) ? (p->UnitsStart = us - numBytes) : (NULL);
+    }
+  }
+  while (p->FreeList[i] == 0);
+  
+  {
+    void *block = RemoveNode(p, i);
+    SplitBlock(p, block, i, indx);
+    return block;
+  }
+}
+
+
+static void *AllocUnits(CPpmd8 *p, unsigned indx)
+{
+  if (p->FreeList[indx] != 0)
+    return RemoveNode(p, indx);
+  {
+    UInt32 numBytes = U2B(I2U(indx));
+    Byte *lo = p->LoUnit;
+    if ((UInt32)(p->HiUnit - lo) >= numBytes)
+    {
+      p->LoUnit = lo + numBytes;
+      return lo;
+    }
+  }
+  return AllocUnitsRare(p, indx);
+}
+
+
+#define MyMem12Cpy(dest, src, num) \
+  { UInt32 *d = (UInt32 *)dest; const UInt32 *z = (const UInt32 *)src; UInt32 n = num; \
+    do { d[0] = z[0]; d[1] = z[1]; d[2] = z[2]; z += 3; d += 3; } while (--n); }
+
+
+
+static void *ShrinkUnits(CPpmd8 *p, void *oldPtr, unsigned oldNU, unsigned newNU)
+{
+  unsigned i0 = U2I(oldNU);
+  unsigned i1 = U2I(newNU);
+  if (i0 == i1)
+    return oldPtr;
+  if (p->FreeList[i1] != 0)
+  {
+    void *ptr = RemoveNode(p, i1);
+    MyMem12Cpy(ptr, oldPtr, newNU);
+    InsertNode(p, oldPtr, i0);
+    return ptr;
+  }
+  SplitBlock(p, oldPtr, i0, i1);
+  return oldPtr;
+}
+
+
+static void FreeUnits(CPpmd8 *p, void *ptr, unsigned nu)
+{
+  InsertNode(p, ptr, U2I(nu));
+}
+
+
+static void SpecialFreeUnit(CPpmd8 *p, void *ptr)
+{
+  if ((Byte *)ptr != p->UnitsStart)
+    InsertNode(p, ptr, 0);
+  else
+  {
+    #ifdef PPMD8_FREEZE_SUPPORT
+    *(UInt32 *)ptr = EMPTY_NODE; /* it's used for (Flags == 0xFF) check in RemoveBinContexts() */
+    #endif
+    p->UnitsStart += UNIT_SIZE;
+  }
+}
+
+
+/*
+static void *MoveUnitsUp(CPpmd8 *p, void *oldPtr, unsigned nu)
+{
+  unsigned indx = U2I(nu);
+  void *ptr;
+  if ((Byte *)oldPtr > p->UnitsStart + (1 << 14) || REF(oldPtr) > p->FreeList[indx])
+    return oldPtr;
+  ptr = RemoveNode(p, indx);
+  MyMem12Cpy(ptr, oldPtr, nu);
+  if ((Byte *)oldPtr != p->UnitsStart)
+    InsertNode(p, oldPtr, indx);
+  else
+    p->UnitsStart += U2B(I2U(indx));
+  return ptr;
+}
+*/
+
+static void ExpandTextArea(CPpmd8 *p)
+{
+  UInt32 count[PPMD_NUM_INDEXES];
+  unsigned i;
+ 
+  memset(count, 0, sizeof(count));
+  if (p->LoUnit != p->HiUnit)
+    ((CPpmd8_Node *)(void *)p->LoUnit)->Stamp = 0;
+  
+  {
+    CPpmd8_Node *node = (CPpmd8_Node *)(void *)p->UnitsStart;
+    while (node->Stamp == EMPTY_NODE)
+    {
+      UInt32 nu = node->NU;
+      node->Stamp = 0;
+      count[U2I(nu)]++;
+      node += nu;
+    }
+    p->UnitsStart = (Byte *)node;
+  }
+  
+  for (i = 0; i < PPMD_NUM_INDEXES; i++)
+  {
+    UInt32 cnt = count[i];
+    if (cnt == 0)
+      continue;
+    {
+      CPpmd8_Node_Ref *prev = (CPpmd8_Node_Ref *)&p->FreeList[i];
+      CPpmd8_Node_Ref n = *prev;
+      p->Stamps[i] -= cnt;
+      for (;;)
+      {
+        CPpmd8_Node *node = NODE(n);
+        n = node->Next;
+        if (node->Stamp != 0)
+        {
+          prev = &node->Next;
+          continue;
+        }
+        *prev = n;
+        if (--cnt == 0)
+          break;
+      }
+    }
+  }
+}
+
+
+#define SUCCESSOR(p) Ppmd_GET_SUCCESSOR(p)
+static void SetSuccessor(CPpmd_State *p, CPpmd_Void_Ref v)
+{
+  Ppmd_SET_SUCCESSOR(p, v);
+}
+
+#define RESET_TEXT(offs) { p->Text = p->Base + p->AlignOffset + (offs); }
+
+MY_NO_INLINE
+static
+void RestartModel(CPpmd8 *p)
+{
+  unsigned i, k, m;
+
+  memset(p->FreeList, 0, sizeof(p->FreeList));
+  memset(p->Stamps, 0, sizeof(p->Stamps));
+  RESET_TEXT(0);
