**     different sized allocations. Memory cells provide growable
  **     allocations.
  **
  **   * When using ENABLE_MEMORY_MANAGEMENT, memory cell buffers can
  **     be freed lazily via the sqlite3_release_memory() API. This
  **     minimizes the number of malloc calls made by the system.
  **
  ** The memory cell for cursor 0 is aMem[0]. The rest are allocated from
  ** Memory cells for cursors are allocated at the top of the address
  ** the top of the register space.  Cursor 1 is at Mem[p->nMem-1].
  ** space. Memory cell (p->nMem) corresponds to cursor 0. Space for
  ** cursor 1 is managed by memory cell (p->nMem-1), etc.
  ** Cursor 2 is at Mem[p->nMem-2]. And so forth.
  */
  Mem *pMem = &p->aMem[p->nMem-iCur];
  Mem *pMem = iCur>0 ? &p->aMem[p->nMem-iCur] : p->aMem;

  int nByte;
  VdbeCursor *pCx = 0;
  nByte = 
      ROUND8(sizeof(VdbeCursor)) + 2*sizeof(u32)*nField + 
      (eCurType==CURTYPE_BTREE?sqlite3BtreeCursorSize():0);

  assert( iCur<p->nCursor );
  assert( iCur>=0 && iCur<p->nCursor );
  if( p->apCsr[iCur] ){
    sqlite3VdbeFreeCursor(p, p->apCsr[iCur]);
    p->apCsr[iCur] = 0;
  }
  if( SQLITE_OK==sqlite3VdbeMemClearAndResize(pMem, nByte) ){
    p->apCsr[iCur] = pCx = (VdbeCursor*)pMem->z;
    memset(pCx, 0, sizeof(VdbeCursor));

  sqlite3VdbeMemSetNull(pOut);
  pOut->flags = MEM_Int;
  return pOut;
}
static Mem *out2Prerelease(Vdbe *p, VdbeOp *pOp){
  Mem *pOut;
  assert( pOp->p2>0 );
  assert( pOp->p2<=(p->nMem-p->nCursor) );
  assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
  pOut = &p->aMem[pOp->p2];
  memAboutToChange(p, pOut);
  if( VdbeMemDynamic(pOut) ){
    return out2PrereleaseWithClear(pOut);
  }else{
    pOut->flags = MEM_Int;
    return pOut;

#endif

    /* Sanity checking on other operands */
#ifdef SQLITE_DEBUG
    assert( pOp->opflags==sqlite3OpcodeProperty[pOp->opcode] );
    if( (pOp->opflags & OPFLG_IN1)!=0 ){
      assert( pOp->p1>0 );
      assert( pOp->p1<=(p->nMem-p->nCursor) );
      assert( pOp->p1<=(p->nMem+1 - p->nCursor) );
      assert( memIsValid(&aMem[pOp->p1]) );
      assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p1]) );
      REGISTER_TRACE(pOp->p1, &aMem[pOp->p1]);
    }
    if( (pOp->opflags & OPFLG_IN2)!=0 ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=(p->nMem-p->nCursor) );
      assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
      assert( memIsValid(&aMem[pOp->p2]) );
      assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p2]) );
      REGISTER_TRACE(pOp->p2, &aMem[pOp->p2]);
    }
    if( (pOp->opflags & OPFLG_IN3)!=0 ){
      assert( pOp->p3>0 );
      assert( pOp->p3<=(p->nMem-p->nCursor) );
      assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
      assert( memIsValid(&aMem[pOp->p3]) );
      assert( sqlite3VdbeCheckMemInvariants(&aMem[pOp->p3]) );
      REGISTER_TRACE(pOp->p3, &aMem[pOp->p3]);
    }
    if( (pOp->opflags & OPFLG_OUT2)!=0 ){
      assert( pOp->p2>0 );
      assert( pOp->p2<=(p->nMem-p->nCursor) );
      assert( pOp->p2<=(p->nMem+1 - p->nCursor) );
      memAboutToChange(p, &aMem[pOp->p2]);
    }
    if( (pOp->opflags & OPFLG_OUT3)!=0 ){
      assert( pOp->p3>0 );
      assert( pOp->p3<=(p->nMem-p->nCursor) );
      assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
      memAboutToChange(p, &aMem[pOp->p3]);
    }
#endif
#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
    pOrigOp = pOp;
#endif
  

