SQLite

      */
      if( pDef->funcFlags & SQLITE_FUNC_UNLIKELY ){
        assert( nFarg>=1 );
        sqlite3ExprCode(pParse, pFarg->a[0].pExpr, target);
        break;
      }

      for(i=0; i<nFarg; i++){
        if( i<32 && sqlite3ExprIsConstant(pFarg->a[i].pExpr) ){
          constMask |= (1<<i);
        }
        if( (pDef->funcFlags & SQLITE_FUNC_NEEDCOLL)!=0 && !pColl ){
          pColl = sqlite3ExprCollSeq(pParse, pFarg->a[i].pExpr);
        }
      }
      if( pFarg ){
        if( constMask ){
          r1 = pParse->nMem+1;
          pParse->nMem += nFarg;
        }else{
          r1 = sqlite3GetTempRange(pParse, nFarg);
        }

        /* For length() and typeof() functions with a column argument,
        ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
        ** or OPFLAG_TYPEOFARG respectively, to avoid unnecessary data
        ** loading.
        */
        if( (pDef->funcFlags & (SQLITE_FUNC_LENGTH|SQLITE_FUNC_TYPEOF))!=0 ){

            testcase( pDef->funcFlags & OPFLAG_LENGTHARG );
            pFarg->a[0].pExpr->op2 = 
                  pDef->funcFlags & (OPFLAG_LENGTHARG|OPFLAG_TYPEOFARG);
          }
        }

        sqlite3ExprCachePush(pParse);     /* Ticket 2ea2425d34be */
        sqlite3ExprCodeExprList(pParse, pFarg, r1, 
                                SQLITE_ECEL_DUP|SQLITE_ECEL_FACTOR);
        sqlite3ExprCachePop(pParse, 1);   /* Ticket 2ea2425d34be */
      }else{
        r1 = 0;
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      /* Possibly overload the function if the first argument is
      ** a virtual table column.

      */
      if( nFarg>=2 && (pExpr->flags & EP_InfixFunc) ){
        pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
      }else if( nFarg>0 ){
        pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
      }
#endif








      if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
        if( !pColl ) pColl = db->pDfltColl; 
        sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
      }
      sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
                        (char*)pDef, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)nFarg);
      if( nFarg && constMask==0 ){
        sqlite3ReleaseTempRange(pParse, r1, nFarg);
      }
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {

    }
#endif
  }
  sqlite3ReleaseTempReg(pParse, regFree1);
  sqlite3ReleaseTempReg(pParse, regFree2);
  return inReg;
}

/*
** Factor out the code of the given expression to initialization time.
*/
void sqlite3ExprCodeAtInit(Parse *pParse, Expr *pExpr, int regDest){
  ExprList *p;
  assert( pParse->cookieGoto>0 ); /* Only possible if cookie will be coded */
  p = pParse->pConstExpr;
  pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
  p = sqlite3ExprListAppend(pParse, p, pExpr);
  if( p ) p->a[p->nExpr-1].u.iConstExprReg = regDest;
  pParse->pConstExpr = p;
}

/*
** Generate code to evaluate an expression and store the results
** into a register.  Return the register number where the results
** are stored.
**
** If the register is a temporary register that can be deallocated,

    if( p ){
      for(i=0; i<p->nExpr; i++){
        if( sqlite3ExprCompare(p->a[i].pExpr, pExpr, -1)==0 ){
          return p->a[i].u.iConstExprReg;
        }
      }
    }


    r2 = ++pParse->nMem;

    sqlite3ExprCodeAtInit(pParse, pExpr, r2);
  }else{
    int r1 = sqlite3GetTempReg(pParse);
    r2 = sqlite3ExprCodeTarget(pParse, pExpr, r1);
    if( r2==r1 ){
      *pReg = r1;
    }else{
      sqlite3ReleaseTempReg(pParse, r1);

#endif /* SQLITE_DEBUG */

/*
** Generate code that pushes the value of every element of the given
** expression list into a sequence of registers beginning at target.
**
** Return the number of elements evaluated.
**
** The SQLITE_ECEL_DUP flag prevents the arguments from being
** filled using OP_SCopy.  OP_Copy must be used instead.
**
** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
** factored out into initialization code.
*/
int sqlite3ExprCodeExprList(
  Parse *pParse,     /* Parsing context */
  ExprList *pList,   /* The expression list to be coded */
  int target,        /* Where to write results */
  u8 flags           /* SQLITE_ECEL_* flags */
){
  struct ExprList_item *pItem;
  int i, n;
  u8 copyOp = (flags & SQLITE_ECEL_DUP) ? OP_Copy : OP_SCopy;
  assert( pList!=0 );
  assert( target>0 );
  assert( pParse->pVdbe!=0 );  /* Never gets this far otherwise */
  n = pList->nExpr;
  if( pParse->cookieGoto<=0 ) flags &= ~SQLITE_ECEL_FACTOR;
  for(pItem=pList->a, i=0; i<n; i++, pItem++){
    Expr *pExpr = pItem->pExpr;
    if( (flags & SQLITE_ECEL_FACTOR)!=0 && sqlite3ExprIsConstant(pExpr) ){
      sqlite3ExprCodeAtInit(pParse, pExpr, target+i);
    }else{
      int inReg = sqlite3ExprCodeTarget(pParse, pExpr, target+i);
      if( inReg!=target+i ){
        sqlite3VdbeAddOp2(pParse->pVdbe, copyOp, inReg, target+i);

      }
    }
  }
  return n;
}

/*
** Generate code for a BETWEEN operator.

      sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
    }
  }else if( eDest!=SRT_Exists ){
    /* If the destination is an EXISTS(...) expression, the actual
    ** values returned by the SELECT are not required.
    */
    sqlite3ExprCacheClear(pParse);
    sqlite3ExprCodeExprList(pParse, pEList, regResult,
                            (eDest==SRT_Output)?SQLITE_ECEL_DUP:0);
  }
  nColumn = nResultCol;

  /* If the DISTINCT keyword was present on the SELECT statement
  ** and this row has been seen before, then do not make this row
  ** part of the result.
  */

    int addrNext = 0;
    int regAgg;
    ExprList *pList = pF->pExpr->x.pList;
    assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
    if( pList ){
      nArg = pList->nExpr;
      regAgg = sqlite3GetTempRange(pParse, nArg);
      sqlite3ExprCodeExprList(pParse, pList, regAgg, SQLITE_ECEL_DUP);
    }else{
      nArg = 0;
      regAgg = 0;
    }
    if( pF->iDistinct>=0 ){
      addrNext = sqlite3VdbeMakeLabel(v);
      assert( nArg==1 );

void sqlite3ExprCacheStore(Parse*, int, int, int);
void sqlite3ExprCachePush(Parse*);
void sqlite3ExprCachePop(Parse*, int);
void sqlite3ExprCacheRemove(Parse*, int, int);
void sqlite3ExprCacheClear(Parse*);
void sqlite3ExprCacheAffinityChange(Parse*, int, int);
int sqlite3ExprCode(Parse*, Expr*, int);
void sqlite3ExprCodeAtInit(Parse*, Expr*, int);
int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
int sqlite3ExprCodeTarget(Parse*, Expr*, int);
int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
int sqlite3ExprCodeExprList(Parse*, ExprList*, int, u8);
#define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
#define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */
void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
Table *sqlite3FindTable(sqlite3*,const char*, const char*);
Table *sqlite3LocateTable(Parse*,int isView,const char*, const char*);
Table *sqlite3LocateTableItem(Parse*,int isView,struct SrcList_item *);
Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);