decimal Conformance

Contract Split

decimal is the IEEE 754 arithmetic and interchange surface. General Decimal Arithmetic sticky status and traps belong to decimal_gda; passing the GDA corpus does not by itself establish the IEEE claim.

Independent IEEE Corpus

The committed IEEE corpus covers decimal32/64/128 DPD and BID interchange, canonical and non-canonical encodings, special values, flags, total order, and core arithmetic. The DPD fixture exhaustively checks all 1,024 declets.

Oracle Layers

Mandatory operation vectors use exact integer/rational construction and the documented DPD/BID bridge. Elementary families use independent high-precision or interval oracles when available. Values or encoded bits and IEEE flags are recorded independently so a numerically plausible result cannot hide a flag error.

The committed elementary layer contains 2,784 certified rows. MPFR 4.2.2 produces directed 768-bit dyadic endpoints; exact integer conversion rounds both endpoints into decimal32/64/128 under every DecimalRoundingMode, and the generator rejects a row unless result and flags are unique. Native, Wasm, Wasm-GC, and JavaScript each pass 2,949/2,949 tests after these rows are materialized; the full gate is 15,735/15,735. RDFP and Arb remain optional secondary routes and are not counted when unavailable.

Targets

just gate decimal runs native, Wasm, Wasm-GC, and JavaScript. LLVM is excluded because the required local artifacts are not part of the repository. Target-specific coefficient dispatch must not change value, encoding, or flags.

Boundaries

The checked matrix is finite and does not claim every IEEE 754 operation, every payload propagation policy, or every possible decimal input. The supplementary dd*/dq* decTest rows are diagnostics, not an IEEE oracle.

Reproduction

just conformance smoke decimal
just gate decimal
just decimal-kernel-ci

See the decimal data guide for corpus provenance, vector families, and failure records.