alt Hacker News> C is not like that, and calling into an external module necessarily grows the stack.
This is because of the calling convention, yes? (and to some extent, if you want an accurate stack trace, but I find it acceptable that TCO also includes stack trace erasure)
Yyyyes... But like I said, TCO cannot make use of the calling convention, because it doesn't involve calling. That means you can't have TCO loops crossing module boundaries (or function pointers for that matter). So we're back to my original question: what does it matter what the calling convention is if the compiler has the liberty to compile both functions however it pleases?