ADR 0064: B.FPATR Complete-Bundle Matrix PostProcess

• Date: 2026-08-11
• Deciders: PTO ISA maintainers
• Issue: #64

Current release inventory is governed by ASL and generated projections; numeric inventories below are acceptance-time history, not the current active decoder set.

Decision

PTO ISA 0.58.0 accepts B.FPATR as the single complete-bundle matrix post-processing attribute command. It is latched once per CUBE Matrix bundle, cleared with the bundle descriptor, and included in trap save/recover state. Missing, duplicate, or non-Matrix use is rejected as Fault_BundleControl; decode-reserved field values and fixed-bit mismatches use Fault_IllegalInstruction; accepted encodings with incompatible fields, operand streams, parameters, aliases, or derived shapes use Fault_TileLegality before allocation or destination effects.

The command form is a 32-bit L32 encoding with mask 0x00007fff, match and canonical None word 0x00002023. Its closed PreQuantMode table, ReLU and GroupN fields, reduction enables, and fixed bits are owned by the normative ASL instruction unit. Matrix B.DATR rounding/saturation legality is resolved after the complete bundle is known; the None mode requires RMode=NONE and Sat=0. Fixed FP16, BF16, E4M3, and HiF8 modes require RMode=NONE, fixed shift modes additionally require Sat=0, and programmable integer modes retain the full existing selector and final clamp/wrap control.

The dynamic B.IOT schema packs mathematical Local sources first, followed by optional RowMaxIn, vector quantization, and vector PReLU parameters, with up to eight Local sources and three Local destinations ordered as D, RowMaxOut, and GroupMaxOut. B.IOR scalar parameters retain the dense ADR 0055/0058 order, with LReLU-only consuming RegSrc0. Output commits are one atomic group.

Consequences

At acceptance time, the 0.58.0 command projection was corrected to 100 command forms and 574 total scalar-plus-command forms. Existing twelve CUBE operation IDs, selectors, and mathematical operand aliases remained unchanged. The earlier open numeric variation point is closed by Decisions 174 through 181 in ADR 0085. Assigned post-processing modes now have bit-exact conversion, activation, FP19, exceptional-value, saturation/wrap, packing, auxiliary reduction, numeric-status, and atomic-publication rules. A nonzero assigned mode no longer permits an identity or implementation-selected result. Activation selects the negative-path multiplier before the single destination conversion, signed zero participates in affine offsets, and assigned S5, S9, S17, and shifted-S16 intermediates saturate before final destination encoding.

The normative owners are asl/block/attributes/B.FPATR.asl, the complete bundle state/schema/dispatch/lifecycle units, the trap context and reference profile owners, and the CUBE execution profile hook. Catalog, documentation, traceability, binary-closure, and checked AVS projections are generated from those owners.