/* Opcode:  Gosub P1 P2 * * *
**
** Write the current address onto register P1
** and then jump to address P2.
*/
case OP_Gosub: {            /* jump */
  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
  pIn1 = &aMem[pOp->p1];
  assert( VdbeMemDynamic(pIn1)==0 );
  memAboutToChange(p, pIn1);
  pIn1->flags = MEM_Int;
  pIn1->u.i = (int)(pOp-aOp);
  REGISTER_TRACE(pOp->p1, pIn1);

** If P2!=0 then the coroutine implementation immediately follows
** this opcode.  So jump over the coroutine implementation to
** address P2.
**
** See also: EndCoroutine
*/
case OP_InitCoroutine: {     /* jump */
  assert( pOp->p1>0 &&  pOp->p1<=(p->nMem-p->nCursor) );
  assert( pOp->p1>0 &&  pOp->p1<=(p->nMem+1 - p->nCursor) );
  assert( pOp->p2>=0 && pOp->p2<p->nOp );
  assert( pOp->p3>=0 && pOp->p3<p->nOp );
  pOut = &aMem[pOp->p1];
  assert( !VdbeMemDynamic(pOut) );
  pOut->u.i = pOp->p3 - 1;
  pOut->flags = MEM_Int;
  if( pOp->p2 ) goto jump_to_p2;

  pOut->z = pOp->p4.z;
  pOut->n = pOp->p1;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
  if( pOp->p5 ){
    assert( pOp->p3>0 );
    assert( pOp->p3<=(p->nMem-p->nCursor) );
    assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
    pIn3 = &aMem[pOp->p3];
    assert( pIn3->flags & MEM_Int );
    if( pIn3->u.i ) pOut->flags = MEM_Blob|MEM_Static|MEM_Term;
  }
#endif
  break;
}

** OP_Ne or OP_Eq.
*/
case OP_Null: {           /* out2 */
  int cnt;
  u16 nullFlag;
  pOut = out2Prerelease(p, pOp);
  cnt = pOp->p3-pOp->p2;
  assert( pOp->p3<=(p->nMem-p->nCursor) );
  assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
  pOut->flags = nullFlag = pOp->p1 ? (MEM_Null|MEM_Cleared) : MEM_Null;
  while( cnt>0 ){
    pOut++;
    memAboutToChange(p, pOut);
    sqlite3VdbeMemSetNull(pOut);
    pOut->flags = nullFlag;
    cnt--;
  }
  break;
}

/* Opcode: SoftNull P1 * * * *
** Synopsis:  r[P1]=NULL
**
** Set register P1 to have the value NULL as seen by the OP_MakeRecord
** instruction, but do not free any string or blob memory associated with
** the register, so that if the value was a string or blob that was
** previously copied using OP_SCopy, the copies will continue to be valid.
*/
case OP_SoftNull: {
  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
  pOut = &aMem[pOp->p1];
  pOut->flags = (pOut->flags|MEM_Null)&~MEM_Undefined;
  break;
}

/* Opcode: Blob P1 P2 * P4 *
** Synopsis: r[P2]=P4 (len=P1)

  p2 = pOp->p2;
  assert( n>0 && p1>0 && p2>0 );
  assert( p1+n<=p2 || p2+n<=p1 );

  pIn1 = &aMem[p1];
  pOut = &aMem[p2];
  do{
    assert( pOut<=&aMem[(p->nMem-p->nCursor)] );
    assert( pIn1<=&aMem[(p->nMem-p->nCursor)] );
    assert( pOut<=&aMem[(p->nMem+1 - p->nCursor)] );
    assert( pIn1<=&aMem[(p->nMem+1 - p->nCursor)] );
    assert( memIsValid(pIn1) );
    memAboutToChange(p, pOut);
    sqlite3VdbeMemMove(pOut, pIn1);
#ifdef SQLITE_DEBUG
    if( pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrom<pOut ){
      pOut->pScopyFrom += pOp->p2 - p1;
    }

