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      break;
    }
  }
  zBuf[i]  = 0;
  return i>0 ? zBuf : 0;
}

/*
** Make sure there is space in the Vdbe structure to hold at least
** mxCursor cursors.  If there is not currently enough space, then
** allocate more.
**
** If a memory allocation error occurs, return 1.  Return 0 if
** everything works.
*/
static int expandCursorArraySize(Vdbe *p, int mxCursor){
  if( mxCursor>=p->nCursor ){
    Cursor *aCsr = sqliteRealloc( p->aCsr, (mxCursor+1)*sizeof(Cursor) );
    if( aCsr==0 ) return 1;
    p->aCsr = aCsr;
    memset(&p->aCsr[p->nCursor], 0, sizeof(Cursor)*(mxCursor+1-p->nCursor));
    p->nCursor = mxCursor+1;
  }
  return 0;
}

#ifdef VDBE_PROFILE
/*
** The following routine only works on pentium-class processors.
** It uses the RDTSC opcode to read cycle count value out of the
** processor and returns that value.  This can be used for high-res
** profiling.
*/
__inline__ unsigned long long int hwtime(void){
  unsigned long long int x;
  __asm__("rdtsc\n\t"
          "mov %%edx, %%ecx\n\t"
          :"=A" (x));
  return x;
}
#endif

/*
** The CHECK_FOR_INTERRUPT macro defined here looks to see if the
** sqlite_interrupt() routine has been called.  If it has been, then
** processing of the VDBE program is interrupted.
**
** This macro added to every instruction that does a jump in order to
** implement a loop.  This test used to be on every single instruction,
** but that meant we more testing that we needed.  By only testing the
** flag on jump instructions, we get a (small) speed improvement.
*/
#define CHECK_FOR_INTERRUPT \
   if( db->flags & SQLITE_Interrupt ) goto abort_due_to_interrupt;


/*
** Execute as much of a VDBE program as we can then return.
**
** sqliteVdbeMakeReady() must be called before this routine in order to
** close the program with a final OP_Halt and to set up the callbacks
** and the error message pointer.
**
** Whenever a row or result data is available, this routine will either
** invoke the result callback (if there is one) or return with
** SQLITE_ROW.
**
** If an attempt is made to open a locked database, then this routine
** will either invoke the busy callback (if there is one) or it will
** return SQLITE_BUSY.
**
** If an error occurs, an error message is written to memory obtained
** from sqliteMalloc() and p->zErrMsg is made to point to that memory.
** The error code is stored in p->rc and this routine returns SQLITE_ERROR.
**
** If the callback ever returns non-zero, then the program exits
** immediately.  There will be no error message but the p->rc field is
** set to SQLITE_ABORT and this routine will return SQLITE_ERROR.
**
** A memory allocation error causes p->rc to be set to SQLITE_NOMEM and this
** routine to return SQLITE_ERROR.
**
** Other fatal errors return SQLITE_ERROR.
**
** After this routine has finished, sqliteVdbeFinalize() should be
** used to clean up the mess that was left behind.
*/
int sqliteVdbeExec(
  Vdbe *p                    /* The VDBE */
){
  int pc;                    /* The program counter */
  Op *pOp;                   /* Current operation */
  int rc = SQLITE_OK;        /* Value to return */
  sqlite *db = p->db;        /* The database */
  Mem *pTos;                 /* Top entry in the operand stack */
  char zBuf[100];            /* Space to sprintf() an integer */
#ifdef VDBE_PROFILE
  unsigned long long start;  /* CPU clock count at start of opcode */
  int origPc;                /* Program counter at start of opcode */
#endif
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int nProgressOps = 0;      /* Opcodes executed since progress callback. */
#endif

  if( p->magic!=VDBE_MAGIC_RUN ) return SQLITE_MISUSE;
  assert( db->magic==SQLITE_MAGIC_BUSY );
  assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
  p->rc = SQLITE_OK;
  assert( p->explain==0 );
  if( sqlite_malloc_failed ) goto no_mem;
  pTos = p->pTos;
  if( p->popStack ){
    popStack(&pTos, p->popStack);
    p->popStack = 0;
  }
  CHECK_FOR_INTERRUPT;
  for(pc=p->pc; rc==SQLITE_OK; pc++){
    assert( pc>=0 && pc<p->nOp );
    assert( pTos<=&p->aStack[pc] );
#ifdef VDBE_PROFILE
    origPc = pc;