.dmJIT

.dmJIT is a Rust-based JIT compiler using modified auxtools, dmasm and Inkwell LLVM wrapper for boosting Byond DM performance without any hassle (such as rewriting/refactoring your DM code).

Implementation status

Roadmap

• PoC ✔️
• Deoptimization ✔️
• Sleeping proc deoptimization
• Calls ✔️
• Virtual calls ✔️
• Type probing deoptimization
• Heterogenous instruction optimization
• JITed-to-JITed direct calls
• Tiering
• Branch / Call counting
• Sleeping proc support

Opcodes

OpCode	Status
GetVar	SetCache, Field, Src, Local, Arg
SetVar	SetCache, Field, Local, Arg
Add	Float
Sub	Float
Tg	Float
Tl	Float
Tge	Float
Tle	Float
AugAdd	Float
AugSub	Float
Teq	✔️
Ret	✔️
End	✔️
Test	✔️
Jz	✔️
JmpOr	✔️
JmpAnd	✔️
Jmp	✔️
PushInt	✔️
PushVal	✔️
GetFlag	✔️
Pop	✔️
IsNull	✔️
Not	✔️
Mul	Float
CallGlobal	No sleep deopt
Call	StaticProc, DynamicProc, No sleep deopt
CallStatement	StaticProc, DynamicProc, No sleep deopt
Abs	✔️
RoundN	✔️

Dependencies

These instructions were taken directly from tgstation's rust-g documentation.

The Rust compiler:

1. Install the Rust compiler's dependencies (primarily the system linker):

   • Ubuntu: sudo apt-get install gcc-multilib
   • Windows (MSVC): Build Tools for Visual Studio 2017
   • Windows (GNU): No action required

2. Use the Rust installer, or another Rust installation method, or run the following:

   curl https://sh.rustup.rs -sSfo rustup-init.sh
   chmod +x rustup-init.sh
   # Nightly toolchain is required
   ./rustup-init.sh

   Alternatively without saving

   # Nightly toolchain is required
   curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain nightly

3. Set the default compiler to 32-bit:

   # Clone the `dm-jitaux` repository to a directory of your choice
   git clone https://github.com/ss220-space/dm-jitaux.git
   # in the `dm-jitaux` directory...
   cd dm-jitaux
   # Linux
   rustup target add i686-unknown-linux-gnu
   # Windows
   rustup target add i686-pc-windows-msvc
   
   # Clone the `auxtools` repository to a parent directory of dm-jitaux
   cd ..
   git clone https://github.com/ss220-space/auxtools.git --branch dm-jitaux
   # in the `auxtools` directory...
   cd auxtools
   # Linux
   rustup target add i686-unknown-linux-gnu
   # Windows
   rustup target add i686-pc-windows-msvc

System libraries:

• Ubuntu and Debian users run:

  sudo dpkg --add-architecture i386
  sudo apt-get update
  sudo apt-get install zlib1g-dev:i386 libssl-dev:i386 pkg-config:i386
  sudo apt-get install gcc-multilib g++-multilib

• Other Linux distributions install the appropriate 32-bit development and 32-bit runtime packages.

Building

LLVM

Windows

CMake required, can be downloaded from cmake.org

You need to build LLVM 12.0.0 on Windows with x32 target and MD CRT linking

Note: It takes 30-60 minutes to compile, 23 GB of free disk space

Download from LLVM github releases

# Unpack to path without spaces 
tar -xJf llvm-12.0.0.src.tar.xz
# Create build directory
mkdir build
cd build
# Configure 
cmake -DCMAKE_INSTALL_PREFIX=C:/LLVM -DLLVM_USE_CRT_DEBUG=MD -DLLVM_TARGETS_TO_BUILD="X86" -Thost=x86 -A Win32 ../llvm-12.0.0.src/
# Build
cmake --build .
# Install to CMAKE_INSTALL_PREFIX
cmake --build . --target install

Full guide: Building LLVM with CMake

Debian

sudo apt install llvm-12-dev:i386

Other

Checkout this for more info.

Compiling

Windows

# PowerShell
$env:LLVM_SYS_120_PREFIX = "C:\LLVM" # LLVM prefix specified before
cargo build --target i686-pc-windows-msvc
cargo test --target i686-pc-windows-msvc -- --test-threads=1

Linux

cargo build --target i686-unknown-linux-gnu
BYOND_PATH="~/byond" cargo test --target i686-unknown-linux-gnu -- --test-threads=1

See also

DM Opcode relative frequency table

opcode_counts.txt

License

dm-jitaux is licensed under the AGPL-3.0 License. See LICENSE for more details.