DC A(0-foocsect) has a valid negative relocatable expression; I don't know whether those are still supported, and have never used one. I doubt that they're legal on a USING.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU> on behalf of Paul Gilmartin <00000014e0e4a59b-dmarc-requ...@listserv.uga.edu> Sent: Monday, November 11, 2019 2:35 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Questionable Instructions in Obtaining EAX documentation On 2019-11-11, at 09:08:39, Steve Smith wrote: > > I must agree that USING on numbers is a questionable feature; also operand > 1 doesn't have to be 0, anything up to 2gb should work. > What's "questionable"? Should the Assembler require a relocatable expression? Why? An old (BitSavers) Assembler manual said the allowed range was (1-2**24,2**24-1). HLASM says, "non-negative". I don't believe either restriction was ever enforced. What does "negative" mean for a relocatable expression? Does it depdend on the address at which the CSECT/DSECT gets loaded? > ... My guess is somebody in 1964 thought it was a good idea. > Prior to the advent of immediate instructions there was no better alternative. -- gil
