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Re: [perl #76438] peephole optimiser could prune more dead code

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Ævar Arnfjörð Bjarmason
July 13, 2010 06:11
Re: [perl #76438] peephole optimiser could prune more dead code
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On Tue, Jul 13, 2010 at 11:43, Ben Morrow <> wrote:
> Perl doesn't have undefined behaviour. No matter what weasel words
> copied from stdc made it into the ++ docs, Perl's actual evaluation
> order has always been straightforward and well-defined. Changing this
> may be worth it, for a sufficiently beneficial optimisation, but it is
> definitely a backwards-incompatible change.

Undefined doesn't mean that the implementation doesn't act
consistently, just that its documentation explicitly denies
responsibility for having those things work in the future. If they
work now they only work incidentally, and you shouldn't rely on them.

Of course we can't liberally change things that are documented to be
undefined as liberally as a C compiler would, becuase there's only one
perl(1) but multiple cc(1)'s.

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