SQLite

      int iBreak = sqlite3VdbeMakeLabel(v);
      int regGosub = ++pParse->nMem;

      sqlite3WindowCodeStep(pParse, p, pWInfo, regGosub, addrGosub);

      sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);
      sqlite3VdbeResolveLabel(v, addrGosub);
      VdbeNoopComment((v, "inner-loop subroutine"));
      selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest, iCont, iBreak);
      sqlite3VdbeResolveLabel(v, iCont);
      sqlite3VdbeAddOp1(v, OP_Return, regGosub);
      VdbeComment((v, "end inner-loop subroutine"));
      sqlite3VdbeResolveLabel(v, iBreak);
    }else
#endif /* SQLITE_OMIT_WINDOWFUNC */

  u8 eStart;              /* UNBOUNDED, CURRENT, PRECEDING or FOLLOWING */
  u8 eEnd;                /* UNBOUNDED, CURRENT, PRECEDING or FOLLOWING */
  Expr *pStart;           /* Expression for "<expr> PRECEDING" */
  Expr *pEnd;             /* Expression for "<expr> FOLLOWING" */
  Window *pNextWin;       /* Next window function belonging to this SELECT */
  Expr *pFilter;          /* The FILTER expression */
  FuncDef *pFunc;         /* The function */
  int iEphCsr;            /* Partition buffer or Peer buffer */
  int regAccum;
  int regResult;
  int csrApp;             /* Function cursor (used by min/max) */
  int regApp;             /* Function register (also used by min/max) */
  int regPart;            /* First in a set of registers holding PARTITION BY
                          ** and ORDER BY values for the window */
  Expr *pOwner;           /* Expression object this window is attached to */

*/
static void row_numberStepFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
  i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  /* row_numberValueFunc() is always called first, so the aggregate context
  ** is guaranteed to already exist. */
  if( ALWAYS(p) ) (*p)++;
  UNUSED_PARAMETER(nArg);
  UNUSED_PARAMETER(apArg);
}
static void row_numberValueFunc(sqlite3_context *pCtx){
  i64 *p = (i64*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  sqlite3_result_int64(pCtx, (p ? *p : 0));
}

static void dense_rankStepFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  /* p is not NULL because dense_rankValueFunc() will have been called first */
  if( ALWAYS(p) ) p->nStep = 1;
  UNUSED_PARAMETER(nArg);
  UNUSED_PARAMETER(apArg);
}
static void dense_rankValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p ){

static void rankStepFunc(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  /* p is not NULL because rankValueFunc() will have been called first */
  if( ALWAYS(p) ){
    p->nStep++;
    if( p->nValue==0 ){
      p->nValue = p->nStep;
    }
  }
  UNUSED_PARAMETER(nArg);
  UNUSED_PARAMETER(apArg);

  int nArg,
  sqlite3_value **apArg
){
  struct CallCount *p;
  UNUSED_PARAMETER(nArg); assert( nArg==1 );

  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  /* p is not NULL because percent_rankValueFunc() will have been called */
  if( ALWAYS(p) ){
    if( p->nTotal==0 ){
      p->nTotal = sqlite3_value_int64(apArg[0]);
    }
    p->nStep++;
    if( p->nValue==0 ){
      p->nValue = p->nStep;
    }

  int nArg,
  sqlite3_value **apArg
){
  struct CallCount *p;
  assert( nArg==1 ); UNUSED_PARAMETER(nArg);

  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  /* p is not NULL because cume_distValueFunc() will have been called first */
  if( ALWAYS(p) ){
    if( p->nTotal==0 ){
      p->nTotal = sqlite3_value_int64(apArg[0]);
    }
    p->nStep++;
  }
}
static void cume_distValueFunc(sqlite3_context *pCtx){

  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **apArg
){
  struct NtileCtx *p;
  assert( nArg==2 ); UNUSED_PARAMETER(nArg);
  p = (struct NtileCtx*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  /* p is not NULL because ntimeValueFunc() will have been called first */
  if( ALWAYS(p) ){
    if( p->nTotal==0 ){
      p->nParam = sqlite3_value_int64(apArg[0]);
      p->nTotal = sqlite3_value_int64(apArg[1]);
      if( p->nParam<=0 ){
        sqlite3_result_error(
            pCtx, "argument of ntile must be a positive integer", -1
        );

  int reg = pParse->nMem+1;
  int regRecord = reg+nSub;
  int regRowid = regRecord+1;

  *pRegSize = regRowid;
  pParse->nMem += nSub + 2;

  /* Load the column values for the row returned by the sub-select
  ** into an array of registers starting at reg. */
  for(k=0; k<nSub; k++){
    sqlite3VdbeAddOp3(v, OP_Column, iSubCsr, k, reg+k);
  }
  sqlite3VdbeAddOp3(v, OP_MakeRecord, reg, nSub, regRecord);

  /* Check if this is the start of a new partition. If so, call the
  ** flush_partition sub-routine.  */

  if( pMWin->eEnd==TK_UNBOUNDED ){
    pOrderBy = 0;
  }

  pParse->nMem += nSub + 2;

  /* Load the individual column values of the row returned by
  ** the sub-select into an array of registers. */
  for(k=0; k<nSub; k++){
    sqlite3VdbeAddOp3(v, OP_Column, iSubCsr, k, reg+k);
  }

  /* Check if this is the start of a new partition or peer group. */
  if( pPart || pOrderBy ){
    int nPart = (pPart ? pPart->nExpr : 0);