+  p->HiUnit = p->Text + p->Size;
+  p->LoUnit = p->UnitsStart = p->HiUnit - p->Size / 8 / UNIT_SIZE * 7 * UNIT_SIZE;
+  p->GlueCount = 0;
+
+  p->OrderFall = p->MaxOrder;
+  p->RunLength = p->InitRL = -(Int32)((p->MaxOrder < 12) ? p->MaxOrder : 12) - 1;
+  p->PrevSuccess = 0;
+
+  {
+    CPpmd8_Context *mc = (CTX_PTR)(void *)(p->HiUnit -= UNIT_SIZE); /* AllocContext(p); */
+    CPpmd_State *s = (CPpmd_State *)p->LoUnit; /* AllocUnits(p, PPMD_NUM_INDEXES - 1); */
+    
+    p->LoUnit += U2B(256 / 2);
+    p->MaxContext = p->MinContext = mc;
+    p->FoundState = s;
+    mc->Flags = 0;
+    mc->NumStats = 256 - 1;
+    mc->Union2.SummFreq = 256 + 1;
+    mc->Union4.Stats = REF(s);
+    mc->Suffix = 0;
+
+    for (i = 0; i < 256; i++, s++)
+    {
+      s->Symbol = (Byte)i;
+      s->Freq = 1;
+      SetSuccessor(s, 0);
+    }
+  }
+
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  for (i = m = 0; m < 25; m++)
+  {
+    while (p->NS2Indx[i] == m)
+      i++;
+    for (k = 0; k < 8; k++)
+    {
+      unsigned r;
+      UInt16 *dest = p->BinSumm[m] + k;
+      UInt16 val = (UInt16)(PPMD_BIN_SCALE - kInitBinEsc[k] / (i + 1));
+      for (r = 0; r < 64; r += 8)
+        dest[r] = val;
+    }
+  }
+
+  for (i = m = 0; m < 24; m++)
+  {
+    unsigned summ;
+    CPpmd_See *s;
+    while (p->NS2Indx[(size_t)i + 3] == m + 3)
+      i++;
+    s = p->See[m];
+    summ = ((2 * i + 5) << (PPMD_PERIOD_BITS - 4));
+    for (k = 0; k < 32; k++, s++)
+    {
+      s->Summ = (UInt16)summ;
+      s->Shift = (PPMD_PERIOD_BITS - 4);
+      s->Count = 7;
+    }
+  }
+
+  p->DummySee.Summ = 0; /* unused */
+  p->DummySee.Shift = PPMD_PERIOD_BITS;
+  p->DummySee.Count = 64; /* unused */
+}
+
+
+void Ppmd8_Init(CPpmd8 *p, unsigned maxOrder, unsigned restoreMethod)
+{
+  p->MaxOrder = maxOrder;
+  p->RestoreMethod = restoreMethod;
+  RestartModel(p);
+}
+
+
+#define FLAG_RESCALED  (1 << 2)
+// #define FLAG_SYM_HIGH  (1 << 3)
+#define FLAG_PREV_HIGH (1 << 4)
+
+#define HiBits_Prepare(sym) ((unsigned)(sym) + 0xC0)
+
+#define HiBits_Convert_3(flags) (((flags) >> (8 - 3)) & (1 << 3))
+#define HiBits_Convert_4(flags) (((flags) >> (8 - 4)) & (1 << 4))
+
+#define PPMD8_HiBitsFlag_3(sym) HiBits_Convert_3(HiBits_Prepare(sym))
+#define PPMD8_HiBitsFlag_4(sym) HiBits_Convert_4(HiBits_Prepare(sym))
+
+// #define PPMD8_HiBitsFlag_3(sym) (0x08 * ((sym) >= 0x40))
+// #define PPMD8_HiBitsFlag_4(sym) (0x10 * ((sym) >= 0x40))
+
+/*
+Refresh() is called when we remove some symbols (successors) in context.
+It increases Escape_Freq for sum of all removed symbols.
+*/
+
+static void Refresh(CPpmd8 *p, CTX_PTR ctx, unsigned oldNU, unsigned scale)
+{
+  unsigned i = ctx->NumStats, escFreq, sumFreq, flags;
+  CPpmd_State *s = (CPpmd_State *)ShrinkUnits(p, STATS(ctx), oldNU, (i + 2) >> 1);
+  ctx->Union4.Stats = REF(s);
+
+  // #ifdef PPMD8_FREEZE_SUPPORT
+  /*
+    (ctx->Union2.SummFreq >= ((UInt32)1 << 15)) can be in FREEZE mode for some files.
+    It's not good for range coder. So new versions of support fix:
+       -   original PPMdI code rev.1
+       +   original PPMdI code rev.2
+       -   7-Zip default ((PPMD8_FREEZE_SUPPORT is not defined)
+       +   7-Zip (p->RestoreMethod >= PPMD8_RESTORE_METHOD_FREEZE)
+    if we       use that fixed line, we can lose compatibility with some files created before fix
+    if we don't use that fixed line, the program can work incorrectly in FREEZE mode in rare case.
