Re: "The evils of MOVE" by (Barbara Morris?)

On 25-Mar-2014 12:28 -0700, Charles Wilt wrote:

I seem to recall seeing an article or post by Barbara that provided
considerable detail into the intricacies of MOVE and why IBM
depreciated <sic> it by not including it in free form.

Now that fixed-form can appear with little effort or the conspicuous /free and /end-free tags, any implication that the instructions were deprecated seems somewhat insincere.

In my mind, I'm calling it "The evils of MOVE"... shades of "The
evils of GOTO" :)

Does anybody else recall this and more importantly do you have a
link to it?

No, but IMO the documentation for the various MOVE* instructions do a fine job of revealing their evils; i.e. a slew of nuanced effects noted to be based on the numerous variations on source and target data types and different sizes. While completely acceptable to have such a highly overloaded capability, general usages may tend to suffer problems due to the modified effects when minor changes to the data type or the data size\length were made; i.e. the changes might be manifest as a compiler or run-time error, instead of just producing some different results, if the instruction is not overloaded to that degree. To be clear, I think the evils are more about code maintenance than new code; i.e. someone originally choosing to effect explicitly what the MOVE* instruction provides is likely to get exactly what they want.