What is house keeping in assembler? And explain the
following code
HELLOTSO START 0
* PRINT NOGEN
BEGIN SAVE (14,12)
LR 12,15
USING TYPE,12
ST 13,SAVE+4
LA 11,SAVE
ST 11,8(13)
LR 13,11
Answer Posted / john
To elaborate a little the reason for all this
"housekeeping": The "save areas" as they are called that are
created by the SAVE macro contain the contents of the
registers when the routine is called. Save areas are
backward and forward linked (by the 4 instructions after the
USING) so that if the program fails you can find them in a
dump. The ending part of the program is missing as well,
but it returns the registers to their previous state before
returning to the calling program. It might look something like:
DROP 12
ALLDONE L 13,SAVE+4
RETURN (14,12),RC=0
| Is This Answer Correct ? | 8 Yes | 3 No |
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