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One thing that was a little annoying was their discussion about purpose of undefined behavior. Could you quote an offending passage that claims that the purpos
by pohl 15y ago
One thing that was a little annoying was their discussion about purpose of undefined behavior.
Could you quote an offending passage that claims that the purpose of undefined behavior is for speed? I see discussion of how undefined behavior creates opportunities for optimization, but nothing about purpose. Indeed, the word "purpose" does not appear in parts 1, 2, or 3 at all.
So please share whatever passage has the semantics you claim.
It may be the llvm folks bypass this point because llvm is "virtual machine" rather than a chip.
I'm curious: what exactly do you mean by this?
I don't mean to be rude, but whenever I read anybody say that LLVM is a virtual machine, it always comes off as if everything they know about LLVM came from learning the acronym.
- joe_the_user 15y agoPohl: Could you quote an offending passage that claims that the purpose of undefined behavior is for speed? Me: How a-bout, "Undefined behavior exists in C-based languages because the designers of C wanted it to be an extremely efficient low-level programming language."*?? Seems pretty clear. You don't necessarily need the literal term "purpose" here - the term "because" in this passage implies purpose (http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html http://blog.llvm.org/2011/05/what-every-c-programmer-should-... - yes, that's first article, sorry).
- pohl 15y agoI see, it's a historical claim without a citation. What kind of machine was it back then, a PDP-11? I suppose it's possible they would want to save cycles here & there. Do you know something specific about the history here?