ADR 0046: Separate execution-mask and predicate domains (superseded)

The historical B.Z/B.NZ consumer clause is also superseded by ADR 0067. PTO has no accepted conditional-branch consumer for the machine execution mask.

• Decision date: 2026-07-31

Superseding decision

The earlier decision modeled a separate execution mask for machine-parallel and machine-sequential block bodies. PTO no longer accepts those block-start families and reserves their complete encoding space. PTO therefore has no machine-body execution-mask state, entry behavior, trap payload, or branch selection rule.

P0 through P7 remain distinct 32-bit predicate registers. P0 reads all ones and ignores writes; P1 through P7 reset to zero and are trap-preserved. No accepted PTO instruction produces or consumes them. B.Z and B.NZ consume the bundle commit argument established by SETC.*.

This file records the superseded decision only. The current executable contract is defined by the ASL architecture and scalar BRU units.