ADR 0088: Numeric special values

Context

ADR 0050 closes canonical produced NaNs plus comparison and min/max NaN and signed-zero selection for a bounded named-hardware operation set. Published and implementation evidence still distinguish propagation, sentinel, payload, infinity, conversion, reduction, quantization, matrix, and flag/status cases without one complete cross-operation rule.

The proposal under review extends the bit-exact rule beyond the bounded ADR 0050 checkpoint to infinity arithmetic, broader NaN creation, conversions, reductions, quantization, matrix operations, and the complete flag/status contract.

Affected domains

• cube-matrix
• scalar-binary
• scalar-fp-convert
• scalar-fp-to-integer
• scalar-fused
• scalar-unary
• tile-binary
• tile-compare
• tile-convert
• tile-dequantize
• tile-expand
• tile-fused
• tile-order
• tile-partial
• tile-quantize
• tile-reduction
• tile-unary

Alternatives considered

• portable normative rules;
• named target-profile rules; and
• implementation-defined rules with explicit allowed sets.

Blockers

• Extend bit-exact NaN creation rules beyond comparison and min/max.
• Define infinity arithmetic and special results for conversions, reductions, quantization, and matrix operations.
• Complete signaling-NaN flag and status interactions for every affected family.

Acceptance obligations

• A bit-exact special-value table extending ADR 0050.
• Coverage of all sign and payload classes.
• Binary, unary, conversion, compare, reduction, quantization, and matrix vectors.

Decision

No additional special-value rule is accepted by this draft.