How much overhead is there in calling a function in C++?

Question

A lot of literature talks about using inline functions to \"avoid the overhead of a function call\". However I haven\'t seen quantifiable data. What is the actual overhead o

Answer 1

It's worth pointing out that an inlined function increases the size of the calling function and anything that increases the size of a function may have a negative affect on caching. If you're right at a boundary, "just one more wafer thin mint" of inlined code might have a dramatically negative effect on performance.

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If you're reading literature that's warning about "the cost of a function call," I'd suggest it may be older material that doesn't reflect modern processors. Unless you're in the embedded world, the era in which C is a "portable assembly language" has essentially passed. A large amount of the ingenuity of the chip designers in the past decade (say) has gone into all sorts of low-level complexities that can differ radically from the way things worked "back in the day."