PG_FREE_IF_COPY()

Given the following snippet:
HeapTupleHeader     tuple;Datum               temp;bool              isnull;tuple = PG_GETARG_HEAPTUPLEHEADER(0);temp
=GetAttributeByName(tuple, "data", &isnull); 


When using this for a btree operator functions, you need to
PG_FREE_IF_COPY(?,?);

Which of the above parameters need I free?

tuple, or temp,.... Or both?

... John