Add just-in-time (jit) language option to gcc build (T9679)

[celticmagic]

appmath (#appmath), 2021-04-14 11:43:11 UTC

The currently in development and upcoming Emacs 28 release has merged gccemacs. This feature adds support for compiling Emacs Lisp to native code using libgccjit resulting (hopefully) in greatly improved run-time performance.

Adding --enable-languages=jit,(etc) to the gcc build provides libgccjit.so.

[celticmagic]

Beatrice T. Meyers (#DataDrake), 2021-04-22 22:19:54 UTC

At the moment nothing requires this so it doesn't need to happen until emacs is updated to 28.X.

[celticmagic]

nazar (#nazar), 2021-05-19 05:29:18 UTC

! In T9679#183794, #DataDrake wrote: At the moment nothing requires this so it doesn't need to happen until emacs is updated to 28.X.

enabling libgccjit would make absolutely easier compiling 28.0 branch for those who use pre-release version of emacs.

[celticmagic]

Joshua Strobl (#JoshStrobl), 2021-05-19 12:13:03 UTC

branch for those who use pre-release version of emacs.

Not sure why we should need to be the ones to put in the work for that then.

[ermo]

This is a pretty nice option to have, particularly given the fact that e.g. emacs is notoriously slow and enabling this option will speed things up a fair bit.