Re: Redefining a DS

Simon Coulter wrote:

These are both things we did as common practice for efficiently clearing
and/or initializing areas of memory in Assembler.

But in Assembly Language the Assembler only does what you tell it to do. If you didn't make use of a temporary then you changed the value you are about to copy thus each element (byte) gets the same value. With HLLs a reasonable compiler (i.e., not C and its ilk) will generally do what is reasonably expected by the programmer.

It turns out (or appears)
that the MI is pulling some tricks under the covers.

Probably not the MI but rather the compiler.

This is probably the source of the confusion. RPG doesn't expect you to be using assembly language tricks to initialize a buffer, because you can do it in other ways. Although I don't see an EASY way of initializing a buffer to a computed value. You can do it with a little trickery (basing an array, for example), but nothing quite as simple as the overlapping move.

Joe