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by dwattttt 153 days ago
Optimising out TLS isn't going to be a good example of compiler capability. Whether another thread exists is a global property of a process, and beyond that the system that process operates in.

The compiler isn't going to know for instance that an LD_PRELOAD variable won't be set that would create a thread.
1 comments
oguz-ismail2 153 days ago
> Whether another thread exists is a global property of a process, and beyond that the system that process operates in.

TLS is a language feature. Whether another thread exists doesn't mean it has to use the same facilities as the main program.

> The compiler isn't going to know for instance that an LD_PRELOAD variable won't be set that would create a thread.

Say the program is not dynamically linked. Still no?

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dwattttt 153 days ago
> Say the program is not dynamically linked. Still no?

Whether the program has dynamic dependencies does not dictate whether a thread can be created, that's a property of the OS. Windows has CreateRemoteThread, and I'd be shocked if similar capabilities didn't exist elsewhere.

If I mark something as thread-local, I want it to be thread-local.

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