+  */
+  // if (p->RestoreMethod >= PPMD8_RESTORE_METHOD_FREEZE)
+  {
+    scale |= (ctx->Union2.SummFreq >= ((UInt32)1 << 15));
+  }
+  // #endif
+
+
+
+  flags = HiBits_Prepare(s->Symbol);
+  {
+    unsigned freq = s->Freq;
+    escFreq = ctx->Union2.SummFreq - freq;
+    freq = (freq + scale) >> scale;
+    sumFreq = freq;
+    s->Freq = (Byte)freq;
+  }
+ 
+  do
+  {
+    unsigned freq = (++s)->Freq;
+    escFreq -= freq;
+    freq = (freq + scale) >> scale;
+    sumFreq += freq;
+    s->Freq = (Byte)freq;
+    flags |= HiBits_Prepare(s->Symbol);
+  }
+  while (--i);
+  
+  ctx->Union2.SummFreq = (UInt16)(sumFreq + ((escFreq + scale) >> scale));
+  ctx->Flags = (Byte)((ctx->Flags & (FLAG_PREV_HIGH + FLAG_RESCALED * scale)) + HiBits_Convert_3(flags));
+}
+
+
+static void SwapStates(CPpmd_State *t1, CPpmd_State *t2)
+{
+  CPpmd_State tmp = *t1;
+  *t1 = *t2;
+  *t2 = tmp;
+}
+
+
+/*
+CutOff() reduces contexts:
+  It conversts Successors at MaxOrder to another Contexts to NULL-Successors
+  It removes RAW-Successors and NULL-Successors that are not Order-0
+      and it removes contexts when it has no Successors.
+  if the (Union4.Stats) is close to (UnitsStart), it moves it up.
+*/
+
+static CPpmd_Void_Ref CutOff(CPpmd8 *p, CTX_PTR ctx, unsigned order)
+{
+  int ns = ctx->NumStats;
+  unsigned nu;
+  CPpmd_State *stats;
+  
+  if (ns == 0)
+  {
+    CPpmd_State *s = ONE_STATE(ctx);
+    CPpmd_Void_Ref successor = SUCCESSOR(s);
+    if ((Byte *)Ppmd8_GetPtr(p, successor) >= p->UnitsStart)
+    {
+      if (order < p->MaxOrder)
+        successor = CutOff(p, CTX(successor), order + 1);
+      else
+        successor = 0;
+      SetSuccessor(s, successor);
+      if (successor || order <= 9) /* O_BOUND */
+        return REF(ctx);
+    }
+    SpecialFreeUnit(p, ctx);
+    return 0;
+  }
+
+  nu = ((unsigned)ns + 2) >> 1;
+  // ctx->Union4.Stats = STATS_REF(MoveUnitsUp(p, STATS(ctx), nu));
+  {
+    unsigned indx = U2I(nu);
+    stats = STATS(ctx);
+
+    if ((UInt32)((Byte *)stats - p->UnitsStart) <= (1 << 14)
+        && (CPpmd_Void_Ref)ctx->Union4.Stats <= p->FreeList[indx])
+    {
+      void *ptr = RemoveNode(p, indx);
+      ctx->Union4.Stats = STATS_REF(ptr);
+      MyMem12Cpy(ptr, (const void *)stats, nu);
+      if ((Byte *)stats != p->UnitsStart)
+        InsertNode(p, stats, indx);
+      else
+        p->UnitsStart += U2B(I2U(indx));
+      stats = ptr;
+    }
+  }
+
+  {
+    CPpmd_State *s = stats + (unsigned)ns;
+    do
+    {
+      CPpmd_Void_Ref successor = SUCCESSOR(s);
+      if ((Byte *)Ppmd8_GetPtr(p, successor) < p->UnitsStart)
+      {
+        CPpmd_State *s2 = stats + (unsigned)(ns--);
+        if (order)
+        {
+          if (s != s2)
+            *s = *s2;
+        }
+        else
+        {
+          SwapStates(s, s2);
+          SetSuccessor(s2, 0);
+        }
+      }
+      else
+      {
+        if (order < p->MaxOrder)
+          SetSuccessor(s, CutOff(p, CTX(successor), order + 1));
+        else
+          SetSuccessor(s, 0);
+      }
+    }
+    while (--s >= stats);
+  }
+  
+  if (ns != ctx->NumStats && order)
+  {
+    if (ns < 0)
+    {
+      FreeUnits(p, stats, nu);
+      SpecialFreeUnit(p, ctx);
+      return 0;
+    }
+    ctx->NumStats = (Byte)ns;
+    if (ns == 0)
+    {
+      const Byte sym = stats->Symbol;
+      ctx->Flags = (Byte)((ctx->Flags & FLAG_PREV_HIGH) + PPMD8_HiBitsFlag_3(sym));
+      // *ONE_STATE(ctx) = *stats;
+      ctx->Union2.State2.Symbol = sym;
+      ctx->Union2.State2.Freq = (Byte)(((unsigned)stats->Freq + 11) >> 3);
+      ctx->Union4.State4.Successor_0 = stats->Successor_0;
+      ctx->Union4.State4.Successor_1 = stats->Successor_1;
+      FreeUnits(p, stats, nu);
+    }
+    else
+    {
+      Refresh(p, ctx, nu, ctx->Union2.SummFreq > 16 * (unsigned)ns);
+    }
+  }
+  
+  return REF(ctx);
+}
+
+
+
+#ifdef PPMD8_FREEZE_SUPPORT
+
+/*
+RemoveBinContexts()
+  It conversts Successors at MaxOrder to another Contexts to NULL-Successors
+  It changes RAW-Successors to NULL-Successors
+  removes Bin Context without Successor, if suffix of that context is also binary.
