Enable just-in-time compilation for improved performance. May prevent use of some PaX memory protection features in Gentoo Hardened.

Packages describing “jit” as local USE flag

Package“jit” Flag Description
app-editors/emacsCompile with Emacs Lisp native compiler support via libgccjit
app-emulation/aranymBuild Just-In-Time compiler variant with increased performance
dev-lang/moarvmEnable Just-In-Time-Compiler. Has no effect except on AMD64 and Darwin.
dev-lang/phpEnable PCRE JIT support
dev-lang/pythonEnable experimental Just-In-Time compilation support.
mail-filter/rspamdEnable PCRE JIT support
net-proxy/privoxyEnable PCRE jit (recommended)
sci-libs/XNNPACKBuild with JIT micro-kernels
sys-devel/gccEnable libgccjit so other applications can embed gcc for Just-In-Time compilation.
www-apache/mod_securityAdd support for the PCRE Just-in-Time optimisation, as enabled by dev-libs/libpcre with jit USE flag enabled. Might not be available on hardened systems.

All packages providing a “jit” USE flag (9)