"Cost" of calling a function

[szlamany]

I am curious what the physical "cost" is of calling a function. What really happens to memory when that function is called.

Let's say I've got a complicated loop running in code - and I want to take the "contents" of that loop logic and put it in another C++ function.

If the "variables" and what-not (I've got large arrays and "strings" passed from "managed" code here as well) are all passed by REFERENCE - so no memory is copied for that what is other costs involved?

Is there a GOSUB-like or JSB-like statement in C++ that could help me visually organize this code without incurring the cost of calling functions??

[Siddharth Rout]

Moved to C++ Forum from C++ Codebank.

[jmcilhinney]

You might want to have a look at this and perhaps investigate further along that line.

http://www.codeproject.com/Articles/...with-the-stack

[szlamany]

Thank you - that was a great read.

I'm doing loops on 500,000+ byte chunks of memory representing the text of documents. Each character is passed through lots of conditions and also looked at against arrays of rules.

It's that moment of looking at the arrays of rules that I was thinking of removing to a separate function body - passing in whatever is needed by reference. I can see from that article how the stack builds up when that happens.

I was concerned because I was looking at it from the "outside" - where the big loop on the memory chunk is being done. But actually the amount of code running against the array of rules is huge and adding on some stack-framing requirements is most likely inconsequential to the run time.

Bottom line is I can benchmark and time this myself - and I probably should.