( L1 LBL! .. L1 @ RJMP, )
: LBL! ( l -- ) PC SWAP ! ;
( L1 FLBL, .. RJMPOP L1 FLBL! )
: FLBL, ( l -- ) LBL! 0 A,, ;
: FLBL! ( l opw -- )
    ( warning: l is a PC offset, not a mem addr! )
    SWAP @ 2 * ORG @ + PC 1- H@ ( opw addr tgt hbkp )
    ROT HERE ! ( opw tgt hbkp ) SWAP ROT EXECUTE H@ ! ( hbkp )
    HERE ! ;
: FRJMP! ( l -- ) ['] RJMP FLBL! ;
: FRCALL! ( l -- ) ['] RCALL FLBL! ;