I do not agree. The MVCLE instruction always sets the condition code, to 0|1|2|3. Examination of how the original MVC works in a loop will help to explicate the design of MVCLE. The MVC-in-a-loop idiom required/requires an additional, cleanup EXecuted MVC. MVCLE does not.
Moreover, I am not a great admirer of adolescent cynicism, simplistic dietrologia, and the like. In my now long experience with System/360 and zArchitecture I have encountered machine instructions 1) that could have done more, 2) that I should have implemented differently, and 3) that were implemented incorrectly, this last just once; but I have never encountered one that had been implemented on the cheap, one way instead of the other because the one was cheaper/easier than the other. The older generation of IBM designers, whom I knew better, just did not think that way; and I have seen no even slight indication that the current one does so. John Gilmore, Ashland, MA 01721 - USA
