Some of this discussion revolves around what the "base knowledge" is that
you expect/require that the code's readers have.
If "everyone" understands that "SR regx,regx" and "XR regx,regx" zero
regx then there is little to no benefit to having a macro that is "ZERO
regx".
Drawing the line in the right place is perhaps the tricky part. Especially
with all the "new" instructions that might be less well understood.
Consider
L regx,PSATOLD fetch the address of the current TCB
Even that comment is inadequate if your reader will not know what a TCB
is. I suspect that most would choose to assume that a reader of this could
would know what a TCB is and not spell out the acronym, let alone describe
it..
Peter Relson
z/OS Core Technology Design
