It is easy to misunderstand what being a "modal instruction" means. The instructions mentioned are not modal; they do not behave differently depending on AMODE. Thus, as Tom points out, they are not AMODE sensitive and will operate identically in any AMODE. What does depend on AMODE, however, is address resolution. In 31-bit mode, only 31 bits of a base or index register are used to create an address used to reference storage. In 64-bit mode, all 64 bits are used. Hope that helps.
-----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Tom Marchant Sent: Tuesday, May 05, 2015 9:47 AM To: [email protected] Subject: Re: LNKEDT 64-bit mode assembler in AMODE 31 On Tue, 5 May 2015 09:36:13 -0400, Brite wrote: >I compared to the performance of same programs before they were >converted to 64-bit. How do those 64-bit instructions (e.g. LGR, STMG, >LMG) work in 31-bit AMODE? This is the first I have to deal with 64-bit >mode. They work just fine. Those instructions are not AMODE sensitive. -- Tom Marchant The contents of this e-mail are intended for the named addressee only. It contains information that may be confidential. Unless you are the named addressee or an authorized designee, you may not copy or use it, or disclose it to anyone else. If you received it in error please notify us immediately and then destroy it
