To someone writing performance code, and why else would you be writing assembler, MVCL/CLCL/etc are terrible instructions performance-wise unless you are moving over 32K of data.
In answer to the original question, there is no space in the instruction to add the bits. Changing the system to accommodate a 8 byte instruction is a BIG jump. LAY has worked for me in the past, and usually I can bury it a few instructions back, but even if I have to put it right up against the MVC, it will beat the heck out of a MVCL. Christopher Y. Blaicher Senior Software Developer Austin Development Lab phone: 512.340.6154 mobile: 512.627.3803 fax: 512.340.6647 10431 Morado Circle Austin, TX 78759 -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Steve Comstock Sent: Friday, December 03, 2010 4:21 PM To: [email protected] Subject: Re: Long Displacements - What Good Are They? But functionally you have MVCL, MVCLE, CLCL and CLCLE. Admittedly these have reputations for runinng relatively slow, but they have no restrictions vis a vis displacements, so you could use these to remove displacement or USING range restrictions. -- Kind regards, -Steve Comstock The Trainer's Friend, Inc. 303-393-8716 http://www.trainersfriend.com * To get a good Return on your Investment, first make an investment! + Training your people is an excellent investment * Try our new tool for calculating your Return On Investment for training dollars at http://www.trainersfriend.com/ROI/roi.html
