Comment by userbinator | Hacker News Reader

Comment by userbinator | Hacker News Reader

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Such rants have not achieved the desired effect. On the contrary, compiler writers have given notice that they will continue exploiting the liberties granted by the language standards.

That suggests to me that the opposition to this exploitation needs to be even stronger...

To take this whole discussion in a philosophical direction, I see the two sides of the argument as having a real-world analogy to laws vs. morals and ethics. The current attitude popular amongst compiler writers is that of strict legality; the term "language-lawyering" certainly applies. But like the real-life analogy, what is legal is not necessarily moral or ethical, and vice-versa. There's a lot of discussion on other topics, here and elsewhere, where that idea is highly debated --- someone will post something along the lines of "but what they're doing is legal", and then many replies will elaborate why that is still wrong.

Yet for some reason, when C and UB comes up, for some reason it seems not agreeing with those ruthlessly exploiting the standard and belittling everyone who dares question them is a highly unpopular and controversial opinion?

> The current attitude popular amongst compiler writers is that of strict legality; the term "language-lawyering" certainly applies.

The difference is that morality is inherently subjective whereas a programming language is pretty much the exact opposite - it is /exactly/ defined by its specification. You may disagree with the design of the language (which is subjective), but that is strictly different from "language-lawyering" and determining what is and isn't allowed by the specification as it is objectively written.

> Yet for some reason, when C and UB comes up, for some reason it seems not agreeing with those ruthlessly exploiting the standard and belittling everyone who dares question them is a highly unpopular and controversial opinion?

Barring the rather unreasonable characterisation of compiler writers as "exploiting" and "belittling" developers, if people have a problem with compiler writers optimizing to the extents allowed by the programming language, then the place to voice these concerns is not through opposition to the compiler writers (who are just doing their job), but to the standards committee writing the specification for the language.

Because wanting the fastest code possible is a big reason to use C over some other language, and such aggressive optimizations that break incorrect code are how you get the fastest code possible.

My experience with ICC and MSVC contradict that, as well as with handwritten Asm. Instruction selection and scheduling matters far more than trying to be too clever with exploiting UB (and they will remove things like overflow checks, albeit they seem to prove more than assume.)

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