** the result row.
*/
case OP_ResultRow: {
  Mem *pMem;
  int i;
  assert( p->nResColumn==pOp->p2 );
  assert( pOp->p1>0 );
  assert( pOp->p1+pOp->p2<=(p->nMem-p->nCursor)+1 );
  assert( pOp->p1+pOp->p2<=(p->nMem+1 - p->nCursor)+1 );

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  /* Run the progress counter just before returning.
  */
  if( db->xProgress!=0
   && nVmStep>=nProgressLimit
   && db->xProgress(db->pProgressArg)!=0

*/
case OP_Function0: {
  int n;
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCDEF );
  n = pOp->p5;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem-p->nCursor)+1) );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
  if( pCtx==0 ) goto no_mem;
  pCtx->pOut = 0;
  pCtx->pFunc = pOp->p4.pFunc;
  pCtx->iOp = (int)(pOp - aOp);
  pCtx->pVdbe = p;

  assert( pKeyInfo!=0 );
  p1 = pOp->p1;
  p2 = pOp->p2;
#if SQLITE_DEBUG
  if( aPermute ){
    int k, mx = 0;
    for(k=0; k<n; k++) if( aPermute[k]>mx ) mx = aPermute[k];
    assert( p1>0 && p1+mx<=(p->nMem-p->nCursor)+1 );
    assert( p2>0 && p2+mx<=(p->nMem-p->nCursor)+1 );
    assert( p1>0 && p1+mx<=(p->nMem+1 - p->nCursor)+1 );
    assert( p2>0 && p2+mx<=(p->nMem+1 - p->nCursor)+1 );
  }else{
    assert( p1>0 && p1+n<=(p->nMem-p->nCursor)+1 );
    assert( p2>0 && p2+n<=(p->nMem-p->nCursor)+1 );
    assert( p1>0 && p1+n<=(p->nMem+1 - p->nCursor)+1 );
    assert( p2>0 && p2+n<=(p->nMem+1 - p->nCursor)+1 );
  }
#endif /* SQLITE_DEBUG */
  for(i=0; i<n; i++){
    idx = aPermute ? aPermute[i] : i;
    assert( memIsValid(&aMem[p1+idx]) );
    assert( memIsValid(&aMem[p2+idx]) );
    REGISTER_TRACE(p1+idx, &aMem[p1+idx]);

  pC = p->apCsr[pOp->p1];
  p2 = pOp->p2;

  /* If the cursor cache is stale, bring it up-to-date */
  rc = sqlite3VdbeCursorMoveto(&pC, &p2);

  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pC!=0 );
  assert( p2<pC->nField );
  aOffset = pC->aOffset;
  assert( pC->eCurType!=CURTYPE_VTAB );

  char cAff;               /* A single character of affinity */

  zAffinity = pOp->p4.z;
  assert( zAffinity!=0 );
  assert( zAffinity[pOp->p2]==0 );
  pIn1 = &aMem[pOp->p1];
  while( (cAff = *(zAffinity++))!=0 ){
    assert( pIn1 <= &p->aMem[(p->nMem-p->nCursor)] );
    assert( pIn1 <= &p->aMem[(p->nMem+1 - p->nCursor)] );
    assert( memIsValid(pIn1) );
    applyAffinity(pIn1, cAff, encoding);
    pIn1++;
  }
  break;
}

