MVCX sounds a bit like MVCOS with R00=0. The PoOP says MVCOS may be significantly slower than MVC, but I would be interested to see a comparison between it and an executed MVC i.e. for use in short(ish) variable length moves.
Robert Ngan CSC Financial Services Group From: "Peurifoy, Richard L" <r-peuri...@neo.tamu.edu> To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Date: 2013/04/17 10:49 Subject: Re: Millicode Instructions Sent by: IBM Mainframe Assembler List <ASSEMBLER-LIST@LISTSERV.UGA.EDU> > Some millicode instructions will outperform their PoOp-code > counterparts > because millicode has access to hardware features not available to > ordinary code. For example, MVCL(E) has the ability to move data > under > certain conditions without loading it into cache. (You can't do that > with looping MVC.) Millicode routines also have access to the MVCX > instruction which performs a variable-length MVC -- something > ordinary > programs cannot do without using the EXecute instruction. MVCX sounds like it would be usefull for non-millicode, any idea why it was not externalized? Is there a coresponding CLCX? -- Richard
