IEFBR14 (was Re: IND$FILE)

Sean Conner spc at conman.org
Mon Nov 19 15:24:35 CST 2018


It was thus said that the Great jim stephens via cctalk once stated:
> 
> IFBR14 if you all are not familiar with MVS / MVT batch programming is a 
> program which immediately terminates w/o any return codes by doing an 
> assembly language return to the caller of the job step via the contents 
> of R14 of the processor, which is also the return address.

  I've always been amused by IEFBR14 ever since I heard about it.  I first
came across it by this quote:

	Every program has at least one bug and can be shortened by at least
	one instruction---from which, by induction, one can deduce that
	every program can be reduced to one instruction which doesn't work.

IEFBR14 was this program---one instruction long, and it contained a bug:

	http://en.wikipedia.org/wiki/IEFBR14

  -spc (The fix doubled the size of the program---such bloat!)


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