Anybody is free to use any subset of supported instructions and
element widths/types. The Z names can be extended down to individual
instructions/width if necessary.

However, we have to guide the software ecosystem where to spend the
available finite effort. So we choose and name some common
combinations to inform software/tool providers what to support, and to
enable compliance testing of those combinations.

We can always add new Z names later for subsets that prove popular.
This can happen after the instruction spec itself is ratified, in a
much lighter-weight process.

Krste

On Sat, 22 Aug 2020 00:32:56 -0700, "Allen Baum" <allen.baum@...> said:

| Works for me.
| -Allen

| On Aug 21, 2020, at 11:41 PM, Andrew Waterman <andrew@...> wrote:

| It's OK for esoteric combinations to require long ISA strings, I think.

|