openwrt/package/libs/pcre/Config.in

config PCRE_JIT_ENABLED
	bool
	depends on PACKAGE_libpcre && (arm || i386 || i686 || x86_64 || mips || mipsel || powerpc || sparc)
	default y if (arm || i686 || x86_64)
	prompt "Enable JIT compiler support"
	help
		Enable JIT (Just-In-Time) compiler support.

		Enabling this option can give an about 10x performance increase on JIT operations. It can be desireable for e.g. high performance Apache mod_rewrite or HA-Proxy reqrep operations.

		However, JIT should _only_ be enabled on architectures that are supported. Enabling JIT on unsupported platforms will result in a compilation failure. A list of supported architectures can be found here: https://pcre.org/original/doc/html/pcrejit.html#SEC3 .