> -----Original Message----- > From: IBM Mainframe Assembler List > [mailto:[email protected]] On Behalf Of Tom Marchant > Sent: Thursday, December 30, 2010 10:31 AM > To: [email protected] > Subject: Re: A bug or a feature? > > On Thu, 30 Dec 2010 16:36:14 +0100, Martin wrote: > > >One should use the offset off of the only valid/declared > >base-register at that point which is 3 > > Why don't you think that register 15 is a valid base register > for a long-displacement instruction? When you code > USING BASE,3 > it is equivalent to > USING (BASE,BASE+4096),3 > > -- > Tom Marchant
I think this is a "surprise" factor in that the USING range __IMPLICITLY__ addresses memory __before__ the symbol listed in the USING when a long displacement instruction is used. As I said of myself in a previous message, I never realized that the displacement in the long displacment was actually SIGNED and so could addresses memory locations BEFORE the given label. I always thought that the USING was only good for range of [label+0 to label+4096 (or smaller if the second label is there). And the HLASM manual says this. But it is only true of 12 bit displacement instructions. HLASM puts a lower limit of label-534388 on the USING when used with a long displacement instruction. But where does it say that in the manual? I know - that was my lack of dilligence and making assumptions. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM
