When should we use inline=True in jax.jit?

[nasyxx]

According to my knowledge, we should make the function inline as much as possible for efficiency. But is it still correct in JAX?

I have some questions about this. For example, I have the following two functions:

def f1(x):
     return x + 1

def f2(x):
     return f1(x) + 1

Is it the same between inline jit f1, then jit f2, and only jit f2?

[hawkinsp]

The only effect inline=True will have is making the IR smaller if you have a trivial function, really. We added it mostly so our internal jitted functions like + don't gum up the IR with many little function calls.

Given our current compiler (XLA) eventually inlines everything anyway, I would basically ignore it for the moment.

[soraros]

I've seen latest development in XLA like #1728. Does this mean inline can do something more interesting in the future?