890   int regOld,                     /* Previous row data is stored here */  in sqlite3FkCheck()  argument
902   assert( (regOld==0)!=(regNew==0) );  in sqlite3FkCheck()
939       assert( isIgnoreErrors==0 || (regOld!=0 && regNew==0) );  in sqlite3FkCheck()
954           iReg = sqlite3TableColumnToStorage(pFKey->pFrom,iFromCol) + regOld+1;  in sqlite3FkCheck()
993     if( regOld!=0 ){  in sqlite3FkCheck()
997       fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, bIgnore);  in sqlite3FkCheck()
1028       assert( regOld==0 && regNew!=0 );  in sqlite3FkCheck()
1053       if( regOld!=0 ){  in sqlite3FkCheck()
1055         fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);  in sqlite3FkCheck()
1409   int regOld,                     /* Address of array containing old row */  in sqlite3FkActions()  argument
1423           sqlite3CodeRowTriggerDirect(pParse, pAct, pTab, regOld, OE_Abort, 0);  in sqlite3FkActions()