+*/
+
+static CPpmd_Void_Ref RemoveBinContexts(CPpmd8 *p, CTX_PTR ctx, unsigned order)
+{
+  if (!ctx->NumStats)
+  {
+    CPpmd_State *s = ONE_STATE(ctx);
+    CPpmd_Void_Ref successor = SUCCESSOR(s);
+    if ((Byte *)Ppmd8_GetPtr(p, successor) >= p->UnitsStart && order < p->MaxOrder)
+      successor = RemoveBinContexts(p, CTX(successor), order + 1);
+    else
+      successor = 0;
+    SetSuccessor(s, successor);
+    /* Suffix context can be removed already, since different (high-order)
+       Successors may refer to same context. So we check Flags == 0xFF (Stamp == EMPTY_NODE) */
+    if (!successor && (!SUFFIX(ctx)->NumStats || SUFFIX(ctx)->Flags == 0xFF))
+    {
+      FreeUnits(p, ctx, 1);
+      return 0;
+    }
+  }
+  else
+  {
+    CPpmd_State *s = STATS(ctx) + ctx->NumStats;
+    do
+    {
+      CPpmd_Void_Ref successor = SUCCESSOR(s);
+      if ((Byte *)Ppmd8_GetPtr(p, successor) >= p->UnitsStart && order < p->MaxOrder)
+        SetSuccessor(s, RemoveBinContexts(p, CTX(successor), order + 1));
+      else
+        SetSuccessor(s, 0);
+    }
+    while (--s >= STATS(ctx));
+  }
+  
+  return REF(ctx);
+}
+
+#endif
+
+
+
+static UInt32 GetUsedMemory(const CPpmd8 *p)
+{
+  UInt32 v = 0;
+  unsigned i;
+  for (i = 0; i < PPMD_NUM_INDEXES; i++)
+    v += p->Stamps[i] * I2U(i);
+  return p->Size - (UInt32)(p->HiUnit - p->LoUnit) - (UInt32)(p->UnitsStart - p->Text) - U2B(v);
+}
+
+#ifdef PPMD8_FREEZE_SUPPORT
+  #define RESTORE_MODEL(c1, fSuccessor) RestoreModel(p, c1, fSuccessor)
+#else
+  #define RESTORE_MODEL(c1, fSuccessor) RestoreModel(p, c1)
+#endif
+
+
+static void RestoreModel(CPpmd8 *p, CTX_PTR ctxError
+    #ifdef PPMD8_FREEZE_SUPPORT
+    , CTX_PTR fSuccessor
+    #endif
+    )
+{
+  CTX_PTR c;
+  CPpmd_State *s;
+  RESET_TEXT(0);
+
+  // we go here in cases of error of allocation for context (c1)
+  // Order(MinContext) < Order(ctxError) <= Order(MaxContext)
+  
+  // We remove last symbol from each of contexts [p->MaxContext ... ctxError) contexts
+  // So we rollback all created (symbols) before error.
+  for (c = p->MaxContext; c != ctxError; c = SUFFIX(c))
+    if (--(c->NumStats) == 0)
+    {
+      s = STATS(c);
+      c->Flags = (Byte)((c->Flags & FLAG_PREV_HIGH) + PPMD8_HiBitsFlag_3(s->Symbol));
+      // *ONE_STATE(c) = *s;
+      c->Union2.State2.Symbol = s->Symbol;
+      c->Union2.State2.Freq = (Byte)(((unsigned)s->Freq + 11) >> 3);
+      c->Union4.State4.Successor_0 = s->Successor_0;
+      c->Union4.State4.Successor_1 = s->Successor_1;
+
+      SpecialFreeUnit(p, s);
+    }
+    else
+    {
+      /* Refresh() can increase Escape_Freq on value of Freq of last symbol, that was added before error.
+         so the largest possible increase for Escape_Freq is (8) from value before ModelUpoadet() */
+      Refresh(p, c, ((unsigned)c->NumStats + 3) >> 1, 0);
+    }
+ 
+  // increase Escape Freq for context [ctxError ... p->MinContext)
+  for (; c != p->MinContext; c = SUFFIX(c))
+    if (c->NumStats == 0)
+    {
+      // ONE_STATE(c)
+      c->Union2.State2.Freq = (Byte)(((unsigned)c->Union2.State2.Freq + 1) >> 1);
+    }
+    else if ((c->Union2.SummFreq = (UInt16)(c->Union2.SummFreq + 4)) > 128 + 4 * c->NumStats)
+      Refresh(p, c, ((unsigned)c->NumStats + 2) >> 1, 1);
+
+  #ifdef PPMD8_FREEZE_SUPPORT
+  if (p->RestoreMethod > PPMD8_RESTORE_METHOD_FREEZE)
+  {
+    p->MaxContext = fSuccessor;
+    p->GlueCount += !(p->Stamps[1] & 1); // why?
