Just a few more multiplication instructions, and we will move forward in the alphabet from “M”. MHY is a companion instruction to MFY. These two instructions share the same instruction format: RXY-a. Remember that “Y”-type instructions can reach farther from the base address, both forward and backward. You can find a writeup here.
Review an Instruction: MHY
Categories:
1 thought on “Review an Instruction: MHY”
Leave a ReplyCancel reply
Related Posts
z/OS Training at Marist College Enrolling Nowz/OS Training at Marist College Enrolling Now
Marist College through the Institute of Data Center Professionals (IDCP) offers a variety of mainframe-based courses and professional z/OS certificates ...
Review an Instruction: MFYReview an Instruction: MFY
It’s been a few weeks since I’ve posted. Life intervenes occasionally. This post is for a Multiply (Fullword) instruction which ...
MGRK LinkMGRK Link
All articles are on the main site, but here is a link to the latest one. ...

Hilarious!
The ‘Y’ indexing affords extended addressability whilst (potentially) overflowing base register addressing.
Note to self – write, exclusively, re-entrant code and mind the constants in the CSECT