  ** of the record to data0.
  */
  nData = 0;         /* Number of bytes of data space */
  nHdr = 0;          /* Number of bytes of header space */
  nZero = 0;         /* Number of zero bytes at the end of the record */
  nField = pOp->p1;
  zAffinity = pOp->p4.z;
  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=(p->nMem-p->nCursor)+1 );
  assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=(p->nMem+1 - p->nCursor)+1 );
  pData0 = &aMem[nField];
  nField = pOp->p2;
  pLast = &pData0[nField-1];
  file_format = p->minWriteFileFormat;

  /* Identify the output register */
  assert( pOp->p3<pOp->p1 || pOp->p3>=pOp->p1+pOp->p2 );

    /* EVIDENCE-OF: R-64536-51728 The values for each column in the record
    ** immediately follow the header. */
    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
  }while( (++pRec)<=pLast );
  assert( i==nHdr );
  assert( j==nByte );

  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  pOut->n = (int)nByte;
  pOut->flags = MEM_Blob;
  if( nZero ){
    pOut->u.nZero = nZero;
    pOut->flags |= MEM_Zero;
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */

      p->minWriteFileFormat = pDb->pSchema->file_format;
    }
  }else{
    wrFlag = 0;
  }
  if( pOp->p5 & OPFLAG_P2ISREG ){
    assert( p2>0 );
    assert( p2<=(p->nMem-p->nCursor) );
    assert( p2<=(p->nMem+1 - p->nCursor) );
    pIn2 = &aMem[p2];
    assert( memIsValid(pIn2) );
    assert( (pIn2->flags & MEM_Int)!=0 );
    sqlite3VdbeMemIntegerify(pIn2);
    p2 = (int)pIn2->u.i;
    /* The p2 value always comes from a prior OP_CreateTable opcode and
    ** that opcode will always set the p2 value to 2 or more or else fail.

      if( p->pFrame ){
        for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
        /* Assert that P3 is a valid memory cell. */
        assert( pOp->p3<=pFrame->nMem );
        pMem = &pFrame->aMem[pOp->p3];
      }else{
        /* Assert that P3 is a valid memory cell. */
        assert( pOp->p3<=(p->nMem-p->nCursor) );
        assert( pOp->p3<=(p->nMem+1 - p->nCursor) );
        pMem = &aMem[pOp->p3];
        memAboutToChange(p, pMem);
      }
      assert( memIsValid(pMem) );

      REGISTER_TRACE(pOp->p3, pMem);
      sqlite3VdbeMemIntegerify(pMem);

case OP_IdxDelete: {
  VdbeCursor *pC;
  BtCursor *pCrsr;
  int res;
  UnpackedRecord r;

  assert( pOp->p3>0 );
  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem-p->nCursor)+1 );
  assert( pOp->p2>0 && pOp->p2+pOp->p3<=(p->nMem+1 - p->nCursor)+1 );
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
  assert( pC->eCurType==CURTYPE_BTREE );
  pCrsr = pC->uc.pCursor;
  assert( pCrsr!=0 );
  assert( pOp->p5==0 );

  Mem *pnErr;     /* Register keeping track of errors remaining */

  assert( p->bIsReader );
  nRoot = pOp->p2;
  aRoot = pOp->p4.ai;
  assert( nRoot>0 );
  assert( aRoot[nRoot]==0 );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  pnErr = &aMem[pOp->p3];
  assert( (pnErr->flags & MEM_Int)!=0 );
  assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &aMem[pOp->p1];
  assert( pOp->p5<db->nDb );
  assert( DbMaskTest(p->btreeMask, pOp->p5) );
  z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,

  if( (pRt->flags&MEM_Frame)==0 ){
    /* SubProgram.nMem is set to the number of memory cells used by the 
    ** program stored in SubProgram.aOp. As well as these, one memory
    ** cell is required for each cursor used by the program. Set local
    ** variable nMem (and later, VdbeFrame.nChildMem) to this value.
    */
    nMem = pProgram->nMem + pProgram->nCsr;
    assert( nMem>0 );
    if( pProgram->nCsr==0 ) nMem++;
    nByte = ROUND8(sizeof(VdbeFrame))
              + nMem * sizeof(Mem)
              + pProgram->nCsr * sizeof(VdbeCursor *)
              + pProgram->nOnce * sizeof(u8);
    pFrame = sqlite3DbMallocZero(db, nByte);
    if( !pFrame ){
      goto no_mem;

    pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];
    for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){
      pMem->flags = MEM_Undefined;
      pMem->db = db;
    }
  }else{
    pFrame = pRt->u.pFrame;
    assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem );
    assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem 
        || (pProgram->nCsr==0 && pProgram->nMem+1==pFrame->nChildMem) );
    assert( pProgram->nCsr==pFrame->nChildCsr );
    assert( (int)(pOp - aOp)==pFrame->pc );
  }

  p->nFrame++;
  pFrame->pParent = p->pFrame;
  pFrame->lastRowid = lastRowid;
  pFrame->nChange = p->nChange;
  pFrame->nDbChange = p->db->nChange;
  assert( pFrame->pAuxData==0 );
  pFrame->pAuxData = p->pAuxData;
  p->pAuxData = 0;
  p->nChange = 0;
  p->pFrame = pFrame;
  p->aMem = aMem = &VdbeFrameMem(pFrame)[-1];
  p->aMem = aMem = VdbeFrameMem(pFrame);
  p->nMem = pFrame->nChildMem;
  p->nCursor = (u16)pFrame->nChildCsr;
  p->apCsr = (VdbeCursor **)&aMem[p->nMem+1];
  p->apCsr = (VdbeCursor **)&aMem[p->nMem];
  p->aOp = aOp = pProgram->aOp;
  p->nOp = pProgram->nOp;
  p->aOnceFlag = (u8 *)&p->apCsr[p->nCursor];
  p->nOnceFlag = pProgram->nOnce;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  p->anExec = 0;
#endif

*/
case OP_AggStep0: {
  int n;
  sqlite3_context *pCtx;

  assert( pOp->p4type==P4_FUNCDEF );
  n = pOp->p5;
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem-p->nCursor)+1) );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  assert( n==0 || (pOp->p2>0 && pOp->p2+n<=(p->nMem+1 - p->nCursor)+1) );
  assert( pOp->p3<pOp->p2 || pOp->p3>=pOp->p2+n );
  pCtx = sqlite3DbMallocRawNN(db, sizeof(*pCtx) + (n-1)*sizeof(sqlite3_value*));
  if( pCtx==0 ) goto no_mem;
  pCtx->pMem = 0;
  pCtx->pFunc = pOp->p4.pFunc;
  pCtx->iOp = (int)(pOp - aOp);
  pCtx->pVdbe = p;

** argument is not used by this opcode.  It is only there to disambiguate
** functions that can take varying numbers of arguments.  The
** P4 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {
  Mem *pMem;
  assert( pOp->p1>0 && pOp->p1<=(p->nMem-p->nCursor) );
  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
  pMem = &aMem[pOp->p1];
  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
  if( rc ){
    sqlite3VdbeError(p, "%s", sqlite3_value_text(pMem));
    goto abort_due_to_error;
  }

  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  Mem *pDest;
  sqlite3_context sContext;

  VdbeCursor *pCur = p->apCsr[pOp->p1];
  assert( pCur->eCurType==CURTYPE_VTAB );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
  pDest = &aMem[pOp->p3];
  memAboutToChange(p, pDest);
  if( pCur->nullRow ){
    sqlite3VdbeMemSetNull(pDest);
    break;
  }
  pVtab = pCur->uc.pVCur->pVtab;

  */
  assert( p->nOp>0 );

  /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */
  p->magic = VDBE_MAGIC_RUN;

#ifdef SQLITE_DEBUG
  for(i=1; i<p->nMem; i++){
  for(i=0; i<p->nMem; i++){
    assert( p->aMem[i].db==p->db );
  }
#endif
  p->pc = -1;
  p->rc = SQLITE_OK;
  p->errorAction = OE_Abort;
  p->nChange = 0;

  nVar = pParse->nVar;
  nMem = pParse->nMem;
  nCursor = pParse->nTab;
  nArg = pParse->nMaxArg;
  nOnce = pParse->nOnce;
  if( nOnce==0 ) nOnce = 1; /* Ensure at least one byte in p->aOnceFlag[] */
  
  /* For each cursor required, also allocate a memory cell. Memory
  /* Each cursor uses a memory cell.  The first cursor (cursor 0) can
  ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
  ** the vdbe program. Instead they are used to allocate memory for
  ** use aMem[0] which is not otherwise used by the VDBE program.  Allocate
  ** VdbeCursor/BtCursor structures. The blob of memory associated with 
  ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1)
  ** stores the blob of memory associated with cursor 1, etc.
  **
  ** space at the end of aMem[] for cursors 1 and greater.
  ** See also: allocateCursor().
  */
  nMem += nCursor;
  if( nCursor==0 && nMem>0 ) nMem++;  /* Space for aMem[0] even if not used */

  /* Figure out how much reusable memory is available at the end of the
  ** opcode array.  This extra memory will be reallocated for other elements
  ** of the prepared statement.
  */
  n = ROUND8(sizeof(Op)*p->nOp);              /* Bytes of opcode memory used */
  x.pSpace = &((u8*)p->aOp)[n];               /* Unused opcode memory */

    }
  }
  p->nzVar = pParse->nzVar;
  p->azVar = pParse->azVar;
  pParse->nzVar =  0;
  pParse->azVar = 0;
  if( p->aMem ){
    p->aMem--;                      /* aMem[] goes from 1..nMem */
    p->nMem = nMem;                 /*       not from 0..nMem-1 */
    for(n=1; n<=nMem; n++){
    p->nMem = nMem;
    for(n=0; n<nMem; n++){
      p->aMem[n].flags = MEM_Undefined;
      p->aMem[n].db = db;
    }
  }
  p->explain = pParse->explain;
  sqlite3VdbeRewind(p);
}

    sqlite3VdbeFrameRestore(pFrame);
    p->pFrame = 0;
    p->nFrame = 0;
  }
  assert( p->nFrame==0 );
  closeCursorsInFrame(p);
  if( p->aMem ){
    releaseMemArray(&p->aMem[1], p->nMem);
    releaseMemArray(p->aMem, p->nMem);
  }
  while( p->pDelFrame ){
    VdbeFrame *pDel = p->pDelFrame;
    p->pDelFrame = pDel->pParent;
    sqlite3VdbeFrameDelete(pDel);
  }

#ifdef SQLITE_DEBUG
  /* Execute assert() statements to ensure that the Vdbe.apCsr[] and 
  ** Vdbe.aMem[] arrays have already been cleaned up.  */
  int i;
  if( p->apCsr ) for(i=0; i<p->nCursor; i++) assert( p->apCsr[i]==0 );
  if( p->aMem ){
    for(i=1; i<=p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
    for(i=0; i<p->nMem; i++) assert( p->aMem[i].flags==MEM_Undefined );
  }
#endif

  sqlite3DbFree(db, p->zErrMsg);
  p->zErrMsg = 0;
  p->pResultSet = 0;
}

**
** This is used for testing and debugging only - to make sure shallow
** copies are not misused.
*/
void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
  int i;
  Mem *pX;
  for(i=1, pX=&pVdbe->aMem[1]; i<=pVdbe->nMem; i++, pX++){
  for(i=0, pX=pVdbe->aMem; i<pVdbe->nMem; i++, pX++){
    if( pX->pScopyFrom==pMem ){
      pX->flags |= MEM_Undefined;
      pX->pScopyFrom = 0;
    }
  }
  pMem->pScopyFrom = 0;
}