+  }
+  else if (p->RestoreMethod == PPMD8_RESTORE_METHOD_FREEZE)
+  {
+    while (p->MaxContext->Suffix)
+      p->MaxContext = SUFFIX(p->MaxContext);
+    RemoveBinContexts(p, p->MaxContext, 0);
+    // we change the current mode to (PPMD8_RESTORE_METHOD_FREEZE + 1)
+    p->RestoreMethod = PPMD8_RESTORE_METHOD_FREEZE + 1;
+    p->GlueCount = 0;
+    p->OrderFall = p->MaxOrder;
+  }
+  else
+  #endif
+  if (p->RestoreMethod == PPMD8_RESTORE_METHOD_RESTART || GetUsedMemory(p) < (p->Size >> 1))
+    RestartModel(p);
+  else
+  {
+    while (p->MaxContext->Suffix)
+      p->MaxContext = SUFFIX(p->MaxContext);
+    do
+    {
+      CutOff(p, p->MaxContext, 0);
+      ExpandTextArea(p);
+    }
+    while (GetUsedMemory(p) > 3 * (p->Size >> 2));
+    p->GlueCount = 0;
+    p->OrderFall = p->MaxOrder;
+  }
+  p->MinContext = p->MaxContext;
+}
+
+
+
+MY_NO_INLINE
+static CTX_PTR CreateSuccessors(CPpmd8 *p, BoolInt skip, CPpmd_State *s1, CTX_PTR c)
+{
+
+  CPpmd_Byte_Ref upBranch = (CPpmd_Byte_Ref)SUCCESSOR(p->FoundState);
+  Byte newSym, newFreq, flags;
+  unsigned numPs = 0;
+  CPpmd_State *ps[PPMD8_MAX_ORDER + 1]; /* fixed over Shkarin's code. Maybe it could work without + 1 too. */
+  
+  if (!skip)
+    ps[numPs++] = p->FoundState;
+  
+  while (c->Suffix)
+  {
+    CPpmd_Void_Ref successor;
+    CPpmd_State *s;
+    c = SUFFIX(c);
+    
+    if (s1) { s = s1; s1 = NULL; }
+    else if (c->NumStats != 0)
+    {
+      Byte sym = p->FoundState->Symbol;
+      for (s = STATS(c); s->Symbol != sym; s++);
+      if (s->Freq < MAX_FREQ - 9) { s->Freq++; c->Union2.SummFreq++; }
+    }
+    else
+    {
+      s = ONE_STATE(c);
+      s->Freq = (Byte)(s->Freq + (!SUFFIX(c)->NumStats & (s->Freq < 24)));
+    }
+    successor = SUCCESSOR(s);
+    if (successor != upBranch)
+    {
+
+      c = CTX(successor);
+      if (numPs == 0)
+      {
+        
+       
+        return c;
+      }
+      break;
+    }
+    ps[numPs++] = s;
+  }
+  
+  
+  
+  
+  
+  newSym = *(const Byte *)Ppmd8_GetPtr(p, upBranch);
+  upBranch++;
+  flags = (Byte)(PPMD8_HiBitsFlag_4(p->FoundState->Symbol) + PPMD8_HiBitsFlag_3(newSym));
+  
+  if (c->NumStats == 0)
+    newFreq = c->Union2.State2.Freq;
+  else
+  {
+    UInt32 cf, s0;
+    CPpmd_State *s;
+    for (s = STATS(c); s->Symbol != newSym; s++);
+    cf = (UInt32)s->Freq - 1;
+    s0 = (UInt32)c->Union2.SummFreq - c->NumStats - cf;
+    /*
+    
+
+      max(newFreq)= (s->Freq - 1), when (s0 == 1)
+
+
+    */
+    newFreq = (Byte)(1 + ((2 * cf <= s0) ? (5 * cf > s0) : ((cf + 2 * s0 - 3) / s0)));
+  }
+
+
+
+  do
+  {
+    CTX_PTR c1;
+    /* = AllocContext(p); */
+    if (p->HiUnit != p->LoUnit)
+      c1 = (CTX_PTR)(void *)(p->HiUnit -= UNIT_SIZE);
+    else if (p->FreeList[0] != 0)
+      c1 = (CTX_PTR)RemoveNode(p, 0);
+    else
+    {
+      c1 = (CTX_PTR)AllocUnitsRare(p, 0);
+      if (!c1)
+        return NULL;
+    }
+    c1->Flags = flags;
+    c1->NumStats = 0;
+    c1->Union2.State2.Symbol = newSym;
+    c1->Union2.State2.Freq = newFreq;
+    SetSuccessor(ONE_STATE(c1), upBranch);
+    c1->Suffix = REF(c);
+    SetSuccessor(ps[--numPs], REF(c1));
+    c = c1;
+  }
+  while (numPs != 0);
+  
+  return c;
+}
+
+
+static CTX_PTR ReduceOrder(CPpmd8 *p, CPpmd_State *s1, CTX_PTR c)
+{
+  CPpmd_State *s = NULL;
+  CTX_PTR c1 = c;
+  CPpmd_Void_Ref upBranch = REF(p->Text);
+  
+  #ifdef PPMD8_FREEZE_SUPPORT
+  /* The BUG in Shkarin's code was fixed: ps could overflow in CUT_OFF mode. */
+  CPpmd_State *ps[PPMD8_MAX_ORDER + 1];
+  unsigned numPs = 0;
+  ps[numPs++] = p->FoundState;
+  #endif
+
+  SetSuccessor(p->FoundState, upBranch);
+  p->OrderFall++;
+
+  for (;;)
+  {
+    if (s1)
+    {
+      c = SUFFIX(c);
+      s = s1;
+      s1 = NULL;
+    }
+    else
+    {
+      if (!c->Suffix)
+      {
+        #ifdef PPMD8_FREEZE_SUPPORT
+        if (p->RestoreMethod > PPMD8_RESTORE_METHOD_FREEZE)
+        {
+          do { SetSuccessor(ps[--numPs], REF(c)); } while (numPs);
+          RESET_TEXT(1);
+          p->OrderFall = 1;
+        }
+        #endif
+        return c;
+      }
+      c = SUFFIX(c);
+      if (c->NumStats)
+      {
+        if ((s = STATS(c))->Symbol != p->FoundState->Symbol)
+          do { s++; } while (s->Symbol != p->FoundState->Symbol);
+        if (s->Freq < MAX_FREQ - 9)
+        {
+          s->Freq = (Byte)(s->Freq + 2);
+          c->Union2.SummFreq = (UInt16)(c->Union2.SummFreq + 2);
+        }
+      }
+      else
+      {
+        s = ONE_STATE(c);
