GccEmacs refers to the
feature/native-comp branch of Emacs, which adds support for compiling EmacsLisp to native code using
libgccjit. All of the Elisp packages shipped with Emacs are native-compiled, providing a noticeable performance improvement out-of-the-box. Third-party packages are also compiled to achieve further performance improvements.
The official development log can be found on the gccemacs page.
To build the native-comp branch of Emacs, you will need
libgccjit in addition to the other dependencies described in BuildingEmacs.
First, checkout the
feature/native-comp branch of Emacs, and configure it with the
$ git clone git://git.savannah.gnu.org/emacs.git -b feature/native-comp $ cd emacs $ ./autogen.sh $ ./configure --with-nativecomp $ make -j$(nproc)
You should see "Does Emacs have native lisp compiler? yes" near the end of the configure output if native compilation has been enabled.
If you wish, install conventionally with
make install otherwise run it from the build tree with
emacs-native-comp-git package is available on the AUR.
Install it with your favourite AUR helper, or use the following commands to do it yourself:
$ git clone https://aur.archlinux.org/emacs-native-comp-git.git $ cd emacs-native-comp-git $ makepkg --syncdeps --install
systemctl --user start emacs.service immediately crashes and
journalctl --user -u emacs mentions a long path mentioning
native-lisp and ending with
.eln, add the following line to the
[Service] section in
emacs-native-comp package is available in this channel.
Add the channel to your
~/.config/guix/channels.scm, or use the following commands to install it as a one-off:
$ git clone https://github.com/flatwhatson/guix-channel.git $ guix install --load-path=./guix-channel emacs-native-comp
emacsGcc package is available from the Nix community’s Emacs overlay.
Detailed installation instructions are available in this Gist.
By default Emacs ships only native compiling the files included in the Emacs image.
The native compilation of the remaining Emacs distribution and external packages happen automatically and asynchronously (See Deferred compilation).
Deferred compilation refers to "just-in-time" native compilation of Elisp. When a byte-compiled Elisp module is loaded, it gets queued for native compilation. Once native compilation has finished, the native-compiled definitions automatically replace the byte-compiled versions.
This is simple to use as it does not require any user intervention. You may prefer an "ahead-of-time" solution described further below.
Deferred compilation is enabled by default and controlled by the
Sometimes it is useful to compile ahead-of-time, for example if you are packaging Emacs for others.
It is possible to native compile ahead-of-time all the Emacs distribution using the
NATIVE_FULL_AOT, for example:
$ make NATIVE_FULL_AOT=1 -j$(nproc)
The built-in package manager package.el supports ahead-of-time native compilation when installing a package. Customize the user option
‘package-native-compile’ or add this to your init file to enable it:
(setq package-native-compile t)
Some third-party package managers also support ahead-of-time native compilation:
You can native-compile your packages manually:
;; native-compile all Elisp files under a directory (native-compile-async "/path/to/packages" 'recursively)
This will add all Emacs Lisp files under that directory to the queue for asynchronous native compilation.
If you are running native compilation from a script, you will need to block the Emacs process until the async jobs have completed:
;; block until native compilation has finished (while (or comp-files-queue (> (comp-async-runnings) 0)) (sleep-for 1))