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
dev-lang/moarvm Enable Just-In-Time-Compiler. Has no effect except on AMD64 and Darwin.
sci-libs/XNNPACK Build with JIT micro-kernels
www-apache/mod_security Add 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.
mail-filter/rspamd Enable PCRE JIT support
sys-devel/gcc Enable libgccjit so other applications can embed gcc for Just-In-Time compilation.
sci-electronics/nvc Enable experimental JIT complilation with LLVM
dev-lang/php Enable PCRE JIT support
app-emulation/aranym Build Just-In-Time compiler variant with increased performance
app-editors/emacs Compile with Emacs Lisp native compiler support via libgccjit
net-proxy/privoxy Enable PCRE jit (recommended)

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