+        s->Freq = (Byte)(s->Freq + (s->Freq < 32));
+      }
+    }
+    if (SUCCESSOR(s))
+      break;
+    #ifdef PPMD8_FREEZE_SUPPORT
+    ps[numPs++] = s;
+    #endif
+    SetSuccessor(s, upBranch);
+    p->OrderFall++;
+  }
+  
+  #ifdef PPMD8_FREEZE_SUPPORT
+  if (p->RestoreMethod > PPMD8_RESTORE_METHOD_FREEZE)
+  {
+    c = CTX(SUCCESSOR(s));
+    do { SetSuccessor(ps[--numPs], REF(c)); } while (numPs);
+    RESET_TEXT(1);
+    p->OrderFall = 1;
+    return c;
+  }
+  else
+  #endif
+  if (SUCCESSOR(s) <= upBranch)
+  {
+    CTX_PTR successor;
+    CPpmd_State *s2 = p->FoundState;
+    p->FoundState = s;
+
+    successor = CreateSuccessors(p, False, NULL, c);
+    if (!successor)
+      SetSuccessor(s, 0);
+    else
+      SetSuccessor(s, REF(successor));
+    p->FoundState = s2;
+  }
+  
+  {
+    CPpmd_Void_Ref successor = SUCCESSOR(s);
+    if (p->OrderFall == 1 && c1 == p->MaxContext)
+    {
+      SetSuccessor(p->FoundState, successor);
+      p->Text--;
+    }
+    if (successor == 0)
+      return NULL;
+    return CTX(successor);
+  }
+}
+
+
+
+void Ppmd8_UpdateModel(CPpmd8 *p);
+MY_NO_INLINE
+void Ppmd8_UpdateModel(CPpmd8 *p)
+{
+  CPpmd_Void_Ref maxSuccessor, minSuccessor = SUCCESSOR(p->FoundState);
+  CTX_PTR c;
+  unsigned s0, ns, fFreq = p->FoundState->Freq;
+  Byte flag, fSymbol = p->FoundState->Symbol;
+  {
+  CPpmd_State *s = NULL;
+  if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0)
+  {
+    /* Update Freqs in Suffix Context */
+
+    c = SUFFIX(p->MinContext);
+    
+    if (c->NumStats == 0)
+    {
+      s = ONE_STATE(c);
+      if (s->Freq < 32)
+        s->Freq++;
+    }
+    else
+    {
+      Byte sym = p->FoundState->Symbol;
+      s = STATS(c);
+
+      if (s->Symbol != sym)
+      {
+        do
+        {
+        
+          s++;
+        }
+        while (s->Symbol != sym);
+        
+        if (s[0].Freq >= s[-1].Freq)
+        {
+          SwapStates(&s[0], &s[-1]);
+          s--;
+        }
+      }
+      
+      if (s->Freq < MAX_FREQ - 9)
+      {
+        s->Freq = (Byte)(s->Freq + 2);
+        c->Union2.SummFreq = (UInt16)(c->Union2.SummFreq + 2);
+      }
+    }
+  }
+  
+  c = p->MaxContext;
+  if (p->OrderFall == 0 && minSuccessor)
+  {
+    CTX_PTR cs = CreateSuccessors(p, True, s, p->MinContext);
+    if (!cs)
+    {
+      SetSuccessor(p->FoundState, 0);
+      RESTORE_MODEL(c, CTX(minSuccessor));
+      return;
+    }
+    SetSuccessor(p->FoundState, REF(cs));
+    p->MinContext = p->MaxContext = cs;
+    return;
+  }
+  
+
+
+
+  {
+    Byte *text = p->Text;
+    *text++ = p->FoundState->Symbol;
+    p->Text = text;
+    if (text >= p->UnitsStart)
+    {
+      RESTORE_MODEL(c, CTX(minSuccessor)); /* check it */
+      return;
+    }
+    maxSuccessor = REF(text);
+  }
+
+  if (!minSuccessor)
+  {
+    CTX_PTR cs = ReduceOrder(p, s, p->MinContext);
+    if (!cs)
+    {
+      RESTORE_MODEL(c, NULL);
+      return;
+    }
+    minSuccessor = REF(cs);
+  }
+  else if ((Byte *)Ppmd8_GetPtr(p, minSuccessor) < p->UnitsStart)
+  {
+    CTX_PTR cs = CreateSuccessors(p, False, s, p->MinContext);
+    if (!cs)
+    {
+      RESTORE_MODEL(c, NULL);
+      return;
+    }
+    minSuccessor = REF(cs);
+  }
+  
+  if (--p->OrderFall == 0)
+  {
+    maxSuccessor = minSuccessor;
+    p->Text -= (p->MaxContext != p->MinContext);
+  }
+  #ifdef PPMD8_FREEZE_SUPPORT
+  else if (p->RestoreMethod > PPMD8_RESTORE_METHOD_FREEZE)
+  {
+    maxSuccessor = minSuccessor;
+    RESET_TEXT(0);
+    p->OrderFall = 0;
+  }
+  #endif
+  }
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+  
+
+  
+  
+  flag = (Byte)(PPMD8_HiBitsFlag_3(fSymbol));
+  s0 = p->MinContext->Union2.SummFreq - (ns = p->MinContext->NumStats) - fFreq;
+  
+  for (; c != p->MinContext; c = SUFFIX(c))
+  {
+    unsigned ns1;
+    UInt32 sum;
+    
+    if ((ns1 = c->NumStats) != 0)
+    {
+      if ((ns1 & 1) != 0)
+      {
+        /* Expand for one UNIT */
+        unsigned oldNU = (ns1 + 1) >> 1;
+        unsigned i = U2I(oldNU);
+        if (i != U2I((size_t)oldNU + 1))
+        {
+          void *ptr = AllocUnits(p, i + 1);
+          void *oldPtr;
+          if (!ptr)
+          {
+            RESTORE_MODEL(c, CTX(minSuccessor));
+            return;
+          }
+          oldPtr = STATS(c);
+          MyMem12Cpy(ptr, oldPtr, oldNU);
+          InsertNode(p, oldPtr, i);
+          c->Union4.Stats = STATS_REF(ptr);
+        }
+      }
+      sum = c->Union2.SummFreq;
+      /* max increase of Escape_Freq is 1 here.
