On 28 June 2018 at 16:23, Phil Smith III <li...@akphs.com> wrote: ... > I like the idea of PROTECT/UNPROT instructions*. Seems like the cleanest way > to do it to me. ... > *I wasn't sure of the right term for "a thing that the assembler looks at but > doesn't actually generate code"; Google found me IBM pages that refer to > USING as an "instruction", so I would take PROTECT/UNPROT to be in the same > category. Happy to be corrected, as ever.
The HLASM Language Reference differentiates "Machine instruction statements" from "Assembler instruction statements". Roughly, the former generate machine code and the latter don't. The line is pretty clear, but there are one or two fuzzy areas. For example, CNOP is an Assembler instruction statement, but it can generate code. CCW/CCW1 are also Assembler instruction statements that generate code; albeit not zArch code. And of course PUNCH and REPRO can put code into the object stream, but no one would call them Machine instruction statements. Tony H.