https://github.com/pcercuei/lightrec

MIPS-to-everything dynamic recompiler for PSX emulators
https://github.com/pcercuei/lightrec

c dynarec emulators jit mips playstation

Last synced: about 1 month ago
JSON representation

MIPS-to-everything dynamic recompiler for PSX emulators

• Host: GitHub
• URL: https://github.com/pcercuei/lightrec
• Owner: pcercuei
• License: other
• Created: 2014-07-29T15:04:39.000Z (about 11 years ago)
• Default Branch: master
• Last Pushed: 2025-08-15T07:49:28.000Z (about 2 months ago)
• Last Synced: 2025-08-15T09:24:45.824Z (about 2 months ago)
• Topics: c, dynarec, emulators, jit, mips, playstation
• Language: C
• Homepage:
• Size: 1.46 MB
• Stars: 160
• Watchers: 12
• Forks: 11
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: COPYING

Awesome Lists containing this project

README

          

# Lightrec

Lightrec is a MIPS-to-everything dynamic recompiler for

PlayStation emulators, using

[GNU Lightning](https://www.gnu.org/software/lightning/)

as the code emitter.

As such, in theory it should be able to run on every CPU that Lightning

can generate code for; including, but not limited to, __x86__, __x86_64__,

__ARM__, __Aarch64__, __MIPS__, __PowerPC__, __SH4__ and __Risc-V__.

## Features

* __High-level optimizations__.  The MIPS code is first pre-compiled into

a form of Intermediate Representation (IR).

Basically, just a single-linked list of structures representing the

instructions. On that list, several optimization steps are performed:

instructions are modified, reordered, tagged; new meta-instructions

can also be added.

* __Lazy compilation__.

If Lightrec detects a block of code that would be very hard to

compile properly (e.g. a branch with a branch in its delay slot),

the block is marked as not compilable, and will always be emulated

with the built-in interpreter. This allows to keep the code emitter

simple and easy to understand.

* __Run-time profiling__.

The generated code will gather run-time information about the I/O access

(whether they hit RAM, or hardware registers).

The code generator will then use this information to generate direct

read/writes to the emulated memories, instead of jumping to C for

every call.

* __Threaded compilation__.

When entering a loading zone, where a lot of code has to be compiled,

we don't want the compilation process to slow down the pace of emulation.

To avoid that, the code compiler optionally runs on a thread, and the

main loop will emulate the blocks that have not been compiled yet with

the interpreter. This helps to drastically reduce the stutter that

typically happens when a lot of new code is run.

## Emulators

Lightrec has been ported to the following emulators:

* [__PCSX-ReArmed__ (libretro)](https://github.com/libretro/pcsx_rearmed)

* [__Beetle__ (libretro)](https://github.com/libretro/beetle-psx-libretro/)

* [__CubeSX/WiiSX__](https://github.com/emukidid/pcsxgc/)

* [__Bloom__](https://github.com/pcercuei/bloom)

[![Star History Chart](https://api.star-history.com/svg?repos=pcercuei/lightrec&type=Date)](https://star-history.com/#pcercuei/lightrec&Date)