JIT parameter in createTargetMachine

Dear all,

what does the parameter ‘JIT’ mean in Target::createTargetMachine ? It is not documented here:


I have ported a rather old code base from llvm 3.x to 7.0 and now I might be observing a performance regression. I stumbled upon this new parameter when changing the codemodel and wondered whether it should be set to false or true (we use a JIT execution engine).



Hi Christoph,

If your TargetMachine is being used to generate JIT’d code then the JIT argument should be set to ‘true’.

What target/code-model are you using? Were you able to confirm your regression?