D085 - Shader tables are data

Status: decided Date: 2026-09-26

The instruction encodings, operand numbering, operand layouts, mnemonics and buffer formats live in data files under crates/orbistoun-shader/data/. A row is measured from the reference assembler or transcribed from the published instruction set with a citation; a mnemonic exists only for an instruction a compiler emitted and the reference disassembler named. An instruction with no name reports its family and opcode.

Why: every row is a claim about hardware, and a wrong row silently mis-decodes rather than failing to compile. As data a correction is an edit, checkable against a real shader in seconds, and the transcription stays separate from the code. An invented name sends a reader to the wrong instruction; a missing one costs ten seconds.

Rejected:

• A match in Rust: a correction becomes a release.
• A full transcribed opcode table: hundreds of rows nobody can check.