d6c57eb957
This replaces the OpCode enum with a new Op enum which is guaranteed to fit in a
single byte. Instead of carrying enum variants with data, every variant that has
runtime data encodes it into the `Vec<u8>` that a `Chunk` now carries.
This has several advantages:
* Less stack space is required at runtime, and fewer allocations are required
while compiling.
* The OpCode doesn't need to carry "weird" special-cased data variants anymore.
* It is faster (albeit, not by much). On my laptop, results consistently look
approximately like this:
Benchmark 1: ./before -E '(import <nixpkgs> {}).firefox.outPath' --log-level ERROR --no-warnings
Time (mean ± σ): 8.224 s ± 0.272 s [User: 7.149 s, System: 0.688 s]
Range (min … max): 7.759 s … 8.583 s 10 runs
Benchmark 2: ./after -E '(import <nixpkgs> {}).firefox.outPath' --log-level ERROR --no-warnings
Time (mean ± σ): 8.000 s ± 0.198 s [User: 7.036 s, System: 0.633 s]
Range (min … max): 7.718 s … 8.334 s 10 runs
See notes below for why the performance impact might be less than expected.
* It is faster while at the same time dropping some optimisations we previously
performed.
This has several disadvantages:
* The code is closer to how one would write it in C or Go.
* Bit shifting!
* There is (for now) slightly more code than before.
On performance I have the following thoughts at the moment:
In order to prepare for adding GC, there's a couple of places in Tvix where I'd
like to fence off certain kinds of complexity (such as mutating bytecode, which,
for various reaons, also has to be part of data that is subject to GC). With
this change, we can drop optimisations like retroactively modifying existing
bytecode and *still* achieve better performance than before.
I believe that this is currently worth it to pave the way for changes that are
more significant for performance.
In general this also opens other avenues of optimisation: For example, we can
profile which argument sizes actually exist and remove the copy overhead of
varint decoding (which does show up in profiles) by using more adequately sized
types for, e.g., constant indices.
Known regressions:
* Op::Constant is no longer printing its values in disassembly (this can be
fixed, I just didn't get around to it, will do separately).
Change-Id: Id9b3a4254623a45de03069dbdb70b8349e976743
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12191
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
|
||
|---|---|---|
| .gcroots | ||
| .nixery | ||
| corp | ||
| docs | ||
| fun | ||
| lisp | ||
| net | ||
| nix | ||
| ops | ||
| third_party | ||
| tools | ||
| tvix | ||
| users | ||
| views | ||
| web | ||
| .envrc | ||
| .git-blame-ignore-revs | ||
| .gitignore | ||
| .hgignore | ||
| .mailmap | ||
| .rgignore | ||
| buf.gen.yaml | ||
| buf.yaml | ||
| default.nix | ||
| LICENSE | ||
| OWNERS | ||
| README.md | ||
| RULES | ||
| rustfmt.toml | ||
depot
This repository is the monorepo for the community around The Virus Lounge, containing our personal tools and infrastructure. Everything in here is built using Nix.
A large portion of the software here is very self-referential, meaning that it exists to sustain the operation of the repository. This is the case because we partially see this as an experiment in tooling for monorepos.
Highlights
Services
-
Source code is available primarily through Sourcegraph on cs.tvl.fyi, where it is searchable and even semantically indexed. A lower-tech view of the repository is also available via cgit-pink on code.tvl.fyi.
The repository can be cloned using
gitfromhttps://cl.tvl.fyi/depot. -
All code in the depot, with the exception of code that is checked in to individual
//usersfolders, needs to be reviewed. We use Gerrit on cl.tvl.fyi for this. -
Issues are tracked via our own issue tracker on b.tvl.fyi. Its source code lives at
//web/panettone/. -
Smaller todo-list entries which do not warrant a separate issue are listed at todo.tvl.fyi.
-
We use Buildkite for CI. Recent builds are listed on tvl.fyi/builds and pipelines are configured dynamically via
//ops/pipelines. -
A search service that makes TVL services available via textual shortcuts is available: atward
All services that we host are deployed on NixOS machines that we manage. Their
configuration is tracked in //ops/{modules,machines}.
Nix
//nix/readTreecontains the Nix code which automatically registers projects in our Nix attribute hierarchy based on their in-tree location//tools/nixerycontains the source code of Nixery, a container registry that can build images ad-hoc from Nix packages//nix/yantscontains Yet Another Nix Type System, which we use for a variety of things throughout the repository//nix/buildGoimplements a Nix library that can build Go software in the style of Bazel'srules_go. Go programs in this repository are built using this library.//nix/buildLispimplements a Nix library that can build Common Lisp software. Currently only SBCL is supported. Lisp programs in this repository are built using this library.//web/blogand//web/atom-feed: A Nix-based static site generator which generates the web page and Atom feed for tazj.in (//users/tazjin/homepage) and tvl.fyi (//web/tvl)//web/bubblegumcontains a CGI-based web framework written in Nix.//nix/nint: A shebang-compatible interpreter wrapper for Nix.//tvixcontains initial work towards a modular architecture for Nix.
We have a variety of other tools and libraries in the //nix folder which may
be of interest.
Packages / Libraries
//net/alcoholic_jwtcontains an easy-to-use JWT-validation library for Rust//net/crimpcontains a high-level HTTP client using cURL for Rust//tools/emacs-pkgscontains various useful Emacs libraries, for example:dottime.elprovides dottime in the Emacs modelinenix-util.elprovides editing utilities for Nix filesterm-switcher.elis an ivy-function for switching between vterm bufferstvl.elprovides helper functions for interacting with the TVL monorepo
//lisp/klatreprovides a grab-bag utility library for Common Lisp
User packages
Contributors to the repository have user directories under
//users, which can be used for
personal or experimental code that does not require review.
Some examples:
//users/aspen/xanthous: A (WIP) TUI RPG, written in Haskell.//users/tazjin/emacs: tazjin's Emacs & EXWM configuration//users/tazjin/finito: A persistent finite-state machine library for Rust.
Licensing
Unless otherwise stated in a subdirectory, all code is licensed under the MIT license. See LICENSE for details.
Contributing
If you'd like to contribute to any of the tools in here, please check out the contribution guidelines and our code of conduct.
IRC users can find us in #tvl on hackint, which is also
reachable via XMPP at #tvl@irc.hackint.org (sic!).
Hackint also provide a web chat.