+         an average increase is 1/3 per symbol */
+      sum += (3 * ns1 + 1 < ns);
+      /* original PPMdH uses 16-bit variable for (sum) here.
+         But (sum < ???). Do we need to truncate (sum) to 16-bit */
+      // sum = (UInt16)sum;
+    }
+    else
+    {
+      
+      CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0);
+      if (!s)
+      {
+        RESTORE_MODEL(c, CTX(minSuccessor));
+        return;
+      }
+      {
+        unsigned freq = c->Union2.State2.Freq;
+        // s = *ONE_STATE(c);
+        s->Symbol = c->Union2.State2.Symbol;
+        s->Successor_0 = c->Union4.State4.Successor_0;
+        s->Successor_1 = c->Union4.State4.Successor_1;
+        // SetSuccessor(s, c->Union4.Stats);  // call it only for debug purposes to check the order of
+                                              // (Successor_0 and Successor_1) in LE/BE.
+        c->Union4.Stats = REF(s);
+        if (freq < MAX_FREQ / 4 - 1)
+          freq <<= 1;
+        else
+          freq = MAX_FREQ - 4;
+
+        s->Freq = (Byte)freq;
+
+        sum = freq + p->InitEsc + (ns > 2);   // Ppmd8 (> 2)
+      }
+    }
+
+    {
+      CPpmd_State *s = STATS(c) + ns1 + 1;
+      UInt32 cf = 2 * (sum + 6) * (UInt32)fFreq;
+      UInt32 sf = (UInt32)s0 + sum;
+      s->Symbol = fSymbol;
+      c->NumStats = (Byte)(ns1 + 1);
+      SetSuccessor(s, maxSuccessor);
+      c->Flags |= flag;
+      if (cf < 6 * sf)
+      {
+        cf = (unsigned)1 + (cf > sf) + (cf >= 4 * sf);
+        sum += 4;
+        /* It can add (1, 2, 3) to Escape_Freq */
+      }
+      else
+      {
+        cf = (unsigned)4 + (cf > 9 * sf) + (cf > 12 * sf) + (cf > 15 * sf);
+        sum += cf;
+      }
+
+      c->Union2.SummFreq = (UInt16)sum;
+      s->Freq = (Byte)cf;
+    }
+
+  }
+  p->MaxContext = p->MinContext = CTX(minSuccessor);
+}
+  
+
+
+MY_NO_INLINE
+static void Rescale(CPpmd8 *p)
+{
+  unsigned i, adder, sumFreq, escFreq;
+  CPpmd_State *stats = STATS(p->MinContext);
+  CPpmd_State *s = p->FoundState;
+
+  /* Sort the list by Freq */
+  if (s != stats)
+  {
+    CPpmd_State tmp = *s;
+    do
+      s[0] = s[-1];
+    while (--s != stats);
+    *s = tmp;
+  }
+
+  sumFreq = s->Freq;
+  escFreq = p->MinContext->Union2.SummFreq - sumFreq;
+
+
+  
+  
+  
+  
+  adder = (p->OrderFall != 0);
+  
+  #ifdef PPMD8_FREEZE_SUPPORT
+  adder |= (p->RestoreMethod > PPMD8_RESTORE_METHOD_FREEZE);
+  #endif
+  
+  sumFreq = (sumFreq + 4 + adder) >> 1;
+  i = p->MinContext->NumStats;
+  s->Freq = (Byte)sumFreq;
+  
+  do
+  {
+    unsigned freq = (++s)->Freq;
+    escFreq -= freq;
+    freq = (freq + adder) >> 1;
+    sumFreq += freq;
+    s->Freq = (Byte)freq;
+    if (freq > s[-1].Freq)
+    {
+      CPpmd_State tmp = *s;
+      CPpmd_State *s1 = s;
+      do
+      {
+        s1[0] = s1[-1];
+      }
+      while (--s1 != stats && freq > s1[-1].Freq);
+      *s1 = tmp;
+    }
+  }
+  while (--i);
+  
+  if (s->Freq == 0)
+  {
+    /* Remove all items with Freq == 0 */
+    CPpmd8_Context *mc;
+    unsigned numStats, numStatsNew, n0, n1;
+    
+    i = 0; do { i++; } while ((--s)->Freq == 0);
+    
+    
+
+    
+    escFreq += i;
+    mc = p->MinContext;
+    numStats = mc->NumStats;
+    numStatsNew = numStats - i;
+    mc->NumStats = (Byte)(numStatsNew);
+    n0 = (numStats + 2) >> 1;
+    
+    if (numStatsNew == 0)
+    {
+    
+      unsigned freq = (2 * (unsigned)stats->Freq + escFreq - 1) / escFreq;
+      if (freq > MAX_FREQ / 3)
+        freq = MAX_FREQ / 3;
+      mc->Flags = (Byte)((mc->Flags & FLAG_PREV_HIGH) + PPMD8_HiBitsFlag_3(stats->Symbol));
+      
+      
+      
+      
+      
+      s = ONE_STATE(mc);
+      *s = *stats;
+      s->Freq = (Byte)freq;
+      p->FoundState = s;
+      InsertNode(p, stats, U2I(n0));
+      return;
+    }
+
+    n1 = (numStatsNew + 2) >> 1;
+    if (n0 != n1)
+      mc->Union4.Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1));
+    {
+      // here we are for max order only. So Ppmd8_MakeEscFreq() doesn't use mc->Flags
+      // but we still need current (Flags & FLAG_PREV_HIGH), if we will convert context to 1-symbol context later.
