Godot JIT

A JIT-like backend for the GS SafeGDScript compiler, executed by libtcc inside a GDExtension.

This is a glue project that re-uses work that already exists by me. The compiler is from Godot Sandbox, the JIT is my libtcc fork from libriscv and the backend is more or less the AOT backend from Godot Sandbox Plus. Highly experimental, though it does run all 118 godot demo projects for 5 seconds without errors.

UnsafeGDScript

The extension registers UnsafeGDScript as a Godot ScriptLanguage. Use .ugd (or .unsafegd) files, attach them to nodes in scenes, or construct instances through the script resource:

var counter = load("res://counter.ugd").new(10)
print(counter.increment())

For example, counter.ugd can contain ordinary GDScript:

extends RefCounted

var total: int

func _init(start: int = 0):
    total = start

func increment(amount: int = 1) -> int:
    total += amount
    return total

The language uses SafeGDScript's syntax, including await for signals, timers, and other coroutine calls:

func delayed_answer() -> int:
    await get_tree().create_timer(0.1).timeout
    return 42

Editor completion, documentation, and profiler integration = not yet.

Since nobody's paying for this, don't have any expectations. Thank.

Extra language syntax

Since this is based on the Godot Sandbox SGD compiler, there is the same support for nullable types, unions, structs, traits and compact if var.

I will avoid repeating myself so here's the blog post.

Godot JIT directly

var jit = GodotJIT.new()
assert(jit.compile_sgd("func answer(n: int) -> int:\n    return n * 2 + 2\n"))
assert(jit.execute_function("answer", [20]) == 42)

Performance

Godot 4.6.3-stable, AMD Ryzen 9 7950X, release build, 100 000 iterations.

math

Benchmark	GDScript	JIT	Speedup	insn/op GD	insn/op JIT
bench_primitives	0.0225 µs/op	0.0044 µs/op	5.17x	518	52
bench_engine	0.0398 µs/op	0.0274 µs/op	1.45x	766	233

loops and calls

Benchmark	GDScript	JIT	Speedup	insn/op GD	insn/op JIT
integer_loop	1713 µs	167 µs	10.26x	400	35
local_calls	21247 µs	2666 µs	7.97x	4353	474
gameplay_loop	3533 µs	791 µs	4.47x	737	133
float_loop	2081 µs	607 µs	3.43x	484	36
vector_loop	1098 µs	390 µs	2.82x	255	27
object_calls	8757 µs	5566 µs	1.57x	1800	1085
callable_calls	8339 µs	5753 µs	1.45x	1839	1207
dictionary_loop	12801 µs	9917 µs	1.29x	3004	2251
array_loop	6510 µs	6230 µs	1.04x	1557	1020
Geometric mean			2.81x

typical game-like code

Benchmark	GDScript	JIT	Speedup	insn/op GD	insn/op JIT
batch_floor	0.081 µs/op	0.007 µs/op	11.63x	1843	127
batch_think	0.341 µs/op	0.080 µs/op	4.26x	7158	1349
batch_nearest	0.252 µs/op	0.063 µs/op	3.97x	5215	1210
batch_normalize	0.075 µs/op	0.023 µs/op	3.28x	1624	140
batch_iterate	0.169 µs/op	0.057 µs/op	2.98x	3529	1072
think_5	0.372 µs/op	0.172 µs/op	2.16x	8059	3290
nearest_5	0.293 µs/op	0.147 µs/op	1.99x	6116	3101
distance_5	0.243 µs/op	0.139 µs/op	1.75x	5337	3004
iterate_5	0.200 µs/op	0.132 µs/op	1.51x	4318	2938
nearest_0	0.132 µs/op	0.096 µs/op	1.37x	2945	2131
call_floor	0.113 µs/op	0.094 µs/op	1.20x	2632	2065
minigame	2.015 µs/op	1.805 µs/op	1.12x	40800	35940
normalize	0.107 µs/op	0.098 µs/op	1.09x	2413	1971

The benchmark that is likely closest to average Godot game code is think_5, about 2x GDScript performance.

Installing the addon

Extract godot-jit.zip into your Godot 4.6+ project directory, so the extension is at addons/godot_jit/, then restart the editor.

Release archives include Android ARM64/x86-64 (API 24+), Linux ARM64/x86-64, macOS Apple Silicon/Intel, and Windows x86-64 binaries.

Building for Android

With Android NDK r24 installed:

export ANDROID_NDK_ROOT=/path/to/android-ndk-r24
bash scripts/ci/build_android.sh arm64
bash scripts/ci/build_android.sh x86_64

I don't know, if they're locking down Android it's dead to me.

Game studios

Game studios will want the Godot Sandbox Plus module. See: https://plus.libriscv.no/

License

Copyright (C) 2026 Alf-André Walla.

Godot JIT is licensed under the GNU Lesser General Public License version 3 (LGPL-3.0-only). See LICENSE, COPYING.LESSER, and COPYING. Third-party components retain their respective licenses.