Covers the right sort of thing. It makes a guess at what a function call will be, inlined that guess, and if it turned out to be wrong restarts from the start of the function in the interpreter. Doesn't explicitly call out the function calling convention but guarded inlining has much the same effect.

Maybe worth noting that inlining a fexpr is semantically very close to expanding a macro. Identical if symbol renaming is done the same way for each.