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But if you're using volatile correctly, then there's nothing wrong with ++*v.

I was wondering about that slide that says the meaning is unclear, I don't see what's unclear about it. What particular assembly instructions it translates into is irrelevant. It's not like ++ is guaranteed atomic or anything.

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it's not guaranteed atomic, and if you ARE using volatiles, "maybe" doesn't really cut it, so now you need to do `++*v` the proper way (ex. `lock cmpxchg` / `__atomic_compare_exchange`), or explicitly write it out the long way (`*v = *v + 1`) and risk the small chance of the value changing under you between read/write

using volatile correctly usually means you're manipulating write-combining memory.

Write-combining memory has weak memory ordering where all writes are delayed so anything doing both reads and writes is most likely going to bite you in the neck.

If you're accessing any kind of I/O register or special memory, obviously you need to know the rules of engagement for the particular kind. If you don't, then you're just going to be making the same mistake in a less obvious guise. Like writing *v=*v+1 instead of *v++.

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