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Re: [PATCH] Kill TREE_OVERFLOW during gimplification


Richard Guenther wrote:
> On Thu, Oct 16, 2008 at 3:39 PM, Paolo Bonzini <bonzini@gnu.org> wrote:
>>> As TREE_OVERFLOW happens to be an optimization
>>> barrier in many cases, this helps getting rid of missed optimizations.
>>> Still, any folding during gimple passes that doesn't go through gimplifier
>>> on the result may introduce again TREE_OVERFLOW constants, but this at least
>>> decreases their number.  Bootstrapped/regtested on x86_64-linux, during
>>> make check this triggered 1355 times.
>> You can also try changing all the occurrences of
>>
>>   TREE_OVERFLOW (t) = 1;
>>
>> in fold-const.c into
>>
>>   TREE_OVERFLOW (t) = in_gimple_form;
> 
> This will very likely break at least VRP.

But VRP sets TREE_OVERFLOW in vrp_int_const_binop, doesn't it?

Paolo


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