Hash matrix

A scenario is a deterministic function that writes bytes to a ScenarioContext; its SHA-256 goes in a manifest. Two platforms agree when their manifests are identical.

Adding a scenario

Create a file under tools/HashMatrix/Scenarios/<area>/ (the HashMatrix project and the smoke apps compile everything beneath it) with a module initializer:

namespace RecursiveAI.OneMath.HashMatrix;
 
internal static class MyScenarios
{
    [System.Runtime.CompilerServices.ModuleInitializer]
    internal static void Init() => Scenarios.Register("area/name", ctx => { ctx.Write(1.0); });
}

No shared file changes. Names are lower-case, slash separated and unique; the manifest orders them by ordinal comparison. Writers (Write(int|long|float|double|bytes)) are little-endian by bit pattern; every NaN is written as one canonical NaN because arithmetic NaN sign and payload are chosen by the CPU. ctx.Threads is the worker count a parallel scenario should use; the output must not depend on it (split by index, combine in index order). Use a seeded generator, never Random or time.

Running

HashMatrix [--threads N] [--filter PREFIX] [--out FILE] [--list] prints name sha256 per scenario and a final manifest sha256 over those lines. tools/hash-matrix.sh runs every column (see its header) and compares them.

Columns: x64 JIT; x64 JIT with DOTNET_EnableHWIntrinsic=0; with DOTNET_EnableAVX2=0; 1 thread and all cores; x64 NativeAOT (tests/AotSmoke); browser-wasm interpreted and AOT-compiled (tests/WasmSmoke, run under Node); osx-arm64.