I expect an infinite loop to be compiled into, for instance, a jump instruction jumping to itself. The OS, if there is any, is welcome to interrupt and context switch. I don't expect code that has no function calls at all to have a system call inserted into it.

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leni536 7 hours ago | parent | next [-]

A call to a standard library function is still subject to the as if rule. It doesn't have to manifest into a call instruction to a standard library function. Much like memcpy in source code doesn't have to manifest to a call instruction.

	▲	fc417fc802 4 hours ago \| parent [-]
		Me: I don't expect to be stabbed. You: But you only might be stabbed. It isn't required to happen only permitted.

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marcosdumay 8 hours ago | parent | prev [-]

Ok, I get this.

The problem is that what you want is completely against the spirit of the entire language.

If your point is that C++ should be more like C in general, I can agree with that. But if your point is that C++ should be literal on this specific case, performance be damned, and the rest of it is ok, then no, that's a bad one.

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JoshTriplett 8 hours ago | parent [-]

I was utterly unconvinced that the original infinite-loop UB gave the compiler any important performance optimization, and I'm unconvinced that this is providing useful value to compensate for its surprise. If I wanted a yield in my infinite loop, I'd add one.

	▲	mitxela an hour ago \| parent [-]
		The original UB was to allow the compiler to merge two loops without proving termination.