Re: [ANN] Lua 5.4.0 (alpha-rc2) now available

[Roberto Ierusalimschy <roberto@...>]

> The well-defined semantics of division by zero are part of Annex F of the C
> specification, which is an optional thing that compilers are not required
> to implement. In the absence of Annex F, division by zero has undefined
> behavior. C++ doesn't have anything like Annex F and division by zero is
> stated to be undefined (although they mention in a non-normative comment
> that most implementations allow the behavior to be controlled using library
> functions).
> 
> A division by zero could result in a trap, exception, or signal such as
> SIGFPE. The convention has been to move away from those behaviors because
> it's convenient to use 1.0/0 as a way to get infinity, but unless Lua's
> documentation specifically requires that you don't do that, nothing stops
> you from passing a compiler flag or calling a library function to change
> that.

That part I know. C is not required to implement IEEE arithmetic (as it
is not required to use 2-complement integers). But repeating my original
question, does anyone know of real platforms where this may cause real
problems? Lua always has allowed division by 0 and we have never got any
report about problems there.

-- Roberto