AE2 VM: Legacy

AE2 VM: Legacy is an unofficial fork of Tao's AE2-VM for modern Minecraft (NeoForge 1.21.1), ported to Minecraft 1.12.2 with Cleanroom or Forge + MixinBooter, running on AE2 Unofficial Extended Life. All credit for the original architecture goes to Tao; see Credits below.

What it does

AE2 VM replaces Applied Energistics 2's recursive crafting-tree traversal with a pre-compiled pattern bytecode + stack-based virtual machine + JIT bundle cache. Crafting requests that stall the vanilla planner for minutes — deeply nested, exponentially recursive patterns — are planned in milliseconds (upstream benchmark: ~90 s → ~38 ms, ~2,400×). Stack overflows are impossible by construction: there is no recursion anywhere in the pipeline.

Why it's fast AND correct

• O(patterns + edges) demand propagation over the pattern graph instead of node-by-node expansion; JIT bundles capture each pattern once and replay it scaled in O(1)
• BigInteger arithmetic everywhere — 10^9-scale chains, amount-1 boundaries, no overflow
• Stock-aware planning — network inventory is consumed first, shortfalls are crafted; catalyst feedback loops, durability tools and conversion rings all get exact semantics
• Amplifying crafting rings — circular recipes that net-grow per round (a self-feeding loop whose outputs outweigh its inputs) are detected, solved algebraically to the material-minimal counts and folded into a single plan; byproduct intermediates, external inputs, byproduct-rooted orders and coupled ring chains are all covered, and the startup working capital is reported exactly
• Multi-pattern assignment solver — when one output has several patterns, mixed splits (5 crafts = 4×A + 1×B) are solved algebraically and encoded as a virtual pattern; this closes upstream's only remaining false-positive (carried since v1.9.6)
• Guards everywhere — dead-cycle pre-pruning, stale-pattern-proof JIT cache keys, plan memoization re-verified against live stock, and a material-closure adoption gate for the ring solver: a solver can only ever be declined, never make a plan worse
• Compatibility — AE2FC fluid patterns, AE2CT display trees, third-party scaled-pattern wrappers, with automatic fallback to the vanilla planning tree if the VM cannot handle a request

Performance

All 39 reference-suite scenarios × 3 stock modes are SUPPORTED with zero flakiness, plus 37/37 boundary checks; the deep-chain micro-benchmark plans a Fibonacci-32 chain at 10^9 scale in ~0.6 ms (hot median). Fresh benchmarks are published to the wiki automatically on every release.

Getting started

1. Install Minecraft 1.12.2 with the Cleanroom loader (recommended), or Forge + MixinBooter
2. Install AE2 Unofficial Extended Life (this mod is compatible with every 1.12.2 build of AE2UEL)
3. Put this mod's jar into mods/ — done.

The VM takes over crafting calculations automatically; no setup, no config needed. Encode AE2 patterns as usual, request a craft from the terminal, and the VM accelerates the calculation transparently. To return to vanilla planning, set proxyEnabled=false in config/ae2_vm_112-common.toml.

Supported recipes: crafting patterns (molecular assemblers) and processing patterns of any depth, including the mega-recipes common in AE2 addon packs. Calculation runs on a background thread — no server main-thread lag.

On the Forge route: the mod uses no Cleanroom-specific APIs and ships Java 8 bytecode, so it is expected to work out of the box. This route is not covered by our automated tests — feedback is welcome.

Requirements

Links

• Source code & issue tracker: https://github.com/shinyashen/AE2-VM-1.12
• Full documentation (bilingual wiki): https://github.com/shinyashen/AE2-VM-1.12/wiki
• Changelog: see the Files tab of each release

Credits & license

This is a fork of AE2-VM by Tao — the crafting-VM architecture, instruction semantics and test baselines all originate there (LGPL-3.0). Thanks also to NNYYOONNIIOO & contributors (AE2-Quick-Calculation, integration shell reference), Circulate233 (RandomComplement, build system reference), moakiee (TB-ThirdParty, test-only reference planner), AlgorithmX2 et al. for Applied Energistics 2, and the AE2UEL team for the 1.12 platform.

This port is released under LGPL-3.0, same as upstream.