[PATCH] IndVarSimplify does not check if loop invariant expansion can trap

[James Molloy]

Hi Rafael,

I don't know. Do we know this broken optimization doesn't kick in in the
test suite? If it does, we'd regress on performance if we took the
conservative way out.

Just my 2c.

Cheers,

James

On 4 June 2013 15:40, Rafael Espíndola <rafael.espindola at gmail.com> wrote:

> On 4 June 2013 09:49, James Molloy <james at jamesmolloy.co.uk> wrote:
> > Hi David,
> >
> > Might a more performant solution not be to wrap any hoisted instructions
> > that are not safe to expand in a conditional that tests if the loop will
> be
> > entered at least once?
>
> Is that really worth it? Given that this bug went undetected for years
> (it was already broken in r122610), I don't think it would kick often
> enough to justify it.
>
> Cheers,
> Rafael
>
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