+      /*
+      unsigned flags = HiBits_Prepare((s = STATS(mc))->Symbol);
+      i = mc->NumStats;
+      do { flags |= HiBits_Prepare((++s)->Symbol); } while (--i);
+      mc->Flags = (Byte)((mc->Flags & ~FLAG_SYM_HIGH) + HiBits_Convert_3(flags));
+      */
+    }
+  }
+
+
+
+  
+
+
+  {
+    CPpmd8_Context *mc = p->MinContext;
+    mc->Union2.SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1));
+    mc->Flags |= FLAG_RESCALED;
+    p->FoundState = STATS(mc);
+  }
+}
+
+
+CPpmd_See *Ppmd8_MakeEscFreq(CPpmd8 *p, unsigned numMasked1, UInt32 *escFreq)
+{
+  CPpmd_See *see;
+  const CPpmd8_Context *mc = p->MinContext;
+  unsigned numStats = mc->NumStats;
+  if (numStats != 0xFF)
+  {
+    // (3 <= numStats + 2 <= 256)   (3 <= NS2Indx[3] and NS2Indx[256] === 26)
+    see = p->See[(size_t)(unsigned)p->NS2Indx[(size_t)numStats + 2] - 3]
+        + (mc->Union2.SummFreq > 11 * (numStats + 1))
+        + 2 * (unsigned)(2 * numStats < ((unsigned)SUFFIX(mc)->NumStats + numMasked1))
+        + mc->Flags;
+
+    {
+      // if (see->Summ) field is larger than 16-bit, we need only low 16 bits of Summ
+      unsigned summ = (UInt16)see->Summ; // & 0xFFFF
+      unsigned r = (summ >> see->Shift);
+      see->Summ = (UInt16)(summ - r);
+      *escFreq = r + (r == 0);
+    }
+  }
+  else
+  {
+    see = &p->DummySee;
+    *escFreq = 1;
+  }
+  return see;
+}
+
+ 
+static void NextContext(CPpmd8 *p)
+{
+  CTX_PTR c = CTX(SUCCESSOR(p->FoundState));
+  if (p->OrderFall == 0 && (const Byte *)c >= p->UnitsStart)
+    p->MaxContext = p->MinContext = c;
+  else
+    Ppmd8_UpdateModel(p);
+}
+ 
+
+void Ppmd8_Update1(CPpmd8 *p)
+{
+  CPpmd_State *s = p->FoundState;
+  unsigned freq = s->Freq;
+  freq += 4;
+  p->MinContext->Union2.SummFreq = (UInt16)(p->MinContext->Union2.SummFreq + 4);
+  s->Freq = (Byte)freq;
+  if (freq > s[-1].Freq)
+  {
+    SwapStates(s, &s[-1]);
+    p->FoundState = --s;
+    if (freq > MAX_FREQ)
+      Rescale(p);
+  }
+  NextContext(p);
+}
+
+
+void Ppmd8_Update1_0(CPpmd8 *p)
+{
+  CPpmd_State *s = p->FoundState;
+  CPpmd8_Context *mc = p->MinContext;
+  unsigned freq = s->Freq;
+  unsigned summFreq = mc->Union2.SummFreq;
+  p->PrevSuccess = (2 * freq >= summFreq); // Ppmd8 (>=)
+  p->RunLength += (int)p->PrevSuccess;
+  mc->Union2.SummFreq = (UInt16)(summFreq + 4);
+  freq += 4;
+  s->Freq = (Byte)freq;
+  if (freq > MAX_FREQ)
+    Rescale(p);
+  NextContext(p);
+}
+
+
+/*
+void Ppmd8_UpdateBin(CPpmd8 *p)
+{
+  unsigned freq = p->FoundState->Freq;
+  p->FoundState->Freq = (Byte)(freq + (freq < 196)); // Ppmd8 (196)
+  p->PrevSuccess = 1;
+  p->RunLength++;
+  NextContext(p);
+}
+*/
+
+void Ppmd8_Update2(CPpmd8 *p)
+{
+  CPpmd_State *s = p->FoundState;
+  unsigned freq = s->Freq;
+  freq += 4;
+  p->RunLength = p->InitRL;
+  p->MinContext->Union2.SummFreq = (UInt16)(p->MinContext->Union2.SummFreq + 4);
+  s->Freq = (Byte)freq;
+  if (freq > MAX_FREQ)
+    Rescale(p);
+  Ppmd8_UpdateModel(p);
+}
+
+/* H->I changes:
+  NS2Indx
+  GlueCount, and Glue method
+  BinSum
+  See / EscFreq
+  CreateSuccessors updates more suffix contexts
+  Ppmd8_UpdateModel consts.
+  PrevSuccess Update
+
+Flags:
+  (1 << 2) - the Context was Rescaled
+  (1 << 3) - there is symbol in Stats with (sym >= 0x40) in
+  (1 << 4) - main symbol of context is (sym >= 0x40)
+*/