On 4/14/20 11:32 PM, Peter Coghlan wrote:
I wonder could this have been the COBOL compiler abusing MVCL instructions
in situations where they were not the appropriate instructions to use?
Perhaps instructions such as MVCL would be expected to be "hot spots" because
they can deliver a relatively large amount of work for a single instruction?
Or is it that implementations of this instruction were sometimes poorer than
they ought to be and they were really not delivering bang for buck?
I was told back in the 1980s that for performance reasons MUSIC moved 4096 bytes of data via a series of MVC commands in place of one MVCL.
--
Drew Derbyshire
"All right, Mr. DeMille, I'm ready for my close-up." -- "Sunset Blvd.,"
