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, "SELECT 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 */
    {
      /* Use the standard inner loop. */
      selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest,
          sqlite3WhereContinueLabel(pWInfo),

  };
  static int aOp[] = { OP_Ge, OP_Ge, OP_Gt };
  Vdbe *v = sqlite3GetVdbe(pParse);
  int regZero = sqlite3GetTempReg(pParse);
  assert( eCond==0 || eCond==1 || eCond==2 );
  sqlite3VdbeAddOp2(v, OP_Integer, 0, regZero);
  sqlite3VdbeAddOp2(v, OP_MustBeInt, reg, sqlite3VdbeCurrentAddr(v)+2);
  VdbeCoverageIf(v, eCond==0);
  VdbeCoverageIf(v, eCond==1);
  VdbeCoverageIf(v, eCond==2);
  sqlite3VdbeAddOp3(v, aOp[eCond], regZero, sqlite3VdbeCurrentAddr(v)+2, reg);
  VdbeCoverageIf(v, eCond==0);
  VdbeCoverageIf(v, eCond==1);
  VdbeCoverageIf(v, eCond==2);
  sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_ERROR, OE_Abort);
  sqlite3VdbeAppendP4(v, (void*)azErr[eCond], P4_STATIC);
  sqlite3ReleaseTempReg(pParse, regZero);
}

/*
** Return the number of arguments passed to the window-function associated

    addr = sqlite3VdbeAddOp3(v, OP_Compare, regNewPart, pMWin->regPart,nPart);
    sqlite3VdbeAppendP4(v, (void*)pKeyInfo, P4_KEYINFO);
    sqlite3VdbeAddOp3(v, OP_Jump, addr+2, addr+4, addr+2);
    VdbeCoverage(v);
    sqlite3VdbeAddOp3(v, OP_Copy, regNewPart, pMWin->regPart, nPart-1);
    sqlite3VdbeAddOp2(v, OP_Gosub, regFlushPart, lblFlushPart);
    VdbeComment((v, "call flush_partition"));
  }

  /* Buffer the current row in the ephemeral table. */
  sqlite3VdbeAddOp2(v, OP_NewRowid, pMWin->iEphCsr, regRowid);
  sqlite3VdbeAddOp3(v, OP_Insert, pMWin->iEphCsr, regRecord, regRowid);

  /* End of the input loop */
  sqlite3WhereEnd(pWInfo);

  /* Invoke "flush_partition" to deal with the final (or only) partition */
  sqlite3VdbeAddOp2(v, OP_Gosub, regFlushPart, lblFlushPart);
  VdbeComment((v, "call flush_partition"));
}

/*
** Invoke the sub-routine at regGosub (generated by code in select.c) to
** return the current row of Window.iEphCsr. If all window functions are
** aggregate window functions that use the standard API, a single
** OP_Gosub instruction is all that this routine generates. Extra VM code

  addrGoto = sqlite3VdbeAddOp0(v, OP_Goto);

  /* Start of "flush_partition" */
  sqlite3VdbeResolveLabel(v, lblFlushPart);
  sqlite3VdbeAddOp2(v, OP_Once, 0, sqlite3VdbeCurrentAddr(v)+3);
  VdbeCoverage(v);
  VdbeComment((v, "Flush_partition subroutine"));
  sqlite3VdbeAddOp2(v, OP_OpenDup, csrStart, pMWin->iEphCsr);
  sqlite3VdbeAddOp2(v, OP_OpenDup, csrEnd, pMWin->iEphCsr);

  /* If either regStart or regEnd are not non-negative integers, throw 
  ** an exception.  */
  if( pMWin->pStart ){
    sqlite3ExprCode(pParse, pMWin->pStart, regStart);

  }
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);

  /* flush_partition_done: */
  sqlite3VdbeResolveLabel(v, lblFlushDone);
  sqlite3VdbeAddOp1(v, OP_ResetSorter, pMWin->iEphCsr);
  sqlite3VdbeAddOp1(v, OP_Return, regFlushPart);
  VdbeComment((v, "end flush_partition subroutine"));

  /* Jump to here to skip over flush_partition */
  sqlite3VdbeJumpHere(v, addrGoto);
}

/*
** This function does the work of sqlite3WindowCodeStep() for cases that